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

Patent · Thu Jan 01 04:00:00 EST 1998

OSTI ID:872019

Bevan, John E ^[1]; King, Grant W ^[1]

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1. Spokane, WA

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: National Energy Technology Laboratory, Pittsburgh, PA, and Morgantown, WV
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 5846041
• OSTI ID: 872019
• Country of Publication: United States
• Language: English

Related Subjects

/411/
action
anchor
anchor assembly
anchoring
arranged
assembly
axially
axially relative
axis
bolt
borehole
captured
causes
central
central axis
clamps
corresponding
corresponding plurality
cylindrical
cylindrical section
define
elongated
engagement
expand
expandable
expander
expands
exterior
force
form
gripping
hollow
hollow outer
inner
inner sleeve
inserted
leading
longitudinal
move
move relative
moveable
nonrotating
outer
outer sleeve
partial
plurality
portion
portions
provided
radially
radially expand
relative
roof
roof bolt
section
secure
segmented
self-centering
sidewall
sleeve
symmetrically
teeth
thereafter
therewith
threaded
trailing
wall
wall portion
wedging
wedging action
withdrawal