US20050016437A1

US20050016437A1 - Craft for water sports

Info

Publication number: US20050016437A1
Application number: US10/858,577
Authority: US
Inventors: Martin Bishop
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-07-23
Filing date: 2004-06-02
Publication date: 2005-01-27
Also published as: GB0317168D0

Abstract

A water craft having a support arranged to float on water with a central axis arranged to lie generally perpendicular to the surface of the water. The support has a number of rowing positions arranged around the axis at or near the periphery of the support. Rowers in the rowing positions propel the craft around the central axis using oars. The craft is useful for training oarsmen.

Description

The present invention relates to a craft arranged to float on water, and to be propelled by users seated on or in the craft using oars or paddles. The craft is especially suited for use in training, for example for rowing, canoeing and dragon boating.
A problem when training for rowing, canoeing, dragon boating and the like is that it is generally necessary to provide a long stretch of water for the participants to row the craft. This may be difficult since such a stretch may not always be available, and also because the weather conditions may make it difficult or undesirable to train on any available stretch of water.
Even where training on a long stretch of water is possible, it may be difficult for a trainer or coach to monitor the training session since this requires the trainer or coach to remain close to the boat. This may require the trainer to be on a separate craft, such as a powered boat, or to move along beside the stretch of water, for example in a powered buggy, cycle or the like.
Accordingly, it is common to use land based training apparatus such as an ergometer. This has the disadvantage that it is not “real” rowing, and that it does not help promote rowing as a team.
According to the present invention, a water craft comprises a support arranged to float on water and having a central axis arranged to lie generally perpendicular to the surface of the water when the support is floating on the water, and including a number of rowing positions arranged around the axis at or near the periphery of the support, such that rowers in the rowing positions propel the craft around the central axis.
With the craft of the present invention, a number of rowers are able to propel the craft around the central axis, thereby allowing the craft to occupy generally the same position. Accordingly, the craft is ideally suited for training or use in limited spaces, for example in a lake or swimming pool, where other watercraft cannot be used.
In one example, the support is in the form of a ring for supporting the rowing positions. In this case, radial retaining arms, which could be rigid or in the form of ropes, wires or the like may be provided to connect the ring to a central ring The support ring is advantageously toroidal in shape to give buoyancy and to give positions for the rowers.
In a preferred example of the present invention, the support is in the form of a platform, preferably having a generally circular shape. In this case, the platform may be formed in a number of parts including a lower part arranged to float on the water, and an upper part on which the rowing positions are located. The parts may be formed, for example by moulding, using a composite material, such as glass reinforced polyester. Alternatively, the support may be formed as a single component. Where the single piece is hollow to enhance the buoyancy of the device, the component may be formed using rotational moulding techniques.
The platform may include hollow portions for increasing the buoyancy of the craft. Beneficially, the buoyancy of the craft may be adjusted. This is particularly useful where the craft is to be used by different numbers of rowers or rowers of different weight as it enables the craft to float at an optimum level on the water. Further, the ability to adjust the height may be advantageous in determining a preferred or optimum level for particular rowers. The buoyancy of the craft may be adjusted by providing a void on the underside of the craft to trap air under the craft, and including an opening through which the volume of air in the void may be adjusted. For example, air may be vented from the void to decrease the buoyancy of the craft. The opening may be selectively opened, for example being in the form of a bung, cap or valve. Alternatively or additionally, buoyancy may be increased by adding air or other gas to the void. This may be achieved using a compressor, such as a battery powered compressor, or using a source of compressed gas.
The craft may be made from various materials, however it is preferred that the craft is formed from polyethylene or other plastics material. Where the craft is formed from a plastics material, the parts of the craft can be moulded, for example by rotation moulding.
The craft of the present application may have any desired number of rowing positions. However, a preferred number of positions is four. This is preferred as it allows the craft to be formed at an acceptable size, and is useful as it corresponds to either two sets of a pair of rowers, a rowing four, or half a rowing eight—these being the normal crew sizes for rowing boats.
Each of the rowing positions is preferably configured similar to a rowing position of a conventional rowing boat, in particular including a seat arranged to slide along a slide track during the rowing action, and a footplate fixed to the craft to which the rowers' shoes are fixed, for example using a Velcro (Trade Mark) strap or other attachment means.
