US3801047A

US3801047A - Omnidirectional aircraft

Info

Publication number: US3801047A
Application number: US00223454A
Authority: US
Inventors: Aquila J Dell
Original assignee: WENDROS CO
Current assignee: WENDROS CO
Priority date: 1972-02-04
Filing date: 1972-02-04
Publication date: 1974-04-02
Anticipated expiration: 1991-04-02

Abstract

A rotary wing aircraft capable of omnidirectional flight having a plurality of lift devices disposed on support means outboard of a fuselage, each lift device having a plurality of airfoils which rotate about an axis which is perpendicular to the lift vector and substantially parallel to the normal direction of flight, and means for varying the angle of attack of each airfoil in four sectors of the rotation cycle.

Description

Unite States 1 91 1111 3,801,047 DellAquila Apr. 2, 1974 [54] OMNIDIRECTIONAL AIRCRAFT 1,847,222 3/1932 Neubeck..-. 244 6 [75] Inventor: Joseph L. DellAquila, Flushing, 2,386,798 11 1945 Main 244/6 [73] Assignee: Wendros Company, l-licksville, N.Y.

Primary ExaminerDuane A. Reger 411972 Assistant ExaminerJesus D. Sotelo [21] Appl. No.: 223,454

US. Cl.

Int. Cl. 1564c 27/74 Field of Search 244/6-10, 17.11-17.25, 244/19, 21, 2627, 48

References Cited UNITED STATES PATENTS 6/1930 Rystedt 244/9 8/1930 Kertesz 244/6 7] ABSTRACT A rotary wing aircraft capable of omnidirectional flight having a plurality of lift devices disposed on support means outboard of a fuselage, each lift device having a plurality of airfoils which rotate about an axis which is perpendicular to the lift vector and substantially parallel to the normal direction of flight, and means for varying the angle of attack of each airfoil in four sectors of the rotation cycle.

13 Claims, 12 Drawing Figures m m nm 21914 3.801; 047

SHE! 2 0F 4 PATENTEU APR 2 I974 SHEEHHIF4 FIG. 7A

FIG. 7C

FIG. 7B

1 OMNIDIRECTIONAL AIRCRAFT DETAILED DESCRIPTION It is a first object of the present invention to provide a rotary wing aircraft which is not subject to the gyroscopic, transitional and pendulum effects encountered in conventional helicopters.

It is a further object of the present invention to provide a rotary wing aircraft capable of vertical takeoff and landing with excellent omnidirectional maneuverability when hovering or proceeding at low speed but which is free of the limits of speed imposed upon conventional helicopters due to the advance ratio, i.e., a rotary wing aircraft in which increased forward speed is not limited by the effect of the retreating blade.

A further object of the present invention is to provide a rotary wing aircraft which is not subject to the stress reversals encountered in the blades of a conventional helicopter.

Still a further object is to provide an aircraft freed from the size and altitude limitations heretofore imposed on conventional helicopters.

Finally it is an object of the present invention to provide a rotary wing aircraft not subject to the stability inherent in the displacement of the center of gravity and center of lift from the longitudinal axis in a conventional helicopter, the center of gravity and the center of lift in the present aircraft being placed in the longitudinal axis with their placement remaining constant regardless of air speed.

These and other objectives of the present invention will become apparent from the following description, taken in conjunction with the accompanying drawings in which:

.FIGS. lA,-1B and 1C are side elevation, top plan and partial front elevation views, respectively, of the omnidirectional aircraft of the present invention;

FIG. 2 is a plotting of typical angles of attack assumed by a single airfoil in the different sectors ofa single cycle of rotation;

FIG. 3A is a cross-section, partially telescoped, of a portion of the left element and one embodiment of the associated means for varying the angle of attack;

FIG. 3B is an elevation of a variable cam which can be incorporated in the mechanism shown in FIG. 3A;

Referring now to FIGS. 1A, 1B and 1C in greater detail, there is provided a fuselage l1 suspended from an I-I-shaped support means comprising a transverse member 12a and coplanar extensions 12b. Riding on the ends of extensions 12b is at least one pair of lift mechanisms, .two such pairs 13a 13b and 14a 1412, being shown in the embodiment of FIGS. 1A, 1B and 1C.

