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US3759391A Expired / Lapsed US ⏱️ 0.0 years remaining

Coiled filter element and method of manufacturing the same

Assignee: Robert Bosch GmbH
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Filing: 1972-10-02
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Granted: 1973-09-18
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Expires: 1992-10-02
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Abstract

Abstract An elongated strip of filter material is wound into a coil and consists of two superimposed strip portions connected to each other at their one side and spaced from each other at their opposite side. The strip portions, in consecutive windings of the strip, are spaced from each other at their connected sides and connected at their spaced sides to respectively form first and second parallel adjoining filter pockets of substantially Vshaped cross section, open at the opposite end faces of the coil. Transverse corrugations are provided in the strip portions and afford adjustments in the length of the respective strip portions to the extent such adjustments are necessary during the convoluting of the strip portions into coil shape.

Inventors

  • 👤 A Dreher

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 11:56
CPC Classifications
B; B01; B01D; B01D25/00; B01D25/22; B01D25/24

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 222 words
A coiled filter element, comprising a coil of an elongated strip of filter material transversely folded upon itself so as to produce superimposed longitudinally coextensive strip portions each having two longitudinally extending margins respectively located at one and at another lateral side of said strip, said strip portions being of one piece with one another along said margins of said other lateral side of said strip; a plurality of at least substantially parallel corrugations provided in each of said strip portions and extending transversely to the elongation of said strip, the convolutions of said strip defining two spirally convoluted internal filter pockets one of which is open at one axial end of the coil and the other of which is open at the other axial end of the coil, and said corrugations enabling compensation of length variations which occur due to convoluting of said strip in one of said strip portions with reference to the other strip portion with which said one strip portion is of one piece along said margins at said other lateral side; and sealing means sealingly connected consecutive convolutions of said coil in the region of one of said axial ends of the coil, which end lies opposite to said other lateral side of said strip at which said strip portions are of one piece with one another.
Claim 2
Dependent Claim 222 words
A coiled filter element, comprising a coil of an elongated strip of filter material transversely folded upon itself so as to produce superimposed longitudinally coextensive strip portions each having two longitudinally extending margins respectively located at one and at another lateral side of said strip, said strip portions being of one piece with one another along said margins of said other lateral side of said strip; a plurality of at least substantially parallel corrugations provided in each of said strip portions and extending transversely to the elongation of said strip, the convolutions of said strip defining two spirally convoluted internal filter pockets one of which is open at one axial end of the coil and the other of which is open at the other axial end of the coil, and said corrugations enabling compensation of length variations which occur due to convoluting of said strip in one of said strip portions with reference to the other strip portion with which said one strip portion is of one piece along said margins at said other lateral side; and sealing means sealingly connected consecutive convolutions of said coil in the region of one of said axial ends of the coil, which end lies opposite to said other lateral side of said strip at which said strip portions are of one piece with one another.
Claim 3
Dependent Claim 29 words
A filter element as defined in claim 1, and further comprising spacing means extending along said margins in the region of one of said axial ends of the coil.
Claim 4
Dependent Claim 26 words
A filter element as defined in claim 2, wherein said spacing means extending along said margins at said other lateral side and spaces said margins apart.
Claim 5
Dependent Claim 40 words
A filter element as defined in claim 2, wherein said spacing means comprises a spacing strip having a width substantially smaller than the width of said strip portions and extending along at least substantially the entire Length of the latter.
Claim 6
Dependent Claim 32 words
A filter element as defined in claim 4, wherein said spacing strip has longitudinally adjacent transverse corrugations spaced and configurated differently from said corrugations of said strip portions for preventing interengagement therewith.
Claim 7
Dependent Claim 53 words
A filter element as defined in claim 1, and further comprising first spacing means extending between the margins of said strip portions at said one lateral side and spacing said margins apart; and second spacing means extending along the margins at said other lateral side and spacing apart consecutive convolutions of the coil.
Claim 8
Dependent Claim 20 words
A filter element as defined in claim 1, wherein said corrugations are spaced at identical distances longitudinally of said strip.
Claim 9
Dependent Claim 20 words
A filter element as defined in claim 1, wherein said corrugations extend over the entire width of said strip portions.
Claim 10
Dependent Claim 43 words
A filter element as defined in claim 1, wherein said corrugations extend over only part of the width of said strip portions, and wherein said margins of said strip portions are free from said corrugations at least at one of said lateral sides.
Claim 11
Dependent Claim 159 words
Method of manufacturing a coiled filter element, comprising the steps of forming an elongated strip of filter material transversely folded upon itself so as to produce superimposed longitudinally coextensive strip portions extending lengthwise of said strip and each having two longitudinally extending margins located at opposite lateral sides of said strip, with the margins at one lateral side of said strip portions being of one piece with each other; forming a plurality of at least substantially parallel transverse corrugations in each of said strip portions of said elongated strip; providing adhesive means on said strip portions along said margins at the other lateral side of said strip; and convoluting said strip to form a coiled element having a plurality of convolutions forming a pair of spirally convoluted filter pockets one of which is open at one axial end of said coiled element and the other of which is open at the other axial end of said coiled filter element.
Claim 12
Dependent Claim 159 words
Method of manufacturing a coiled filter element, comprising the steps of forming an elongated strip of filter material transversely folded upon itself so as to produce superimposed longitudinally coextensive strip portions extending lengthwise of said strip and each having two longitudinally extending margins located at opposite lateral sides of said strip, with the margins at one lateral side of said strip portions being of one piece with each other; forming a plurality of at least substantially parallel transverse corrugations in each of said strip portions of said elongated strip; providing adhesive means on said strip portions along said margins at the other lateral side of said strip; and convoluting said strip to form a coiled element having a plurality of convolutions forming a pair of spirally convoluted filter pockets one of which is open at one axial end of said coiled element and the other of which is open at the other axial end of said coiled filter element.

References Cited (Backward Citations)

US2564637A Cited
GB755481A Cited
US3279616A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-09-17 1977-03-19 1977-09-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-09-17 1981-03-19 1981-09-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-09-17 1985-03-19 1985-09-18 $7700.00 Window Closed / Lapsed

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