Abstract: A hoist comprises a housing carrying a fixed and slidable sheave set which are engaged by a rope. A piston and cylinder combination are connected to the slidable sheave set for moving it and thus moving a load connected to the rope. The piston has a threaded rod connected to the displaceable sheave set which carries a threaded nut. The axial movement of the nut is restrained by a sleeve which permits rotation of the nut with axial movement of the rod. If the axial movement of the rod accelerates above a selected limit, for example when the load is abruptly removed from the rope, the nut moves against a friction surface in the sleeve to brake the rotation thereof and thus brake the axial movement of the rod.