IL127888A - Control system for powered parachutes - Google Patents

Description

CONTROL SYSTEM FOR POWERED PARACHUTES FIELD OF INVENTION The present invention relates to light aircraft comprising a parachute also known as powered parachutes.

SUMMARY OF INVENTION The present invention relates to a control system for a light aircraft, said light aircraft comprising a suitable aircraft carriage suspended from a suitable parachute wing via suitable primary rigging lines, said parachute wing further comprising at least one set of port rigging lines and least one set of starboard rigging lines suitably attached to at least a portion of the port half of the said parachute wing and to at least a starboard portion of said parachute wing, respectively, such that a predetermined pulling action on at least some of the said port or starboard rigging lines results in at least a corresponding portion of the trailing edge of the said port half or said starboard half, respectively, of said parachute wing to be at least partially collapsed and change the lift and drag generated thereat, said aircraft carriage comprising a suitable undercarriage comprising a front wheel turnable at about a turning axis such as to enable the said carriage to be steered when said undercarriage is in substantial contact with the ground, the said control system comprising:- a control rod tiltable about a first axis intermediate a first longitudinal end and a second longitudinal end of said rod; a coupler reciprocally rotatable about a second axis, said second axis disposed at an angle to said first axis different from zero, said coupler being in contact with said second end of said control rod, said coupler adapted to rotate about said second axis in response to a rotating action of said control rod about said first axis; transmission means for transmitting said rotation of said coupler about said second axis to said front wheel such as to provide a corresponding rotation of said front wheel about said turning axis in response to the rotation of said coupler about said second axis.

BRIEF DESCRIPTION OF FIGURES Figure 1 illustrates, in exploded perspective view, the structural characteristics of a powered parachute according to the prior art.

Figure 2 illustrates, in front view, the structural characteristics of a preferred embodiment of the present invention: Figure 2a: control rod in neutral position, front wheel aligned with aircraft longitudinal axis; Figure 2b: control rod tilted to port side, wheel steered to port side.

Figure 3 illustrates, in side view, the structural characteristics of a preferred embodiment of the present invention: Figure 3a: control rod in neutral position, front wheel aligned with aircraft longitudinal axis; Figure 3b: control rod tilted to port side, wheel steered to port side.

Figure 4 illustrates, in plan view, the structural characteristics of a preferred embodiment of the present invention: Figure 4a: control rod in neutral position, front wheel aligned with aircraft longitudinal axis; Figure 4b: control rod tilted to port side, wheel steered to port side.

Figure 5 illustrates, in perspective view, the structural characteristics of a preferred embodiment of the present invention: Figure 5a: control rod in neutral position, front wheel aligned with aircraft longitudinal axis; Figure 5b: control rod tilted to port side, wheel steered to port side.

DESCRIPTION The present invention is defined by the claims, the contents of which are to be read as included within the disclosure of the specification, and will now be described by way of example with reference to the accompanying Figures.

A typical light aircraft of the type comprising a suitable aircraft carriage suspended from a suitable parachute wing is shown schematically in exploded view in Figure 1. This type of light aircraft is also known as a powered parachute. The aircraft (10) comprises a carriage (20) with a seat (30) for the pilot and optionally further seats for 1 or 2 passengers (not shown), typically mounted aft with respect to the pilot. An engine (40) having a pusher propeller (45) is mounted onto the carriage (20) behind the pilot (and passengers). The carriage (20) comprises a typical tricycle landing gear, having a pair of opposed fixed rear wheels, and a front wheel (50) pivotable about a turning axis (52) to enable the aircraft to be steered on the ground, particularly during taxiing, takeoffs and landings.

The carriage (20) is typically suspended from, and thus in flight supported by, a parachute wing (60). Typically, the parachute wing (60) is made from suitable fabric similar to that of regular parachutes. In flight mode, the parachute wing (60) is approximately rectangular in plan view and approximately arcuate in front and rear view, and has an aerofoil-shaped cross-sectional profile to enable lift to be generated by forward motion of the wing. The shape of the wing is maintained by the airflow.

