GB2394907A - Ram-air traction kite - Google Patents

Abstract

A dual skin ram-air aerofoil traction kite comprises a series of linked chambers a, b, c, d, e, each having an upper and lower skin and separated by aerofoil section ribs 6. A limited number of cells are filled by air inlet valves 1, with internal baffles 5 which allow the whole structure to be filled and to maintain internal pressure. The one way valves 7 restrict the entry of water to the structure, while water egress valves 8 and debris egress valves 9 allow water and debris to be removed from the cells, allowing the kite to be relaunched from the water surface. Bridle lines(4 fig 2) enable the kite to be steered and a safety line (13 fig 2) enables the kite to land when required.

Description

Title: Water launchable Ram-air Traction Kite.

Description:

This invention relates to the activity of Traction Kiting and Kite Surfing and it outlines a traction kite that can be launched from the surface of a body of water.

A traction kite is a kite that is so designed to harness the wind and be powerful enough to pull a person along the surface of either land or water, with or without the aid of a suitable vehicle. This "Water Launchable Ram-air Traction Kite" will herein be identified as "kite" or "traction kite". The person controlling the kite will herein be identified as the "pilot".

Traction kiting is the activity of using a powerful kite to pull a person along a surface, with or without a suitable vehicle. The surface may be land or water (the activities are so named as "traction kiting" or "kite surfing"). The traction kite gains its power from the wind blowing over its surface.

The Traction Kite and F,xtreme Sports Industries need a way in which to take traction kiting to the water. This enables people to be pulled along by kites through or on the water, with or without appropriate watercraft, in the same manor as they are pulled along the ground in sports such as "para-karting", "Class 8 Land-yachting" or"Kite-buggying".

Most traction kites meet with problems when they land or crash on water. The kite must be able to be flown safely and generate enough power to pull a person through or on the water (with or without a watercraft), that can be safely landed and re-launched from the water's surface and that will collapse, or otherwise come to rest, when the kite is released or a safety line is pulled by the Pilot.

Essential Features: A ram-air aerofoil traction kite, comprising a series of linked chambers of aerofoil section shape, separated by "aerofoil section ribs" (6) and each having an "upper skin" (2) and a "lower skin" (3). The kite comprises jointly "air-inlet valves" (l), "internal bames" (5) and "one-way valves" (7), in a limited number of cells to allow the entry of air to inflate the whole kite (Figure 1.) whilst reducing the entry of water. The kite also includes "water egress valves" (9) and "debris egress valves" (8) for the purpose of water and debris drainage. The structure of the kite comprises dual skin outer surfaces (2 and 3), internal "aerofoil section ribs" (6) and uses reduced external "bridle lines" (4 and 13) to control the kite thereof and to help maintain the kites shape.

Detailed Description:

This kite is described further and in more detail below: A rarn-air aerofoil traction kite, comprising of dual skin outer surfaces (2 and 3) and divided internally by many "aerofoil section ribs" (6), that maintain the kite's shape and internal air pressure. The kite also comprises a small amount of external "bridle lines" (4 and 13) to control the kite thereof and to maintain the kite's shape. The kite has the ability to be launched, equally, from the surface of

the water or from the land. The working structure of the kite comprises "air-inlet valves" (1) and "one-way valves" (7) for the purpose of allowing the entry of air to inflate the kite, "water egress valves" (9) and "debris egress valves" (8) for the purpose of water and debris drainage and "Internal Baffles" (5) to allow equal internal air pressure.

The general construction of this kite is the same as any ram-air aerofoil traction kite. That is the "aerofoil section ribs" (6) are sewn to the "lower skin" (3) the valves are all sewn in place and the "upper skin" (2) is sewn to the upper edges of the "aerofoil section ribs" (6). The trailing edge and the leading edge are sewn closed, with the exception of the "air-inlet valves" ( 1), which contain a gauze cover to allow the entry of air. These are sewn into the leading edge. "Bridle lines" (4) are then sewn to the underside of the "lower skin" (3) in an arrangement that allows the "bridle lines" (4) on the left hand side to be joined together but separated from the "bridle lines" (4) on the rights hand side, which are also bound together. This will allow for Pilot control of the direction of the kite. The "Safety line" (13) is attached to the centre only, ofthe underside of the "lower skin" (3), in the same manor that the "bridle lines" (4) are attached. The "safety line" (13) is used to control the power output of the kite.

