When piston 1 is moved to the left by the action of fluid delivered to the right end of the cylinder, wedge 2, mounted rigidly on the end of the piston rod, pulls sleeves 3 and 4 downward. This turns levers 5 about fixed axes A, moving master jaws 6 with interchangeable top jaws 7 toward the centre by an equal amount. The jaws are retracted by spring 8 when piston 1 is moved to the right by fluid delivered to the left end of the cylinder. Two jaws are conventionally shown instead of three.
$3891$LHP,GC$