The carriage (20) is suspended by means of primary rigging lines (70) connected to spaced points on the parachute wing (60) and brought together, typically to two support lines, one port (76) and one starboard (78), attached to suspension points (not shown) on the carriage (20). Further, port and starboard rigging lines (72), (74) are connected to points along the trailing edge of at least a portion of the port half and at least a portion of the starboard half, respectively, of the parachute wing (60). The port and starboard rigging lines (72), (74) are brought together to port and starboard control lines (82), (84), respectively, which pass onto the pilot. By pulling or drawing on either control line (82), (84) separately, the pilot is able to change the lift and drag of the corresponding half of the parachute wing (60), enabling the aircraft to turn in either direction, and by pulling or drawing on both control lines (82), (84) at the same time, a braking maneouvre may be effected.

In the prior art, the control lines (82), (84) are attached typically to the free ends (or near thereto) of port and starboard control rods (92), (94) respectively, which are pivotally attached at the other ends thereof to the carriage (20). The pivot axes of the port and starboard control rods (92), (94) are typically vertical, enabling the control rods (92), (94) to be angularity displaced along a substantially horizontal plane. The control rods (92), (94) are actuable by the pilot's feet, and thus the pilot is able to control the parachute wing (60), and thus the aircraft (10) in flight, with his feet.

Engine control in the prior art is typically effected by means of a throttle stick (42) linked by a cable to the engine throttle, and the throttle stick is operable by either one of the pilot's hands.

Ground steering of the front wheel (50) in the prior art is typically accomplished by means of steering lever (55) pivotable mounted onto the said carriage such as to permit to be tilted in a forwards-backwards direction. A strut (56) pivotably mounted to the steering lever (55) and to the port or starboard side of the housing of the front wheel (50) enables the wheel (50) to be turned clockwise or counter-clockwise about the turning axis (52) in response to a forwards or rearwards tilting action, respectively of the steering lever ( 5). The steering lever (55) is actuated by the free hand of the pilot.

Thus, in the prior art, the pilot requires the use of both his hands and legs during take-off to steer the carriage, control the engine, and control the wing. In flight, both feet are required for controlling the wing, and one hand is required for controlling the engine. Further, the fore-aft actuation of the steering lever to effect a port-starboard steering maneouvre on the ground may be confusing for some pilots and contribute to the probability of pilot error.

Other control configurations are disclosed in the prior art, such as in US 4,875,642, wherein the front wheel is steered by means of foot bars on either side of the front wheel; wing control is by means of a free handle-bar unit to which the control lines (82), (84) are attached at the ends thereof; and the engine is controlled by means of an engine twist throttle. However, during takeoff, landing and taxiing, the pilot needs to use both arms and legs for controlling the aircraft, and in flight while his legs are free, the control movements to each of the control lines (82), (84) are linked by means of a unitary handle bar unit. In other words, when turning the aircraft in one direction, the pilot has pull on one side of the handle bar unit to draw on one of the control lines, while being careful not to pull the other end of the handle bar unit which carries the other control line. This is not an easy way to control the aircraft, particularly since the handle bar unit is not fixed to a column but is free, thereby increasing the stress on the pilot.

In the present invention, control of the aircraft, both on the ground and in flight, is more straightforward and simple than in the prior art, and does not require the use of the feet in either mode. Such a control system is particularly useful for paraplegic and handicapped pilots who have little or no power in, or control of, their legs.

The present invention thus relates to a control system for a light aircraft of the type described, i.e., wherein said light aircraft (10) comprises a suitable aircraft carriage (20) suspended from a suitable parachute wing (60) via a primary rigging lines, (70). The said parachute wing further comprising at least one set of port rigging lines (72) and least one set of starboard rigging lines (74) suitably attached to at least a portion of the port half of the said parachute wing and to at least a starboard portion of said parachute wing, respectively. The port and starboard rigging lines, (72), (74) are respectively brought together to port and starboard control lines (82), (84), as hereinbefore described. Thus, a predetermined pulling action the said port control line (82) or starboard control line (84) results in at least a corresponding portion of the trailing edge of the said port half or said starboard half, respectively, of said parachute wing (60) to be at least partially collapsed, thereby reducing lift thereat, and enabling the aircraft to turn in either direction or to brake if both the port control line (82) and starboard control line (84) are pulled together. The said aircraft carriage (20) comprises a suitable undercarriage comprising a front wheel (50) turnable at about a turning axis (52) as hereinbefore described, such as to enable the said carriage to be steered when said undercarriage is in substantial contact with the ground. Thus, with reference to Figures 2 to 5, the control system (100) of the present invention comprises:- a control rod (120) tiltable about a first axis (220) intermediate a first longitudinal end (122) and a second longitudinal end (124) of said control rod; a coupler (140) reciprocally rotatable about a second axis (240) said second axis (240) disposed at an angle to said first axis (220) different from zero, said coupler (140) being in contact with said second end (124) of said control rod (120), said coupler (140) adapted to rotate about said second axis (240) in response to a rotating action of said control rod (120) about said first axis (220); transmission means (160) for transmitting said rotation of said coupler (140) about said second axis (240) to said front wheel (50) such as to provide a corresponding rotation of said front wheel (50) about said turning axis (52) in response to the rotation of said coupler (140) about said second axis (240).