Each of the rowers will need to sit in the same direction so that they all drive the craft in the same rotational direction. In a preferred aspect of the present invention, the rowers' positions are adjustable to allow each of the rowers to reverse their position, for example each changing from a bow side position (in which the oars extend to the left of the rower) to a stroke side position (in which the oars extend to the right side of the rower). This is achieved by providing two sets of slides arranged generally perpendicular to each other for each rower's seat, and footwells for footplates similarly arranged generally perpendicular to each other. In this case, when the craft is to be switched from bow side to stroke side use, the seats and footplates can be moved from one position to the other. It will be appreciated that additional footplates may be provided in the alternative position to avoid the need to move the footplates. The removal of seats is conventional in rowing craft.
Especially where the craft has a large number of rowing positions, and therefore has a large size, it is preferred that radial restraints are provided between the centre of the craft and each of the rowers to prevent the rowers being forced outwardly due to circumferential forces during use.
It is preferred that the rowing positions are arranged equally around the axis. This helps ensure that the craft is balanced, and gives each rower the optimum space.
In a preferred example, the craft has an overall diameter of around 3 m, and the rowing positions are arranged around the central axis, spaced between about 0.6 m and 1.1 m from the axis.
Examples of the present invention will be described with reference to the accompanying drawings in which:
FIG. 1 shows a plan view of a first example of a craft according to the present invention;
FIG. 2 shows a view of a participant in the craft shown in FIG. 1;
FIG. 3 shows a partial cross-section of the craft of FIG. 1 showing different positions of the participants;
FIG. 4 shows a perspective view of the craft of FIG. 1;
FIG. 5 shows a plan view of an alternative example of a craft according to the present invention;
FIG. 6 shows a cross-sectional view of the craft of FIG. 5;
FIG. 7 shows the two parts forming the craft of FIG. 5;
FIG. 8 shows an enlarged view of the rigger used in the craft of FIG. 5; and,
FIG. 9 shows a partial cross-section of the craft of FIG. 5 including three users.
A first example of a craft according to the present invention is described with respect to FIGS. 1 to 4. In this example, the craft comprises a generally circular hull having a toroidal shape. A central ring 2 is provided, which is connected at the centre of the hull 1 by a series of ropes 3 or other supports. This maintains the ring 2 at the centre of the hull.
In the example shown in FIG. 1, there are sixteen rowing positions, at each of which is provided a seat and a footwell for the rower, and a rigger 4 for oars 5. It will be appreciated that fewer than sixteen positions may be provided. In a particularly preferred embodiment, four rowing positions are provided, these being provided equally spaced around the hull.
As shown in FIG. 3, each of the rowing positions includes a footwell 10 for the rowers' feet. As with conventional craft, a footplate may adjustably be provided within the footwell to which the rower's shoes can be attached, for example using Velcro straps or the like. Each rowing position also includes a seat 9 that is slidable, for example along runners, in a direction generally perpendicular to the footplate in the footwell. In accordance with conventional rowing technique, the seat 9 with rower 7 will move towards the footwell until the “catch” where the blade of the oar enters the water, and will slide away from the footwell during the drive part of the stroke to the finish position where the oar is lifted from the water, and then back towards the footplate during the recovery.
In use, all participants will sit in the same direction around the hull, namely with each rower facing generally towards the back of the rower in front. In this way, all rowers will row either bow side, namely with the oars extending to their left, or stroke side, namely with the oars extending to their right. However, as shown in FIG. 3, the rowers' positions are reversible to allow all participants to row either bow side or stroke side. In the example in FIG. 3, this is achieved by providing two footwells, one to either side of the seat. In this case, the seat may be removed from the slides and turned around if the seat is ergonomically shaped.
As shown best in FIG. 2, a radial restraint 8, for example in the form of a rope, may be provided with a harness 7 between the centre ring 2 of the craft and each rower. Since the craft may be propelled rotationally at a high speed, there will be a circumferential force on the rowers acting to force the rowers outwardly. This force can be overcome by the use of a suitable restraint. In this case, the harness is arranged to wrap around the chest of the rower and is attached to the rope at shoulder and waist height, thereby ensuring that this does not adversely affect the rower's arm movement during rowing.
Especially for craft of a large size, the toroidal circular hull may be formed in a number of parts that can be connected together when in use. In the example shown, the hull may be formed in four parts, each comprising a quadrant of a circle, these parts being attached at joints 6 by bolts or other suitable attachment means. The joints preferably also include a ceiling gasket to ensure that the hull remains watertight. In this way, the hull can be disassembled for ease of transportation.
