Nathan BALL
Powered Rope Ascender

Atlas Power
Ascender
The Atlas Power Ascender, now known in the U.S. Military as
the APA, is a powerful tool that enables “reverse
rappelling” up buildings and other vertical surfaces at
unprecedented speeds.
Using Atlas Devices' patented rope interaction design, the
lightweight APA can pull a fully-loaded soldier or
firefighter up a rappelling line at up to 10 ft/sec, as well
as tow vehicles and even remotely move equipment and
casualties.
With the capability to reach the top of a building or cliff
in only seconds, new advantages are gained in urban warfare,
rescue operations, industrial access, and beyond.
www.Wikipedia
Nathan Ball

Nathan "Nate" Barker Ball (born May 13, 1983 in Newport, Oregon)
works as a host on the PBS Kids show Design Squad. Ball has
appeared in an episode of Myth Busters, a History Channel
special on Batman technology, in an insurance advertisement, and
in a FETCH! with Ruff Ruffman season 4 episode.
He holds two degrees in mechanical engineering from
Massachusetts Institute of Technology, a B.S. (2005) and an M.S.
(2007).
He won the Lemelson-MIT Prize in 2007.
He co-founded a business to develop the ATLAS Powered Rope
Ascender, a tool he helped create that enables "reverse
rappelling" up vertical surfaces at high speed.[1]
He is listed as the co-inventor on 6 patent applications. [2][3]
He is a two-time NCAA All-American pole-vaulter and MIT’s
outdoor record holder in the sport, with a record jump of 16' 8
¾".[4][5]
http://web.mit.edu/invent/a-winners/a-ball.html
Nathan
Ball
Nathan "Nate" Ball's passion for invention was coursing through
his veins long before he could define the word. He recalls
digging up the family garden at two years old to build, wreck
and rebuild mud dams and underground forts. In fourth grade he
created a bottle-rocket launcher that shot two-liter bottles of
water 100 feet skyward. This was followed by a hovercraft
powered by a vacuum cleaner motor that he constructed in sixth
grade.
By the time Ball was in the eighth grade, he was attempting to
build a Tesla coil in his parent's garage, making capacitors out
of glass bottles and aluminum foil. "I saw Tesla coils on the
Internet shooting lightening," said Ball. "It was the coolest
thing I'd ever seen, and I knew I had to build one."
Amazingly, Ball never touched a machine tool until he reached
college. He credits limited resources during his formative years
to his ability to think unconventionally about problems and
engineer efficient solutions.
Now 23, Ball is pursuing his Master of Science in Mechanical
Engineering at the Massachusetts Institute of Technology and
intends to graduate in 2007. He earned his Bachelor of Science
in Mechanical Engineering from MIT in 2005.
He currently researches his master's thesis at MIT's
BioInstrumentation Laboratory, which is run by his advisor,
Hatsopoulos Professor of Mechanical Engineering Ian W. Hunter.
Under Hunter and Research Scientist Andrew Taberner, another
advisor, Ball was challenged to use the lab's novel
Lorentz-force actuator to create a dual-action, rapid-fire
delivery technology that increased drug volume delivery, which
he created within two months.
Now awaiting livestock trials, Ball and his colleagues
anticipate the needle-free injection technology having
applications in animal husbandry, and they hope it may someday
be employed for safe, inexpensive, mass inoculation of humans in
developing and developed countries. Commercialization of the
work is funded in part by partner Norwood Abbey, Inc. of
Melbourne, Australia.
Additionally, in 2004, Ball founded Atlas Devices, LLC with
three other mechanical engineering students at MIT to develop
and commercialize the ATLAS Powered Rope Ascender, which uses a
rope-handling mechanism conceived by Ball. This portable device
can raise more than 250 pounds at 10 feet per second, giving
rescuers, emergency personnel and soldiers faster and more
controllable climbing capabilities. The U.S. Army recently
awarded funding for their invention.
Ball is a co-applicant of six patents and the co-author of
numerous peer-reviewed articles. His awards and achievements
include the SAIC Award in the 2005 Soldier Design Competition,
sponsored by the Institute for Soldier Nanotechnologies at MIT,
for his team's ATLAS Powered Rope Ascender. He also won the Luis
DeFlorez Award for outstanding ingenuity and creativity from
MIT's Department of Mechanical Engineering in 2005 for an
electric scooter.
Inspired by his mother, who is a music teacher, and father, who
is an engineer, Ball also enjoys sharing his passion for science
and invention with others. In February 2007, Ball will be
featured as a mentor to eight budding engineers as co-host of
PBS’s new series "Design Squad." The show aims to excite
middle-school students about science and engineering by
combining elements of reality TV with fun and educational
engineering challenges. Additionally, Ball also mentors fifth
grade boys in science and engineering at Fletcher Maynard
Academy in Cambridge, Mass.
Ball is a native of Newport, Oregon where he was raised with his
two sisters. He is a two-time NCAA All-American pole-vaulter and
MIT’s indoor/outdoor record holder in the sport (16' 6" indoor,
16' 8 ¾" outdoor). He currently serves as the school's head pole
vault coach.
Ball is also trained in classical piano. For fun, he enjoys
playing jazz keyboard and beat-boxing.
Current Update:
Ball received his M.S. (2007) and B.S. (2005) in mechanical
engineering at the Massachusetts Institute of Technology. For
his master's thesis at MIT's BioInstrumentation Laboratory, Ball
was challenged by advisors, Hatsopoulos Professor of Mechanical
Engineering Ian W. Hunter and Research Scientist Andrew
Taberner, to use the lab's novel Lorentz-force actuator to
create a dual-action, rapid-fire delivery technology that
increased drug volume delivery, which he created within two
months.
http://web.mit.edu/invent/n-pressreleases/n-press-07SP.html
MIT GRADUATE
STUDENT WINS $30,000 LEMELSON-MIT STUDENT PRIZE FOR LIFE-SAVING
INVENTIONS
Nathan Ball's inventions include a
device to "fly" to tops of buildings and another to
significantly improve mass inoculations
CAMBRIDGE, Mass. (February 14, 2007) – The ability to leap tall
buildings in a single bound used to be the stuff of comic-book
fantasy. Nathan Ball, a 23-year-old graduate student at the
Massachusetts Institute of Technology and this year’s winner of
the $30,000 Lemelson-MIT Student Prize, has invented a device
that makes the fantasy a reality.
With the help of Ball's ATLAS Powered Rope Ascender, a fully
loaded firefighter could reach the top of a 30-story building in
only 30 seconds, compared to the six minutes or more it often
takes to trudge up stairs with 80 to 100 pounds of equipment.
The device, which is the size of a hand-held power tool, can
lift a 250-pound load more than 600 feet into the air at nearly
10 feet per second, all on a single battery charge.
"Ingenuity, creativity and passion seem to course through Nate's
blood," said Merton Flemings, director of the Lemelson-MIT
Program, which sponsors the annual award. "His battery-powered
rope ascender and needle-free injection technology both have
life-saving capabilities and many commercial applications."
"Nate is also an inspiring and committed mentor for young
inventors. This combination of attributes made him our top
choice for this year’s $30,000 Lemelson-MIT Student Prize,"
Flemings added.
Up, Up and Away!
In November 2004, Ball and three colleagues entered the Soldier
Design Competition sponsored by the MIT Institute for Soldier
Nanotechnologies. The competition called for a high-powered
device to enable rapid vertical mobility.
Ball called the challenge unprecedented, as the original
specifications called for a device that weighed less than 25
pounds and could lift 250 pounds 50 feet into the air, in five
seconds. "That's more than five horsepower in a 25-pound
package," he explained. "That's a power-to-weight ratio higher
than a Dodge Viper's — we did the math. To have that much power
in that small of a package is a heck of a challenge."
Through a combination of resourcefulness and "the highest-tech
equipment we could afford," such as drill batteries and a few
high-power density motors, Ball and his colleagues invented a
device that could hoist 250 pounds of weight 50 feet into the
air in seven seconds — only two seconds slower than the
competition's specification.
The novel aspect of the ATLAS
ascender is its rope-handling mechanism. Similar to the way an
anchor is raised and lowered on a ship, the device relies on
the capstan effect, which produces a tighter grip each
consecutive time a rope is wrapped around a cylinder. The grip
continues to tighten as more weight is applied to the line.
In his design, a standard-sized rope (between three-eighths and
five-eighths of an inch) is weaved between a series of specially
configured rollers that sit on top of a turning spindle. As the
battery-powered spindle rotates, it continuously pulls rope
through the device. "We currently have three patents pending for
the rope interaction and other iterations on the device" said
Ball.
Ball and his colleagues founded Atlas Devices, LLC to develop
and market the ATLAS Powered Rope Ascender. He has upgraded the
original design, and the device is now powered by high-density,
lithium-ion batteries created by A123Systems. Ball said the new
power system immediately dropped the device's weight by several
pounds and significantly increased its speed.
"The latest configuration weighs 20 pounds and peaks at 10 feet
per second," he said. "A123Systems has a 150-foot steam tower we
were able to use for testing. We successfully completed a
100-foot continuous ascent to the tower’s platform in 14
seconds."
Ball envisions his invention having practical applications in
rescue work, recreational climbing and cave exploration, as well
as urban warfare situations. "It can help people complete tasks
more efficiently and without depleting energy they would
otherwise use climbing ladders and carrying heavy gear," he
said.
Hit Me With Your Best Shot
Another of Ball's stand-out inventions is an improvement in the
needle-free injection technology developed at MIT's
BioInstrumentation Laboratory. Under the direction of his
advisors Ian W. Hunter and Andrew Taberner in the
BioInstrumentation Laboratory, Ball was challenged to use the
lab's novel Lorentz-force actuator to create a dual-action,
rapid-fire delivery technology that increased drug volume
delivery.
Within two months, he had not only come up with a solution to
the problem, but had built and tested a prototype device.
"Nate's achievement is simply breathtaking and will have
potentially a huge impact on drug delivery and, hence,
healthcare," said Ball's advisor Professor Hunter.
Now awaiting livestock trials, Ball and his colleagues
anticipate the needle-free injection technology having
applications in animal husbandry. Beyond that, they hope the
device may someday be employed for safe, inexpensive, mass
inoculation of humans in developing and developed countries.
Commercialization of the work is funded in part by partner
Norwood Abbey, Inc. of Melbourne, Australia.
Inventor, Student, Reality-Show
Host
Ball's interest in invention does not stop with his own
creations; he also dedicates himself to mentoring and advising
aspiring inventors.
"Coming from a family of teachers and having such strong support
from my parents, I felt it imperative to share that with other
young inventors," he said. "My parents helped me find my passion
early in life and instilled in me a way to maintain it. To help
other young inventors discover science is amazing and watching
their first moment of discovery is very rewarding."
Ball has been deeply involved as a technical advisor and co-host
of "Design Squad," a new engineering-based reality show for kids
ages 9-13 that will air nationally on PBS beginning in February
2007. He helped brainstorm and test challenge ideas that he said
would "require clever problem solving, ingenuity, and some
classic mess-making." Ball hopes that through this program, kids
will be empowered to explore and embrace the elements of
engineering that surround them each day.
Program Expands to Recognize Other
Exceptional Inventors
In its ongoing effort to expand its reach and recognize
outstanding up-and-coming inventors, the Lemelson-MIT Program is
offering two new $30,000 Student Prizes this year.
