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US2240622A Expired / Lapsed US ⏱️ 0.0 years remaining

Process of filtration utilizing porous cements

Assignee: EIDP Inc
•
Filing: 1939-01-25
•
Granted: 1941-05-06
•
Expires: 1959-01-25
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Abstract

No abstract record available.

Inventors

  • 👤 Lawson Walter Eastby

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 16:30
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/14; B01D39/20; B01D39/2068; B01D39/2093; C; C04; C04B; C04B28/00; C04B28/02; C09; C09K; C09K8/00; C09K8/42; C09K8/46; C09K8/467; C09K8/473; Y; Y10; Y10S; Y10S516/00; Y10S516/01; Y10S516/03

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1944-05-05 1944-11-04 1945-05-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1948-05-05 1948-11-04 1949-05-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1952-05-05 1952-11-04 1953-05-06 $7700.00 Window Closed / Lapsed

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