Patent US2881444A successfully refreshed from Google Patents.
US2881444A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Aerodynamic seal for face masks
Assignee: Individual
•
Filing: 1956-05-14
•
Granted: 1959-04-14
•
Expires: 1976-05-14
Abstract
No abstract record available.
Inventors
- 👤 John N Fresh
- 👤 Richard D Murphy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:18
CPC Classifications
A; A61; A61F; A61F9/00; A61F9/02; A61F9/026
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1962-04-13 | 1962-10-13 | 1963-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-04-13 | 1966-10-13 | 1967-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-04-13 | 1970-10-13 | 1971-04-14 | $7700.00 | Window Closed / Lapsed |