Patent US4578826A successfully refreshed from Google Patents.
US3945753A
Expired / Lapsed
US
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Drill bit device
Assignee: PORTA-TOOLS Inc
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Filing: 1974-07-29
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Granted: 1976-03-23
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Expires: 1994-07-29
Abstract
Abstract Drill bit construction having a removable lead screw and a drill body with a work face comprised of two planar surfaces which geometrically intersect on a diameter line such that the angle between the two surfaces is approximately 170°. A cut-away segment is formed on each side of the body with each of the segments having a cutting edge in the form of a detachable blade which is also provided with a cutting spur on the outer end. The body itself is detachably removable from the drill shaft or shank. The body is also provided with a removable lead screw or guide point.
Inventors
- 👤 John E. Byers
- 👤 Gary L. Byers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:03
CPC Classifications
B; B27; B27G; B27G15/00; Y; Y10; Y10T; Y10T408/00; Y10T408/89; Y10T408/892; Y10T408/8923; Y10T408/902
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
189 words
A boring tool, comprising: a. a generally circular drill bit body in the nature of a solid, shallow cylinder, said body having a back surface, a side edge surface and a working face, said working face being Occasionally a defined by a pair of opposed work surfaces in which at least flat planar portions thereof extend axially forwardly at an angle from a plane normal to the body axis and radially inwardly such that when extended intersect to define an intersection line passing through and normal to the body axis, b. a pair of angling cut-away segments generally in opposed quadrants of the working face such that a segment extends through said body from the back surface to a working surface, said cut-away segments having cutting edges therein, c. a shaft mounting portion located generally centrally of and extending rearwardly from the back surface of said body and containing means for detachably connecting said body to a shaft, d. centrally located hole in the working face of said body which is provided with a lead screw, and e. securing means for detachably holding said body and lead screw together.
Claim 2
Dependent Claim
189 words
A boring tool, comprising: a. a generally circular drill bit body in the nature of a solid, shallow cylinder, said body having a back surface, a side edge surface and a working face, said working face being Occasionally a defined by a pair of opposed work surfaces in which at least flat planar portions thereof extend axially forwardly at an angle from a plane normal to the body axis and radially inwardly such that when extended intersect to define an intersection line passing through and normal to the body axis, b. a pair of angling cut-away segments generally in opposed quadrants of the working face such that a segment extends through said body from the back surface to a working surface, said cut-away segments having cutting edges therein, c. a shaft mounting portion located generally centrally of and extending rearwardly from the back surface of said body and containing means for detachably connecting said body to a shaft, d. centrally located hole in the working face of said body which is provided with a lead screw, and e. securing means for detachably holding said body and lead screw together.
Claim 3
Dependent Claim
30 words
The drill bit device according to claim 1 and in which said side edge surface angles inwardly from said working face to said back surface at a predetermined small angle.
Claim 4
Dependent Claim
36 words
The drill bit device according to claim 2 and in which each of said cut-away segments is provided with a recessed portion in which is located a detachable and replaceable cutting blade having a cutting edge.
Claim 5
Dependent Claim
52 words
The drill bit device of claim 3 wherein each of said cutting blades generally comprises a portion of its respective work surface to define a cutting edge which is forward of and parallel to said intersection line and which edge is generally at a right angle to the axis of said body.
Claim 6
Dependent Claim
27 words
The drill bit device according to claim 4 and wherein each of said cutting blades is provided with a raised cutting spur at the outer edge thereof.
Claim 7
Dependent Claim
50 words
The drill bit device according to claim 5 and wherein each of said cut-away segments opens forward of its respective cutting blade and cutting edge and angles rearwardly through said body to open on said back surface generally centered with respect to a plane through the axis and intersection line.
Claim 8
Dependent Claim
30 words
The drill bit device of claim 6 and wherein said cut-away segments on said working face extend generally from near the center of said body to said side edge surface.
Claim 9
Dependent Claim
28 words
The drill bit device of claim 7 and wherein said cut-away segments on said back surface extend generally from said shaft mounting portion to said side edge surface.
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) | 1979-03-23 | 1979-09-22 | 1980-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-23 | 1983-09-22 | 1984-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-23 | 1987-09-22 | 1988-03-23 | $7700.00 | Window Closed / Lapsed |