GB1025879A - Mining apparatus - Google Patents

Abstract

1,025,879. Advancing mining conveyers. DOWTY MINING EQUIPMENT Ltd. Oct. 7, 1964 [Oct. 16, 1963], No. 40892/63. Heading F1P. In a mining apparatus wherein a conveyer is advanced towards the receding working face by a series of fluid pressure operated jacks each jack has an associated valve assembly 9 (Fig. 2, not shown) including a pressure reducing valve 49 and is operable to cause pressurization of a line connected to the next valve assembly 9 to thereby trigger operation of the associated advancing jack, and fluid reduced in pressure by a predetermined amount by passage through the reducing valve 49 of the next valve assembly flows through the reducing valves 49 of successive valve assemblies to cause operation of their associated jacks until the pressure reaching a valve assembly is insufficient to cause operation of its associated jack. Each valve assembly 9 has a handle 16 movable in an anti-clockwise direction if valve assemblies to the right are to be pressurized, or clockwise if valve assemblies to the left are to be pressurized. Assuming the handle 16 of the extreme left valve assembly 9 is moved in an anti-clockwise direction to move a valve member 19, fluid from a pressure line 13 passes through chambers 23, 28, a line 31, and a non-return valve 34 into a line 15 connected to the next valve assembly 9. Pressurization of the line 15 opens a valve closure member 40 in the next valve assembly 9 to pressurize its associated line 12 and cause operation of the conveyor advancing jack controlled thereby. Pressure fluid in the line 12 then flows through the pressure reducing valve 49 where its pressure is reduced by a predetermined amount before pressurizing a further line 15 connected to the next valve assembly 9 which thereafter operates in an identical manner to the valve assembly described. Hence each successive valve assembly is supplied in turn with a reduced pressure supply, so that ultimately the pressure supplied to the line 12 associated with a particular valve assembly 9 is insufficient to operate valves A, B (Fig. 3, not shown) controlling operation of the advancing jack. Each assembly 9 also includes a non-return valve 34, a pressure reducing valve 48, a valve closeure member 44 and a valve member 18 arranged to allow the series of jacks to be operated in the opposite direction.