Patent ID: 7160451

Claim:
A liquid filter assembly comprising: (a) an outer housing having a bottom and a side wall and defining an interior; (b) a top plate including a plurality of liquid flow entry apertures and a threaded exit aperture; (c) a filter cartridge positioned within the housing interior; the filter cartridge comprising media extending between first and second end caps; (i) the media defining and surrounding an open center; (ii) the first end cap having an open central aperture; and, (iii) the second end cap being a closed end cap; (d) an internally received treatment agent storage and release cartridge having a ring shape and positioned within the housing interior between the filter cartridge and the top plate; (i) the treatment agent storage and release cartridge including an outer wall, an inner wall and an end wall; (ii) the inner wall surrounding and defining a central flow channel around which the treatment agent storage and release cartridge is positioned, as a ring; (iii) the treatment agent storage and release cartridge being positioned with the central flow channel in exit flow communication with the open center defined by the media; (iv) the inner wall around the central flow channel having no diffusion apertures therein; (v) the end wall having a diffusion aperture arrangement of at least one diffusion aperture therethrough; and (vi) the outer wall having diffusion apertures therethrough; and (e) a first gasket positioned between the treatment agent storage and release cartridge and the top plate at a location between the liquid flow entry apertures and the top plate threaded exit aperture; (f) the treatment agent storage and release cartridge being positioned: (i) with the end wall of the storage and release cartridge directed toward the top plate; and (ii) with all diffusion apertures in the treatment agent storage and release cartridge only providing flow communication between an interior of the treatment agent storage and release cartridge and a region exterior to the treatment agent storage and release cartridge, on an opposite side of the first gasket from the threaded exit aperture, and into a region between the first gasket and the outer housing side wall.