US2831550A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas filter element
Assignee: MSA Safety Inc
•
Filing: 1957-04-03
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Granted: 1958-04-22
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Expires: 1977-04-03
Abstract
No abstract record available.
Inventors
- 👤 Robert A Bub
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:41
CPC Classifications
B; B01; B01D; B01D46/00; B01D39/00; B01D39/14; B01D39/20; B01D39/2068; B01D39/2082
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) | 1961-04-21 | 1961-10-21 | 1962-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-04-21 | 1965-10-21 | 1966-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-04-21 | 1969-10-21 | 1970-04-22 | $7700.00 | Window Closed / Lapsed |