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Title: Nonrotating, self-centering anchor assembly for anchoring a bolt in a borehole

Abstract

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 assemblymore » and therewith the threaded end portion of the elongated bolt within the borehole.« less

Inventors:
 [1];  [1]
  1. (Spokane, WA)
Issue Date:
Research Org.:
National Energy Technology Laboratory, Pittsburgh, PA, and Morgantown, WV
OSTI Identifier:
872019
Patent Number(s):
5846041
Assignee:
United States of America as represented by United States (Washington, DC) NETL
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
nonrotating; self-centering; anchor; assembly; anchoring; bolt; borehole; expandable; provided; threaded; portion; elongated; roof; hollow; outer; sleeve; form; plurality; symmetrically; arranged; longitudinal; segmented; wall; portions; exterior; gripping; teeth; inner; expander; corresponding; central; axis; define; cylindrical; section; captured; moveable; axially; relative; inserted; trailing; leading; expands; clamps; thereafter; partial; withdrawal; causes; move; wedging; action; radially; expand; force; engagement; sidewall; secure; therewith; cylindrical section; outer sleeve; wall portion; inner sleeve; central axis; roof bolt; axially relative; anchor assembly; move relative; corresponding plurality; wedging action; hollow outer; radially expand; /411/

Citation Formats

Bevan, John E., and King, Grant W. Nonrotating, self-centering anchor assembly for anchoring a bolt in a borehole. United States: N. p., 1998. Web.
Bevan, John E., & King, Grant W. Nonrotating, self-centering anchor assembly for anchoring a bolt in a borehole. United States.
Bevan, John E., and King, Grant W. Thu . "Nonrotating, self-centering anchor assembly for anchoring a bolt in a borehole". United States. https://www.osti.gov/servlets/purl/872019.
@article{osti_872019,
title = {Nonrotating, self-centering anchor assembly for anchoring a bolt in a borehole},
author = {Bevan, John E. and King, Grant W.},
abstractNote = {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.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1998},
month = {1}
}

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