Patent US4143723A successfully refreshed from Google Patents.
US4143723A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Carbide tipped drill bit for boring holes in concrete and steel
Assignee: Individual
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Filing: 1977-10-04
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Granted: 1979-03-13
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Expires: 1997-10-04
Abstract
Abstract A drill bit having a carbide tip brazed in the drill bit shank is disclosed for use in forming cylindrical holes in both concrete and steel by rotation about a central axis. The carbide tip has two side surfaces on opposite sides of said central axis. The top surfaces are connected by a substantially V-shaped notch which extends between the side surfaces and has its vertex off-center of the central axis to more effectively cut both concrete and steel.
Inventors
- 👤 Norman H. Schmotzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:09
CPC Classifications
B; B23; B23B; B23B51/00; B23B51/06; B23B51/02; B23B2222/00; B23B2222/28; B23B2240/00; B23B2240/08; B23B2251/00; B23B2251/18; B23B2251/46; B23B2251/50; Y; Y10; Y10T; Y10T408/00; Y10T408/78; Y10T408/89; Y10T408/909; Y10T408/9095; Y10T408/9097
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
115 words
A drill for forming cylindrical holes in both concrete and steel, said drill having a bit containing a carbide tip with first and second flat surfaces on opposite sides of the central axis of said drill and having a front and back face extending parallel to said central axis, said front and back faces intersecting with said first and second flat surfaces respectively to form cutting edges wherein the improvement comprises a notch extending between said first and second flat surfaces and said front and back faces, said notch defining sidewalls and having cutting edges formed by the intersection of said sidewalls and said front and back faces to effectively cut said concrete and steel.
Claim 2
Dependent Claim
115 words
A drill for forming cylindrical holes in both concrete and steel, said drill having a bit containing a carbide tip with first and second flat surfaces on opposite sides of the central axis of said drill and having a front and back face extending parallel to said central axis, said front and back faces intersecting with said first and second flat surfaces respectively to form cutting edges wherein the improvement comprises a notch extending between said first and second flat surfaces and said front and back faces, said notch defining sidewalls and having cutting edges formed by the intersection of said sidewalls and said front and back faces to effectively cut said concrete and steel.
Claim 3
Dependent Claim
14 words
A drill as set forth in claim 1 wherein said notch is substantially V-shaped.
Claim 4
Dependent Claim
39 words
A drill as set forth in claim 1 wherein said notch is off-center of said central axis to enable said cutting edges formed by said front and back faces and said sidewalls to more effectively cut concrete and steel.
Claim 5
Dependent Claim
36 words
A drill as set forth in claim 1 further comprising edge surfaces adjacent said first and second flat surfaces, said edge surfaces extending at an angle of approximately 45 degrees with respect to said central axis.
Claim 6
Dependent Claim
24 words
A drill as set forth in claim 4 wherein a cutting edge is formed at the intersection of said edge surfaces and said faces.
Claim 7
Dependent Claim
28 words
A drill as set forth in claim 1 wherein the surface area of said first flat surface is greater than the surface area of said second flat surface.
Claim 8
Dependent Claim
30 words
A drill as set forth in claim 1 wherein said flat surfaces are at an angle of between 79.5 and 82.5 degrees with respect to said front and back faces.
Claim 9
Dependent Claim
16 words
A drill as set forth in claim 1 wherein said flat surfaces are trapezoidal in shape.
Claim 10
Dependent Claim
16 words
A drill as set forth in claim 1 wherein said flat surfaces lie in different planes.
Claim 11
Dependent Claim
23 words
A drill as set forth in claim 9 wherein said planes intersect each other at an angle of between 15 and 18 degrees.
Claim 12
Dependent Claim
34 words
A drill as set forth in claim 1 wherein said bit has a bore concentric and coextensive with said central axis to permit a lubricant to pass to the area of the cutting tip.
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) | 1982-03-12 | 1982-09-11 | 1983-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-12 | 1986-09-11 | 1987-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-12 | 1990-09-11 | 1991-03-13 | $7700.00 | Window Closed / Lapsed |