US2423172A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Backwashing means for filtering apparatus by reverse flow of filtrate
Assignee: Wallace & Tiernan Co Inc
•
Filing: 1944-04-19
•
Granted: 1947-07-01
•
Expires: 1964-04-19
Abstract
No abstract record available.
Inventors
- 👤 Booth George Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:36
CPC Classifications
B; B01; B01D; B01D37/00; B01D37/02; B01D29/00; B01D29/11; B01D29/31; B01D29/33; B01D29/50; B01D29/52; B01D2201/00; B01D2201/04; B01D2201/043; B01D2201/0446; B01D2201/18; B01D2201/182
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2108798A
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US2165931A
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US2301430A
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US2258063A
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US2332982A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-06-30 | 1950-12-30 | 1951-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-06-30 | 1954-12-30 | 1955-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-06-30 | 1958-12-30 | 1959-07-01 | $7700.00 | Window Closed / Lapsed |