US3516541A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drain safety device
Assignee: Individual
•
Filing: 1968-11-07
•
Granted: 1970-06-23
•
Expires: 1988-11-07
Abstract
No abstract record available.
Inventors
- 👤 Derek D Hardingham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:17
CPC Classifications
E; E03; E03F; E03F5/00; E03F5/04; E03F5/0407; E03F2005/0416
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) | 1973-06-22 | 1973-12-22 | 1974-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-06-22 | 1977-12-22 | 1978-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-06-22 | 1981-12-22 | 1982-06-23 | $7700.00 | Window Closed / Lapsed |