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Airplane Inventions



During the 1920s, 30s, & 40s, several excellent aerotech inventions appeared that somehow got lost in the meanwhile since then. Here they are, 60+ years later, waiting to be rediscovered by you:

George Cornelius: Free-Winged Plane
Willard Perry: Nose Vanes
Ray Thompson: Magnus-Effect Wing
Vicomte de Rouge: Stabilizer
Julius Fox: Air-Cushion Wing
A. Flettner: Magnus-Effect Propeller
J. Irving: Propeller
Emil Doehler: Wing Tips
Charles Laurent: Wing Tips
H. Randle: Wing


George Cornelius: Wing

Popular Science (May 1931)

"Free-Winged Plane Able To Fly Itself"

Successfully demonstrating in test flights that it practically can fly itself, land or take off without the aid of a pilot and cannot stall, spin, sideslip or stunt, a new "free-wings" airplane is scheduled to be produced on a large scale by its Los Angeles designer, G. Wilbur Cornelius.

The monoplane differs from orthodox aircraft in that its wings are not rigidly fixed to the fuselage by are free moving, automatically adjusting themselves to air bumps, acting as elevators and ailerons combined.

Attached to the trailing edge of each wing is a paddle-like trigger assembly --- "stabilators" that can be adjusted so the ship will maintain any desired gliding or climbing angle.

All the pilot has to do in landing is to cut of the plane's motor and set the stabilators for the correct gliding angle. The craft is steered by a conventional rudder at the tail, but its free moving wings automatically put the plane into a bank while turning.

Tests showed that the craft cannot stall because the center of gravity is located so as to cause the wings and stabilators automatically to keep the craft in a position that will not allow it to lose flying speed. The plane can be force into off-center maneuvers, but rights itself to an even flying keel when the pilot takes his hands off the controls.


Popular Science (July 1932)

"Floating Edge on Wing Keeps Plane Out of Tail Spin"

An airplane designed by G.W. Cornelius, California aviator and inventor, has wings hinged at the front so that the trailing edges can move up and down in response to variations in wind pressure and "bumps" in the air. He claims that a tailspin is impossible with this construction, and that the plane will fly virtually without manual control.

This remarkable plane ha no ailerons as used on conventional types of ships, the 13-degree movement of the wings making them unnecessary. Not in the picture below the dropped position of the wings with relation to the fixed center, and the special supports to the trailing edges of the wings as pointed out by Cornelius.


US Patent # 1,865,744
Airplane

George W. Cornelius
(July 5, 1932)

This invention relates particularly to airplanes.

An object to the invention is to provide an airplane assembly including fuselage, wings, tail, and propeller, arranged so that the propeller, wings and tail, individually or collectively, may be moved out of a normal position relative to the fuselage to control directional movement of the airplane.

A further object of the invention is to provide an airplane fuselage having wings projected from opposite sides of said fuselage, each wing on each side of the fuselage being independent of the other and being rotatably secured to the said fuselage to be moved above or below a predetermined normal position.

A still further object of the invention is to provide an airplane fuselage having wings on opposite sides thereof, in a substantially horizontal position, adapted to be rotated above or below a horizontal plane, said wings being connected to a mounting supporting the propulsion medium, and to a mounting supporting the tail, whereby the said propulsion medium, wings and tail may be moved in synchronism to steer the airplane into any selected line of flight.

Other objects of the invention are to provide a device of the character described that will be superior in point of simplicity, inexpensiveness of construction, positiveness of operation, and facility and convenience in use and general efficiency.

Other objects and advantages will appear as this description progresses.

In this specification and the annexed drawings, the invention is illustrated in the form considered to be the best, but it is to be understood that the invention is not limited to such form, because it may be embodied in other forms, and it is also to be understood that in and by the claims following the description, it is desired to cover the invention in whatsoever form it may be embodied.

In the accompanying drawings,

Figure 1 represents a plan view of an airplane having a wing and fuselage constructed in accordance with my invention.

Figure 2 is an enlarged cross-section taken through Figure 1 on the line 2-2.

Figure 3 is an end view of a fragmentary portion of the fuselage and one of the wings to show the wing supporting structure.

