Improvements in or relating to roof support devices for roofs in underground mines

摘要

1,016,901. Locks. N. J. MUSCHAMP & CO. Ltd. March 13, 1962 [June 7, 1961], No. 20484/61. Heading E1E. A mine roof support chock assembly as disclosed in Specifications 684,403 and 766,632 is provided with releasable retaining safety means operably associated with the catch members 15, 16 and the remote-control lever means 25, 26, 100, 102 to prevent inadvertent release of the catch members other than by release of the said lever means. When the lever means 25, 26,100,102, are operated to release the catches 15, 16 they actuate subsidiary levers 106, 107 to raise pegs 112, 113 clear of cross-bars 20 of the catches to allow cam ends of the levers 25, 26 to release the catches from the recesses 22 thereby releasing the chocks 11, 12.