A personal watercraft

Abstract

A personal watercraft 1 comprises an elongate float body 2 configured to provide sufficient floatation to support a user when the watercraft is deployed in / on a body of water; a pair of hand-operated

Description

Personal watercraft that allow a user to move across the surface of a body of water using a walking or skiing type movement are known. US1,1034,422, US9,365,272, and US9,051,038 show and describe stand up paddleboard type craft with a paddlewheel driven by pedals, a ‘walker’ arrangement, or similar. AU2013228031 shows and describes a watercraft where a standing user uses a lever to drive a paddlewheel, in a single-hull personal watercraft. US1,589,708 shows and describes a mechanism where the user manipulates a lever to drive a paddlewheel. The mechanism is intended to be fitted to different types of watercraft (Tow boat, canoe, or similar types of watercraft’), with the paddle wheels positioned each side of the hull. In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art. SUMMARY It is an object of the present invention to provide a personal watercraft which goes some way to overcoming the abovementioned disadvantages or which at least provides the public or industry with a useful choice. The term “comprising” as used in this specification and indicative independent claims means “consisting at least in part of”. When interpreting each statement in this specification and indicative independent claims that includes the term “comprising”, features other than that or those prefaced by the term may also be present. Related terms such as “comprise” and “comprises” are to be interpreted in the same manner. 07 03 25 As used herein the term "and / or" means "and" or "or", or both. As used herein "(s)" following a noun means the plural and / or singular forms of the noun. Accordingly, in a first aspect the present invention may broadly be said to consist in a personal watercraft, comprising: an elongate float body, configured to provide sufficient floatation to support a user when the watercraft is deployed in / on a body of water; a pair of hand-operated levers, connected to the elongate float body and configured to be manipulated by a user standing on the float body; a paddle wheel or wheels connected to the float body and configured to operate to propel the watercraft 10 through the water, and; a connection mechanism configured to connect between the levers and paddle wheel(s) so that backwards and forwards motion of the levers when manipulated by a user causes propulsive rotation of the paddle wheel(s); wherein the connection mechanism comprises gear wheels and a drive shaft; and wherein the gear wheels comprise a pair of conical gear wheels connected one each to each of the levers, the conical gearwheels configured so that backwards and forwards motion of the levers causes rotation of the conical gearwheels about an axis of rotation substantially perpendicular to the front-rear axis of the float body, the connection mechanism further comprising a shaft connected to the conical gearwheels and aligned substantially in parallel with the elongate axis of the float body, the shaft and conical gear wheels connected so that rotation of the gear wheels causes rotation of the shaft. In an embodiment, the connection mechanism further comprises pawls associated with each of the conical gear wheels, the pawls mounted so as to releasably engage one each with the conical gear wheels, such that when a user pushes a lever, the pawl on that side engages with the conical gearwheel causing the gear to turn, the mechanism configured so that the opposite conical gear remains passive during this action. In an embodiment, the mechanism further comprises lever gearwheels located one each at the lower ends of the levers and directly connected to the levers so that operation of the levers causes the lever gear wheels to rotate. In an embodiment, each of the lever gear wheels has a diameter of substantially 125mm and 60 teeth. In an embodiment, the personal watercraft further comprises a reducer gear associated with each lever gear wheels, the reducer gear of smaller diameter than the lever gearwheel. In an embodiment, the reducer gears each have a radius of substantially 45mm and 20 teeth. In an embodiment, the personal watercraft further comprises a conical transmission gear located so as to engage with the conical lever gears, the conical transmission gear connected to the shaft so that rotation of the conical transmission gear causes rotation of the shaft. In an embodiment, the paddle wheels comprise a pair of wheels mounted one each on each side of the elongate float body. In an embodiment, the paddle wheels are mounted at or towards the front of the elongate float body. In an embodiment, each of the paddle wheels comprises 10 blades spaced at substantially equal circumferential intervals. In an embodiment, the personal watercraft further comprises a pair of outriggers mounted at the outer ends of the paddlewheels. In an embodiment, the personal watercraft further comprises at least one handbrake configured to hold the paddlewheel or wheels in position when activated. In an embodiment, the at least one handbrake is mounted on at least one of the levers. With respect to the above description then, it is to be realised that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth. Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. BRIEF DESCRIPTION OF THE FIGURES Further aspects of the invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings which show an embodiment of the device by way of example, and in which: Figure 1 shows a perspective view from the front and to one side of a personal watercraft according to an embodiment of the invention, the watercraft comprising a main central body, a pair of outriggers each side of and spaced from the main body at the front of the main body, a pair of paddlewheels on each side of the main body between the outrigger and the main body, and a pair of user-operated levers extending upwards from the main body, the levers connected to the paddle wheels via a mechanism that converts the backwards-and-forwards push-pull motion of the levers into rotational movement of the paddle wheels. Figure 2 shows a schematic close-up top view of the conversion mechanism of figure 1. DETAILED DESCRIPTION Embodiments of the invention, and variations thereof, will now be described in detail with reference to the figures. An embodiment of personal watercraft is shown in figure 1. One side of the watercraft is shown in detail, with the watercraft 1 symmetrical about a central axis running front-to-rear. The right-hand side of the watercraft 1 is shown in detail (right hand from the point of view of a user standing on the watercraft 1). All the elements described below are for the right-hand side, and have direct equivalents on the lefthand side, so when items are described as ‘a pair’ or similar, then it should be understood that there are two identical elements, one on each side, although only the right-hand element is shown in detail. The watercraft 1 in the preferred embodiment comprises: a central main body 2; a pair of outriggers 3; a pair of paddlewheels 4; a pair of user-operated levers 5 extending upwards from the main body 1, and; a mechanism 6 that connects between the levers 5 and the paddlewheels 4 to convert the backwards-and-forwards push-pull motion of the levers 5 into rotational movement of the paddle wheels 4. The main body 2 in the preferred embodiment is substantially around two metres long, with an upper surface configured to allow a user to stand thereon. The main body 2 is elongate and thin, the overall shape forming a streamlined central hull for the watercraft 1. The outriggers 3 are located each side of the main body 2, and are spaced away from the main body 2 at the front of the main body at a distance of around one metre between the outer side of the main body 2 and the inner side of the outrigger 3. Each of the outriggers 3 is formed as an elongate streamlined hull, aligned substantially in parallel to the hull of the main body 2. The outriggers 3 are connected to the main body 2 by connector struts 7, that extend between the outer side of the main body 2 and the inner side of the outrigger 3. In the preferred embodiment, two struts are used, one towards each end of the outrigger, aligned perpendicular to front-rear axis of the hulls of the outriggers 3 and the main body 2. The paddlewheels 4 are located one each in the spaces between the outriggers 3 and the main body 2. Each of the paddlewheels 4 is mounted on a single elongate member 8 or shaft 8 that passes through the centre of the paddlewheel (along the axis of rotation of the paddlewheel). The elongate member 8 extends between the main body 2 and the outrigger 3, and supports the paddlewheels 4 and keeps these connected in position as part of the watercraft 1. The elongate member 8 forms an axis of rotation for the paddlewheel 4, and is aligned so that the axis of rotation is in use substantially horizontal and extends perpendicular to the front-rear axis of the hulls of the outriggers 3 and the main body 2. The elongate member 8 passes across the top of the outriggers 3 and main body 2, and is connected to the top surface of these by bearing clamps 10. In the preferred embodiment, shaft 8 is a 20mm diameter aluminium rod or tube. The paddlewheel 4 is mounted on the shaft 8 via support mounts 20. Each of the support mounts 20 comprises a 50mm diameter aluminium tube. Bearings (not shown) are located inside the support mounts 20, between the shaft 8 and the support mounts 20, to allow transfer of the power generated by the user from the rotating shaft 8 to the paddlewheel 4, and to allow the paddlewheel 4 to turn freely, when needed. Each of the paddlewheels comprises ten blades, positioned at equal angular intervals around the axis of rotation. The axis of rotation is at a height above the waterline so that a blade substantially directly underneath the axis member 8 will be only just fully submerged (that is, with it’s top edge just under the surface of the water). The main body is configured so that a user can stand on the top surface of the main body 2 at a point substantially halfway along the main body 2. The user-operated levers 5 are connected one on each side of the main body 2, slightly towards to the front of the main body 2 from the mid-point, so that when a user is standing on the main body, substantially halfway along the main body 2, the user will be