GB700002A - Improvements in means for assembling supporting beams - Google Patents

Abstract

700,002. Mine roof supports. PROGRES CHARBONNIER PROCHAR SOC. COOPERATIVE. Aug. 2, 1949 [Jan. 31, 1949], No. 20126/49. Class 20 (2) A beam which forms part of a pit support and which is adapted to be pivotally attached at one end to one end of a similar beam supported against the roof of the working and which is then raised about the pivot and locked into position against the roof, comprises a beam formed by spaced longitudinals a, Figs. 1 and 2, between which are secured a jaw-forming end member b and a similar but bifurcated jaw-forming end member b<SP>1</SP> the members, b, b<SP>1</SP> having, respectively, holes c, c' and hooks d, d'. The bifurcated member b' of one beam is engaged with the member b of the adjacent beam and a pivot pin e is passed through the holes c, c<SP>1</SP>, the unsupported beam then being raised about the pivot e until it engages the roof in which position it is locked by a key f, Fig. 3, driven between the opposed hooks d, d<SP>1</SP>. The cheeks of the key and the co-operating faces of the hooks have the form of a helicoid or other ruled surface adapted to ensure contact over the entire extent of said surfaces whatever the relative angular positions of the beams and the degree of engagement of the key. Specification 652,701 is referred to.