Each lift mechanism is composed of a hub 15 rotatably mounted on the support means, a plurality of spokes 16 extending radially from hub 15, and an airfoil l7 pivotably mounted at the end of spoke 16. Also provided are power means 18 which are operative to rotate hub 15 and the associated spokes l6 and airfoil 17. While power means 18 is shown in FIG. 1 as being disposed on transverse member 12a over fuselage l 1, it is apparent that one or more appropriate power means can be individually disposed within the support means, i.e., a plurality of motors or engines may be provided so that each lift mechanism is operated independently. Optionally provided are independent propulsion means 19. Such independent means of propulsion can be dispensed within certain embodiments of the invention, it being possible to provide horizontal propulsion, forwards, reverse and sideways, through the use of the lift elements themselves, as discussed below. As is also apparent spokes 16 can be pitched so as to act as conventional propellers.

Airfoils 17 of the lift mechanism rotate about an axis which is substantially parallel to the normal direction of flight and which is perpendicular to the lift vectorof the airfoil. Means are provided so that in the course of a single rotation, each airfoil is pivoted whereby its angle of attack, as measured from the tangent to the circumference of rotation corresponding to the vector of the airfoils angular velocity, varies through thefour sectors of rotation. Referring to FIG. 2, in which the tangential angle of attack is plotted against the four rotational sectors in the course of a single cycle of rotation, it will be seen from line a that the airfoil is positioned at a positive angle of attack of approximately 5 at the midpoint of the first sector rotation, i.e., at 12 oclock; passes to a value of zero in the second and fourth sectors of rotation, i.e., at 9 and 3 oclock; and assumes a value of 5 in the third sector, i.e., at 6 oclock- While the tangential angle of attack is expressed as a negative value in the third sector, the angle of attack relative to the ground is of course positive. Lift is thereby provided at both the top and bottom of the rotational cycle. The actual angle of attack provided will of course depend upon the airfoil cross-section, the an ticipated speed and various other factors and the values represented by line a in FIG. 2 are thus merely one typical sequence of angles of attack providing lift for forward-progress with a given aircraft.

The sectors of the rotational cycle referred to herein are for convenience those defined by any two diameters equiangular to the normal vertical, i.e., the-first sector is that obtained by a radius at a given angle (a) above the horizontal, moving in the direction of rotation through the vertical to angle la). The third sector is that bounded by the opposite angle of the first 7 sector while the second and fourth sectors are the remainder of the circle, each having an angle of 20:. These may all be equal, i.e., but need not b In particular it is often advantageous to make the first and third sectors larger than the second and fourth.

It is not necessary that the angle of attack assumed by the airfoil at the top and bottom of the rotational cycle have the same values and indeed, as shown in line b in FIG. 2, the airfoil can assume a greater angle of attack in the third sector of the rotational cycle than in the first. This is often desirable for purposes of compensating for the downwash on the airfoils in the third sector from those going through the first sector of the cycle of rotation. Thus line b represents a typical cycle, as for hovering action in which the airfoil assumes angle of attack of +1 1 in the first sector of the cycle and an angle'of attack of 1 7 in the third sector of the cycle.

It will be observed that regardless of the angle of attack at the top and that at the bottom of the cycle'of rotation, the airfoils assume an angle of attack of substantially zero in the second and fourth sectors of rotation. The net vector thus provided is one purely of lift, i.e., vertical to the ground. As will be described hereafter, and as is shown by line c in H6. 2, it is possible to shift the entire cycle of rotation of one or more lift mechanisms in the present invention so that the resultant vector for a given lift mechanism is angled from the vertical. Such a shift in the rotational cycle permits a variety of control adjustments, set forth in greater detail below.

Although the theoretical sequential transition from the end of each sector to the others is a step function, it is desirable to design the mechanisms so that the transition from one sector value to the next takes place as rapidly as is feasible, having regard for the stress involved in approaching infinite acceleration,.with the tangential angle of attack remaining constant through substantially all of a given sector.

' A wide variety of means can be employed to effect the variations in the tangential angle of attack of the airfoils in-the course of rotation.'A first mechanism is that shown in FIG. 3A where extending from hub 15, is spoke or radial support 16 with airfoil 17 being pivotably mounted thereon at bearing 21. Connected to airfoil 17 is following rod 22 which rides on cam follower 23. The cam can be either a simple face cam or a positive motion cam. The shape of cam 20 is developed from the base circle having radius r with a'reduced radius r at the top and an increased radius r at the bottom. When-hub 15 is rotated about cam 20, airfoil l7 assumes an angle of attack of substantially zero when cam follower 23 rides on those portions 'of the cam having a radius of r, i.e., in the second and fourth sectors. When cam follower 23 rides upon that portion of the cam having the radius r, airfoil l7 assumes a positive tangential angle of attack whereas when cam follower 23 rides upon that portion of cam 20 having radius r", airfoil l7 assumes a negative tangential angle of attack (relative to the hub but positive relative to the ground).

