One-piece molded filter

A one-piece injection molded plastic fluid filter including a base portion having a fluid passageway therethrough, a head portion spaced axially from said base a predetermined distance, a plurality of axially spaced apart annular rings positioned between said base portion and said head portion, each of said rings having a predetermined internal and external diameter, a plurality of arcuately spaced axially disposed ribs extending between said base and head portions and extending solely in a direction radially inwardly from an internal juncture of the radially outer edges of said ribs with the predetermined internal diameter of each of said rings, said ribs and said annular rings each projecting in radially opposite directions from said junctions and cooperating to provide a multiplicity of predetermined size filtration openings at said juncture between said spaced ribs and rings, said rings have a substantially uniform cross-section and are substantially uniformly spaced from each other and said ribs have inwardly converging side surfaces for providing said openings with a substantially uniform size and shape, and at least one axially disposed larger rib extending between said head and base portions and extending radially outwardly from said juncture, said larger rib having a greater circumferential thickness than the other said ribs integrally connecting each adjacent ring throughout the entire radial extent between said predetermined internal and external diameters for a limited portion of their circumferential extent, whereby said larger rib serves to rigidify said filter rings and serves as a conduit for the injection molded plastic to ensure completed rings.