| 摘要 |
This invention relates to a yieldable type mine support prop and consists of a sleeve (12) which includes an inward indentation (14) in its wall intermediate its ends to define a constricted throat in the sleeve and a timber pole (10) which is located in the sleeve (12) and which is extruded through the sleeve throat when the support is subjected to a predetermined load in its axial direction. <IMAGE> |