Figure 4 is an enlarged cross section taken through the joint where the wing is secured to the fuselage, on the line 4-4 of Figure 2.

Figure 5 is an enlarged cross section taken on line 5-5 of Figure 3, showing a method of movably confining the movable edge of the airplane wing to the fuselage.

Figure 6 is an enlarged section taken through Figure 3 on the line 6-6 to show a method of movably securing the wing structure to the fuselage.

Figure 7 is a diagrammatic side elevation of an airplane having a wing structure mounted thereon in accordance with my invention, connected to the mechanism for manipulating said wing and also showing the controlling mechanism connected to a propeller mounting and tail mounting to be moved in synchronism with the wings or independently thereof.

Figure 8 is a plan view of Figure 7.

Figure 9 is a side elevation of a fragmentary portion of an airplane of the biplane type in which both of the planes are connected to the fuselage by the same form of connection as that employed in securing the single plane shown in Figure 7 to the fuselage.

Figure 10 is a side elevation of the controlling mechanism for the wing, engine mounting and tail.

Figure 11 is a rear view of Figure 10.

Figure 12 is a side elevation of a portion of Figure 11 taken on the line 12-12 of Figure 11.

In detail, the construction illustrated in the drawings comprises an airplane fuselage generally designated b numeral 1. As in conventional airplane construction, the fuselage is provided with wings 2 and 3 on opposite sides of the forward end of the fuselage, forming a monoplane, and shown in Figure 9 with a pair of wings 4 and 5 on each of the opposite sides of the fuselage to form a biplane. The forward end of the fuselage 1 has a motor 6 universally mounted therein, to which a propeller 7 is secured. The rear end of the fuselage had a tail 8 flexibly mounted thereon.

In a conventional type of airplane, either of the monoplane or biplane type, the wings are fixedly secured to opposite sides of the fuselage, and an aileron A is mounted on the trailing edge thereof, to control the balance of the airplane in flight, and to maintain a relatively stable equilibrium of the said airplane during flight. Likewise, airplane engines are ordinarily mounted in fixed position within the forward end of the fuselage, and the rear end of the said fuselage is provided with a rudder and a tail controlled by the operator for steering the plane either to the right or left and upwardly or downwardly. From my experiments, I have discovered that the wings 2 and 3 of an airplane may be pivotally mounted on opposite sides of the fuselage 1 so as to have a limited movement above or below a horizontal level to effect a stable equilibrium of the airplane while in the air, with the same effect that the balance of the airplane is accomplished through the medium of the ailerons. Obviously, the movement of the wings above or below a predetermined horizontal flying position will either hasten the ascent or descent of the airplane, or hasten the turning of the plane either to the right or to the left, this to increase the efficiency of the plane in moving in any direction in the air beyond what the directional movement of the airplane would be when controlled by the conventional aileron and tail and rudder system.

The wings 2 and 3 are each provided with a tapered tubular support 9 therein, each support in turn having laterally disposed tubular supporting webs 10 extending therefrom along its entire length, to form a foundation for the wing covering, to be mounted around and to enclose the entire tubular assembly. Each of the main supports 9 are closed at 11 at the meeting ends, so that the interiors of said supports may be used as fluid supply tanks. The ends 11 of the wing supports 9 meet centrally within the fuselage, secured adjacent the upper part of the fuselage. Each support 9 is provided with a bolt 13 thereon that projects through a slot 14 in the bearing, and nut 15 is secured to each bolt to hold the wing supports 9 from becoming axially displaced. The slot in the bearing 12 permits the supports 9 to have a limited rotative movement.

In view of the fact that the construction of each wing is identical, the following description will be confined to one wing only, and it is to be understood that a similar construction and operation applies to the other wing structure assembly. I do no intend to rely wholly upon the wing supports 9, mounted in the fuselage bearing, to carry the entire stress of the wing in flight, as I have discovered that it is better to reinforce the wing structure by means apart from the main bearing.

