Patent US1517587A successfully refreshed from Google Patents.
US2145844A
Expired / Lapsed
US
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Well head apparatus
Assignee: Individual
•
Filing: 1936-09-01
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Granted: 1939-02-07
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Expires: 1956-09-01
Abstract
No abstract record available.
Inventors
- 👤 Clcero C Brown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:50
CPC Classifications
E; E21; E21B; E21B33/00; E21B33/02; E21B33/03; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/877; Y10T137/87901
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1942-02-06 | 1942-08-08 | 1943-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1946-02-06 | 1946-08-08 | 1947-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1950-02-06 | 1950-08-08 | 1951-02-07 | $7700.00 | Window Closed / Lapsed |