HK1159041A - A flying machine comprising twin contra-rotating vertical axis propellers - Google Patents

Description

Aircraft comprising a pair of contra-rotating vertical axis propellers

Technical Field

The invention relates to an aircraft comprising a pair of contra-rotating vertical axis propellers located below a load to be carried.

Background

Aircraft have been proposed which include a flying platform on which a user stands and beneath which propellers are mounted to generate lift to lift the platform from the ground. The platform includes peripheral armrests for grasping by a user who adjusts his weight to control tilt, thereby controlling the direction in which the platform moves. Such an aircraft is proposed in U.S. patent 2953321 to Arthurson et al. Charles Simelmann has also been proposed in the fourth and fifth decades of the twentieth century.

Although the underlying theory of a flying platform with such an early assumption has been established, commercial practices and a more manageable version have never been realized.

Disclosure of Invention

The present application stems from a number of issues related to work addressing real-world impracticalities and the previously proposed very basic flying platform.

According to a first aspect of the invention, there is provided an aircraft comprising at least one electric motor and two vertical axis contra-rotating propellers, the blades of which are arranged to rotate the propellers by means of the electric motor to generate lift, the aircraft being equipped with a seat and a handle mounted on the aircraft above the propellers at a position radially inwards of the periphery of the propellers.

Preferably, the propeller is arranged such that: the characteristics of the propellers may be varied for any difference in airflow into each propeller so that, in use, each propeller produces substantially the same lift.

Preferably, the pitch of the propeller blades may be varied.

Preferably, the aircraft comprises two electric motors.

Preferably, the two motors are connected to a single drive means which is effective to transmit output drive from the motors to the propeller.

Preferably, the motors are each connected to the drive means by a respective one-way clutch, effectively enabling one motor to drive the drive means without the need for the other motor.

Preferably, the handle is laterally spaced from the rotational axis of the propeller in one direction and the seat is laterally spaced from the rotational axis of the propeller in an opposite direction.

Preferably, movement of at least part of the handle is effective to control the yaw of the aircraft.

Preferably, rotation of the handle relative to the vehicle controls the yaw of the vehicle.

In one embodiment, the aircraft includes a tail propeller, and the handlebars are effective to control the tail propeller to control the yaw of the aircraft.

Preferably, the handle is effective to control the rotational speed of the tail propeller.

In another embodiment, the handle is effective to change the characteristics of the contra-rotating propellers, thereby causing a torque reaction to urge the aircraft to yaw.

Preferably, the handlebars control the difference between the collective pitch of the blades of each contra-rotating propeller to control the yaw of the aircraft.

Preferably, the handlebars control the collective pitch of the blades of only one propeller to control the yaw of the aircraft.

The handlebars may alternatively or additionally control the relative speed of rotation of the propellers to control the yaw of the aircraft.

Preferably, the aircraft comprises at least one throttle lever, the movement of which controls the speed of the electric motor.

Preferably, the handlebars comprise a twist grip, the rotation of which controls the collective pitch of the blades of the at least one propeller and thus the lift generated.

Preferably, the aircraft includes a collective pitch mechanism effective to vary the collective pitch of the blades of the propellers, the mechanism including a swash plate connected to the propeller blades, movement of the swash plate relative to the propeller blades rotating the propeller blades about their longitudinal axes to vary the pitch of the propeller blades.

Preferably, the swashplate is arranged to move linearly in a direction parallel to the axis of rotation of the propeller, this linear movement being converted into a rotary motion of the blades by means of a linkage connecting the swashplate to the blades.

Preferably, each propeller is associated with its respective swash plate.

In one embodiment, there is one transfer swash plate to transfer the motion of one swash plate to the other swash plate.

Preferably, an actuator is provided to influence the movement of one swash plate, which is transmitted to the other swash plate by means of the transmission swash plate, so that the collective pitch of the blades of the two propellers is controlled simultaneously by one actuator.

In another embodiment, the movement of each swashplate is controlled by a respective actuator, such that the collective pitch of the blades of one propeller is controlled independently of the collective pitch of the blades of the other propeller.

Preferably, the propeller is surrounded by a peripheral skirt.

Preferably the skirt includes a plurality of vertically spaced apart lifting eyes, the gaps between the lifting eyes acting as ducts to provide air to the propeller in use.

Preferably, the suspension ring has an aerofoil cross section.

Preferably, the base of the aircraft includes a plurality of skids on which the aircraft is supported when not in flight.

Preferably, the base of the aircraft includes a centrally mounted hub to assist in movement of the aircraft when not in flight.

Preferably the hub comprises a ball rotatably mounted in a slot in the base of the aircraft.

According to a second aspect of the present invention there is provided an aircraft comprising at least one electric motor and two vertically-counter-rotating propellers, the propeller blades being arranged to rotate the propellers by means of the electric motor to generate lift, a handle movably mounted on the aircraft above the propellers, movement of the handle relative to the aircraft in use effecting yaw control of the aircraft.

Preferably, rotation of the handle relative to the chassis of the aircraft affects yaw control of the aircraft in use.

In one embodiment, the aircraft includes a tail propeller, and the handlebars are used to control the tail propeller to control the yaw of the aircraft.

Preferably, the handle is used to control the rotational speed of the tail propeller.

In another embodiment, the handle is used to change the characteristics of the contra-rotating propellers to reduce torque reaction, thereby causing the aircraft to yaw.

Preferably, the handle alters the difference between the collective pitch of each counter-rotating propeller blade to reduce torque reaction.

Preferably, the handlebars control the collective pitch of only one propeller blade to control the yaw of the aircraft.

The handlebars may alternatively or additionally control the relative rotational speed of the propellers to control the yaw of the aircraft.

Preferably, the handlebars comprise a twist grip, the rotation of which controls the collective pitch of the blades of the at least one propeller, thereby controlling the lift generated.

Preferably, the aircraft includes a collective pitch mechanism for varying the collective pitch of the blades of the propellers, the mechanism comprising a swash plate connected to the propeller blades, movement of the swash plate relative to the propeller blades rotating the propeller blades about their longitudinal axes to vary the pitch of the propeller blades.

Preferably, the swash plate is linearly moved in a direction parallel to the rotational axis of the propeller, and this linear movement is converted into rotational movement of the blades by a linkage connecting the swash plate and the blades.

Preferably, each propeller is associated with a respective swash plate.

In one embodiment, there is one transfer swash plate to transfer the motion of one swash plate to the other swash plate.

Preferably, an actuator is provided to influence the movement of one swash plate, which is transmitted to the other swash plate by means of the transmission swash plate, so that the collective pitch of the blades of the two propellers is controlled simultaneously by one actuator.

In another embodiment, the movement of each swashplate is controlled by a respective actuator, such that the collective pitch of the blades of one propeller is controlled independently of the collective pitch of the blades of the other propeller.

According to a third aspect of the present invention there is provided an aircraft comprising at least one electric motor and two vertical axis contra-rotating propellers, the blades of the propellers being arranged to generate lift when the propellers are rotated by the electric motor, handlebars being mounted on the aircraft above the propellers, the aircraft further comprising a collective pitch mechanism for collectively controlling the pitch of the blades of the propellers, the collective pitch mechanism being controlled by the handlebars.

Preferably, the handlebars comprise a twist grip, the rotation of which controls the collective pitch of the blades of the at least one propeller, thereby controlling the lift generated.

Preferably, the collective pitch mechanism comprises a swashplate connected to the propeller blades, movement of the swashplate relative to the propeller blades rotating the propeller blades about their longitudinal axes to vary the pitch of the propeller blades.