Preferably, the said first axis (220) is orthogonal to said second axis (240), though alternatively the first and second axes (220), (240) may be set at any desired angle to each other. Preferably, the said first axis (220) is substantially aligned with the longitudinal axis (110) of the said carriage (20), and said second axis (240) is also substantially orthogonal to the port-starboard direction. Thus, the said control rod (120) is tiltable from port to starboard and back to port along a plane substantially normal to the longitudinal axis (110) of the carriage (20).

Typically, said control rod (120) is shaped such as to minimize obstruction of the instrument panel (199) which is typically mounted between the pilot and the front wheel (50). Thus, in the preferred embodiment, the control rod (120) comprises two approximately 90° bends such that the lower portion of the control rod (120) is displaced forward with respect to the upper portion of the control rod (120), and thus enable the said second end (124) of the control rod to be coupled with coupler (140) in a position forward of the instrument panel (199). This simple arrangement minimises obscurity of the instrument panel (199) by the control rod (120), and provides an improvement over the prior art in which the throttle stick (42) is situated in front of the instrument panel (199), and thus in the line of view of the pilot.

Preferably, the height of said control rod (120) is adjustable, enabling the control system (100) to be optimally positioned for pilots of widely differing heights. The control rod (120) may thus be comprised, for example, of two interconnected telescopic elements which are mutually lockable within a predetermined range of heights by means, for example, of a locking pin. Many other forms of adapting the said control rod (120) to be height adjustable are disclosed in the art.

In the preferred embodiment, the coupler (140) comprises a typically triangular plate (142) orthogonal to said second axis (240). The plate (142) comprises a suitably profiled rearwards-facing trailing edge (144), typically arcuate, in contact with said second end (124) of said control rod (120). Thus, as said rod (120) is tilted about said first axis (220), the said second end (124) of said rod (120) imparts a suitable translational motion onto said trailing edge (144) in a direction substantially orthogonal to said first and said second axes, (220), (240), i.e., in a substantially port-starboard direction. The said trailing edge (144) is characterised in comprising a suitable profile, such as for example a concave arch, so as to enable a rotational motion to be imparted onto said plate (142) about said second axis (240) in response to said translational motion.

The said coupler (140) comprises at least a port portion projecting radially from said second axis (240). Thus in the preferred embodiment wherein said coupler comprises said triangular plate (142), the plate (142) is typically symmetrical having its apex replaced by said trailing edge (144), and comprises an angled corner (145) on the port side. The said transmission system comprises :- at least a port strut (163) pivotably attached at a first end (161) thereof to said port portion, i.e., said port angled corner (145) of said coupler (140) and second end (162) thereof to a port projection comprised on a housing (58) of said front wheel (50) and radially displaced from said turning axis (52).Thus, a rotational movement of said coupler (140) is transmitted to said front wheel (50) via said port strut (163) as a rotational movement of said front wheel (50) about said turning axis (52).

Alternatively or additionally, the said coupler (140) optionally comprises at least a starboard portion projecting radially from said second axis (240), said starboard portion in the preferred embodiment being a starboard angled corner (146) of said plate (142). Thus, the transmission system alternatively or additionally comprises :- at least a starboard strut (166) pivotably attached at a first end (167) and second end (168) thereof to said starboard portion of said coupler (140) and to a starboard projection comprised on a housing (58) of said front wheel (50) and radially displaced from said turning axis (52), respectively. Thus, a rotational movement of said coupler (140) is transmitted to said front wheel (50) via said starboard strut (166) as a rotational movement of said front wheel (50) about said turning axis (52).

The said control rod (120) and coupler (140) may be mounted to the carriage (20) by means of any suitable brackets (130) capable of permitting the required movement of the control rod (120) and coupler (140) about the said first axis (220) and second axis (240), respectively.

