WO2012026830A1

WO2012026830A1 - Mechanism and method for adjustment of a kite control line

Info

Publication number: WO2012026830A1
Application number: PCT/NZ2011/000163
Authority: WO
Inventors: Richard John Roake; Gerald Neil Kapoor; Shannon Mead; Andrew Francis Kay
Original assignee: Control Bar Design Limited
Priority date: 2010-08-23
Filing date: 2011-08-23
Publication date: 2012-03-01
Also published as: NZ587522A

Abstract

A method of adjusting a wing of a traction kite during flight, the kite including a control bar connected to the wing, the method including the step of: operating an activator located on the control bar to activate an actuator configured to adjust a control line connected to the wing wherein the actuator includes an hydraulic circuit.

Description

MECHANISM AND METHOD FOR ADJUSTMENT OF A KITE CONTROL LINE

TECHNICAL FIELD

The present invention relates to an adjustment mechanism and method of use for adjusting a control line of a traction kite configured to provide a traction force and/or for lifting or pulling a load via control lines attached to a wing, and particularly to an adjustment mechanism and method of use for adjustment of the kite during flight.

BACKGROUND ART

The use of kites is increasingly common in many activities, especially sport and recreational activities involving the use of an inflatable wing configured as a traction kite to provide traction to a person on a device for moving or sliding over water (kitesurfing, kiteboarding etc) or land (kite buggying, kiteskiing, etc).

The traction kite is typically controlled/steered by an operator manually manipulating a rigid control bar. The control bar is typically connected to the kite wing by two control lines which are adjusted to control the trailing edge of the wing. These trailing edge control lines are typically connected to either end of the control bar. An operator can adjust the wing by moving the control bar to increase or decrease the tension in the control lines.

A traction kite, as applicable to the present invention, includes a further, leading edge control line which is connected to the leading edge of the kite wing at one end and at the other end to a harness release mechanism for a harness which, in use, is worn by the operator. The leading edge control line, which passes through an aperture in the control bar, provides the main traction force from the kite wing to the operator.

An operator can move the control bar along the leading edge control line to alter the relationship between the leading edge and the trailing edge of the wing and thus alter the flight characteristics of the kite.

Some existing kites include an adjustment mechanism on the leading edge control line. This usually consists of a pulley system on the leading edge control line. The length of the leading edge control line can be set by an operator adjusting the pulley system prior to the flight. Once set the length of the leading edge control line remains fixed during the flight. The pulley system is typically adjusted to provide the length of the leading edge control line that the operator considers to be appropriate for the conditions expected during the flight. The trim of the kite wing can then be altered/controlled by the operator moving the control bar with respect to the leading edge control line to move the trailing edge of the wing relative to the (fixed) leading edge. However, one disadvantage with this arrangement is that the range of motion of the control bar is limited by the reach of the operator. This limited range may be insufficient to enable the operator to maintain the desired trim for the kite during flight.

In such cases the solution is for the operator to stop the flight (by de-powering the wing), and then access and adjust the pulley system to provide a new, and hopefully improved, length for the leading edge control line. In many cases, such as when the kite is being used for kite surfing or board kiting, the sea conditions may be such that it is not possible to adjust the pulley system until the operator and kite are returned to dry land. In any event, readjusting the length of the leading edge control line can be time consuming and generally inconvenient.

It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.

All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.

Throughout this specification, the word "comprise", or variations thereof such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps. Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

DISCLOSURE OF THE INVENTION

According to one aspect of the present invention there is provided a method of adjusting a wing of a traction kite during flight, the kite including a control bar connected to the wing, the method including the step of: operating an activator located on the control bar to activate an actuator configured to adjust a control line connected to the wing.

In a preferred embodiment the step of operating the activator activates an hydraulic system. In a preferred embodiment the step of operating the activator activates the actuator to adjust a trailing edge control line.

In a preferred embodiment the step of operating the activator activates the actuator to adjust two trailing edge control lines. In a preferred embodiment both trailing edge control lines are adjusted at substantially the same time.

In a preferred embodiment both trailing edge control lines are adjusted by substantially the same amount.

