Spacer expander for piston rings

Abstract

A spacer expander adapted for use in an oil ring assembly of an internal combustion engine comprising a split annular shaped spring body containing a plurality of lugs extending axially from the body to bear on a single rail or double side rails, the body having a sufficiently thick cross-section to exert a radial expansive force on the side rail and cause it to follow the inner surface of the engine cylinder even if the cylinder is distorted at high speed running. The lug is thinner in thickness at least at its root portion than the body and is elastically bendable without affecting the body. Upon inclination of the piston to the cylinder, the side rail is inwardly biased by the cylinder to push a part of the lugs. However, the lugs can elastically bend independently from the body and from the other part of the lugs with the result that the outer radial face of the side rail is always maintained in operative contact with the inner surface of the cylinder.

Dependencies are inferred from the claim text.