Pleated air filter

Claim 2

A fluid filter element adapted for a flat silhouette type fluid filter construction comprising a sheet of filter material having a series of substantially V-shaped pleats formed therein, each pleat having a pair of sides and adjacent pleats being oppositely directed and having a common side, and at least one end portion of each of said pleat sides having score lines therein and being transversely bent along said score lines to provide a tuck of predetermined shape and position in each said end portion, each said tuck tapering in height as it approaches the outer edge of the pleat side to provide an outer pleat edge that is substantially shorter than the main portion of the pleat, said score lines including a V-shaped portion located in each pleat side to provide for said tuck taper along opposite longitudinal portions of each pleat side, said score lines including a stem extending from the apex of said V-shaped portion to provide a Y-shaped portion and the Y-stem aligned portions of the pleat sides being crushed to form a rim for the filter material.

Claim 3

A filter as set forth in claim 1 wherein said score lines include a line extending transversely across each pleat side at substantially the tip ends of each V-shaped score line portion and defining the inner end of the tuck in said pleat side.

Claim 4

A filter element for air or the like comprising a sheet of pleated filter material in the form of an annulus with the pleats extending radially of the axis of the annulus and across the full width of the annulus, each pleat comprising two radially extending sides and adjacent pleats having a common side, said sides having inner and outer end portions and the sheet having score lines therein located in said end portions, said end portions being bent and folded about said score lines to form inner and outer mounting rims comprising at least two layers of said sheet in face to face contact with each other, said rims having a thickness materially less than the axial height of said pleats, said score lines defining tucks in said inner and outer portions that extend substantially transversely to and out of the plane of the sides in which they are formed, the tucks in the respective adjacent end portions of adjacent pleat sides extending in the same circumferential direction and being nested together, the tucks in the inner end portions extending on one side of the pleat side and the tucks in the outer end portions extending on the opposite side of the pleat side, each pleat side being folded double adjacent the outer edge of each end portion and being disposed in said rims, said rims defining planes that are substantially normal to the axis of the annulus, said score lines comprising a Y-shaped section with the stem of the Y extending to the adjacent edge of the sheet and a straight section extending across the tips of the Y-section, the tips of said Y-section extending to opposite edges of said pleat side.

Claim 5

A filter element for air or the like comprising a sheet of pleated filter material in the form of an annulus with the pleats extending radially of the axis of the annulus and across the full width of the annulus, each pleat comprising two radially extending sides and adjacent pleats having a common side, said sides having inner and outer end portions and the sheet having score lines therein located in said end portions, said end portions being bent and folded about said score lines to form inner and outer mounting rims comprising at least two layers of said sheet in face to face contact with each other, said rims having a thickness materially less than the axial height of said pleats, said score lines defining tucks in said inner and outer portions that extend substantially transversely to and out of the plane of the sides in which they are formed, the tucks in the respective adjacent end portions of adjacent pleat sides extending in the same circumferential direction and being nested together, the tucks in the inner end portions extending on one side of the pleat side and the tucks in the outer end portions extending on the opposite side of the pleat side, each pleat side being folded double adjacent the outer edge of each end portion and being disposed in said rims, said rims defining planes that are substantially normal to the axis of the annulus, said score lines comprising a Y-shaped section with the stem of the Y extending to the adjacent edge of the sheet and a straight section extending across the tips of the Y-section, the tips of said Y-section extending to opposite edges of said pleat side.

Claim 6

A filter as set forth in claim 3 including resilient annular sealing members encasing said rims.

Claim 7

A blank for forming a pleated filter element comprising an elongated strip of filter material having opposite faces and parallel longitudinal side edges, a series of pleat score lines formed in a face of said strip and extending parallel to each other and normal to said edges and across the entire strip and serving as hinge lines for the apices of pleats to be formed in the strip, and tuck score lines formed in a face of the strip between each pair of pleat score lines and adjacent each longitudinal edge of the strip and extending to and intersecting said edge at their outer ends and said pleat score lines at their inner ends, said tuck score lines each including a V-section located between adjacent pleat score lines with the tips of the V pointing toward the center of the strip, said tuck score lines also each including a stem score line located between adjacent pleat score lines and extending outwardly from the apex of the V and intersecting the adjacent side edge, said stem score lines forming with said V-sections a series of Y-shaped tuck score lines.

Claim 8

A blank for forming a pleated filter element comprising an elongated strip of filter material having opposite faces and parallel longitudinal side edges, a series of pleat score lines formed in a face of said strip and extending parallel to each other and normal to said edges and across the entire strip and serving as hinge lines for the apices of pleats to be formed in the strip, and tuck score lines formed in a face of the strip between each pair of pleat score lines and adjacent each longitudinal edge of the strip and extending to and intersecting said edge at their outer ends and said pleat score lines at their inner ends, said tuck score lines each including a V-section located between adjacent pleat score lines with the tips of the V pointing toward the center of the strip, said tuck score lines also each including a stem score line located between adjacent pleat score lines and extending outwardly from the apex of the V and intersecting the adjacent side edge, said stem score lines forming with said V-sections a series of Y-shaped tuck score lines.

Claim 9

A blank as set forth in claim 5 wherein said blank is adapted to be turned into an annulus and the Y score lines on the inner periphery of the annulus are longer than those on the outer periphery of the annulus.