US3538945A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Constant volume regulator for air duct systems
Assignee: FIRST MISSOURI DEV FINANCE CORP
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Filing: 1967-12-21
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Granted: 1970-11-10
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Expires: 1987-12-21
Abstract
No abstract record available.
Inventors
- 👤 Frank J Dean Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:10
CPC Classifications
G; G05; G05D; G05D7/00; G05D7/01; G05D7/0173; F; F24; F24F; F24F11/00; F24F11/70; F24F11/72; F24F11/74; F24F11/75; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7781; Y10T137/7784; Y10T137/7786; Y10T137/7837; Y10T137/7869; Y10T137/7875
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) | 1973-11-09 | 1974-05-11 | 1974-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-11-09 | 1978-05-11 | 1978-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-11-09 | 1982-05-11 | 1982-11-10 | $7700.00 | Window Closed / Lapsed |