GB1115463A - Mining apparatus - Google Patents

Abstract

1,115,463. Advancing mine roof supports. DOWTY MINING EQUIPMENT Ltd. Nov. 25, 1965 [Dec. 7, 1964], No.49755/64. Heading F1P. Mining apparatus comprises a series of advanceable hydraulic mine roof supports 1,2,3 (one shown), each having a first valve assembly 5, 6 operable to cause its associated support to perform an advancing operation and at least some of which having a selector valve assembly 13 which when supplied with pressure fluid through a signal line 12 from a different support is manually actuable to cause in one position conveyer advancing jacks to be operated and in a second position to cause the operation of the associated first valve assembly 5, 6. The supports having selector valve assemblies 13 act as master roof supports for slave supports disposed between adjacent master supports. In operation the selector valve assembly of the first master roof support of the series is actuated to open and hold open a valve 15. A second valve assembly 17 provided on each master support is then actuated in the next master support of the series to open a valve unit 18 and thus connect the signal line 12 leading back to the first master support to be pressurised from a main pressure line 8. On arrival at the first master roof support, the pressure in signal line 12 passes through the previously open valve 15 to a line 11 connected to the conveyer advancing jacks of the pair of slave roof supports on opposite sides of the first master roof support. When the conveyer has been fully advanced the selector valve assembly is moved to its other position thereby opening and holding open valve unit 14 and closing valve unit 15. To cause the first support to advance, the second valve assembly 17 of the second master support is again actuated to send a second pressure signal along the signal line 12 whereby a line 7 is pressurised through the previously opened valve unit 14 to cause the support to advance by appropriate operation of the first valve assembly 5, 6 as described in Patent specification 1, 023,478. When the support has satisfactorily advanced the resulting build up in support pressure opens a control valve 26 to cause pressurisation of a pilot line 27 leading to the adjacent slave supports. The slave supports not previously advanced automatically advance in turn on pressurisation of the pilot line 27. The second and subsequent master supports and the slave supports controlled thereby are advanced in a similar manner.