US4557609A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotary drill bit
Assignee: Santrade Ltd
•
Filing: 1981-03-24
•
Granted: 1985-12-10
•
Expires: 2001-03-24
Abstract
Abstract A sealed rotary drill bit comprising at least one rotatably carried roller cutter (13) and provided with a seal between the cutter and a mounting head (22) for preventing lubricating medium from being discharged from the bearing (14, 15, 16, 17, 18) and impurities from entering the bearing. For purposes of decreasing the friction the seal (22) is provided with a low friction material on a portion of the seal which engages the head to promote rotation between the seal and the head. The portion of the seal which engages the roller cutter has a material of higher frictional coefficient to resist relative rotation between the seal and the roller cutter (25).
Inventors
- 👤 Rolf R. Moren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:00
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/08; E21B10/22; E21B10/25; F; F16; F16J; F16J15/00; F16J15/16; F16J15/32; F16J15/3284; Y; Y10; Y10S; Y10S277/00; Y10S277/91; Y10S277/935; Y10S277/944; Y10S277/945; Y10S277/946
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
189 words
A rotary drill bit comprising a head, at least one roller cutter, said roller cutter being rotatably carried by said head upon bearing means, an annular resilient sealing means disposed in a gap between said head and roller cutter for sealing said bearing means, said sealing means having a sealing surface for sealingly engaging said head and roller cutter, the improvement wherein a first portion of said sealing surface is formed of a first material attached to the sealing means and positioned at a location for engaging said head and avoiding any appreciable engagement with said roller cutter, said first material being of a thickness thin enough to allow deformation thereof caused by axial and/or wobbling movements of the roller cutter relative to the head, a second portion of said sealing surface frictionally engaging said roller cutter and being formed of a resilient second material having a coefficient of friction higher than that of said first material so that the frictional resistance to relative rotation between said sealing means and said roller cutter is greater than the frictional resistance to relative rotation between said sealing means and said head.
Claim 2
Dependent Claim
189 words
A rotary drill bit comprising a head, at least one roller cutter, said roller cutter being rotatably carried by said head upon bearing means, an annular resilient sealing means disposed in a gap between said head and roller cutter for sealing said bearing means, said sealing means having a sealing surface for sealingly engaging said head and roller cutter, the improvement wherein a first portion of said sealing surface is formed of a first material attached to the sealing means and positioned at a location for engaging said head and avoiding any appreciable engagement with said roller cutter, said first material being of a thickness thin enough to allow deformation thereof caused by axial and/or wobbling movements of the roller cutter relative to the head, a second portion of said sealing surface frictionally engaging said roller cutter and being formed of a resilient second material having a coefficient of friction higher than that of said first material so that the frictional resistance to relative rotation between said sealing means and said roller cutter is greater than the frictional resistance to relative rotation between said sealing means and said head.
Claim 3
Dependent Claim
40 words
A rotary drill bit according to claim 1, wherein said head includes first and second angularly related surfaces, said first portion of said sealing surface is positioned so as to rest against said first and second surfaces of the head.
Claim 4
Dependent Claim
23 words
A rotary drill bit according to claim 1, wherein the sealing means comprises an O-ring having a substantially circular cross-section upon being dismounted.
Claim 5
Dependent Claim
14 words
A rotary drill bit according to claim 1, wherein said first material is polytetrafluorethylene.
References Cited (Backward Citations)
US2717025A
Cited
US2868575A
Cited
US3097893A
Cited
US3322433A
Cited
US3397928A
Cited
US3467448A
Cited
US3604523A
Cited
US3761145A
Cited
US3848880A
Cited
US3866987A
Cited
DE2503807A1
Cited
US4168868A
Cited
US4167219A
Cited
US4200343A
Cited
US4306727A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-09 | 1989-06-10 | 1989-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-09 | 1993-06-10 | 1993-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-09 | 1997-06-10 | 1997-12-10 | $7700.00 | Window Closed / Lapsed |