WO2005058698A1

WO2005058698A1 - Towing winch apparatus for paragliders and hang-gliders

Info

Publication number: WO2005058698A1
Application number: PCT/DK2004/000868
Authority: WO
Inventors: John Tvingsholm
Original assignee: Paraparts Holding Aps
Priority date: 2003-12-18
Filing date: 2004-12-16
Publication date: 2005-06-30
Also published as: EP1706317A1

Abstract

A towing winch apparatus for paragliders and hang-gliders (4,6) is provided which comprises a line (3) and a towing winch mechanism (5) adapted to apply tension to said line (3) during towing, where one end (15) of the line (3) is releaseably attached to the ground (16) during towing and the towing winch mechanism (5) is attached to the paraglider or hang-glider (4,6). In this way a towing winch apparatus is provided which is useable by a pilot (1) of a paraglider or hang-glider (4,6) without needing a helper on the ground (16). In addition, after the tow process, the pilot (1) of a paraglider or hang-glider (4,6) doesn't need to go back to the ground (16) in order to collect the towing winch mechanism (5).

Description

Towing winch apparatus for paragliders and hang-gliders

Field of the Invention

The present invention relates to a towing winch apparatus for paragliders and hang-gliders, said towing winch apparatus comprising a line and a towing winch mechanism adapted to apply tension to said line during towing.

Background of the Invention

Paragliders and hang-gliders use the effects of rising air to stay aloft. Typically rising air comes from thermal activity on the ground. The sun warms a patch of ground thereby heating the air overlying the ground. The warm air forms a bubble over this patch of ground. At some point this bubble of warm air breaks free and starts to rise. Such a bubble of warm air is typically called a thermal. Using the effect of such thermals, paragliders and hang-gliders can stay aloft for many hours and fly many hundreds of kilometers.

However, these thermals are first accessible once a paraglider or hang-glider is in the air. Paragliders and hang-gliders have no onboard power source with which to become airborne. They therefore need some sort of device to get them into the air before they can take advantage of the thermals.

Description of the Prior Art

A common solution to this problem is to use a powered device to "tow" a non-powered flying device, such as a paraglider or hang-glider, into the air. A common form of towing is to use a powered flying device. In this form of towing a non-powered flying device is attached to a powered flying device, such as a motor plane, via a long cable. The powered flying device pulls the non-powered flying device into the air. Once the two flying devices have reached a certain altitude, the non- powered flying device releases the cable and begins to fly on its own. The non-powered flying device now begins to descend slowly back to the ground, until a thermal is found which enables the non-powered flying device to stay in the air. This form of towing is very popular for sailplanes. However, a powered flying device such as a motor plane is rather expensive. In addition, the speed of a motor plane is too high to safely tow, for example, a paraglider. Therefore alternative solutions have been developed which are more economical and better suited to paragliders and hang-gliders.

These more economical solutions usually take the form of a ground based towing apparatus . One such ground based solution is to mount a line to a land based vehicle, such as a car, and the other line to a non-powered flying device. As the car drives along the ground, the non-powered flying device is towed into the air. With this solution it is necessary to have a large area upon which it is possible to drive a car.

Another ground based towing solution is a towing winch. A towing winch comprises a spool powered by a motor, typically a car engine. A cable is wound onto the drum as it turns. By attaching one end of the cable to a non-powered flying device, the non-powered flying device can be towed into the air as the cable is wound in. A typical towing winch assembly is shown in DE 3,537,264. Many other types of towing winch assemblies are available, another one being shown in DE 4,230,541.

The problem with towing winch solutions is that it is necessary for an operator to control the operation of the towing winch. Even if it were possible to use the winch alone, it would not be very useful because it would be undesirable to leave the towing winch assembly at the take-off site. In many cases, a non-powered flying device does not land at the same place it took off. This means that after the flight, the towing winch assembly would need to be picked up. In addition, a towing winch is a large and bulky machine, which must be maintained and stored when not in use.

Summary of the Present Invention

A first aspect of the present invention is to provide a towing winch apparatus as mentioned in the opening paragraph, which does not require a ground helper.

