US2856945A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Demand valve for respiratory apparatus
Assignee: Dunlop Rubber Co Ltd
•
Filing: 1954-10-19
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Granted: 1958-10-21
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Expires: 1974-10-19
Abstract
No abstract record available.
Inventors
- 👤 Trevaskis Henry William
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:20
CPC Classifications
A; A62; A62B; A62B9/00; A62B9/02; A62B9/022; Y; Y10; Y10S; Y10S137/00; Y10S137/908; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7781
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1041636A
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US2071143A
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FR898888A
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US2369170A
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US2375432A
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US2419143A
Cited
US2614573A
Cited
GB693244A
Cited
BE506673A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-10-20 | 1962-04-21 | 1962-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-10-20 | 1966-04-21 | 1966-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-10-20 | 1970-04-21 | 1970-10-21 | $7700.00 | Window Closed / Lapsed |