Patent US3402785A successfully refreshed from Google Patents.
US3402785A
Expired / Lapsed
US
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Muffler with resonance chambers for high and low frequencies
Assignee: Walker Manufacturing Co
•
Filing: 1965-10-23
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Granted: 1968-09-24
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Expires: 1985-10-23
Abstract
No abstract record available.
Inventors
- 👤 Walter H Powers
- 👤 Robert A Heath
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:41
CPC Classifications
F; F01; F01N; F01N1/00; F01N1/003; F01N1/006; F01N1/02; F01N1/023; F01N2490/00; F01N2490/14; F01N2490/15; F01N2490/155
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-09-24 | 1972-03-25 | 1972-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-09-24 | 1976-03-25 | 1976-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-09-24 | 1980-03-25 | 1980-09-24 | $7700.00 | Window Closed / Lapsed |