Abstract: A self supported cylindrical corrugated filter. The corrugations of the filter define a first and second end. Two arcuate side walls join the first and second end. The filter has a substantially planar front surface and a substantially planar rear surface. The front and rear surfaces extend the length of the filter. The arcuate side walls have a plurality of overlapping folded flaps. Each one of the plurality of flaps is joined to at least one adjacent flap from the plurality of flaps to form the self supported filter.

Abstract: A filter device including a separable housing and cannister-like means, with the improved filter element retained in the latter. The filter element being an elongated tapered strip having a predetermined transverse dimension at its midsection generally equivalent to the diametral measurement of the interior of said cannister and the initial configuration of the tapered sides being equated to the various chordal dimensions of the interior of the cannister-like means integrated with the folds of the filter element, thereby providing a filter element of controllable increased filtration area.