Since hub.l rotates about cam 20, changes in the angle of attack of airfoil l7 occur automatically in the course ofrotation. The relative effective lift vector provided by this rotation can be easily varied through positioning of the cam. Thus while the alignment of the embodime nts shown in H6. 3A provide vertical lift, a movement of the positioning ofv cam 20 to either-the .right or left results in a corresponding angular change of the relative effective vector provided by the lift mechanism, as previously discussed .in reference to curve c in FIG. 2. 1

In addition we fixed cam, such as cam 20 in'FlG'. 3A, a variable cam can be used whereby the angle of attackachieved in the first and third sectors can be varied.

.Such an embodiment is shown in FIG. 3B in which the the center of rotation, and to maintain that section in a given position upon cessation of motion. Consequently the values r and r" can be varied so as to control, independently, the angles of attack assumed by the airfoil in any given sector, most notably the first and/or third sectors of rotation. The cam is designed so that the values for r remain substantially constant since the airfoils always have an angle of attack of 0 in the second and fourth sectors. While the cam will have only one position in which all the surfaces correspond to an ideal curve, the deviations from the idealin other positions are sufficiently small that they can be ignored and, in any event, are greatly outweighed by the flexibility of control attendant to the ability to adjust the an gles of attack of the airfoils in onesector to any desired value during rotation.

Airfoil 17 can assume a variety of shapes, depending upon the anticipated speed and weight'of the aircraft, speed of revolution, design cruise speed and related design considerations. Generally the considerations are the same encountered in the fabrication of any airfoil. In the course of rotation of the airfoil of course, the surfaces serving as top and bottom surfaces when the airfoil is in the first sector of the rotational cycle reverse their roles when the airfoil is in the third sector. As a result, it is generally desirable to select an airfoil which in cross-section is symmetrically cambered about a curve corresponding to the operating radius of rotation of the airfoil, the chord being dependent on design air speed. Other requirements such as trans-sonic or supersonic flight can also dictate special airfoil design, as well as modifications from normal subsonic operation,

such as limiting lift to only the top sector of rotation.

Generally the airfoil will be pivotably mounted on spoke 16 at approximately the center of gravity since the predominant stress is centrifugal force. Rod 22 can be mounted behind, as in FIG. 3A, or forward of the pivotable mounting (as shown in FIG. 5). It should be observed that in contrast to the blades of a conventional helicopter which encounter stress reversakthe stress on the airfoils of the present aircraft are substantially constant at a given rate of rotation. Pivotable mounting of airfoil 17 at'21 should be designed so as to permit the necessary movement of the airfoil about the longitudinal axis to assume the various angles of attack during rotation without permitting movement of the airfoil away from this axis, i.e., the airfoil should generally remain parallel to the axis of rotation of the hub, which will also be substantially parallel to the normal direction of flight. ln' certain specialized embodiments, some controlled deviation of the airfoil away i from parallel to the axis of rotation is permissible.

FIG. 4 depicts an alternative embodiment in which sectors of the rotationalcycle and several such slip rings are present in any given sector along the length of timer shaft 26, one behind the other. Mounted on the inside channel of the hub for sequential electrical contact with the slip rings are a series of electrical brushes 28. These brushes, are in turn electrically connected through electrical lines 29 to electrical motor 30. Electrical motor 30 is of a type which is reversible g and equipped for rotational control, such as a stepping motor, selsyn motor, or digital feedback motor. Motor 30 is mechanically connected to jack screw 31 which in turn is pivotably connected to airfoil 24 at bearing 32. Airfoil24 is also pivotably mounted at bearing 33 to spoke 34. Appropriate control information in the form of electrical signals is fed through slip rings 27 of timer shaft 26 and contacts 28 to motor 30 which thereby activates jack screw 31, urging airfoil 24 into a new angle of attack.

As in the embodiment shown in FIG. 3A, timer shaft 26 is normally stationary with hub 25 rotating about it. Rotational repositioning of timer shaft 26 a given number of degrees to the right or to the left results in a corresponding shift of the rotational cycle of the airfoils and a resultant change in the lift vector of the particular lift mechanism involved, described in greater detail below.

