GB2421191A

GB2421191A - Roller skate or skateboard propulsion

Info

Publication number: GB2421191A
Application number: GB0427485A
Authority: GB
Inventors: Leslie Thomas Bater
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-12-15
Filing date: 2004-12-15
Publication date: 2006-06-21
Also published as: GB0427485D0

Abstract

A roller skate or skateboard comprises ground engaging wheels 16 that are driven by a user through a mechanism 18,20,24,40. The mechanism may comprises an arm 18 pivotally connected between a platform and the rear axle 36, a wedge shaped member 20 with gear teeth 24 and a pinion gear 40 mounted on the axle 38 to engage with the teeth 24 of the wedge shaped member. In use, propulsion of the roller skate 10 is achieved by movement of the rear of the platform 12 downwardly so that it pivots about member 32 causing gear teeth 24 to drive the pinion 40 and thus the wheels 16. When the user raises his/her foot from the rear of the platform the pivoting arrangement 28 and a free wheel arrangement between the pinion 40 and the axle 38 allows the wedge shaped member 20 to return to the starting position, as shown in figure 1, ready for the wheels 16 to be driven again. Alternative arrangements for the drive mechanism are given in figures 2-6. Also disclosed is a propulsion mechanism for a trolley (see figure 5).

Description

Wheeled Device The present invention relates to a wheeled device and is particularly but not exclusively concerned with a roller skate, skateboard or trolley. A known roller skate comprises a frame holding a plurality of free-turning wheels or rollers. The frame is fitted to the base of a shoe allowing the shoe to roll over a hard surface. The frame is either integral with the sole of a specially adapted shoe, or is secured by straps to a normal shoe. In this way, a person wearing a roller skate on each foot may roll over a hard surface. Momentum in a desired direction is generated by the user performing an exaggerated running or walking like action where each roller skate is alternately passed by the other at an angle to the intended direction of travel. This method of using known roller skates requires a user to time his movements accurately to generate momentum in the intended direction of travel.Furthermore, any potential energy stored in lifting and passing the skates alternately in front of each other is not used efficiently to further propel the user, or indeed at all. A known skateboard comprises an elongate board mounted on front and rear two-wheeled trucks. In use, a person may stand with both feet on the board and free wheel across a hard surface. A person may propel the skateboard by lifting one foot from the board and pushing it against the hard surface. In this way the user must time his movements accurately and must remove one foot from the board, thereby having to constantly shift both balance and weight, to generate forward momentum. According to a first aspect of the invention there is provided a roller skate or skateboard comprising a ground engaging wheel that is driven around by a user through a mechanism. In this way, a user is able to generate forward momentum by his own effort through the mechanism and without, in the case of a roller skate, having to perform an exaggerated walking or running like action, or in the case of a skateboard having to use a foot against the ground to generate forward momentum. Preferably the mechanism provides a mechanical advantage. The user of the roller skate or skateboard of the invention thus will be able to travel faster. Preferably the mechanism is operated by a user moving their feet, preferably, moving their feet downwardly. The mechanism may be returned to its original position on lifting of the user's foot either by the action of gravity or by a resilient biasing means, such as a spring. Preferably, the roller skate or skateboard comprises a surface to support a load, namely a person, the surface being connected to the said driven wheel so that the surface may move relative to the wheel, this relative movement resulting in driving of the wheel by the mechanism. Preferably, there is a pivoting connection between the surface and the driven wheel. This enables relative movement of the surface and the driven wheel by pivoting or rocking the surface by a user. In this way, the relative pivotal movement of the surface to the wheel can be used to drive the mechanism and to generate forward momentum. According to a further aspect of the invention there is provided a wheeled device comprising a ground engaging wheel that is driven around by a user through a mechanism, the device including a surface to support a load, the surface being connected for pivoting movement with respect to the driven wheel, the pivoting connection enabling relative movement of the surface and the driven wheel so that the surface and the load thereon can be rocked back and forth by a user, the rocking motion operating the mechanism to drive the wheel. In this way, a user may generate forward momentum of the wheeled device by rocking the load carried thereon. A