GB1175833A - Hydraulic Mine Roof Supports - Google Patents

Abstract

1,175,833. Mine-roof supports. GULLICK Ltd. 14 Nov., 1966 [16 Nov., 1965], No. 48550/65. Heading E1P. A mine-roof support comprises a canopy 16, Fig. 1, which is pressed upwardly by a plurality of pairs of hydraulic props or legs 15 that are capable of restricted pivotal-movement relative to the canopy and a pair of base units 10, 11, backward horizontal-movement of the canopy relative to said units e.g. during advancement of the support, being prevented by a hydraulic pulling-jack, or ram, 19 pivotally attached at one end to a bracket 21 on the canopy and at the other end to a bracket 20 on the unit 10. The jack may be controlled automatically by a valve 25, which is actuated by one of the hindmost legs when the canopy is displaced in a backward direction, opening of said valve causing the jack to exert a tensile force on the bracket 21. Alternatively, or additionally, the jack 19 is controlled by general-control valve-gear 26 for the support. As another alternative, the valve 25 is dispensed with and the jack 19 connected hydraulically to the pulling side of a ram 22 for advancing the support so that the legs 15 are automatically biassed forwardly during advancement. A conveyor C is attached to one end of the ram 22, as shown. In a second embodiment, Fig. 2, the leading end of the canopy is supported by a pair of raked hydraulic-legs 28 and the jack 19 is controlled by valves 32, 33 that are actuated by one of a further pair of hydraulic legs 29, these valves causing the jack to either push or pull so as to oppose forward or backward horizontal movement of the canopy relative to a base unit 27.