US2809657A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic low pressure safety valve
Assignee: Individual
•
Filing: 1954-04-02
•
Granted: 1957-10-15
•
Expires: 1974-04-02
Abstract
No abstract record available.
Inventors
- 👤 Earl P Stephenson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:27
CPC Classifications
F; F16; F16K; F16K17/00; F16K17/02; F16K17/164; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7723; Y10T137/7731
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-10-14 | 1961-04-15 | 1961-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-10-14 | 1965-04-15 | 1965-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-10-14 | 1969-04-15 | 1969-10-15 | $7700.00 | Window Closed / Lapsed |