Preferably, the swash plate is linearly moved in a direction parallel to the rotational axis of the propeller, and this linear movement is converted into rotational movement of the blades by a linkage connecting the swash plate and the blades.

Preferably, each propeller is associated with a respective swash plate.

In one embodiment, there is one transfer swash plate to transfer the motion of one swash plate to the other swash plate.

Preferably, an actuator is provided to influence the movement of one swash plate, which is transmitted to the other swash plate by means of the transmission swash plate, so that the collective pitch of the blades of the two propellers is controlled simultaneously by one actuator.

In another embodiment, the movement of each swashplate is controlled by a respective actuator, such that the collective pitch of the blades of one propeller is controlled independently of the collective pitch of the blades of the other propeller.

According to a fourth aspect of the present invention there is provided an aircraft comprising at least one electric motor and two vertical axis contra-rotating propellers, the blades of the propellers being arranged to generate lift when the propellers are rotated by the electric motor. The aircraft also includes a yaw control mechanism for changing the characteristics of at least one propeller relative to the other propellers to reduce torque reaction, effectively causing the aircraft to yaw.

Preferably, the yaw control mechanism controls the difference between the collective pitch of the blades of each contra-rotating propeller to reduce torque reaction.

Preferably, the yaw control mechanism controls the collective pitch of only one propeller to control the yaw of the aircraft.

The yaw control mechanism may alternatively or additionally control the relative rotational speed of the propellers to control the yaw of the aircraft.

Preferably, the yaw control mechanism comprises a collective pitch mechanism for varying the collective pitch of the blades of the propeller, the mechanism comprising a swashplate connected to the propeller blades, movement of the swashplate relative to the propeller blades rotating the propeller blades about their longitudinal axes to vary the pitch of the propeller blades.

Preferably, the swash plate is linearly moved in a direction parallel to the rotational axis of the propeller, and this linear movement is converted into rotational movement of the blades by a linkage connecting the swash plate and the blades.

Preferably, each propeller is associated with a respective swash plate.

Preferably, the movement of each swashplate is controlled by a respective actuator, such that the collective pitch of the blades of one propeller is controlled independently of the collective pitch of the blades of the other propeller.

According to a fifth aspect of the invention, there is provided an aircraft comprising at least one electric motor and two vertical-axis contra-rotating propellers, the blades of which are arranged to generate lift when the propellers are rotated by the electric motor, the aircraft being equipped with a seat and a handle mounted on the aircraft above the propellers, and a hub projecting below the propellers and below the lowest part of the aircraft, the hub partially supporting the aircraft in a tilted orientation when the aircraft is at rest, the user being able to control the aircraft during takeoff by partially supporting the aircraft by the hub and by the lift generated by the propellers with the hub in a non-tilted orientation.

According to a sixth aspect of the present invention there is provided an aircraft comprising at least one electric motor and two vertical axis contra-rotating propellers, the blades of the propellers being arranged to generate lift when the propellers are rotated by the motor, a load-bearing zone being provided above the propellers, each propeller being provided with a respective blade pitch control mechanism, the aircraft further comprising a controller, the blade pitch control mechanisms and the controller being arranged such that the pitch of the blades of one propeller can be controlled independently of the pitch of the blades of the other propeller.

Preferably, the blade pitch control mechanism and controller are arranged such that each of the collective and cyclic pitch of the blades of one propeller is independently controllable relative to each of the collective and cyclic pitch of the blades of the other propeller.

Preferably, the at least one blade pitch control mechanism is actuated by a servo mechanism controlled by the controller.

Most preferably, each blade pitch control mechanism is controlled by a respective servo mechanism.

Preferably, each blade pitch control mechanism is provided by its own set of servomechanisms, one for each propeller blade.

Preferably, each propeller is driven by a respective drive shaft, the drive shafts being coaxial, at least one of the drive shafts being hollow such that at least one blade pitch control mechanism is housed in that drive shaft.

According to a seventh aspect of the present invention there is provided an aircraft comprising at least one electric motor and two vertically-counter-rotating propellers, the blades of the propellers being arranged to generate lift when the propellers are rotated by the electric motor, a payload bay being mounted above the propellers.

Preferably, the stowage compartment is elongate and extends along a longitudinal axis of the aircraft, the width of the compartment being less than the width of the aircraft.

The stowage compartment may include a stretcher for carrying the injured person.

The propulsion fan assembly comprises a rearwardly directed propeller mounted for rotation about the axis of rotation of the propeller perpendicular to the vertical axis and arranged such that, in use, the rearwardly directed propeller generates additional thrust.

At least one movably mounted wing is provided, the angle of inclination of which can be adjusted relative to the aircraft.

Preferably, the moveably mounted wing is mounted for rotation about a horizontal axis extending transversely across the aircraft.

Preferably, a plurality of movable airfoils are provided.

Preferably, the first set of movable wings is disposed forward of the aircraft and the second set is rearward of the aircraft.

According to an eighth aspect of the present invention there is provided an aircraft comprising at least one electric motor and two vertically-axis contra-rotating propellers, the blades of the propellers being arranged to generate lift when the propellers are rotated by the electric motor, a load-bearing zone above the propellers, a controller comprising a plurality of gyroscopes for generating signals indicative of attitude of the aircraft, the controller being arranged to process the signals and to control the aircraft to remain in a predetermined attitude.

Other aspects of the invention may include any combination of the features or limitations mentioned herein.

Drawings

The invention may be implemented in numerous ways and will now be described with reference to an embodiment of the drawings. Wherein:

FIG. 1 illustrates a perspective view of an aircraft from the front in accordance with the present invention;

FIG. 2 illustrates a perspective view of the aircraft shown in FIG. 1 from the rear;

FIG. 3 is a schematic view of the aircraft shown in FIGS. 1 and 2 from the front;

FIG. 4 is a side view of the aircraft of FIGS. 1-3;

FIG. 5 is a top and front perspective view of the aircraft of FIGS. 1-4, with the airframe and controls removed for clarity;

FIG. 6 is a more detailed perspective view of the aircraft shown in FIGS. 1-5 from the top and forward, with portions of the airframe of the aircraft cut away;

FIG. 7 illustrates a side cross-sectional view of a collective pitch mechanism used by the aircraft according to the present invention;

FIG. 8 illustrates a side cross-sectional view of another collective pitch mechanism used by the aircraft according to the present invention;

FIG. 9 illustrates a plan view of another embodiment of an aircraft according to the present invention;

FIG. 10 is a perspective view of the aircraft of FIG. 9 from a front side;

FIG. 11 shows a front view of the aircraft of FIGS. 9 and 10;

figure 12 shows a side view of the aircraft of figures 9 and 10;

FIG. 13 is a perspective view of the forward side of the aircraft of FIGS. 9-12, with portions of the aircraft in an open position;

FIG. 14 is a plan view of a further embodiment according to the present invention;

FIG. 15 is a perspective view of a forward side of the aircraft of FIG. 14;

FIG. 16 illustrates a front view of the aircraft of FIGS. 14 and 15;

FIG. 17 illustrates a side view of the aircraft of FIGS. 14-16;

FIG. 18 illustrates a side cutaway view of yet another collective pitch used by the aircraft according to the present disclosure;

FIG. 19 illustrates a side view of the improved aircraft with portions of the aircraft removed for clarity and other portions of the aircraft in a first state, according to the present invention;

FIG. 20 illustrates a front view of the improved aircraft of FIG. 19;

FIG. 21 is a plan view of the improved aircraft of FIGS. 19 and 20;

FIG. 22 is a side view of the improved aircraft of FIGS. 19-21, with portions of the aircraft in a second configuration;

FIG. 23 is a side elevational view of the improved aircraft of FIGS. 19-22 in a square configuration with portions of the aircraft in a first position;

FIG. 24 is a view corresponding to FIG. 23, except with portions of the aircraft in a second state;

FIG. 25 is a side view of another improved aircraft according to the present invention, with portions of the aircraft removed for clarity; the other part of the aircraft is in the first state;

FIG. 26 is a front elevational view of the alternative improved aircraft of FIG. 25;

FIG. 27 is a plan view of the alternative improved aircraft of FIGS. 25 and 26; and

figure 28 is a side view of the alternative improved aircraft of figures 25-27 with portions of the aircraft in a second configuration.

