BACKGROUND OF THE INVENTION There is a long history of aerial vehicles which attain flight through the movement of the wings. Of course, the most successful derivation of this concept is the helicopter. Modern helicopters and conventional aircraft have comparable characteristics of speed, lifting capacity and passenger comfort. These characteristics of the helicopter result from the rotary wing design wherein the wings or blades rotate in a plane parallel with the longitudinal axis of the fuselage.

In attaining the level of performance of current models, the helicopter has become a very complex machine requiring highly trained pilots. One of the most notable features of the helicopter is the balancing of dynamic rotational forces to attain controllable flight. The torque generated by the rotary wing acting against the fuselage must be managed by the pilot to attain straight and level flight. In addition, the pilot must simultaneously manipulate other flight controls similar to an airplane. Further, if the helicopter loses the function of the vertical tail rotor or ducted fan, which provides critical anti-rotational force, controlled flight is impossible.

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Ornithopters also use a wing drive for flight. In contrast to the rotary wing of the helicopter, the ornithopter has reciprocating wings which move in a plane normal to the longitudinal axis of the fuselage. The ornithopter eliminates the complexity required for overcoming dynamic rotational forces of flight at the expense of flight speed and incidence of reciprocal vibration. However, the lifting capacity of the ornithopter can be substantial and flight operation is less complex than a helicopter.

Ornithopters can be useful in specialized tasks requiring slow moving observation or lifting or remote flight found in construction, forestry, oil and gas industry, and the military.

DESCRIPTION OF THE PRIOR ART U. S. Patent No. 6,206, 324 to Smith discloses an ornithopter with multiple sets of computer controlled wings which may be programmed to reciprocate in various combinations. The angle of attack of the wings is controlled throughout each reciprocation to provide optimal lift and minimal drag.

The Michelson patent, U. S. Patent No. 6,082, 671, is an attempt to teach the concept of a mechanical insect.

The wings are twisted, to optimize lift, during reciprocation by rotation of the wing spar.

A toy ornithopter is disclosed in U. S. Patent No.

4,155, 195. The two sets of wings of the device are mounted on the fuselage in a vertically overlapping design. The sets of wings are reciprocated by crank arms oriented at 90 degrees to each other and powered by a rubber band. The sets of wings reciprocate out of phase with each other in that as one set moves downwardly the other set is moving upwardly. The flight path is preset by adjusting the empennage before flight.

What the prior art lacks is an ornithopter with a simple drive system for the wings and a flexible fuselage that can control direction of flight.

SUMMARY OF THE INVENTION Accordingly, it is an objective of the instant invention to teach an ornithopter having vertically moving wings for lift and thrust with a bending fuselage for flight path control.

It is a further objective of the instant invention to teach the use of a pivoting power beam linked to a power source and the wings for reciprocating the wings.

It is yet another objective of the instant invention to teach damping vertical vibration by counterbalancing the forces generated by the wings.

It is a still further objective of the invention to teach flight path control by moving the center of gravity.

It is another objective to teach the controllability of the vehicle at slow speeds, well below stall speed of fixed wing aircraft and below the speed at which a conventional empennage is effective, by flapping wings for lift and thrust and by moving the center of gravity in flight.

It is another objective of the invention to teach that the force required to support the lift of the front set of wings is counterbalanced by the force of the aft set of wings.

Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.

BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a perspective of the ornithopter of this invention showing relative direction of movement of the wings in phantom lines; FIG. 2A is a side view, partially in section, of the forward fuselage and wing mounts in one phase of reciprocation; FIG. 2B is a side view, partially in section, of the forward fuselage in the phase of flight shown in FIG. 1; FIG. 3 is a perspective of the invention showing deflection of the aft fuselage in phantom lines; FIG. 4A is a plan view, partially in section, of the control system for deflecting the aft fuselage; FIG. 4B is a plan view, partially in section, of the control system deflecting the aft fuselage for a right turn; FIG., 4C is a plan view, partially in section, of the control system deflecting the aft fuselage for a left turn; FIG. 5 is a plan view of a bracket for the control system; FIG. 6 is a perspective of the ornithopter of this invention with an empennage; and FIG. 7 is a perspective of a wing panel of this invention.