In another preferred embodiment the step of operating an activator activates the actuator to adjust a leading edge control line.

In a preferred embodiment the step of operating the activator activates the actuator to operate a winch assembly connected to the leading edge control line.

In a preferred embodiment the step of operating the activator includes moving a lever mounted on the control bar. In a preferred embodiment the lever is connected to a piston of an hydraulic actuator.

According to another aspect of the present invention there is provided a control line adjustment mechanism for in-flight adjustment of a control line connected to a wing of a traction kite, the kite including a control bar connected to the wing, the mechanism including: a winding mechanism configured to attach to the control line; and an actuator configured to activate the winding mechanism; characterised in that the actuator is activated by an activator incorporated into the control bar.

Reference to a control bar throughout this specification should be understood to mean a rigid bar connected by control lines to a wing of a traction kite for use by an operator to control the wing of the kite, as is well known to those skilled in the art. In all preferred embodiments of the present invention at least part of the control bar is hollow.

Reference to an activator throughout this specification should be understood to refer very broadly to any device configured to initiate a response, typically motion of some type. Thus, without limitation, an activator may be a button, lever, or switch, typically configured to activate another device or process, such as movement of a solid or gas, or operation of a solenoid valve, a hydraulic, pneumatic, electrical actuator (or combination of thereof) in either linear, rotary or helical configuration, and so on. An activator as used here includes reference to a switch for example, where the switch initiates (or stops) a flow of electricity.

In a preferred embodiment the activator includes a lever. Preferably the lever is formed as a handle grip, similar to those commonly used for bicycle brake levers, where the lever is pivotally mounted to the control bar.

In a preferred embodiment the adjustment mechanism includes a second activator on the control bar.

Preferably the first and the second activators are spaced apart on the control bar, so that at least one activator is in the vicinity of a normal hand hold for each hand of an operator. In a preferred embodiment a first activator is operated to activate the actuator to wind in the control line.

In a preferred embodiment a second activator is operated to activate the actuator to wind out the control line.

In a preferred embodiment the actuator includes an hydraulic circuit. In a preferred embodiment at least part of the hydraulic circuit is incorporated into the control bar.

In a preferred embodiment the winding mechanism includes a winch assembly.

In a preferred embodiment the winch assembly is connected to a leading edge control line.

In another preferred embodiment the winding mechanism includes a spool attached to the control bar.

In a preferred embodiment the spool is configured to attach to a trailing edge control line.

In a preferred embodiment the actuator includes a helical rotary hydraulic actuator configured to rotate the spool.

An adjustment mechanism according to the present may provide several advantages over the prior art traction kites, particularly as adjustment of the leading edge control line or the trailing edge control lines may be carried out while the traction kite is in flight. An operator can operate a handle grip on the control bar to make the adjustment without the need to de-power the kite. Furthermore, the ability to adjust the control lines by operating a handle grip on the control bar may increase the range of adjustment available to the operator beyond that available in prior art kites, where the range (during a flight) is limited by the operator's reach. BRIEF DESCRIPTION OF THE DRAWINGS

Further aspects of the present invention will become apparent from the ensuing description which is given by way of example only and with reference to the accompanying drawings in which:

Figure 1 Shows a schematic view of an adjustment mechanism for in-flight adjustment of a control line according to one embodiment of the present invention; and

Figure 2 shows a control bar for a traction kite according to one embodiment of the

present invention, and

Figure 3 shows a schematic view through a cross section of the control bar shown in

Figure 2; and

Figure 4 shows a schematic exploded view of the components of an adjustment

mechanism according to the embodiment shown in Figure 2; and

Figure 5 shows a schematic view of the interior of a winding mechanism according to one embodiment of the present invention; and Figure 6 shows a schematic exploded view of the components of the winding mechanism shown in Figure 6; and

Figure 7 shows a schematic view of a control bar according to another embodiment of the present invention; and

Figure 8 shows a schematic view of the components of a winding mechanism according to the embodiment shown in Figure 7.

BEST MODES FOR CARRYING OUT THE INVENTION

An adjustment mechanism for in-flight adjustment of a control line of a traction kite according to one embodiment of the present invention is generally indicated by arrow 1 in Figure 1.

