Abstract: A machine having a housing wherein are arranged a stepped hammer piston adjoining the front portion of the machine and a stepped plunger adjoining the rear portion of said machine, said hammer piston and plunger being adapted for an axial movement in said housing. The hammer piston and the plunger are separated by resilient means. The pressure fluid fed into the housing provides for reciprocation of the hammer piston and the plunger. The hammer piston reciprocations consist of forward and return strokes. During the forward stroke the hammer piston transmits impacts to the tool. The presence of the hammer piston and the plunger with the resilient member in between increases the power of the hammer piston impacts transmitted to the tool, hence the machine efficiency. The machine may be advantageously used as a hydraulic hammer (quartering hammer) and a hydraulic percussive device for making holes and deep wells in soil.

Abstract: A machine having a housing wherein are arranged a hammer piston adapted for reciprocation in said housing to effect forward and return strokes and a stepped pressure difference ring valve fitted over the hammer piston and also reciprocating in said housing. A tool rotation mechanism is linked kinematically with a gear arranged on an anvil and has at least one twin hydraulic cylinder comprised of two different diameter cylinders and located at the front portion of the machine. The twin hydraulic cylinder is divided by a lateral partition and accommodates a pusher piston which carries a spring-loaded pawl and forms with the partition and the different diameter cylinder barrels two chambers, the smaller diameter chamber being the pressure one, the larger diameter chamber being the return chamber.