Detailed Description

Referring to fig. 1-6, an aircraft 1 includes a chassis 3 on the underside of which are mounted two propellers 5, 7 of opposite vertical axis rotation, the propellers sharing a common axis of rotation 8. The propellers 5, 7 are driven by two electric motors 9 through the same drive mechanism 10, the electric motors 9 being mounted on the chassis 3 above the propellers 5, 7 and spaced longitudinally along the chassis 3. The machine body is mounted on top of the chassis 3, above the propellers 5, 7, and comprises an aerodynamic front piece 13, a seat 15 behind the front piece 13, and a tail piece 17 behind the seat 15, the tail piece 17 being equipped with a ducted tail propeller 19 in this embodiment. The handle 21 is movably mounted on the chassis 3 between the seat 15 and the front piece 13, in this embodiment rotatably mounted. The user of the aircraft thus straddles the electric motor 9 and the drive mechanism 10 with his legs, sitting substantially centrally on top of the propeller, in a driving position very similar to that of a motorcycle.

The chassis 3 comprises two parallel main chassis struts 23 which extend longitudinally aft from the front of the aircraft 1. An annular skirt 25 surrounds the propellers 5, 7 and is mounted at the end of the chassis brace 23. The skirt 25 comprises a plurality of vertically spaced rings 27 having an airfoil cross-section. The rings 27 are held in spaced apart positions by a plurality of vertical spacer struts 29 to define air ventilation ducts between each pair of rings 27.

The base of the skirt 25 is provided with three equispaced runners 31, 32. The two lateral runners 31 extend forward at an angle of about 45 degrees along the longitudinal axis of the aircraft 1 from the propeller shaft 8 to the skirt 25. The tail runner 32 extends rearwardly from the propeller shaft 8 in a direction coaxial with the longitudinal axis of the aircraft 1.

The lowermost face of each runner 31, 32 is curved and a central hub or swivel mounting ball 33 is mounted on the propeller shaft 8 at the intersection of the runners 31, 32. Thus, when the aircraft 1 is placed on the ground, it will have an inclined orientation, leaning backwards and to one side, resting on the ball 33, the tail runner 32 and one of the side runners 31. The aircraft 1 is lifted on the ground, the runners 31, 32 are lifted off the ground and the aircraft can rotate around it while being supported only on the balls 33.

The body is also circular in plan with its periphery coinciding with the top edge 34 of the skirt 24. The nose piece 13, seat 15 and tail piece 17 form a unitary body extending longitudinally from the front to the rear of the aircraft, mounted on top of the chassis 23. The seat 15 and the handle 21 are spaced apart along the longitudinal axis of the chassis 3 and are located radially inwardly of the periphery of the propellers 5, 7. Curved spokes 34 extend radially outwardly from the main body unit to the top edge of the skirt 25. The footrest 36 is disposed adjacent to the seat 15.

In this embodiment, the aircraft 1 comprises two electric motors 9 longitudinally spaced along the chassis strut 23, one on either side of the axis of rotation 8 of the propellers 5, 7. In this embodiment, each electric motor 9 comprises a four-stroke rotary gasoline engine, each comprising a respective air ventilation duct 37 for taking in air from an intake 38 formed in the nose piece 13 of the aircraft 1, each air ventilation duct comprising a respective exhaust duct and a silencer 39, which exits through the tail piece 17 of the aircraft 1. The speed of each motor 9 is controlled by a respective throttle lever (not shown in the figures), which are arranged side by side below the front seat handle 21. Both are provided with RPM readings for the pilot's weight. Once set at this particular RPM, the throttle lever is not used during normal flight.

Each motor 9 includes a respective output shaft 41 connected to a respective sprag or other one-way clutch 43. The output shaft of each wedge clutch 43 is input to a common drive mechanism 10.

The drive mechanism 10 includes a transmission housing 45 in which two vertical, coaxial propeller shafts 47, 49 are mounted, the outer shaft 47 accommodating the upper part of the inner shaft 49. The upper end of each propeller shaft 47, 49 is provided with a respective 45-degree bevel propeller gear 51, 53. The lower ends of the propeller shafts 47, 49 are connected to the upper and lower propellers 5, 7, respectively.

The bevel gears 51, 53 are vertically spaced apart and driven by a smaller bevel gear 55 mounted in the transmission housing 45 at the end of the output shaft 44 of the wedge clutch. A smaller bevel gear 55 is located intermediate the two bevel gears 51, 53 so that the lower bevel gear 51 is driven by rotation of the sprag clutch output shaft 44 to rotate the outer propeller shaft 47 and the upper propeller 5 in a first direction. The upper bevel gear 53 is driven by rotation of the wedge clutch output shaft 44 to rotate the inner propeller shaft 49 and the lower propeller 7 in the opposite direction to the upper propeller 5.

The electric motor 9 and the drive mechanism 10 are arranged to drive the propellers 5, 7 in counter-rotation which eliminates or minimises any torque reaction that would otherwise cause the aircraft 1 to yaw about the propeller axis 8.

The wedge clutch 43 allows one motor 9 to drive the propellers 5, 7 without the other motor 9 or requiring one motor 9 producing less torque than the other, the clutch 43 being associated with a non-functional or reduced torque, the motor 9 allowing the clutch output shaft 44 to rotate relative to the output shaft 41 of the motor 9.

The radially innermost ends of each blade 5A of the upper propeller 5 are mounted on respective pairs of spaced mounting discs 51. Each pair of disks 51 is mounted on a hub 53 at the lower end of the outboard propeller shaft 47 by two radially spaced ball and socket connections 55. The attachment member 55 is provided in such a manner that: the blades 5A and the hub 53 rotate about the propeller axis 8 and each blade 5A also rotates about its own longitudinal axis 57, the longitudinal axis 57 being an axis perpendicular to the propeller axis of rotation 8, so that the pitch of the blades 5A can be varied.

Likewise, the radially innermost ends of each of the blades 7A of the lower propeller 7 are mounted on respective pairs of spaced mounting discs 71. Each pair of disks 71 is mounted on a hub 73 at the lower end of the inner propeller shaft 49 by two radially spaced ball and socket connections 75. The connector 75 is arranged such that: the blades 7A and the hub 73 rotate about the propeller axis 8 and each blade 7A also rotates about its own longitudinal axis 77, the longitudinal axis 77 being an axis perpendicular to the propeller axis of rotation 8, so that the pitch of the blades 7A can be varied.

Fig. 7 and 8 show two examples of collective pitch mechanisms that collectively control the pitch of the blades 5A, 7A of each propeller 5, 7.

Referring to fig. 7, a collective pitch mechanism 81 is shown in which the pitch of the blades 5A, 7A of the upper and lower propellers 5, 7 is controlled simultaneously by a single actuator.

The collective pitch mechanism 81 includes a non-rotating control shaft 83 that passes coaxially through the center of the inner propeller shaft 49, the upper end of the control shaft 83 projecting from the top of the transmission housing 45, and the lower end of the control shaft 83 projecting below the lowest hub 73 of the propeller 7.

