US2987137A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Particle charging apparatus for electrostatic filter
Assignee: Rockwell-Standard Corp
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Filing: 1955-11-16
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Granted: 1961-06-06
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Expires: 1975-11-16
Abstract
No abstract record available.
Inventors
- 👤 Jacob K Brixius
- 👤 Jr Herbert W Trenbath
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:50
CPC Classifications
B; B03; B03C; B03C3/00; B03C3/34; B03C3/86
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) | 1964-06-05 | 1964-12-05 | 1965-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-06-05 | 1968-12-05 | 1969-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-06-05 | 1972-12-05 | 1973-06-06 | $7700.00 | Window Closed / Lapsed |