Michael Callahan is the inaugural winner of the
Lemelson-Illinois Student Prize at the University of Illinois at
Urbana-Champaign. He is a graduate student in Industrial and
Enterprise Systems Engineering who has invented a method to
intercept neurological signals near the source of vocal
production and convert the signals into speech. He hopes to make
it possible for people with limited speech or movement abilities
to communicate.
On February 16, the first recipient of the Lemelson-Rensselaer
Student Prize at Rensselaer Polytechnic Institute will be
announced by Lemelson Foundation chair Dorothy Lemelson,
Rensselaer President Shirley Ann Jackson and Alan Cramb, dean of
the School of Engineering. Details about the winner will be
posted on www.rpi.edu/lemelson/.
On May 3, the winners of these Student Prizes will join together
for a panel discussion at the Museum of Science, Boston. The
3:00 p.m. panel is open to the public and included in the
Exhibit Hall admission.
About the $30,000 Lemelson-MIT
Student Prize
The $30,000 Lemelson-MIT Student Prize is awarded annually to an
MIT senior or graduate student who has created or improved a
product or process, applied a technology in a new way,
redesigned a system, or demonstrated remarkable inventiveness in
other ways. A distinguished panel of MIT alumni and associates
including scientists, technologists, engineers and entrepreneurs
chooses the winner.
About the Lemelson-MIT Program
The Lemelson-MIT Program recognizes outstanding inventors,
encourages sustainable new solutions to real-world problems, and
enables and inspires young people to pursue creative lives and
careers through invention.
Jerome H. Lemelson, one of the world's most prolific inventors,
and his wife Dorothy founded the Lemelson-MIT Program at the
Massachusetts Institute of Technology in 1994. It is funded by
the Lemelson Foundation, a private philanthropy that celebrates
and supports inventors and entrepreneurs in order to strengthen
social and economic life. More information on the Lemelson-MIT
Program is online at http://web.mit.edu/invent/.
DEVICE TO
ENABLE ROPE PULLING FUNCTIONALITY USING A ROTATIONAL POWER
SOURCE
US2007194290
A device capable of pulling an object (e.g., a person) by or up
a tensioning member (e.g., a rope) is provided. The device can
be configured to mate to any location of the tensioning member,
and subsequently interface with a rotational power source (such
a mechanical drill). Once interfaced, an output of the
rotational energy source can be rotationally coupled to a
rotating drum of the device wherein the drum is in communication
with the tensioning member. With the addition of power, the
drum(s) can pull the tensioning member through the device and
allow for a continuous force to be applied to an object attached
to the device or attached to the tensioning member. The use of
such a convenient and low-cost power source allows for an
economic, portable, and simple to use device capable of lifting
and/or pulling heavy loads.
FIELD OF INVENTION
[0003] This invention relates to devices for moving an object by
pulling on a tensioning member to which the object is attached.
More particularly, the invention relates to a device that
couples to a rotational power source in order to lift or pull
heavy objects by pulling on a rope or cable.
BACKGROUND OF THE INVENTION
[0004] Winches are typically used to lift heavy loads or pull
loads across horizontal obstacles. Winches are either
motor-driven or hand powered and utilize a drum around which a
wire rope (i.e. metal cable) or chain is wound. Manually lifting
or pulling heavy objects is not a viable option due to the
strength required to lift or pull such objects. Often, fatigue
and injury result from manually lifting or pulling such objects.
This is why winches are used; they possess massive pulling and
towing capabilities, and can serve well for handling heavy
objects.
[0005] However, winches are limited in their usefulness for
several reasons. First, the cable or rope is fixed permanently
to the drum, which limits the maximum pull distance and
restricts the towing medium to only that rope or cable. Second,
the winch must be permanently or semi-permanently fixed to a
solid structure to be used, limiting its placement and
usability. Third, controlled release of tension is not a
capability of many winches, further limiting usability.
[0006] As such, there is a need in the art for a versatile,
portable, low cost, and easy to use device capable of lifting or
pulling a load a desired distance and/or height.
SUMMARY OF THE INVENTION
[0007] The presently disclosed embodiments provide devices
capable of lifting or pulling an object (e.g., a person) up or
along a tensioning member (e.g., a rope). More specifically, the
device is capable of mating to any location of the tensioning
member thereby eliminating the need to thread an end of the
tensioning member through the device, and the device is further
capable of being powered by a rotational power source (portable
or fixed) such as a mechanical drill. The use of such a
convenient and low-cost power source allows for an economic,
simple to use, and easy to carry, portable device capable of
lifting and/or pulling heavy loads. Various aspects of the
device are disclosed below.
[0008] In one aspect, the device includes an input for
rotational power wherein the input includes an interface capable
of removably engaging a rotational power source. The rotational
power source can be any device (portable or fixed) capable of
supplying a rotational power to the device. For example, the
rotational power source can include a mechanical power drill, a
hand crank, an air wrench, or any device having a mechanically
powered rotating shaft. Additionally, the device can include a
physical attachment capable of attaching the device to the
rotational power source.
[0009] The device can further include a rope pulling mechanism
which includes at least one rotating drum (or a plurality of
rotating drums) having a longitudinal axis and a circumference,
and a guide mechanism configured to receive a tensioning member
(e.g., a rope). The guide mechanism can be further configured to
guide the tensioning member onto, around at least a portion of
the circumference of, and off of the rotating drum as the drum
rotates. In one embodiment, the longitudinal axis of the
rotating drum is parallel with a longitudinal axis of the
tensioning member thereby allowing the drum to act, in general,
as a capstan. In another embodiment, a plurality of rotating
drums can be utilized wherein the longitudinal axis of each drum
is substantially perpendicular to the longitudinal axis of the
tensioning member thereby allowing the drums to act, in general,
as a pulley system. In an exemplary embodiment, an outer surface
of the rotating drum has a surface characterized by a
anisotropic friction.
[0010] In any of these embodiments, the rotating drum(s) can be
configured to receive an output (i.e., a rotating force) from an
engaged rotational power source capable of rotating the drum at
a desired speed. In response to the output of the rotational
power source, the rotating drum can continuously pull the
tensioning member through the device. The device can couple the
rotating drum to the output of the rotational power source via a
gear box, or the rotating drum can be coupled directly to the
rotational power source.
[0011] The device can include various safety features capable of
locking the device at a desired position along the length of the
tensioning member. For example, the device can include a gearbox
having a worm gear, and/or the device can include a cam-lock
positioned at various locations of the device and in
communication with the tensioning member.
[0012] Additionally, the device can further include an
attachment point capable of attaching an object to the device.
For example, the object can be a person (in the case of lifting
a person along a length of the tensioning member), or the object
can be a non-movable object (such as in the case of utilizing
the device as a portable winch).
[0013] In another aspect, the device can include a rope pulling
mechanism including a rotating drum wherein the rope pulling
mechanism can be coupled to a tensioning member at any position
along a length of the tensioning member thereby eliminating the
need to thread an end of the tensioning member through the
device. Further, the device can include an input for rotational
power which includes an interface capable of removably engaging
a rotational power source. The input can further be configured
to couple an output of the rotational power source (i.e., a
rotational power) to the rope pulling mechanism thereby enabling
the device to apply a tension to the tensioning member in
response to an output from the rotational power source.
[0014] These aspects and others will be discussed in detail
below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The following figures provide illustrative examples of
various embodiments of the present invention. The figures are
not meant in any way to limit the scope of any embodiment of the
presently disclosed devices, systems or methods of use.
[0016] FIG. 1 is a diagrammatic
view of an exemplary embodiment of the presently disclosed
device;
[0017] FIG. 2 is a diagrammatic
view of an alternative embodiment of the presently disclosed
device;
[0018] FIG. 3 is a diagrammatic
side view of an exemplary embodiment of the presently
disclosed device;
[0019] FIG. 4 is a diagrammatic
side view of an alternative embodiment of the presently
disclosed device;
[0020] FIG. 5 is a view of an
exemplary embodiment of a rope-pulling mechanism of the
presently disclosed device;
[0021] FIG. 6A is a view of an
exemplary embodiment of a rotating drum of the rope pulling
mechanism of FIG. 5;
[0022] FIG. 6B is a top view of the
embodiment of FIG. 6A;
[0023] FIG. 7 is an embodiment of a
rope pulling mechanism of the presently disclosed device; and
[0024] FIG. 8 is a representation
of showing a rotational power source disengaged from the
presently disclosed device.
DETAILED DESCRIPTION
[0025] The presently disclosed embodiments provide devices
capable of lifting or pulling an object (e.g., a person) up or
along a tensioning member (e.g., a rope). More specifically, the
device is capable of mating to any location of any type of
tensioning member (e.g., various types, various lengths, various
diameters, etc.), and subsequently being interfaced with and
powered by a rotational power source (such a mechanical drill).
The use of such a rotational power source allows for a low cost,
simple to use, easy to carry device capable of lifting and/or
pulling heavy objects. In use, the device can be clipped to
either a climbing harness or Swiss seat, or can be attached to a
grounded object to act as a winch.
[0026] As will be discussed in detail below, the device can
provide a smooth, controlled, continuous pull while raising (or
lowering) an object (e.g., person). Further, the device can be
easy and intuitive to use by minimally trained or untrained
personnel. In order to perform various functions, the device can
apply its pulling force both at high force levels, for portable
winching applications, or at fast rates, for rapid vertical
ascents. As a safety feature, the device can include a safety
lock mechanism that prevents unwanted reverse motion of the rope
or cable. These and other aspects of the presently disclosed
device will be discussed in detail below.
[0027] FIG. 1 diagrammatically illustrates an exemplary
embodiment of the presently disclosed device 1. As shown, a
rotational power source (e.g., a power drill) 2 can interface
with the device 1. The rotational power source 2 can be a
portable device or a fixed device. Typically, the rotational
power source 2 can include a housing 2a and a drill output 2b.
In an exemplary embodiment, the rotational power source is a
mechanical drill. The ability to interface a low cost, every day
power drill 2 to the device 1 can provide significant cost
savings and simplicity to use of the device 1.
[0028] Depending on the rotational power source 2 used to power
the system, different pulling rates and load capabilities can be
achieved. Also, as will be discussed below, adjusting components
of the gearbox 3 can produce a desired pulling force. Exemplary
embodiments of the rotational power source 2 include a DeWalt
36V cordless hammer drill, p/n DC900KL, the DeWalt 36V cordless
rotary hammer, p/n DC232KL, or the DeWalt 36V cordless impact
wrench, p/n DC800KL, all as powered by 36V high-power Lithium
Ion battery packs, manufactured by A123 Systems, Inc, of
Watertown, Mass. The extremely high power to weight ratio (3000
W/kg) of these battery packs makes the DeWalt 36V cordless tools
allows for high loads and high pulling rates, and allows for
maximum versatility as a cordless power tool. In alternative
embodiments, the rotational power source 2 can include the 24V
Panasonic cordless rotary hammer, p/n EY6813NQKW, or other 28V,
24V, 18V, 14.4V or 12V cordless drill systems. Those skilled in
the art will appreciate that various other power drills are
within the spirit and scope of the present invention.
[0029] Various other types of rotational power sources 2 can be
utilized by the presently disclosed device. For example, the
rotational power source 2 can be a hand crank, an air wrench,
rotary saw, rotary hammer, or any device having a rotating
shaft. As will be appreciated by those skilled in the art,
various other rotational power sources are within the spirit and
scope of the present invention.
