US2838644A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic thermoregulator
Assignee: Shell Development Co
•
Filing: 1956-01-20
•
Granted: 1958-06-10
•
Expires: 1976-01-20
Abstract
No abstract record available.
Inventors
- 👤 Francis B Rolfson
- 👤 William B Milligan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:29
CPC Classifications
G; G05; G05D; G05D23/00; G05D23/19; G05D23/20; G05D23/24; G05D23/2451; G05D23/2453; Y; Y10; Y10S; Y10S236/00; Y10S236/14
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2383456A
Cited
US2488580A
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US2518108A
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US2522753A
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US2724040A
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US2761052A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-06-09 | 1961-12-09 | 1962-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-06-09 | 1965-12-09 | 1966-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-06-09 | 1969-12-09 | 1970-06-10 | $7700.00 | Window Closed / Lapsed |