US2721747A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic shaft seal
Assignee: Read Standard Corp
•
Filing: 1951-12-21
•
Granted: 1955-10-25
•
Expires: 1971-12-21
Abstract
No abstract record available.
Inventors
- 👤 Joseph E Whitfield
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:31
CPC Classifications
F; F16; F16J; F16J15/00; F16J15/16; F16J15/40
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US1759074A
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US2245281A
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US2356011A
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US2347296A
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GB636298A
Cited
US2555492A
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FR981140A
Cited
GB657396A
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US2632395A
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US2602680A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1958-10-24 | 1959-04-25 | 1959-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-10-24 | 1963-04-25 | 1963-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-10-24 | 1967-04-25 | 1967-10-25 | $7700.00 | Window Closed / Lapsed |