Improvements to a hydraulic support for the roofs of mines

摘要

1,086,532. Hydraulic pit props. W. E. & F. DOBSON Ltd. Jan 11, 1965 [Jan. 18, 1964], No. 2315/64. Heading E1E. [Also in Division F2G] Fluid is supplied to the pressure chamber 2 of a mine roof prop (Fig. 1) from an external line to which a hydraulic coupling (Fig. 2) is connected to provide a charging unit for removable plug-in fitment to a prop coupling valve 8 and forms a sealed outlet duct for the fluid at the junction between the outlet passage 18a thereof, and the inlet passage 12 of the valve 8. The sealed passage comprises an annulus 13 around the passage 12 to communicate with the outlet duct 19 between sealing rings 22, 23. A releasable catch 25 locates the unit when connected to the valve 8. The valve 8 leads to a pipe 6 passing through the prop's ram 3 into the pressure chamber 2 of the cylinder through a non-return valve 7, a valve 4 being used for automatic overload relief and manually-operated release of fluid pressure. A roof support (Fig. 3) may have two props with respective coupling valves 8, 8', inter-connected by an advancing cylinder-andram 29, to which a reservoir 32 is connected by pipe lines 30, 31. In the latter there is a coupling valve 8" to connect the charging unit. On the reservoir 32 is a return coupling valve 8"' to connect a return charging unit from the props or cylinder-and-ram 29.