Mine roadway yielding support frame - has cutting action members between surfaces of clamped sections

摘要

The mine roadway support frame is formed from yielding channel sections which are overlapped and clamped. Members (20-23) are inserted between the yieldably clamped surfaces (16, 17, 18, 19) of the channel sections (1, 2) and exert a cutting effect on these surfaces. Pref. the members should be embedded in the surfaces of the sections where these are tobe clamped together. The members may be made of hard metal or a mixture containing corundum. The members can be more easily inserted if carried on support strips (20) arranged between the sides (16, 17; 18, 19) of the sections being clamped (1, 2).