| 摘要 |
A jacking system for supporting the front end of the trailer of an articulated truck when uncoupled from a tractor unit comprises an externally screw-threaded inner jack member (16) and nut segments (18), capable of cooperating with the screw thread on member (16). The nut segments (18) are mounted on a tubular outer member (14) mounted on the underside of the trailer bed (10) for rotation about a vertical axis by means of a handle (44). The nut segments (18) are movable on member (14) between operative positions in which they engage the screw thread on member (16), to inoperative positions in which they do not. When the trailer is coupled to a tractor unit, the member (16) is held in a raised position. When it is desired to uncouple the trailer unit, the segments (18) are moved to their inoperative positions and the member (16) is allowed to drop onto the road surface. The nut segments are then re-engaged with the member (16) and the member (14) rotated by the handle (44) to jack up the front end of the trailer. When the trailer is to be coupled up to a tractor unit again, these operations are reversed, rapid raising of the member (16) being achieved by a cable (20) and winch (24). |