The upper end of the control shaft 83 is connected to an actuator 85, which in this example comprises a linear servo actuator. The actuator 85 is controlled by a twist grip control 86 at one end of the handlebar 21.

A lower swash plate 87 is rotatably installed at the lower end of the control shaft 83. The lower swash plate 87 is connected to the lower mounting plate 71 of each pair of plates 71 by a respective linkage 89 at a location spaced from the longitudinal axis of the blade 7A in question. The linkage 89 transmits the rotational movement of the lower propeller 7 to the lower swash plate 87, so that the lower swash plate 87 is rotatably driven relative to the control shaft 83 by the lower propeller 7.

The upper mounting plate 71 of each blade 7A is connected to the swash plate 91 by a respective transfer linkage 93. The swash plate 91 is rotatably driven with the inner propeller shaft 49 and is mounted on a bushing 94, and the bushing 94 axially slides up and down along the inner propeller shaft 49.

A bushing 94 connects the transfer swash plate 91 to an upper swash plate 97, the upper swash plate 97 being connected by a linkage 99 to the lower mounting plate 51 of each pair of plates 51 of the upper propeller 5. The upper swash plate 97 is rotatably mounted on a boss 94 rotating with the upper propeller 5, i.e., in the opposite direction of the lower propeller 7 and the lower swash plate 87, 91.

In use, the user actuates the actuator 85 by twisting the twist grip 86 on the handle 21. This causes the control shaft 83 to move upwardly relative to the gearbox housing 54 and the propellers 5, 7. Pushing down swashplate 87 upward, this upward linear motion is translated by linkage 89 into clockwise rotation of blade 7A about its longitudinal axis 77.

The upward movement of the lower swash plate 87 is transmitted to the swash plate 91 through the transmission linkage 93, which also pushes the swash plate 91 and the boss 94 upward along the inner propeller shaft 49. The boss 94 transmits this vertical upward movement to the upper swash plate 97 which rotates together with the upper propeller 5. The upward linear motion of the upper swash plate 97 relative to the upper propeller 5 is converted by the linkage 99 into a counterclockwise rotation of the blades 5A about their longitudinal axes 57.

Thus, by twisting the twist grip 86 of the handle, the collective pitch of the blades 5A, 7A of the upper and lower propellers 5, 7 is simultaneously changed, about the longitudinal axis of the blades 5A, 7A, in one direction, explaining the opposite rotation of the propellers 5, 7, i.e. the clockwise rotation of the lower blade 7A and the anticlockwise rotation of the upper blade 5A. Twist handle 86 acts as a collective pitch control, controlling the ascent or descent of aircraft 1 in use.

In this embodiment, the pitch of the propeller blades 5A, 7A is not used to control the yaw of the aircraft 1. Alternatively, characteristics of the tail rotor 19 such as the pitch or rotational speed of the blades are used to control yaw. Control is achieved by rotating the handle 21 relative to the chassis 3 in the direction required for yaw of the aircraft. Rotation of the handle 21 triggers an actuator which, in turn, adjusts the pitch or rotational speed of the tail rotor 19.

Referring to fig. 8, an alternative collective pitch mechanism 101 is shown, wherein the distance of the blades 5A, 7A of the upper and lower propellers 5, 7 is independently controlled. The alternative collective pitch mechanism 101 functions as a yaw control mechanism.

This mechanism 101 is similar to the mechanism 91 except that the transfer and upper swash plates 91, 97 are omitted. The lower swash plate 87 maintains and controls the collective pitch of the blades 7A of the lower propeller 7 as described above.

In this embodiment, the collective pitch of the upper propeller blades 5A is controlled by a yaw swashplate 103, which swashplate 103 is connected to the upper mounting plate 51 of the blades 5A of the upper propeller 5 by respective linkages 105. The yaw swashplate 103 is rotatably mounted on a bushing 107, and the bushing 107 slides axially up and down along the outboard propeller shaft 47. The top of the sleeve 107 is connected to a linear servo actuator 109, and the actuator 109 is mounted on the lower portion 111 of the transmission housing 45.

The actuator 109 moves the bushing 107 up and down slidingly along the outboard propeller shaft 47, thereby moving the yaw swashplate 103 closer to or away from the upper propeller 5. The linear motion of the yaw swashplate 103 relative to the upper propeller 5 is translated through linkage 105 into a counterclockwise rotation of the upper propeller blades 5A about their longitudinal axes 57.

The lower and yaw swashplates 87, 103 and their associated actuators 85, 109 enable the collective pitch of the blades 5A, 7A of the upper and lower propellers 5, 7 to be adjusted independently.

By simultaneously adjusting the collective pitch of the lower propeller blades 5A and the collective pitch of the upper propeller blades 7A, the ascent and descent of the aircraft 1 can be controlled as described above.

However, by adjusting the upper propeller blades 5A independently of the lower propeller blades 7A, the torque reaction produced by the oppositely rotating propellers 5, 7 is altered, thereby controlling the yaw of the aircraft 1.

In this embodiment, the pitch of the lower propeller blades 7A is kept constant while the aircraft is controlled for yaw, the extent of which is controlled only by varying the collective pitch of the blades 5A of the upper propeller.

The actuator 109 controlling the pitch of the blades 5A of the upper propeller is triggered by the twist handle 86 on the handlebar 21 and by the rotation of the handlebar 21 itself. The actuator 85 controlling the pitch of the lower propeller blade 5A is only activated by the twist handle 86 on the handlebar 21.

Thus, if the user wishes to lift, he twists the twist handle 86, which twist handle 86 actuates the two actuators 85, 109, simultaneously changing the collective pitch of the blades 5A, 7A of the upper and lower propellers.

If the user wishes to yaw in one direction, the user holds the twist handle 86 in a fixed position and then turns the handle 21 in the desired direction. This activates only the upper actuator 109 to increase the pitch of the blades 5A of the upper propeller, thereby increasing the torque reaction in a given direction, yawing the aircraft 1 clockwise. If the handle 21 is rotated in the reverse direction, the upper actuator 109 is activated to reduce the pitch of the blades 5A of the upper propeller, thereby reducing the torque reaction that causes the aircraft 1 to yaw counterclockwise. If the handlebars 21 are held in the straight-ahead position, the actuators 85, 109 cause the collective pitch of the blades 5A, 7A of the upper and lower propellers to be the same, so that there is no torque reaction and, therefore, the aircraft 1 is not yawing.

In this embodiment, the tail propeller 19 is not required and is negligible.

In each of the above embodiments, some additional control of the ascent and descent of the aircraft is provided by increasing or decreasing the speed of the motor 9 using the throttle lever.

The directional control of the aircraft 1 is obtained by means of a motor sensation, i.e. the adjustment of the weight distribution of the user relative to the aircraft 1. Moving the aircraft 1 forward and the user forward and moving the aircraft 1 backward, the user tilts backward. In flight, the user may also maneuver the aircraft 1 by tilting to one side or the other, such control usually being coordinated with the use of the handlebars 21 to control the yaw of the aircraft 1.

In flight in a given direction, the airflow passes through the duct in the skirt 25 above the annulus 27 of the airfoil. This simplifies the airflow over the propellers 5, 7 and generates lift that increases the speed and efficiency of the aircraft 1.

The pitch of the blades 5A, 7A of the upper and lower propellers differs somewhat, taking into account that in practice the upper and lower propellers 7 move air faster in use.

On the ground, it can be surrounded by rotating the aircraft 1 using the center ball 33. The ball 33 may be made of a low friction material to allow multidirectional movement of the aircraft 1 in a recess in the base of the aircraft 1, either on the ground or rotatably mounted.

