发明名称 YIELDABLE TIMBER MINE SUPPORT
摘要 An elongate mine support comprising a timber pole (2) with a metal sleeve (3) reinforcement therearound has circumferential weaknesses (4) in the sleeve for assisting controlled collapse of the sleeve when the support is under axial load. The circumferential weaknesses may be formed between the adjacent edges of separate sleeves (29). The separate sleeves (35) may each be belled at its lower end so as to slip each one over the next lower sleeve during a controlled collapse of the support. The weaknesses (8) may be spirally formed and so as to be capable of being torn off to assist in shortening the support. The weaknesses (44) or (52) may be formed as corrugations.
申请公布号 AU3425384(A) 申请公布日期 1985.04.18
申请号 AU19840034253 申请日期 1984.10.15
申请人 BESTOBELL SOUTH AFRICA LTD. 发明人 DIRK CORNELIUS STEPHANUS VENTER
分类号 E21D15/02;E21D15/14 主分类号 E21D15/02
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