Patent US4038117A successfully refreshed from Google Patents.
US4038117A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for gas polishing sapphire and the like
Assignee: Excelitas Technologies Illumination Inc
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Filing: 1975-09-04
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Granted: 1977-07-26
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Expires: 1995-09-04
Abstract
Abstract A process for polishing surfaces of sapphire or similar materials to remove surface imperfections visible at magnifications of 1,000X or higher regardless of the shape of the surface, is disclosed, which process comprises the steps of heating the material to an elevated temperature and exposing the surface to be polished to a static hydrogen environment.
Inventors
- 👤 Lowell A. Noble
- 👤 Leonard N. Grossman
- 👤 Mickey O. Marlowe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:14
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B41/53; C04B41/5338; C04B41/5346; C04B41/80; C04B41/91; C30; C30B; C30B29/00; C30B29/10; C30B29/16; C30B29/20; C30B33/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
76 words
The process of surface-polishing bodies of sapphire and the like comprising the steps of heating said body to a temperature of about 1900° C. and exposing at least one surface of said body to substantially static hydrogen gas while maintaining said temperature of about 1900° C. for a time sufficient that no imperfections in said at least one surface can be detected when subsequently examined by a scanning electron microscope at magnifications of at least 1000×.
Claim 2
Dependent Claim
76 words
The process of surface-polishing bodies of sapphire and the like comprising the steps of heating said body to a temperature of about 1900° C. and exposing at least one surface of said body to substantially static hydrogen gas while maintaining said temperature of about 1900° C. for a time sufficient that no imperfections in said at least one surface can be detected when subsequently examined by a scanning electron microscope at magnifications of at least 1000×.
Claim 3
Dependent Claim
36 words
The process of claim 1 wherein said exposure of said at least one surface of said body to substantially static hydrogen gas while maintaining said temperature of about 1900° C. is continued for about 1 hour.
Claim 4
Dependent Claim
18 words
The process of claim 1 wherein said hydrogen gas has a pressure between 1 Torr and 2000 Torr.
Claim 5
Dependent Claim
17 words
The process of claim 1 wherein said hydrogen gas has a dew point less than 50° C.
Claim 6
Dependent Claim
16 words
The process of claim 2 wherein said hydrogen gas has a pressure of about 400 Torr.
Claim 7
Dependent Claim
17 words
The process of claim 5 wherein said hydrogen gas has a dew point of about -80° C.
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) | 1980-07-25 | 1981-01-24 | 1981-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-25 | 1985-01-24 | 1985-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-25 | 1989-01-24 | 1989-07-26 | $7700.00 | Window Closed / Lapsed |