GB668397A - A method and apparatus for provisionally supporting the working faces of mines or the like - Google Patents

Abstract

668,397. Mine roof supports. GROETSCHEL, K. M. May 5, 1949 [May 5, 1948], No. 12040/49. Class 20(ii) As the working coal face in a mine advances the permanent roof supports or lagging irons are connected to one another consecutively in alignment in the form of a chain and an auxiliary roof support k, h, i, Fig. 1, is laterally and detachably coupled so as to permit pivotal movement about a transverse axis to the forward end d of the lagging iron a fitted last, in order to support the roof adjacent the coal face pending the attachment of the next lagging iron a<SP>1</SP>, the arrangement being such that in its operative position the auxiliary roof support does not hamper the attachment of the hogging iron a<SP>1</SP> to the previous one a and the auxiliary support is removed after such attachment for use in the next advance. The lagging iron a has a forked forward end d, Figs. 1, 3, adapted to receive a tongue g at the rear end of the lagging iron a', which is pivotally secured therein by a pin c. A wedge e engaging the tongue g locks the two lagging irons a, a<SP>1</SP> rigidly together. The auxiliary roof support comprises a pair of two-armed levers h, k detachably carried on laterally projecting tubular pivots I on the end d of the lagging iron a, the pivots l being arranged over the holes b which receive the coupling pin c so that the latter can be inserted for the connection of the lagging irons a, a<SP>1</SP> unhampered by an already attached auxiliary roof support. Holes m in the rear arms k similarly allow the insertion of the wedge e. The forward arms h are extended by U-section bars i screwed to them and the rear arms k are connected by a bridge adapted to bear on the underside of the lagging iron a and comprising a bolt o, clamping jaws q, q<SP>1</SP> and distance piece p, Fig. 2. The oblique slots n in the arms k allow angular adjustment of the arms with respect to the lagging a. Alternative arrangements for securing the rear arms k to the lagging iron a and adjusting means therefore, Figs. 5, 6, 7 (not shown), may be used. The auxiliary roof support can be kept in a position of readiness suspended from the lagging iron a as shown in Fig. 1, adjustment of the bolt o providing sufficient lateral play for the arms k, h to enable them to be readily tilted up and secured on the pivots l. In a modified construction shown in Fig. 4, the lagging irons a, a<SP>1</SP> are coupled together by a simple link connection and the extensions i of the auxiliary roof support are secured to the lagging for angular adjustment, the lagging iron a<SP>1</SP> as a cantilever until it is supported by a prop. The pivotal supporting means and the means for coupling the rear arms k to the permanent lagging iron as shown in Figs. 1, 4 may be interchanged in position or may both be arranged at the rear end of the auxiliary lagging iron, the means for angular adjustment of the latter being then arranged either intermediate its ends or near its forward end.