The difference in this invention from any other traction kite is the way in which the air is allowed inside the kite and water is stopped from entering, also the way in which any water inside the kite is removed. This is effected by use of leading edge valves and baffles as well as internal baffles and egress valves. These items use various types of gauze and flexible panels. This is described further below.

This invention is a rarn-air aerofoil traction kite. That is; it is a double skin (2 and 3) aerofoil that uses an "aerofoil section rib" (6) as it's cross-sectional shape and allows the entry of air through "air-inlet valves" ( 1) in the Leading Edge (front) to inflate the kite to it's full shape. It has a single skin, of a flexible material, on the upper area (2) attached to the top edge of the internal "aerofoil section ribs" (6), and a single skin, of a flexible material, on the lower area (3) of the kite, attached to the lower edge of the internal "aerofoil section ribs" (6). These many internal "aerofoil section ribs" (6) define the aerofoil shape and divide the kite into many internal cells. These many separate internal cells, divided by the "aerofoil section ribs" (6), have only a limited number of "air-inlet valves" ( I) on the Leading Edge. This reduces the risk of water gaining entry to the interior of the kite. This is the first way in which this kite reduces water entry. The remainder of the internal cells are fed air pressure via openings in the internal "aerofoil section ribs" (6), via "one-way valves" (7), to maintain the air-pressure within the cells.

Once the kite has gained its correct aerofoil shape, the wind acts over the kite's surfaces, producing 'lift' on the upper surface (2). Due to the exact shape of the aerofoil section, this kite produces more lift than drag, and therefore has enough power to fly under its own weight and produce enough power to pull a person (the Pilot), with or without a suitable vehicle, along a surface of either land or water.

Each traction kite built to this specification, depending on its size may have

approximately twenty internal cells. But approximately only four of those cells will have the "air-inlet valve" (1), "internal baffle" (5) and "water egress valve" (9) present. These cells are referred to as "airinlet cells" (c). Figure 5 shows an image of an "air-inlet cell" (c), clearly showing the approximate position of each valve assembly. Each "air-inlet cell" (c) will feed several other cells as well as itself. The other cells to be fed by the "air-inlet cell" (c) will be set out equally on either side of that cell. But this section, of several internal cells, is closed-off from the rest of the traction kite. No air is able to gain access to any other part of the kite from this particular "air-inlet cell" (c). This segregation reduces the occurrences of luffmg.

Note: "Luffing" is the lack of air pressure in a sail or kite. It stops the sail/kite from producing enough power or traction.

On the "air-inlet valves" (1) there is an elliptical "gauze panel" (10), fixed to the Leading Edge, to stop the majority of water and debris (sand, seaweed etc) from entering the traction kite's interior. This is the second way in which the traction kite reduces water entry. It also reduces the speed at which any water can enter the kite.

Immediately behind the "gauze panel" ( 10), and fixed at both ends to the Leading Edge of the traction kite, is a solid waterproof "fabric baffle" (11) which covers the elliptical air-inlet "gauze panel" (10) with an inverted curve shaped panel.

This panel covers approximately 90% of the "gauze panel" (10). As the wind blows, it moves the curved "fabric baffle" (I 1) aside to gain access to the interior of the kite but when too much air pressure, or water pressure, is evident inside the traction kite then the curved "fabric baffle" (11) is pulled taught across the "gauze panel" (10) opening, reducing the entry of either water or air. This is the third way in which the traction kite reduces water entry.

