Patent US5399158A successfully refreshed from Google Patents.
US3599736A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotary drill bit
Assignee: American Coldset Corp
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Filing: 1970-05-18
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Granted: 1971-08-17
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Expires: 1990-05-18
Abstract
Abstract A rotary bit for drilling earth formations of the type having an elongated cylindrical body and an enlarged head having wearresistant abrasive particles embedded therein to form a cutting surface. An improved cutting surface comprises a concave face, a convex annular tapered crown faired into the face at its inner limit and a cylindrical skirt extending a substantial axial distance from the outer limit of the crown. Wear-resistant abrasive particles are embedded in substantially parallel rows upon the surfaces of an odd number of cutting lands substantially equally spaced about the skirt and crown and terminating assymmetrically in the face region. Drilling fluid is conveyed by an inner passageway through the body of the bit to a Y-shaped outlet on the face and thence uniformly to the cutting surfaces through primary waterways between the lands and secondary waterways between the rows of wear-resistant particles.
Inventors
- 👤 Charles T Thompson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:54
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/46
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
361 words
A rotary bit for drilling earth formations, the bit being of the type having an elongated body portion with a threaded shank at one end thereof for coupling to a drill string, an enlarged drilling head on the other end of the body portion, the drilling head having cutting particles imbedded in its outer surface for cutting the earth formations, and an interior passageway extending through the body from an inlet at the shank end to an outlet at the cutting surface of the drilling head for supplying drilling liquid to cool the cutting particles and flush away the cut formations, wherein the improvement in the drilling head comprises: a. a multiplicity of lands for supporting the cutting particles adjacent the surface thereof, the multiplicity of lands forming grooves therebetween and being spaced about the body portion, the lands extending from a location intermediate the ends of the body portion to form successively, i. an outer cylindrical fluted skirt section coaxial with and of larger diameter than the body portion, ii. an intermediate convex crown section which tapers smoothly inwardly from the skirt section and away from the one end of the body portion in the form of a body of revolution generated by a curve which is a portion of a substantially conic section, the crown section terminating along a circle coaxial with and at a distance from the axis of the body portion, the portion of the crown section adjacent the termination thereof forming the extreme free end portion of the drilling head, and iii. an inner concave face section concentric about the axis of the body portion and fairing smoothly into the crown section along the termination thereof; each of said lands having substantially constant width through the skirt and tapered crown sections, the grooves between adjacent lands forming primary waterways which extend substantially parallel in the skirt section and gradually narrow in width in the tapered crown section, the lands terminating in tapered asymmetrical relation within the concave face section and the grooves therebetween extending the primary waterways to connect each of the grooves of the skirt and tapered crown sections to the outlet for drilling liquid.
Claim 2
Dependent Claim
361 words
A rotary bit for drilling earth formations, the bit being of the type having an elongated body portion with a threaded shank at one end thereof for coupling to a drill string, an enlarged drilling head on the other end of the body portion, the drilling head having cutting particles imbedded in its outer surface for cutting the earth formations, and an interior passageway extending through the body from an inlet at the shank end to an outlet at the cutting surface of the drilling head for supplying drilling liquid to cool the cutting particles and flush away the cut formations, wherein the improvement in the drilling head comprises: a. a multiplicity of lands for supporting the cutting particles adjacent the surface thereof, the multiplicity of lands forming grooves therebetween and being spaced about the body portion, the lands extending from a location intermediate the ends of the body portion to form successively, i. an outer cylindrical fluted skirt section coaxial with and of larger diameter than the body portion, ii. an intermediate convex crown section which tapers smoothly inwardly from the skirt section and away from the one end of the body portion in the form of a body of revolution generated by a curve which is a portion of a substantially conic section, the crown section terminating along a circle coaxial with and at a distance from the axis of the body portion, the portion of the crown section adjacent the termination thereof forming the extreme free end portion of the drilling head, and iii. an inner concave face section concentric about the axis of the body portion and fairing smoothly into the crown section along the termination thereof; each of said lands having substantially constant width through the skirt and tapered crown sections, the grooves between adjacent lands forming primary waterways which extend substantially parallel in the skirt section and gradually narrow in width in the tapered crown section, the lands terminating in tapered asymmetrical relation within the concave face section and the grooves therebetween extending the primary waterways to connect each of the grooves of the skirt and tapered crown sections to the outlet for drilling liquid.
