Patent ID: 6901842

Claim:
A percussive hydraulic apparatus comprising a body ( 2 ) containing a cylinder in which theta is slideably mounted an impact piston ( 1 ) for striking a tool, driven hydraulically back and forth by an incompressible fluid, the movement of the piston being controlled by a distributor ( 15 ) which, arranged coaxially with respect to the impact piston, is mounted inside a distribution box ( 3 ), characterized in that: the distribution box ( 3 ) comprises a part interfering axially with the piston ( 1 ) and arranged concentrically with respect to the latter, and the distribution box ( 3 ) delimits with the piston a control chamber ( 13 ) which, subjected in succession to the high ( 9 ) and to the low ( 12 ) pressure of the fluid, is in communication via a duct ( 16 ) formed in the distribution box ( 3 ) with a chamber ( 14 ) commanding the movement of the distributor ( 15 ) to create therein alternately a low pressure and a high pressure and therefore a sequence reversal of the resultant of the forces applied to the distributor ( 15 ).