Hydraulic drive for impact tool - incorporates work piston with control slide valve with groove to provide hydraulic connection

摘要

The striking tool hydraulic drive has a displaceable piston in a work cylinder, and a displaceable control slide valve in a control cylinder. Between the opposite end of the workpiston to its striking end extends a displaceable control shaft of less cross-sectional surface than the piston and firmly connected coaxially to the work piston. The control slide valve is arranged axially behind the rear end of the piston. A control groove of the control shaft is permanently connected to the hydraulic fluid, and is connected with the larger control surface of the slide valve via a channel towards the end of the work piston back stroke. A working groove of the control slide valve is connectable, dependent upon the axial position of the control slide valve, with the hydraulic fluid or a back flow channel.