Patent ID: 8061529

Claim:
A filter cartridge comprising: a rigid hollow moulded outer body; and a filter element comprising a paper roll having an axial core having a central axis and an outer periphery having an inlet end and an outlet end and being held in the outer body such that liquid passes axially through the paper roll and radially through a spacer means adjacent the outlet end, the spacer means defining part of a return flow passage, wherein the hollow outer body has an open inlet end and a continuous axially extending cylindrical side wall having an inside diameter and surrounding the outer periphery of the paper roll, the hollow outer body having ribs projecting inwardly from the cylindrical side wall, the spacer means comprises an axially extending screen support member and a screen supported on the screen support member, the screen comprising a flat apertured disc having a grid of apertures between an inner ring and an outer ring, the inner ring and the outer ring comprising non-apertured annular margins of the screen and being disposed between the filter element and the screen support member with the filter element positioned on the screen for flow of filtrate from the filter element through the screen into the spacer means, the screen support extending radially from the axial core and comprising an outer ring and an inner ring adjacent the axial core and being segmented by circumferentially spaced radial connectors extending between the inner ring and the outer ring and having spaces between the connectors, the screen being seated on the connectors, the inner ring having apertures communicating with the axial core, and the return flow passage comprising the screen, the spaces between the connectors and the apertures in the inner ring, the outer ring having an outside diameter approximately equal to the inside diameter of the side wall, and the outer ring of the screen having an outside diameter approximately equal to the outside diameter of the outer ring of the screen support member so that the respective inner and outer rings of the screen and the screen support member overlap.