[0030] The output of the rotational power source 2 can be
coupled to a rotating drum 8 of the device 1. The output of the
rotational power source 2 is the rotating shaft of the rotating
power source 2. As such, coupling the output of the rotational
power source to the rotating drum provides a rotating force to
the rotating drum. FIG. 1 illustrates an exemplary embodiment
wherein the output is coupled to the rotating drum via a gear
box 3. As will be appreciated by those skilled in the art, the
gears of the gearbox 3 can be selected in order to provided a
desired force from the rotational power source 2 to the rotating
drums 8 (and ultimately to the tensioning member 6). The
rotational coupling between the rotational power source 2 and
the gearbox 3 can be accomplished via the chuck of the
rotational power source 2, or by various other means known in
the art. In an alternative embodiment, as shown in FIG. 2, the
rotational power source 2 can be coupled directly to the
rotating drum(s) 8 thereby eliminating the need for the gear box
3. Such coupling can be achieved via a drill chuck or as
otherwise known in the art. Those skilled in the art will
appreciate that the rotating drum(s) 8 of the device 1 can be
mated to the output of the rotational power source 2 in a
variety of manners and remain within the spirit and scope of the
present invention.
[0031] Next, FIG. 1 illustrates that the rotational power source
2 additionally includes a physical attachment 5 to the device 1.
The physical attachment 5 allows the rotational power source 2
to apply a directional torque to the rope pulling mechanism 4
with respect to the body of the rotational power source 2.
Further, the physical attachment 5 allows for added stability
and safety in order to ensure that the rotational power source 2
does not detach from the device while in use. As will be
apparent to those skilled in the art, the physical attachment 5
can include various forms. For example, the physical attachment
5 can include a direct attachment of a drill chuck (not shown)
of the rotational power source 2 to the device 1. Further, the
rotational power source 2 can include an extension (not shown)
which can be received in a "key-hole" element (not shown) of the
device 1 so as to lock the device 1 to the rotational power
source. In one example, clearly shown in FIGS. 3 and 4, the
physical attachment 5 can include a first circular element 5a
and a second circular element 5b capable of encircling portions
of the rotational power source 2 so as to maintain the
rotational power source 2 in communication with the device 1. As
will be apparent to those skilled in the art, the physical
attachment 5 of the device 1 to the rotational power source 2
can be accomplished in a wide variety of manners.
[0032] FIG. 1 further diagrams the tensioning member 6 being
acted upon by the device 1. The tensioning member 6 can include
any elongate resilient element capable of withstand a tension.
For example, the tensioning member 6 can include strings, ropes,
cables, threads, fibers, filaments, etc. Furthermore, the
tensioning member 6 can be of any diameter and/or length. Those
skilled in the art will appreciate that various examples of such
tensioning members 6 are within the spirit and scope of the
present invention.
[0033] As shown in FIGS. 1 and 2, the device 1 can include a
tensioning member guide mechanism 9 which allows for proper
positioning of the tensioning member 6 on the rotating drum(s).
Once properly positioned, a rope pulling mechanism 4 can be
activated by the rotational power source 2 to provide a
controlled and continuous force on the tensioning member 6
thereby allowing for a object attached to the tensioning member
6 or, alternatively, an object (e.g., a person) attached to the
device to be raised or pulled a desired distance. As will be
discussed below, an advantage of the presently disclosed device
is that the rope pulling mechanism 4 (including the guide
mechanism 9 and rotating drum(s) 8) can be mated to any location
of the tensioning member 6. As such, the present device 1
eliminates the need to thread an end of the tensioning member 6
into the device prior to use.
[0034] FIG. 3 illustrates an exemplary embodiment of the device
1 in use. As shown (see arrows), the tensioning element 6 can
enter the device 1 and be guided into a rope pulling mechanism
4. The rope pulling mechanism 4 comprises a tensioning member
guide mechanism 9 (as diagrammed in FIGS. 1 and 2) and at least
one rotating drum 8 wherein the guide member 9 can properly
position the tensioning member 6 onto the rotating drum(s).
Next, the device can include an attachment point 7 capable of
anchoring the device to a grounded body (e.g., a load when
pulling a load up the tensioning member, or a stable body when
acting as a portable winch). This attachment point 7 can allow
all tension imposed by the rope pulling mechanism 4 on the
tensioning member 6 to be relayed to the grounded body through
the device 1 itself, rather than through the body of the
rotational power source 2. In the embodiment of FIG. 3, the
attachment point 7 can be positioned collinear with the
tensioning element 6 and with the longitudinal axis of the
output of the rotational power source 2 so as to increase the
ease of use and ergonomics of the device 1. In such an
embodiment, when the tensioning member 6 is under tension, the
system, comprising the device 1 and rotational power source 2,
will be suspended in a neutrally stable orientation between the
distal end of the tensioning element 6 and the attachment point
7.
[0035] Looking in more detail at FIG. 3, the elongate tensioning
member 6 enters the device 1 horizontally, in accordance with
the primary longitudinal axis of the drive of the device 1, the
device comprising the rope pulling mechanism 4 and gearbox 3
(optional). The device can be further capable of receiving and
mating to the rotational power source 2. Once the tensioning
member is positioned and the rotational power source 2
activated, the tensioning member 6 can be pulled into the device
1 as indicated by the directional arrow. The tensioning member 6
exits the device 1 via the rope pulling mechanism 4 in a
vertical orientation. As indicated, the tensioning member 6 is
free of any additional imposed tension as the member 6 leaves
the device 1. Tension in the tensioning member 6 is relayed to
ground via the attachment point 7. In this embodiment, the
device 1 and rotational power source 2 can rest in a neutrally
stable orientation, suspended between the tensioning member 6
and the attachment point 7.
[0036] The device can additionally include various safety
features capable of preventing the device from unwanted backward
motion relative to the tensioning member 6. For example, the
gearbox 3 can include a worm gear. As will be appreciated by
those skilled in the art, if the gearbox 3 includes a worm gear
on the input side which is coupled to a spur or other gear as
part or all of the output side of the gearbox 3, the device 1
will not be back-drivable, meaning the rope pulling mechanism 4
will remain locked to all imposed tension in the system even if
the rotational power source 2 is removed. As will be discussed
in relation to FIG. 8, the capability to disengage the
rotational power source 2 from the device 1 while leaving the
device 1 under tension enables multiple devices 1 to be utilized
in tandem, all powered by moving the rotational power source 2
from device to device, increasing the tension in each respective
tensioning member 6 along the way.
[0037] As a further safety feature, equal facility for locking
the device 1 against back-tension may be enabled by placing a
frictional cam-lock 10 where the tensioning member 6 enters the
device 1. This cam-lock 10 utilizes self-help to increase
gripping force against the tensioning member 6 in response to
increased tension, thereby locking the tensioning member 6
against movement out of the device 1, and allowing movement into
the device 1 as depicted by the arrow. As will be appreciated by
those skilled in the art, the cam-lock 10 can also be placed at
different locations in the device 1, such as after the rope
pulling mechanism 4, with the same functionality being enabled.
Furthermore, those skilled in the art will appreciate that
various other safety/locking devices can be incorporated in the
device 1 while remaining within the spirit and scope of the
present invention.
[0038] FIG. 4 depicts an alternative embodiment of the device
with a rearranged component configuration. As shown, the
tensioning member 6 can enter the device 1 vertically, in
accordance with the directional arrow. The tensioning member 6
then can exit the rope pulling mechanism 4 and device 1
vertically and without tension, in accordance with the second
directional arrow. Tensile force imposed by the rope pulling
mechanism 4 on the tensioning member 6 can be relayed through
the device 1 to the attachment point 7' which can provide an
anchor to a grounded body, and which may be oriented collinear
with the taut side of the tensioning element 6, to allow the
device 1 and rotational power source 2 to rest in a more usable
neutral orientation during use.
[0039] As described above, the rope pulling mechanism 4 of the
device 1 is capable of engaging and pulling the tensioning
member 6 through the device. Various exemplary embodiments of
the rope pulling mechanism 4 are described in U.S. Provisional
Patent Application 60/717,343, filed September 2005, entitled
"Powered Rope Ascender and Portable Rope Pulling Device," and
U.S. patent application Ser. No. 11/376,721, filed Mar. 15,
2006, entitled "Powered Rope Ascender and Portable Rope Pulling
Device," which are expressly incorporated herein by reference.
[0040] FIG. 5 is a view of the distal end of the device 1
utilizing an exemplary embodiment of the rope pulling mechanism
as disclosed in the above-identified incorporated applications.
As shown, the rope pulling mechanism includes a rotating drum 8
and a guide mechanism 9. The rotating drum 8 includes a
longitudinal axis and a circumference wherein the longitudinal
axis is positioned substantially parallel to a longitudinal axis
of the tensioning member thereby allowing the drum 8 to act, in
general, as a capstan. Further, the guide member 9 is configured
to receive the tensioning member 6, and further configured to
guide the tensioning member 6 onto, around at least a portion of
the circumference of, and off of the rotating drum 8.
[0041] FIGS. 6A and 6B show views of an exemplary embodiment of
the rotating drum. In this embodiment, the operation of a rope
pulling device 1 can be aided by designing the surface of the
rotating drum 8 to have anisotropic friction properties. In
particular, the drum can be designed to have a high friction
coefficient in a direction substantially about its circumference
and a lower friction coefficient in a substantially longitudinal
direction. In an exemplary embodiment, the rotating drum is a
cylinder; however, as will be apparent to those skilled in the
art, various other shapes can be used and are meant to be
encompassed by the word "drum". As shown in FIG. 6A, the surface
of the drum 8 can include longitudinal splines to create this
anisotropic friction effect. In this embodiment, a cylinder,
preferably constructed of aluminum or another lightweight metal
or material, is extruded to include the illustrated longitudinal
splines. More specifically, as clearly shown in FIG. 6B, the
rotating drum 8 can include longitudinal shaped-shaped splines
20 and a hole for a shaft with a keyway cutout 24. Forming the
longitudinal splines as shaped features angled into the
direction of motion of the rotating drum 8 further enhances the
friction between the rope and the drum. Additionally, various
weight-reducing holes 22 can also be utilized to minimize weight
of the entire device.
[0042] FIG. 7 shows an alternative embodiment wherein the rope
pulling mechanism 4 can include a plurality of rotating drums 8,
generally acting in the manner of pulleys, which interact with
the tensioning member 6 to pull the tensioning member 6 through
the device 1. As shown, the longitudinal axis of the rotating
drums 8 are positioned substantially perpendicular to the
longitudinal axis of the tensioning member 6. In this
embodiment, the output of the gearbox 3 is coupled rotationally
to at least one of the rotating drums 8. When an initial tension
is imposed on the tensioning member 6, either by the working
load or by the rope pulling mechanism 4, a partial or full wrap
of the tensioning member 6 around each drum 8 provides an
amplified tensile force due to the capstan effect, and thereby
increases the frictional force between the rotating drums 8 and
the tensioning member 6. Alternatively, the output of the drill
2 can be rotationally coupled directly to one or more of the
rotating drums 8 without going through an additional gearbox 3.
