US1947447A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for the filtration of air or gases
Assignee: Brassert & Co
•
Filing: 1932-01-11
•
Granted: 1934-02-20
•
Expires: 1952-01-11
Abstract
No abstract record available.
Inventors
- 👤 Herman A Brassert
- 👤 Arthur J Boynton
- 👤 John P Grilli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:10
CPC Classifications
H; H03; H03D; H03D3/00; H03D3/02; H03D3/06; H03D3/12; B; B03; B03C; B03C3/00; B03C3/34; B03C3/74; B03C3/78; Y; Y10; Y10S; Y10S15/00; Y10S15/08; Y10S55/00; Y10S55/34
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1937-02-19 | 1937-08-21 | 1938-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1941-02-19 | 1941-08-21 | 1942-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1945-02-19 | 1945-08-21 | 1946-02-20 | $7700.00 | Window Closed / Lapsed |