Percussion mechanism

Fluid-actuated percussion mechanism includes a housing with an internal cylindrical space receiving a reciprocating piston dividing the space into a working stroke chamber and an idle stroke chamber. The mechanism further includes distributing means mounted in the housing and communicating the chambers and the source of the working fluid. The housing also accommodates a work-performing member adapted to receive impacts from the piston. The distribution means includes at the inlet of at least one of the chambers a valve made in the form of a resilient element. The surface of the distribution means has made therein valve seats of which the number corresponds to that of inlets for supplying the working fluid into the chamber. The resilient valve element is taut about the surface of the distribution means in opposition to the inlets and almost encircles the periphery of same, the resilient element defining by the internal surface thereof with the valve seat, and by the external surface thereof with the housing at least one inlet passage for supplying the working fluid to the inlets. The disclosed structure of the valve, of the distribution means and of the housing enables to increase the total flow area of the passages through which the working fluid is supplied to the inlets of the chambers and thus to step up the power output of the percussion mechanism.