GB1023478A - Advanceable roof support assembly - Google Patents

Abstract

1,023,478. Advancing mine roof supports. DOWTY MINING EQUIPMENT Ltd. Sept. 3, 1964 [Sept. 6, 1963], No. 35330/63. Heading FIP. Each of a series of advanceable hydraulically actuated mine roof support units 4, Fig. 2 (not shown) is associated with a first valve assembly A - - - F, Fig. 3 (not shown), which when actuated by pressurization of an advance-start line 42 connects a main pressure line 11 through valve c and a line 24 to the roof support advancing jack 7 and each support is also associated with a second valve assembly comprising non-return valves 35 - - 38 connecting said line 42 with a signal line 18 leading to the second valve assembly of an adjacent support unit; said second valve assembly, also including a control valve 41 which together with valves 35 - - 38 serve to prevent pressurization of the signal line 18 of the next unit to be advanced until the control valve 41 is operated. The closure member 44 of control valve 41 is unseated when prop resetting pressure in a line 49 displaces a piston 45 resulting in pressure in line 42 gaining access to a line 43, passing valve 37 and entering the signal line 18 leading to the next unit to be advanced. The member 44 may be unseated manually. The first valve assembly also includes a prop resetting valve 57 the closure member 58 of which is unseated by a trip-actuated piston rod 65 at the completion of a roof support advance resulting in jack pressure being transmitted through a line 62 to close valve F and open valve E whereby main supply pressure from line 13 is admitted through a line 25 and a non-return valve 27 to reset the props 6. Actuation of valves A - - D from the neutral position shown to the position required to extend the conveyer advancing jack 8 is effected by counterclockwise pivotal movement of linked levers 32, 33 which may be effected manually or by admission of fluid pressure to the underside of the operating piston of valve B from a line 71 containing a cutter operated valve (not shown). Valves A - - B are locked by 72 until completion of advance of jack 8 when member 72 is unlocked by signal pressure in line 42 which pressure also lifts the operating piston of valve C thereby closing valves A and C and opening valves B and D. Main supply pressure is thus admitted through valve D to lines 24, 30 to open valve F which allows release of props 6 prior to their advancement by jack 7. After completion of advance valve F is closed by pressure in line 62 and the props re-set which may be effected by manual operation of valve E which connects main supply line 13 to a line 25 leading to non-return valve 27 and the props 6 after which said main pressure in line 49 opens control valve member 44 to connect line 42 to line 43 and allow signal pressure to pass valve 37 and pass along the line 18 leading to the next roof support units to be advanced. Reference has been directed by the Comptroller to Specifications 943599 and 968277.