Patent US3576727A successfully refreshed from Google Patents.
Patent US3570220A successfully refreshed from Google Patents.
US3570220A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Combined access door and filter holder
Assignee: Individual
•
Filing: 1969-04-02
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Granted: 1971-03-16
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Expires: 1989-04-02
Abstract
Abstract COMBINED ACCESS DOOR AND FILTER HOLDER WHEREIN THE FILTER HOLDER OPENS INWARDLY OF THE ACCESS DOOR, ADAPTED FOR USE OF INEXPENSIVE FILTER MEDIA SUPPLIED IN FLAT SHEETS OR ROLLS, WHICH IS CUT TO SIZE FOR PLACEMENT IN THE FILTER HOLDER WHICH HOLDS THE FILTER MEDIA IN ADEQUATELY SUPPORTED CONDITIONS.
Inventors
- 👤 John V Felter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:28
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/10; F; F24; F24F; F24F13/00; F24F13/28
Claims Analysis
Total Claims: 0
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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) | 1974-03-15 | 1974-09-14 | 1975-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-15 | 1978-09-14 | 1979-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-15 | 1982-09-14 | 1983-03-16 | $7700.00 | Window Closed / Lapsed |