Invalid hoist

An invalid hoist comprising a mobile chassis, a mast upstanding from the chassis, a lifting arm pivotably connected to an upper end of the mast, the lifting arm having a sling hanger or at least one sling attachment point at or adjacent to one end thereof, a power operated extendible/retractable actuator between the lifting arm and a lower part of the mast, the lifting arm being pivotably connected to the upper end of the mast at a position intermediate its ends and the actuator being connected to the lifting arm on the side of the pivotable connection between the lifting arm and the mast remote from said one end of the lifting arm, and a connecting link pivotably connected between one end of the actuator and one of the lifting arm and the mast so that if the lifting arm meets with an obstruction during a lowering operation, the actuator and link will pivot relative to one another so that the actuator can continue to extend without applying a force to the lifting arm to urge the latter against the obstruction, wherein the connecting link is connected between said one end of the actuator and one of the lifting arm and the mast such that an auxiliary link including a load cell can be additionally and removably connected between said one end of the actuator and one of the lifting arm and the mast, and such that any load then applied to the lifting arm is transmitted entirely through the auxiliary link and not through the connecting link.