[0043] As will be appreciated by those skilled in the art, the
various embodiments of the device can allow for a variety of
uses. For example, in one embodiment, the object can be attached
to the distal end of the tensioning element 6 with the
attachment point 7 of the device 1 anchored to a grounded point,
thus pulling the object toward the stationary device 1. In an
alternative embodiment, the object can be connected to the
attachment point 7 of the device 1, with the distal end of the
tensioning element 6 being fixed to a grounded point, in
operation thereby pulling the device 1 and its load along the
tensioning element 6 toward the fixed distal end. As such, the
device 1 and rotational power source 2 can be suspended in a
stable orientation between the distal end of the tensioning
element 6 and the attachment point 7, regardless of the relative
orientation of those two points. This allows loads to be pulled
horizontally, vertically, or at any angle in between, with the
weight of the rotational power source 2 imposing minimal
off-axis moments to the tensioning element 6, and thereby
positioning the device 1 and rotational power source 2 suspended
in an orientation of higher ergonomic usability to the operator.
[0044] As briefly mentioned above, while in use, the device 1
can be disengaged from the rotational power source 2 while
keeping a desired tension on the tensioning member 6. FIG. 8
shows such an embodiment wherein the tension between the
tensioning member 6 and the ground 11 can be maintained due to
the restriction of backward motion of the tensioning member 6 by
either a cam-lock 10 or by a non-backdrivable gearbox 3 (each
discussed above). The functionality enabled by this
configuration is such that multiple devices 1 can be used in
tandem with the same rotational power source 2 moving between
devices 1 to increase tension sequentially in multiple
tensioning members 6, such as in tent guys, or truck tie-downs.
[0045] A person of ordinary skill in the art will recognize that
the configurations described above are not the only
configurations that can employ the principles of the invention.
The system and method described above, utilizing a rope pulling
mechanism comprising a rotating drum and a rope guide mechanism,
powered by a rotational power source such as a motorized drill
or other rotational device, can be practically employed in
various other configurations. As such, any configuration or
placement of all the parts, rotational power source, gearbox,
and rotating drum/guide assembly with relation to one another
could be deployed by a person of ordinary skill in keeping with
the principles of the invention. Additionally, various
components can be added or subtracted to the device and/or
system while remaining within the spirit and scope of the
present invention.
[0046] The lifting and pulling of heavy objects is a
wide-ranging task inherent in many endeavors, commercial,
domestic, military, and recreational. The presently disclosed
device, a portable rope pulling and climbing device, can solve
many problems associated with using current lifting and pulling
technology, including but not limited to: accommodating multiple
types and diameters of flexible tensioning members, being able
to attach to the flexible tensioning member without threading a
free end through the device, and being capable of providing a
smooth continuous pull. Furthermore, the presently disclosed
embodiments provide a device which itself can travel up or along
a rope, provide a device which is easy and intuitive to use,
provide a device which can let out or descend a taut flexible
tensioning member at a controlled rate with a range of loads,
and further, provide a device and method that is usable in and
useful for recreation, industry, emergency, rescue,
manufacturing, military, and other applications.
[0047] A person of ordinary skill in the art will appreciate
further features and advantages of the presently disclosed
device based on the above-described embodiments. For example,
specific features from any of the embodiments described above as
well as those known in the art can be incorporated into the
presently disclosed embodiments in a variety of combinations and
subcombinations. Accordingly, the presently disclosed
embodiments are not to be limited by what has been particularly
shown and described. Any publications and references cited
herein are expressly incorporated herein by reference in their
entirety.
POWERED ROPE
ASCENDER AND PORTABLE ROPE PULLING DEVICE
US2008017838
A device for pulling an elongate member includes a powered
rotational motor having an output and a rotating drum connected
to the output of said rotational motor where the rotating drum
has a longitudinal axis and a circumference. The device further
includes a guide mechanism for guiding the resilient elongate
element onto, around at least a portion of the circumference of,
and off of, the rotating drum. When the powered rotational motor
turns the rotating drum, the rotating drum thereby continuously
pulls the resilient elongate element through the device
FIELD OF INVENTION
[0002] This invention relates to devices for moving an object by
pulling on an elongate element to which the object is attached.
More particularly, the invention relates to a device that can
lift or pull heavy objects by pulling on a rope or cable.
BACKGROUND OF THE INVENTION
[0003] Winches are typically used to lift heavy loads or pull
loads across horizontal obstacles. Winches are either
motor-driven or hand powered and utilize a drum around which a
wire rope (i.e. metal cable) or chain is wound. Manually lifting
or pulling heavy objects is not a viable option due to the
strength required to lift or pull such objects. Often, fatigue
and injury result from manually lifting or pulling such objects.
This is why winches are used; they possess massive pulling and
towing capabilities, and can serve well for handling heavy
objects.
[0004] However, winches are limited in their usefulness for
several reasons. First, the cable or rope is fixed permanently
to the drum, which limits the maximum pull distance and
restricts the towing medium to only that rope or cable. Second,
the winch must be fixed to a solid structure to be used,
limiting its placement and usability. Third, controlled release
of tension is not a capability of many winches, further limiting
usability.
[0005] Current technology in rope ascenders used by people for
vertical climbing consists of passive rope ascenders which must
be used in pairs. These rope ascenders function as a one-way
rope clamp, to be used in pairs. By alternating which ascender
bears the load and which ascender advances, upward motion along
a rope can be created.
[0006] Passive ascenders such as these are severely limited in
their usefulness for several reasons. First, they rely on the
strength of the user for upward mobility. Thus, passive
ascenders are not useful in rescue situations where an injured
person needs to move up a rope. Second, the need to grip one
ascender with each hand limits multi-tasking during an ascent
because both hands are in use. Third, the rate and extent of an
ascent are limited to the capabilities of the user. Fourth, the
diamond grit used to grip the rope is often too abrasive,
destroying climbing ropes for future use. Fifth, the type of
rope to be used is limited by what the ascenders' one-way locks
can interact properly with.
[0007] Raising heavy loads upward via cable is accomplished by
winches pulling from above the load, or by a device such as a
hydraulic lift that pushes from below. Passive rope ascenders
are useless for moving a dead weight load upward along a rope.
U.S. Pat. No. 6,488,267 to Goldberg et al., entitled "Apparatus
for Lifting or Pulling a Load" is an apparatus which uses two
passive ascenders along a rope with a pneumatic piston replacing
the power a human would normally provide. Thus, this powered
device is limited in its usefulness by the same factors
mentioned above. In addition, the lifting capacity and rate of
ascent are is limited by the power source that fuels the
pneumatic piston.
[0008] A further drawback of this design is that at any
reasonable rate the load will experience a significant jerking
motion in the upward direction during an ascent. Therefore,
fragile loads will be at risk if this device is used.
[0009] It is therefore an object of the present invention to
provide an apparatus for lifting or pulling heavy loads which
solves one or more of the problems associated with the
conventional methods and techniques described above.
[0010] It is another object of the present invention to provide
an apparatus for lifting or pulling heavy loads which can be
manufactured at reasonable costs.
[0011] It would also be desirable as well to be able to attach
any such rope pulling device to a rope at any point along that
rope without having to thread an end of the rope or cable
through the device. This would increase the usability of such a
device considerably over other rope pulling and climbing
devices, allowing for instance a user to attach himself for
ascent at a second story window past which a rope hangs.
[0012] Other objects and advantages of the present invention
will be apparent to one of ordinary skill in the art in light of
the ensuing description of the present invention. One or more of
these objectives may include:
(a) to provide a line pulling device that can handle a range of
rope types, cables, and diameters;
(b) to provide a device which does not require an end of the
rope or cable to be fixed to the device;
(c) to provide a device which provides a smooth, controlled,
continuous pull;
(d) to provide a device which itself is capable of traveling
upward along a rope or cable smoothly and continuously to raise
a load or a person;
(e) to provide a device which is easy and intuitive to use by
minimally trained or untrained personnel;
(f) to provide a device which can let out or descend a taut rope
or cable at a controlled rate with a range of loads;
(g) to provide a device which can apply its pulling force both
at high force levels, for portable winching applications, and at
fast rates, for rapid vertical ascents;
(h) to provide a device with a safety lock mechanism that
prevents unwanted reverse motion of the rope or cable;
(i) to provide a device that can attach to a rope or cable at
any point without having to thread an end of the rope or cable
through the device;
j) to provide a device that is not limited in its source of
power to any particular type of rotational motor; and
(k) to provide a device that is usable in and useful for
recreation, industry, emergency, rescue, manufacturing,
military, and any other application relating to or utilizing
rope, cable, string, or fiber tension.
[0024] Still further objects and advantages are to provide a
rope or cable pulling device that is as easy to use as a
cordless power drill, that can be used in any orientation, that
can be easily clipped to either a climbing harness or Swiss
seat, that can be just as easily attached to a grounded object
to act as a winch, that is powered by a portable rotational
motor, and that is lightweight easy to manufacture.
SUMMARY OF THE INVENTION
[0025] The invention provides a rope or cable pulling device
that preferably accomplishes one or more of the objects of the
invention or solves at least one of the problems described
above.
[0026] In a first aspect, a device of the invention includes a
powered rotational motor having an output and a rotating drum
connected to the output of said rotational motor where the
rotating drum has a longitudinal axis and a circumference. The
device further includes a guide mechanism for guiding the
resilient elongate element onto, around at least a portion of
the circumference of, and off of the rotating drum. When the
powered rotational motor turns the rotating drum, the rotating
drum thereby continuously pulls the resilient elongate element
through the device.
[0027] A device of the invention can conveniently be configured
as a portable hand-held device, and in particular, can be
configured as a portable rope ascender. Further aspects of the
invention will become clear from the detailed description below,
and in particular, from the attached claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 provides a
diagrammatic view of a device of the invention;
[0029] FIG. 2 shows an isometric
view of an embodiment of the invention, showing a motor,
batteries, handle, rotating drum, guiding rollers, safety
clamp, tensioning roller and clip-in attachment point;
[0030] FIG. 3 shows a front view of
the device of FIG. 2;
[0031] FIG. 4 shows a side view of
the device of FIG. 2;
[0032] FIG. 5 shows a close-up
profile and isometric view of the rotating drum of the device
of FIG. 2;
[0033] FIG. 6 shows an isometric
view of an alternative embodiment of the invention;
[0034] FIG. 7 shows a front view of
the embodiment of FIG. 6;
[0035] FIG. 8 shows a side view of
the embodiment of FIG. 6;
[0036] FIG. 9 illustrates a further
embodiment of the invention;
[0037] FIG. 10 shows isometric view
of the embodiment of FIG. 9; and
[0038] FIG. 11 shows a side view of
the embodiment of FIG. 9.
DETAILED DESCRIPTION
[0039] Referring now to FIG. 1, a device 100 of the invention
for pulling a resilient elongate element such as a cable or a
rope 114 is illustrated diagrammatically. The device includes a
rotational motor 102 from which the pulling motion of the device
is derived. A number of different types of motors, such as two
or four stroke internal combustion engines, or ac or dc powered
electric motors, could be employed to provide the rotational
motion desired for pulling the rope or cable. A motor power
source 104 can also be included that is appropriate to the
rotational motor used, such as gasoline or other petroleum
products, a fuel cell, or electrical energy supplied in ac (such
as from a power outlet in a typical building) or dc (such as
from a battery) form. In one preferred embodiment, the
rotational motor is a dc electric motor and the motor power
source is one or more rechargeable lithium ion batteries.