Adjacent the trailing edge of the wing, next to where same abuts the fuselage 1, I have provided a bracket 16 having a roller 17 rotatively mounted thereon and with an end thrust roller 18 journaled across the end of said bracket. Both of the rollers 17 and 18 are movably confined within an arcuate and channel shaped guideway 19 that is secured to the outside of the fuselage 1. The length of the arcuate guide is determined, to regulate the length of the swinging movement which it is desired that the wings shall have. The channel shaped guideway 19 holds the wing rollers 17 and 18 therein, allowing said rollers to move freely in the guideway, as the wing is turned relative to the fuselage. The rollers in the guide way 19 prevent the edge of the wing 2 from getting out of abutting contact with the fuselage 1.

Each of the wings 2 and 3 are also provided with struts 21 secured to a mediate portion of the wing, and said struts extend downwardly through an arcuate guide 22 provided along the bottom of the fuselage. The end 23 of each strut 21 within the arcuate slot 22 is provided with rollers 24 rotatably mounted thereon, to permit the lower end of said strut to move relatively free from one end of the guide way to the other. An end 25 of the strut 21 extends through the fuselage into the interior thereof, and is provided with an eyelet 26 thereon to which a control wire 27 may be fastened that connects to the operator's control stick 28, for tilting the wing above or below its normal horizontal pane, according to the desires of the airplane operator.

The control stick 28 for moving the wings upwardly or downwardly, consists of a pair of spaced members 29 and 30 having a bearing block 31 rotatably mounted therebetween. The bearing block is rotatably mounted on a fixed shaft 32 that extends transversely across and is secured to the airplane fuselage. The fixed shaft 32 permits the control stick 28 to be moved fore and aft or rotated therearound within a limited degree, and at the same time the control stick may be rotated sideways in either direction. A shaft 33 is journaled across the upper end of the control stick 28, and has a steering wheel 34 mounted on an end thereof. The shaft 34 is also equipped with a pair of teethed sprockets 35 and 36 thereon, confined between the opposite sides 29 and 30 of the control stick. An idler pulley 37 is rotatively mounted adjacent the lower end of the control stick. A chain 38 passes around the sprocket 35 on the upper end of the control stick, and one end of said chain is fastened to a wire 39 that passes around the lower pulley 37 in the control stick, and then passes around a pulley 40 on the side of the fuselage 1 and thence is connected to the end 26 of the strut support of the wing 2 that extends within the fuselage. The opposite end of the chain has a wire 41 connected thereto that extends around the lower pulley 37 in the control stick and continues to the opposite side of the fuselage, passing around a pulley thereon, 42, and thence to connection with the lower end 26 of the strut 1 of the wing 3 that extends within the fuselage.

A chain 43 extends around the other sprocket 36 on the steering wheel shaft, and thence around a pulley 44 that is journaled on the control stick 28 directly beneath the sprockets on the upper end of said stick. One end of the chain 43 has a wire 45 secured thereto that passes around a pulley 46 on one side of the fuselage 1 and thence around a pulley 47 positioned to the rear of the arcuate guideway 22 and thence to connection with the strut end 26 of wing 3. Rotative movement of the steering wheel 34 will cause the wing 2 on one side of the fuselage to be elevated while the wing 3 on the opposite side of the fuselage will be lowered. This selective movement of the wings in opposite directions will control the turning movement of the airplane in exactly the same manner as a conventional airplane may be turned through the medium of the ailerons. It should be noticed the wire connections from the control stick 28 to the wings extend from opposite ends of the pivotal center of the control stick. Thus by swinging the control stick 28 about its pivotal axis 32, both of the wings 2 and 3 on the opposite sides of the fuselage 1 may be moved simultaneously in either an upward or downward direction. My method of mounting the airplane wings 2 and 3 on the fuselage, permits said wings to be simultaneously moved in opposite directions, and also permits both of the wings to be raised or lowered in unison. Although I have described particularly the method of operating the wings of an airplane of the monoplane type, exactly the same operation takes place with an airplane of the biplane type, as shown in Figure 9. The wings 4 and 5 shown in Figure 9 being raised or lowered through the same type of mechanism as that heretofore described.