able to grasp the levers 5 and push and pull these forwards and rearwards, pivoting them around their connection point with the main body 2, to an angle of between ten and fifteen degrees from the vertical in each direction. As noted above, the mechanism 6 connects between the levers 5 and the paddlewheels 4 to convert the backwards-and-forwards push-pull motion of the levers 5 into rotational movement of the paddle wheels 4. The mechanism 6 is located inside the main body 2, running between the levers 5 and the rotational axis of the elongate members 8. The mechanism 6 of the preferred embodiment comprises gearwheels 9 which are located at each side of the main body, one each at each of the lower ends of the levers 5 respectively. The gear wheels 9 have an axis of rotation that extends substantially horizontally, substantially perpendicularly from the side of the main body 2. The gear wheels 9 have a diameter of 125mm, and each has 60 number of teeth, in the preferred embodiment. A reducer gear 11 is mounted above each of the gear wheels 9. The reducer gears 11 in the preferred embodiment have a radius of 45mm and each has 20teeth. An aluminium tube 12 forms a mount and axis of rotation for the reducer gears 4. The tube 12 extends through the interior of the main body 2 and out of each side of the main body 2. A pair of conical lever gears 13a, 13b are mounted one each on each side of the interior of the main body 2. The lever gears 13a, 13b are mounted on the tube 12 so that the tube 12 forms an axis of rotation for the conical gears 13a, 13b. A pair of counter-positioned pawls 14a, 14b are mounted so as to engage one each with the lever gears 13a, 13b. When a user pushes a lever 5, the pawl 14 on that side will engage with the lever gear 13 (pawl 14a with gear 13a, pawl 14b with gear 13b), causing the gear 13 to turn. The gear on the other side is passive during this action (i.e. gear 13b is passive when gear 13a is engaged, and gear 13a is passive when gear 13b is engaged). A transmission gear 15, which also has the form of a conical gear, is located so as to engage with the lever gears 13a, 13b, with an axis of rotation aligned perpendicular to the axis of rotation of the lever gears 13a, 13b and running front-to-rear along the main body 2, from the gears 13 towards the front of the main body 2. As shown on figure 2, when a user pushes a lever 5 on the left-hand side, gear 13a will rotate clockwise (looking from the left-hand side of the figure). This causes transmission gear 15 to rotate clockwise (viewed from the front, or lower end of figure 2). When a user pushes the lever 5 on the opposite / right-hand side, this causes gear 13b to rotate anti-clockwise (viewed from the left-hand side of figure 2), which also causes transmission gear 15 to rotate clockwise (viewed from the front, or lower end of figure 2). When a user pulls the lever 5 on the left-hand side back, pawl 14b engages with gear 13b, which causes rotation of the gear 13b, and subsequently rotation of the transmission gear 15 clockwise (viewed from the front, or lower end of figure 2). As outlined above, both pushing and pulling turn the transmission gear 15 clockwise. A shaft 16 extends from transmission gear 15 towards the front of the main body 2. A conical paddle gear is connected to the front end of the shaft 16, which engages with a gear arrangement on the elongate member 10 as shown in figure 3, so that rotation of the shaft 16 causes rotation of the paddle wheels 4. The gear arrangement comprises a conical shaft gear 19a connected to the front end of the shaft 16 and rotating with the shaft 16. Shaft 16 and shaft gear 19a have coincident axes of rotation. The conical shaft gear 19a connects with and drives a conical paddlewheel gear 19b around an axis of rotation perpendicular to the axis of rotation of the conical shaft gear 19a, in the same plane (substantially in use, the horizontal plane). Paddlewheel gear 19b connects with the inner end of elongate member 8, which forms a rotational shaft for the paddlewheel 4 In an alternative form, the mechanism comprises one-way clutch bearings which are co-located with and / or form part of the bearing clamps 10. When a user pulls on the lever, the clutch is engaged and this causes the paddle wheel 4 to turn. However, there is no engagement and no resistance when a user pushes the lever in the opposite direction, due to the one-way clutch bearings. A handbrake 17 is connected at the top end of each lever 5. The handbrake 17 is connected to the paddlewheel on the same side of the main body 2. The handbrake comprises a lever or similar that can be grasped and squeezed by a user to activate the handbrake. The handbrake is connected to the paddlewheel 4 via a cable 18, 5 similar to the brake cable used on a bicycle. When the handbrake 17 is activated, it immobilises / stops the rotation of the paddle wheel on that side of the watercraft 1. This allows the watercraft 1 to be steered in a similar manner to a tank or other tracked vehicle, where movement is continued on one side while the other is stopped, causing rotation of the vehicle about a vertical axis. 10 In the preferred embodiment, all the gears described above (gears 13, 15, 19a / 19b) have a diameter of 60mm, with 30 teeth.

