Abstract: A filter element, e.g. for an oil filter, which may be annular, is formed from an elongate sheet of paper or paper-like material having elongate side edges, and strips of hot-melt adhesive are applied to extend with one strip of adhesive 10 immediately adjacent one longitudinal side edge and another strip of adhesive similarly immediately adjacent the other elongate side edge of the sheet. The sheet is then folded in concertina fashion, to form an assembly of a plurality of stacked panels 14, which are hinged at folds alternatively on one side and the other of the concertina assembly, whereafter the panels are pressed together whereby alternate pairs of adjacent panels are secured together, and whereby adhesive is squeezed beyond the ends of the secured panels to form beads 16 of adhesive.

Abstract: A centrifugal oil filter in which a cylindrical housing 42 is rotatable by the reaction force from oil jets 56 leaving via nozzles 44, is increased by the provision of ribs 54 on the inner wall surface of the cylindrical housing 28. This enables the cylindrical vessel 42 to be provided with an internal coarse oil filter while allowing an increase in acceleration and rotational speed.

Abstract: An oil filter assembly for an internal combustion engine includes a body (31) which provides inflow and delivery passages and an attachable filter element container (45) which is attached to the body by a screw-thread at its open end to enclose a cylindrical pleated paper filter element (41) which is located by a perforated support tube (35) carried by the main body, the filter element (35) is sealed at one end against the body and is axially positioned by a spring (38) acting between the closed end of the container and a disc-like closure member (42) which thereby maintains engagement between one end of the filter element and the main body and sealing closure of the other end of the filter by the closure member sealing, the radial and axial compression of the filter element being limited by the support tube.

Abstract: A replaceable filter cartridge has a pleated paper filter medium mounted within a frame or casing having a closed side and an open side, the open side being covered by a removable protective tray or lid the internal shape of which has been used in manufacture for moulding a sealing surface onto the periphery of the frame or casing, the closed side of the frame or casing being provided with a perforated portion which is also removable for use of the filter cartridge.