Patent US3397521A successfully refreshed from Google Patents.
US3397521A
Expired / Lapsed
US
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Rotatable double-headed lawnmower
Assignee: Danuser Machine Works Inc
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Filing: 1964-12-15
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Granted: 1968-08-20
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Expires: 1984-12-15
Abstract
No abstract record available.
Inventors
- 👤 Walter W Danuser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:48
CPC Classifications
A; A01; A01D; A01D34/00; A01D34/01; A01D34/412; A01D34/63; A01D34/67; A01D34/68; A01D34/685; A01D34/835; A01D34/86; A01D34/863; A01D2101/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2976663A
Cited
US2838901A
Cited
US2926480A
Cited
US3200574A
Cited
US3246460A
Cited
US3183651A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-08-20 | 1972-02-19 | 1972-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-08-20 | 1976-02-19 | 1976-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-08-20 | 1980-02-19 | 1980-08-20 | $7700.00 | Window Closed / Lapsed |