US3473542A
Expired / Lapsed
US
⏱️ 0.0 years remaining
In situ pipeline heat generation
Assignee: Shell USA Inc
•
Filing: 1967-09-08
•
Granted: 1969-10-21
•
Expires: 1987-09-08
Abstract
No abstract record available.
Inventors
- 👤 Paul T Chu
- 👤 Clarke L Coldren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:03
CPC Classifications
F; F17; F17D; F17D1/00; F17D1/08; F17D1/16; F17D1/18; Y; Y10; Y10T; Y10T137/00; Y10T137/0318; Y10T137/0391; Y10T137/4891; Y10T137/6416
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1679432A
Cited
US1928226A
Cited
US1841776A
Cited
US2010800A
Cited
US2795560A
Cited
US2824611A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-10-20 | 1973-04-21 | 1973-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-10-20 | 1977-04-21 | 1977-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-10-20 | 1981-04-21 | 1981-10-21 | $7700.00 | Window Closed / Lapsed |