When air is blown into the traction kite, an "internal bame" (5) redirects the air through the "one-way valves" (7) (in the "aerofoil section ribs" (6)) to feed the air pressure in the other cells. These other cells do not have any "air-inlet valves" (1) or "water egress valves" (9) in them. They are closed cells. This is another aspect of the kite that allows it to land on the surface of the water and still be able to launch and fly.

If any water has managed to gain access into one of the few "air-inlet cells" (c) this will also hit the "internal baffle" (5) and will be redirected to the rear of the kite, due to gravity and baffle position, where a small opening (the "water egress valve" (9)) will drain the water away directly. Thus, any added weight due to water entry is greatly reduced as it can only get into 'one' of many cells, and is immediately removed from the kite. Even if one of the inlet cells were completely flooded it would only reduce the kite's pressure capabilities by 5%. Obviously water is very heavy and the kite can not fly with too much water inside it. But as long as the kite can remain with 50% internal airpressure, then it can rise from

the surface and drain the water, lessening it's weight and becoming ready for re-

launch. in the Trailing Edge (back), of "air-inlet cells" (c) only, the kite has "water egress valves" (9). The "water egress valves" (9) have no gauze but are made of a solid waterproof fabric covering, attached to the underside of the "lower skin" (3) of the kite by way of sewing on three sides with the fourth, facing aft, held in place by "Velcro fastening" (12). This allows the Pilot to set the required egress aperture between: allowing water quick egress and maintaining air-pressure, by adjustment of the "Velcro fastening" (12). It is also used, when the kite is at rest, to remove debris and clean the interior of the kite.

This is part of the way in which this kite is able to land on the surface of the water and be able to launch and fly.

There are also gauze covered "debris egress valves" (8) placed at the Trailing Edge (back) of each "aerofoil section rib" (6) that has a "oneway valve" (7) in.

This is to ensure the easy removal of any debris (sand, seaweed etc) that may have entered the kite.

The "debris egress valves" (8) are covered with much denser gauze than the "air-

inlet valves" (1) in the Leading Edge. This is to ensure and maintain the cell internal air-pressure, whilst allowing water to drain easily.

Example Layout: If the kite is constructed using 20 internal cells, then the "one-way valves" (7) and "debris egress valves" (8) would be contained in internal "aerofoil section rib" (6) numbers: 2,3,4,5,7,8,9, 10,12,13,14,15,17,18,19 and 20 but not in internal "aerofoil section rib" (6) numbers: 1,6,11,16 or 21 (rib numbers counted from left to right).

This arrangement keeps the cells together in small groups, but separates them from the other cell groups in the rest of the kite.

Cell Group Example: Internal cells 'a', 'b', 'c', 'd' and 'e' (see Figure 12) are kept separate from all of the other internal cells and cell groups. The cell labelled 'c' is the "air-inlet cell" (c) and cells labelled 'a', 'b', 'd' and 'e' are all closed off from the outside ofthe kite and closed off from other cell groups within the kite. These four cells are only fed from cell 'c'. l his segregation also reduces the risks of 'luffing'.

The construction material of the kite's shell items (2, 3, 5, 6, 7, 9 and 1 1) is a lightweight flexible rip-stop waterproof fabric. The outer shape ("Plan View") of the kite is bi-elliptic, with a very pronounced rounded leading edge and a slightly less pronounced rounded trailing edge. This aids the kite when it is on the water's surface, it will rotate to the correct upward facing position as the wind acts against its surface, ready for re-launch.

Looking directly at the Leading Edge of the kite ("Front Elevation"), the kite dips down at the outer edges, allowing it tracking capabilities without the need for external fins.

The kite's shape is held by the use of "bridle lines" (4) attached to the underside of the kite's "lower skin" (3), by means of knotted line or similar, that attach via a secondary bridle to the flying lines in the same manner. The flying lines attach in the same manner to the handles or control-bar or other control method (herein identif ed as "control method"), which the Pilot uses to control the direction and power of the kite.