A second example of a craft according to the present invention is described with reference to FIGS. 5 to 9. In this case, the craft is formed from a generally circular, rather than ring-shaped, hull as best seen from the plan view of FIG. 5 and the cross-sectional view of FIG. 6. In the example shown, four rowing positions are provided, equally spaced around the centre of the craft. Each rowing position includes a recess 20. The recesses are shown as a cross shape enabling the rower to sit in a bow side or stroke side position. As shown, each of the rowing positions includes a series of slotted tracks. The first series of slotted tracks includes three tracks 21, 21 22.
These are used for attachment of the footplate. A second set of tracks 21′, 22′ are provided perpendicular to the first set of runners for mounting the footplate when the rowers are in the alternative position. The footplate may easily be disengaged from one set of tracks and connected to the perpendicular set of tracks. Additional tracks 27, shown best in FIG. 9 are provided for mounting a seat. Tracks 27′ are provided generally perpendicular to the tracks 27 for mounting the seat in an alternative position dependent on whether the rower is rowing bow side or stroke side. The removal and replacement of seats and footplates are well known in rowing craft.
In a preferred example, the outer tracks 21 are separated by a distance of around 280 mm, as are the seat tracks 27.
In the example shown in FIG. 5, where the craft is to be used with the rowers rowing bow side, the rowers in the positions shown in the upper left and lower right of the drawing will have their feet fixed in the top and bottom portions of the cross-shaped recesses respectively, whilst the rowers in the bottom left and upper right positions shown in the diagram will have their feet fixed in the right side and left side portions of the rcesses as shown in the Figure. This arrangement is best shown in FIG. 9. When the rowers are rowing stroke side, the rowers in the positions in the upper left and lower right portions will have their feet fixed in the left- and right-hand portions of the recesses respectively, and the rowers in the bottom left and upper right positions will have their feet fixed in the top and bottom portionsof the recesses respectively as shown in the Figure. In the example shown in FIG. 5, the overall diameter of the craft should be around 3 m. In this case, the footwells are preferably between around 60 cm and 110 cm to 115 cm from the centre point of the craft. The depth from the outer rim of the craft to the bottom of the footwell is advantageously around 35 cm, most preferably 34 cm, with the depth of the footwell below the height of the seat being around 17 cm. Of course, different sizes are possible, and will especially depend upon the number of rowers.
As shown in FIG. 6, the craft of the present embodiment includes a generally central recess 25. When the craft is placed on the surface of the water, air will be trapped within this recess enhancing the buoyancy of the craft. The increase in buoyancy will be dependent on the volume of air trapped within the recess 25. To adjust the volume of air trapped within the recess, and accordingly the buoyancy of the craft, an opening with a suitable closure 26 is provided in the wall of the buoyancy recess. The closing means 26 may be in the form of a bung, or could be in the form of a screw cap closure or other similar closure means. In use, the closure 26 can be opened to allow air from within the buoyancy recess 25 to escape to the atmosphere when the craft is placed on the surface of the water, and then closed when the desired buoyancy has been achieved. Additionally, air may be added to the recess, for example by use of a 12 v or similar compressor, to increase bouyancy. This arrangement is particularly advantageous as it allows the craft to be used with crews having different weights whilst the craft remains at an optimum level in the water, or allows adjustment of the level for training purposes, and to determine the optimum height of the craft.
As shown in FIGS. 7 a and 7 b, the craft may be formed from two separate parts. The parts may be formed or moulded from glass reinforced plastic. The mouldings may be formed by polyethylene or other suitable plastics material. In the two-part version, the outer hull is formed as one part, and an inner part is formed including the surfaces on which the rowers sit, and the footwells. By attaching the two parts, for example by adhesive, bolts or other suitable attaching means, the overall rigidity and strength of the craft can be enhanced. In a preferred example, the two parts of the craft are attached around the outer circumference which defines the riggers, in the central portion and in the footwells. As shown best in FIG. 8, the outer circumference is suitably shaped for receiving the gate into which the oars are provided and held during the rowing stroke.
In an alternative example, the platform may be formed in a single piece with a hollow structure. This replaces the two piece moulding described above. In this case, the one piece hollow platform can be formed by a rotational mulding technique. Such a manufacturing technique is simpler and less expensive than the two piece moulding technique described above.
It is believed that where the craft is of a size suitable for only four rowers, the circumferential forces created during use of the craft will not be excessive, and accordingly that no radial restraints will be required.
In use, the craft of the present invention, in either aspect, can be used within a restricted volume of water, for example in a swimming pool or small lake.
Rowers can occupy the positions within the craft, and, as described above, will all sit in the same direction. When the rowers row the craft, the craft will rotate generally about the central axis. Accordingly, the craft will be propelled around the central axis, but will generally not deviate from its position. It is this that enables the craft to be used in a restricted area. Further, a trainer can watch the training without needing to move from a fixed position.

