SCREW JACK

Screw jack is a simple machine, which can raise a very heavy load through some distance by applying, comparatively, small force at the end of a long lever. The simple design can raise the load through a small distance, in a vertical direction, only. These are also designed to raise the load vertically and then to carry it horizontally for a small distance. Small jacks are found in every automobile toolbox, which are used to lift the automobile for changing the wheels.