Oil ring design

A piston ring assembly including two ring elements and a spacer-expander element which spaces apart the ring elements and resiliently loads them in a radially-outward direction, the spacer-expander element having its free ends in abutment and including a series of interconnected parts, short circumferential connecting means at the radially outer periphery of said spacer-expander element to interconnect adjacent parts, each part comprising two spaced-apart pairs of limbs bent inwardly through nearly a right angle from said connecting means, the limbs of each pair being connected only at their inner ends, the inner ends of said limbs being interconnected by respective spaced-apart portions which extend circumferentially and axially of the element, and the respective spaced-apart portions being in contact with and resiliently outwardly loading the ring elements, the spacer-expander element including at the outer periphery thereof a spacer element between the two pairs of limbs of each said part, said spacer element being connected to the center of said part and extending transversely to space apart said ring elements at the outer periphery of the spacer-expander element.