GB383340A - Improvements in and relating to colliery chocks and the like - Google Patents

Abstract

383,340. Wedges. RITCHIE, D. M., Nursery Hall, Whitletts, Ayrshire. May 28, 1932, No. 24479. [Class 89 (ii).] Mine chocks of the type having a central member with inclined planes and wedge members coacting therewith, have the inclined planes so disposed that the wedge members on release slide downwardly and inwardly. The wedge members c, Figs. 1 and 4, are held in expanded positions on the members b of the central member by means of bars h which are rotatable on pivots g to release the chock. Alternatively, the blocks c may be held by transversely adjustable locking bars j having slotted fins j<1>, Figs. 9 and 10, which engage recesses in the side bars d, axial movement of the locking bars causing the slots in the fins to register with the side bars so that they may then slide axially of the side bars and release the chock. In a further form, the blocks may be held apart by keyed projections on a rod adapted on axial rotation of the rod to enter slots in the wedge members ; or transverse members n, Fig. 20, in grooves in the side members d acting as stops may be released by interacting wedge members d, o which cause upward movement of an unlocking member o beneath the stops. The wedge surfaces may be formed in steps to allow of a greater range of adjustment.