Anchor bolt assembly

Claim 1

An anchor bolt assembly arranged to be inserted into and anchored within a borehole and including an anchor bolt and an expansion sleeve mounted on said anchor bolt, said anchor bolt having a leading end first inserted into the borehole and an opposite trailing end, said anchor bolt comprises an axially extending cylindrically shaped body extending from the trailing end toward the leading end, an axially extending frusto-conical part extending from the leading end toward the trailing end with the maximum diameter of said frusto-conical part being substantially the same as the diameter of said cylindrically shaped body, said frusto-conical part tapering inwardly in the direction from the leading end toward the trailing end, an axially extending reduced diameter part extending from said cylindrically shaped body to said frusto-conical part and having a diameter substantially the same as the minimum diameter of said frusto-conical part, wherein the improvement comprises an axially extending expansion sleeve extending continuously around and arranged to be fitted onto said reduced diameter part with the axis of said expansion sleeve extending in the direction of the axis of said anchor bolt, said sleeve having at least one web extending for a part of the circumferential direction of said sleeve and in the axial direction of said sleeve for the full length thereof and said web being deformable relative to the remainder of said sleeve, said web having a wall thickness in the radial direction of said sleeve considerably less than the corresponding wall thickness of said sleeve, said expansion sleeve being deformable from a first condition to a second condition with said expansion sleeve in the first condition having a cylindrically shaped outside surface and a minimum inside diameter at least equal to the maximum diameter of said frusto-conical part and in the second condition said expansion sleeve being deformed in the region of said web so that the inside surface thereof moves inwardly whereby the inside surface in circumferentially spaced locations is in surface contact with the surface of said reduced diameter part and said webs being expandable from the second condition for securing said anchor bolt within a borehole.