GB1210069A - Improvements in or relating to mining equipment control systems responsive to the passage of a body - Google Patents

Abstract

1,210,069. Mine roof support control systems. GULLICK Ltd. 27 May, 1968 [8 June, 1967], No. 26493/67. Heading E1P. [Also in Division F2] System for controlling the automatic advance of equipment towards a mineral face in a mine in response to the passage of a body along said face, comprising control means for controlling a power supply to advancing means for said equipment and two magnets which are arranged by mutual repulsion to operate a control element in said control means when brought into proximinity one of said magnets being on the body so that it is brought into proximity with the other magnet during passage of said body along the mineral face. An articulated coal face conveyor C is connected to every fourth one 10, 14, 18, 22 and 26 of a number of hydraulic pit props 10 to 28 through the prop advancing rams 29, and is arranged to be snaked along by these rams, which are double-acting, in accordance with the movement of the coal cutting machine M along the coal face F. The machine M carries a permanent magnet 49 which is pivoted at each reversal of the machine, so that a north pole N faces toward a control device in one direction of movement and a south pole S in the other direction. As shown, a control device positioned at each prop comprises a pair of normally open valves 36 carrying permanent magnets 39, 40 of opposite polarity and facing toward the path of magnet 49. These valves are supplied at 33 through restrictions and a pair situated at position 18 along the coal face are connected from their outputs to flip-flops 41 and 42 arranged to operate main valves controlling the advancing rams 29 of the props 10 and 26. In this way the machine is arranged to operate the advancing ram 29 of each eigth props behind it. Electric or electronic switch means instead of the control valves, may be used to control solenoid main valves which operate the rams.