The control system of the present invention preferably further comprises at least one starboard control bar (1 4) for controlling the lift of said starboard half of said parachute wing (60), said starboard control bar (194) being pivotably mounted at one end thereof onto said first end (122) of said control rod (120) at a starboard pivot (196) thereat. Thus, this arrangement permits said starboard bar (194) to be rotated about said starboard pivot (196). The said starboard rigging lines (74) are suitably attached to said starboard bar (194), typically via said corresponding control line (84), such that a predetermined angular displacement of said starboard bar (194) about said starboard pivot (196) results in a predetermined pulling action on at least some of the said starboard rigging lines (74) such that at least a corresponding portion of the trailing edge of the said starboard half of said parachute wing (60) is at least partially collapsed reducing lift thereat.

Alternatively or additionally, the control system of the present invention preferably further optionally comprises at least one port control bar (192) for controlling the lift of said port half of said parachute wing (60), said port control bar (192) being pivotably mounted at one end thereof onto said first end (122) of said control rod (120) at a port pivot (198) thereat. Thus, this arrangement permits said port bar (192) to be rotated about said port pivot (198). The said port rigging lines (72) are suitably attached to said port bar (192), typically via said corresponding control line (82), such that a predetermined angular displacement of said port bar (192) about said port pivot (198) results in a predetermined pulling action on at least some of the said port rigging lines (72) such that at least a corresponding portion of the trailing edge of the said port half of said parachute wing (60) is at least partially collapsed reducing lift thereat.

Thus by pulling on the starboard bar (194) the aircraft (10) may be turned in flight in the starboard direction, and by pulling the port bar, the aircraft (10) may be turned in the port direction. Of course, by pulling on both the port bar (192) and the starboard bar (194), a braking maneouver may be effected.

Since the port bar (192) and the starboard bar (194) are mounted onto the said first end (122) of the said control rod (120), the pilot advantageously initiates tilting movement of the control bar (120) by means of an appropriate action on one or both of said port bar (192) and said starboard bar (194).

Since the freedom of movement of each of the port rod (192) and starboard rod (194) is independent with respect to that of the control rod (120), the wing (60) may be controlled independently of, or together with, the steering of the front wheel. This is possible by actuating the appropriate port rod (192) or starboard rod (194) either when said control rod (120) is in the neutral position, or when tilted to the port or starboard direction, respectively.

Preferably, the said starboard control bar (194) comprises a handgrip (184) suitably mounted thereto adapted to be gripped by the a hand of the pilot of said light aircraft to facilitate control thereof by said pilot. Preferably, said handgrip (184) comprises a grippable bar parallel to and rearwardly spaced from said starboard control bar (194).

Alternatively or additionally, said port control bar (192) comprises a handgrip (182) suitably mounted thereto adapted to be gripped by the a hand of the pilot of said light aircraft to facilitate control thereof by said pilot. Preferably, said handgrip (182) comprises a grippable bar parallel to and rearwardly spaced from said port control bar (192).

As hereinbefore described, said aircraft (10) typically comprises a propulsion engine (40) suitably mounted onto said carriage (20). Preferably, the control system of the present invention comprises a suitable twist throttle (48) operatively connected to the throttle of the engine for controlling said engine. The said twist throttle (48) is advantageously comprised on said port bar (192) or said starboard bar (194), and preferably to said handgrip (182) on said port control bar (192) or to said handgrip (184) on said starboard control bar (194). Thus, the twist throttle enables the pilot to control the engine with one hand while using the same hand to control one side of the parachute wing (60) when actuating either the port bar (192) or starboard bar (194), and/or when steering the wheel (50) by tilting the said control rod (120) to the port side or starboard side.

While in the foregoing description describes in detail only a few specific embodiments of the invention, it will be understood by those skilled in the art that the invention is not limited thereto and that other variations in form and details may be possible without departing from the scope and spirit of the invention herein disclosed.

