GB631747A - Improvements relating to mine roof props - Google Patents

Abstract

631,747. Mine-roof supports. MAVOR & COULSON, Ltd., and JACKSON, D. Jan. 15, 1947, No. 1343. [Class 20(ii)] [Also in Group XXX] Relates to roof props for mines and consists in an abutment prop constructed as a unit comprising mutually transverse components, namely a roof-propping component comprising a cylinder 12 and ram 15 by means of which the prop can be jammed between roof and floor and a pushpull component comprising a cylinder 13 and ram 16 by means of which, using the roof-propping component as an abutment, some other body (e.g. a conveyer 9 or another prop) can be pushed or pulled from place to place and also by means of which the roof-propping component, when freed, can be pulled towards or pushed from an anchorage in the mine. The cylinder and ram components are operated by pressure fluid stored in a vessel 21 formed like a jacket round the cylinder 12, the fluid being pumped by a pump 22, with handle 23. from the vessel 21 through a distribution valve 25 and thence to either end of one or other of the cylinder and ram components. By appropriately setting the valve 25 the ram 15 may be extended to support the roof or retracted to be free or the ram 16 may impart a horizontal push or pull, so that the sequence of operations is that the prop is jammed by extending, the ram 15, the conveyer 9 pushed forwards by extending the ram 16, the prop freed by retracting the ram 15 and the prop drawn forwards by retracting the ram 16 and using the conveyer 9 (to which the ram 16 is pin-jointed at 19) as an anchorage, and the ram 15 extended to jam against the roof again. The same sequence of operations may be followed by groups of abutment props at a time. Other abutment props in the rear can be similarly moved by pin-jointing their horizontal rams to eye-pieces 19A on the ends of the cylinders 13. A safety valve is included which opens to discharge pressure fluid from the bottom of the cylinder 12 into the vessel 21 if the roof pressure becomes excessive. The distribution valve 25 also discharges directly into the vessel 21. A larger roof surface may be supported by having two or more vertical cylinder and ram components combined with a single horizontal cylinder and ram component. The Specification also describes a form of conveyer with an open top upper trough above a lower housing, the upper flight of the conveyer running along the trough and the lower flight running inside the housing. Specification 191,102, [Class 20(ii)], is referred to.