| 摘要 |
953,573. Hydraulic apparatus. BWG BERGWERKUND WALZWERKMASCHINENBAU G.m.b.H. Sept. 20, 1961 [Sept. 22, 1960], No. 33670/61. Heading F1P. An arrangement for setting, hydraulic mine construction members 6 comprises branch pipes 2, 21, 2<SP>11</SP> which connect a main supply pipe 1 to the members and are each provided with a non-return valve 3, 31, 311 bridged by a parallelconnected high pressure pump 4, 4<SP>1</SP>, 4<SP>11</SP> having a low-delivery capacity. The construction members are in the form of pit props and are extended during setting by the pressure in the main supply pipe, which pressure may be static or provided by high-delivery low-pressure pumps. The load on the props is taken up by the high-pressure pumps which are either switched off or switched to pressureless circulation when a predetermined pressure is reached. The high pressure pumps may be mounted on a sliding carriage on a face conveyer means so as to advance therewith. |