In Figure 7 of the drawings, I have shown an engine 6 that is universally mounted in the fore end of the fuselage 1. The engine 6 is provided with a propeller 7 thereon, and the universal mounting of the engine is such that the propeller and engine may be moved out of a normal position in axial alignment with the fuselage into any selected angular position of any desired line of flight. The universal mounting of the engine in the airplane fuselage is more particularly illustrated and described in the pending application that I have filed. The engine mounting 6 is provided with four wires, 50, 51, 52, and 53 thereon that lead to opposite ends and opposite sides of the pilot's control stick 28 so that the engine and propeller may be moved in any desired direction.

The airplane tail 8 mounted at the rear end of the fuselage, is universally secured to the said fuselage 1 in a ball mounting, whereby said tail may be moved up or down and to the right or left, through control means connected to the operator's stick 28. This ball mounting for the tail is more particularly illustrated and described in a separate pending application. The tail 8 is provided with an arm 55 that extends into the interior of the fuselage of the airplane, and said arm has two bars 56 and 57 arranged at right angles to each other, secured at the end of said arm 55. Control wires 58, 59, 60 and 61 are suitably connected to the ends of the cross bars 56 and 57, and said wires are passed around pulleys 62 and are joined to the ends of cross bars 63 and 64 that extend out from the stick 28 at the point of its pivotal connection to the fuselage. Thus, as the operator turns the control stick 28 forward or backward or turns it to the right or left, the wires connecting the stick 28 to the tail 8 cause the tail 8 to be moved either to the right or left or up or down. The tail of any airplane is used to control the up and down movement of the said vehicle, and to balance the said vehicle while in flight. In a case where the airplane would be out of balance, or the weight carried by the plane would be improperly stowed, and the said airplane would be in a more or less unstable condition, this condition would be rectified by forcing the tail out of the normal operating position to compensate for the unstableness of the plane. In the event that the tail 8 would have to continuously be maintained above or below its normal horizontal position, it would require the aviator pilot to hold the control stick 28 either forward or backward of its normal vertical position, to maintain the tail in the proper balanced operating position. Obviously, this would have the effect of placing the wings 2 and 3 or the propeller mounting 6 slightly out of the normal position. Therefore, in order to maintain the propeller mounting and the wings in a normal position of flight, and to allow the tail 8 to remain out of normal position, I provide a pair of wires 65 and 66 that are connected to the top and bottom of the arm 55 that extends into the fuselage from the tail 8. these wires 65 and 66, at their forward ed are provided with a sprocket chain 67 that passes around a sprocket 68 journaled on the control stick supporting shaft 31. The sprocket 68 is provided with a casing 69 thereon in which a latch member 70 is reciprocatingly mounted. The latch member 70 registers with the toothed rack 71 that is fixedly mounted in the stick 28. Thus, where the control stick 28 is out of its normal vertical position to hold the tail up or down to keep the airplane in proper flying position, the latch 70 permits the sprocket wheel 68 to be turned to maintain the tail 8 in its out-of-the-normal position but to allow the control stick 28 to be moved into its true vertical position. The disalignment of the tail control 8 relative to the propeller 7 and wings 2 and 3 can be corrected by moving the sprocket wheel 68 relative to the control stick 28 after the cause of the unstable condition of the airplane has been removed.


Willard Perry: Nose Vanes

Popular Science (February 1931)

"Vanes In Front Give Plane More Speed"

An odd-shaped device is the invention of W. Parker Perry of Somerset NJ, for increasing airplane speeds. A series of small vanes, looking something like paper pinwheels made by children, is mounted in front of the propeller hub. It is designed to create a partial vacuum before the machine, adding to its speed by decreasing the resistance.

On the first test flight at Roosevelt Field, NY, it is said to have increased the speed of a standard plane by 10 miles an hour. The inventor says he got the idea for his device from the shape of a posthole drill on his farm.


US Patent # 1, 973,266
Propeller Construction For Aircraft

Willard P. Perry
(September 11, 1934)

This invention relates to airplanes.

It is an object of the invention to provide means for lowering the air resistance offered to the passage of the airplane through the air.

Other object so the invention are to produce increased propelling thrust and lifting power, and to provide improved control of the airplane.

With these general objects in view, the invention consists in the features, combinations, arrangements and details which will first be described in connection with the accompanying drawing and then more particularly pointed out in the appended claims.

