Abstract: An apparatus for guiding a threaded spindle in rotation, which spindle is used to ensure the displacement in translation of a mobile element connected to a threaded female piece engaged on this threaded spindle, which threaded spindle has a certain length and is connected, by one of its opposite ends, to a motor device for driving in rotation about its longitudinal axis in such a way as to allow the displacement in translation of the threaded female piece, wherein this apparatus includes at least one device for elastic absorption of an axial force which force, directed axially with respect to the threaded spindle and toward either one of its opposite ends, arises between this threaded spindle and the threaded female piece, and which force, when exceeding a certain limit, is considered likely to distort in particular the surfaces by which the threaded spindle and the threaded female piece cooperate.

Abstract: The present invention comprises a support frame secured within the cargo box of a pick up truck. The frame supports a drive train comprising a differential driven by an motor. One differential shaft drives a first cable winch while the other shaft incorporates a clutch to drive a second and third winch either independantly from each other or in unison. A system of pulleys ensures that cable wind on the first and second winches is toward the front of the cargo box while on the third winch it is toward the rear. The cable ends are secured to a cargo platform. When the electric motor is engaged the first and second winches are rotated, in a counterclockwise direction which winds the cable into the winch body. The retracting cable first raises and then draws the platform onto the frame. During this process the third winch freewheels and releases cable as necessary. Unloading the platform requires that the clutch mechanism is engaged to couple the second and third winches together.