Patent US3521761A successfully refreshed from Google Patents.
US3521761A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Work transfer mechanism
Assignee: Individual
•
Filing: 1969-03-13
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Granted: 1970-07-28
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Expires: 1989-03-13
Abstract
No abstract record available.
Inventors
- 👤 Bernard J Wallis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:59
CPC Classifications
B; B21; B21D; B21D43/00; B21D43/02; B21D43/04; B21D43/05; B21D43/055
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3430782A
Cited
US3432042A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-07-27 | 1974-01-26 | 1974-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-27 | 1978-01-26 | 1978-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-27 | 1982-01-26 | 1982-07-28 | $7700.00 | Window Closed / Lapsed |