US3923348A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Friction bearing
Assignee: Camco Drilling Group Ltd
•
Filing: 1974-03-13
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Granted: 1975-12-02
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Expires: 1994-03-13
Abstract
Abstract A friction bearing, particularly useful in drill bits, including a bushing having a borided wear surface, and a method of making the same.
Inventors
- 👤 James A Peck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 00:11
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/08; E21B10/22; F; F16; F16C; F16C21/00; F16C33/00; F16C33/02; F16C33/04; F16C33/06; F16C33/12; F16C33/122; F16C2204/00; F16C2204/60; F16C2352/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
17 words
A friction bearing having relatively rotatable members including: a metallic bushing having a borided inner wear surface.
Claim 2
Dependent Claim
17 words
A friction bearing having relatively rotatable members including: a metallic bushing having a borided inner wear surface.
Claim 3
Dependent Claim
28 words
A friction bearing according to claim 1 wherein the bushing is pressed into one of said relatively rotatable members so that the bushing is maintained in hoop compression.
Claim 4
Dependent Claim
19 words
A friction bearing according to claim 1 wherein a carbon diffusion layer underlies the said borided inner wear surface.
Claim 5
Dependent Claim
18 words
A friction bearing according to claim 3 wherein a non-diffused core layer underlies the said carbon diffusion layer.
Claim 6
Dependent Claim
50 words
A friction bearing for a drill bit roller cutter bore comprising: a metallic bushing pressed into said bore, the inner diameter surface of the bushing comprising a boron diffusion layer, a carbon diffusion layer underlying said boron diffusion layer, and a non-diffuseD core layer underlying the said carbon diffusion layer.
Claim 7
Dependent Claim
50 words
A friction bearing for a drill bit roller cutter bore comprising: a metallic bushing pressed into said bore, the inner diameter surface of the bushing comprising a boron diffusion layer, a carbon diffusion layer underlying said boron diffusion layer, and a non-diffuseD core layer underlying the said carbon diffusion layer.
References Cited (Backward Citations)
US3721307A
Cited
US3823030A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-01 | 1979-06-02 | 1979-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-01 | 1983-06-02 | 1983-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-01 | 1987-06-02 | 1987-12-02 | $7700.00 | Window Closed / Lapsed |