US3077931A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multi-purpose wellhead apparatus for oil wells
Assignee: Shaffer Tool Works
•
Filing: 1960-01-04
•
Granted: 1963-02-19
•
Expires: 1980-01-04
Abstract
No abstract record available.
Inventors
- 👤 Donald U Shaffer
- 👤 Eugene C Greenwood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:44
CPC Classifications
E; E21; E21B; E21B33/00; E21B33/02; E21B33/03; E21B33/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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DE1086643B
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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) | 1966-02-18 | 1966-08-20 | 1967-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-02-18 | 1970-08-20 | 1971-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-02-18 | 1974-08-20 | 1975-02-19 | $7700.00 | Window Closed / Lapsed |