user is therefore able to generate forward momentum of the wheeled device without, where the wheeled device is a roller skate, having to perform a walking or running like action, or where the wheeled device is a skateboard, having to use a foot against the ground to generate forward momentum, or where the wheeled device is a trolley, pushing the trolley. Furthermore, a roller skater or skateboarder will be able to travel faster and loads carried on a trolley will be easier to move. Preferably the mechanism incorporates a free wheel. Thus rolling can occur when wheel not driven. The mechanism may be any suitable kind of mechanism, such as a pulley mechanism or a spring mechanism, but preferably the mechanism comprises a gear mechanism. Preferably, the driven wheel has a gear wheel or pinion, where conveniently the gear wheel or pinion may be coaxial with the axis of the driven wheel. Preferably then the surface carries a gear member, where preferably the gear member is arranged to engage the gear wheel to drive the wheel around. The gear member may be a toothed rack. The toothed rack may be pivotally attached to the surface, in which case the toothed rack is preferably resiliently biased against the gear wheel or pinion, or may be fixedly attached to the surface in which case the teeth may lie on a notional circle. Preferably, a member connects between the surface and the driven wheel, and preferably the member is pivotally connected to the surface. The member may be a swing arm. The member may define a longitudinal slot for receiving an axle of the driven wheel, and preferably the axle of the driven wheel is held within the slot. In this way the driven and gearwheel or pinion may move, for example, rearwardly along the slot. The device, skate or skateboard may have one or a plurality of driven wheels. The device, skate or skateboard may also have at least one rolling ground engaging wheel. The or each driven wheel may be of the same size as the or each rolling wheel or may be larger. The wheeled device may be a trolley having front and rear pairs of wheels, each pair of wheels being driven by the user through a mechanism acting upon an axle between the pair of wheels. A skate may have one or two front rolling ground engaging wheels and one or two rear driven ground engaging wheels. According to a further aspect of the invention there is provided a method of propelling a roller skate or skateboard, the roller skate or skateboard having a ground engaging wheel, the axis of the driven wheel being movable relative to the user's foot in the skate or on the board, the method comprising the user pushing his foot down in the skate or on the board, the resulting relative movement between the foot and the wheel being transferred through a mechanism to drive the wheel around. Embodiments of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a wheeled device in accordance with a first embodiment of the invention; Figure 2a is a side view of a wheeled device in accordance with a second embodiment of the invention; Figure 2b is a plan view of a wheeled device of Figure 2a; Figure 3 is a side view of a wheeled device in accordance with a third embodiment of the invention having the near side wheels removed; Figure 4 is a side view of a wheeled device in accordance with a fourth embodiment of the invention having the near side wheels removed; and Figure 5 is a side view of a wheeled device in accordance with a fifth embodiment of the invention. Figure 6 is a side view of a skate board in a sixth embodiment of the invention. Referring to Figure 1, the wheeled device 10 of the first embodiment is a roller skate. The device 10 comprises an elongate planer platform 12, a pair of front wheels 14 located at one end of the platform 12, and a pair of rear wheels 16 located at the other end of the platform 12. The platform 12 is shaped like the sole of a shoe in plan but is substantially flat and of uniform thickness. The platform 12 may be made of wood. Straps (not shown) are provided to attach a user's shoe to the platform 12 in known fashion. The front wheels 14 are connected together by an axle 22. The axle 22 is attached to the underside of the platform 12 at the front. The front wheels 14 can rotate freely. The axle 22 spans the platform 12 and the wheels 14 straddle the platform 12. The wheels 14 and axle 22 may be of standard type. A wedge-shaped member 20 fixed to the underside of the platform 12. The wedge shaped member 20 is in the form of a flat plate. The plane of the member 20 is perpendicular to the plane of the platform 12. A long edge 26 of the member 20 is securely fixed to the platform 12 along the longitudinal axis of the platform 12, such that the wedge shaped member 20 points toward the axle 22 of the front wheels 14 and the rear edge 25 faces the rear wheels 16. The wedge-shaped member 20 has gear teeth 24 running along the rear edge 25 of the wedge. The rear edge 25 of the wedge-shaped member 20 lies on a notional circle. A pivoting arrangement 28 is provided at the point 29 of the wedge-shaped member 20. The pivoting