Patent GB-1464557-A (GB)
Title: Fluid pressure apparatus
IPC: E21D23/16
Filed: 1974-04-16
Abstract: 1464557 Modular hydraulic circuits DOWTY MINING EQUIPMENT Ltd 16 April 1974 [30 March 1973] 15392/73 Heading F1P [Also in Division El]  In a longwall mining system, a fluid-pressure circuit assembly includes a pair of body members 61, 63, Fig. 7, each having a flat surface 62, 64 with ports, Figs. 11,9, and the ports communicating with passages in the body members to effect connection to respective fluid-pressure components and a plurality of interchangeable and separately usable circuit members 65 with slots therein, Fig. 10, for effecting connection between ports in the surfaces 62, 64, each circuit member 65 co-operating with the body members 61, 63 to provide a different fluid-pressure circuit for the particular modification of mining system used. In the particular system shown, a longwall mining system includes a plurality of supports 5 arranged along the face 1 and being connected by jacks 6 to a conveyor 2 for the advancement of the conveyor towards the new face as at 4, each support having a control valve assembly 7, each being connected to the assemblies of the two adjacent supports so that each support control valve assembly is able to provide signals to control the adjacent supports. Each support, Fig. 2, has two pairs 13, 14 of vertical jacks, a jack 16 for a cantilever support beam 15 and a jack 17, 18 for conveyor push and support advance. Looking to Fig. 5, valves 21, 22, 23, 34, 38 41 and 42 operate the jacks 13, 14, 16, 18, and fluid-pressure relief valves 31, 32, 33 are also provided. Valves 21, 22, 23 are both manually operable and pilot-operable by pilot cylinders 24, 25, 26, 27, 28, 29. Valves 34, 38, 41, 42 have pilot cylinders 35, 39, 43, 44 working against springs and are also manually operable. Pilot cylinders 27, 28, 29, 35 are simultaneously operable via a line 11C from a shuttle valve 11S which is a simple ball-valve device capable of receiving fluid-pressure in either one of lines 11RA, 11LA from the two adjacent supports, such pressure being then transmitted to the cylinders connected to line 11C to actuate their respective valves. Similarly, shuttle valves 12S, 13S and 14S lead to pilot cylinder 39, pilot cylinders 24 and 25, and pilot cylinder 26 respectively via lines 12C, 13C, 14C, each shuttle valve being operable by corresponding pairs of lines from the adjacent supports. The rotary selector valve 51 is a nine position valve, the controls affected in each valve position being (1R) leg release right, (2R) support advance right, (3R) leg set right, (4R) cantilever set right, (N) Neutral and 1L, 2L, 3L, 4L for the equivalent operations to the support to the left of that being described. Valve 52 is operable to make lines 46, 47 the pressure and drain lines respectively which communicate with the pressure chambers of the jacks according to the position of the pilot-operated valves. Fig. 7 shows the use of body members 61, 63 and circuit member 65 in the circuit of Fig. 5. From the block 61, the hose assemblies 8 extend to the right and left adjacent supports, and the shuttle valves, pilot-operated valves, and relief valves are all detachably mounted as modules on the block 61. The auxiliary block 63 carries a plug 67 which forms the means for connecting a hose assembly 68 to the block 63, the hose assembly 68 extending to the rotary selector valve 51 to enable it to be located in any suitable position. The connections from plug 67 open into the ported surface 64 of block 63. Similarly the ports of surface 62 of block 61 lead to various pipes and valves. The circuit member 65 used is formed of thin steel sheet of approximately À030 inches thick. Each port in the ported surfaces is given a reference corresponding to the line to which it is connected in the circuit. Also each hole and slot in member 65 is assigned the numerals of the ports which it inter-connects. In a slightly modified longwall mining system where essentially different supports are shown Figs. 4, 6, 8 and 12, (not shown), a different circuit member is employed (Fig. 12), which closes off some of the ports previously used and inter-connects others in a different way to provide the required circuit.