the disclosed safety latch is operable with automotive hoists that have a rack gear connected to and movable with the hoist piston . the piston , which carries the hoist superstructure , is disposed in a cylinder so that the piston telescopes to raise and lower the hoist in response to hydraulic or pneumatic pressure acting thereon . a pinion gear mounted on the latch is in engagement with the rack and , through a slip clutch mechanism , drives an operating lever that is connected with a latch dog for securely engaging the rack to prevent movement of the rack and the piston downwardly with respect to the cylinder . the latch operating mechanism can be operated manually to completely disengage the latch dog from the rack whereby the hoist may be lowered . the slip clutch mechanism is provided with a lost motion coupling member between the latch operating member and the latch dog so that the latch dog remains in engagement with the rack should the system for raising the hoist become inoperative .