FIGS. 5 and 6 depict a third embodiment of means operative to vary the angle of attack of the airfoil. In FIG. 5, there is provided a hydraulic timing shaft 35, shown in perspective in greater detail in FIG. 6. Disposed along the circumferential surface of timer shaft 35 are a series of hydraulic ports including pressure port 36 and return

ports

37, 38 and 39.

Return ports

37, 38 and 39 are appropriately disposed over the circumferential surface of shaft 35 across one, two or three of its sectors (corresponding to the sectors of rotation of hub 40) and connected to return line 41 which returns to a reservoir and appropriate pressure maintenance controls (not shown). Pressure channel 42 leads from the pressure maintenance control to pressure port 36 in timing shaft 35. Airfoil 43 is pivotably mounted at bearing 44 and pivotably connected at bearing 45 to piston rod 46 and hydraulic piston 47, the latter operating within hydraulic cylinder 48 into which opens main pressure line 53. A series of hydraulic escape ports and associated hydraulic lines 49, 50, 51 and 52, exit from hydraulic cylinder 48 and, with appropriate valving and conduiting, lead to return

ports

37, 38 and 39 of timing shaft 35 (the inlet in hub 40 from these hydraulic lines to the return ports in shaft 35 and then to return channel 41 lying behind main pressure line 53 and not being shown).

The particular hydraulic system shown in FIG. 5 is but one of many readily apparent to those skilled in the art and is presented solely for purposes ofexemplification. In particular, the system shown in FIG. 5 is one which permits assumption by the airfoil of the angles of attack demonstrated in the rotational cycle shown in FIG. 2. Thus the placement of valves 54 and 55, the placement of the ports within hydraulic cylinder 48 for hydraulic lines 49, 50, 51 and 52, and the spacing of

return ports

37, 38 and 39 on the timing shaft 35 permits the following sequence during each rotational cycle. Upon rotation of hub 40 through the first sector (here shown for purposes of exemplification as 90), main pressure port 36 and return port 39 are open while return ports 37 and 38 are closed, valve 54 also being closed. As a result, piston 47 will be urged above escape ports 49 and 50, and reach hydraulic equilibrium at either port 51 or port 52. If the piston is linked to the airfoil so that hydraulic equilibrium at escape port 50 corresponds to an angle of attack of 0, movement of piston 47 above escape port 50 will urge airfoil 43 to a positive angle of attack. Conventional hydraulic conduit design permits the assumption of several different positive angles of attack. Hence if valve 55 is open, hydraulic equilibrium will be reached at port 51 which may, for example correspond to an angle of attack of +5". If valve 55 is closed, piston 47 will continue upwards and reach hydraulic equilibrium at port 52, thereby urging airfoil 43 to a greater positive angle of attack, as for example +1 1. It is thus possible to achieve different angles of attack in a single given rotational sector, depending upon the particular maneuver of the aircraft. For example, the +5 angle of attack resulting from the opening of valve 55 would be suitable for forward flight while the greater angle of attack of +1 1 obtained when valve 55 is closed would be suitable for hovering. Naturally, the spacing of ports 51 and 52 will depend upon the desired angles of attack to be achieved in a particular sector and the mechanical linkage joining piston 47 and airfoil 43.

As hub 40 rotates through the second sector, main pressure port 36 is closed, as are

return ports

38 and 39. Return port 37, on the other hand, is open and accordingly piston 47, urged by wing forces, descends, reaching hydraulic equilibrium at port 50, the position of zero angle of attack for airfoil 43. As a result, airfoil 43 provides no lift in proceeding through this second sector.

In the third or bottom sector, main pressure port 36 remains closed, as does return port 39, return ports 37 and 38 however both being open. As a result, if valve 54 is closed, piston 47 will reach hydraulic equilibrium at port 49, thereby urging airfoil 43 into a negative angle of attack, as for example 5. If, on the other hand, valve 54 is open, piston 47 will proceed below port 49 and, as a result, urge airfoil 43 into an even greater negative angle of attack, as for example 1 7. Again, the different values for the negative angles of attack assumed by airfoil 43 in the third sector permit the airfoil to work at optimum conditions for separate maneuvers, i.e., 5 for forward motion and l7 for hovering. These values will of course vary depending upon the particular aircraft and the airfoil section. It will also be noted that a greater increment between the two negative values in the bottom sector, as compared with the increment between the two positive values achieved during the top sector, has been incorporated in this example as compensation for downwash which the airfoil encounters in the third sector, as discussed above. This downwash is significantly reduced during forward speed and while such correction can be provided, the airfoil can be positioned at tangential angles of attack of the same magnitude (but opposite sign) during the first and third sectors in normal forward progress.

