Lifting mechanism with platform - has lower bar of parallelogram linkage extended by ram to swing platform

摘要

Lifting mechanism is for a lorry tailboard, and has two or more bars in parallel planes one above the other and forming part of a parallelogram linkage. The upper bar hinges between the platform and the supporting structure, and the lower one is extensible, pivoting between the platform and the end of an auxiliary lever. The latter pivots at a point between its ends on the structure for a limited amount, and is coupled at the other end to a single-acting hydraulic ram. The auxiliary lever pivot point is below that where the lever acts on the lower bar. The lower bar is extensible from a length equal to that of the upper one so as to swing the platform down into the working position.