Claim 3
Dependent Claim
62 words
A rotary bit in accordance with claim 1 in which the cutting particles are disposed in substantially parallel rows extending along the length of the lands, the radial positioning of the cutting particles being staggered in the radial direction with respect to one another to enable all portions of the bore hole be subjected to the cutting action of the cutting particles.
Claim 4
Dependent Claim
39 words
A rotary bit in accordance with claim 1 in which the lands of the cylindrical skirt section are provided with wear-resistant particles mounted substantially flush with the surface thereof for preventing wear of the lands of the skirt section.
Claim 5
Dependent Claim
127 words
A rotary bit in accordance with claim 1 in which the cross section of the outer cylindrical fluted skirt section extending transverse with respect to the axis of the body portion comprises the surface of each of the multiplicity of lands being disposed upon and spaced apart along a common circle and the relieved surface of each of the grooves forming the primary waterways extending inwardly from the common circle between each of the adjacEnt lands, whereby the disposing of the lands along the common circle improves the stability of the drill and the grooves along the common circle provide a flow passage with respect to the wall of the bore hole whenever the bit is moved toward or away from the bottom of the bore hole.
Claim 6
Dependent Claim
48 words
A rotary bit in accordance with claim 1 wherein the cylindrical skirt section has an axial length approximately equal to the length of the intermediate convex crown section, whereby the tapered crown and cylindrical skirt serve to respectively pilot and stabilize the bit in the desired drilling direction.
Claim 7
Dependent Claim
33 words
A rotary bit in accordance with claim 1 wherein the inner concave face section is substantial in the form of an inverted cone having an included angle in the vicinity of approximately 80*.
Claim 8
Dependent Claim
43 words
A rotary bit in accordance with claim 1 in which the portion of each of the multiplicity of lands forming the inner concave face section extend in an approximately radial direction with respect to the central axis of the inner concave face section.
Claim 9
Dependent Claim
41 words
A rotary bit in accordance with claim 1 in which the improvement further comprises cutting particles of diamond material mounted in the surface of the multiplicity of the lands in the inter concave face section and the intermediate convex crown section.
Claim 10
Dependent Claim
37 words
A rotary bit in accordance with claim 8 wherein the circular termination of the crown section has a radius in the vicinity of about 70 percent of the outer radius of the skirt section of the bit.
Claim 11
Dependent Claim
39 words
A rotary bit in accordance with claim 1 in which each of said lands contain additional grooves forming secondary waterways extending along the surface thereof substantially parallel to the grooves adjacent to the land and forming the primary waterways.
Claim 12
Dependent Claim
31 words
A rotary bit in accordance with claim 10 in which the cutting particles are disposed in rows extending adjacent to and substantially parallel to the additional grooves forming the secondary waterways.
Claim 13
Dependent Claim
41 words
A rotary bit in accordance with claim 1 in which the number of the multiplicity of lands is an odd number to prevent lands at opposite sides of the intermediate convex crown section from being disposed along a common diametral line.
Claim 14
Dependent Claim
29 words
A rotary bit in accordance with claim 12 in which the odd number of the multiplicity of lands is in the vicinity of the odd number of approximately 21.
Claim 15
Dependent Claim
54 words
A rotary bit in accordance with claim 1 in which the outlet of the interior passageway for supplying drilling liquid extends across a portion of the lands forming the inner concave face section and a portion of the grooves adjacent thereto, whereby drilling fluid is distributed to the cutting particles supported on the lands.
Claim 16
Dependent Claim
57 words
A rotary bit in accordance to claim 14 in which the outlet of the interior passageway for supplying a drilling liquid is offset with respect to axis of the body portion, whereby the portion of the inner concave face section adjacent the axis of the body portion is avoidable to applying cutting particles to the bore hole.
Claim 17
Dependent Claim
52 words
A rotary bit in accordance with claim 15 in which the outlet of the interior passageway is substantially in the form of a letter Y with the portion of the outlet corresponding to the notch of the letter Y being disposed offset from but adjacent to the axis of the body portion.
References Cited (Backward Citations)
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Cited
US2493178A
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US2838284A
Cited
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Cited
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Cited
US3112803A
Cited
US3318400A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-16 | 1975-02-15 | 1975-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-16 | 1979-02-15 | 1979-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-16 | 1983-02-15 | 1983-08-17 | $7700.00 | Window Closed / Lapsed |