Oil filter and seal means therefor

Claim 1

A screw-in throw-away oil filter having a casing, the casing having an open end and a closed end, an end wall closing the open end, a filter media in the casing, the filter being adapted to be attached by screw threads to a mounting plate on an engine block, the end wall having screw threads thereon for the attachment, inflow and outflow openings in the end wall, the filter media being between the inflow and outflow openings, the end wall having an outer peripheral portion attached to the open end of the casing closing the open end, an inwardly extending short planar portion inwardly of the peripheral portion, a frustoconical portion inwardly of the planar portion and extending inwardly and downwardly from the planar portion, the frustoconical portion having an inner edge, the inner edge being folded back upon the frusto-conical portion a part of the depth of the frusto-conical portion, a second planar portion extending inwardly from the folded back portion, the second planar portion extending toward and ending at an inner periphery of the end plate, a downwardly extending rib intermediate the ends of the second planar portion, the folded back part of the inner edge of the frusto-conical portion, the second planar portion to the rib and the rib forming a pocket intermediate the inner and outer peripheries of the end wall, the folded back part forming an upwardly and outwardly extending wall, the second planar portion forming a straight inner wall and the rib denoting the inner extent of the pocket, a seal ring in the pocket, the seal ring being of a shape to fit into the pocket and comprising upper and lower planar surfaces parallel to each other, an inner planar surface, the joint between the upper planar surface and the inner planar surface engaging the rib in the second planar portion of the end wall, an outer surface being complementary to the frustoconical portion of the end wall with the joint between the outer surface and the upper surface engaging the joint between the folded back portion and the second planar portion of the end wall, whereby when the filter is applied to the mounting plate the seal ring is forced into tight sealing engagement by the compression applied to the lower planar surface of the ring forcing the upper and complementary surfaces into engagement with the respective portions of the wall and the ring is forced into further tight sealing engagement by the pressure of the oil upon the inner planar surface causing the complementary surface into further engagement with the folded back portion of the end wall.