In proceeding to the fourth sector of rotation, main pressure port 36 and return port 37 are open while

return ports

38 and 39 are closed. The opening of main pressure port 36 and the closing of return port 38 results in the resumption by piston 47 of hydraulic equilibrium at port 50, and as in the case of the second sector, the airfoil achieves an angle of attack of 0.

As in the case of the mechanical and electrical means for varying the angle of attack, the sequence described above for the hydraulic system occurs automatically during rotation of the hub. During rotation, selection of either mode, +5 to 0 to 5 to 0 or +1 1 to 0 to l7 to 0, is made simple through operation of the valves. Hence if valve 54 is closed and valve 55 is open, the airfoils willbe in the first mode whereas if valve 54 is open and valve 55 is closed, the airfoils will be in the second mode.

The various means depicted in FIGS. 3A, 3B, 4, 5 and 6 for varying the angle of attack of each airfoil during a complete rotational cycle are of course presented solely for purposes of exemplification. It is apparent that various mechanical, electrical and hydraulic devices other than those specifically shown, including combinations of these, can be employed. For example, in place of the particular cam shown in FIG. 3, a stepped cam can be employed. Alternatively, a planetary gear train with eccentric cam can be utilized. The particular hydraulic system depicted in FIG. 5 similarly can be replaced by one incorporating a positive variable bypass valve so as to provide greater flexibility in the selection of the angles of attack in the first and third sectors. Quite obviously, combination of these various means can also be employed. Thus for example in FIG. 4, electrical signals from the timing shaft can energize a motor which in turn operates appropriate eccentric cam means which provides the rectilinear motion to effect variations in the angle of attack of the airfoil.

From the above description of the lift mechanism, it is apparent that the amount of overall lift provided can be controlled in a number of fashions. For example, the angle of attack of the airfoil at the first and third sectors of the rotational cycle can be decreased or increased, up to the theoretical limits of the particular airfoil sec tion, thereby decreasing or increasing respectively the amount of lift provided by that particular lift mechanism. Alternatively or in addition, the amount of lift can be changed by varying the speed of revolution of the lift mechanism. Thirdly, the aircraft can be provided with spoiler vanes which can be swung into position beneath the rotating airfoils, either within the circumference of rotation of the airfoils or beneath the entire lift mechanism, so as to reduce the effective lift. Fourthly, the amount of lift can be varied by shifting the cycle of rotation, as for example through partial rotation of the timing shaft, as discussed below.

As has already been noted, the shaft about which the hub rotates is generally stationary, whether the angle of attack is varied by mechanical, electric or hydraulic means. The structure however, should include provisions for displacement of the cycle, as through partial rotation of the shaft, so as to shift the cycle of rotation to the right or left of the vertical. FIG. 7A, FIG. 7B and FIG. 7C are schematic presentations of a few of the variations possible through rotation of the shaft and the resultant vectors. In FIG. 7A, it will be seen that the shafts in each of a pair of lift mechanisms are in their normal vertical alignment with a resultant vertical lift. In FIG. 7B, the shaft about which the righthand lift mechanism rotates has been rotated a few degrees to the right. Having assumed this position, the cycle of rotationfin terms of the lift vector of that particular lift mechanism is also shifted, i.e., each sector is shifted clockwise the number of degrees the shaft is rotated. Since the lefthand lift mechanism has not been shifted, the relative resulting lift provided by this pair of lift mechanisms is a vector of the two individual components, the direction of the vector being to the right of the vertical. In FIG. 7C, the shaft about which the righthand lift mechanism rotates has been shifted counterclockwise while the shaft about which the lefthand lift mechanism rotates has been shifted clockwise an equal number of degrees. As a result, while both lift mechanisms have relative lifts transverse to the vertical, their individual vectors are in opposition so as to provide a relative resultant vector which is again vertical but of a lesser magnitude than that achieved in the alignment shown in FIG. 7A. Thus without altering the rate of revolution of the lift mechanisms or the angles of attack, the relative resultant lift of the aircraft can be decreased by rotating the shafts, as shown in progressing from FIG. 7A directly to FIG. 7C, or conversely can be increased by returning the shafts to their normal alignment, as would be the case in proceeding directly from FIG. 7C to FIG. 7A. Quite obviously, shifts in the relative resultant vectors can also be achieved through changes in the speed of rotation and in the angle of attack of the individual airfoils during this rotation, as discussed above.

