Patent US2646146A successfully refreshed from Google Patents.
US2646146A
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US
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Clutch for drill heads
Assignee: CRICHTON Co
•
Filing: 1948-04-19
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Granted: 1953-07-21
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Expires: 1968-04-19
Abstract
No abstract record available.
Inventors
- 👤 Jr Andrew B Crichton
- 👤 Carl G Wennerstrom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 17:32
CPC Classifications
E; E21; E21B; E21B3/00; E21B3/02; E21B3/035; F; F16; F16D; F16D7/00; F16D7/02; F16D7/024; F16D7/025; F16D7/027; Y; Y10; Y10T; Y10T408/00; Y10T408/70; Y10T408/72
Claims Analysis
Total Claims: 0
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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) | 1956-07-20 | 1957-01-19 | 1957-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-07-20 | 1961-01-19 | 1961-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-07-20 | 1965-01-19 | 1965-07-21 | $7700.00 | Window Closed / Lapsed |