US2640560A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dust filtering apparatus
Assignee: MSA Safety Inc
•
Filing: 1951-12-29
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Granted: 1953-06-02
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Expires: 1971-12-29
Abstract
No abstract record available.
Inventors
- 👤 John M Lewis
- 👤 Robert A Bub
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:07
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/02; B01D46/06; Y; Y10; Y10S; Y10S55/00; Y10S55/12
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) | 1956-06-01 | 1956-12-01 | 1957-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-01 | 1960-12-01 | 1961-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-01 | 1964-12-01 | 1965-06-02 | $7700.00 | Window Closed / Lapsed |