Improvements relating to mine roof support for long-wall face workings

摘要

771,721. Mine roof supports. BECORIT GRUBENAUSBAU GES. July 15, 1955, No. 20605/55. Class 20(2) A mine roof support of the advancing bar type for longwall fronts comprises pairs of roof bars kSP1/SP, kSP11/SP capable of being advanced alternatively, each pair of bars being interconnected by vertically swivelling and horizontally slidably displaceable guide members v equal in length to a considerable portion, preferably two thirds, of the total length of each bar. The guide members v are sheet metal bodies having tubular extensions or eye pieces rSP1/SP, rSP11/SP at their edges slidably mounted on metal rods eSP1/SP, eSP11/SP attached to the bars kSP1/SP, kSP11/SP. The rods eSP1/SP, eSP11/SP are detachable and can, be provided on either side of the bars. When the bars kSP1/SP, kSP11/SP are of I-section, skirtings gSP1/SP; gSP11/SP, may be secured to the edges of the flanges fSP1/SP, fSP11/SP to limit the angular deflection of the connecting member v. In operation, the props are removed from the bar to be advanced, allowing the bar to swing downwardly so that it can be pushed forwards with the tubular extensions or eye pieces rSP1/SP, rSP11/SPsliding along the rods eSP1/SP, eSP11/SP.