[0040] The rotational motor can also have speed control 106
and/or a gearbox 108 associated with it to control the speed and
torque applied by the rotational motor to the task of pulling a
rope. These elements can be integrated into a single,
controllable, motor module, be provided as separate modules, or
be provided in some combination thereof. In one embodiment,
speed control elements can be provided integrally with a dc
rotational motor, while a separate, modular gearbox is provided
so that the gearing, and thus the speed and torque
characteristics of the rope pulling device, can be altered as
desired by swapping the gears.
[0041] A rotating drum 110 is connected to the rotational motor,
either directly or through a gearbox (if one is present). It is
the rotating drum, generally in the manner of a capstan, that
applies the pulling force to the rope that is pulled through the
device 116. In a preferred embodiment of the invention, the
rotating drum provides anisotropic friction gripping 112 of the
rope. In particular, in a preferred embodiment, the surface of
the rotating drum has been treated so that large friction forces
are created in the general direction of the pulling of the rope
(substantially around the circumference of the drum), and
smaller friction forces are created longitudinally along the
drum so that the rope can slide along the length of the drum
with relative ease.
[0042] In the alternative embodiment of the rope interaction
assembly depicted in FIGS. 9, 10 and 11, the rotating drum is
split into sections. These sections rotate between stationary
sections which contain guide rollers that move the rope from one
wrap to the next. This embodiment also makes use of the splined
drum to exploit the anisotropic friction when advancing the rope
from each wrap to the next.
[0043] A rope or cable is also referenced in FIG. 1. The device
of the present invention is intended to be able to be able to
pull any elongate resilient element that can withstand a
tension. Cables and ropes are the most common of these, but the
invention is not meant to be limited by the reference to ropes
or cables.
[0044] A preferred embodiment of a rope pulling device 100 of
the invention is shown in FIGS. 2 (Isometric view), 3 (front
view) and 4 (side view). In this embodiment, rotational motor 4
applies rotational power to rotating drum 8 via gearbox 6.
Batteries 3 apply necessary power to motor 4. A rope handling
mechanism guides a rope to and from the rotating drum. In
particular, rope 21 enters through rope guide 1 and continues
through safety clamp 2. The rope is further guided tangentially
onto the rotating drum 8 by a pulley 7 and rotating guide 15.
Once the rope is on the drum 8 it is guided around the drum 8 by
the rollers 9 (and non-labeled adjacent rollers). On the last
turn, the rope passes between the tensioning roller 10 and the
drum 8. A user attaches to the device, such as by a tether, at
attachment point 11.
[0045] As noted above, the operation of a rope pulling device of
the invention can be aided by designing the surface of the
rotating drum 8 to have anisotropic friction properties. In
particular, the drum can be designed to have a high friction
coefficient in a direction substantially about its circumference
and a lower friction coefficient in a substantially longitudinal
direction. In the embodiment illustrated in FIGS. 2 through 4,
the surface of the drum is provided with longitudinal splines to
create this anisotropic friction effect. A preferred embodiment
of such a splined drum is shown in FIG. 5. In this embodiment, a
cylinder, preferably constructed of aluminum or another
lightweight metal or material, is extruded to include the
illustrated longitudinal splines. More specifically, the
rotating drum 8 embodiment of FIG. 5 can include longitudinal
shaped-shaped splines 12 and a hole for a shaft with a keyway
cutout 14. Forming the longitudinal splines as shaped features
angled into the direction of motion of the rotating drum 8
further enhances the friction between the rope and the drum. A
person skilled in the art will recognize that the drum of FIG. 5
is one preferred embodiment and that other features or methods
of manufacture can be used to create the desired anisotropic
friction effect.
[0046] Weight-reducing holes 13 can also be utilized to minimize
weight of the entire device.
[0047] Returning now to FIGS. 2-4 to further describe the
features and operation of this embodiment of a rope pulling
device of the invention, rope 21 enters the device through the
clip-in rope guide 1. As illustrated, a solid loop is provided,
however, the rope guide 1 is preferably a carabiner-type clip
into which the rope is pushed, rather than having to thread the
rope through by its end. The rope then passes through the safety
clamp 2, which allows rope to only move through the device in
the tensioning direction.
[0048] In the case that rope is pulled backward through the
device by any means, the safety clamp 2 grips the rope and
pinches it against the adjacent surface. The handle on the
safety clamp 2 allows a user to manually override that safety
mechanism, by releasing the self-help imposed clamping force
which the clamp applies to the rope against the body of the
device. The safety clamp 2 is simply one as used in sailing and
rock climbing, and uses directionally gripping surfaces along a
continuously increasing radius to apply a stop-clamping force
proportional to the rope tension which squeezes the rope against
its guide.
[0049] After passing through the safety clamp, the rope is
wrapped past the pulley 7 which guides the rope tangentially to
the drum. The set of rollers 9 folds away from the drum,
allowing the user to wrap the rope the designated number of
times around the drum (in this case 5). After having wrapped the
rope to the specified spacing, the rollers 9 fold back against
the drum and are locked in place. The tensioning roller 15
squeezes the last turn of the rope against the splines in order
to apply tension to the free end of the rope. Since the capstan
effect occurs as:
T1=T2e<([mu][theta])> [1]
Where T2 is the tension off the free end (exiting tensioning
roller 15), T1 is the tension in the rope as it enters through
the rope guide 1, [mu] is the frictional coefficient between the
rope and the rotating drum 8, and [theta] is the amount the rope
is wrapped around the rotating drum 8 in radians. An initial
tension in the free end exiting roller 10 is necessary to
achieve any kind of circumferential gripping of the rope around
the capstan, i.e. T2 cannot be 0. By squeezing the rope against
the capstan splines 1 with the tensioning roller 10, T2 tension
is created by the last turn as it makes a no-slip condition
which is reflected back through each turn to achieve a large
tension at the first turn, T1.
[0050] Since the rope guide 1 has a clip-in and the rollers 9
and tensioner 10 attached to roller support 18 fold away from
the drum via pivot 17 (a person of skill in the art will note
that the roller support is not limited to pivotal movement-any
sliding motion, rotation, or combination thereof can suffice to
move roller support 18 away), loading the rope into the device
does not require stringing a free end through the device. The
device can thus accommodate any length of rope and can join or
detach from the rope at any point. This is a significant
advantage over standard winch systems which must only use the
length of rope or cable that is already attached, and which must
be confined to one particular position and orientation for
operation.
[0051] A person skilled in the art will also note that the
rollers 9 can be held from within the rotating drum 8,
positioned and held by stationary cylindrical segments fixtured
to the gearbox 6 from solid supports located within rotating
drum 8. Rotating drum 8 could thus be segmented with rollers 9
positioned in between segments of drum 8 at the same interval as
in FIGS. 2-4. This circumvents the need for an external roller
support 18, allowing for a elongate tensioning member to be
wrapped around drum 8 and guided by rollers 9 roller support 18
in the way. An embodiment that utilizes this configuration is
depicted in FIGS. 10 (isometric view), 11 (side view), and 12
(side view including rope illustration).
[0052] Longitudinal splines 12 on drum 8 improve the operation
of the illustrated embodiment. These features create and use the
anisotropic friction behavior along the drum which allows a wrap
of a rope or cable to grip the drum circumferentially while
moving readily along that drum axially. Exemplary splines 12 are
jagged in the forward rotational direction in FIG. 5 where the
illustrated drum is intended to apply force in a
counterclockwise direction. The additional grip provided by the
exemplary drum 8 maximizes the capstan effect in equation [1]
created by a tensioned cable wrapped around a drum,
significantly increasing the circumferential gripping, while
still allowing axial motion of the wrap along the drum. This,
combined with the axial force applied by rollers 9, overcomes a
significant problem faced by others attempting to use a turning
capstan (cylindrical drum) to advance a rope while maintaining a
free end.
[0053] In a standard winch, rope is progressively built up on
the rotating drum. If one were to attempt to maintain a free end
of the rope and have the rope travel through the winch and exit
continuously, a problem would arise. First, as shown by equation
[1], without tension T2 on the free end, no pulling force can be
applied to the rope. Additionally, since the rope grips around
the drum circumferentially while under tension, even if T2 is
artificially created, the rope will wrap back on itself because
of spiraling of the wraps. Due to the uneven tension and uneven
placement of that tension along the drum, an axial restoring
force appears which pulls the taut first wrap (T1) toward the
loose wrap at tensioner 10. When the rope wraps back on itself,
it binds, preventing any further pulling.
[0054] In the illustrated device, the rollers 9 positioned along
the capstan provide a restoring force in the axial direction to
keep the wraps from backing up and binding. The rotating guide
15 applies back-force to the first (and tightest) wrap where
tension is T1 (and therefore the most force is necessary to move
that wrap down the drum). The splines 12 facilitate the use of
the rollers 9 and rotational guide 15 by allowing
circumferential gripping and torque application in the correct
rotational direction, while allowing the tensioned wraps to be
moved axially along the drum as they enter and exit the device.
While this particular embodiment works well as illustrated, any
sort of material or feature (such as other edge profiles,
re-cycling sliders, pivots, and rollers) providing similar
anisotropic friction conditions could be used as effectively.
[0055] An additional embodiment of the splined drum is one that
changes diameter along its longitudinal axis in order to aid
axial movement of wraps along its body. This could aid in the
movement of the high-tension wraps as pushed by the rollers 9.
[0056] This illustrated embodiment of the rope pulling device
enables new capabilities in pulling ropes and cables at high
forces and speeds. The embodiment described utilizes a
high-power DC electric motor 4, as built by Magmotor Corporation
of Worcester, Mass. (part number S28-BP400X) which possesses an
extremely high power-to weight ratio (over 8.6 HP developed in a
motor weighing 7 lbs). The batteries 3 utilized are 24V, 3AH
Panasonic EY9210 B Ni-MH rechargeable batteries. The device
incorporates a pulse-width modulating speed control, adjusted by
squeezing the trigger 16, that proportionally changes the speed
of the motor. This embodiment is designed to lift loads up to
250 lbs up a rope at a rate of 7 ft/sec. Simple reconfigurations
of the applied voltage and gear ratio can customize the
performance to lift at either higher rates and lower loads, or
vice-versa.
[0057] Any embodiment of the design as described above can be
used to apply continuous pulling force to flexible tensioning
members (strings, ropes, cables, threads, fibers, filaments,
etc.) of unlimited length. Also since the design allows for
attachment to such a flexible tensioning member without the need
of a free end, significant versatility is added. The design
allows for a full range of flexible tensioning members to be
utilized for a given rotating drum 8 diameter, further enhancing
the usability of such a pulling device.
[0058] A further embodiment of the invention is illustrated in
FIGS. 6, 7 and 8. This embodiment operates on a number of the
same simple principles as the embodiment of FIGS. 2 though 4,
but relies on slightly different implementations of those
principles. Rope enters the device by wrapping around the safety
cam 2. This cam is a modified version of a Petzl Grigri rope
belayer/descender, and uses a self-help pinching mechanism to
prevent unwanted backward motion of a rope or cable. The handle
allows the user to manually override that safety clamp in order
to control a descent or back-driving of the rope through the
device.
[0059] After the safety cam 2, the rope is wrapped around the
pulleys 7 to be guided tangentially onto the rotating drum 8
within the spiral of the helix guide 19. The rope is wrapped
through the turns of the helix guide 19, and the tensioning
roller housing 20 is opened away from drum 8 to accept the rope
as it goes through. Then the tensioning roller housing 20 is
closed and clamped tight to the base of the helix guide S, which
applies pressure from the tensioning roller 10 to the rope,
clamping the rope against the tensioning drum 22.
