Patent US2668976A successfully refreshed from Google Patents.
Patent US2797429A successfully refreshed from Google Patents.
US2797429A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Zone cleaning of precipitator
Assignee: Apra Precipitator Corp
•
Filing: 1952-11-14
•
Granted: 1957-07-02
•
Expires: 1972-11-14
Abstract
No abstract record available.
Inventors
- 👤 Jensen Arthur
- 👤 John C Vickland
- 👤 Roy G Winklepleck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:34
CPC Classifications
B; B03; B03C; B03C3/00; B03C3/34; B03C3/74; B03C3/80
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) | 1960-07-01 | 1960-12-31 | 1961-07-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-07-01 | 1964-12-31 | 1965-07-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-07-01 | 1968-12-31 | 1969-07-02 | $7700.00 | Window Closed / Lapsed |