Patent ID: 6911143

Claim:
A filter assembly comprising: a filter cartridge comprising: a filter element extending between axially separated first and second ends; a housing end cap defining a portion of a cylindrical space and supporting the first end of the filter element, said housing end cap having a first end defining an axial opening, a generally cylindrical 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 said roll seam is radially spaced from the side wall of the housing end cap to define an annular space, said annular space comprising portions having first and second radial widths relative to the side wall, said first radial width being smaller than said second radial width; 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 defining a generally cylindrical receptacle, said wall having inside and outside surfaces and terminating in a lip, said outside surface including outwardly projecting first engagement structures, said lip configured for axial reception into said annular space and including a plurality of outwardly projecting keys corresponding to those portions of the annular space of said second radial width; and a hoop-like 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 is axially received in said base with said housing end cap axially received in said receptacle, said lip axially penetrating said annular space 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 retain the cartridge to the base in a substantially fixed axial and rotational relationship.