A hoist includes two lift columns with a base for supporting the upright on a floor, the base projecting to a working side of the upright and a lift arm mounted for sliding movement up and down along the upright with the lift arm projecting to the working side of the upright. A safety mechanism, for limiting movement of the lift arm slide downwardly along the upright towards the base, has an upright rack and a latch engageable with teeth spaced along the rack with an upper cross member coupling the uprights of the two column assemblies at a position spaced above the bases thereof; and a lift mechanism for simultaneously raising and lowering the lift arm slides along the respective uprights.