Piston ring spacer-expander with overlap-preventing expander joint

摘要

In a parted corrugated spacer-expander for a piston oil control ring, an improved expander end joint for preventing installation of the expander should overlap occur between the expander ends in which the respective expander ends are each formed in a multiple-bend box-like structure which is self-supporting under stress from the opposing expander end in either the circumferential or the radial direction.