Patent CH134212A successfully refreshed from Google Patents.
US3494638A
Expired / Lapsed
US
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Tubing hanger and seal assembly for well heads
Assignee: BOBBY L FERGUSON
•
Filing: 1967-04-14
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Granted: 1970-02-10
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Expires: 1987-04-14
Abstract
No abstract record available.
Inventors
- 👤 William L Todd
- 👤 Bobby L Ferguson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:34
CPC Classifications
E; E21; E21B; E21B33/00; E21B33/02; E21B33/03; E21B2200/00; E21B2200/01
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1034737A
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US1807046A
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US2205988A
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US2491598A
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US2768841A
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US3185505A
Cited
US2954742A
Cited
US3144066A
Cited
US3376053A
Cited
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 |