Patent US4145746A successfully refreshed from Google Patents.
US4495698A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Concave grind knife blade and method of making
Assignee: Alterra Holdings Corp
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Filing: 1982-09-01
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Granted: 1985-01-29
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Expires: 2002-09-01
Abstract
Abstract A concavely ground knife blade has a pair of side faces characterized by oppositely-directed, continuous, slightly concave surfaces. Such surfaces have an arcuate profile approximately fitting a large (e.g., 30 inch) radius circle and follow essentially straight line axes which gradually bend toward one another to form a point. The side faces are first ground widthwise along a diameter of a grinding wheel having an end face beveled at a shallow angle to form a frustoconical grinding surface. The side faces are then polished lengthwise. The resultant blade has a median thickness in its midportion which is nearer the back of the blade than the cutting edge.
Inventors
- 👤 Joseph R. Gerber, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:16
CPC Classifications
B; B26; B26B; B26B9/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
93 words
An improved knife blade configuration wherein the blade comprises a pair of opposite side faces, a blunt edge and a sharpened cutting edge, the surface of each side face from said blunt edge to said sharpened cutting edge in a longitudinal mid-portion of the blade being slightly concave about a large, single radius of constant curvature, the blade having a median thickness substantially nearer the blunt edge than the cutting edge over a substantial portion of the length of the blade, the side faces being substantially parallel immediately above the sharpened cutting edge.
Claim 2
Dependent Claim
93 words
An improved knife blade configuration wherein the blade comprises a pair of opposite side faces, a blunt edge and a sharpened cutting edge, the surface of each side face from said blunt edge to said sharpened cutting edge in a longitudinal mid-portion of the blade being slightly concave about a large, single radius of constant curvature, the blade having a median thickness substantially nearer the blunt edge than the cutting edge over a substantial portion of the length of the blade, the side faces being substantially parallel immediately above the sharpened cutting edge.
Claim 3
Dependent Claim
30 words
A blade configuration according to claim 1 in which the concavity of the side faces is defined by an arc approximately fitting a circle having a radius of 30 inches.
Claim 4
Dependent Claim
39 words
A blade configuration according to claim 1 in which the side faces are formed in accordance with an angular segment of a frustoconical surface having a radius of at least 6 inches and a base angle of about 15°.
Claim 5
Dependent Claim
14 words
A blade configuration according to claim 3 in which said radius is 8 inches.
Claim 6
Dependent Claim
31 words
A knife according to claim 1 in which the median thickness is spaced from the cutting edge about 60% of the width of the blade along a midsection of the blade.
Claim 7
Dependent Claim
44 words
A blade configuration according to claim 1 in which the side faces are formed about an axis of concavity extending lengthwise of the blade in a substantially straight line over the entire length of the blade, the cutting edge of the blade being curved.
Claim 8
Dependent Claim
44 words
A blade configuration according to claim 6 in which the blade has an end tapering to a point at which the blunt edge face and cutting edge meet, the side faces of the blade being gradually inclined toward one another proceeding toward said point.
Claim 9
Dependent Claim
39 words
A blade configuration according to claim 6 in which the side faces have, in a region adjacent the point, a nonconcave configuration, said axis being gradually inclined toward the center of the blade but otherwise being a straight line.
References Cited (Backward Citations)
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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) | 1988-01-29 | 1988-07-30 | 1989-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-29 | 1992-07-30 | 1993-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-29 | 1996-07-30 | 1997-01-29 | $7700.00 | Window Closed / Lapsed |