In the drawing:

Figure 1 is a side view of the front part of an airplane, to which my invention is applied;

Figure 2 is a front view of the airplane; and
 
 

Figure 3 shows a blank from which is formed a blade in accordance with the invention.

Figure 4 is a cross section taken on line 4-4 of Figure 2.

Referring more particularly to the drawing, the numeral 10 designates the front part of the fuselage of the airplane. On the front of the fuselage is mounted a bladed propeller 11. This propeller is on a horizontal shaft 12, as in the usual airplane construction, and this shaft is driven by the internal combustion engine of the airplane to rotate the propeller.

The invention in its entirety involves means for lowering the resistance offered to the passage of the airplane through the air. In the present best practice of the invention, the lowering of resistance is accomplished by evacuating the air in front of the fuselage and the center of the propeller. Although capable of various constructions, in the present embodiment, the air evacuating means comprises blades 13 which rotate with the propeller. As shown here, the blades are affixed to the front of a rotary body such as a disk 14 which is suitably fastened to the shaft 12 in front of the propeller and rotates with the shaft and propeller. Each blade is arranged at an angle to the radius with the inner end in advance, considered in respect of the direction of rotation.

When the propeller disk and blades rotate, the air in front f the propeller blade is sucked in at the axis of rotation, passing outwardly in said pockets and thrown into the rotating propeller blades. There is thus created a suction in front of the disk which lowers the air resistance (both frontal and skin resistance) offered to the passage of the airplane, facilitates its travel and provides increased speed. The density of the air acted upon by the propeller blades is increased by the added quantity delivered by the rotating blades with the result that the propeller develops a greater propelling thrust. This increased air density acts on the wings to augment the lifting power and makes it possible to reach higher elevation and is also felt on back on the tail surfaces to provide better control.

The present embodiment includes an advantageous form of blade. As here shown, the blade is of sheet metal, bent to form a front or under face or side and a slightly larger rear or outer face whereby the blade seats angularly against the face of the disk, forming the packet therewith, and is progressively thicker in cross-section toward the disk for the purpose of strength. The particular blank shown in Figure 3 is adapted to be bent along lines 21, 22 to form the inner face 23, the larger outer face 24 and an end 25. The bent edge 2 forms the advance or cutting edge of the blade. The blade is seated against the body or disk 14 and welded or otherwise attached to it. Unattached adjoining edges of the blade are also preferably welded.

Any number of blades sufficient to evacuate the air immediately in front of the propeller may be applied to the disk but each blade should advantageously be arranged at the same angle to the radius.

A certain amount of power is needed to rotate the disk and its blades but the advantages resulting from their employment more than offset the power thus used





Ray Thompson: Magnus-Effect Wing

Popular Science (February 1932)

"Rotor On Wing Adds To Plane's Power"

A new application of the rotor principle to airplanes is proposed by inventor Ray Thompson of Hollywood, CA,. By placing a rotating spool at the center of a model airplane wing of otherwise conventional design, Thompson declares the lifting power has been greatly augmented. The effect of the rotor is to increase the partial vacuum above the wing and the pressure of air below it.


[ Photos courtesy of Mr Bewley at UC San Diego ]


Vicomte de Rouge: Control Vane

Popular Science (April 1934)

"Vanes On Mast Keep Glider Level"

Successful in its first test flights, a glider with an unconventional stabilizing device has been introduced by a French inventor. The stabilizer, carried on a mast above the wing, is used to correct any tendency to pitch forward or sideslip in flight. Its two hinged vanes are so wired that they may be folded flat or spread sideways by a control in the hands of the pilot, and thus stabilize the plane.


Popular Science (May 1932)

"Something New For Flying"

Below, Vicomte de Rouge, a French engineer and inventor, seated in his strange tailless plane. Opening the hexagonal control on the mast directs the plane upward and closing it guides it down. The rudders on the wing tips are used to steer the queer craft.


Julius Fox: Wing

Popular Science (May 1925)

"Air-Cushion Wing"

An escalloped airplane wing invented by Julius Fox, of Cleveland, Ohio, is designed for safer landing. Its peculiar construction, he says, creates cushions of air, lessening the machine's angel of descent. A new wing rib also is shown.


