Patent ID: 6881334

Claim:
A filter assembly comprising: a filter cartridge comprising: a filter element extending between axially separated first and second ends; a housing end cap surrounding the first end of the fitter element, said housing end cap having a first end defining an axial opening, a side wall extending from the first end to a second end including a U-shaped bend; and a housing second section defining a portion of the cylindrical space, said housing second section having a first end joined to the housing end cap second end by a roll seam, the second end of the housing second section surrounding the second end of the filter element, wherein the side wall of said end cap tapers radially outwardly from a first diameter at the first end to a larger second diameter at the second end in at least one location; and a base for mounting said filter cartridge to filter a flow of fluid delivered to and retrieved from said filter cartridge through said base, said base comprising: a receptacle wall having an inside surface defining a generally cylindrical receptacle with a third diameter and an outside surface including outwardly projecting first engagement structures, said third diameter being larger than said first diameter but smaller than said second diameter; and a hoop-shaped collar having a first end configured to pass over said cartridge second section, an interior surface including inwardly projecting second engagement structures complementary to said first engagement structures, and a second end including an inwardly projecting annular shoulder engagable against the radially projecting roll seam of the filter cartridge, wherein said cartridge housing end cap is axially received in said receptacle with radial interference between the inside surface of the receptacle wall and the side wall of the end cap, and said collar is axially installed over said cartridge second section bringing said shoulder to bear axially against said roll seam and said collar is rotated relative to said base and cartridge whereby said second engagement structures mate with said first engagement structures to releasably axially retain the cartridge to the base in a substantially fixed axial and rotational relationship.