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Patent US2741260A successfully refreshed from Google Patents.
US2741260A
Expired / Lapsed
US
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Automatic device for preventing unwanted outflow of gases from one space to another
Assignee: Hartford National Bank and Trust Co
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Filing: 1952-06-12
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Granted: 1956-04-10
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Expires: 1972-06-12
Abstract
No abstract record available.
Inventors
- 👤 Verhoeff Adrianus
- 👤 Vries Wopke De
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:47
CPC Classifications
F; F22; F22B; F22B37/00; F22B37/78; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7723; Y10T137/7726; Y10T137/7727
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-04-10 | 1959-10-10 | 1960-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-04-10 | 1963-10-10 | 1964-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-04-10 | 1967-10-10 | 1968-04-10 | $7700.00 | Window Closed / Lapsed |