The traction kite includes a control bar 2 which is connected to the kite wing (not shown) by two trailing edge control lines 3 and 4. The control bar includes an aperture 5 through the mid-point of the control bar. A leading edge control line 6 is connected at one end to the leading edge of the kite wing (not shown) and passes through the aperture 5 in the control bar to connect at the other end to a harness release mechanism 7. The harness release mechanism is connected by a cable 8 to a harness (not shown) which is worn by an operator of the kite during flight. The adjustment mechanism according to this embodiment includes a winding mechanism in the form of a winch assembly 9 which is connected into the leading edge control line 6 between the control bar 2 and the leading edge of the kite wing.

The winch assembly 9, which is described in more detail below, is configured to wind in to shorten the effective length of leading edge control line 6, or wind out to increase the effective length of leading edge control line by releasing it from the winding assembly. Both the wind-in and wind-out actions utilise an hydraulic actuator which is incorporated into the control bar 2 as discussed below.

The activator includes two levers, 10 and 11 , mounted one on each side of the control bar 2. The levers are formed as handle grips, 10 and 11 which may be activated by an operator by squeezing the lever towards the control bar, as is well known, for example, in a bicycle brake handle grip. In use the handle grips are in front of the operator and in the vicinity of the normal hand grip of the operator on the control bar so that they can be readily accessed and activated in the usual manner by the operator. Each of the two handle grips 10 and 11 activates one of two actuators each having a separate closed hydraulic circuit. The first hand grip, 10, activates a wind-in mechanism in the winding assembly 9 by activating a closed hydraulic circuit which provides pressure to the winding assembly through a flexible hydraulic line 12. The second handle grip, 11 , activates a wind-out mechanism in the winding assembly 9 by activating another closed hydraulic circuit which provides pressure to the winding assembly through another flexible hydraulic line 13. An hydraulic actuator for each circuit is contained within the control bar 2 as outlined below.

The control bar is shown in Figure 2 and in a horizontal cross section in Figure 3. An exploded view of the control bar assembly, generally indicated by arrow 14, is shown in Figure 4.

The control bar assembly 14 includes a first cover 15 and a second cover 16, the covers configured to contain the actuators for each of the two closed hydraulic circuits. The two covers are bolted together, and two end caps, 17 and 18, fitted to the ends of the joined covers to seal the ends of the control bar assembly 14.

The activator for the wind-in circuit includes the handle grip 10 which is attached to the control bar 2 by the pivot 19. The handle grip acts on a first connecting rod 20 to move a two stage piston having a first stage piston 21 and a second stage piston 22 which moves inside a first cylinder 23. Activation of the piston (21 and 22) by the handle grip 10 displaces hydraulic fluid into the flexible hydraulic line 12 which connects with the wind-in mechanism in the winch assembly 9. The two stage piston arrangement allows for easier pumping in the initial movement of the handle grip 10 (the first part of the stroke), and higher pressure during further movement of the handle grip (the second part of the stroke). The actuator for the wind-out circuit is similar to the wind in circuit describe above except that it uses a single cylinder. The wind-out circuit includes the handle grip 11 which is attached to the control bar 2 by the pivot 24. The handle grip acts on a first connecting rod 25 to move the piston 26 inside a second cylinder 27. Activation of the piston 26 by the handle grip 11 displaces hydraulic fluid into the flexible hydraulic line 13 which connects with the wind-out mechanism in the winch assembly 9.

The handle grip positions are adjustable in and out for convenience using the adjusting pins 28 and 29 (for handle grips 10 and 11 respectively). The adjusting pins 28 and 29 move the pressure point of the respective handle grips 10 and 11 to allow each handle grip to

independently move closer to or further away from the control bar 2.