A. Flettner: Propeller

Popular Mechanics (August 1925)

"Remarkable Rotor Propeller For Airplanes"

59% increase in pulling power is claimed for an unusual new rotor propeller for airplanes designed on somewhat the same principle as the Flettner rotor sailing ship.


James Irving: Propeller

Scientific American (July 6, 1918), p. 14

"An Air Screw That Ridicules Propeller Theories"

Were it not for the stern theories regulating the design of air screws, we would not be using propellers today which differ but little from those of the pioneer panes. Indeed, while airplanes and engines have been constantly improved during the past 10 years, the air screw --- the most important member of any aircraft --- has remained practically at  a standstill, due to the adherences of propeller makers to those orthodox theories which no one dared violate.

It has, therefore, remained for James A. Irving of New York City to disregard most air screw theories and strike forth along new lines. As a result, he has invented a new propeller or tractor screw of radical design which, according to the testimony of several well-known aviators who have tried it on their machines, presents a definite advance in air screws.

Essentially, Mr Irving's device is two propellers in one, as will be noted in the accompanying illustrations. In the working model shown, one set of blades is 8 feet 6 inches in diameter, while the other is about 20% shorter. The longer blades may be termed the leading blades, while the shorter ones may be termed the auxiliary blades.

The blades are built up of 3-ply ash and mahogany, the latter being laminated crosswise of the grain of the two outside strips of ash; this arrangement, the inventor holds, is positive insurance against splitting. The blades are mounted upon Monel metal arms the shanks of which are taper-fitted to a two part hub of the same metal, provided with sockets for the purpose. The tapered shanks are drawn home and securely held by means of specially designed llock-nuts, to any desired pitch which may be graduated upon the shanks and hub sockets.

In the side view of the new propeller it will be noted that the arms and blades have a dihedral arrangement, which calls for an explanation. There are four reasons for this design, according to the inventor: First, in effecting centripetal action, drawing and forcing air to the center, thus eliminating radial slip; second, applied to the auxiliary blades for the purpose of gripping and concentrating the air, effecting a powerful center thrust at the pint where the conventional propeller is absolutely void of impelling force; third, the effect upon the long, leading blades where centrifugal force against great air pressure, is to relieve the blades of practically all except lateral and torque strains; fourth, owing to the fact that the tips of the blades are kept under a rigid, constant tension between centrifugal force and air pressure, vibration or fluttering is reduced to a minimum or entirely eliminated, and this leads to a considerable correction of the very objectionable whir or hum of the conventional type of propeller. In fact, the proof of the latter is indisputably brought out in an electric-fan blade of similar design invented by Mr Irving, which is now being offered as the regular equipment of a well-known electric desk-type fan, and which is practically silent.

Structurally, the new propeller has distinct advantages. The hub of the new air screw becomes part of the engine, and any changes in blades for any reason can be easily made. Extra leading blades can be carried in the airplane for emergency use. In cases of ordinary propeller breakage were but one or even both of the leading blades would be damaged, the cost of repairs would not exceed one-third of the net cost of the complete propeller; in short, fully 50% of the new propeller would be practically indestructible, outliving several motors.

An ingenious arrangement is provided for the ready balancing of the companion blades. Small lead washers are placed in holes in both blades, and by transferring washers from one hole to another balance is soon established. The washers are held in place by a screw in each hole.

One of his objects in making the auxiliary blades shorter than the leaders, explains Mr Irving, is for the purpose of obtaining an advanced, differential pitch with which to create impelling force from the inner, slow-speed circle or "dead" space; and results from numerous practical flying tests quite justify the claim that the propeller is fully one-third more efficient than the usual design, and at no extra cost of power. When used as a tractor, the concentrating action of the auxiliary blades results in enveloping the fuselage for its entire length within a cylinder of air wash of somewhat less diameter than the short blades. It is also apparent that these auxiliary blades serve still another and valuable purpose, namely, that of forcing or assisting the leading blades into undisturbed air. But Mr Irving is not given to theories: he merely states that he has a propeller that does the work, and that it is more or less inconsequential to the practical aviator just how it does the work.

