HIGH-CAPACITY RADIAL FIT COUPLING BOLTS

摘要

A high capacity radial-fit coupling bolt (or “expanding sleeve bolt”) has a pair of tapered sleeves about a shank of a bolt to which can be applied a tensioning load. An extrudable ring, or a compression ring, is interposed between a head nut or head flange at one end of the shank, and one end of an inner sleeve. A tensioning load is applied to the shank, the inner sleeve causing the outer sleeve to expand diametrically. At a preset load limit, the extrudable ring is extruded through at least one bore in a drive piston between the head nut and the extrudable ring, to allow shank to move relative to the inner sleeve until the tensioning load is fully applied. Alternatively, a drive member is provided between the head nut or head flange and the compression ring, and at a preset limit, the compression ring allows the shank to move relative to inner sleeve until the tensioning load is fully applied. The preset limit will typically correspond to the force required to fully expand the outer sleeve.

主权项

1. A high-capacity radial fit coupling bolt assembly, or high-capacity expanding sleeve bolt assembly, to secure at least two components together, the assembly including:
a shank having a substantially cylindrical central portion intermediate first and second end portions; respective inner and outer sleeves surrounding at least a section of the central portion of the shank, the inner and outer sleeves having complimentary respective outer and inner tapered engagement faces; and an extrusion ring interposed between a first end of the inner sleeve and a drive piston at or adjacent the first end portion of the shank, the drive piston having at least one axial bore open to the extrusion ring; so arranged that, as a tensioning load is increasingly applied to the second end portion of the shank, relative axial movement between the inner and outer sleeves will cause the outer sleeve to expand diametrically into engagement with the at least two components up to a preset limit, at which the extrusion ring will at least be partially extruded through the at least one axial bore, thereby allowing the shank to move without displacing the outer sleeve relative to the at least two components.