Claims (12)

1. CLAIMS:- L A control system for a light aircraft, said light aircraft comprising a suitable aircraft carriage suspended from a suitable parachute wing via suitable primary rigging lines, said parachute wing further comprising at least one set of port rigging lines and least one set of starboard rigging lines suitably attached to at least a portion of the port half of the said parachute wing and to at least a starboard portion of said parachute wing, respectively, such that a predetermined pulling action on at least some of the said port or starboard rigging lines results in at least a corresponding portion of the trailing edge of the said port half or said starboard half, respectively, of said parachute wing to be at least partially collapsed and change the lift and/or drag generated thereat, said aircraft carriage comprising a suitable undercarriage comprising a front wheel turnable at about a turning axis such as to enable the said carriage to be steered when said undercarriage is in substantial contact with the ground, the said control system comprising:- a control rod tiltable about a first axis intermediate a first longitudinal end and a second longitudinal end of said rod; a coupler reciprocally rotatable about a second axis, said second axis disposed at an angle to said first axis different from zero, said coupler being in contact with said second end of said control rod, said coupler adapted to rotate about said second axis in response to a rotating action of said control rod about said first axis; transmission means for transmitting said rotation of said coupler about said second axis to said front wheel such as to provide a corresponding rotation of said front wheel about said turning axis in response to the rotation of said coupler about said second axis.

2. A control system as claimed in claim 1, wherein said first axis is substantially orthogonal to said second axis.

3. A control system as claimed in any preceding claim, wherein said first axis is substantially aligned with the longitudinal axis of the said carriage, and said second axis is substantially orthogonal to the port-starboard direction.

4. A control system as claimed in any preceding claim, wherein said coupler comprises a plate orthogonal to said second axis said plate having an arcuate trailing edge in contact with said second end of said control rod, such that as said rod is tilted about said first axis said second end of said rod imparts a suitable translational motion onto said trailing edge in a direction substantially orthogonal to said first and said second axes, said trailing edge comprising a suitable profile such as to enable a rotational motion to be imparted onto said plate about said second axis in response to said translational motion.

5. A control system as claimed in any preceding claim, wherein said coupler comprises at least a port portion projecting radially from said second axis, said transmission system comprising :- at least a port strut pivotably attached at a first end and second end thereof to said port portion of said coupler and to a port projection comprised on a housing of said front wheel and radially displaced from said turning axis, respectively, such that a rotational movement of said coupler is transmitted to said front wheel via said port strut as a rotational movement of said front wheel about said turning axis.

6. A control system as claimed in any preceding claim, wherein said coupler further comprises at least a starboard portion projecting radially from said second axis, said transmission system comprising :- at least a starboard strut pivotably attached at a first end and second end thereof to said starboard portion of said coupler and to a starboard projection comprised on a housing of said front wheel and radially displaced from said turning axis, respectively, such that a rotational movement of said coupler is transmitted to said front wheel via said starboard strut as a rotational movement of said front wheel about said turning axis.

7. A control system as claimed in any preceding claim, further comprising at least one starboard control bar for controlling the lift of said starboard half of said parachute wing, said starboard control bar being pivotably mounted at one end thereof onto said first end of said control rod at a starboard pivot thereat such to permit said starboard bar to be rotated about said starboard pivot, and wherein said starboard rigging lines are suitably attached to said starboard bar such that a predetermined angular displacement of said starboard bar about said starboard pivot results in a predetermined pulling action on at least some of the said starboard rigging lines such that at least a corresponding portion of the trailing edge of the said starboard half of said parachute wing is at least partially collapsed changing the lift and drag thereof.

8. A control system as claimed in claim 7, wherein said starboard control bar comprises a handgrip suitably mounted thereto adapted to be gripped by the a hand of the pilot of said light aircraft to facilitate control thereof by said pilot.

9. A control system as claimed in any preceding claim, further comprising at least one port control bar for controlling the lift of said port half of said parachute wing, said port control bar being pivotably mounted at one end thereof onto said first end of said control rod at a port pivot thereat such to permit said port bar to be rotated about said port pivot, and wherein said port rigging lines are suitably attached to said port bar such that a predetermined angular displacement of said port bar about said starboard pivot results in a predetermined pulling action on at least some of the said port rigging lines such that at least a corresponding portion of the trailing edge of the said port half of said parachute wing is at least partially collapsed changing the lift and drag thereof

10. A control system as claimed in claim 9, wherein said port control bar comprises a handgrip suitably mounted thereto adapted to be gripped by the a hand of the pilot of said light aircraft to facilitate control thereof by said pilot.

11. 1 1.A control system as claimed in any preceding claim, wherein said light aircraft comprises a suitable propulsion engine suitably mounted onto said carriage, and wherein said engine is controlled by means of a suitable twist throttle operatively connected to the throttle of the engine. 127888 /2 18

12. A control system as claimed in claim 10, wherein said twist throttle is comprised on said hand grip suitably mounted to said port control bar or to said starboard control bar. UZZATTO & LUZZATTO