A further feature of this displacement of the shaft is the great facility with which autorotation can be achieved. Thus, if in the course of flight a power failure were to occur, rotation of the shaft so that it is from its normal vertical position reverses the first and third sectors in the cycle of rotation. With such a reversal, the airfoil thus assumes a negative tangential angle of attack in the first sector and a positive tangential angle of attack in the third sector. The result is that the descent of the aircraft under the normal influence of gravity will effect autorotation of the airfoil with a glider effect reducing the rate of descent.

Use of a variable cam, such as that shown in FIG. 3B, permits autorotation without rotation of the cam. For example if, overlapping section 56a is moved upwards so that r is greater than r and section 56 is retracted so that r" is less than r, the airfoil will achieve a negative angle of attack in the first sector and a positive angle of attack in the third sector, and autorotation will occur.

As a result of the variety of means through which the lift can be varied in normal operation, actual control of the aircraft, either while hovering, rising, descending, proceeding in forward or reverse motion or in combinations, can be effected through any one of a number of ways or any combination thereof.

Utilizing an embodiment such as that shown in FIG. 1 in which there are two pairs of lift elements, roll, pitch and yaw of the aircraft can be readily achieved through the creation of lift differentials. If, for example,

the two lift mechanisms on one side of the aircraft are adjusted so as to provide increased lift, through any of the means discussed above, as compared with the lift provided by the two lift mechanisms on the other side of the aircraft, a roll maneuver will result. On the other hand, if a differential lift is established between the front pair of lift mechanisms as compared with the rear pair of lift mechanisms, a pitch maneuver will result. Combined pitch and roll maneuvers can also be executed through the establishment of a lift differential between diagonal lift mechanisms. Rotation of the cycle of a lift mechanism, as through rotational repositioning of the shaft, introduces a sideward component into the vector of that mechanism. With the cycle of one mechanism so shifted, or those of diagonal mechanisms shifted in opposing directions, a yaw maneuver results. Shifting the cycle of two mechanisms on one side while increasing their lift, as through increasing speed of rotation or angle of attack, so that their lift is the same as that of the mechanisms on the other side results in a sideward motion without a change in altitude.

Hence simply by varying the lift and the lift vector of the individual lift mechanisms, roll, pitch and yaw maneuvers, singly or in combination, as well as ascending, descending and sideward motion can be achieved. As will be seen below, forward and reverse motion can also be achieved in this fashion.

In addition to the foregoing techniques, the aircraft can be provided with conventional control surfaces such as a rudder and elevator. Moreover, the transverse portions of the support means can itself assume an airfoil cross-section and be equipped with ailerons.

Horizontal forward and reverse propulsion of the aircraft can also assume a variety of forms. The aircraft can be equipped with conventional propulsion means in the fuselage, such as a jet engine or a piston or turbine engine driving conventional or reversible propellers. Such conventional propulsion means can in the alternative, or in addition, be provided in the longitudinal portions of the support means. Thus the support means can bear conventional or reversible propellers which rotate about an axis substantially parallel to the axis of rotation of the lift mechanism. Optionally, the spokes or radial supports of the lift mechanism can themselves be designed with an appropriate propeller cross-section and pitch, which can be variable, so as to provide not only support for the airfoils but also forward propulsion. It can be noted that while the embodiments depicted herein utilize three spokes, any number more than one can be employed, with a like number of airfoils, symmetrically placed and balanced about the circumference of the hub. It should be noted that when the spokes are provided with pitch, a second means of autorotation is provided. Hence the pitch of the propellers will cause the entire lift mechanism to revolve as the aircraft proceeds forward though windmilling, thereby producing lift from the rotating airfoils. Alternatively the airfoils are reversed and their rotation drives the non-reversed propellers, giving forward thrust.

In addition to the utilization of conventional propulsion means, both forward and reverse propulsion can be provided by the lift mechanisms themselves. in the simplest maneuver, the aircraft is merely pitched, as described above, and held in that alignment, the horizontal component of the lift vector causing forward or reverse motion. Alternatively, if the support means is adapted for rotational positioning along a horizontal axis perpendicular to the normal direction flight, the entire support means and associated lift means can be tilted relative to the fuselage, either forward or backward, thereby introducing a horizontal component to the lift vector. Hence in FIGS. 1A, 1B and 1C, transverse member 12a of the support can be positionally rotated so. that extensions 12b are angled to the direction of flight and thereby introduce a forward component into the effective lift provided by the lift mechanisms while keeping the fuselage level.