Considerable success has attended the use of Mr Irving's marine propeller, designed along the same general lines as his present air screw. Some years ago captain Baldwin, a well-known figure in American aviation, tested one of Irving's propellers on his "Red Devil" biplane. Crude as that propeller was, the results were most gratifying. Captain Baldwin was astonished with the climbing power and speed of his machine so equipped. Other aviators have also been impressed in the same way, after a trial of the propeller which ridicules propeller theories.


US Patent # 1,022,846
Propeller

James A. Irving
(April 9, 1912)

My invention relates to propellers, and more particularly to aeroplane propellers.

Experiments have shown that there is distortion when cutting a thread in a solid substance of great resistability. When a thread is cut in such an elastic medium as air, which has little normal resistibility, this distortion is greatly increased. This distortion is analogous to the disturbing of the air by a rotating propeller. Investigators of aerial propellers arrive at the conclusion that the less a propeller disturbs the air the greater its efficiency, and that a theoretical propeller of infinitely minute thickness and weight would travel through the air without disturbing it its exact pitch distance when rotated one revolution, if we disregard the frictional surfaces of the blades; but as it is impossible to construct such a propeller or avoid frictional surfaces, the problem must be resolves with a propeller constructed for practical work, which must necessarily have thickness, weight, area and frictional surfaces. Such a propeller will set up disturbances in the air which practically preclude its being considered as a screw, because these disturbances influence or distort the air, and it does not offer the necessary resistibility for cutting a screw thread. In constructing propellers for aeroplanes, great care must be taken to see that the design is such that the propeller will not throw the air laterally. This is so for the efficiency of a propeller is due to its ability to grip the air, form it into a cone and give to it volume, weight and velocity, the sum of these being a mechanically created cyclonic force which, projected against substantially inert air, propels the aeroplane at the necessary speed to exert elevating and sustaining power. Smoke and vapor experiments tend to prove that a propeller draws or absorbs air from the space around it. This air is condensed and takes the form of a truncated cone, with a slightly rotating movement, and is really a modified cyclone as the action and effect are almost identical.

My propeller has been so designed not only to disturb the air as little as possible, but the blades are adjustable relatively to each other and to the hub, to permit of a ready adjustment of the blades with reference to the weight, the resisting surface, and the frictional surfaces of the aeroplane, and the normal speed of the engine.

Additional objects of the invention will appear in the following complete specification, in which the preferred form of my invention is disclosed,

In the drawings, similar characters of reference indicate corresponding parts in all the views, in which: ---

Figure 1 is a rear view of my propeller;

Figure 2 is a plan view of Figure 1, partially in section;

Figure 3 is a transverse sectional view showing the two propellers mounted on one of the shanks;

Figure 4 is a view of a propeller blade with one of its side members and the manner of securing it to the shank;

Figure 5 is a side elevation showing one of the hub members;

Figure 6 is a face view showing a hub member;

Figure 7 is a plan view similar to that shown in Figure 2, but showing another adjustment of the propeller blades;

Figure 8 is a fragmentary view, showing each shank divided with one of its members disposed in an opening in the other to permit of the rotation of one blade on the shank relating to the other; and

Figure 9 is a sectional view on line 9-9 of Figure 8.

By referring to the drawings, it will be seen that a hub is provided, consisting of members 10 an 11, there being two roughened concave bearing surfaces 12 on the inner face of each of the hub members 10 and 11. As shown in Figures 5 and 6 of the drawings, I prefer to cut channels 13 in the hub and insert in these channels 13 bearing members 14, having the roughened concave bearing surfaces 12 referred to. The bearing members 14 are held in place by means of screws 27, and I prefer to have them project beyond the sides of the hub members. The bearing members 14 on one of the hub members co-act with the bearing members 14 on the other hub members, to grip the shanks 15 on which the propeller blades 16 and 17 are mounted. As will be understood by referring to the drawings, the bearing members are so disposed relatively to the axis of the hub, that the shanks 15 will be disposed at an angle to each other, and obliquely relatively to the hub axis. With this construction two of the propeller blades are normally disposed in advance of the hub, the other two propeller blades extending rearwardly of the hub. There are threaded orifices 18 in the hub members, which register with each other, and in these threaded orifices mesh screw members 19, having angular heads 20. Nuts 21 are provided for locking the screw members in place, and a face plate 22 with angular openings 23 is provided, the angular heads 20 being normally disposed in the angular openings 23, the face plate 22 being secured to the hub member 11 by means of screws 24. Two of the propeller blades are constructed by providing side members 25, which are bolted to opposite sides of the shank 15, as shown in Figures 3 and 4 of the drawings, the peripheries of these side members 25 being secured together at 26 by any preferred means.

