With rotary directional valves 2 and 2' turned to the corresponding position by lever 3, pump 1 delivers fluid to cylinder 4. At this, the fluid moves piston 5 to the right opening the port to pipeline 6 and fluid is delivered through pipeline 6 and valve 2' to hydraulic motor 7. Rotation of the motor is transmitted through gears 8 and 9 to clutch member 10, which is linked to piston rod 11 and can move axially with respect to the gears. Upon further motion of piston 5 to the right, member 10 engages nut 12. Upon rotation of nut 12, jaws 13, linked to the nut through threaded draw-bar 14, move inward to clamp work 15. Relief valve 16 regulates the fluid pressure in the system. When valve 2 is turned, pump 1 discharges fluid to the tank. At this, spring 17 disengages clutch member 10.
$4289$CHP,GC$