Improvements in and relating to steel props for supporting the roof in coal mines and the like, and to releasing means thereof

摘要

447,550. Pit-props. TAYLOR, E., 9, Ravensworth Crescent, Low Fell, Gateshead, and NEARY, R. B., 22, Frederick Street, Coundon, Co. Durham. Nov. 30, 1934, No. 34375. [Class 20 (ii)] A steel pit-prop comprises an upright 1, preferably of H-section, cut near the upper end at an angle such that the upper part 2 may slide off the lower part 1, when released by rotation of a U-clasp 4 pivoted to the lower member at 3. The clasp is formed so that the arms of the U act as guides for the upper member and prevent it from moving laterally, and one arm may be extended to form a lever 4b for releasing the prop.