US2928491A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sound and gas-flow control unit
Assignee: Individual
•
Filing: 1955-02-21
•
Granted: 1960-03-15
•
Expires: 1975-02-21
Abstract
No abstract record available.
Inventors
- 👤 John M Crouch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:54
CPC Classifications
F; F01; F01N; F01N1/00; F01N1/08
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
DE554601C
Cited
US2732026A
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GB190121554A
Cited
US734878A
Cited
US787860A
Cited
US1049433A
Cited
US991515A
Cited
US1074627A
Cited
US2012331A
Cited
FR992706A
Cited
US2806548A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-03-15 | 1963-09-14 | 1964-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-03-15 | 1967-09-14 | 1968-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-03-15 | 1971-09-14 | 1972-03-15 | $7700.00 | Window Closed / Lapsed |