US4984938A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coated washer for an anchor bolt system
Assignee: H&S Machine and Supply Co Inc
•
Filing: 1989-09-28
•
Granted: 1991-01-15
•
Expires: 2009-09-28
Abstract
Abstract The anchor bolt assembly is of the tensionable type used in mine roofs and the like in which the anchor bolt assembly is positioned in a bore hole of a rock formation. The bolt assembly includes an elongated bolt shaft with a head at one end and is threaded on the other end and has a mechanical expansion anchor on the threaded end. A bearing having a central opening is positioned on the bolt to engage a face of the rock formation. A two faced graphite coated washer is positioned on the bolt between the bolt head and the bearing plate. During installation, the washer acts as an anti-friction bearing between the bolt head and the plate to improve the torque to tension relationship.
Inventors
- 👤 Ralph F. Scott, Jr.
- 👤 Frank M. Locotos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:52
CPC Classifications
E; E21; E21D; E21D21/00; E21D21/0093; F; F16; F16B; F16B43/00; F16B43/002; F16B13/00; F16B13/04; F16B13/06; F16B13/063; F16B13/066; F16B13/14; F16B2013/008; F16B31/00; F16B31/02; Y; Y10; Y10S; Y10S411/00; Y10S411/90; Y10S411/901; Y10S411/902; Y10S411/903
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
116 words
In an anchor bolt assembly for insertion into a pre-drilled hole of a rock formation within a mine and comprising an elongated roof bolt having a head at one end external of the hole, a bearing plate having a central opening and positioned on said bolt to engage a face of said rock formation and a two-faced hardened steel washer positioned on said bolt between said bolt head and said bearing plate, the improvement comprising a coating formed of a dry graphite lubricant suspension on both faces of said washer, wherein said anchor bolt assembly being tensioned and the washer acting to reduce friction between said bolt head and said plate to improve the torque-tension relationship.
Claim 2
Dependent Claim
116 words
In an anchor bolt assembly for insertion into a pre-drilled hole of a rock formation within a mine and comprising an elongated roof bolt having a head at one end external of the hole, a bearing plate having a central opening and positioned on said bolt to engage a face of said rock formation and a two-faced hardened steel washer positioned on said bolt between said bolt head and said bearing plate, the improvement comprising a coating formed of a dry graphite lubricant suspension on both faces of said washer, wherein said anchor bolt assembly being tensioned and the washer acting to reduce friction between said bolt head and said plate to improve the torque-tension relationship.
Claim 3
Dependent Claim
20 words
The anchor bolt assembly as defined in claim 1 wherein said graphite coating is at least 0.0005" thick per face.
Claim 4
Dependent Claim
21 words
The anchor bolt assembly as defined in claim 1 wherein said coating comprises a graphite suspension in a resin based system.
Claim 5
Dependent Claim
26 words
The anchor bolt assembly as defined in claim 1 wherein said graphite coating comprises a graphite suspension in a resin base having about 30%-50% suspended solids.
Claim 6
Dependent Claim
26 words
The anchor bolt assembly as defined in claim 4 wherein said graphite coating comprises a graphite suspension in a resin base having about 35%-45% suspended solids.
Claim 7
Dependent Claim
19 words
The anchor bolt assembly as defined in claim 5 wherein said coating is at least 0.0005" thick per face.
Claim 8
Dependent Claim
26 words
The anchor bolt assembly as defined in claim 4 wherein said graphite coating comprises a graphite suspension in a resin base having about 35%-40% suspended solids.
Claim 9
Dependent Claim
26 words
The anchor bolt assembly as defined in claim 4 wherein said graphite coating comprises a graphite suspension in a resin base having about 37.5% suspended solids.
Claim 10
Dependent Claim
146 words
In a method of reinforcing a rock formation in a maine having a pre-drilled bore hole with at least one anchor bolt assembly, said anchor bolt assembly comprising an elongated roof bolt having a head at one end, a bearing plate having a central opening and positioned on said bolt to engage a face of said rock formation and a two-faced hardened steel washer positioned on said bolt between said bolt head and said bearing plate, comprising: A. advancing said roof bolt into the bore hole; and B. rotating said bolt head in one direction until said bearing plate comes into contact with said face of said rock formation and places said bolt in tension; the improvement comprising: reducing the coefficient of friction between said bearing plate, said washer, and said bolt head by coating both faces of said washer with a dry graphite lubricant suspension.