DETAILED DESCRIPTION OF THE INVENTION The ornithopter 10 has a fuselage 11, wings 12 and landing gear 13, as shown in FIG. s 1,3, and 6. The fuselage 11 has a rigid forward portion 14 and a flexible aft portion 15. A passenger compartment (not shown) and/or a load carrying apparatus (not shown) would be attached to the rigid forward fuselage 14 in a conventional manner. A power source 16, by way of

illustration, is shown in FIG. s 2A and 2B, as mounted within the forward fuselage 14. However, the power source may be mounted in other locations on the vehicle. Also, the power source is shown as a generator but any type of motor may be used, including fuel burning reciprocating engines, turbines, fuel cells, batteries or others.

The power source 16 drives a fly wheel 17 through a belt 18 and cooperating pulleys 19 and 20. Of course, the belt could be a chain and the pulleys could be sprockets, as a matter of choice. Also, a drive shaft could be used in place of the belt, with bevel gears, to drive the fly wheel 17.

The fly wheel 17 has an eccentrically mounted pin 21 connected to a drive link 22. Journal 23 permits drive link 22 to rotate around the pin 21 during rotation of the fly wheel. Another journal 24 is in the other end of the drive link 22. Journal 24 rotatably connects the drive link to the power beam 25. This arrangement results in reciprocation of the power beam in response to the rotation of the fly wheel.

As an alternative (not shown), the power beam could be reciprocated by solenoids acting on the end (s) of the beam.

The power beam 25 is mounted on the rigid forward fuselage by a pin 26 located intermediate the length of the beam. As the drive link 22 reciprocates, the power beam 25 pivots about pin 26. As can be seen in FIG. s 2A and 2B, the drive link 22 attaches by journal 24 to the power beam 25 nearer one end to provide the reciprocation of the beam. A pin 27 is located on power beam 25 near the journal 24. The pin fits into a rotating journal on connecting link 28. Connecting link 28 rotatably connects power beam 25 and wing mount 29 through journal 30. This link smoothly transfers the reciprocating force of power beam 25 to the front set of wings 31.

The other end of power beam 25 includes pin 32 journaled into rear connecting link 33 for rotational movement. The rear connecting link 33 is rotatably connected to journal 34 on rear wing mount 35 by pin 36.

Rear wings 35 are connected to the wing mount 35. As power beam 25 pivots about pin 26, the front set of wings move in one direction while the rear set of wings move in the opposite direction. The opposite movement of the sets of wings counterbalances the reciprocating forces on the fuselage and provides smooth flight. As can be seen by a comparison of FIG. s 2A and 2B, the distance of the throw of the ends of power beam 25 is equal. However, the additional linkage on the front wings dampens the transition of the change of direction of the wings.

Stationary shaft 37 is mounted on the forward fuselage 14 between the forward set of wings and extends vertically normal to the longitudinal axis of the fuselage. The wing mount 29 slidably engages the shaft 37 and moves along its length during reciprocation of the wings. The wing mount 29 carries journals 38 and 39 which rotatably connect to wing spars 40 and 41 of forward wings 42 and 43.

Rear stationary shaft 44 is mounted on the forward fuselage between the rear set of wings and extends vertically normal to the longitudinal axis of the fuselage. The wing mount 35 slidably engages the shaft 44 and moves along its length during reciprocation of the wings. The wing mount 44 carries journals 45 and 46 which rotatably connect to wing spars 47 and 48 of the rear wings 49 and 50.

The lift force of the forward set of wings supported by pin 27 of beam 25 is counterbalanced by the lift force of the rear wings at pin 32 of beam 25.