arrangement 28 comprises a circular aperture 30 within which is received a cylindrical member 32. At each end of the cylindrical member 32 is attached a pivoting arm 18. Each pivoting arm 18 extends perpendicularly away from the cylindrical member 32 and defines an aperture 36 at its opposite end. The aperture 36 receives the rear axle 38 which connects the pair of rear wheels 16. A pinion 40 is provided at the mid-point of the rear axle 38 to engage the gear teeth 24 of the wedge-shaped member 20. The pinion 40 is attached to the axle 38 via a free wheel (not shown). In use, propulsion of the wheeled device 10 is achieved by movement of the rear of the platform 12 downwards toward the rear wheels 16 and axle 38 pivoting about the cylindrical member 32. Propulsion is achieved because the gear teeth 24 of the wedge-shaped member 20 engage the gear teeth of the pinion 40 to drive the pinion 40 around. The pinion 40 drives the axle 38 which drives the wheels 16 around so that the skate is propelled forwards. The swing arm 38 and pivoting arrangement 28 enables the platform 12, wedge-shaped member 20 and gear teeth 24 to move against the pinion 40. The free wheel (not shown) between the pinion 40 and rear axle 38 allows the rear axle 38 to continue to rotate when the gear teeth 24 on the wedge shaped member 20 have travelled down as far as they will go.When the user raises his foot, the pivoting arrangement 28 allows the wheels 16 to drop under their own weight so that the skate is back in the starting position for the wheels to be driven again. The wedge-shaped member 20 with its gear teeth 24, the pinion 40 and the arms 18 constitute the aforesaid "mechanism". In this way, a person wearing the skates can propel themselves by lifting their heel and then letting their weight operate the mechanism to drive themselves along. In this embodiment the platform 12 is made of wood, but it is understood that the platform may be made of any suitable material. The exact shape or material of construction of the platform 12 is not essential to the invention, and it may change depending on the user. However, it is important that the platform 12 is suitable for a foot or shoe to rest on it and holding the wheeled device 10 thereto. Figures 2a and 2b show the second embodiment. The second embodiment is similar to the first and only the differences from the first embodiment will be described. The wheeled device 110 of the second embodiment comprises an adapted platform 112 having a slot 142 extending from the rear edge of the platform 112. The wheeled device 110 comprises a single large rear wheel 116. Part of the wheel 116 passes through the slot 142 of the platform 112. The rear wheel 116 has a coaxial pair of pinions 140 one on each side thereof. Each pinion 140 is connected to an axle 138 by a free wheel (not shown). The axle 138 joins the rear wheel 116 and pinions 140 to pivoting arms 118. Two wedge-shaped members 120 attached to the platform 112 engage the pinions 140. The single rear wheel 116 is much larger than the front wheels 114. As the gearing between the wedge teeth 124 and the pinions 140 is similar to the first embodiment, this means that the skate of the second embodiment will have a higher gearing at the ground and consequently will have a higher top speed. The larger size also enables it to ride over bumps and obstructions better and also assists the wheel 116 in building up and maintaining momentum. Placing the large rear wheel 116 behind the user's foot enables the foot to remain reasonably low to the ground. As the rear wheel 116 is central in this embodiment, the use of two wedge-shaped members 120 and two pinions 140 means that the design is still symmetrical and balanced. Figure 3 shows the third embodiment of the invention. The third embodiment is similar to the first and only the differences from the first embodiment will be described. The wheeled device 210 of the third embodiment includes an elongate longitudinal member 244 connected to the axles mounting the front wheels 214 and rear wheels 216. The front of the platform 212 is pivotally attached to the front of the member 244. The platform 212 is pivotally connected at the back to an elongate toothed rack 220. The toothed rack 220 extends forwards from the rear of the platform 212 at an acute angle. The toothed rack 220 meshes with the pinion 240 and is urged theretoward by a spring mechanism (not shown) to ensure the toothed rack 220 and pinion 240 are in engagement. In use, when a user pushes down on to the platform 212 the toothed rack 220 moves over the pinion 240 thereby rotating the pinion 240 and causing the rear wheels 216 to rotate. As the toothed rack 220 moves over the pinion in this way, the rack 220 is pivoted back towards the platform 212 and finally tends toward the horizontal. The end of the downward travel of the platform 212 is reached when the platform 212 becomes substantially horizontal and the toothed rack 220 folds back into the platform 212 like a jackknife. In this way, the wheeled device 210 is driven forward. In this embodiment, the lower