US3739864A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure equalizing system for rock bits
Assignee: Dresser Industries Inc
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Filing: 1971-08-12
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Granted: 1973-06-19
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Expires: 1991-08-12
Abstract
Abstract A lubricant reservoir is positioned in each of the three arms of a three cone rotary rock bit to provide lubricant to the bearings located between the cone cutters and the bearing shafts upon which they rotate. A seal is positioned between the cone cutters and the bearing shafts to retain lubricant in the bearing area and to prevent borehole fluids and debris from entering the bearing area. A flexible diaphragm positioned in the lubricant reservoir divides the reservoir into a lubricant portion and a pressure equalizing portion. A vent passage extends from the pressure equalizing portion of the lubricant reservoir to an area on the exterior surface of the bit wherein the borehole fluid pressure on the bit is substantially the same as the borehole fluid pressure on the seal.
Inventors
- 👤 G Cason
- 👤 J Simmons
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:23
CPC Classifications
F; F16; F16C; F16C33/00; F16C33/30; F16C33/66; F16C33/6603; F16C33/6607; E; E21; E21B; E21B10/00; E21B10/08; E21B10/22; E21B10/24; F16C33/6622; F16C2352/00
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
230 words
A rotary rock bit for use in a drilling operation wherein fluid is circulated through a well bore, comprising: a bit body; at least one arm extending from said bit body; a cone cutter rotatably mounted upon said arm; bearing means between said cone cutter and said arm for promoting rotation of said cone cutter; a lubricant reservoir in said arm; a lubricant passageway through said arm whereby lubricant from said lubricant reservoir may be transmitted to said bearing means; a seal positioned between said cone cutter and said arm for retaining lubricant proximate said bearing means and for preventing fluid in the well bore from contacting said bearing means; pressure equalizing means positioned in said lubricant reservoir for equalizing the lubricant pressure and the pressure of fluid in the well bore, said pressure equalizing means dividing said lubricant reservoir into a lubricant portion and pressure equalizing portion; and a vent passageway exTending from said pressure equalizing portion of said lubricant reservoir to an area on the exterior surface of said arm wherein the hydrostatic pressure of fluid in the well bore is essentially the same as it is at the seal throughout the drilling operation, said area on the exterior surface of said arm being an area where the fluid velocity during raising and lowering of the bit is essentially the same as the fluid velocity at the seal.
Claim 2
Dependent Claim
230 words
A rotary rock bit for use in a drilling operation wherein fluid is circulated through a well bore, comprising: a bit body; at least one arm extending from said bit body; a cone cutter rotatably mounted upon said arm; bearing means between said cone cutter and said arm for promoting rotation of said cone cutter; a lubricant reservoir in said arm; a lubricant passageway through said arm whereby lubricant from said lubricant reservoir may be transmitted to said bearing means; a seal positioned between said cone cutter and said arm for retaining lubricant proximate said bearing means and for preventing fluid in the well bore from contacting said bearing means; pressure equalizing means positioned in said lubricant reservoir for equalizing the lubricant pressure and the pressure of fluid in the well bore, said pressure equalizing means dividing said lubricant reservoir into a lubricant portion and pressure equalizing portion; and a vent passageway exTending from said pressure equalizing portion of said lubricant reservoir to an area on the exterior surface of said arm wherein the hydrostatic pressure of fluid in the well bore is essentially the same as it is at the seal throughout the drilling operation, said area on the exterior surface of said arm being an area where the fluid velocity during raising and lowering of the bit is essentially the same as the fluid velocity at the seal.
Claim 3
Dependent Claim
21 words
The bit of claim 1 wherein said area on the exterior surface of said arm is located below said lubricant reservoir.
Claim 4
Dependent Claim
15 words
The bit of claim 1 wherein said vent passageway extends downward from said lubricant reservoir.
Claim 5
Dependent Claim
19 words
The bit of claim 1 wherein said area on the exterior surface of said arm is proximate said seal.
Claim 6
Dependent Claim
28 words
The bit of claim 1 wherein said area on the exterior surface of said arm is located on the trailing side of the arm during the drilling operation.