The hub and tail runner 32 in the form of a ball 33 is mounted: when placed, the aircraft 1 is in an inclined orientation so that the rear is tilted to assist in takeoff, with the weight of the aircraft adjusted by the user so that the tail runner 32 is off the ground before the entire aircraft 1. This provides the user with feedback of the appropriate weight distribution before the aircraft 1 takes off. The central ball 33 is mounted lower than the peripheral skirt 25. During a preliminary takeoff operation, using for example 60% thrust from the propellers 5, 7, the pilot will learn to balance on the central sphere 33 without the peripheral skirt 25 coming into contact with the ground. When the overall balance is reached, it is time for the aircraft 1 to be in a non-inclined orientation by means of the centre sphere 33 and the lift support from the propellers 5, 7, and then the collective pitch is increased in order to start take-off.

It is envisaged that the body 11 is made of carbon fibre and the skirt 25, ring 27 and chassis 3 are made of aluminium. The skirt 25 is approximately 0.25m deep and 2m in diameter. It will be appreciated that any other suitable materials and dimensions may be used.

A harness may be provided to enable the user to secure himself to the aircraft 1. A parachute mechanism may also be provided, such as stored within the nose piece 13 of the aircraft 2 so as to be mounted just forward of the handle 21.

The actuators 85, 109 and the actual motor speed and the tail rotor 19 blade pitch/speed may be controlled by a remotely controllable autopilot, so that no direct mechanical connection is required between the handlebars 21, the twist grip 86, the throttle lever and the moving parts of the aircraft 1.

In the described embodiment, the electric motor 9 is an internal combustion engine, but may be replaced by any other suitable power source, such as an electric or hydrogen powered motor. It is desirable to use an internal combustion engine that is two or four stroke and that is compatible with gasoline, diesel or biofuel and that may incorporate a supercharged air intake system (e.g., supercharger or turbocharger).

It is envisaged that other means of controlling the yaw of the aircraft 1 may additionally or alternatively be provided by adjusting the relative rotational speed of either propeller 5, 7. For example by means of a disc actuator of the upper propeller 7.

Referring again to fig. 9-13, the aircraft 12 of the alternative embodiment further includes a chassis under which are mounted two propellers 5, 7 of opposite vertical axis, the propellers sharing the same axis of rotation and being driven by two motors passing through the same drive mechanism, the motors being mounted on the chassis above the propellers 5, 7 and spaced longitudinally along the chassis.

In this embodiment, the body mounted on top of the chassis above the propellers 5, 7 comprises a load compartment 123 which can be closed by a hinged or removable cover 125.

The load-bearing compartment is elongated and has a longitudinal axis that coincides with the longitudinal axis of the aircraft, and the compartment 123 has a length that extends along a substantial portion of the length of the aircraft, but has a relatively narrow width such that the sides of the compartment 123 are remote from the side edges of the aircraft.

Referring to fig. 14-17, an aircraft 131 of yet another embodiment has features similar to the aircraft 121 described above with reference to fig. 9-12. However, the improved carrying cabin can carry one person. Thus, a cutout 133 is provided at one end of the hatch cover 125 to expose at least the head of a person. The cutout may be covered by a vented transparent cover (not shown).

In the embodiment of 121, 131, the tail propellers are omitted and the yaw of the vehicle 121, 131 is controlled by varying the rotational effect produced by each propeller 5, 7.

Furthermore, it is contemplated that the flight of the aircraft 121, 131 may be remotely controlled using a suitable radio or GPS-based controller.

Referring to fig. 18, the improved pitch control mechanism 140 can independently control the collective and cyclic pitch of each set of blades 5A, 7A through independent servos.

As in the previous embodiments of fig. 7 and 8, each electric motor 9 comprises a respective output shaft 41 (which may be the output shaft of an intermediate gearbox (not shown)) connected to a respective sprag or other one-way clutch 43. The output shaft 44 of each wedge clutch 43 is input to a common modified drive mechanism.

The drive mechanism includes an upper transmission housing 145 in which are mounted two vertical, coaxial propeller shafts 147, 149, the outer shaft 147 housing the majority of the inner shaft 149. The upper end of each propeller shaft 147, 149 is provided with a respective 45-degree helical bevel gear 151, 153. The lower ends of the propeller shafts 47, 49 are connected to the upper or lower propellers 5, 7, respectively.

The bevel gears 151, 153 are vertically spaced apart and are driven by a smaller bevel gear 155 mounted at the end of the wedge clutch output shaft 44 in the transmission housing 145. A smaller bevel gear 155 is intermediate the two bevel gears 151, 153 so that rotation of the sprag clutch output shaft 44 drives the lower bevel gear 151 to rotate the outer propeller shaft 147 and the upper propeller 5 in a first direction. The upper bevel gear 153 is driven by rotation of the wedge clutch output shaft 44, thereby rotating the inner propeller shaft 149 and the lower propeller 7 in the opposite direction to the upper propeller 5.

The radially innermost end of each blade of the upper propeller 5 is mounted on a respective bracket 151. Each bracket 151 is mounted to a hub 153 at the lower end of the outboard propeller shaft 147 by two radially spaced ball and socket connections 155.

Likewise, the radially innermost end of each blade 7A of the lower propeller 7 is mounted on a respective bracket 171. Each bracket 171 is mounted on a hub 173 at the lower end of the inner propeller shaft 149 by two radially spaced ball and socket connections 175.

The outer shaft 147 has a relatively wide diameter and is hollow to accommodate the inner shaft 149 and swashplate and control linkage that controls the collective and cyclic pitch of the lower rotating blades 7A.

The outer shaft 147 is rotatably mounted in the transmission housing 145 by suitable bearings. The lower end of the outer shaft 147 protrudes from the lower portion of the transmission case 145, and a connecting member 151 is mounted on the exposed portion of the outer shaft 147.

The upper swash plate mechanism 181 is installed outside the lower portion of the transmission case 145, and includes a lower swash plate 183 rotating together with the upper propeller 5 and connected to the connection 151 of each upper blade 5A through a linkage 185. The lower swash plate 183 is engaged with the upper swash plate 187 and is pushed up and down by the upper swash plate 187, and the upper swash plate 187 is prevented from rotating by a hinge arm 189.

The upper swash plate 189 is connected to a pair of push/pull control servos 193 mounted on the outside of the transmission case 145 through an upper connecting arm 191.

The servo 193 can be controlled to move the swash plate 187 up and down, which motion is converted to the rotating lower swash plate 183 to adjust, either collectively or periodically, the pitch of the blades 7A of the lower propeller 7.

The inner shaft 149 is rotatably mounted within the outer shaft 147 by suitable bearings/seals. The inner shaft 149 is also hollow. The lower end of the inner shaft 149 projects from the lower end of the outer shaft 147, and the lower rotor hub 173 is mounted on the projecting end of the inner shaft 149. Each seat 171 is connected to a respective pitch control arm 195, the control arm 195 extending through a wall of a lower portion of the inner shaft 149.

Each pitch control arm 195 is connected to a respective lower control rod 197, and rod 197 extends upwardly within shaft 149, through two axially spaced rod supports 199, 201 to a lower swashplate 203 of a lower swashplate mechanism 202. The lower swash plate 203 is rotatably mounted on a spherical bearing 205, the bearing 205 is slidably mounted on a stationary swash plate support rod 207, and the top of the support rod 207 is fixed to a transmission housing cover 209.

The lower swash plate 203 is engaged with the upper swash plate 211, and the upper swash plate 211 is non-rotatably mounted on the support rod 207.

