Patent US3664344A successfully refreshed from Google Patents.
US3866987A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drill bit with laminated friction bearing
Assignee: Smith International Inc
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Filing: 1974-01-14
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Granted: 1975-02-18
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Expires: 1994-01-14
Abstract
Abstract A drill bit bearing assembly having a rotary cutter on a bit leg journal located between a conventional bearing assembly and a rotary cutter seal characterized by two or more concentric relatively wide flat rings between concentric bearing surfaces in the rotary cone cutter and on the leg journal, adjacent ring surfaces and bearing surfaces being in rotary frictional contact and said adjacent surfaces having different coefficients of friction, the rings being of a width such as to substantially fill the space between the ball bearing assembly and the seal, and said rings desirably having openings therethrough between their inner and outer circumferential surfaces, the openings being filled with a dry lubricant, and the openings in adjacent ring surfaces being staggered.
Inventors
- 👤 Lloyd L Garner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:25
CPC Classifications
F; F16; F16C; F16C33/00; F16C33/02; F16C33/04; F16C33/26; E; E21; E21B; E21B10/00; E21B10/08; E21B10/22; F16C21/00; F16C2352/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
86 words
A bearing assembly for a drill bit having a leg journal and a rotary cutter thereon, the leg journal and cutter having concentric opposed surfaces of revolution comprising bearing surfaces, wherein the improvement comprises: at least a pair of concentric friction bearing rings, one ring comprising an inner ring in rotary sliding contact with the leg journal bearing surface, an outer ring in rotary sliding contact with the rotary cutter bearing surface, and said concentric rings being in frictional engagement and rotatable relative to each other.
Claim 2
Dependent Claim
86 words
A bearing assembly for a drill bit having a leg journal and a rotary cutter thereon, the leg journal and cutter having concentric opposed surfaces of revolution comprising bearing surfaces, wherein the improvement comprises: at least a pair of concentric friction bearing rings, one ring comprising an inner ring in rotary sliding contact with the leg journal bearing surface, an outer ring in rotary sliding contact with the rotary cutter bearing surface, and said concentric rings being in frictional engagement and rotatable relative to each other.
Claim 3
Dependent Claim
16 words
The structure in claim 1, and said rings having axial widths greater than their radial thicknesses.
Claim 4
Dependent Claim
22 words
The structure in claim 1, and at least one of said rings and an adjacent bearing surface having different coefficients of friction.
Claim 5
Dependent Claim
21 words
The structure in claim 1, and each of said rings having a different coefficient of friction from the ring adjacent thereto.
Claim 6
Dependent Claim
24 words
The structure in claim 1, and said rings having openings therethrough from one friction surface to the other, and solid lubricant in the openings.
Claim 7
Dependent Claim
20 words
The structure in claim 5, and the openings in one ring being staggered relative to those in an adjacent ring.
Claim 8
Dependent Claim
82 words
The structure in claim 1, and said rotary cutter having an open end, said leg journal and said cutter having a ball bearing assembly between them inwardly from the open end of the rotary cutter, a seal between the rotary cutter and the leg journal adjacent the open end of the rotary cutter and axially spaced from the ball bearing assembly, and said friction bearing rings being located and occupying most of the space between the ball bearing assembly and the seal.
Claim 9
Dependent Claim
35 words
The structure in claim 1, and there being an outer friction bearing ring, an inner ring and an intermediate ring, the intermediate ring having a different coefficient of friction than the outer and inner rings.
Claim 10
Dependent Claim
32 words
The structure in claim 8, and the outer and inner rings each having a different coefficient of friction than that of the bearing surfAce of its respective rotary cutter and leg journal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-17 | 1978-08-19 | 1979-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-17 | 1982-08-19 | 1983-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-17 | 1986-08-19 | 1987-02-18 | $7700.00 | Window Closed / Lapsed |