Patent US 3,945,516

A vehicle load lifting and lowering apparatus, which can be used as a vehicle tail lift to lift and lower loads of up to 8 tons between the level of the ground on which the vehicle stands and the level of the vehicle's load carrying deck, comprises a pair of parallel spaced apart guide columns which can be swung via a deformable articulated linkage towards and away from the vehicle. Runners slidably mounted in equal numbers on each column support between them a load carrying platform, and hydraulic rams power the runners (and hence the platform) up and down the columns during load lifting operations. An arm is secured to the guide column and each articulated linkage so as to be movable from a first, inoperative, position in which movement of the runners along the columns effects only raising or lowering of the load carrying platform, to a second position, in which the arm is locked to one of the links of the articulated linkage and projects into the path of movement of one of the runners so that powered sliding movement of the runners up the columns is transmitted to the linkage to move the guide columns towards or away from the vehicle. In the disclosed embodiment, there are two hydraulic rams, associated one with each guide column and each operable in two synchronized stages.