US3779664A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drill with guide tip
Assignee: Boeing Co
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Filing: 1971-12-30
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Granted: 1973-12-18
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Expires: 1991-12-30
Abstract
Abstract A low-cost, conventional twist drill ground with a unique point configuration that includes a symmetrically-shaped, non-cutting, non-threaded, basically conical tip projecting from the center of the drill point with immediately contiguous cutting edges that enable the drill to generate precision holes in non-ferrous metals and other low-yield strength materials including very thick sections.
Inventors
- 👤 L Caley
- 👤 H Hill
- 👤 J Phillips
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:49
CPC Classifications
B; B23; B23B; B23B51/00; B23B51/02; B23B2251/00; B23B2251/18; Y; Y10; Y10T; Y10T408/00; Y10T408/89; Y10T408/905; Y10T408/906; Y10T408/9065; Y10T408/909; Y10T408/9095; Y10T408/9097
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
108 words
A drill for drilling a straight hole through metal of a thickness greater than the hole diameter comprising a conventional elongated drill body having opposed helical flute surfaces separated by a central web and terminating in a point configuration, said point configuration comprising two primary cutting edges of conventional shape formed by the intersection of the helical flute surfaces and the surface of the point configuration, a non-cutting integral guide tip protuberance formed symmetrically with respect to the longitudinal axis of said drill body and being generally conical in shape and circular in cross-section, and secondary cutting edges formed in said central web adjacent said guide tip protuberance.
Claim 2
Dependent Claim
108 words
A drill for drilling a straight hole through metal of a thickness greater than the hole diameter comprising a conventional elongated drill body having opposed helical flute surfaces separated by a central web and terminating in a point configuration, said point configuration comprising two primary cutting edges of conventional shape formed by the intersection of the helical flute surfaces and the surface of the point configuration, a non-cutting integral guide tip protuberance formed symmetrically with respect to the longitudinal axis of said drill body and being generally conical in shape and circular in cross-section, and secondary cutting edges formed in said central web adjacent said guide tip protuberance.
Claim 3
Dependent Claim
24 words
The combination according to claim 1 wherein the base diameter of said guide tip protuberance is less than the thickness of said central web.
Claim 4
Dependent Claim
34 words
The combination according to claim 1 wherein the point configuration includes a surface segment formed as a radiused transition between the outer surface of said drill body and the surface of said point configuration.
Claim 5
Dependent Claim
127 words
A drill for drilling a straight hole through metal of a thickness greater than the hole diameter comprising a conventional elongated drill body having opposed helical flute surfaces separated by a central web and terminating in a point configuration, said point configuration comprising two primary cutting edges of conventional shape formed by the intersection of the helical flute surfaces and the surface of the point configuration, a non-cutting integral guide tip protuberance formed symmetrically with respect to the longitudinal axis of said drill body and being generally conical in shape and circular in cross-section, the shape of said integral guide tip protuberance being such that at least one of its cross-sectional diameters intersects the helical flute surfaces at the point of minimum thickness of the central web.
Claim 6
Dependent Claim
127 words
A drill for drilling a straight hole through metal of a thickness greater than the hole diameter comprising a conventional elongated drill body having opposed helical flute surfaces separated by a central web and terminating in a point configuration, said point configuration comprising two primary cutting edges of conventional shape formed by the intersection of the helical flute surfaces and the surface of the point configuration, a non-cutting integral guide tip protuberance formed symmetrically with respect to the longitudinal axis of said drill body and being generally conical in shape and circular in cross-section, the shape of said integral guide tip protuberance being such that at least one of its cross-sectional diameters intersects the helical flute surfaces at the point of minimum thickness of the central web.
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) | 1976-12-17 | 1977-06-18 | 1977-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-17 | 1981-06-18 | 1981-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-17 | 1985-06-18 | 1985-12-18 | $7700.00 | Window Closed / Lapsed |