A second aspect of the present invention is to provide a towing winch apparatus as mentioned in the opening paragraph, which does not need to be collected after towing.

A third aspect of the present invention is to provide a towing winch apparatus as mentioned in the opening paragraph, which is compact and lightweight.

The new and unique way in which the present invention fulfills the above mentioned aspects is by providing a towing winch apparatus for paragliders and hang-gliders where one end of the line is releaseably attached to the ground during towing and the towing winch mechanism is attached to the paraglider or hang-glider. Since the towing winch mechanism is attached to the paraglider or hang-glider and not to the ground, the pilot can fully control the mechanism without there being need for a ground helper. In addition, since the mechanism is attached to the paraglider or hang-glider, the mechanism does not need to be collected after the flight. By releaseably attaching one end of the line to the ground, the towing winch mechanism can tow a paraglider or hang-glider up to a certain height at which point the line can be released from the ground allowing the pilot to fly away.

By the wording, "attached to the paraglider or hang-glider", is meant that during towing, the towing winch mechanism and the paraglider or hang-glider move together, thereby approximately following the same flight path. The term "attached" should be interpreted quite loosely. For example, within the scope of the invention, the towing winch mechanism could be attached to the pilot's harness since the pilot is attached to the paraglider or hang-glider.

The term "ground" should also be loosely interpreted. The term ground includes any objects, which could provide a suitable anchor from which to tow the paraglider or hang-glider into the air. Such items could include trees, large stones, etc.

One example application of the towing winch apparatus according to the current invention is to tow a paraglider pilot, where the towing winch mechanism can be mounted to the harness of the paraglider pilot.

In a preferred embodiment, the towing winch mechanism can comprise a spool attached to the line and a motor to rotate the spool. In order for the towing winch mechanism to be as compact as possible, the towing winch mechanism can comprise winding means to ensure that the line is wrapped onto the spool in an ordered manner. By using winding means, the spool with the line wrapped on it, fills less space than if the line is randomly wrapped on the spool. It should be mentioned that depending on the design of the spool and the type of line used, it is not always necessary to use mechanical winding means to get the line to wrap onto the spool neatly.

In order to increase the torque applied to the spool, the towing winch mechanism can further comprise a speed reducing transmission between the spool and the motor. In this way, small, low torque, high speed motors can be used. The speed reducing transmission reduces the speed and increases the torque. In a preferred embodiment of the towing winch mechanism, the towing winch mechanism can comprise a centrifugal clutch between the spool and the motor. In this way, the spool doesn't turn at low motor speeds. This allows the pilot to start the motor and get into the proper position without the spool turning. The towing winch apparatus can also comprise control means, which allow the pilot to directly control the operation of the towing winch mechanism during use. This allows the pilot to have full control over the towing process without their being a need for a helper.

One possible method of releaseably attaching the line to the ground is to attach a loop on the end of the line, which is then placed over a hook anchored to the ground. The geometry and the placement of the hook are arranged such that said loop slides off the hook before the paraglider flies over the hook. In this way, a very simple, low cost mechanism is provided for releaseably attaching the line to the ground.

In order to handle an emergency, the towing winch apparatus can be provided with cutting means, which allow the pilot to cut the line .

Brief Description of the Figures

The invention will be explained in greater detail below where further advantageous properties and an example embodiment are described with reference to the drawing, in which

Fig. 1 shows the prior art approach when towing paragliders into the air, and

Fig. 2 is a schematic representation seen from the side of an embodiment of the towing winch apparatus according to the invention used together with a paraglider. Description of a Preferred Embodiment of the Invention

Fig. 1 shows the prior art towing procedure for paragliders. The paraglider pilot 1 is attached to a towing winch mechanism 2 via a line 3. The procedure starts at point A with the paraglider pilot 1 standing on the ground, a distance from the towing winch mechanism 2. Once the pilot is ready, a ground helper starts the towing winch apparatus 2. The towing winch mechanism 2 begins to pull the paraglider pilot 1 towards itself by winding the line 3 up on a drum which is a part of the towing winch mechanism 2. As the paraglider pilot 1 is pulled towards the towing winch mechanism 2, the paraglider 4 generates lift and lifts the paraglider pilot 1 off the ground. As the paraglider 4 and its pilot 1 fly forward, the paraglider 4 lifts the paraglider pilot 1 further and further upwards, as can be seen at point B. At point C the paraglider pilot 1 is high enough and releases the line 3. Point D shows the paraglider pilot 1 freed from the line 3 and the line 3 falling back to the ground. A parachute attached to the end of the line 3 slows the descent of the line 3.

