Forklift truck lifting frame - has rear rope fall producing bending moment opposed to that caused by load

摘要

The lifting frame is for a forklift truck etc, extending vertically and with pulleys at the top over which a rope is reeved to the lifting slide. The rope forms one or more falls between the pulleys and the slide, andone or more second ones between the pulleys and a point to the rear of the frame. The second fall extends vertically, sufficiently far to the rear of the frame (M) for the maximum load on the slide to produce a bending moment in the frame below the point, at which the load acts, of between 70 and 130% of that above it, and in the opposite direction.