Patent US3908386A successfully refreshed from Google Patents.
US3908386A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rock bolt for remote installation
Assignee: WILLIAMS FORM ENGINEERING Corp A MI CORP
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Filing: 1972-04-25
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Granted: 1975-09-30
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Expires: 1992-04-25
Abstract
Abstract A rock bolt having an anchor device set by rotation of the bolt rod, and incorporating means for inhibiting back-rotation of the bolt rod out of the anchor device as reverse torque is applied in disengaging a threaded coupling to disconnect the bolt rod from an actuating rod operated from a remote position.
Inventors
- 👤 Chester I Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:45
CPC Classifications
E; E21; E21D; E21D21/00; E21D21/008
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
159 words
A method of setting a rotatively-set rock bolt in a hole in a ground formation from a remote position, said method comprising: inserting a rock bolt assembly in said hold, said assembly including a bolt rod threaded at the opposite ends thereof, and an anchor device including a cone member in threaded engagement with one of said bolt rod ends, an expansible shell member at least partially surrounding said cone member, and means limiting the axial movement of said shell with respect to said bolt rod; rotating said bolt rod with an extended torque rod having a coupling in threaded engagement with the other of said bolt rod ends, said rotating continuing to the extent of setting said anchor device; and back-rotating said torque rod to disconnect said coupling, said back-rotating being accompanied by limiting the back-rotation of said bolt rod with respect to said cone member by interengaging said cone member and means secured to said bolt rod.
Claim 2
Independent Claim
159 words
A method of setting a rotatively-set rock bolt in a hole in a ground formation from a remote position, said method comprising: inserting a rock bolt assembly in said hold, said assembly including a bolt rod threaded at the opposite ends thereof, and an anchor device including a cone member in threaded engagement with one of said bolt rod ends, an expansible shell member at least partially surrounding said cone member, and means limiting the axial movement of said shell with respect to said bolt rod; rotating said bolt rod with an extended torque rod having a coupling in threaded engagement with the other of said bolt rod ends, said rotating continuing to the extent of setting said anchor device; and back-rotating said torque rod to disconnect said coupling, said back-rotating being accompanied by limiting the back-rotation of said bolt rod with respect to said cone member by interengaging said cone member and means secured to said bolt rod.
Claim 3
Dependent Claim
30 words
A method as defined in claim 1, wherein said torque rod is connected with said coupling to said bolt rod prior to inserting said rock bolt assembly in said hole.
Claim 4
Dependent Claim
33 words
A method as defined in claim 1, wherein said limiting of back rotation is performed by engaging an end of said cone member with means axially fixed with respect to said bolt rod.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |