| 摘要 |
In a pressure-relief valve for hydraulic devices in mining, in particular for hydraulic pit props, a hollow valve piston (2) closed at one end face and open at the other end face is arranged in a cylinder bore (13) of a valve part (1). It is acted upon at its open end face by the hydraulic pressure and is held at its closed end face by an opposing pneumatic-spring piston (5). It has at least one essentially radial passage bore (15) in the operative direction of the hydraulic pressure in front of a sealing ring (14) sitting in the cylinder bore (3). At least one port (19) leads out of the pressure-relief valve behind the sealing ring (14). The valve part (1) having the cylinder bore (13) for the valve piston (2) and a further valve part (4) having a cylinder bore (16) for the pneumatic-spring piston (5) are screwed (3) to one another while enclosing the valve piston (2) and the pneumatic-spring piston (5) between them. They directly form a valve housing, the at least one port (19) which leads out of the pressure-relief valve being an essentially radial bore only in the further valve part (4). The pressure-relief valve can be constructed to be so narrow that it [lacuna] form a construction unit with a setting and release valve and [lacuna] fitted into a working cartridge for a setting and release valve of a hydraulic pit prop ... Original abstract incomplete. <IMAGE>
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