US3509901A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic cycling drain valve
Assignee: Westinghouse Air Brake Co
•
Filing: 1967-12-19
•
Granted: 1970-05-05
•
Expires: 1987-12-19
Abstract
No abstract record available.
Inventors
- 👤 Richard E Hollibaugh
- 👤 William S Johnston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:40
CPC Classifications
F; F16; F16K; F16K1/00; F16K1/14; Y; Y10; Y10T; Y10T137/00; Y10T137/2931; Y10T137/3003; Y10T137/3102; Y10T137/3105; Y10T137/8593; Y10T137/86389; Y10T137/86405; Y10T137/86413
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) | 1973-05-04 | 1973-11-03 | 1974-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-05-04 | 1977-11-03 | 1978-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-05-04 | 1981-11-03 | 1982-05-05 | $7700.00 | Window Closed / Lapsed |