The upper swash plate 211 is connected to an upper control rod 213, and the control rod 213 extends upwardly within the inner shaft 149 through control rod supports 215 to respective linear push/pull servos 219 mounted on the end caps 209.

Actuation of servo 219 moves upper control rod 213, and control rod 213 slides upper swashplate 211 up and down support rod 207. The movement of the upper swash plate 211 is transmitted to the lower swash plate 203. The movement of lower swash plate 203 is transferred to pitch control arm 195 through lower control rod 197 to adjust the angle of each blade 7A of lower propeller 7.

In this way, the collective and cyclic pitch of the blades 5A of the upper propeller 5 can be controlled independently of the collective and cyclic pitch of the blades 7A of the lower propeller 7. The use of servos to effect these controls makes it possible to use an electronic controller (wired or wireless) to control the servos, so that no direct mechanical connection is required to operate the servos and the pitch of the blades of the upper and lower propellers 5, 7.

Two sets (one for the lower propeller 5 and one for the upper propeller 7) of three independent servomechanisms 193, 219 and two swash plate mechanisms 181, 202 allow independent and different collective and cyclic pitch of the propellers 5, 7.

The different collective pitch controls desired provide the aircraft with precise yaw/heading control. By controlling the pitch of the lower propeller 7 to be different from the pitch of the upper propeller 5, a moment effect is created in one direction, causing the vehicle to rotate, i.e. causing the vehicle to yaw. This can be accomplished by similarly controlling the upper propeller servo 193 so that the swash plates 183, 187 remain at the same angle, but move up and down the drive shafts 147, 149. Each upper blade 5A rotates in its seat 151 about a set angle and controls the lower propeller servo 219 to rotate each lower blade 7A about a different angle in its seat 171.

Different cyclic pitch control is obtained by controlling unequal movement of the upper propeller servo 193 such that the swash plates 183, 187 are inclined relative to the drive shafts 147, 149 such that the angle of rotation of each blade 5A, 7A within the respective seat 151, 171 is different, the angle of rotation depending on the rotational position of the blade 5A, 7A.

Although independent control of the vanes 5A, 7A is possible, it should be clear that the swash plates 183, 187, 203, 211 may be controlled to move the upper and lower vanes 5A, 7A identically for standard control inputs, unless the aircraft heading needs to be changed.

In this embodiment, the central hub 33 is rotatably mounted to the base of the inner shaft 149 using suitable bearings, including pneumatic, shock-absorbing hemispherical ball bearings.

Referring now to fig. 19-24, the improved aircraft 200 is provided with fore-aft elongated adjustable wings 221 that replace the fore-aft portion of the fixed airfoil ring 27 of the aircraft 1 previously described. The adjustable wings 221 each comprise a longer wing mounted on a fixed airfoil ring 27, which rotates about a horizontal axis at the center of pressure 223 of each wing 21, respectively.

Each of the front and rear set of wings 221 is controlled by a suitable mechanical or electromechanical control mechanism. It is envisioned that each set of wings may be attached to a respective control arm that is moved by a linear push/pull servo.

Each set of wings 221 is movable between a neutral position as shown in fig. 19-23 and an inclined position as shown in fig. 22-24.

In the neutral position, the front and rear set of wings 211 direct air in a direction generally indicated by arrow 223, i.e., in a direction parallel to the longitudinal axis of the aircraft. This neutral position is used for hovering or low speed flight.

However, when additional lift is required, the front and rear set of wings 221 are moved to an inclined position to direct air in a direction generally indicated by arrow 225, i.e., in a direction oblique to the longitudinal axis of the aircraft.

The movable wing can generate additional lift if desired.

Of course, the front and rear set of wings 221 can be independently controlled to allow independent movement of the front or rear set of wings. This makes it possible to adjust the generated lift very precisely. It is contemplated that the angle of the airfoil 221 may be automatically controlled in response to input by an operator to an aircraft requiring more or less lift.

Referring now to fig. 25-28, the rear of another improved aircraft 230 is provided with a rear propulsion fan assembly 231 comprising an impeller tube 233 in which is rotatably mounted a propeller impeller 235 having an axis of rotation parallel to the longitudinal axis of the aircraft, i.e. perpendicular to the axis of rotation of the propellers 5, 7.

The propeller impeller 235 is driven by an impeller drive shaft 239 through an impeller transmission 237, the impeller drive shaft 239 extending rearwardly from an auxiliary gearbox 241 in the centre of the aircraft 230. The impeller gearing 237 may include, for example, a gear or belt connection between the impeller 235 and the drive shaft 237. A clutch 243 is mounted between the auxiliary gearbox 241 and the drive shaft 239. The auxiliary gearbox 241 is driven by the main gearbox 10 of the aircraft 230.

The propulsion fan assembly 231 is used to generate additional forward thrust when needed. This may be simple when additional forward speed is required, or may assist in other ways, such as quickly raising the height or changing direction.

The propulsor fan assemblies 231 of the movable airfoils 221 may be controlled simultaneously and automatically such that the blades 5, 7, airfoils 221, and propulsor fan assemblies 231 combine to deliver a desired combination of forward thrust, lift, and direction.

It is envisioned that any of the features discussed above may be combined as desired and are not limited to the particular embodiments discussed. For example, the propulsion fan assembly may be mounted on the aircraft rather than on a movable wing.

It is envisaged that the aircraft described above may be equipped with a plurality of seats. Spaced apart laterally along the aircraft or arranged longitudinally.

The speed and pitch of the propellers 5, 7, servos 193 and 219, movable wing 221 and propulsion fan assembly 231 may be controlled mechanically or electronically by suitable wired or wireless controllers, if desired.

The aircraft may be automatically controlled, i.e. without the need for a pilot on board the aircraft. Automatic control may be achieved by using gyroscopes mounted on the aircraft which detect movement of the aircraft in a given direction and send a signal to the controller to vary the speed and pitch of the propellers 5, 7, the servos 193 and 219, the movable wing 221 and the propulsion fan assembly 231 to generate a force to resist the detected movement.

A plurality of piezoelectric electronic gyroscopes are incorporated into a controller that controls a flight control servo of the aircraft. Each gyroscope and each servo maintains the aircraft in a particular predetermined attitude in terms of yaw, angle of attack, and roll, unless commanded by an additional pilot or controller. The gyro stabilization system prevents air turbulence or aircraft weight distribution from being affected by attitude of the aircraft in flight. It also allows the aircraft to be piloted by pilots with very low levels of dexterity, since the aircraft is somewhat self-controlling in its attitude, i.e., independent of pilot input. The controller may be configured to: if the pilot relinquishes control of the aircraft entirely, the controller is set to a neutral position such as a stationary hover position.

A plurality of accelerators are also incorporated into the controller that controls the flight control servos. Each accelerator evaluates high motion, side slip, and snake motion. In addition, it allows the aircraft to remain in a stationary position even in high winds, suspended by the controller, and prevents the aircraft from rushing to land too quickly.

All parameters of the gyroscopes and accelerators are programmed into the controller to accommodate the pilot's level or the appropriate automatic control needs. Different programs may be used for different pilots or users.

The gyroscope control system can also maintain stability in three directions.

The controller may be effective to control the speed and pitch of the propellers 5, 7, the servos 193, 219, the movable wing 221 and at least one of the propulsion fan assembly 231 to move the vehicle in a change of direction, wherein the centre of gravity is moved back under the vehicle by sensing the descent of the vehicle by the gyroscope.

