Abstract: A three-piece oil control ring includes a pair of radially split, generally flat annular rails which are supported in an axially spaced relationship by an annular spacer-expander. The expander defines alternating, axially symmetrical and generally U-shaped loops or corrugations. Each loop includes a pair of legs joined to a pad. The pad has a stepped configuration in radial cross section and includes a raised, outer, generally flat portion which supports a rail and a lowered central or intermediate portion. Each loop includes an axially extending lug or tab. The central portion is formed with a dimple or depression which provides sufficient material during the forming operation to configure the lug with a circumferentially extending, elongated rail contact surface. The legs of each of the corrugations are substantially vertical, having an angle from vertical within the range of zero to thirteen degrees.

Abstract: A piston having a ring groove therearound has a three part oil control ring in the groove. The ring includes an axially and radially corrugated expander and two flat annular rails retained by the sides of the groove. The radial wall thickness of the rails is no more than 3% of the diameter of the piston; and the radial wall thickness of the expander is no more then 4.7% of the diameter of the piston.

Abstract: The invention relates to a spin-on centrifugal filter or separator for purifying liquid such as oil used in an engine, and to the method of making and assembling the same. The completed separator is in the form of a spin-on cartridge having rotatably mounted therein a jet-actuated, centrifugal separator or rotor. The cartridge, which can conveniently be screw-threaded and thus of the spin-on type, comprises an outer housing or casing within which the rotor is mounted on a perforated hollow shaft depending from a spin-on cover for the cartridge which may be applied to the outer casing or housing after the rotor has been assembled on the hollow shaft. Liquid, e.g., oil, to be treated enters the cartridge from the engine casing, through a screw-threaded opening in the spin-on cover, passes to and through the hollow perforated shaft into the interior of the rotor where the liquid, under pressure, serves to impart centrifugal motion to the rotor, and passes outwardly from the rotor through jet openings therein.