To switch on the first line, operating six cylinders, lever 1 of three-position directional valve 2 is turned, and lever 3 of spool-type directional valve 4 is put into the working position. Fluid is delivered by pump 5 to the six cylinders of the first line, actuating their pistons and clamping the workpieces. After this, the pressure in the first line increases and actuates buttons 6 and 7, engaging the feed of the machine tool. At the end of the machining operation, lever 3 is turned, pump 5 begins to discharge fluid to the tank, pressure in the first line drops and the feed is disengaged. The pistons of the first line are retracted by springs and the fluid is discharged to the tank. To switch on the second line, operating four cylinders, lever 1 of directional valve 2 is shifted to the second position, and the lever of spool-type directional valve 8 is put into the working position. To switch on both lines, lever 1 is shifted to the third position, and both valves, 4 and 8, are put into the working position. Relief valves 9 and 10 protect the system against excess pressure. Check valves 11 and 12 prevent the fluid from being discharged during operation.
$4291$CHP,GC$