It is envisaged that the cyclic pitch of both the upper and lower propellers 5, 7 is changed at a gap of, for example, 0.06 seconds, if required. For example, if a gust of wind blows the aircraft slightly to the right, the gyroscope senses this and sends a signal to the controller controlling the cyclic pitch to increase the pitch, while approaching the right hand side of the aircraft, increasing only the lift on that side of the aircraft and re-flattening the aircraft. It is envisaged that thousands of signals per minute are sent from the controller to the servomechanism to adjust the pitch, thereby keeping the aircraft in optimum condition at all times. The accelerator operates in the same manner unless the aircraft is controlled by the controller to remain in the last perceived position, rather than in a particular attitude.

In another alternative embodiment of the aircraft, the cyclic and collective pitch of the blades 5A of the upper propeller 5 and the cyclic and collective pitch of the blades 7A of the lower propeller 7 may be controlled using only three servos. The pitch of the upper set of blades 5A is not controlled independently of the pitch of the lower set of blades 7A. Arranged in this way, the yaw of the aircraft can be controlled by means of an airflow adjustment mechanism comprising means for adjusting the airflow into and/or out of the propellers 5, 7.

This mechanism may comprise two sets of adjustable guide vanes, both sets being mounted above the propellers 5, 7, one set facing forward of the aircraft and the other set facing rearward of the aircraft. Two sets of devices were installed as follows: one blade per set on each side of the longitudinal axis of the aircraft. For the movement, each blade is mounted around a main horizontal axis, which makes it possible to adjust the direction of some of the air flow through the propellers 5, 7. The airflow may be regulated by guide vanes on either side of the longitudinal axis of the aircraft, causing the aircraft to turn right or left.

The air flow regulating means includes any means for changing the direction of the air flow, including vanes in the form of airfoils, flaps or various open tubes.

The air flow adjustment means may be located at any suitable position relative to the propellers 5, 7. Such positions include, for example, above the top propeller 5, below the lower propeller 7 or in between the propellers 5, 7.

Claims (76)

1. An aircraft comprising at least one electric motor and two vertical axis contra-rotating propellers, the blades of the propellers being arranged to generate lift when the propellers are rotated by the electric motor, the aircraft being equipped with a seat and a handle mounted on the aircraft above the propellers at a position radially inward of the periphery of the propellers.

2. The machine of claim 1 wherein the propellers are arranged such that the characteristics of the propellers can be varied in response to any difference in airflow into each propeller such that, in use, each propeller is caused to generate substantially the same lift.

3. The machine of claim 2, wherein preferably the pitch of the propeller blades can be varied.

4. The aircraft according to any one of the preceding claims, characterized in that it comprises two electric motors.

5. The machine of claim 4 wherein the two motors are connected to a single drive means for transmitting the output drive of the motors to the propeller.

6. The machine of claim 5 wherein each motor is connected to the drive by a respective one-way clutch, the one-way clutch allowing one motor to drive the drive but not the other motor.

7. The machine of any one of the preceding claims wherein the handle is spaced laterally from the axis of rotation of the propeller in one direction and the seat is spaced laterally from the axis of rotation of the propeller in the opposite direction.

8. The machine of any one of the preceding claims wherein movement of at least part of the handle controls the yaw of the machine.

9. The machine of claim 8 wherein rotation of the handlebars relative to the machine controls the yaw of the machine.

10. The machine of claim 8 or claim 9 including a tail propeller, the handlebars controlling the tail propeller to control the yaw of the machine.

11. The machine of claim 10 wherein the handlebars control the rotational speed of the tail propellers.

12. The machine of claim 8 or claim 9 or claim 11 wherein the handlebars are adapted to alter the characteristics of the contra-rotating propellers to produce a torque reaction to cause the machine to yaw.

13. The machine of claim 12 wherein the handlebars control the difference between the collective pitch of the blades of each contra-rotating propeller to produce a torque reaction.

14. The machine of claim 13 wherein the handlebars control the collective pitch of only one of the propeller blades to control the yaw of the machine.

15. The machine of any one of claims 10 to 14 wherein the handlebars control the relative speed of rotation of the propellers to control the yaw of the machine.

16. The machine of any one of the preceding claims wherein the machine comprises at least one throttle lever, movement of the throttle lever controlling the speed of the motor.

17. The machine of any one of the preceding claims wherein the handlebars comprise a twist grip, the rotation of which controls the collective pitch of the blades of at least one propeller to control the lift generated.

18. The machine of any one of the preceding claims, including a collective pitch mechanism for varying the collective pitch of the blades of the propellers, the mechanism including a swash plate connected to the propeller blades, movement of the swash plate relative to the propeller blades rotating the propeller blades about their longitudinal axes, thereby varying the pitch of the propeller blades.

19. The machine of claim 18 wherein the swashplate moves linearly in a direction parallel to the axis of rotation of the propellers, this linear movement being converted to rotational movement of the blades by means of a linkage connecting the swashplate to the blades.

20. The machine of claim 18 or 19 wherein each propeller is associated with a respective swashplate.

21. The machine of claim 20 including a transfer swash plate for transferring the motion of one swash plate to the other swash plate.

22. The machine of claim 21 wherein an actuator is provided to effect movement of one swash plate, the movement of said swash plate being transmitted to the other swash plate by the transfer swash plate, whereby the collective pitch of the blades of both propellers is controlled simultaneously by one actuator.

23. The machine of claim 20 wherein the movement of each swashplate is controlled by a respective actuator, the collective pitch of one propeller being controlled independently of the collective pitch of the other propellers.

24. The machine of any one of the preceding claims wherein the propeller is surrounded by a peripheral skirt.

25. The machine of claim 24 wherein said skirt comprises a plurality of vertically spaced rings, the gaps between the rings acting in use as ducts for supplying air to the propellers.

26. The machine of claim 25 wherein said ring has an airfoil shaped cross-section.

27. The machine of any one of the preceding claims wherein the base of the machine comprises a plurality of skids on which the machine rests when not in flight.

28. The machine of any one of the preceding claims wherein the base of the machine comprises a centrally mounted hub which facilitates movement of the machine when not in flight.

29. The machine of claim 28 wherein the hub comprises a ball rotatably mounted in a seat in the base of the machine.

30. An aircraft comprising at least one electric motor and two vertical axis contra-rotating propellers, the blades of the propellers being arranged to generate lift when the propellers are rotated by the motor, a handlebar being movably mounted on the aircraft above the propellers, movement of the handlebar relative to the aircraft effecting yaw control of the aircraft in use.

31. The machine of claim 30 wherein rotation of the handlebars relative to the chassis of the machine effects yaw control of the machine in use.

32. The machine of claim 30 or claim 31 comprising a tail propeller, the handlebars being arranged to control the tail propeller to control the yaw of the machine.

33. The machine of claim 32 wherein the handlebars are adapted to control the rotational speed of the tail rotor.

34. The machine of claim 30 or 30 wherein the handlebars are adapted to alter the characteristics of the contra-rotating propellers to produce a torque reaction to cause the machine to yaw.

35. The machine of claim 34 wherein the handlebars vary the difference between the collective pitch of each contra-rotating propeller to produce a torque reaction.

36. The machine of claim 35 wherein the handlebars control the collective pitch of only one of the propeller blades to control the yaw of the machine.

37. The machine of any one of claims 34 to 36 wherein the handlebars control the relative speed of rotation of the propellers to control the yaw of the machine.

38. The machine of any one of claims 30 to 37 wherein the handlebars comprise a twist grip, the rotation of which controls the collective pitch of the blades of at least one propeller to control the lift generated.

39. The machine of any one of claims 30 to 38 wherein the machine includes a collective pitch mechanism for varying the collective pitch of the propeller blades, including a swash plate connected to the propeller blades, movement of the swash plate relative to the propeller blades rotating the propeller blades about their longitudinal axes to vary the pitch of the propeller blades.

