US5121660A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Razor blade technology
Assignee: Gillette Co LLC
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Filing: 1991-10-09
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Granted: 1992-06-16
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Expires: 2011-10-09
Abstract
Abstract A process for forming a razor blade includes the steps of providing a polycrystalline ceramic substrate of less than two micrometer grain size, mechanically abrading an edge of the polycrystalline ceramic substrate to form a sharpened edge thereon that has an included angle of less than twenty degrees; and sputter-etching the sharpened edge to reduce the tip radius to less than 300 Angstroms and form a cutting edge. The resulting blades exhibit excellent shaving properties.
Inventors
- 👤 Carolyn M. Kramer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:12
CPC Classifications
B; B26; B26B; B26B21/00; B26B21/54; Y; Y10; Y10S; Y10S76/00; Y10S76/08
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
70 words
A process for forming a razor blade comprising steps of providing a polycrystalline ceramic substrate that has a grain size of less than two micrometers, mechanically abrading an edge of said polycrystalline ceramic substrate to form a sharpened edge thereon that has an included angle of less than twenty degrees; and sputter-etching said sharpened edge to form a cutting edge that has a tip radius of less than 300 Angstroms.
Claim 2
Dependent Claim
70 words
A process for forming a razor blade comprising steps of providing a polycrystalline ceramic substrate that has a grain size of less than two micrometers, mechanically abrading an edge of said polycrystalline ceramic substrate to form a sharpened edge thereon that has an included angle of less than twenty degrees; and sputter-etching said sharpened edge to form a cutting edge that has a tip radius of less than 300 Angstroms.
Claim 3
Dependent Claim
28 words
The process of claim 1 wherein said polycrystalline ceramic substrate is mechanically abraded in a sequence of grinding, rough honing and finish honing steps with diamond abrasive material.
Claim 4
Dependent Claim
36 words
The process of claim 1 wherein said step of mechanically abrading an edge of said polycrystalline ceramic substrate forms a sharpened edge thereon that has a tip radius in the range of 600 to 1000 Angstroms.
Claim 5
Dependent Claim
28 words
The process of claim 1 wherein said polycrystalline ceramic substrate material is selected from the group consisting of silicon carbide, silicon nitride, mullite, hafnia, yttria, zirconia, and alumina.
Claim 6
Dependent Claim
18 words
The process of claim 1 wherein said ceramic substrate has a bend strength in excess of 300 MPa.
Claim 7
Dependent Claim
36 words
The process of claim 1 and further including the steps of sputter depositing a layer of electrically conductive metal on said cutting edge, and then applying an adherent polymer coating on said metal coated cutting edge.
Claim 8
Dependent Claim
45 words
The process of claim 6 wherein said sputter-deposited layer of electrically conductive metal on said cutting edge has a thickness of less than five hundred Angstroms, and said adherent polymer coating on said metal coated cutting edge has a thickness of less than ten micrometers.
Claim 9
Dependent Claim
21 words
The process of claim 6 wherein said polycrystalline ceramic substrate material is selected from the group consisting of alumina and zirconia.
Claim 10
Dependent Claim
49 words
The process of claim 1 wherein said sputter-etching of said sharpened edge to form said cutting edge provides sputter-etched surfaces immediately adjacent said cutting edge of width in the range of 0.01-0.3 micrometer and an effective included angle substantially greater than the included angle of said mechanically abraded facets.
Claim 11
Dependent Claim
91 words
The process of claim 9 wherein said polycrystalline ceramic substrate material is selected from the group consisting of pure alumina and hot-isostatically-pressed tetragonal zirconia that has a bend strength in excess of 300 MPa and a grain size of less than 0.5 micrometers, and further including the steps of sputter depositing a layer of electrically conductive metal on said cutting edge to a thickness of less than five hundred Angstroms, and then applying an adherent polymer coating on said metal coated cutting edge to a thickness of less than ten micrometers.
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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) | 1995-06-16 | 1995-12-16 | 1996-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-16 | 1999-12-16 | 2000-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-16 | 2003-12-16 | 2004-06-16 | $7700.00 | Window Closed / Lapsed |