US3428342A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Connection for sheet metal ducts
Assignee: Individual
•
Filing: 1968-02-28
•
Granted: 1969-02-18
•
Expires: 1988-02-28
Abstract
No abstract record available.
Inventors
- 👤 John E Chambers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:27
CPC Classifications
F; F16; F16L; F16L13/00; F16L13/002
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US574743A
Cited
US1437937A
Cited
US1935690A
Cited
FR1003065A
Cited
US3199901A
Cited
US3357722A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-02-18 | 1972-08-19 | 1973-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-02-18 | 1976-08-19 | 1977-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-02-18 | 1980-08-19 | 1981-02-18 | $7700.00 | Window Closed / Lapsed |