When lever 1 is turned counterclockwise, valve spool 2 is shifted to the right. At this, pump 3 delivers fluid through check valve 11 to the upper end of power cylinder 4, moving piston 5, to which roller 6 and member 7 are linked, downward. This turns lever 8 about fixed axis A, clamping work 9. Fluid from the lower end of cylinder 4 is discharged through the directional valve to the tank. Relief valve 10 maintains the required fluid pressure in the system. To release the work, spool 2 is shifted to the left by lever 1, admitting fluid to the lower end of cylinder 4.
$4285$CHP,GC$