Abstract: A system for loading and unloading a vehicle, including: a vehicle actuated wheel chock positioning device for at least one tire of such a vehicle which is rotatable on a treadway between an initial position and a plurality of operating positions, the chock positioning device including a mechanism engageable by such tire at the initial position and movable with the tire as it rolls on the treadway, a chock positionable behind the tire when the mechanism is in any of the operating positions in response to engagement of the mechanism by the rolling tire, and a controllable lock capable of selectively locking the chock in a chock position behind the tire corresponding to one of the operating positions, the system, in one preferred embodiment further including a leveling ramp carrying the chock positioning device with the ability vertically position the device and a vehicle chocked thereby to a selectable vertical position.

Abstract: An assembly for a truck at a loading bay includes a guide track and a chock member for the truck which is reciprocated along the guide track to engage the rear wheels of the truck and lock it securely in position; the guide track may be formed in a platform forming part of the assembly and on which the truck is supported; suitably the platform is hinged at its outer end whereby the platform is pivotable about the outer end such that the rear of the truck may be elevated or lowered for alignment with the loading bay.