Fig. 2 shows a schematic representation of one embodiment of a towing winch apparatus according to the invention. In this case the towing winch apparatus is used as a towing apparatus for paragliders. In contrast to the prior art where the towing winch mechanism is attached to the ground, the current invention teaches that the towing winch mechanism 5 is attached directly to the flying device, in this case to the back of the harness 6 of a paraglider pilot 1. Note that due to the schematic nature of fig. 2, the frame of the towing winch mechanism 5 is not shown.

The towing winch mechanism 5 comprises a motor 7 and a spool

8. The motor 7 is connected to the spool 8 via a speed reducing transmission. The speed reducing transmission comprises a small sprocket 9 connected to the motor 7, a large sprocket 10 connected to the spool 8 and a chain 11 connecting the two sprockets 9,10. The small sprocket 9 is connected to the motor 7 via a centrifugal clutch 12. Many other types, of speed reducing transmissions are also possible. These include belt/pulley transmissions, hydraulic transmissions, etc.

In the current embodiment, a control device 13 is connected to the motor via a cable 14. The control device 13 in this case is used by the pilot 1 to control the speed of the motor 7. Due to the presence of the centrifugal clutch 12, at low motor speeds the clutch 12 is not engaged and the motor 7 can turn without the spool 8 turning. When the pilot 1 increases the motor 7 speed, the centrifugal clutch 12 engages and the spool 8 begins to turn. By regulating the speed of ' the motor 7 via the control device 13, the pilot can engage or disengage the clutch, thereby controlling the amount of tension in the line 3. In this way, the pilot has full control over the operation of the towing winch mechanism.

The main purpose of the control device is for the pilot to have direct control over the towing winch mechanism without the need for a helper. The control device could control various aspects of the towing winch ' mechanism in many different ways as will be obvious to a person skilled in the art. In addition, many different forms of the control device can be used. Besides mechanical solutions, digital solutions, such as a joystick, coupled to a micro controller which controls an electro/mechanical actuator mounted on the towing winch mechanism, are also possible.

A line 3 is attached to the spool 8. As the spool 8 turns, the line 3 is wrapped onto the spool 8. Since the motor 7 and the spool 8 are connected the speed at which the line 3 is pulled into the towing winch mechanism 5 can be controlled by controlling the speed of the motor 7. The free end 15 of the line 3 is releaseably attached to the ground 16 at a distance from the paraglider 4. In the embodiment shown in fig. 2, a loop 18 is attached to the free end 15 of the line 3 and placed over a hook 17 fixed in the ground 16. The hook 17 is formed such that when the line connected to said hook 17 pulls from an angle which is greater than a predefined angle, then the line slips off the hook 17. In fig. 2, the predefined angle is the approximately the normal of the bent portion of the hook. The hook 17 need not be formed as a typical hook. Two other examples are a straight rod set in the ground at an angle and a straight rod with a friction coating holding the loop 18 until the line 3 pulls from an angle which pulls the loop 18. off the hook 17.

Once the paraglider 4 and the pilot 1 are in position and the free end 15 of the line 3 is releaseably attached to the ground 16 at a distance from the paraglider 4, the paraglider pilot 1 starts the motor 7 via its pull start 19. Due to the centrifugal clutch 12, the spool 8 does not turn at low speeds of the motor 7. When the paraglider pilot 1 is ready, the paraglider pilot 1 increases the speed of the motor 7, via the control device 13. As the speed of the motor 7 increases, the centrifugal clutch 12 activates and the spool 8 begins to turn. As the spool 8 turns, the line 3 is pulled into the towing winch mechanism 5. Since the free end 15 of the line 3 is attached to the ground, the paraglider pilot 1 and the paraglider 4 are towed forwards, toward the place where the hook 17 is attached to the ground 16. As the paraglider 4 is pulled forward, it begins to generate lift thereby lifting it up into the air.

