GB754482A - Improvements in and relating to bolt and like anchoring devices - Google Patents

Abstract

754,482. Anchor-bolts. ANCIENS ETABLISSMENTS GOLDENBERG & CIE. April 27, 1954 [April 28, 1953], No. 12097/54. Class 89(1). An anchoring device, e.g. for mine roofs, comprises a rod 1, Fig. 1, provided at one end with an expanding head and at the other end with tightening means, e.g. threads 2 to receive a nut 3, the head including at least two independent shells 15, 16 with separating ramps A, B, C, D co-operating with at least two sets of cams 5, 13 fixed to the rod, the shells being held in position on the rod by yieldable means 20. The shells interengage by tongues 21 and grooves 22,. and are supported by faces 17 engaging the upper side of cams 13, so that teeth 23 on the skirt project for engagement with the wall of bore 25. As rod 1 is drawn out of the bore by turning nut 3, cam 13 first causes spreading of the shells by moving between ramps B, D, until cams 5 engage between ramps A. C, Fig. 5, and the shells are pressed against the bore wall, and tongues 21 leave grooves 22. If further clamping pressure is required the rod may be withdrawn until the lower surfaces 8 of cams 5 engage the tongues 21 and projections 35. Further tightening of nut 3 causes increased deformation of the shells and further penetration thereof into the bore wall. The two or more sets of cams may operate simultaneously or successively, and two or more heads may be provided on one rod. Further cams 10, 11 ease entry of cams 5 between ramps A, C.