US3443752A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control system for gas-fired heating apparatus
Assignee: Fenwal Inc
•
Filing: 1966-07-29
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Granted: 1969-05-13
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Expires: 1986-07-29
Abstract
No abstract record available.
Inventors
- 👤 Lyman H Walbridge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:24
CPC Classifications
F; F23; F23N; F23N5/00; F23N5/20; F23N5/203; F23N5/02; F23N5/14; F23N5/143; F23N2223/00; F23N2223/16; F23N2225/00; F23N2225/08; F23N2227/00; F23N2227/28
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3277949A
Cited
US2467856A
Cited
US2435940A
Cited
US2730304A
Cited
US3247887A
Cited
US3291183A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-05-12 | 1972-11-11 | 1973-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-05-12 | 1976-11-11 | 1977-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-05-12 | 1980-11-11 | 1981-05-13 | $7700.00 | Window Closed / Lapsed |