US2787376A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic check valve for drain pipe
Assignee: Individual
•
Filing: 1954-09-13
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Granted: 1957-04-02
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Expires: 1974-09-13
Abstract
No abstract record available.
Inventors
- 👤 Coulson Walter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:30
CPC Classifications
E; E03; E03F; E03F5/00; E03F5/04; E03F5/042; F; F16; F16K; F16K15/00; F16K15/02; F16K31/00; F16K31/12; F16K31/18; F16K31/20; F16K31/22; Y; Y10; Y10T; Y10T137/00; Y10T137/598; Y10T137/6154; Y10T137/7287; Y10T137/7358; Y10T137/7423; Y10T137/7426; Y10T137/7436; Y10T137/7504; Y10T137/7668
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) | 1960-04-01 | 1960-10-01 | 1961-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-04-01 | 1964-10-01 | 1965-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-04-01 | 1968-10-01 | 1969-04-02 | $7700.00 | Window Closed / Lapsed |