Air filter device

An air filter device which comprises:

• a top closure member;
• an axially aligned open base larger in diameter than said top closure member;
• frusto conical filter media extending between said top closure member and said base, said filter media having an axis aligned with said top closure member and said base;
• a plurality of circumferential pleats in said filter media, each said pleat having an interior edge and an exterior edge, said interior edges having a greater angle to said axis than the angle to said axis of said exterior edges;
• and
• an axially aligned inverted closed cone extending from said top closure member towards said base.

An air filter device which comprises:

• a top closure member;
• an axially aligned open base larger in diameter than said top closure member;
• a frusto conical filter having a plurality of circumferential first pleats extending between said top closure member and said base and a plurality of circumferential second pleats interspaced between said first pleats having a smaller radial depth than said first pleats;
• and
• an axially aligned inverted cone extending from said top closure member toward said base.

An air filter device which comprises:

• a top closure member;
• an axially aligned open base;
• a plurality of circumferential primary pleats extending between said top closure member and said base wherein each said primary pleat has an outside edge and an inside edge;
• an inverted pleat in each said outside edge;
• an inverted pleat in each said inside edge;
• and
• an axially aligned closed inverted cone extending from said top closure member towards said base.

For use in a filter housing a filter member comprising:

• an annular filter element made of thin filter material folded in a manner to define a series of circumferentially arranged and axially extending pleats, the element having an upstream end and a downstream end, the pleats defining axially extending interior and exterior channels, the pleats having radial inner and outer edges, the filter element being frusto conical in configuration tapering from a larger diameter annular downstream end to a smaller diameter annular upstream end and having a hollow interior;
• means sealing said filter element interior channels at said upstream end;
• means sealing said filter element exterior channels at said downstream end;
• an inverted closed conical member positioned in and closing said annular upstream end, the conical member extending into said filter element hollow interior in the direction towards said downstream end.