GB1324138A - Hydraulic distributor valves - Google Patents

Abstract

1324138 Valves BERGWERKSVERBAND GmbH 19 April 1971 [24 March 1970] 24343/71 Heading F2V A distributer valve, particularly for controlling the movement of an advancing pit prop system, has a pressure supply port 43, an exhaust port 74, and a port 59 leading to the pit prop, valve members 11, 12 engageable by piston rods operated by annular pistons 19, 20, 21, 22 in tubular chambers 23, 24, 25, 26, a central chamber 35 connected by a bore 56 to atmosphere, a first passage 45 connecting one or more of the tubular chambers to the pressure supply port 43, a second passage 61 connecting one or more of the tubular chambers to the port 59 leading to the pit prop, and a third passage 72 connecting one or more of the tubular chambers to the bore 56, each piston having the same diameter and the same effective area as the cross-sectional area of the piston rods and the surface area of the valve members delimited by their seats. The supply pressure from the port 43 acts through the passage 45 on the pistons 20, 22 so that only the force of a spring 28 opposes the opening of the valve 12 by a fluid-actuated piston 10. Pressure from the port 59 is similarly applied to pistons 21, 19 so that opening of the valve 11 by a second fluid actuated piston 9 is opposed solely by a second spring 27. The bore 56 collects leakage from the system in addition to providing a connection to atmosphere for some of the tubular chambers. A further passage 76 may be connected to measuring instruments. In an alternative construction, the chambers are formed by annular inserts and interchangeable plugs (such as 79, 82, Fig. 2) allow the valve to be connected with a high or low-pressure supply. Plungers (88) permit hand operation of the pistons (9, 10) and rotatable cores (92) permit selective interconnection with other valves in a series. In a further construction, the piston rods projecting into the chamber 35 are rigidly coupled and only one actuator for the valves is provided.