PNEUMATIC HYDRAULIC SIDE LIFTING JACK

摘要

A side lifting jack having a pneumatically and hydraulically actuated lifting cylinder for raising a lift arm of the side lifting jack. The jack includes a hydraulic fluid reservoir and air pressure is supplied to the hydraulic fluid reservoir to cause hydraulic fluid to be delivered to the lift cylinder. A flow restricting device controls the rate of flow of hydraulic fluid into or out of the hydraulic cylinder and prevents sudden movement of the jack or sudden extension of the lift cylinder assembly in the event that the load on the lift jack is suddenly reduced or removed from the lift jack. The jack also includes a ratch and pawl arrangement to selectively prevent retraction of the piston of the hydraulic cylinder and lowering of the jack.