发明名称 |
HYDRAULICALLY CONTROLLED UNILATERAL VALVE FOR POSTS OF ADVANCING MINE SUPPORT |
摘要 |
<p>An hydraulically-controlled non-return valve for the hydraulic cylinders of a walking mine-roof support is provided with a cylindrical valve-closing member which is spring-loaded in the closing direction and is guided in a valve case in a valve housing, the valve-closing member being sealed off therein by means of a seal. A space on one face of the valve-closing member is connected to a circulating duct by way of a stepped bore in the valve case, which bore contains a spring-loaded throttle member having through-flow bores of which one has a throttle-like reduced cross-section. During setting of the hydraulic cylinder pressurized fluid flows past the opened valve-closing member through inclined bores and, by way of the circulating duct, to the stroke space of the hydraulic cylinder. During retraction of the hydraulic cylinder, a control piston in the non-return valve is loaded at the same time as an annular space in the hydraulic cylinder. The control piston thus lifts the valve-closing member from a valve seat so that the pressurized fluid flows back in the reverse direction. The said space bounding the valve-closing member is connected to the throttle member in such a manner that the valve-closing member is not caused to oscillate by the pressurized fluid flowing back during retraction of the hydraulic cylinder.</p> |
申请公布号 |
CS8501161(A2) |
申请公布日期 |
1989.11.14 |
申请号 |
CS19850001161 |
申请日期 |
1985.02.19 |
申请人 |
HERMANN HEMSCHEIDT MASCHINENFA,DE |
发明人 |
KRIEGER KARL,DE;HARTLEB JOCHEM,DE;REINELT WERNER DIPL. ING.,DE |
分类号 |
E21D15/51;(IPC1-7):E21D15/51 |
主分类号 |
E21D15/51 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|