| 摘要 |
961,983. Hydraulic pit props. M. VON LINSINGEN, [trading as BOCHUMER EISENHUTTE HEINTZMANN & CO.]. Feb. 9, 1961 [Feb. 19, 1960], No. 4887/61. Heading E1E. In an hydraulic pit prop the inner telescopic piston 16, 17 is provided with a calotte-shaped seating 15 to universally accommodate a sealing unit 6, 7, 11, 12 having a packing adjusting ring 9 screwthreaded thereto, modified forms of universal joint to permit sealing when the parts 1, 16 are misaligned being apparent from Figs. 2, 3, 4 and 5 (not shown). The prop is provided with a combined pressure release- and reliefvalve 4 and has the pressure chamber 8 supplied via an inlet valve 3 or a reservoir in the props communicating therewith through a bolt 8 constructed as a valve-controlled tube. The bearing members defining the universal sealing, the piston and the packing, may be made of synthetic plastic material. |
