Expansion stud
AssigneeU.S. Expansion Bolt Company
InventorEdward P. McCarthy
Life of this patent
Estimating the term…
Abstract
An expansion stud for use in a blind bore hole or the like formed in a concrete anchorage or like support, wherein an expansion sleeve is caused to expand radially in perpendicular relation to the longitudinal axis of the expansion stud and to the bore hole wall. The stud is provided at its inner end with a conically tapered wedge tip formation whose smaller end is integral with the main body of the stud. The expansion sleeve is provided with an internal conically tapered bore which corresponds to the conical taper of the wedge tip, such that axial outward movement of the stud relative to the expansion sleeve causes radial expansion thereof perpendicular to the stud axis and the bore hole wall.
Claims8
An expansion stud which is adapted to be inserted into, and to expand in, a bore hole in a concrete anchorage or the like, said expansion stud comprising:
- a. a cylindrical shank,
- b. the upper end of said cylindrical shank being threaded for engagement with a nut,
- c. the lower end of said shank having a wedge tip which is conically tapered throughout its length up to said lower end of said shank, said wedge tip oriented with its smaller end directed upwardly and joined directly to the shank, its larger end directed downwardly away from the shank, and the maximum diameter of said wedge tip being substantially no greater than the diameter of said shank,
- d. an expansion sleeve mounted, when in unexpanded state, on the smaller upper end of said wedge tip,
- e. said expansion sleeve, in unexpanded state, having a conically tapered axial bore the conical angle of which is substantially the same as the conical angle of said wedge tip, and a substantially cylindrical outer configuration having a diameter which corresponds, substantially, to the diameter of the shank,
- f. whereby causing the cylindrical shank and the wedge tip to move upwardly and axially relative to the expansion sleeve causes expansion thereof in opposite radial directions perpendicular to the shank axis,
- g. the length of the wedge tip exceeding the length of the expansion sleeve approximately twice the length of the expansion sleeve,
- h. whereby, when expanded to full capacity, the expansion sleeve remains fully supported on the wedge tip.
Dependencies are inferred from the claim text.