Patent GB-1046269-A (GB)
Title: Advanceable roof support assembly
Inventor: POTTS MICHAEL CHARLES
IPC: E21D23/16
Filed: 1963-09-03
Abstract: 1,046,269. Advancing mine roof supports. DOWTY MINING EQUIPMENT Ltd. Aug. 28, 1964 [Sept. 3, 1963; Nov. 19, 1963], Nos. 34818/63 and 45634/63. Heading F1P. An advanceable mine roof support assembly comprises a series of advanceable fluid pressure operated roof supports having support props 4, each roof support, Fig. 3 (not shown), having a first valve assembly 15, 16, 17 operable when a line 27 is pressurized to cause its support to advance, and a second valve assembly 33 operable to pressurize either the line 27 associated with the preceding roof support to thereby initiate its advance or the line 27 associated with the next roof support to thereby initiate its advance. Each roof support is advanced by a jack 6 connected to a conveyer which extends along the working force of the mine and is itself advanced by jacks 7 associated with every fourth support. Each roof support is connected to a supply line 9 through a branch supply line 11, a return line 12 through a branch return line 13 and to the adjacent roof support by a signal line 14. Each first valve assembly comprises a prop release valve 15, a prop re-setting valve 16 and a conveyer advance valve assembly 17. Each second valve assembly 33 comprises valves 42, 43, 51, 52. In operation, assuming all the roof supports are set against the roof, each jack 7 in turn is pressurized through a line 36 to cause the conveyer to be advanced. Pressurization of line 36 is effected by manual or automatic actuation of a lever 37 to open a valve 34 allowing fluid to pass from branch supply line 11, through a safety valve 29 opened by a satisfactory roof supporting pressure in the props 4, into a line 32 to pass therefrom through the valve 34 and a ball valve 39 in a piston valve 41 to the line 36. Extension of the jack 7 also extends the jack 6, fluid being discharged from the contracting sides thereof through a line 64 and a piston valve 68 into the branch return line 13. A latch 38 maintains the lever 37 in the actuated position. To initiate the advance of a roof support a lever 46 associated with the second valve assembly 33 in an adjacent roof support is manually operated in a clockwise direction in the adjacent left hand support or in an anti-clockwise direction in the adjacent right hand support. Operation of the lever 46 in an adjacent support opens either of its associated valves 42 or 43, and provided its safety valve 29 is open the signal line 14 leading to the support to be advanced is pressurized. Assuming the signal line 14 from the adjacent left hand support is pressurized, the valve 51 opens thereby pressurizing a line 27 which initiates three operations. Firstly, the latch 38 is released and valve 34 closes so that jack 7 stops advancing the conveyer. Secondly, a release actuator 26 is operated to move a lever 24 which opens the release valve 15 so that the props 4 are released from the roof. Thirdly, the jack-contracting sides of jacks 6, 7 are pressurized from line 27, through the line 64, and a ball valve 67. Pressurization of the jack 6 advances the support, which, when fully advanced, opens a valve 71 resulting in pressurization of a line 30 from the line 64. Pressurization of the line 30 operates an actuator 28 to move the lever 24 to a position which closes the release valve 15 and opens the setting valve 16 to reset the props 4 against the roof. The handle 46 on the adjacent left hand roof support is thereafter allowed to return to its neutral position to allow the valves of the advanced roof support to return to their original positions. Thus valve 51 closes and line 27 drains through a portion of line 64 and a restrictor 69.