Fluid filter

A fluid filter apparatus for removing foreign material such as for instance dust from a fluid medium by forcing the fluid medium through a filter material, said apparatus comprising drum support means (4, 7a) a drum (7) having a circumferential surface and mounted on said drum support means for rotation about the drum axis, a continuous filter material web (8) wound about the circumferential surface of said drum (7) in a plurality of layers and having a free outer end, means (15) coupled to the filter apparatus and in flow communication with the drum for forcing a fluid medium having a foreign material therein through the plurality of layers on said drum with said fluid medium passing from the outermost layer through the successive layers whereby the foreign material is primarily deposited on the outermost layer and a clean fluid is removed from the interior of the drum, a collector shaft (9) rotatably mounted substantially parallel to the axis of the drum, means connecting the free outer end of said web to said collector shaft (9), and means for actuating said collector shaft to wind the outermost layer of said filter material web (8) from said drum to the collector shaft as the contamination of the layer proceeds.