Abstract: As exemplified by an automobile engine oil filter, the usual pleated filter paper is internally supported by an interpleated layer of high tear and tensile strength material which is substantially more flexible than the paper. With the ends of both layers anchored conventionally in the element's end caps rigidly held apart by the usual perforated center tube, the flexible material is subjected to a tensile stress when the paper attempts to move inwardly, the paper being thereby supported against rupturing or pleat tear. The flexible material thus functioning as a back-up layer for the paper, can be pretensioned to provide greater additional resistance to inward movement of the paper.

Abstract: A filter apparatus comprising a container, a plurality of sets of rotatable filter elements disposed in the container, each set comprising first and second circular filter plates of different diameters with one or more holes provided in each plate at predetermined distance from the center thereof, and interleaved with third plates of a smaller diameter than the first and second plates, with the sets disposed in a line and sealed in the container with exits provided aligned with the holes. The sets of filter plates are rotated in the same direction. Unfiltered material is supplied to the container at the top and due to the centrifugal force of the rotating plates, the sludge is separated from the liquid and moved toward the outer peripheries of the plates, and then transferred from one plate to the next plate down the line until the sludge is accumulated toward the end of the line.

Abstract: A filter element for filtering air, other gases and liquids comprises two permeable supporting shells arranged one within the other, and a filter medium filling the space between the shells. The filter medium is formed by a plurality of layers of different filter gauge. The finest filter layer is covered by a coarser filter layer at least on its side which is, in use, towards the inlet for the fluid to be filtered. Preferably the filter medium includes three layers, the middle layer of which is the finest filter consisting of binder-free microfiber fleece and the other two layers are similar coarser filters consisting of binder-free supporting fiber fleece.

Abstract: A filter cartridge for filtering fluids comprising: a cylindrical porous support tube which is permeable to the fluid to be filtered; at least one layer of boro-silicate glass filter paper being wrapped around the cylindrical support; a porous sleeve including a wall having a longitudinal slit therein to allow wrapping of the sleeve around the filter paper; and a zipper affixed to the wall which closes the slit and maintains the position of the glass filter paper without damage to the paper. Also disclosed is a method for manufacturing a filter cartridge having as a principle filtering element a boro-silicate glass paper which is very fragile and can be seriously degraded by crushing. The method comprises wrapping at least one layer of boro-silicate glass paper around a cylindrical porous support; wrapping a cylindrical porous sleeve including a wall having a longitudinal slit therein around the filter paper to secure and protect the filter paper; and closing the slit by closing a zipper attached to the wall.

Abstract: Disclosed is a filter medium for removing contaminants, including gels, from molten polymers. The medium contains layers of sintered metal fibers having diameters of 50 microns or less. At least two adjacent layers are separated by a screen, and the screen and layers are bonded together by compression and sintering. Preferably the layers include from 35 to 60 volume percent fibers. The filter medium is graded so that the polymer as it flows through the medium encounters fiber layers having pores that generally decrease in size. The screen has pores that are larger than the average size of the pores in any downstream layer and that are larger than the average size of the pores in the upstream layer immediately adjacent the screen. The screen collects at least some of the gels or other particles that pass through the upstream layer, giving the medium a higher dirt holding capacity than the conventional filter medium.

Abstract: A one-piece molded fluid filter for a fluid dispenser dip tube includes two circular plate portions, at least one having radially extending ribs which define a plurality of fluid passages between the plates. A tubular portion, extending coaxially from the upper of the plates, is adapted for engaging the dip tube and providing communication between the dip tube and the passages. A member extending coaxially from the lower of the plates is provided for insertion into the tubular portion to pressurely engage the tubular portion to maintain the plates adjacent one another. The plates are connected along portions of their circumferences by an integral hinge and may be pivoted with respect to one another about the hinge to expose the ribs for cleaning.

Abstract: An oil filter cartridge comprising filter discs and separator discs stacked alternately, the separator discs having inlet and outlet chambers walled in by the contiguous filter discs. The filter discs have inlet ports in registration with the inlet chambers for introducing unfiltered oil therein. The separator discs are provided with slots registering with the inlet ports of the filter discs. These slots, in combination with the adjacent inlet ports, provide enlarged inlet orifices which are not readily blocked by swelling of the material of the separator discs due to water-contaminated oil.

Abstract: An improved filter of the cartridge type having concentric inner and outer filter elements is disclosed. The elements are formed of non-woven polypropylene fibers. In a preferred embodiment the outer element is formed of a laminate including a supporting layer of a continuous filament and a filtering layer of randomly oriented polypropylene fibers. The outer element is pleated and the space between the elements is filled with particulate, activated charcoal. The axial ends of the filter components are encapsulated in plastisol end caps to secure them together, and to form a sealable working surface to be engaged by the filter housing.

Abstract: A media for filtering blood consisting of a layer of fibers having a thickness of at least 0.015 inches. The fibers in the layer are interlocked with one another by frictional entanglement and the layer may have a larger pore opening size on one surface than on the opposite surface.

Abstract: The invention relates to a device for assembling stacked annular filtering elements under constant pressure. The device comprises a support which provides an abutment for one end of the stack of filtering elements, a presser member which provides an abutment for the other end of the stack, and a calibrated spring which biases the presser member towards the support while trapping the stack of elements between the two abutments. The device is useful for the manufacture of filters used particularly for the filtration of oils.

Abstract: A multiple phase filter cartridge is presented wherein the filter has two or more distinctly different fibrous layers with at least one of the fibrous layers containing active particles. The different layers are formed in place on the filter by a wet accretion process.