Abstract: A revised sealing structure for an injection molded filter canister, which is resistant to leaks despite the periodic warping of the lid. A nearly square cross-section groove is placed in the body of the filter around the perimeter of the body open end. Within the groove is placed a "lathe cut" gasket; this is an elastomeric gasket having a precision rectangular cross section. On the lid, centered so as to be positioned opposite the groove in the body, and sized to be nearly centered in the groove, is at least one raised, circular ridge. With the addition of the ridge to the lid, in combination with the lathe cut gasket and the revised groove, that the lid may be easily placed in sealing contact with the body, and that the incidence of leaks is substantially eliminated in reinforced plastic molded filters. No special care or skill is needed of the workman in placing and fastening the lid to the filter body to achieve a tight seal.

Abstract: An apparatus for adapting a paper towel filter to utilize a range of paper towel or filter element sizes. A perforated end plate is provided to engage the ends of the filter element. An inwardly sloped truncated conical extension from the center of the end plate extends into the ends of the filter element roll, which seats along the conical extension, based on its inner diameter. A pipe sealing face is provided along the inner surface of the conical extension, at the end away from the end plate; this face sealingly encloses an axial pipe. The combination of two end plates, so mounted on an axial pipe, and enclosing a paper towel roll, forms a removable filter cartridge for a paper towel filter, which readily adapts to a variety of sizes of paper towel rolls.

Abstract: In a high precision oil filter, a blind engagement of a threaded coupling with a supported shaft can be made without misalignment or cross threading in the coupling by providing, for a male threaded shaft having threads of a designed pitch and peak outer diameter, a mated female coupling having threads of the same pitch and size, and providing within the female coupling a cylindrical throat having an internal diameter equal to the peak outside diameter of the male coupling and a smooth cylindrical surface of a length at least equal to three times the thread pitch and preferably equal to five times the thread pitch.