It is apparent that the various specific embodiments described herewith may be varied and modified with out departing from the spirit of the present invention since such embodiments have been presented solely for the purposes of exemplification and not for limitation of the invention, the invention being defined solely by the appended claims.

What is claimed is:

10 l. A rotary wing aircraft comprising a. support means, b. at least two pair of lift mechanisms disposed on said support means, each of said lift mechanisms comprising 1. a hub rotatably mounted on said support means for rotation about an axis substantially parallel to the normal direction of forward flight;

2. a plurality of spokes extending radially from said hub;

3. a plurality of airfoils disposed on said spokes lengthwardly along lines parallel to and equidistant from the axis of rotation of said hub and pivotably mounted so as to permit variation in their tangential angle of attack;

4. means operable to vary the angle of attack of the airfoils of each lift mechanism independently of the other lift mechanisms during a complete rotational cycle from a value of substantially zero in a second and fourth sector to a value substantially other than zero in a first and third sector, said means including a timing shaft mechanism about which said hub rotates operable to change the angle of attack of each airfoil associated with that hub in passing from one sector of the rotational cycle to the next sector of the cycle, said shaft being rotatably positionable from a first position in which the effective lift vector of the lift mechanism is vertical, to other positions in which the rotational cycle is shifted proportionally to the arc of said rotational positioning, whereby the effective lift vector of that lift mechanism is angled to the vertical;

0. power means operable to rotate each of said lift mechanisms independently of the others, and

d. a fuselage disposed on said support means between said lift mechanisms.

2. A rotary wing aircraft as defined in claim 1 wherein said timing shaft mechanism is rotationally positionable from said first vertical position for autorotation.

3. A rotary wing aircarft as defined in claim 1 wherein said timing shaft mechanism includes angle adjusting means operable to selectively change the angle of attack assumed by an airfoil passing through a given sector of the rotational cycle. I

4. A rotary wing aircraft according to claim 3 wherein said angle adjusting means is a variable cam.

5. A rotary wing aircraft as defined in claim 1 wherein the angle of attack to be assumed by each airfoil in each sector of the rotational cycle is conveyed hydraulically from said timing shaft.

6. A rotary wing aircraft as defined in claim 1 wherein the angle of attack to be assumed by each airfoil in each sector of the rotational cycle is conveyed electrically from said timing shaft.

7-. A rotary wing aircraft as defined in claim 1 wherein the angle of attack to be assumed by each airfoil in each sector of the rotational cycle is conveyed mechanically from said timing shaft.

8. A rotary wing aircraft as defined in claim 7 wherein said timing shaft mechanism comprises a cam operable to define the angle of attack of each airfoil and further including cam follower means linked to said airfoil for varying the angle of attack during rotation of the hub about said cam.

1 1 9. A rotary wing aircraft as defined in claim 8 wherein the cam is a variable cam.

10. A rotary wing aircraft comprising a. an =H-shaped support comprising a transverse member and two coplanar extensions thereof, b. two pair of lift mechanisms, each of said lift mechanisms disposed on a terminal portion of said extensions, each of said lift mechanisms comprising 1. a hub rotatably mounted on said extensions for rotation about an axis parallel to the longitudinal axis of said extensions and substantially parallel to the normal direction of forward flight;

2. at least three spokes extending radially from each of said hubs;

3. an airfoil lengthwardly disposed on each of said spokes along a line parallel to and equidistant from the axis of rotation of said hub and pivotably mounted so as to permit variation in its tangential angle of attack; I g

4. means operable to vary the angle of attack of the airfoils of each lift mechanism independently of the other lift mechanisms during a complete rotational cycle from a value of substantially zero in a second and fourth sector to a value substantially other than zero in a first and third sector, said means including i. a normally stationary but rotatably positionable timing cam shaft about which said hub rotates,

said cam shaft being operable to initiate said variations in the angle of attack of the airfoil from one sector to another and by rotational positioning to a position other than its normal position to shift the rotational cycle, said cam being adjustable for selectively changing the angle of attack to be assumed by the airfoil when in any given sector of the rotational cycle; and

ii. cam following means linked to the airfoil for varying the angle of attack during rotation of the hub about the cam;

c. variable speed power means operable to rotate each said lift mechanism independently of the others, and 1 d. a fuselage pivotably disposed on said transverse member of the support between said lift mechanisms for positional adjustment through the axis of the transverse member of the plane of said support, relative to fuselage.