40. The machine of claim 39 wherein said swashplate moves linearly in a direction parallel to the axis of rotation of the propellers, this linear movement being converted to rotational movement of the blades by means of linkages connecting the swashplate to the blades.

41. The machine of claim 39 or 40 wherein each propeller is associated with a respective swashplate.

42. The machine of claim 41 including a transfer swash plate for transferring the motion of one swash plate to the other swash plate.

43. The machine of claim 42 wherein an actuator is provided to effect movement of one swashplate, the movement of said swashplate being transmitted to the other swashplate via the transfer swashplate, whereby the collective pitch of the blades of both propellers is controlled simultaneously by one actuator.

44. The machine of claim 41 wherein the movement of each swashplate is controlled by a respective actuator, the collective pitch of one propeller being controlled independently of the collective pitch of the other propellers.

45. An aircraft comprising at least one electric motor and two vertical axis contra-rotating propellers, the blades of the propellers being arranged to generate lift when the propellers are rotated by the motor, handlebars being mounted on the aircraft above the propellers, the aircraft further comprising a collective pitch mechanism for collectively controlling the pitch of the blades of the propellers, the collective pitch mechanism being controlled by the handlebars.

46. The machine of claim 45 wherein said handlebars comprise a twist grip, the rotation of which controls the collective pitch of the blades of at least one propeller, thereby controlling the lift generated.

47. The machine of claim 45 or 46 wherein said collective pitch mechanism comprises a swashplate connected to the propeller blades, movement of the swashplate relative to the propeller blades causing the propeller blades to rotate about their longitudinal axes, thereby changing the pitch of the propeller blades.

48. The machine of claim 47 wherein said swashplate moves linearly in a direction parallel to the axis of rotation of the propellers, this linear movement being converted to rotational movement of the blades by means of linkages connecting the swashplate to the blades.

49. The machine of claim 47 or 48 wherein each propeller is associated with a respective swashplate.

50. The machine of claim 49 including a transfer swash plate for transferring the motion of one swash plate to the other swash plate.

51. The machine of claim 50 wherein an actuator is provided to effect movement of one swash plate, the movement of said swash plate being transmitted to the other swash plate by the transfer swash plate, whereby the collective pitch of the blades of both propellers is controlled simultaneously by one actuator.

52. The machine of claim 48 wherein the movement of each swashplate is controlled by a respective actuator, the collective pitch of one propeller being controlled independently of the collective pitch of the other propellers.

53. An aircraft comprising at least one electric motor and two vertically-counter-rotating propellers, the propeller blades being rotated by the motor to rotate the propellers to generate lift, the aircraft further comprising a yaw control mechanism for varying the characteristics of at least one propeller relative to the other propeller so as to reduce torque reaction and effectively steer the aircraft to yaw.

54. The machine of claim 53 wherein the yaw control mechanism controls the difference between the collective pitch of the blades of each contra-rotating propeller to reduce torque reaction.

55. The machine of claim 54 wherein the yaw control mechanism controls the collective pitch of only one propeller to control the yaw of the machine.

56. The machine of claim 54 or claim 55 wherein the yaw control mechanism controls the relative speed of rotation of the propellers to control the yaw of the machine.

57. The machine of any one of claims 53 to 56 wherein the yaw control mechanism includes a collective pitch mechanism for varying the collective pitch of the blades of the propellers, the collective pitch mechanism including a swashplate connected to the blades of the propellers, movement of the swashplate relative to the blades of the propellers rotating the blades of the propellers about their longitudinal axes to vary the pitch of the blades of the propellers.

58. The machine of claim 57 wherein the swashplate moves linearly in a direction parallel to the axis of rotation of the propellers, this linear movement being converted to rotational movement of the blades by a linkage connecting the swashplate and the blades.

59. The machine of claim 57 or 58 wherein each propeller is associated with a respective swashplate.

60. The machine of claim 59 wherein the movement of each swashplate is controlled by a respective actuator, such that the collective pitch of the blades of one propeller is controlled independently of the collective pitch of the blades of the other propellers.

61. An aircraft comprising at least one electric motor and two vertical-axis contra-rotating propellers, the blades of the propellers being arranged to generate lift when the propellers are rotated by the motor, the aircraft being equipped with a seat and a handle mounted on the aircraft above the propellers, and a hub projecting below the propellers and below the lowest part of the aircraft, the hub partially supporting the aircraft in a tilted orientation when the aircraft is at rest, the user being able to control the aircraft during takeoff, with the aircraft in a non-tilted orientation, with the aircraft supported by the hub branches and partially by the lift generated by the propellers.

62. An aircraft comprising at least one electric motor and two vertical axis counter-rotating propellers, the blades of the propellers being arranged to generate lift when the propellers are rotated by the motor, a load bearing zone being provided above the propellers, each propeller being provided with a respective blade pitch control mechanism, the aircraft further comprising a controller, the blade pitch control mechanisms and controller being arranged such that the pitch of the blades of one propeller can be controlled independently of the pitch of the blades of the other propeller.

63. The machine of claim 62 wherein the blade pitch control mechanism and controller are arranged such that each of the collective and cyclic pitch of the blades of one propeller is independently controllable relative to each of the collective and cyclic pitch of the blades of the other propeller.

64. The aircraft of claim 62 or 63, wherein at least one blade pitch control mechanism is actuated by a servo mechanism controlled by the controller.

65. The machine of claim 64 wherein each blade pitch control mechanism is controlled by a respective servo mechanism.

66. The machine of claim 65 wherein each blade pitch control mechanism is provided by its own set of servomechanisms, one for each propeller blade.

67. The machine of any one of claims 62 to 66 wherein each propeller is driven by a respective drive shaft, the drive shafts being coaxial, at least one of the drive shafts being hollow, such that at least one of the blade pitch control mechanisms is contained within that drive shaft.

68. An aircraft comprising at least one electric motor and two vertical axis contra-rotating propellers, the blades of the propellers being arranged to generate lift when the propellers are rotated by the electric motor, a passenger compartment being mounted above the propellers.

69. The aircraft of claim 68, wherein said passenger compartment is elongated and configured to extend along a longitudinal axis of the aircraft, the compartment having a width less than a width of the aircraft.

70. The aircraft of claim 69, wherein said passenger compartment comprises a stretcher for carrying injured personnel.

71. The machine of any one of the preceding claims, comprising a propulsion fan assembly comprising a rearwardly directed propeller mounted for rotation about an axis perpendicular to the axis of rotation of the propeller of the vertical axis and arranged to direct the propeller rearwardly, in use, to generate additional thrust.

72. The machine of any one of the preceding claims wherein the machine comprises at least one moveably mounted wing, the angle of inclination of which is adjustable relative to the machine.

73. The aircraft of claim 72, wherein the movably mounted wing is mounted for rotation about a horizontal axis extending transversely through the aircraft.

74. The aircraft of claim 72 or 73, wherein a plurality of movable wings are provided.

75. The aerial vehicle of claim 74 wherein the first set of movable wings is disposed forward of the aerial vehicle and the second set of movable wings is disposed aft of the aerial vehicle.

76. An aircraft comprising at least one electric motor and two vertical axis contra-rotating propellers, the blades of the propellers being arranged to generate lift when the propellers are rotated by the motor, a load bearing zone being provided above the propellers, a controller being provided, the controller comprising a plurality of gyroscopes for generating signals indicative of attitude of the aircraft, the controller being capable of processing the signals and controlling the aircraft to maintain the aircraft in a predetermined attitude.