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US4268290A Expired / Lapsed US ⏱️ 0.0 years remaining

Air filters

Assignee: Engineering Components Ltd
•
Filing: 1979-05-31
•
Granted: 1981-05-19
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Expires: 1999-05-31
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Abstract

Abstract A pleated paper filter element has the configuration of the frustrum of a cone with the pleats extending lengthwise of the sloping wall of the cone and has pleat separation dimples embossed into the paper from which the element is made, the height of said dimples being graduated lengthwise of the element so as to provide controlled pleat separation over at least most of the length of the element.

Inventors

  • 👤 Ross B. Barrington

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 19:05
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/52; B01D46/521; B01D46/523; B01D46/24; B01D46/2403; B01D46/2411; F; F02; F02M; F02M35/00; F02M35/02; F02M35/024; B01D2201/00; B01D2201/12; B01D2201/127; B01D2275/00; B01D2275/20; B01D2275/201; B01D2279/00; B01D2279/60

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 80 words
A paper filter frusto-conical element having a frusto-conical sloping wall with pleats extending lengthwise thereof, said pleats including dimples embossed into the paper from which the pleat is formed and arranged to abut an adjacent pleat for control of separation of adjacent pleats, the height of said dimples situated at positions spaced along said sloping wall being graduated lengthwise of the element so as to provide controlled pleat separation over at least most of the length of the filter element.
Claim 2
Dependent Claim 80 words
A paper filter frusto-conical element having a frusto-conical sloping wall with pleats extending lengthwise thereof, said pleats including dimples embossed into the paper from which the pleat is formed and arranged to abut an adjacent pleat for control of separation of adjacent pleats, the height of said dimples situated at positions spaced along said sloping wall being graduated lengthwise of the element so as to provide controlled pleat separation over at least most of the length of the filter element.
Claim 3
Dependent Claim 58 words
A pleated paper filter element according to claim 1, wherein the pleat separation dimples each have the form of a tapered indent comprising a continuous deformation extending over at least a major portion of the pleat depth to form a ridge whose height relative to the plane of the paper decreases progressively towards the bottom of the pleat.
Claim 4
Dependent Claim 68 words
A pleated paper filter element according to claim 2 wherein the pleat separation dimples which project from the plane of the paper in that direction which in use is towards the outer surface of the tapered element are tapered indents and those pleat separation dimples projecting from the plane of the paper in the opposite direction are of substantially constant height throughout the depth of any one pleat.
Claim 5
Dependent Claim 33 words
A pleated paper filter element according to claim 1 wherein the pleat separation dimples are formed so as to lie in crest-to-crest abutting relation when the paper is assembled into a filter element.
Claim 6
Dependent Claim 39 words
A pleated paper filter element according to claim 4 wherein the pleat separation dimples have a height of about 1 mm relative to the plane of the paper and their abutting regions are from 1 to 3 mm wide.

References Cited (Backward Citations)

GB840757A Cited
US2936855A Cited
US2968361A Cited
US3531920A Cited
DE2034669A1 Cited
GB1507824A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1984-05-18 1984-11-17 1985-05-19 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1988-05-18 1988-11-17 1989-05-19 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1992-05-18 1992-11-17 1993-05-19 $7700.00 Window Closed / Lapsed

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