end of the toothed rack 220 does not travel downwards towards the surface over which the wheeled device 210 is travelling, unlike the wedge-shaped members of the first and second embodiments, where it might hit an obstruction on the ground.To continue his progress, the platform 212 is then raised by the user and the toothed rack 220 opens therefrom under its own weight and the bias of the spring mechanism (not shown). As it descends, the toothed rack 220 is in contact with the pinion 240 causing it to rotate in the opposite direction. The freewheel (not shown) ensures that this rotational movement is not transferred onto the axle 238 and rear wheels 216. The fourth embodiment of the invention is shown in Figure 4. The difference between this embodiment and the third embodiment is that the axle 322 joining the rear wheels 316 is held by a bush (not shown) held within a slot 346 in member 344. The rack 320 is fixedly attached to the platform 312 so that the rack 320 and platform 312 do not move relative to each other. In use, when the platform 312 moves towards the member 344 the rack 320 engages the pinion 340 causing the wheels 316 to rotate. The wheels 316, axle 322 and pinion 340 are pushed back along the slot 366. The forward rotation of the rear wheels 316 pushes the pinion 340 against the rack 320 and the wheeled device 310 is pushed forward. The fifth embodiment of the invention is shown in Figure 5. A trolley 410 comprises a platform 412 pivotally attached to a member 413 having connected thereto front wheels 414 and rear wheels 416. The platform 412 comprises a flat portion 418 and raised handle 420. The platform 412 is pivotally connected to the member 413 via a pivot 422 at a point midway between the front wheels 414 and rear wheels 416. The front wheels 414 and rear wheels 416 are connected to the member 413 by axles 424. A pinion 416 is connected via a free wheel (not shown) to each axle 424 and is placed to mesh with a wedge-shaped member 428 having gear teeth 420 along its rear curved edge 425. In use, when a user pushes and pulls the handle 420 of the trolley 410, the platform 412 is rocked. When the platform 412 tips forward on the pivot 422, the front wedge-shaped member 428 moves over the pinion 426 causing the pinion 426 and the front wheels 414 to rotate. This action propels the trolley 410. At the same time, the rear wedge-shaped member 428 causes the rear pinion 426 to rotate in the direction counter to the front pinion 426. However, the free wheel mechanism (not shown) prevents the rear pinion 426 from causing the rear wheels 416 from rotating in the opposite direction to the front wheels 414. When the trolley platform 412 is tipped backwards the rear wheels 416 are driven and the front wheels 414 freewheel and the trolley 410 is propelled further in the same direction. Using the trolley of the invention, a heavy load can be placed on the platform 412 and, rather than the user having to overcome the inertia of the heavy load to push it forwards, as with a conventional trolley, he can merely rock the heavy load through a small angle about its point of balance, and in this way the trolley moves itself forward, with much less effort on the part of the user. The sixth embodiment of the invention is shown in Figure 6. The sixth embodiment is similar to the fifth embodiment and only the differences from the fifth embodiment will be described. The wheeled device of the fifth embodiment is a skate board 510. The construction of the device 510 of the fifth embodiment underneath the platform 512 is substantially the same as the construction of the trolley 410 of the fourth embodiment beneath the platform 412. The handle 420 is omitted and the platform 512 is lengthened and curved and at the ends in conventional fashion. The skate board 510 of the fifth embodiment is also slimmer than the trolley 410 of the fourth embodiment and is generally of substantially the same dimensions in plan as a standard skate board. In use, the user places their feet on the platform 512 in the usual fashion. The user can then propel the skate board by rocking the platform up and down about the central pivot 522 so that the toothed, wedge shaped members 428 drive the pinions 426 to drive the wheels 514 and 516 to rotate. As in the trolley 410 of the fourth embodiment, the skate board 510 of the fifth embodiment drives the front and rear wheels alternately as the platform 512 is rocked up and down about the pivot 522. Thus, the user does not have to place one foot in the ground in order to increase speed, but will keep both feet on the skate board.In this way the user will be able to propel himself to higher speeds on level ground than a conventional skate board, given the appropriate gearing to the wheels, and can stand in a balanced position on the platform 512 at all times rather than having to take one leg of the platform 512 as in a conventional skate board. In alternative embodiments, the drive mechanisms of the second or third embodiments may be substituted for the drive mechanism of the first, fourth or fifth embodiments.