As the spool 8 winds up the line 3, the paraglider 4 is pulled higher and higher. As the paraglider 4 is pulled higher and higher, the angle between the ground and the line 3 increases. Due to the geometry and placement of the hook 17, once the line 3 reaches a certain angle to the ground 16, the loop 18 slides off the hook 17. It is important that the loop 18 has slid off the hook 17 by the time the paraglider 4 is about to fly over the hook 17. If the paraglider flies any more forward without the line 3 being released from the hook, then the line 3 will pull the paraglider 4 downwards. This is dangerous for the pilot 1 as the paraglider 4 will crash if it the line 3 isn't released from the ground attachment.

The free end 15 of the line 3 is then pulled the remaining distance into the towing winch mechanism 5. In order to keep tension on the line 3 so that the line 3 is not tangled as it is wound in, a small drogue parachute 20 is attached close to the free end 15 of the line 3.

In order to ensure that the line 3 is properly wrapped onto the spool 8, the towing winch mechanism, in this example embodiment, further comprises a winding mechanism 21. The winding mechanism 21 is of the kind commonly known from fishing reels and other winch assemblies where it is important that the line is properly arranged on the spool. The winding mechanism 21 comprises a cable guide head which moves back and forth along a shaft arranged parallel to the axis of the spool 8. The cable guide head guides the line 3 as it is wound onto the spool 8. The cable guide head can be made to move in many different ways. One common way is to use two counter-rotating drive shafts which take turns in driving the cable guide head. When the cable guide head reaches one side of the spool, the cable guide head switches from one drive shaft to the other. Due to the counter rotating nature of the drive shafts, by switching the cable guide head from one driven shaft to the other, the cable guide head begins to move in the other direction. The counter rotating shafts of the winding mechanism 21 are driven by a pulley and belt arrangement 22, which connects the winding mechanism 21 and the spool 8. Many other forms of winding mechanisms 21 are also possible, one example being a mechanism where the spool 8 moves back and forth along its axis while the line is held at a constant position.

Once the line 3 is pulled completely into the towing winch mechanism 5, the pilot 1 can stop the motor 7 and enjoy a silent flight. The towing winch mechanism 5 remains a part of the harness 6 of the paraglider pilot 1 even after towing. The extra weight of the towing winch mechanism 5, will not affect the paraglider pilot 1 significantly. Paraglider pilots often fly with ballast in order to increase their speed. The towing winch mechanism 5 therefore only acts as ballast.

In order to ensure that the line pulls from the front of the paraglider pilot 1 during towing, a set of pulleys 23 are arranged on the harness 6. In some cases, it would be beneficial to implement a rigid frame (not shown) between the pulleys in order to properly distribute the forces. A rigid frame would be useful during takeoff where there is not so much tension in the lines of the harness 6. However, it is not necessary for the pulleys to be rigidly connected to each other. In the example embodiment, the pulleys are connected to an articulated arm (not shown) . Each pulley is connected at one of the joints of the arm. The links of the arm between the pulleys are stiff. The first pulley is attached directly to the winch mechanism close to the spool 8 and the last pulley is connected to the risers of the paragliding harness via straps. This ensures that the tension is transferred properly to the paraglider and the harness. Since the arm is articulated, the arm can be freely moved in order to place the arm in a position which is comfortable for the pilot.

Using the towing winch apparatus shown in fig. 2, the paraglider pilot 1 can tow him/herself up to a desired altitude without any helper being necessary on the ground. In addition, the only thing left behind on the ground is the hook 17. The low cost of the hook 17 means that it can be left behind without a large expense for the pilot.

In case of an emergency, such as a situation where the loop 18 will not release from the hook 17, cutting means 24 are attached to the harness 6. The paraglider pilot 1 can at any time cut the line 3 with the cutting means 24 and thereby be released from the pull of the line. In fig. 2 a pair of cutting pliers 24 are attached to the harness 6. However, it would also be possible to use more advanced cutting means which would make it easier for the pilot 1 to cut the line 3.

