Patent ID: 6863758

Claim:
A method of assembling a filter element, comprising the steps of: forming a plastic filter casing with openings from a flat blank with opposite ends thereof bent towards one another; and joining said opposite ends together by a sealing seam; folding a resilient mat filter into a cylindrical shape, and pushing said mat filter open on a fluid-permeable supporting pipe to surround and engage said supporting pipe, said cylindrical shape of said mat filter having an exterior diameter prior to introduction into said casing larger than an interior diameter of said filter casing along an entire axial length of said mat filter; forming one axial end of said mat filter into a conical shape to facilitate introduction therof into said filter casing; after forming said one axial end into a conical shape, introducing said mat filter and said pipe into said filter casing delimiting a filter chamber; and connecting two end caps to said filter casing; whereby, said mat filter is supported directly on said filter casing and said supporting pipe.