Patent US3447644A successfully refreshed from Google Patents.
US3447644A
Expired / Lapsed
US
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Two stage shock absorber
Assignee: Woodhead Manufacturing Co Ltd
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Filing: 1967-03-09
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Granted: 1969-06-03
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Expires: 1987-03-09
Abstract
No abstract record available.
Inventors
- 👤 William A Duckett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 04:53
CPC Classifications
F; F16; F16F; F16F9/00; F16F9/32; F16F9/48; F16F9/49
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1539196A
Cited
US2629462A
Cited
GB696206A
Cited
US2783859A
Cited
US3150747A
Cited
US3378110A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-06-02 | 1972-12-02 | 1973-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-06-02 | 1976-12-02 | 1977-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-06-02 | 1980-12-02 | 1981-06-03 | $7700.00 | Window Closed / Lapsed |