Nonrotating, self-centering anchor assembly for anchoring a bolt in a borehole
An expandable anchor assembly is provided for anchoring the threaded end portion of an elongated roof bolt in a borehole. The anchoring assembly includes a hollow outer sleeve in the form of a plurality of symmetrically arranged, longitudinal segmented wall portions with exterior gripping teeth and an inner expander sleeve in the form of a corresponding plurality of longitudinal wall portions symmetrically arranged about a central axis to define an inner threaded cylindrical section. The inner sleeve is captured within and moveable axially relative to the outer sleeve. As the threaded end portion of the elongated bolt is inserted into the inner threaded cylindrical section of the inner sleeve from the trailing end to the leading end thereof, the inner sleeve expands over and clamps around the threaded end portion of the elongated bolt. Thereafter, partial withdrawal of the elongated bolt from the borehole causes the inner sleeve to axially move relative to the outer sleeve from the leading end toward the trailing end of the outer sleeve in a wedging action to cause the outer sleeve to radially expand and force engagement of the gripping teeth against the sidewall of the borehole to thereby secure the expandable anchor assembly and therewith the threaded end portion of the elongated bolt within the borehole.
- Research Organization:
- US Bureau of Mines (US)
- Sponsoring Organization:
- US Department of Energy (US)
- Assignee:
- DOEGC; EDB-00:057967
- Patent Number(s):
- PATENTS-US-A8891069
- Application Number:
- 8-891,069; TRN: AH200022%%58
- OSTI ID:
- 756761
- Resource Relation:
- Patent File Date: 1997 Jul 10; Other Information: PBD: 1 Dec 1997
- Country of Publication:
- United States
- Language:
- English
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Nonrotating, self-centering anchor assembly for anchoring a bolt in a borehole
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