| 摘要 |
A foot plate (3) can be moved backwards and forwards along two side rails (4), causing a belt (5) to rotate a front wheel (1) in a direction urging the ski in a forwards direction. The belt forms part of a transmission system with gears, containing a belt wheel (6) and a first diagonally cut gear wheel (8) on the same axle. The first gear wheel cooperates with a second neutral gear wheel (9) capable of limited axial movement. Momentum is transferred from the second gear wheel to the front wheel via a second belt (12) and further belt wheels (11, 13). The angled teeth in the first gear wheel ensure that when the foot plate is moved backwards the second gear wheel is pressed against a friction plate (10) to one side of the front belt wheel (13) for the second belt, in order to drive the latter. As the foot plate is moved forwards, pressure is released from the friction plate, so that the second belt is no longer being driven. Using different diameter belt wheels associated with the same belt ensures that a slight backwards movement of the foot plate will generate a relatively large forwards thrust of the ski. |
