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75. 发明专利

GB776555A Pit prop 未知
公开(公告)号：GB776555A
公开(公告)日：1957-06-12
申请号：GB2648254
申请日：1954-09-13
申请人： SCHMIDT ALEXANDER
IPC分类号： E21D15/28 , E21D15/38 , E21D15/502
摘要： 776,555. Pit props. SCHMIDT, A. Sept. 13, 1954 [Sept. 11, 1953], No. 26482/54. Addition to 742,701. Class 20(2) The telescopic pit prop of the parent Specification having two superimposed independent tensioning members 9 is modified by the provision for each tensioning member of a clampmember 7 having a central reduction in thickness so that they are elastically deformed to improve their friction grip. The reduction may be by means of a recess 11 in which the inner prop member 1 fits on a recess 10 on the other side or both recesses. The inner prop member is stiffened by a central web 15 and this member may be formed in two halves with a half web in each or the web may be slid into grooves after the two halves are welded together. The inner prop member is guided by ridges and grooves 20 in the outer prop member. The ridges may be formed by the projecting edges of the central web 15.

79. 发明专利

GB749113A Improvements in or relating to adjustable pit props 未知
公开(公告)号：GB749113A
公开(公告)日：1956-05-16
申请号：GB100953
申请日：1953-01-13
申请人： JOHN CLIFFORD HOLGATE ELLIS
IPC分类号： E21D15/38
摘要： 749,113. Pit props. ELLIS, J. C. H. (Eisenwerk Wanheim Ges.). Jan. 13, 1953, No. 1009/53. Class 20(2). The inner member of a telescopic pit prop comprises two parts 6 which can move independently of each other under roof pressure. The two parts are connected by a cap 5 and are clamped in the prop lock 2 with a friction, plate 8 between them which is mounted in the lock 2 so as to be held against downward movement. The parts 6 are of channel section the channels facing one.another or the channels may be reversed as shown in Fig. 3 the webs of the channels and the friction plate 11 having interengaging ribs and grooves 10, 10a which may be dimensioned so that either the bottoms or sides of the ribs engage the grooves.

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