Both the rear and front sets of wings have a rotating connections 38,39, 45 and 46 to the wing mounts 29 and

35, respectively, which also smooth out the reciprocating vibration forces.

In this manner, the pivoting of the power beam 25 drives the wing mounts 29 and 35, in opposite directions, translating the vertical movement to the flapping of the forward wings 42 and 43 with the rear wings 49 and 50.

In FIG. 3, the deflection of the flexible rear fuselage 15 is illustrated as a lateral movement of the free end of the fuselage in the yaw axis of the vehicle.

In the slow flight regime of the ornithopter, a shift in the center of gravity coupled with asymmetrical increased drag will change the flight path. The deflection of the flexible fuselage is not severe enough to cause permanent bending or structural damage of the rear fuselage. The rear fuselage will tend to return to the longitudinal axis upon relief of the control input. The rear fuselage is made up of a central longeron 51 made of a material with a desired moment of elasticity and strength. The longeron is connected at one end 52 to the rigid fuselage 14 and the free end 53 is connected to the surrounding control elements 54,55, 56 and 57.

As shown in FIG. s 4A, 4B, and 4C, the control bar 58 is connected on a plate 59 mounted on the forward fuselage 14. The bar 58 has a center pin 60 which forms a rotatable connection with an aperture in the plate 59.

Control input may be applied through the center pin 60 or through the ends of the control bar 58. In the Fig. s, the bar 58 is rotatably connected at 61 and 62 to the lateral control elements 54 and 57, respectively, for deflection in the yaw axis. Control elements 55 and 56 may be in the form of longerons or may be rotatably connected to another control bar (not shown) oriented at 90 degrees to the control bar 58 to operate the control elements in the pitch axis. The control elements may be in the form of control cables or control rods. To maintain spatial

orientation of the control elements and the longeron 51, a series of brackets 63 are attached along the length of the longeron 51. The brackets have apertures through which the control elements pass.

In the modification shown in FIG. 6, the aft fuselage is provided with an empennage 64 with aerodynamic control surfaces 65 in the yaw axis and 66 in the pitch axis for added stability and control of the ornithopter at higher speeds. The control surfaces 65 may include movable rudders (not shown) and/or fixed trim tabs on the trailing edges. The control surfaces 66 may include movable elevators (not shown) and/or fixed trim tabs on the trailing surfaces.

In order to more closely mimic the efficiency of a bird's wing, the ornithopter has control of the angle of attack and the twist of the wings through each cycle.

Each of the wings 12 of the ornithopter 10 has a flexible wing surface 67 in the nature of a sail. The wings surface 67 has a leading edge 68, a foot 69, and a trailing edge 70. The leading edge and the trailing edge intersect at the tip 71 opposite the foot 69. The leading edge of the wing surface is attached to the wing spars of the of the wings 12. As shown in FIG. 7, the wings surface 67 is attached to wing spar 41 of the front set of wings. The foot 69 of the wing surface forms the wing root and includes a batten 72 extending from the leading edge 68 to the trailing edge 70 for stiffening the wing surface material. To provide more shaping to the wing surface, battens 73, 74 and 75 are spaced from the foot to the tip. The battens may be made from any light weight material that has the requisite flexibility and strength to reinforce and hold the desired shape of the wing surface.

To provide adjustability of the twist in the wings a down haul 76 is attached to the foot of the wing surface

and extends parallel to the spar. Added tension on the down haul 76 tends to flatten the wing surface longitudinally. Such a control input is related to an increase in the relative wind speed. An vang 77 is attached to the batten 72 near the trailing edge of the wing surface and extends to the spar. By increasing the tension on the vang 77, the twist of the wing surface is flattened laterally. These control inputs could be set before flight or operated by flight controls during flight. In any event, the angle of attack of the wings and the drag may be adjusted by adjusting the twist of the wings.

It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement of parts herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and drawings.