[0060] Operation of this embodiment by a user is identical to
that of the embodiment described above; the trigger 16 is
squeezed, controlling the speed of the motor 4, which applies
torque to the rotating drum 8 through the gearbox 6. The rope is
gripped around the rotating drum 8 by the tension T1 on the rope
entering the device, as guided by the safety cam 2 and pulleys
7, and according to equation [1]. The tension T2 which is
necessary to make the device work is applied via the tensioning
roller 10, as it is clamped by the tensioning roller housing 20.
However, unlike the previous embodiments, instead of creating a
no-slip condition to achieve T2, a dynamic friction is utilized
to tug on the rope, creating the needed tension in the free end.
[0061] This is accomplished by the tensioning drum 22 having a
larger diameter than the rotating drum 8. Since both are
attached to the same drive shaft out of the gearbox 6, they have
the same rotational velocity. But because of the bigger diameter
on the tensioning part of the drum 22, the surface velocity is
greater. Because more turns (and the higher tension turns) in
the rope are along the original diameter on the drum 8, rope is
fed at the rotational velocity times the diameter of drum 8.
Since the tensioning drum 22 has a greater diameter, it
constantly slips against the surface of the rope. The normal
force of the rope against drum 22 is increased by the tensioning
roller, allowing for a greater pulling force to be created by
drum 22. Thus, the dynamic friction against the last turn of the
rope creates a constant T2 which is the basis for the operation
of the device, as per equation [1].
[0062] The problem of the rope wrapping back on itself is solved
with the helix guide 19, which guides the rope onto and off of
the rotating drum 8. Splines may not be used in this version,
since it is more useful for smaller loads and the anisotropic
friction is not a required feature. The helix guide 19
continually pushes the wraps axially down the drum 8, since the
helix 19 is stationary and the rope must move. It provides the
same function as the rollers 9 in the preferred embodiment,
however with more friction. The helix 19 also still accommodates
utilization of the rope or cable at any point, and the design
for this embodiment does not require a free end of the rope to
be strung through.
[0063] A user attaches to the device (or attaches an object to
the device, or the device to ground) via the attachment point 11
as in the previous embodiment. The ergonomic handle 5 with
speed-controlling trigger 16 provide easy use similar to that of
a cordless drill. The batteries and motor can be the same as in
the previous embodiment. This embodiment of the design, however,
may be less expensive to manufacture and more useful in
applications where continuous pulling of a flexible tensioning
member is necessary under lower loads (e.g., less than 250 lbs).
[0064] An alternative embodiment depicted in FIGS. 9 (isometric
view), 10 (side view) and 11 (side view including rope
illustration). As previously noted with respect to FIGS. 2
through 4, the guide rollers 9 are mounted to a non-rotating
section of the device in order to guide the wraps of the rope
down the rotating drum 8. In that embodiment, the rollers 9 are
mounted to the roller support 18. However, this embodiment
requires the support 18 to be moved away from the rotating drum
8 in order to wrap the rope onto the capstan.
[0065] An alternative is to mount the guide rollers 9 to
stationary mounts 25 placed between rotating drum sections 8 as
depicted in FIGS. 10, 11 and 12. These stationary mounts are
held stiff with respect to the device via the rotational
constraints 24. The contour of the rotational constraints 24
allows for the rope to be wrapped around the capstan in a spiral
fashion, with the wraps guided from one to the next by the guide
rollers 9. The rollers 9 in this embodiment are held in place by
the guide roller bolts 27. The axis of the bolts is oriented
radially inward to the rotational axis of the rotating drum 8. A
person skilled in the art will note that the orientation of the
guide rollers 9 with respect to the circumference and rotational
axis of the rotating drum sections 8 is not limited to that of
this particular example-other roller orientations will still
accomplish the task of moving the rope through each wrap.
[0066] The mounting of the entire capstan assembly embodiment is
such that it replaces everything below the gearbox 6 in either
of the two aforementioned embodiments. The capstan assembly base
23 mounts to the gearbox 6, with a drive shaft extending through
both, all the way to the capstan end plate 28. The rotating drum
sections 8 are locked to the drive shaft, and radial bearings
are inside each stationary section 25, the capstan assembly base
23, and the capstan end plate 28.
[0067] The rope is guided onto the first rotating section 8 by
the same guide pulley 7, and is then wrapped in a helical
fashion around the assembly, going through each gap between the
guide rollers 9. Finally, it is slipped between the tensioning
roller 10 and the final stationary section 25, and the tensioner
lever 26 is closed. The tensioning roller 10 is pressed against
the rope, and is held in place by a latch that keeps the
tensioner lever 26 tight against the capstan end plate 28.
[0068] After the tensioning roller 10 is closed and force is
thus applied to the last wrap of the rope on the capstan, the
devices is ready to be used. Using this embodiment, the rope can
be fully engaged and disengaged from the device without
threading an end through the mechanism.
[0069] A smaller version of this device could use the same sort
of helical guide 19 and dynamic friction tensioner 10 to advance
unlimited lengths of any sort of tensioning material, and could
be particularly useful in the manufacture of cord materials such
as steel cable, rope, thread, yarn, dental floss, and electrical
conductors.
[0070] A person of ordinary skill in the art will recognize that
the configurations described in FIGS. 1-11are not the only
configurations that can employ the principles of the invention.
The system and method described above, utilizing circumferential
gripping of a rotating drum while pulling with a free end of a
tensioning member can be practically employed in other
configurations. While certain features and aspects of the
illustrated embodiments provide significant advantages in
achieving one or more of the objects of the invention and/or
solving one or more of the problems noted in conventional
devices, any configuration or placement of all the parts, motor,
battery, gearbox, and rotating drum/guide assembly with relation
to one another could be deployed by a person of ordinary skill
in keeping with the principles of the invention.
[0071] The lifting and pulling of heavy objects is a
wide-ranging task inherent in many endeavors, commercial,
domestic, military, and recreational. Current technology for
portable lifting and pulling devices is limited to passive rope
ascenders, as in climbers'equipment, and winches and
come-alongs, which all have severe limitations for the power
sources, rate of pulling, and types of tensioning members they
can utilize.
[0072] The present invention, a portable rope pulling and
climbing device, can solve many problems associated with using
current lifting and pulling technology, including but not
limited to: accommodating multiple types and diameters of
flexible tensioning members, being able to attach to the
flexible tensioning member without threading a free end through
the device, providing a smooth continuous pull, providing a
device which itself can travel up or along a rope, to provide a
device which is easy and intuitive to use, to provide a device
which can let out or descend a taut flexible tensioning member
at a controlled rate with a range of loads, and to provide a
device and method that is usable in and useful for recreation,
industry, emergency, rescue, manufacturing, military, and other
applications.
[0073] A person of ordinary skill in the art will appreciate
further features and advantages of the invention based on the
above-described embodiments. For example, specific features from
any of the embodiments described above as well as in the
Appendix below may be incorporated into devices or methods of
the invention in a variety of combinations and subcombinations,
as well as features referred to in the claims below which may be
implemented by means described herein. Accordingly, the
invention is not to be limited by what has been particularly
shown and described, except as indicated by the appended claims
or those ultimately provided. Any publications and references
cited herein are expressly incorporated herein by reference in
their entirety.
MULTIPLE LINE
POWERED ROPE ASCENDER AND PORTABLE HOIST
WO2008060450
A multiple-rope or multiple-cable pulling device is provided for
positioning a load. The device can include an electronic
controller that interprets a user's input from an interface such
as a trigger or a joystick, and activates electronically
controlled motors that drive one or more rope pulling
mechanisms, such as winches. When the winches pull in or pay out
cable in accordance with the controller's demand, the load is
moved along the desired trajectory as specified by the user
through the device interface.
FIELD OF INVENTION
This invention relates to devices for moving an object by
pulling on two or more tensile elongate elements to which the
object is attached. More particularly, the invention relates to
a device that attaches to and preferentially pulls on multiple
ropes or cables for positioning a load in multidimensional
workspaces.
BACKGROUND OF THE INVENTION
Existing methods of gaining access to large vertical faces such
as the sides of buildings or rock faces are limited to either
minimal 1 -dimensional access capabilities, such as single rope
rappelling systems for climbers, rescuers, or window washers, or
large, bulky installations such as cranes, scaffolding, or
external elevators.
Window washing systems that utilize standard rappelling
equipment are limited in their access to the side of a building
by the single line from which the operator hangs. In order to
move laterally for any significant distance, the operator must
descend to the bottom of the building, return to the rooftop and
reposition his line, and then re-descend to the desired
position. Similarly, climbers and rescue personnel who wish to
access a specific point on a rock face or other vertical site
must descend from directly above the desired position. When
access to the ideal starting position above the target is not
available, the operator may face extreme difficulty in accessing
the desired position and must resort to additional support
personnel or equipment to provide lateral movement capabilities.
For large buildings where it may be appropriate to do so,
scaffolding systems can be set up, either stationary or movable,
to provide 2 dimensional access to the entire building face
where needed. However, any system capable of providing such
access requires significant cost, space, setup time, and
operation time. Alternatively, ground lift systems such as
cranes or vertical hoists can be used, but face similar
limitations of cost, space, and access provided. A device that
can be quickly, cheaply, and easily deployed which can give an
operator precise, safe, and reliable access to vertical
workspaces, such as sides of buildings and rock faces, would be
of significant benefit to a variety of users. Rescue personnel
could descend from a high point adjacent to the victim, instead
of directly from above, and approach them laterally without
disturbing loose and potentially dangerous objects, overhead
obstacles, or the victim. Window washers could access an entire
building face without needing to reset overhead lines, and
construction workers could deliver equipment and personnel
quickly and easily to many points on a high worksite. Additional
functionality could be found in the entertainment industry,
running high wires to pull actors into the air and manipulate
their position in 2 dimensions remotely without the need for
overhead rolling track carrier systems, as well as other setups
where such carrier systems are needed. Other uses include
installing, positioning and uninstalling overhead speaker and
light systems at concerts and sporting events, as well as
positioning camera systems.
Similarly, positioning loads in 3 dimensional spaces is commonly
accomplished by large, bulky systems such as overhead gantries
or cranes that are not designed for portability or low cost. The
ability to use a single low-cost device to accurately position
loads, including workers, could be significantly advantageous
for situations where a load manipulation system must be modular,
quickly deployable, or able to fit and maneuver in confined
spaces. Still another application where a 2 or 3 dimensional
load positioning system would have further advantages over
existing load positioning technology such as conventional hoists
with swinging booms is in a hospital, where heavy patients must
be maneuvered from stretchers to operating tables. Conventional
hoists with swinging arms are impractical because the trajectory
of the boom and the patient require that the entire area be
clear to avoid collisions with equipment. It is therefore an
object of the present invention to provide an apparatus for
lifting or pulling heavy loads and controlling their position in
1, 2 or 3 dimensions which solves one or more of the problems
associated with the conventional methods and techniques
described above. Another object of the present invention is to
position loads vertically by ascending or descending a rope or
cable fixed above the load.
Another object of the present invention is to optionally utilize
one or more ropes or cables affixed overhead and at a distance
from one another in order to facilitate two dimensional or three
dimensional positioning of a load, be it a person or an object.
