Patent US3520449A successfully refreshed from Google Patents.
US3520449A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic shut-off valve for two-fluid sources responsive to depletion of one fluid source
Assignee: Dart Industries Inc
•
Filing: 1968-10-02
•
Granted: 1970-07-14
•
Expires: 1988-10-02
Abstract
No abstract record available.
Inventors
- 👤 Samuel Prussin
- 👤 Jimmie L Mason
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:02
CPC Classifications
B; B65; B65D; B65D83/00; B65D83/14; B65D83/44; B65D83/46; B65D83/68; B65D83/682
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1957011A
Cited
US3217936A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-07-13 | 1974-01-12 | 1974-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-13 | 1978-01-12 | 1978-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-13 | 1982-01-12 | 1982-07-14 | $7700.00 | Window Closed / Lapsed |