Patent US3381747A successfully refreshed from Google Patents.
US3381747A
Expired / Lapsed
US
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Ventilating system
Assignee: Individual
•
Filing: 1966-05-09
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Granted: 1968-05-07
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Expires: 1986-05-09
Abstract
No abstract record available.
Inventors
- 👤 William J Darm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:38
CPC Classifications
F; F24; F24F; F24F12/00; F24F12/001; Y; Y02; Y02B; Y02B30/00; Y02B30/56; Y10; Y10S; Y10S165/00; Y10S165/355; Y10S165/356; Y10S165/387; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935
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) | 1971-05-07 | 1971-11-06 | 1972-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-05-07 | 1975-11-06 | 1976-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-05-07 | 1979-11-06 | 1980-05-07 | $7700.00 | Window Closed / Lapsed |