A schematic perspective view of the winch assembly 9 in this embodiment is shown in Figure 5. An exploded view of the components of the winch assembly is shown in Figure 6. The winch assembly 9 includes a base plate 31 to which is mounted a ratchet assembly, generally indicated by arrow 32 in Figure 6. A pulley 33 is attached to a shaft 34 which is mounted to the base plate 31 by a bearing 35 and bearing retainers 36 and 37, one on each side of the base plate. The shaft is sealed on the pulley side by a seal 38. The pulley can be easily removed and replaced with different sizes to allow additional control of line length adjustment. The remainder of the winch mechanism is kept sealed on the side of the base plate 31 distal to the pulley 33. An escapement gear 39 is fitted over and keyed to the shaft 34. The tooth profile of the escapement gear allows ratcheting in one direction, and controlled release in the other. A stop plate 40 is fitted over the shaft between the escapement gear 39 and the ratchet gear 41. This provides clearance between gears (39 and 41 ) and prevents the ratchet pawl 42 from engaging the ratchet gear 41 when not in use. The tooth profile of the ratchet gear 41 allows the ratchet pawl 42 to increment the ratchet gear 41 around, and then freewheel back in the opposite direction. A ratchet lever 43 is mounted above the ratchet gear 41 and a bush 44 and washer 45 placed over the shaft 34. The ratchet lever 43 provides mounting for the ratchet pawl 42 and connection to the ratchet hydraulic actuator assembly which comprises a piston 46 and cylinder 47. The ratchet hydraulic actuator assembly moves the ratchet pawl 42 around the ratchet gear 41. The closed circuit hydraulic system design enables every pump of the handle grip 10 on the control bar to move the piston 46 out of the cylinder 47. Releasing the handle grip 10 allows the piston 46 to be pulled back into the cylinder 47 by a spring (not shown). This allows the main escapement 48 and slave escapement 49 to ratchet around the escapement gear 39. One of the escapements (48 or 49) engages the escapement gear every half tooth of turn. The main and slave escapements (48 and 49 respectively) are connected by an escapement control lever 50. This pivots on the slave escapement 49, and freely runs through a guide 51 which pivots on the main escapement 48. An escapement release lever 52 pushes on the escapement control lever 50 to break the engagement of the escapements with the

escapement gear. The mechanism ensures the slave escapement 49 is disengaged before the main escapement 48. This allows release of half to 1.5 teeth per actuation. The escapement release lever 52 is actuated by the release hydraulic actuator assembly, which comprises piston 53 and cylinder 54. This circuit functions in the same way as the ratchet hydraulic actuator assembly described above. The winch mechanism 9 includes a safety release mechanism comprising a safety release lever 55 and a safety release latch 56. When actuated, the safety release mechanism allows both escapements (48 and 49) to swing clear of the escapement gear 39, effectively allowing the pulley 33 to freewheel. The safety release mechanism is activated by operation of an external hand lever (not shown). In some other embodiments an auxiliary cable control (not shown) may be used.

An operator can use this adjustment mechanism to adjust the effective length of the leading edge control line 6 during flight by operating the handle grip 10 to wind-in the leading edge control line or to wind it out by operating the handle grip 11. The winch mechanism is configured such that the same amount of line is wound in with each complete stroke of the handle grip 10. These adjustments may enable an operator to adjust the effective length of the leading edge control line over a greater range of adjustment than would be possible by movement of the control bar alone. This may overcome the problem of adjustment being limited to the length of reach of the operator. Furthermore, the adjustment may be carried out during flight, overcoming the problem with prior art pulley adjustments which can only be done when the kite is not in flight. These advantages may lead to an operator being able to maintain the desired trim of the kite wing over a much wider range of conditions than is currently possible.

An adjustment mechanism for in-flight adjustment of a control line of a traction kite according to another embodiment of the present invention is generally indicated by arrow 57 in Figure 7. The components of the adjustment mechanism 57 in this embodiment are shown schematically in an exploded view in Figure 8.

In this embodiment the trailing edge control lines, 3 and 4, are adjusted using a winding mechanism in the form of a helical rotary hydraulic actuator contained within the control bar 58. The helical rotary hydraulic actuator is described in more detail below. In general the leading edge control line 6 (not shown in Figures 7 and 8) is held at a constant length when using this embodiment. The leading edge control line passes through the rope guide 59 which fits around the centre of the control bar 58, thus freeing up space in the interior of the control bar to be used to house the components of the helical rotary hydraulic actuator. The leading edge control line is looped through the rope guide such that one section of the line passes over the top and one section below the control bar. This arrangement may help to counter any turning moment created by the trailing edge control lines as they are wound in or out.