In order to protect the towing winch mechanism 5 from damage, the towing winch mechanism is covered by a protective covering 25. In order to protect the paraglider pilot 1, the back of the harness 26 has built in protection for the pilots back.

The embodiment shown in Fig. 2 is just one of many different embodiments which are within the scope of the invention. One other example embodiment is a towing winch mechanism which attaches to the front of a harness of a paraglider pilot. Another example embodiment is a towing winch assembly which attaches to the frame of a hang-glider.

Many other types of devices to releaseably attach the free end 15 of the line 3 to the ground 16 are also possible. One example of such a releasing device is a remote control device (not shown) . A radio signal is sent from the pilot, via a radio transmitter carried by the pilot, when the pilot wishes to release. A radio receiver mounted at the ground receives the signal and activates a release which releases the line 3 from the ground. The release could be a latch which opens. It could also be a weak link which is burnt. Many different forms of releases are possible. By using the remote control device, the pilot has more control over the towing process. In addition, it is possible to use elements fixed to the ground such as trees or other large objects as anchors for the line 3.

Another method of releasing the ground attachment point is to build a release mechanism (not shown) on the free end 15 of the line 3 which is triggered by an impact force. The impact force could be generated by the paraglider pilot 1 dropping a small lead weight (not shown) which slides along the line 3. When the small lead weight reaches the release mechanism it crashes into the release mechanism causing it to open. This is a very simple and low cost release mechanism.

Claims

1. A towing winch apparatus for paragliders or hang-gliders (4,6) comprising, - a line (3 ) , and a towing winch mechanism (5) adapted to apply tension to said line (3) during towing, characterized in that, one end (15) of the line (3) is releaseably attached to the ground (16) during towing, and the towing winch mechanism (5) is attached to the paraglider or hang-glider (4,6).

2. A towing winch apparatus according to claim 1 characterized in that the towing winch mechanism (5) is mounted to a paragliding harness (6) .

3. A towing winch apparatus according to claim 1 or 2 characterized in that the towing winch mechanism (5) comprises a spool (8) attached to the line (3) and a motor (7) to rotate the spool (8).

4. A towing winch apparatus according to claim 3 characterized in that the towing winch mechanism (5) further comprises winding means (21,22) to ensure that the line (3) is wrapped onto the spool (8) in an ordered manner .

5. A towing winch apparatus according to claim 3 or 4 characterized in that the towing winch mechanism (5) further comprises a speed reducing transmission (9,10,11) between the spool (8) and the motor (7).

6. A towing winch apparatus according to any one of the claims 3 to 5 , characterized in that the towing winch mechanism (5) further comprises a centrifugal clutch (12) between the spool (8) and the motor (7) .

7. A towing winch apparatus according to any one of the claims 1 to 6 characterized in that the line (3) is releaseably attached to the ground (16) via a loop (18) placed over a hook (17) anchored to the ground (16), the geometry and the placement of said hook (17) being arranged such that said loop (18) slides off said hook (17) before the paraglider or hang-glider (4,6) flies over said hook (17) .

8. A towing winch apparatus according to any one of the claims 1 to 7 characterized in that the towing winch apparatus comprises control means (13,14) allowing the pilot (1) to control the towing winch mechanism (5) .

9. A towing winch apparatus according to any one of the claims 1 to 8 characterized in that the towing winch apparatus comprises means (24) for cutting the line.

10. A method of towing a paraglider or hang-glider (4,6) into the air comprising: attaching a towing winch mechanism (5) to the paraglider or hang-glider (4,6), said towing winch mechanism (5) arranged to apply tension to a line (3), releaseably connecting one end (15) of said line (3) to the ground (16) at a distance from the paraglider or hang-glider (4,6), - starting a motor (7) which is a part of the towing winch mechanism (5), applying tension to the line (3) via the towing winch mechanism (5), and releasing the line (3) from the ground (16) when the paraglider or hang-glider (4,6) reaches a certain position in relationship to the ground (16) .