Patent ID: 7306234
Filing Date: 2007-12-11
Classification: F16J

Abstract:
1. Oil wiping ring ( 10 ) for pistons of internal combustion engines, having a closed working surface ( 13 ) that rests against the cylinder wall, as well as an upper and lower ring wall ( 11 a , 11 c ) that run parallel to one another, between which a radial recess ( 12 a ) for accommodating a screw-shaped spring (M), which recess runs over the circumference, is disposed in the center of the ring back ( 12 ), whereby the ring walls ( 11 a , 11 c ) have face surfaces ( 12 b , 12 c ) on the circumference side that are wave-shaped following a sine function towards the ring back ( 12 ), wherein the wave-shaped face surfaces ( 12 b , 12 c ) of the upper and lower ring wall follow a sine function phase-shifted relative to one another and have a wave amplitude that corresponds to at least half the diameter of the screw-shaped spring.