Cartridge filter with integrated threading having anti-rotation feature

A filter cartridge removably positionable within a cylindrical casing having anti-rotation slots disposed circumferentially around an inside surface of the casing, the filter cartridge comprising:

• a ring of filter media circumscribing a central cavity and having upper and lower ends,
• an upper end cap with a first surface bonded to the upper end of the filter media, and
• a lower end cap with a first surface bonded to the lower end of the filter media, and a ring-shaped member projecting axially downward, away from a second surface of the second end cap, said ring-shaped member having an annular threaded portion whereby a collection bowl with threads can be removably attached to the filter element;
• said ring-shaped member further including flow passages between said threads and said second surface whereby contaminants may pass from a peripheral region of said filter cartridge interiorly of said ring-shaped member and downwardly into the attached collection bowl;
• and said ring-shaped member further including a plurality of anti-rotation keys disposed circumferentially around the annular portion, whereby said anti-rotation keys can mate with the anti-rotation slots on the casing to rotationally fix the filter cartridge with respect to the casing.

A filter subassembly, comprising:

• a cylindrical casing having a radially in-turned lower end with anti-rotation devices disposed circumferentially around an inner surface of the casing toward the lower end,
• a collection bowl for attachment to the lower end of the casing, said collection bowl including a cup-shaped body and an annular threaded portion, and
• a filter cartridge removably disposed within the casing, said filter cartridge including a ring of filter media separating a central cavity from a peripheral cavity in the casing and having upper and lower ends, an upper end cap with a first surface sealingly engaging the upper end of the filter media, and a lower end cap with a first surface sealingly engaging the lower end of the filter media, a ring-shaped member attached to and projecting axially downward, away from a second surface of the second end cap and supported by the in-turned lower end of the casing, said ring-shaped member having an annular threaded portion removably receiving the threads of the collection bowl;
• and said ring-shaped member further including flow passages between said threaded portion and said second surface whereby contaminants may pass from the peripheral cavity interiorly of said ring-shaped member and downwardly into the attached collection bowl;
• and said ring-shaped member further including a plurality of anti-rotation devices disposed circumferentially around the annular portion and projecting radially-outward therefrom, said anti-rotation devices of said ring-shaped member mating with the anti-rotation devices on the casing to rotationally fix the filter cartridge with respect to the casing when the collection bowl is screwed onto the ring-shaped member.

A filter cartridge removably positionable within a cylindrical casing having an anti-rotation device disposed on an inside surface of the casing, the filter cartridge comprising:

• a ring of filter media circumscribing a central cavity and having upper and lower ends,
• an upper end cap with a first surface bonded to the upper end of the filter media, and
• a lower end cap with a first surface bonded to the lower end of the filter media, and a ring-shaped member projecting axially downward, away from a second surface of the second end cap, said ring-shaped member having an annular threaded portion whereby a collection bowl with threads can be removably attached to the filter element;
• said ring-shaped member further including flow passages between said threads and said second surface whereby contaminants may pass from a peripheral region of said filter cartridge interiorly of said ring-shaped member and downwardly into the attached collection bowl;
• and said ring-shaped member further including radially outward projecting key means for cooperating with the anti-rotation device on the casing to rotationally fix the filter cartridge with respect to the casing.