An extra line is also attached to the control-method in the same manner; this is the "Safety line" (13). The other end of the extra line is attached, via another bridle, to the centre of the underside of the "lower skin" (3) of the kite, in the same manner as the other "bridle lines" (4). When the Pilot pulls the "Safety line" (l 3) it in turn pulls the centre of the kite forwards. This shape change of the kite results in the reduction of power (or 'traction') generated by the kite. The "Safety line" (13) can be pulled to reduce the power to such a degree that the kite will de-

power enough to land and no-longer give traction to the Pilot.

Upon release of the "Safety line" (13) the kite returns to it's correct shape and is ready for re-launch from the surface of the water or from the ground.

In two-line configuration, steering (or control) of the kite is effected by pulling on the right flying line to make the kite turn to the right. Equally, by pulling on the left flying line, the kite will turn to the left. For the sake of clarity, the flying lines and control method are not shown in any of the drawings, as they do not make up an integral part of this invention.

The "bridle lines" (4) also have an adjustment line attached to the two primary bridle lines, right and left. This adjustment alters the "angle of attack" of the kite and thus chariges the flight characteristics of the kite from fast to slow; it also changes the amount of power the kite can produce. The "bridle lines', (4) may further be split into four lines for a finer adjustment of the power output of the kite. In the four-line version of this kite, the upper primary bridle attaches to the secondary bridle, which in turn attaches to the upper flying lines (control lines).

The lower primary bridle attaches directly to the lower flying lines (power lines) without the need for a secondary lower bridle.

These lower flying lines are used to control the power output of the kite more accurately and offer a finer adjustment of such, without the need of "Safety line" (13) adjustment. The upper flying lines are used to control the direction ofthe kite in the same manner as in the two-line configuration.

\ The same "Safety line" (13) is used in both the two-line and the fourline configurations. It is unchanged by their usage and retains the ability to reduce the power output to such a degree that the kite depowers and looses traction.

List of drawings Figure 1. Overview.

This image shows the outer shape of the aerofoil traction kite. The "bridle lines" (4) have been removed for the sake of clarity.

Figure 2. Front Elevation.

This image shows the front of the kite. The "bridle lines" (4) and the "air-

inlet valves" ( 1) can be seen. The 'dip' of the outer edges can also be seen. Figure 3. Side Elevation.

This image shows the chord curvature of the kite from the Leading Edge to the Trailing Edge. The side view of the primary "bridle lines" (4) can be seen. Figure 4. Plan View.

This image shows the overall shape of the kite from above. It also shows the "internal baffles" (5), internal "aerofoil section ribs" (6) and valves (I and 9) from above.

Figure 5. Air-inlet Cell.

This image shows one of the four air-inlet cells (c). The "air-inlet valve" (1), "one-way valves" (7), "aerofoil section ribs" (6), "internal baffle" (5), "water egress valve (9) and "debris egress valves" (8) can be seen. The upper skin (2) and lower skin (3) can also be seen.

Figure 6. Air-inlet Valve.

This image shows the "air-inlet valve" (1) in orthographic view, with the air-inlet "gauze panel" (10) and the inlet "fabric baffle" (11) attached.

Figure 7. Air-inlet Valve - Isometric View.

This image shows the "air-inlet valve" ( l) in isometric view, with the air-

inlet "gauze panel" (10) and the inlet "fabric baffle" (11) attached.

Figure 8. Inner Same.

This image shows the "internal baffle" (5) shape, used to deflect air and water. Figure 9. One-way Valve - Isometric View.

This image shows the "one-way valve" (7) from the 'lee' side of the internal "aerofoil section rib" (6). The image shows the valve as air is passing through it in one direction.

Figure 10. One-way Valve - Orthographic View.

This image shows the "one-way valve" (7) in an orthographic view, together with the attachment point lines.

Figure 11. Debris Egress Valve- Orthographic View.

