Pump 1 delivers fluid through valve 2, controlled by lever 3, to the lower ends of cylinders 4. The pressure of the fluid moves the pistons and their rods 5 upward, clamping workpieces 6 by means of levers 7 and 8. At this, the pressure increases in pipeline 9 and actuates button 12 which switches on the feed of the machine tool. At the end of the machining operation, lever 3 is turned so that pump 1 discharges fluid to the tank. The pressure in pipeline 9 and in cylinders 4 drops, and piston rods 5 are returned by springs 10 to the initial position. Fluid from cylinders 4 is discharged to the tank and the workpieces are released. Upon a drop in pressure in pipeline 9, button 12 is returned to its initial position, switching off the feed. The system is protected by relief valve 11 against overloads.
$4290$CHP,GC$