| 摘要 |
FIELD: mining.SUBSTANCE: present invention relates to a collapsible prop of mine timber. The proposed collapsible prop comprises a first metal pipe extending from the base of mine opening, having a first part with a smooth first outer diameter and a second part with a second outer diameter. And the second part comprises at least one metal roller welded to the first part, and a metal ring welded to the first part. The height of the second part from the first is greater than inner diameter of the second pipe by at least 0.15 inches (4 mm). The yield limit of the first pipe is greater than the yield limit of the second pipe. The second metal pipe is located near the first part and extends to the roof of the mine opening, and when the second pipe receives a load from the roof of mine opening, the second part deforms the second pipe and expands the second pipe, creating resistance to the load from the roof of mine opening.EFFECT: method of creation of timber of the roof of mine opening and construction method of collapsible mine prop is proposed.18 cl, 15 dwg |
