Pit prop assembly

Abstract

A pit prop assembly for use in a mine having a floor, a roof, and a face, comprises a pair of pit props having parallel elongated floor-engaging bases on each of which is pivoted a roof-engaging arm which may be pressed against the roof by means of a hydraulic ram extending vertically between each base and the respective arm. A pair of telescoping elements extend longitudinally between these two bases and one of the elements is pivoted at its front and rear end on respective front and rear end of one of the bases and the other element pivoted at its front and rear end on the respective front and rear end of the other base. A longitudinal-displacement ram is provided between these telescoping elements so that the two pit props can be displaced longitudinally relative to each other. In addition a transverse ram forms the connection between the rear of one of the elements and the corresponding rear of the corresponding base so that transverse displacement or swiveling of the two pit props is also possible.

Dependencies are inferred from the claim text.