US2257249A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic change-over device
Assignee: Phillips Petroleum Co
•
Filing: 1938-07-18
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Granted: 1941-09-30
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Expires: 1958-07-18
Abstract
No abstract record available.
Inventors
- 👤 Rosswell W Thomas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:36
CPC Classifications
F; F17; F17C; F17C13/00; F17C13/04; F17C13/045; Y; Y10; Y10T; Y10T137/00; Y10T137/2496; Y10T137/2559; Y10T137/2564; Y10T137/2567; Y10T137/2569; Y10T137/5109; Y10T137/5196; Y10T137/7722; Y10T137/7758; Y10T137/7762; Y10T137/7781; Y10T137/7793; Y10T137/7795; Y10T137/7837; Y10T137/7838; Y10T137/7845; Y10T137/8593; Y10T137/87056; Y10T137/87571; Y10T137/87676; Y10T137/87684
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) | 1944-09-29 | 1945-03-31 | 1945-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1948-09-29 | 1949-03-31 | 1949-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1952-09-29 | 1953-03-31 | 1953-09-30 | $7700.00 | Window Closed / Lapsed |