US4190126A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotary abrasive drilling bit
Assignee: Tokiwa Kogyo Co Ltd
•
Filing: 1977-12-20
•
Granted: 1980-02-26
•
Expires: 1997-12-20
Abstract
Abstract A rotary abrasive drilling bit disclosed herein is of a construction wherein teeth are equipped on the fore part of a bit body attached to a rotary drill pipe, each of said teeth is composed of a plurality of chips which are made of cemented tungstencarbide and the matrix thereof which is soft and inferior in abrasion resistance relative to said cutting elements or chips, each chip is shaped like a thin stick and extends along the cutting direction of said bit body, the matrix surrounds said chips, and in the matrix of each tooth the chips are orderly arranged to leave a desired interspace along the direction of radius as well as the direction of circumference of the bit body.
Inventors
- 👤 Ryuichi Kabashima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:15
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/46; E21B10/56; E21B10/567; E21B10/006; E21B10/48; E21B17/00; E21B17/10; E21B17/1092
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
202 words
A rotary abrasive drilling bit comprising a bit body attached to a rotary drill pipe and a plurality of teeth equipped on the fore part of said bit body, wherein each of said teeth is composed of a plurality of tungsten carbide thin sticklike cutting elements and a matrix that is softer than and inferior in abrasion resistance to said elements, all said sticklike tungsten carbide elements extending along the cutting direction of said bit body and orderly arranged in each tooth with a desired space therebetween radially as well as circumferentially of the bit body with the ends located in a zig-zag path transverse to said cutting direction, said matrix surrounding the tungsten carbide thin sticklike elements and maintaining them in the aforesaid arrangement, and the cutting face of said tooth being composed of a compound surface consisting of the end faces of the tungsten carbide thin sticklike elements and the surface of the matrix, whereby when the edges of the tungsten carbide thin sticklike elements are worn down and shortened with the progress of drilling work the surface of the matrix is also worn down to the same extent in concert therewith to maintain the teeth suitable for drilling purposes.
Claim 2
Dependent Claim
202 words
A rotary abrasive drilling bit comprising a bit body attached to a rotary drill pipe and a plurality of teeth equipped on the fore part of said bit body, wherein each of said teeth is composed of a plurality of tungsten carbide thin sticklike cutting elements and a matrix that is softer than and inferior in abrasion resistance to said elements, all said sticklike tungsten carbide elements extending along the cutting direction of said bit body and orderly arranged in each tooth with a desired space therebetween radially as well as circumferentially of the bit body with the ends located in a zig-zag path transverse to said cutting direction, said matrix surrounding the tungsten carbide thin sticklike elements and maintaining them in the aforesaid arrangement, and the cutting face of said tooth being composed of a compound surface consisting of the end faces of the tungsten carbide thin sticklike elements and the surface of the matrix, whereby when the edges of the tungsten carbide thin sticklike elements are worn down and shortened with the progress of drilling work the surface of the matrix is also worn down to the same extent in concert therewith to maintain the teeth suitable for drilling purposes.
Claim 3
Dependent Claim
69 words
A rotary abrasive drilling bit according to claim 1 wherein the shape of the cross section of each tungsten carbide thin sticklike cutting element is substantially semicircular and the linear portion of said semicircular shape is disposed at the rear in relation to the direction of rotation of said bit body to thereby minimize the resistance applied onto the cutting face at exposed ends of the tungsten carbide elements.
Claim 4
Dependent Claim
28 words
A rotary abrasive drilling bit according to claim 1 wherein the major cross sectional dimension of each tungsten carbide thin sticklike cutting element is less than 5 millimeters.
Claim 5
Dependent Claim
33 words
A rotary abrasive drilling bit according to claim 1 wherein the major cross sectional dimension of each tungsten carbide thin sticklike cutting element is in the range of from 1 to 3 millimeters.
Claim 6
Dependent Claim
22 words
A rotary abrasive drilling bit according to claim 1 wherein said matrix consists of an alloy including nickel, copper, silver, or zinc.
References Cited (Backward Citations)
IT679193A
Cited
US2147843A
Cited
US2234273A
Cited
US3106973A
Cited
US3546150A
Cited
DE2035261A1
Cited
US3726351A
Cited
US4042347A
Cited
US3999962A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-02-25 | 1983-08-27 | 1984-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-25 | 1987-08-27 | 1988-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-25 | 1991-08-27 | 1992-02-26 | $7700.00 | Window Closed / Lapsed |