This image shows the "debris-egress valve" (8), which is situated in the internal "aerofoil section ribs" (6) in the "air-inlet cells" (c), at the aft end of the panel. It is made from a dense gauze mesh. The image shows the "debris egress valve" (8) shape in orthographic from the side.

Figure 12. Closed Cell System.

This image shows the closed cells (a, b, c, d and e) that this design employs in order to maintain the air pressure and stop airflow between the internal sections of the kite. This image shows the "air-inlet valve" (1), "one-way valves" (7), "internal baffles" (5), internal "aerofoil section ribs" (6), "debris egress valves" (8) and "water egress valves" (9). The "upper skin" (2) and extra cells have been removed for clarity.

Figure 13. Debris Egress Valve - Isometric View.

This image shows the "debris-egress valve" (8), which is situated in the internal "aerofoil section ribs" (6) in the "air-inlet cells" (c), at the aft end of the panel. The image shows the "debris egress valve" (8) in position in the internal "aerofoil section rib" (6) in isometric view.

Figure 14. Water Egress Valve - Orthographic View.

This image shows the "water-egress valve" (9) in orthographic view. The "water egress valve" (9) is situated in the "lower skin" (3) in the "airinlet cells" (c), at the aft end of the panel. The image shows the position of the attachment lines.

Figure 15. Water Egress Valve - Isometric View.

This image shows the "water-egress valve" (9) in isometric view. The image shows the "lower skin" (3), "debris egress valve" (8), "aerofoil section ribs" (6) and "water egress valve" (9).

Claims (13)

q Claims:

1. A ram-air aerofoil traction kite, comprising jointly "air-inlet valves" (1), "internal baffles" (5) and "one-way valves" (7) in limited cells to allow the entry of air to inflate the whole kite (Figure 1 and 12) whilst reducing the entry of water, including "water egress valves" (9) and "debris egress valves" (8) for the purpose of water and debris drainage, also comprising dual skin outer surfaces (2 and 3) and divided by internal aerofoil-

sectioned ribs (6) and reduced external bridle lines (4 and 13) to control the kite thereof and to maintain the kites shape.

2. A kite as claimed in Claim 1 wherein air-inlet means are provided by the limited number of "air-inlet valves" ( 1) in the Leading Edge to increase internal air pressure enough to inflate the kite to it's required shape, but reduce the entry of water.

3. A kite as claimed in Claim 2 wherein the "air-inlet valves" (1) use a gauze panel (10) and waterproof fabric baffle panel (11) to reduce the entry of water but allow the entry of air.

4. A kite as claimed in Claim 2 or Claim 3 wherein the number of "airinlet valves" (1) (in the "air-inlet cells") are fewer than the amount of internal cells.

5. A kite as claimed in Claim 2 wherein a means to deflect air into the closed-off internal cells and deflect water directly to the "water egress valves" (9) is provided by way of an "internal baffle" (5) only in the "air inlet cells".

6. A kite as claimed in Claim 4 or Claim 5 wherein the internal cells are closed off from the outside of the kite, with the exception of the "airinlet cells".

7. A kite as claimed in all preceding claims wherein the internal aerofoil ribs (6) contain a single "one-way valve" (7) and "debris egress valves" (8).

8. A kite as claimed in all preceding claims wherein the Trailing Edge of the kite uses adjustable "water egress valves" (9).

9. A kite as claimed in Claim 1 wherein the outer shape is low aspect ratio bi-

elliptic and dips down at the outer edges.

10. A kite as claimed in Claim 9 wherein the shape of the kite is held inplace by a reduced primary and secondary bridle (4) assembly attached to the lower surface (3) of the kite, using adjustable lines allowing for changes in the "angle of attack" of the kite.

11. A kite as claimed in Claim 10 wherein the ability to gradually depower is provided by the "Safety Line" (13).

12. A kite as claimed in Claim 11 wherein the ability to completely deflate is provided by the "Safety Line" (13).

13. A water re-launchable ram-air aerofoil traction kite substantially as herein described and illustrated in the accompanying drawings.