A jack assembly including a telescopic column driven via a gear box, wherein: the gear box is coupled to a rotary input of a drive mechanism that extends and retracts the column; the gear box has only a single input gear and a single output gear that is coupled to the drive mechanism; and the input gear has a connector adapted to be engaged and driven by a portable, hand-held power tool. A jack assembly with a gear box for use as a jockey wheel for attachment to a towed vehicle, to raise and lower a draw bar of the vehicle is also provided.
1. A jockey wheel including a telescopic column for attachment to a towed vehicle, to raise and lower a draw bar of the vehicle, wherein the column includes: a drive mechanism with a rotary input that rotates to cause the column to extend or retract; and a gear box with a rotary connector adapted to connect to and be driven by a power tool, wherein the gear box comprises an output gear having a socket that drives the rotary input so as to provide for geared operation of the drive mechanism, wherein the gear box is mounted over a top end of the column such that the socket of the output gear fits over and engages the rotary input, wherein the output gear and the rotary input have a common rotational axis, and wherein the rotary connector has a rotational axis that is parallel to the common rotational axis.
2. The jockey wheel of claim 1 , wherein the rotary input is located at one end of the column and the gear box includes a housing that sits over the one end of the column such that the rotary input connects with the output gear of the gear box.
3. The jockey wheel of claim 2 , wherein the jockey wheel fitted with the gear box is portable and demountable from the draw bar.
4. The jockey wheel of claim 2 , wherein the gear box further includes an input gear coupled to the rotary connector.
5. The jockey wheel of claim 2 , wherein the rotary input has a square thread for receipt in a corresponding socket of the output gear and the input gear includes a square shaped socket for receipt of a bit of the power tool.
6. The jockey wheel of claim 2 , wherein the rotary input includes a pin to lock the output gear onto the rotary input.
7. The jockey wheel of claim 1 , further including a coupling at a lower end of the column for connection with a mount of a wheel.
8. The jockey wheel of claim 7 , wherein the coupling includes a release pin to rotatably hold the mount to the column.
9. The jockey wheel of claim 1 , wherein the column has a series of ribs at spaced locations along an extent of the column, to engage in a clamp for securing the jockey wheel to the draw bar of the vehicle.
10. The jockey wheel of claim 9 , wherein the column has at least three ribs.
11. A kit of parts, including a jockey wheel, as claimed in claim 1 and a bit for a power tool to couple with the rotary input.
12. The kit of claim 11 , further including a stabilizing plate fitted with a mount which can be connected in place of a wheel of the jockey wheel.
13. The kit of claim 11 , further including a handle for manual operation of the drive mechanism.
14. The kit of claim 13 , wherein the handle is adapted to connect to the rotary connector of the gear box.
15. The kit of claim 13 , further including an adapter to connect the bit to a rotary drive of another device of a vehicle.
16. The kit of claim 11 , further including a power tool and battery pack that are configured to rotate the bit for the power tool.
17. A vehicle to be towed including the jockey wheel of claim 1 , fitted to a drawbar of the vehicle.