HYDRAULIC CONTROL VALVE OF MINE POWERED SUPPORTS Russian patent published in 1998 - IPC

FIELD: distribution of fluid in hydraulic systems of powered supports. SUBSTANCE: hydraulic control valve of mine powered support has body with pressure, drain and working conduits, bore with package of bushings and spring-loaded control valve with pusher and combined elastic sealings for separation of pressure and working , working and drain conduits. Spring-loaded control valve and bore of central bushing are made stepped. Control valve has chamber hydraulically communicating in starting position with working and drain conduits by means of radial windows and combined elastic sealing separating pressure and drain conduits. Combined elastic sealings are mounted for permanent contact with embraced surface of big step of spring-loaded control valve and with embracing surface of smaller step of central bushing. EFFECT: enhanced operational reliability. 1 cl, 3 dwg