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US3283904A Expired / Lapsed US ⏱️ 0.0 years remaining

Filter element having dual porosities

Assignee: Motors Liquidation Co
•
Filing: 1963-09-09
•
Granted: 1966-11-08
•
Expires: 1983-09-09
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Abstract

No abstract record available.

Inventors

  • 👤 Buckman Kenneth Ernest
  • 👤 Kemp Stanley William
  • 👤 Tuffnell Derrick Percival
  • 👤 Cross Ronald Arthur

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 04:01
CPC Classifications
B; B01; B01D; B01D35/00; B01D35/14; B01D35/147; B01D27/00; B01D27/04; B01D27/06; B01D29/00; B01D29/50; B01D29/52; B01D29/54

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 99 words
A FILTER FOR LIQUID COMPRISING A TUBULAR SUPPORT HAVING OPENINGS THEREIN, TWO FIXED PORTIONS OF FILTER MATERIAL, ONE OF SAID PORTIONS HAVING A FINE POROSITY AND THE OTHER A LESS FINE POROSITY, SAID PORTIONS BEING IN CONTACT WITH AND COVERING AN EXTERIOR SURFACE OF SAID TUBULAR SUPPORT, A PART OF THE SAID EXTERIOR SUPPORT SURFACE CORRESPONDING WITH SAID FINE POROSITY PORTION HAVING A NUMBER OF SAID OPENINGS PER SQUARE INCH OF AREA GREATER THAN A NUMBER OF SAID OPENINGS PER SQUARE INCH OF AREA IN PART OF THE SAID EXTERIOR SUPPORT SURFACE CORRESPONDING WITH SAID LESS FINE POROSITY PORTION.
Claim 2
Dependent Claim 99 words
A FILTER FOR LIQUID COMPRISING A TUBULAR SUPPORT HAVING OPENINGS THEREIN, TWO FIXED PORTIONS OF FILTER MATERIAL, ONE OF SAID PORTIONS HAVING A FINE POROSITY AND THE OTHER A LESS FINE POROSITY, SAID PORTIONS BEING IN CONTACT WITH AND COVERING AN EXTERIOR SURFACE OF SAID TUBULAR SUPPORT, A PART OF THE SAID EXTERIOR SUPPORT SURFACE CORRESPONDING WITH SAID FINE POROSITY PORTION HAVING A NUMBER OF SAID OPENINGS PER SQUARE INCH OF AREA GREATER THAN A NUMBER OF SAID OPENINGS PER SQUARE INCH OF AREA IN PART OF THE SAID EXTERIOR SUPPORT SURFACE CORRESPONDING WITH SAID LESS FINE POROSITY PORTION.

References Cited (Backward Citations)

US3127341A Cited
US2253686A Cited
US2271054A Cited
US2559267A Cited
US2605904A Cited
US2773601A Cited
US2749265A Cited
US2850168A Cited
US2833415A Cited
US2998138A Cited
US3224583A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1969-11-07 1970-05-09 1970-11-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1973-11-07 1974-05-09 1974-11-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1977-11-07 1978-05-09 1978-11-08 $7700.00 Window Closed / Lapsed

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