11. A rotary wing aircraft as defined in claim 1 including independent means of horizontal propulsion.

12. A rotary wing aircraft as defined in claim 11 wherein said independent means of propulsion are disposed on the fuselage.

13. A rotary wing aircraft as defined in claim 11 wherein said independent means of propulsion are disposed on said extensions of said support.

Claims

1. A rotary wing aircraft comprising a. support means, b. at least two pair of lift mechanisms disposed on said support means, each of said lift mechanisms comprising 1. a hub rotatably mounted on said support means for rotation about an axis substantially parallel to the normal direction of forward flight; 2. a plurality of spokes extending radially from said hub; 3. a plurality of airfoils disposed on said spokes lengthwardly along lines parallel to and equidistant from the axis of rotation of said hub and pivotably mounted so as to permit variation in their tangential angle of attack; 4. means operable to vary the angle of attack of the airfoils of each lift mechanism independently of the other lift mechanisms during a complete rotational cycle from a value of substantially zero in a second and fourth sector to a value substantially other than zero in a first and third sector, said means including a timing shaft mechanism about which said hub rotates operable to change the angle of attack of each airfoil associated with that hub in passing from one sector of the rotational cycle to the next sector of the cycle, said shaft being rotatably positionable from a first position in which the effective lift vector of the lift mechanism is vertical, to other positions in which the rotational cycle is shifted proportionally to the arc of said rotational positioning, whereby the effective lift vector of that lift mechanism is angled to the vertical; c. power means operable to rotate each of said lift mechanisms independently of the others, and d. a fuselage disposed on said support means between said lift mechanisms.

2. a plurality of spokes extending radially from said hub;

2. at least three spokes extending radially from each of said hubs;

2. A rotary wing aircraft as defined in claim 1 wherein said timing shaft mechanism is rotationally positionable 180* from said first vertical position for autorotation.

3. A rotary wing aircarft as defined in claim 1 wherein said timing shaft mechanism includes angle adjusting means operable to selectively change the angle of attack assumed by an airfoil passing through a given sector of the rotational cycle.

3. an airfoil lengthwardly disposed on each of said spokes along a line parallel to and equidistant from the axis of rotation of said hub and pivotably mounted so as to permit variation in its tangential angle of attack;

4. means operable to vary the angle of attack of the airfoils of each lift mechanism independently of the other lift mechanisms during a complete rotational cycle from a value of substantially zero in a second and fourth sector to a value substantially other than zero in a first and third sector, said means including i. a normally stationary but rotatably positionable timing cam shaft about which said hub rotates, said cam shaft being operable to initiate said variations in the angle of attack of the airfoil from one sector to another and by rotational positioning to a position other than its normal position to shift the rotational cycle, said cam being adjustable for selectively changing the angle of attack to be assumed by the airfoil when in any given sector of the rotational cycle; and ii. cam following means linked to the airfoil for varying the angle of attack during rotation of the hub about the cam; c. variable speed power means operable to rotate each said lift mechanism independently of the others, and d. a fuselage pivotably disposed on said transverse member of the support between said lift mechanisms for positional adjustment through the axis of the transverse member of the plane of said support, relative to fuselage.

4. means operable to vary the angle of attack of the airfoils of each lift mechanism independently of the other lift mechanisms during a complete rotational cycle from a value of substantially zero in a second and fourth sector to a value substantially other than zero in a first and third sector, said means including a timing shaft mechanism about which said hub rotates operable to change the angle of attack of each airfoil associated with that hub in passing from one sector of the rotational cycle to the next sector of the cycle, said shaft being rotatably positionable from a first position in which the effective lift vector of the lift mechanism is vertical, to other positions in which the rotational cycle is shifted proportionally to the arc of said rotational positioning, whereby the effective lift vector of that lift mechanism is angled to the vertical; c. power means operable to rotate each of said lift mechanisms independently of the others, and d. a fuselage disposed on said support means between said lift mechanisms.

7. A rotary wing aircraft as defined in claim 1 wherein the angle of attack to be assumed by each airfoil in each sector of the rotational cycle is conveYed mechanically from said timing shaft.

9. A rotary wing aircraft as defined in claim 8 wherein the cam is a variable cam.

10. A rotary wing aircraft comprising a. an H-shaped support comprising a transverse member and two coplanar extensions thereof, b. two pair of lift mechanisms, each of said lift mechanisms disposed on a terminal portion of said extensions, each of said lift mechanisms comprising