Claim 11
Dependent Claim
146 words
In a method of reinforcing a rock formation in a maine having a pre-drilled bore hole with at least one anchor bolt assembly, said anchor bolt assembly comprising an elongated roof bolt having a head at one end, a bearing plate having a central opening and positioned on said bolt to engage a face of said rock formation and a two-faced hardened steel washer positioned on said bolt between said bolt head and said bearing plate, comprising: A. advancing said roof bolt into the bore hole; and B. rotating said bolt head in one direction until said bearing plate comes into contact with said face of said rock formation and places said bolt in tension; the improvement comprising: reducing the coefficient of friction between said bearing plate, said washer, and said bolt head by coating both faces of said washer with a dry graphite lubricant suspension.
Claim 12
Dependent Claim
22 words
The method of claim 9, further comprising applying said graphite coating in a thickness of at least 0.0005" inches thick per face.
Claim 13
Dependent Claim
17 words
The method of claim 9, wherein said coating comprises a graphite suspension in a resin based system.
Claim 14
Dependent Claim
22 words
The method of claim 9, wherein said graphite coating comprises a graphite suspension in a resin base having about 30%-50% suspended solids.
Claim 15
Dependent Claim
22 words
The method of claim 9, wherein said graphite coating comprises a graphite suspension in a resin base having about 37.5% suspended solids.
Claim 16
Dependent Claim
192 words
In a method of reinforcing a rock formation in a mine having a pre-drilled bore hole with at least one anchor bolt assembly, said anchor bolt assembly comprising an elongated roof bolt having a threaded first end with an expansion anchor carried on said threads, a support mechanism affixed to said bolt shaft at a bottom of said threads, a head at a second end, a bearing plate having a central opening and positioned on said bolt to engage a face of said rock formation and a two-faced hardened steel washer positioned on said bolt between said bolt head and said bearing plate, comprising: A. advancing said roof bolt and expansion member into the bore hole; B. rotating said bolt head in one direction until said bearing plate comes into contact with said face of said rock formation; and C. continuing rotating said bolt head until said expansion anchor causes said support mechanism to fail, whereby placing said bolt in tension; the improvement comprising: reducing the coefficient of friction between said bearing plate, said washer, and said bolt head by coating both faces of said washer with a dry graphite lubricant suspension.
Claim 17
Dependent Claim
192 words
In a method of reinforcing a rock formation in a mine having a pre-drilled bore hole with at least one anchor bolt assembly, said anchor bolt assembly comprising an elongated roof bolt having a threaded first end with an expansion anchor carried on said threads, a support mechanism affixed to said bolt shaft at a bottom of said threads, a head at a second end, a bearing plate having a central opening and positioned on said bolt to engage a face of said rock formation and a two-faced hardened steel washer positioned on said bolt between said bolt head and said bearing plate, comprising: A. advancing said roof bolt and expansion member into the bore hole; B. rotating said bolt head in one direction until said bearing plate comes into contact with said face of said rock formation; and C. continuing rotating said bolt head until said expansion anchor causes said support mechanism to fail, whereby placing said bolt in tension; the improvement comprising: reducing the coefficient of friction between said bearing plate, said washer, and said bolt head by coating both faces of said washer with a dry graphite lubricant suspension.
References Cited (Backward Citations)
US3244625A
Cited
US3375193A
Cited
US3377278A
Cited
US3634129A
Cited
US3914178A
Cited
US4074011A
Cited
US3926818A
Cited
US4097257A
Cited
US3962103A
Cited
US4179529A
Cited
US4206060A
Cited
US4354948A
Cited
US4556344A
Cited
US4538790A
Cited
US4564315A
Cited
US4619559A
Cited
US4746248A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-01-14 | 1994-07-16 | 1995-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-14 | 1998-07-16 | 1999-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-14 | 2002-07-16 | 2003-01-15 | $7700.00 | Window Closed / Lapsed |