Claims

1. A wheeled device comprising a roller skate or skateboard comprising a ground engaging wheel that is driven around by a user through a mechanism.

2 A wheeled device according to claim 1, wherein the mechanism is operated by the user moving their foot or feet.

3. A wheeled device according to claim 2, wherein the mechanism is operated by the user moving their foot or feet downwardly.

4. A wheeled device according to claim 1, 2 or 3, wherein the roller skate or skateboard comprises a surface to support a load, such as a user's foot, the surface being connected to the said driven wheel so that the surface can move relative to the wheel, this relative movement resulting in driving of the wheel by the mechanism.

5. A wheeled device according to claim 4, wherein there is a pivoting connection between the surface and the driven wheel.

6. A wheeled device according to claim 5, wherein the pivoting connection enables relative movement of the surface and the wheel by pivoting or rocking of the surface by a user.

7. A wheeled device comprising a ground engaging wheel that is driven around by a user through a mechanism, the device including a surface to support a load, the surface being connected for pivoting movement with respect to the driven wheel, the pivoting connection enabling relative movement of the surface and the driven wheel so that the surface and the load thereon can be rocked back and forth by a user, the rocking motion operating the mechanism to drive the wheel.

8. A wheeled device according to any preceding claim, wherein the mechanism comprises a gear mechanism.

9. A wheeled device according to claim 8, wherein the driven wheel has a gear wheel or pinion.

10. A wheeled device according to claim 9, wherein the gear wheel or pinion is coaxial with the axis of the driven wheel.

11. A wheeled device according to claim 10 when dependent on claim 4 or claim 5, wherein the surface carries a gear member.

12. A wheeled device according to claim 11, wherein the gear member is arranged to engage the gear wheel or pinion to drive the driven wheel around.

13. A wheeled device according to claim 11 or claim 12, wherein the gear member is a toothed rack.

14. A wheeled device according to claim 13, wherein the toothed rack is pivotally attached to the surface.

15. A wheeled device according to claim 14, wherein the toothed rack is resiliently biased against the gear wheel or pinion.

16. A wheeled device according to claim 13, wherein the gear wheel or pinion is fixedly attached to the surface.

17. A wheeled device according to claim 16, wherein the teeth of the toothed rack lie on a notional circle.

18. A wheeled device according to any of claims 4 to 17, wherein a connecting member connects between the surface and the driven wheel.

19. A wheeled device according to claim 18, wherein the connecting member is pivotally connected to the surface.

20. A wheeled device according to claim 19, wherein the connecting member is a swing arm.

21. A wheeled device according to claim 18, 19, or 20, wherein the connecting member defines a longitudinal slot for receiving an axle of the driven wheel.

22. A wheeled device according to claim 21, wherein the axle of the driven wheel is held within the slot.

23. A wheeled device according to any of claims 4 to 22, wherein the wheeled device is a trolley.

24. A wheeled device according to any of claims 4 to 23, wherein the device has front and rear pairs of wheels, each pair of wheels being driven by the user through a mechanism acting upon an axle between the wheels of the pair.

25. A wheeled device according to any preceding claim, wherein the mechanism incorporates a free wheel.

26. A wheeled device according to any preceding claim, wherein the mechanism is returned to its original position after movement by a resilient biasing means.

27. A wheeled device as claimed in claim 26, wherein the resilient biasing means is a spring.

28. A wheeled device according to any preceding claim, wherein the mechanism provides a mechanical advantage.

29. A wheeled device according to any precedmg claim, wherein the device has at least one free rolling ground engaging wheel.

30. A wheeled device according to claim 29, wherein the or each driven wheel is larger than the or each rolling wheel.

31 A wheeled device according to any preceding claim, wherein the device has a plurality of driven wheels.

32. A wheeled device according to claim 29 or claim 30, wherein the device has one or two front rolling ground engaging wheels and one or two rear driven ground engaging wheels.

33. A wheeled device substantially as described herein with reference to Figs 1, 2a and 2b, 3, 4, 5 or 6 of the accompanying drawmgs.

34. A method of propelling a roller skate or skateboard, the roller skate or skateboard having a ground engaging wheel, the axis of the driven wheel being movable relative to the user's foot m the skate or on the board, the method comprising the user pushing his foot down in the skate or on the board, the resulting relative movement between the foot and the wheel being transferred through a mechanism to drive the wheel around.

35. A method of propelling a wheeled device, the method being substantially as described herein with reference to Figs. 1, 2a and 2b, 3, 4, 5 or 6 of the accompanying drawings.