Claims

07 03 251. A personal watercraft, comprising:an elongate float body, configured to provide sufficient floatation to support a user when the watercraft is deployed in / on a body of water;a pair of hand-operated levers, connected to the elongate float body and configured to be manipulated by a user standing on the float body;a paddle wheel or wheels connected to the float body and configured to operate to propel the watercraft through the water;a connection mechanism configured to connect between the levers and paddle wheel(s) so that backwards and forwards motion of the levers when manipulated by a user causes propulsive rotation of the paddle wheel(s),wherein the connection mechanism comprises gear wheels and a drive shaft, andwherein the gear wheels comprise a pair of conical gear wheels connected one each to each of the levers, the conical gear wheels configured so that backwards and forwards motion of the levers causes rotation of the conical gear wheels about an axis of rotation substantially perpendicular to the front-rear axis of the float body, the connection mechanism further comprising a shaft connected to the conical gear wheels and aligned substantially in parallel with the elongate axis of the float body, the shaft and conical gear wheels connected so that rotation of the gear wheels causes rotation of the shaft.

2. A personal watercraft as claimed in claim 1 wherein the connection mechanism further comprises pawls associated with each of the conical gearwheels, the pawls mounted so as to releasably engage one each with the conical gear wheels, such that when a user pushes a lever, the pawl on that side engages with the conical gearwheel causing the gear to turn, the mechanism configured so that the opposite conical gear remains passive during this action.

3. A personal watercraft as claimed in claim 1 or claim 2 wherein the mechanism further comprises lever gearwheels located one each at the lower ends of the levers and directly connected to the levers so that operation of the levers causes the lever gear wheels to rotate.

4. A personal watercraft as claimed in claim 3 wherein each of the lever gear wheels has a diameter of substantially 125mm and 60 teeth.07 03 255. A personal watercraft as claimed in claim 3 or claim 4 further comprising a reducer gear associated with each lever gear wheels, the reducer gear of smaller diameter than the lever gearwheel.

6. A personal watercraft as claimed in claim 5 wherein the reducer gears each have a radius of substantially 45mm and 20 teeth.

7. A personal watercraft as claimed in any one of claims 1 to 5 further comprising a conical transmission gear located so as to engage with the conical lever gears, the conical transmission gear connected to the shaft so that rotation of the conical transmission gear causes rotation of the shaft.

8. A personal watercraft as claimed in any one of claims 1 to 7 wherein the paddle wheels comprise a pair of wheels mounted one each on each side of the elongate float body.

9. A personal watercraft as claimed in claim 8 wherein the paddle wheels are mounted at or towards the front of the elongate float body.

10. A personal watercraft as claimed in claim 8 or claim 9 wherein each of the paddle wheels comprises 10 blades spaced at substantially equal circumferential intervals.

11. A personal watercraft as claimed in any one of claims 8 to 10 further comprising a pair of outriggers mounted at the outer ends of the paddlewheels.

12. A personal watercraft as claimed in any one of claims 1 to 11 further comprising at least one handbrake configured to hold the paddlewheel or wheels in position when activated.

13. A personal watercraft as claimed in claim 12 wherein the at least one handbrake is mounted on at least one of the levers.

Images