US4430223A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filter element for filtering fluid and method of producing same
Assignee: Denso Corp
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Filing: 1982-02-19
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Granted: 1984-02-07
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Expires: 2002-02-19
Abstract
Abstract A filter element of the cylindrical shape for filtering fluid having a constructional form including two-dimensional wave forms radially spreading from the axis of the cylindrical filter element in the form of annular rings, to allow the fluid to flow axially of the filter element. The filter element is produced by using a sheet of filter material in the form of a trapezoid or a segment.
Inventors
- 👤 Susumu Miyakawa
- 👤 Toshiaki Fukuta
- 👤 Hajime Akado
- 👤 Yoshihiro Taki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:25
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/52; B01D46/521; B01D46/523; B01D27/00; B01D27/04; B01D27/06; B01D29/00; B01D29/01; B01D29/012; B01D29/05; B01D29/07; B01D29/073; B01D46/10; B01D2201/00; B01D2201/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
184 words
A cylindrical filter element for filtering fluid, having two-dimensional wave forms spreading radially from the axis of said cylindrical element and including a plurality of closed wave crest lines, and being produced through the steps of preparing a filter material strip shaped symmetrical with respect to a center line extending from narrower one end to the wider other end of the strip, of folding said filter strip along a plurality of folding lines substantially perpendicular to the center line to form parallel wave forms between the two ends, and of curving and closing the folded filter strip in such a manner that said narrower end is located on the inner peripheral side of the curved filter strip and said wider end on the outer peripheral side, characterized in that at least one interval between adjacent two of said folding lines is different from at least one of the other intervals, and thus, at least one crest line or bottom line of said two-dimensional wave form is different from at least one of the other crest lines or bottom lines with respect to their heights.
Claim 2
Dependent Claim
184 words
A cylindrical filter element for filtering fluid, having two-dimensional wave forms spreading radially from the axis of said cylindrical element and including a plurality of closed wave crest lines, and being produced through the steps of preparing a filter material strip shaped symmetrical with respect to a center line extending from narrower one end to the wider other end of the strip, of folding said filter strip along a plurality of folding lines substantially perpendicular to the center line to form parallel wave forms between the two ends, and of curving and closing the folded filter strip in such a manner that said narrower end is located on the inner peripheral side of the curved filter strip and said wider end on the outer peripheral side, characterized in that at least one interval between adjacent two of said folding lines is different from at least one of the other intervals, and thus, at least one crest line or bottom line of said two-dimensional wave form is different from at least one of the other crest lines or bottom lines with respect to their heights.
Claim 3
Dependent Claim
79 words
A cylindrical filter element as claimed in claim 1, characterized in that said intervals are classified into two groups, one group of shorter regular intervals adjacent to each other and opposing to said narrower end and the other group of longer regular intervals adjacent to each other and opposing to said wider end, so that amplitudes of waves in said two-dimensional wave form are smaller in the radially inside region of said wave form than in the outside region.
Claim 4
Dependent Claim
58 words
A cylindrical filter element as claimed in claim 1, characterized in that one of said intervals located substantially at the midportion of said strip is longer than the other intervals of constant length, so that the crests or bottoms of said waves stepwisely vary with respect to their heights substantially at the radial midpoint of said wave form.
Claim 5
Dependent Claim
54 words
A cylindrical filter element as claimed in claim 1, characterized in that said intervals are composed of longer intervals and shorter intervals, a longer interval and a shorter interval being arranged alternately, so that the crest lines of said two-dimensional wave form vary with respect to their heights successively with a constant height difference.
Claim 6
Dependent Claim
41 words
A cylindrical filter element as claimed in claim 1, characterized in that said filter material strip has a shape of truncated sector, and said narrower and wider ends of the strip and said folding lines have arc-shapes having a common center.
Claim 7
Dependent Claim
27 words
A cylindrical filter element as claimed in claim 1, characterized in that said filter material strip has a shape of trapezoid, and said folding lines are straight.
Claim 8
Dependent Claim
31 words
A cylindrical filter element as claimed in claim 1, characterized in that said filter material strip has a shape of sector, and said folding lines have arc-shapes having a common center.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-02-06 | 1987-08-08 | 1988-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-06 | 1991-08-08 | 1992-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-06 | 1995-08-08 | 1996-02-07 | $7700.00 | Window Closed / Lapsed |