Abstract: In a control method for a power assist apparatus, a pressing force acting on a workpiece held by a workpiece holding apparatus is detected, a determination is made as to whether or not the detected pressing force exceeds a preset threshold, a determination is made as to whether or not a dead man switch provided on the workpiece holding apparatus is ON, and a determination as to whether or not to release a rotation restriction applied to a joint portion for connecting the workpiece holding apparatus rotatably to an arm is made in accordance with a result of the determination as to whether or not the detected pressing force exceeds the preset threshold and a result of the determination as to whether or not the dead mean switch is ON.

Abstract: A wheel driving device for a loader including a belt type transmission unit adapted to selectively drive wheels of the loader in a normal or reverse direction by power transmitted from an engine to a power transmission unit, the belt type transmission unit having forward and rearward belts for driving the wheels in normal and reverse directions, respectively, clutch type levers respectively mounted on the case at opposite sides of the case, the levers being adapted to selectively apply pressure to the forward and rearward belts, thereby operatively connecting the forward and rearward belts to the wheels, respectively, and hydraulic cylinders each adapted to hydraulically switch each lever between a position where it applies the pressure to each corresponding belt and a position where it releases the pressure applied to the corresponding belt.