The helical rotary hydraulic actuator includes an activation device in the form of two levers formed as handle grips 60 and 61. The handle grips are located on opposite sides of the centre of the control bar 58 at locations corresponding to a usual hand position of an operator. The handle grips 60 and 61 are pivotally mounted to the control bar by pivots 62 and 63 respectively. In the embodiment shown in Figures 7 and 8, the right hand handle grip (60) activates the hydraulic actuator to wind in the trailing edge lines 3 and 4. The left hand handle grip (61 ) activates the hydraulic actuator to wind out the trailing edge lines 3 and 4.

The helical rotary hydraulic actuator is activated by an operator operating one or other of the handle grips (60, 61 ) attached to the control bar 61. As either handle grip 60 or 61 is activated it moves a power piston (64 or 65 respectively). The pressure exerted by the handle grips 60, 61 can be adjusted by use of adjusting pins, 66 and 67 respectively, which are threaded into the power pistons 64 and 65.

The helical rotary hydraulic actuator includes an hydraulic cylinder which, in this embodiment is formed by a section 68 of the control bar 58. In operation the hydraulic cylinder 68 is filled with oil.

A shaft, generally indicated by arrow 69, is located inside the hydraulic cylinder 68 and supported at each end by bearings (70 and 71 ). The shaft 69 includes a section having a helical spline 72 formed on the external surface. The bearings (70 and 71 ) are of an angular contact type and provide both linear and radial support for the shaft 69 and the hydraulic cylinder 68.

A spool, in the form of a pulley (73, 74) is attached to each end of the shaft 69. The pulleys, 73 and 74, are attached to the trailing edge control lines 3 and 4 respectively. Rotation of the shaft causes both pulleys to move by the same amount at the same time, and therefore to wind in or wind out the trailing edge control lines in the same manner (the direction of rotation depending on which handle grip is activated). A piston 75 fits over the shaft 69 and inside the hydraulic cylinder 68. The internal and the external surfaces of the piston 75 are cut with a helical spline. One end of the piston seals on an un-splined portion 76 of the shaft 69 and the internal wall of the hydraulic cylinder 68.

A stationary helical sleeve 77 is fitted around the piston 75 and is fixed to the wall of the cylinder 68 to keep it from rotating inside the cylinder. The stationary helical sleeve has an internal helical spline having a complementary thread to the helical spline on the exterior surface of the piston 75. As one or other side of the piston 75 is pressurised (by activation of the handle grip (60, 61 ) it will move in a linear direction (towards the lower pressure side) along the cylinder 68. This causes the piston 75 to rotate due to it being meshed with the spline inside the stationary helical sleeve 77.

The spline on the inside surface of the piston 75 is meshed with helical spline on the section 72 of shaft 69, so the shaft 69 rotates as the piston 75 rotates. This causes the pulleys (73 and 74), which are fixed to the end of the shaft 69, to turn, thus winding the control lines in or out. A guide sleeve 78 provides guidance for the piston 75 and prevents the thin wall section of the piston 75 from bulging. It also captures the outer race of the bearing 71.

A manifold (79 and 80) is attached to each end of the hydraulic cylinder 68. The manifolds are used to control the flow of hydraulic fluid. Each manifold (79 and 80) provides a relief path for the fluid on the non pressurised side of the piston 75 and it controls the power piston's (64 and 65) ability to pressurise the system. It has a circuit to allow the piston 75 to draw hydraulic fluid into the pressure side from the reservoir (81) connecting the manifolds.

Depression of one of the handle grips (60 or 61 ) moves the respective power piston (64 or 65) until it closes over an intake port in the cylinder of the manifold (79 or 80). Once the port is covered the system pressurises until the power piston (64 or 65) reaches the limit of its travel.

When the handle grip (60 or 61 ) is released the power piston (64 or 65) creates a vacuum in the pressure side. This lifts a check ball (82 or 83) from its seat and allows fluid to be drawn in from the reservoir (81 ). As the power piston (64 or 65) returns to its start position the cylinder of the manifold (79 or 80) fills with fluid ready to be reactivated.

