Workpiece 6 is located and clamped by master jaws 1 with interchangeable top jaws 2. When piston 3 is moved downward by the action of fluid delivered to the top end of the cylinder, the piston rod pulls sleeve 4 downward, turning levers 5 about fixed axes A to move master jaws 1 toward the centre of the chuck. When piston 3 is moved upward by fluid delivered to the bottom end of the cylinder, jaws 1 are retracted, releasing workpiece 6.
$3889$LHP,GC$