| 摘要 |
<p>A system for loading and unloading a vehicle, including: a vehicle actuated wheel chock positioning device (10) for at least one tire (T2) of such a vehicle which is rotatable on a treadway (S) between an initial position (A) and a plurality of operating positions (A, B) the chock positioning device (10) including a mechanism (15) engageable by such tire (T2) at the initial position (A) and movable with the tire (T2) as it rolls on the treadway (S), a chock (16) positionable behind the tire (T2) when the mechanism (15) is in any of the operating positions (A, B) in response to engagement of the mechanism (15) by the rolling tire (T2), and a lock (30) capable of selectively locking the chock (16) in a chock position behind the tire corresponding to one of the operating positions (A, B), the system, in one preferred embodiment further including a leveling ramp (20) carrying the chock positioning device (10) with means (26) to vertically position the device (10) and a vehicle chocked thereby to a selectable vertical position.</p> |
