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Patent US3443121A successfully refreshed from Google Patents.
US3443121A
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Time proportioning temperature control system
Assignee: API Instruments Co
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Filing: 1965-12-20
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Granted: 1969-05-06
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Expires: 1985-12-20
Abstract
No abstract record available.
Inventors
- 👤 Stephen P Weisbrod
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:20
CPC Classifications
G; G05; G05B; G05B11/00; G05B11/01; G05B11/26; G05B11/28; G05D; G05D23/00; G05D23/19; G05D23/1906; G05D23/1913; G05D23/20; G05D23/22
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3036188A
Cited
US3180974A
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US3231719A
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US3301482A
Cited
US3300622A
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US3325716A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-05-05 | 1972-11-04 | 1973-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-05-05 | 1976-11-04 | 1977-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-05-05 | 1980-11-04 | 1981-05-06 | $7700.00 | Window Closed / Lapsed |