It is also an object of the present invention to be able to
manipulate a single rope, so that if multidimensional
positioning is not required, the same device can still be
utilized for powered ascent and descent in a single dimension.
It would also be desirable to be able to attach any such rope
pulling device to a rope at any point along that rope without
having to thread an end of the rope or cable through the device.
This would increase the usability of such a device considerably
over other rope pulling and climbing devices, allowing for
example a user to attach the load or himself to the device for
ascent that starts at an elevation well above the lower end of
the rope.
Other objects and advantages of the present invention will be
apparent to one of ordinary skill in the art in light of the
ensuing description of the present invention. One or more of
these objectives may include:
(a) to provide a line pulling device that can handle a range of
rope types, cables, and diameters;
(b) to provide a device that can interface with 1 or more ropes
and control each rope independently;
(c) to provide a device which does not require an end of the
rope or cable to be fixed to the device;
(d) to provide a device which provides a smooth, controlled,
continuous pull;
(e) to provide a device which itself is capable of traveling
upward along ropes or cables smoothly and continuously to raise
a load or a person;
(f) to provide a device which is easy and intuitive to use by
minimally trained or untrained personnel;
(g) to provide a device which can pay out, or descend, ropes or
cables at a controlled rate for a range of loads; - A -
(h) to provide a device which can apply its pulling force both
at high force levels, for portable winching applications, and at
fast rates, for rapid vertical ascents; (i) to provide a device
with a safety lock mechanism that prevents unwanted reverse
motion of the rope or cable; (j) to provide a device that can
attach to a rope or cable at any point without having to thread
an end of the rope or cable through the device; (k) to provide a
device that is not limited in its source of power to any
particular type of rotational motor;
(1) to provide a device that is usable in and useful for
recreation, industry, emergency, rescue, manufacturing,
military, and any other application relating to or utilizing
rope, cable, string, or fiber tension; (m)to provide a device
that can be operated remotely, either via wireless
communication, remote wired interface, or other means;
(n) and to provide a device that interprets a user's input and
translates it into the desired motion vector of the load through
space in 1, 2 or 3 dimensions.
Still further objectives and advantages are to provide a rope or
cable pulling device that is as easy to use as a cordless power
drill, that can be used in any orientation, that can be easily
clipped to a climbing harness, Swiss seat, or other static load
suspension equipment, that can be just as easily attached to a
grounded object to act as a winch, that is powered by a portable
rotational motor, and that is lightweight and easy to
manufacture. While a number of objectives have been provided for
illustrative purposes, it should be understood that the
invention described below is not limited to any one of the
illustrative objectives. It should further be understood that
these illustrative objectives are stated in terms of the
inventors' view of the state of the art, the objectives
themselves are thus not prior art or necessarily known beyond
the inventors.
SUMMARY OF THE INVENTION
The invention provides a multiple-rope or multiple-cable pulling
device that preferably accomplishes one or more of the objects
of the invention or solves at least one of the problems
described above.
In a first aspect, a device of the invention includes an
electronic controller that interprets a user's input from an
interface such as a trigger or a joystick, and preferentially
activates electronically controlled motors that drive one or
more rope pulling mechanisms, such as winches. When the winches
pull in or pay out cable in accordance with the controller's
demand, the load is moved along the desired trajectory as
specified by the user through the device interface.
An embodiment of the invention can be incorporated into a
convenient portable hand-held motorized device, and in
particular, can be configured as a portable hoist. Further
aspects of the invention will become clear from the detailed
description below, and in particular, from the attached claims.
The present invention can provide a useful solution because at
minimum, its operation only requires the space of the
straight-line trajectory through which the load and the ropes
must move, as opposed to conventional boom hoists which require
a larger work volume to accomplish the same movement.
Additionally, the installation of the present invention to
accomplish multidimensional load movement can be much lower
profile and lower impact than that of a conventional hoist, by
requiring only either 2 or 3 stationary fixture points for
operation.
By utilizing a two-rope device, the operator can position the
load or himself anywhere along a vertical plane passing through
the two rope connection points by independently and
simultaneously controlling and adjusting the lengths of the
ropes actively fed through the device during its operation. Note
that the load, here, can be an object, a person, or the
operator, and that the ropes can be replaced by cables or other
tensile elongate elements.
By utilizing a three-rope device, the user can position the load
anywhere within a three dimensional space. By adjusting the
relative lengths of rope above the device, its position can be
controlled to anywhere within the volume of space projected
downward from the three rope attachment points. Note again that
the load, here, can be an object, a person, or the operator, and
that the ropes can be replaced by cables or other tensile
elongate elements. For greater load carrying capacity or
movement within geometrically constrained spaces, such as a
warehouse with tall items obstructing the desired path of the
load, a device capable of manipulating 4 or more ropes could be
utilized to provide added positional control beyond the
capability of a 2 or 3 -rope device.
The control of a multiple rope device can be achieved through a
variety of configurations. One configuration consists of the
device presenting to the operator one interface for each of the
ropes passing through the device, be it a trigger, a switch, or
a joystick. In this case, the operator manually controls the
relative lengths and speeds of the ropes passing through the
device, causing the ropes to move in the upwards or downwards
directions as needed.
A second configuration consists of the device presenting to the
operator an interface, for example a joystick, that allows the
operator to input his intended direction for the load, whereby
the device computes and automatically adjusts the incoming and
outgoing rope lengths and speeds to accomplish the task. In the
two rope device case, with the device and operator positioned
with one attachment point above and to the left and the other
attachment point above and to the right, the operator can input,
for example, an up, down, right, or left intended direction on
the interface in order to move in that direction. Intended
diagonal directions, such as up-left, up-right, down-left, and
down-right could also be accepted and delivered by the device.
Such a configuration would be very useful for positioning the
load within a plane, for example against a wall.
This configuration can be extended to three dimensional
positioning within a volume, where again the operator inputs an
intended direction and speed, and the device computes and
delivers the corresponding three rope feed rates to move the
load in the intended direction at the intended speed.
A third configuration consists of the device operator himself
acting as the device controller. The operator may manually
indicate rope directions and speeds independently of one another
by squeezing a single trigger associated with each rope, or by
manually activating each respective motor controller by some
other means. One such configuration for 2 dimensional movement
would comprise 2 triggers, each corresponding to one rope. The
operator would pull a trigger to pull in rope, and pull a second
trigger or button to release that rope. A parallel setup would
correspond to the second rope. By preferentially pulling in and
paying out ropes via manual control, the operator can move
himself or the load along the desired trajectory. This means of
control may also serve useful as a backup in conjunction with
any automated controller associated with the device. A person of
ordinary skill in the art will note that this manual control
setup can be extrapolated to 3 rope, and thus 3 dimensional
control, and even additional ropes beyond 3 as a situation may
call for.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 provides a diagrammatic
view of a device of the invention for positioning a load;
Figure 2 provides a diagrammatic
view of the device of Figure 1 in 2 dimensional use, with
definitions of ropes and reference angles for trajectory
computation by the device controller;
Figure 3 provides a diagrammatic
view of a further embodiment of a device of the invention for
positioning a load;
Figure 4 provides diagrammatic view
of a further embodiment of a device of the invention for
positioning a load;
Figure 5 shows a schematic view of
a person operating the device of Figure 1 in 2 dimensions;
Figure 6 illustrates an isometric
view of a device according to the diagram of Figure 1 in use with two ropes and
an operator as a load;
Figure 7 provides a front isometric
view of the device of Figure 6;
Figure 8 provides a rear isometric
view of the device of Figure 6;
Figure 9 provides a rear isometric
view of the device of Figure 6 with a cover of the device
removed; Figure 10 provides a side view of the device of
Figure 9 with the cover removed; and
Figure 11 provides an additional
side view of the device of Figure 9 with the cover removed.
DETAILED DESCRIPTION
Referring now to Figures 1 and 2, a device 100 of Ihe invention
for positioning a load 110 in 2 dimensions is illustrated
diagrammatically.
A user of device 100 provides an input to the device through the
user interface 112 in accordance with the direction he wants to
move the load, be it an object, another person, or himself. The
device control 114 interprets the command and sends applicable
signals to the speed controls 116,118 in charge of each of the
rope interaction mechanisms 120,122. The signals are such that
each of the mechanisms will create a velocity vector Vi5V2 along
its own rope 124,126, which will sum with the velocity vector of
the other rope or ropes to create the desired load trajectory.
Sensors 128,130 detecting the angle [theta]i, [theta]2 of the
ropes with respect to vertical to provide position feedback to
the device controller 114, which then updates the necessary
speed of each rope feed 132,134 to maintain the desired
trajectory. The equation describing the velocity vectors of each
rope as dependent on the respective angles of each rope to
vertical is as follows:
Equation 1: Rope velocity calculation from rope angles with
respect to vertical
Where Vx is the velocity of the first rope being pulled toward
the device, V2 is the velocity of the second rope being pulled
toward the device, [theta]\ is the angle that the first rope
enters the device, 02 is the angle that the second rope enters
the device, Vx is the component of the intended velocity in the
X direction, and V[gamma] is the component of the intended
velocity in the Y direction. Note that [theta]\ and 02 are
measured clockwise from vertical at the points where the first
rope and second rope enter the device, respectively. The
intended velocity, FLOAD, is inputted by the operator through
the user interface 112, via a joystick for example, and is
proportional to the degree to which the joystick is pressed by
the operator in a given direction. FLOAD is then decomposed into
velocity components Vx and Vy. At times, Vx and Fy can be
negative or zero.
Figure 2 provides a diagrammatic view of a 2 dimensional device
100 and provides a pictographic description of the angles and
variables in Equation 1, as described above. A person of
ordinary skill in the art will note that the corresponding
velocity equation pertaining to 3 dimensional movement must
reference 2 angles for each rope in order to fully define the
load's position with respect to ground. These angles would be
measured by angular sensors positioned on the device and in
contact with the ropes, as in the 2 dimensional case. Lastly,
because the orientation of the device 100 may change with
respect to ground, it is highly advantageous to include a tilt
sensor, accelerometer, or other means of detecting the device's
orientation in space, in order to correct for any off-axis
positioning of the device itself that may occur during movement.
While closed loop feedback control could be used with this
embodiment of the invention, it is not required for operation of
device 100. With each side of the device under manual control,
for example, offering a proportional speed trigger for each rope
interaction as the user interface, a user could still achieve
satisfactory 2 or 3 dimensional positioning capability by
controlling each vector separately. Once the device controller
114 determines the requisite motor speeds to accomplish the
desired trajectory, it sends velocity signals to the respective
speed controllers 116,118, which then activate the motors
136,138, and optionally gearboxes 140,142, accordingly. The
motors 136,138 and gearboxes 140,142 then provide rotational
power to the rope pulling mechanisms 132,134, which pull the
ropes through the device 144,146. A person skilled in the art
will note that it is easy to enable remote operation of the
device by separating the user input physically from the
invention itself. User input would then be relayed to the device
either through a remote cable, a wireless communication device,
or other remote means. In a preferred embodiment of the
invention, DC motors are utilized for their high power and low
weight, though a person skilled in the art will note that the
functionality of the device can be enabled by any powered
rotational motor, or other power delivery mechanism. An
exemplary power source 148 for powering the motors, as well as
the device controller, could be a battery, especially a
rechargeable batter such as a lithium ion battery.
