Hydraulic programme control system for anchoring apparatus situated at the ends of conveyors in mines and for self-advancing mine roof supports

摘要

977,715. Endless conveyers. GEWERKSCHAFT EISENHUTTE, WESTFALIA. April 24, 1961 [April 25, 1960], No. 14798/61. Heading B8A. [Also in Divisions E1 and F1] A conveyer 10 and associated coal-winning machine may be adjusted in two directions at right angles relative to hydraulically operated prop Groups B and C on a frame 12, by the action of hydraulic jacks 20, 21. The conveyer is then held by its own prop group A while the groups B and C are released and the frame 12 moved to a fresh position by further action of the jacks 20, 21. Activation of the props and the jack 20 is effected by a control valve (Fig. 3, not shown). The activation of the jack 21 is effected by a separate control. A regulating valve assembly {see Division F1) ensures that the pressure from the jacks of the group A can only be released by the operation of valves which are motivated by the pressure maintaining the jacks B and C in supporting position. Similarly the pressure applied to groups B and C cannot be released without maintaining the pressure applied to group A. When pressure is applied to groups B and C a pressure build-up of 50 atmospheres is reached whereupon further pressure supply to group B is prevented until the pressure in the jacks of group C reaches 150 atmospheres.