Patent US3494348A successfully refreshed from Google Patents.
US3494348A
Expired / Lapsed
US
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Core drill
Assignee: NATIONAL GRINDING WHEEL Co Inc
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Filing: 1967-02-20
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Granted: 1970-02-10
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Expires: 1987-02-20
Abstract
No abstract record available.
Inventors
- 👤 Frederick W Lindblad
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:49
CPC Classifications
B; B28; B28D; B28D1/00; B28D1/02; B28D1/04; B28D1/041; E; E21; E21B; E21B10/00; E21B10/46; E21B10/48
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) | 1973-02-09 | 1973-08-11 | 1974-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-02-09 | 1977-08-11 | 1978-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-02-09 | 1981-08-11 | 1982-02-10 | $7700.00 | Window Closed / Lapsed |