摘要 |
<p>An annular spacer-expander spaces and positions two rails in a piston ring groove of a piston for an internal combustion engine. The spacer-expander comprises a plurality of U-shaped members which lie in respective angularly spaced planes including the spacerexpander axis and whose arms open inwardly of the spacer-expander for urging radially inner ends of respective rails into contact with respective radial walls of the piston ring groove. The U-shaped members are interlinked in serpentine fashion to give the spacer-expander circumferential resilience, The ends of the U-shaped members are bent outwardly for urging the rails into contact with an associated cylinder or liner. A plurality of rail spacer lugs are provided for controlling axial movement of the radially outer ends of the rails. Each ring spacer lug is located between a pair of adjacent U-shaped members and is connected to that portion of one of the pair which forms the base of the U.</p> |