The invention relates to a drive mechanism for a wheel, and in particular to a drive mechanism for a wheel on a vehicle such as a scooter or a roller skate.

Drive mechanisms are known in which a rack and pinion is used to translate linear movement generated by a foot pedal into rotational movement of a wheel. The invention relates to a new construction for such a drive mechanism.

The invention provides a drive mechanism for a wheel comprising an oscillatory foot pedal, a wheel having an axle connected to at least one pinion which is mounted on a rack, and a link which connects the foot pedal with the axle of the wheel such that depression of the foot pedal moves the link and so causes linear movement of the axle and of the at least one pinion along the rack, the at least one pinion cooperating with the rack to translate linear movement of the axle into rotational movement of the wheel.

One end of the link may be pivotally connected to the foot pedal.

The other end of the link may be connected to the axle such that the axle is free to rotate.

The mechanism may comprise means for reversing the direction of linear movement of the axle on release of the foot pedal.

The reversing means may comprise a spring.

The spring may be a tension spring connected between the foot pedal and the link.

The at least one pinion may comprise a freewheel mechanism. This is particularly useful in ensuring that reverse linear movement of the axle is not translated into rotational movement of the wheel.

The axle may comprise two pinions, one at either end, each of which co-operates with a rack.

The invention further provides vehicles such as a scooter, a roller skate, and a roller blade comprising at least one drive mechanism according to the invention. Embodiments include a double- wheel scooter incorporating two drive mechanisms according to the present invention. For the present purposes, roller-skates, roller blades and such like are considered to be vehicles, being designed to convey their wearer.

The invention will now be illustrated, by way of example, with reference to the accompanying drawings, of which:

Figure 1 shows part of a drive mechanism according to the invention;

Figure 2 shows a scooter comprising the drive mechanism of Figure 1;

Figure 3 shows a roller blade comprising the drive mechanism of the present invention; and Figure 4 shows a double- wheel scooter comprising the drive mechanism of the present invention.

The drawings show a drive mechanism 1 for a wheel 2 comprising an oscillatory foot pedal 3, and a link 4, which connects the foot pedal 2 with the axle 5 of the wheel 2 such that depression of the foot pedal 3 moves the link 4 and so causes linear movement of the axle 5, the axle 5 comprising a pinion 6 which co-operates with a rack 7 to translate linear movement of the axle 5 into rotational movement.

The drive mechanism 1 is part of a scooter 8, with the wheel 2 forming the rear wheel of the scooter 8. The scooter 8 also comprises a front wheel 9 on which is mounted a T- shaped handle bar 10. A platform 11 is connected to the handle bar 10 by a bar 12. The platform 11 is rectangular in shape and has a rectangular cut out 13 at its far end.

The foot pedal 3 is pivotally mounted on the platform 11 close to the handle bar 10 at an angle of approximately 45° to the platform 11. The link 4 is an elongate member, one end of which is pivotally connected to the free end of the foot pedal 3, and the other end of which projects through the cut out 13. This end of the link 4 includes an aperture 14. The axle 5 of the wheel 2 passes through this aperture 14 such that the wheel 2 is free to rotate. A pinion 6 is mounted on either end of the axle 5. Each pinion 6 co-operates with a rack 7 mounted on the platform 11 on either side of the cut out 13. A tension spring 15 is connected between the foot pedal 3 and the link 4.

The user stands on the scooter 8 with one foot on the platform 11 and the other foot on the foot pedal 3. When the user depresses the foot pedal 3, the end of the link 4 which is connected to the foot pedal 3 moves down and pivots so that the other end of the link 4 moves out, so causing linear movement of the axle 5 towards the rear of the scooter 8. The pinions 6 on either of the axle 5 translate the linear movement of the axle 5 into rotational movement, thereby rotating the wheel 2. When pressure is released from the foot pedal 3, the spring 15 pulls the link 4 back towards its start position so reversing the direction of linear movement of the axle 5 and returning the wheel 2 to its start position.

Each of the pinions 6 includes a freewheel mechanism such as a ratchet (not shown) so that the rotational movement of the pinion 6 is not transmitted to the axle 5 while the wheel 2 is being returned to its start position.

As can be seen from Figure 2, scooter 8 comprises a single drive mechanism according to the present invention. Figure 3 shows a roller blade 20 comprising a drive mechanism 1. Figure 4 shows a double- wheel scooter 30, having two rear wheels 31,32, each of which is driven by a separate drive mechanism 1. In use, a rider stands on the pedals, alternately pushing them down in order to propel the scooter forwards.