The reservoir 81 is used to store the extra hydraulic fluid required by the system and to provide a link between the in and out circuits of the system to allow fluid to travel between the two circuits. The adjusting pin (66 and 77) allows the total travel of the handle grip (60 and 61) to be adjusted to suit the individual user. A ball bearing (84 and 85) provides a bearing surface for smooth movement between the handle grip and the adjusting pin. Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims.

Claims

WHAT WE CLAIM IS:

1. A method of adjusting a wing of a traction kite during flight, the kite including a control bar connected to the wing, the method including the step of: operating an activator located on the control bar to activate an actuator configured to adjust a control line connected to the wing wherein the actuator includes an hydraulic circuit.

2. A method of adjusting a wing of a traction kite during flight as claimed in claim 1 wherein the step of operating the activator activates the actuator to adjust a trailing edge control line.

3. A method of adjusting a wing of a traction kite during flight as claimed in either one of claims 1 or 2 wherein the step of operating the activator activates the actuator to adjust two trailing edge control lines.

4. A method of adjusting a wing of a traction kite during flight as claimed in claim 3 wherein both trailing edge control lines are adjusted at substantially the same time.

5. A method of adjusting a wing of a traction kite during flight as claimed in either one of claims 3 or 4 wherein both trailing edge control lines are adjusted by substantially the same amount.

6. A method of adjusting a wing of a traction kite during flight as claimed in claim 1 wherein the step of operating an activator activates the actuator to adjust a leading edge control line.

7. A method of adjusting a wing of a traction kite during flight as claimed in claim 6 wherein activating the actuator operates a winch assembly connected to the leading edge control line.

8. A method of adjusting a wing of a traction kite during flight as claimed in any one of claims 1 to 7 wherein the step of operating the activator includes moving a lever mounted on the control bar.

9. A method of adjusting a wing of a traction kite during flight as claimed in claim 8 wherein the lever is connected to a piston.

10. A control line adjustment mechanism for in-flight adjustment of a control line connected to a wing of a traction kite, the kite including a control bar connected to the wing, the mechanism including: a winding mechanism configured to attach to the control line; and an actuator configured to activate the winding mechanism; characterised in that the actuator is activated by an activator incorporated into the control bar wherein the actuator includes an hydraulic circuit.

11. A control line adjustment mechanism as claimed in claim 10 including a first and a

second activator incorporated into the control bar.

12. A control line adjustment mechanism as claimed in claim 11 wherein the first and

second activators are spaced apart on the control bar, so that at least one activator is in the vicinity of a normal hand hold for each hand of an operator.

13. A control line adjustment mechanism as claimed in either one of claims 11 or 12 wherein the first activator is operated to activate the hydraulic actuator to wind in the control line.

14. A control line adjustment mechanism as claimed in any one of claims 11 to 13 wherein the second activator is operated to activate the hydraulic actuator to wind out the control line.

15. A control line adjustment mechanism as claimed in any one of claims 10 to 14 wherein the activator includes a lever.

16. A control line adjustment mechanism as claimed in any one of claims 10 to 15 wherein at least part of the hydraulic circuit is incorporated into the control bar.

17. A control line adjustment mechanism as claimed in any one of claims 10 to 16 wherein the winding mechanism includes a spool attached to the control bar.

18. A control line adjustment mechanism as claimed in claim 17 wherein the spool is

configured to attach to a trailing edge control line.

19. A control line adjustment mechanism as claimed in either one of claims 17 or 18 wherein the actuator includes a helical rotary hydraulic actuator configured to rotate the spool.

20. A control line adjustment mechanism as claimed in any one of claims 10 to 16 wherein the winding mechanism includes a winch assembly.

21. A control line adjustment mechanism as claimed in claim 20 wherein the winch

assembly is connected to a leading edge control line.

22. A control bar including a control line adjustment mechanism as claimed in any one of claims 10 to 21.

23. A method of adjusting a wing of a traction kite during flight substantially as described in the accompanying description.

24. A control line adjustment mechanism substantially as described and as illustrated in the accompanying description and drawings.