US2231111A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Indicating switch
Assignee: Kelch Heater Co
•
Filing: 1939-04-17
•
Granted: 1941-02-11
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Expires: 1959-04-17
Abstract
No abstract record available.
Inventors
- 👤 Stuart H Caldwell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:00
CPC Classifications
B; B60; B60K; B60K26/00; B60K26/02; B60K26/021; B60K31/00; B60K31/18; G; G01; G01P; G01P1/00; G01P1/07; G01P1/08; G01P1/10
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) | 1944-02-11 | 1944-08-12 | 1945-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1948-02-11 | 1948-08-12 | 1949-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1952-02-11 | 1952-08-12 | 1953-02-11 | $7700.00 | Window Closed / Lapsed |