Claims

1. A water craft comprising a support arranged to float on water and having a central axis arranged to lie generally perpendicular to the surface of the water when the support is floating on the water, and including a number of rowing positions arranged around the axis at or near the periphery of the support, such that rowers in the rowing positions propel the craft around the central axis.

2. The water craft of claim 1, in which the support is in the form of a ring for supporting the rowing positions.

3. The water craft of claim 2, in which radial retaining arms are provided to connect the ring to a central ring

4. The water craft of claim 3, in which the radial retaining arms are rigid.

5. The water craft of claim 3, in which the radial retaining arms are formed from a flexible material.

6. The water craft of claim 5, in which the radial retaining arms are selected from the group consisting of ropes and wires.

7. The water craft of claim 2, in which the ring is toroidal in shape.

8. The water craft of claim 1, in which the support is in the form of a platform.

9. The water craft of claim 8, in which the platform has a generally circular shape.

10. The water craft of claim 8, in which the platform is formed in a number of parts including a lower part arranged to float on the water, and an upper part on which the rowing positions are located.

11. The water craft of claim 10, in which the parts are formed using a composite material.

12. The water craft of claim 11, in which the composite material is glass reinforced polyester.

13. The water craft of claim 1, in which the support includes at least one hollow portion for increasing the buoyancy of the craft.

14. The water craft of claim 1, in which the buoyancy of the craft is adjustable.

15. The water craft of claim 14, in which the buoyancy of the craft is adjusted by providing a void on the underside of the craft to trap air under the craft, and including an opening through which the volume of air in the void may be adjusted.

16. The water craft of claim 15, in which the opening may be selectively opened, and is formed from one of the group consisting of a bung, a cap and a valve.

17. The water craft of claim 15, in which the buoyancy may be increased by adding air or other gas to the void.

18. The water craft of claim 17, in which air or other gas is added to the void using a compressor.

19. The water craft of claim 18, in which air or other gas is added to the void using a battery powered compressor,

20. The water craft of claim 17, in which air or other gas is added to the void using a source of compressed gas.

21. The water craft of claim 1, the craft being formed from polyethylene.

22. The water craft of claim 1, including a desired number of rowing positions.

23. The water craft of claim 22, including four rowing positions.

24. The water craft of claim 1, in which the rowers' positions are adjustable to allow each of the rowers to reverse their position.

25. The water craft of claim 1, in which radial restraints are provided between the centre of the craft and each of the rowers to prevent the rowers being forced outwardly due to circumferential forces during use.

26. The water craft of claim 1, in which the craft has an overall diameter of around 3 m.

27. The water craft of claim 1, in which the support is formed as a single hollow component by rotational moulding.

28. A method of training for a paddle propelled event such as canoeing, rowing or dragon boating comprising floating a water craft including a support on the surface of a body of water, the support having a central axis arranged to lie generally perpendicular to the surface of the water, the support including a number of rowing positions arranged around the axis at or near the periphery of the support, providing rowers in some or all of the rowing positions, each of the rowers having an oar, the rowers rowing with the oars to propel the craft around the central axis.