Claim 7
Dependent Claim
15 words
The bit of claim 1 wherein said bearing means includes at least one friction bearing.
Claim 8
Dependent Claim
15 words
The bit of claim 1 wherein said bearing means includes a series of roller bearings.
Claim 9
Dependent Claim
15 words
The bit of claim 1 wherein said bearing means includes a series of ball bearings.
Claim 10
Dependent Claim
14 words
The bit of claim 1 wherein said pressure equalizing means is a flexible diaphragm.
Claim 11
Dependent Claim
32 words
The bit of claim 1 wherein said pressure equalizing means is an element positioned in said lubricant reservoir that transmits pressure information from the fluid in the well bore to the lubricant.
Claim 12
Dependent Claim
214 words
A drill bit for use in a drilling operation wherein fluid is circulated through a well bore, comprising: a bit body; at least one arm extending from said bit body, said arm terminating in a bearing shaft; a cone cutter rotatably mounted upon said bearing shaft; bearing means supporting said cone cutter for promoting rotation of said cone cutter upon said bearing shaft; a seal positioned between said cone cutter and said bearing shaft; a lubricant reservoir positioned in said arm; a passageway through said arm and said bearing shaft wherein lubricant from said lubricant reservoir may be transmitted to the area between the cone cutter and the bearing shaft; a flexible diaphragm positioned in said lubricant reservoir and dividing said lubricant reservoir into a lubricant portion and a pressure equalizing portion; and a vent passageway extending from said pressure equalizing portion of said lubricant reservoir to an area on the exterior surface of said arm wherein the hydrostatic pressure of fluid in the well bore is essentially the same as it is at the seal throughout the drilling operation, said area on the exterior surface of said arm being an area where the fluid velocity during raising and lowering of the bit is essentially the same as the fluid velocity at the seal.
Claim 13
Dependent Claim
214 words
A drill bit for use in a drilling operation wherein fluid is circulated through a well bore, comprising: a bit body; at least one arm extending from said bit body, said arm terminating in a bearing shaft; a cone cutter rotatably mounted upon said bearing shaft; bearing means supporting said cone cutter for promoting rotation of said cone cutter upon said bearing shaft; a seal positioned between said cone cutter and said bearing shaft; a lubricant reservoir positioned in said arm; a passageway through said arm and said bearing shaft wherein lubricant from said lubricant reservoir may be transmitted to the area between the cone cutter and the bearing shaft; a flexible diaphragm positioned in said lubricant reservoir and dividing said lubricant reservoir into a lubricant portion and a pressure equalizing portion; and a vent passageway extending from said pressure equalizing portion of said lubricant reservoir to an area on the exterior surface of said arm wherein the hydrostatic pressure of fluid in the well bore is essentially the same as it is at the seal throughout the drilling operation, said area on the exterior surface of said arm being an area where the fluid velocity during raising and lowering of the bit is essentially the same as the fluid velocity at the seal.
Claim 14
Dependent Claim
21 words
The bit of claim 11 wherein said area on the exterior surface of said arm is located below said lubricant reservoir.
Claim 15
Dependent Claim
15 words
The bit of claim 12 wherein said vent passageway extends downward from said lubricant reservoir.
Claim 16
Dependent Claim
19 words
The bit of claim 13 wherein said area on the exterior surface of said arm is proximate said seal.
Claim 17
Dependent Claim
28 words
The bit of claim 14 wherein said area on the exterior surface of said arm is located on the trailing side of the arm during the drilling operation.
Claim 18
Dependent Claim
15 words
The bit of claim 15 wherein said bearing means includes at least one friction bearing.
Claim 19
Dependent Claim
15 words
The bit of claim 15 wherein said bearing means includes a series of roller bearings.
Claim 20
Dependent Claim
15 words
The bit of claim 15 wherein said bearing means includes a series of ball bearings.
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) | 1976-06-18 | 1976-12-18 | 1977-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-18 | 1980-12-18 | 1981-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-18 | 1984-12-18 | 1985-06-19 | $7700.00 | Window Closed / Lapsed |