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US2566809A
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US
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Knife sharpener
Assignee: Dresser Industries Inc
•
Filing: 1947-10-31
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Granted: 1951-09-04
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Expires: 1967-10-31
Abstract
No abstract record available.
Inventors
- 👤 Roger E Risley
- 👤 Paul B Scharf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:40
CPC Classifications
B; B24; B24B; B24B21/00; B24B21/002; B24B3/00; B24B3/36; B24B3/54
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US644211A
Cited
FR463311A
Cited
US1246958A
Cited
US1276601A
Cited
US1821624A
Cited
GB352754A
Cited
US2222966A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-09-03 | 1955-03-05 | 1955-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-09-03 | 1959-03-05 | 1959-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-09-03 | 1963-03-05 | 1963-09-04 | $7700.00 | Window Closed / Lapsed |