A rope pulling mechanism is referenced in Figure 1. The device
of the present invention can function with this rope pulling
mechanism comprising any one of a variety of existing mechanisms
designed to pull in and pay out ropes, cables, or other tensile
elongate elements under load, including but not limited to:
conventional cable winches, capstan winches, self-tailing
winches or mechanisms, grooved or splined pulleys, and other
friction drives. In a preferred embodiment, the mechanisms for
pulling ropes or other elongate tensile elements are constructed
using the principles of published PCT application no. WO
2006/113844 entitled "Powered Rope Ascender and Portable Rope
Pulling Device," which application is incorporated herein by
reference. In one embodiment, the devices of WO 2006/113844
could be used as the rope interaction devices 120,122 of unit
100.
In one embodiment, the rope pulling mechanisms comprise a
rotating drum that is connected to the motor, either directly or
through a gearbox (if one is present). It is the rotating drum,
generally in the manner of a capstan, that applies the pulling
force to the rope that is pulled through the device 100. In one
embodiment, the rotating drum provides anisotropic friction
gripping of the rope. In particular, the surface of the rotating
drum can be treated or configured so that large friction forces
are created in the general direction of the pulling of the rope
(substantially around the circumference of the drum), and
smaller friction forces are created longitudinally along the
drum so that the rope can slide along the length of the drum,
particularly when guided in such a manner by a rope guide, with
relative ease. In other configurations, including when the rope
runs over the drum for less than one full revolution of the
drum, vanes on the drum can guide the rope to the center of the
drum where those or other vanes help to grip the rope for
pulling by the rotating drum. Such vaned drums are illustrated
in Figures 9 to 11 below along with exemplary rope guides for
guiding the rope onto and off of the rotating drum. The rope
pulling mechanism, any associated rope guide, or the device 100
itself or one of its elements, may also include a brake for
holding the rope or ropes The brake may be manual actuated,
electrically actuated upon a signal from the device controller 1
14, and/or may operate continuously in a one way or ratchet mode
in which the rope may be pulled through the device in a
direction that allows the load to be lifted, but grabs or brakes
movement of the rope if the device begins to slip down the rope
or ropes
In the illustrated embodiment, the rope pulling mechanisms
132,134 and control elements 114,116, 118 are integrated into a
single unit 100 This embodiment can provide advantages when the
operator is the "load" 110 That is, a single integrated unit 100
for lifting or moving the operator is advantageous in that the
operator can use the user interface 112 to operate the device
while the operator is being lifted or moved In other
embodiments, the user interface 112, for example, could be
separated from the device 100 so that an operator could operate
the device 100 remotely to lift or move a load 1 10 other than
the operator Similarly, the rope interaction mechanisms 120,122
could be separated and not provided in an integral unit 100 Such
an embodiment might be useful under certain circumstances to
provide o[pi]entational stability for a large load - for
example, a large rectangular load might have four rope pulling
mechanisms, one on each top comer of the load, with all of the
rope interaction mechanisms communicating with a common user
interface 112 and controller 1 14 In such an embodiment, each
rope interaction device 120,122 could be provided with its own
power source 148
A rope or cable 124,126 is also referenced in Figure 1 The
device of the present invention is intended to be able to pull
any elongate resilient element that can withstand a tension
Cables and ropes are the most common of these, but the invention
is not meant to be limited by the reference to ropes or cables
A further embodiment of a device for positioning a load 200 is
illustrated by reference to Figure 3 This device 200 is set up
for 3 dimensional positioning of a load or operator within a
volume The relationship between the user input 212, device
controller 214, and rope interaction mechanisms 220,222 is the
same as in the embodiment of Figure 1, but this embodiment
includes an additional rope interaction mechanism 224 in
parallel with the first two, enabling a third dimension of load
positioning by pulling three ropes 226,228,230 through the rope
interaction mechanisms illustrated as 232,234,236. A power
source 248 can also be provided for all of the device controller
and the rope interaction mechanisms, or separate power sources
can be provided. A person of ordinary skill in the art will note
that where it may be applicable, additional rope interaction
mechanisms may be added in parallel with the first three to
enable more precise movement where needed, such as movement
around obstacles in a warehouse, or when overhead attachment
points for load suspension limit the capability of a three rope
device.
In a further embodiment of the invention, as shown in Figure 4,
the device 300 may be split into separate segments, with each
rope interaction mechanism 332,334 located at the overhead
fixture point 336,338 of each rope or cable 324,326. The load
310 is suspended between the fixture points by the ropes or
cables. To achieve multidimensional load positioning, the
fixture points of the rope handling mechanisms must be placed
some distance apart. Sensors on the device, in contact with the
ropes, indicate the rope angle with respect to a fixed axis to
provide position feedback to the device controller 314, as in
the embodiment of Figure 1. The user inputs through user
interface 312 his desired trajectory into the device controller
314, which either remotely or directly sends velocity signals to
each of the overhead rope pulling mechanisms. As the rope
pulling mechanisms appropriately pull in or pay out rope, the
suspended load is moved along the desired trajectory. This
embodiment may be suitable for more permanent installations, or
situations where having the load positioning device travel along
with the load is unfeasible. A power source 348 in this
embodiment could be centrally located for connection to the
cable interaction mechanisms 332,334 and controller 314, or,
each device could have its own power source. Especially in the
latter case, the user interface and controller could be
provided, for example, by a personal computer, or a handheld
digital device such as a PDA.
In another embodiment, the device may be fixed with respect to
ground, and the ropes or cables are guided to the load via
pulleys located on ceilings, walls, or other fixture points. In
cases such as this, where the cable position with respect to the
device would not change as a function of load position due to
both the device and the first pulleys being fixed with respect
to ground, the angular position feedback sensors would need to
be located either at the load attachment point or at the last
pulley before the load, where the angles of the ropes with
respect to a fixed reference such as horizontal or vertical
would change as a function of the load's position.
Figure 5 shows a schematic view of an operator moving in 2
dimensions using the device of Figure 1. The device 1 is
attached to a point on the load, or the harness on the operator
in this case, via the clip-in point 2. Upon the operator's input
to the device 1 to move left, the left rope in neutral position
7 is pulled into the device 1, and the right rope in neutral
position 10 is paid out of the device 1, and the operator
advances toward the left position 3. After the operator has
reached the desired left position 3, the left rope has been
advanced to its left position 6 and the right rope has also been
moved to its left position 9. Upon the operator's input to the
device 1 to move toward the right, the left rope 6 is now paid
out of the device, and the right rope 9 is pulled into the
device, thereby translating the operator toward the right
position 5. At this final point, the right rope is now in its
right position 11, and the left rope is also in its right
position 8, and the operator 5 is suspended in his desired
place.
Figure 6 depicts a three-dimensional view of the device operator
4, hanging in neutral position from a preferred embodiment of
the device 1. The operator 4 is tethered to the device's clip-in
point 2 via a tensile lanyard 18, both of which are visible in
Figure 7, as well as other Figures. The device is high enough
above the operator that he can utilize the device for
positioning without the device obstructing his work envelope. As
depicted in Figure 5, the left rope 7 goes into the left rope
interaction 12, and the right rope 10 goes into the right rope
interaction 13. Control is achieved by adjusting the joystick 17
on the control box 16, which is attached by a short coiled
remote cable 15 to the device 1. This allows the device to
remain overhead and out of the way, while still allowing easy
controllability for the operator.
Figures 7 and 8 show an embodiment of the invention. The ropes
enter the left rope interaction 12 and right rope interaction
13, and exit each respective pulling mechanism on each side. A
plastic housing 14 covers the chassis and internal components of
the device for ruggedness and safety. A coiled remote cable 15
brings electrical signals back and forth from the control box 16
into the device, and the joystick
17 shown on the control box 16 is a preferred method of control
for 2 or 3 dimensions. The operator attaches himself to the
clip-in point 2 via some tensile lanyard 18, which may be long
enough to hang the operator well below the device such that his
work envelope is not obstructed by the device. A carrying handle
19 offers easy transport to and from a work or rescue site.
Figure 9, 10 and 11 depict an embodiment of the invention
without the plastic housings 14 installed. The left and right
rope interactions 12 and 13 are shown without their safety
covers, and all underlying components are exposed for viewing.
The battery pack 24 supplies electrical power to the motor
controller 25, which may contain two or three separate channels,
depending on the number of separate rope interactions in the
device. One channel is required for each interaction. In this
case, a dual channel controller is utilized. The motor
controller 25 preferentially applies power to one motor
22 or the other so as to move the load along the desired
trajectory. Referring to the left side only for the purpose of
this description, the motor 22 applies a rotational torque at a
velocity to the backside of the gearbox 21, which then applies a
different torque at a different velocity into the left rope
interaction 12. Operation is identical for the right side, but
with the motor, gearbox, and rope interaction pertaining to that
side. The chassis structure 20 holds the components together and
provides the tensile elements from which the load hangs.
For safety, an electromechanical safety brake 23 is attached to
the back of each motor 22. Such a safety brake requires
electrical power to disengage. Before applying power to the
motor 22, the motor controller 25 must apply power to the safety
brake 23 to release its grip on the back end of the motor shaft.
Upon release, the motor 22 can rotate and power the rope
interaction to which it is attached. When in the unpowered
locked position, the brakes provide a mechanical lock to the
rope interaction mechanisms that prevents unwanted motion of the
device and load. Thus, even upon power failure, the device and
load will remain safely held in place. A person skilled in the
art will note that such a brake could be installed on either end
of either the motor or gearbox to achieve this safety
functionality. Additionally, any suitable power-off brake,
whether pneumatically, mechanically, or otherwise released, can
provide the same safety functionality as described. The
illustrated embodiments can utilize a high-power DC electric
motor, as built by Magmotor Corporation of Worcester, MA (part
number S28-BP400X, for example) which possesses an extremely
high power-to weight ratio (over 8.6HP developed in a motor
weighing 7 lbs). The power source can include batteries such as
24V, 3AH Panasonic EY9210 B Ni-MH rechargeable batteries. The
device incorporates a pulse- width modulating speed control,
adjusted by the device controller, that proportionally changes
the speed of the motor. The controller can be implemented on a
variety of digital microprocessor devices with instructions and
calculations coded in software, firmware, or the like.
A person of ordinary skill in the art will recognize that a
variety of sensors will suffice to provide positional feedback
to the device controller. In the preferred embodiment, angular
sensors located on the device indicate the rope's angle with
respect to a fixed reference, such as horizontal or vertical. In
the alternative embodiment, the angular sensors can be located
on the overhead rope pulling mechanisms or at the load
attachment point. Other examples of sensors that could work
include but are not limited to: rotary encoders on the motors or
the outputs of the rope pulling mechanisms, linear or rotary
sensors in contact with the rope, optical sensors on the device
detecting the length of rope pulled through, and accelerometers
on the device that provide inertial position, velocity or
acceleration feedback.
A person of ordinary skill in the art will also recognize that
the configurations described above are not the only
configurations that can employ the principles of the invention.
The system and method described above, utilizing multiple rope
or cable pulling mechanisms to position loads in 2 and 3
dimensions, can be practically employed in other configurations.
While certain features and aspects of the illustrated
embodiments provide significant advantages in achieving one or
more of the objects of the invention and/or solving one or more
of the problems noted in conventional devices, any configuration
or placement of all the parts, user interface, device
controller, speed controller, power source, gearbox, sensors,
and rope pulling mechanisms with relation to one another or to
ground could be deployed by a person of ordinary skill in
keeping with the principles of the invention.
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