Air filter cartridge

Claim 1

A filter cartridge for filtering air within an enclosed housing which is caused to circulate in a generally toroidal path by rotation of structure within the housing, said cartridge comprising, in combination: (a) a rigid body portion having mating halves initially formed as two separate parts; (b) a first of said parts having a first, flat, annular portion and a first ring portion joined by a plurality of spaced first legs extending integrally between the outer periphery of said first annular portion and said first ring portion; (c) a second of said parts having a second, flat, annular portion and a second ring portion joined by a plurality of spaced second legs extending integrally between the inner periphery of said second annular portion and said second ring portion; (d) said first and second parts being so dimensioned that upon being placed together in mating relation, said first ring portion and said second annular portion present a first pair of essentially continuous, opposing surfaces, and said second ring portion and said first annular portion present a second pair of essentially continuous, opposing surfaces; (e) an annular sheet of filter media engaged about its outer periphery between said first pair of opposing surfaces and about its inner periphery between said second pair of opposing surfaces; and (f) means permanently joining said first and second parts with said media continuously engaged therebetween at both its inner and outer peripheries, whereby air passing between the inside and outside of the annulus formed by said cartridge passes through said media and between said legs of said first and second parts.