Patent US4722644A successfully refreshed from Google Patents.
US4722644A
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Multi-lip drill
Assignee: Hawera Prazisionswerkzeuge GmbH
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Filing: 1986-01-27
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Granted: 1988-02-02
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Expires: 2006-01-27
Abstract
Abstract A multi-lip drill is proposed in which an additional auxiliary swarf flute is arranged in the core region of one or more principal swarf flutes in order to enlarge the swarf space.
Inventors
- 👤 Anton Scheuch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:36
CPC Classifications
B; B23; B23B; B23B51/00; B23B51/02; B23B2251/00; B23B2251/18; B23B2251/20; B23B2251/202; B23B2251/24; B23B2251/241; Y; Y10; Y10S; Y10S408/00; Y10S408/704; Y10T; Y10T408/00; Y10T408/89; Y10T408/909; Y10T408/9095; Y10T408/9097
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
100 words
In a multi-lip drill having a tip, a plurality of principal cutting edges and a plurality of principal spiral swarf flutes each having a constant radius of curvature R for machining resilient and non-resilient materials, and including an additional auxiliary flute inserted in one of the principal swarf flutes, and oriented parallel thereto for the discharge of swarf, the improvement wherein said auxiliary swarf flute is inserted centrally symmetrically within said one principal swarf flute so that, beginning at the tip of said drill, the depth of the auxiliary swarf flute extends approximately to the center axis of the drill.
Claim 2
Dependent Claim
100 words
In a multi-lip drill having a tip, a plurality of principal cutting edges and a plurality of principal spiral swarf flutes each having a constant radius of curvature R for machining resilient and non-resilient materials, and including an additional auxiliary flute inserted in one of the principal swarf flutes, and oriented parallel thereto for the discharge of swarf, the improvement wherein said auxiliary swarf flute is inserted centrally symmetrically within said one principal swarf flute so that, beginning at the tip of said drill, the depth of the auxiliary swarf flute extends approximately to the center axis of the drill.
Claim 3
Dependent Claim
30 words
Drill according to claim 1, wherein the depth of said auxiliary flute extends at least to 1/10 of the drill diameter in front of the center axis of the drill.
Claim 4
Dependent Claim
50 words
Drill according to claim 1, wherein said auxiliary flute is of arcuate construction in cross-section with a radius of curvature r smaller than the radius of curvature R of said one principal swarf flute, and further including gentle transition regions between said one principal swarf flute and said auxiliary flute.
Claim 5
Dependent Claim
17 words
Drill according to claim 1, wherein the proportion of the radii r:R is approximately 1:3 to 1:4.
Claim 6
Dependent Claim
41 words
Drill according to claim 1, wherein in the region of said tip said auxiliary flute presents a cutting edge and said principal cutting edges have symmetrical transverse cutting edges which are axially in line relative to the auxiliary flute cutting edge.
Claim 7
Dependent Claim
41 words
Drill according to claim 1, wherein in the region of said tip said auxiliary flute presents a cutting edge and said principal cutting edges have symmetrical transverse cutting edges which are axially set back relative to the auxiliary flute cutting edge.
Claim 8
Dependent Claim
17 words
Drill according to claim 1, wherein said drill has an outside diameter of 0.4 to 2.0 mm.
Claim 9
Dependent Claim
19 words
Drill according to claim 1, wherein said plurality of principal cutting edges is composed of three principal cutting edges.
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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) | 1991-02-01 | 1991-08-03 | 1992-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-01 | 1995-08-03 | 1996-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-01 | 1999-08-03 | 2000-02-02 | $7700.00 | Window Closed / Lapsed |