As will be seen in referring to Figures 2 and 7 of the drawings, the propeller blades 16 are considerably larger than the propeller blades 17, and these blades 16 are preferably the leading blades; that is, I prefer to have them extend in a direction in advance of the hub, the shorter blades 17 extending rearwardly of the hub. It will readily be understood that by removing the face plate 22, and unscrewing the screw members 19, the shanks 15 may be rotated as my be desired to secure the desired pitch for the propeller blades, and that the shanks 15 may also be shifted longitudinally to position the propeller blades at predetermined distances from the hub. Each of the shanks 15 is divided by marks 15a, which may be referred to in obtaining the desired adjustment. The arrangement of one forwardly extending set of propeller blades in combination with one rearwardly extending set of similar blades tends to prevent a vacuum forming around the hub of the propeller, and thereby removes undesirable suction.

In Figures 8 and 9 I have shown a divided shank consisting of a tubular member 15b having longitudinal slots 15c, the shank member 15d being disposed in the tubular member 15b. When the tubular member 15b is gripped by the bearing member 14 it will press against the shank member 15d and hold the tubular member 15b relatively to the shank member 15d. With this construction the blades 17 may be disposed at any predetermined angle with relation to the blades 16.

It will be understood that the smaller or inner blades 17 may be set to a much greater pitch than the larger leading blades 17 and that the diameter of the larger blades 16 may be expanded as desired. When the positions of the blades 16 are not changed relatively to the positions of the blades 17, any increase in the pitch of one set of blades will reduce the pitch of the other set of blades. The adjustability of the propeller permits of the balancing and the setting of the blades of the propeller at the desired pitch forced to produce the best results.

Having this described my invention, I claim as new and desire to secure by Letters Patent" --- [Claims not included here]


Emil Doehler: Wing Tip

Popular Science (November 1940)

"Floating Wing Tips Give Added Safety To Light Plane"

For combining safety features of unusual variety, in designing a light monoplane for private flyers, Emil Doehler of Buffalo, NY, has won expert commendation. Vertical flaps of his own inventions, flanking the rudder, supplement standard wing flaps as "air brakes". Turned inward, they help to reduce landing speed --- eliminating side-slipping or "fishtailing" into a small field --- and also concentrate air flow upon the rudder, so as to retain effective control. Wing slots, at leading and trailing edges, assure needed lift by providing an even stream of air over the surface. Ailerons mounted on "floating" wing tips, which line up with the wind like weathervanes, give full response at angle of attack large enough to make ordinary ailerons ineffective. After a 3-point landing, using a tail wheel, the craft settles forward upon a tricycle landing gear and wheel brakes bring it to a quick stop. Hinged wings will swing hack against the fuselage, to reduce the cost of rented hanger space. In bad weather, a pilot could make an emergency landing on a highway, fold the wings, and drive away. Because of the roadability of the machine., the designer has added a propeller guard.


Popular Science (September 1939)

Charles Laurent: Wing Tip

"Plane's Wing Tips Slow Landings"

Safe airplane landings at speeds as low as 20 mph are said to be made possible by retractable wing tips invented by Charles Laurent, a French pilot. As pictures in the photograph, the extra tips are built into slots in the ends of the wings and mechanically controlled so that they can be moved outward, forming extensions of the wing surface to increase the lateral stability of the plane as slow speeds.


H. Randle: Wing

Popular Science (1924)

A novel model of a helicopter airplane, which the inventor claims will carry four times the weight of present types with one quarter of the power, has been patterned on some of the mechanical principles used by birds in flight. The upper and lower wings slope forward until they meet in a horizontal edge that cleaves the air.

By opening the V-shaped wings and slowing down the motor, the inventor, Dr H. T. Randle, of Lawrence, KS, says the machine can land on any flat-roofed building.