HYDRAULIC HAMMER Russian patent published in 1998 - IPC

FIELD: rock-crushing machinery. SUBSTANCE: this is intended for crushing rock, reinforced concrete and other hard materials. Hydraulic hammer has striker with piston having annular protrusion in its end, and two oppositely located rods of different diameter to create two chambers with body: idle stroke chamber which is constantly connected with pressure line and accumulator, and working stroke chamber which by means of hydraulic control valve is alternately connected either with pressure line or with return line. Hydraulic control valve made in the form of three-stage bush and movably located in body coaxially to piston-striker has two control spaces at ends of bush. By means of passages in body it is connected with circular bores in body made in ends of working stroke chamber which are open towards aforesaid chamber. Located between circular bores is annular protrusion of piston-striker. Hydraulic control valve can be made in the form of plunger-spool located in bore isolated from striker or in separate body which simplifies repair and maintenance of hammer. EFFECT: higher efficiency. 5 cl, 5 dwg