Abstract: An apparatus for inserting an expander ring into an inner circumferential groove of a split piston ring includes a first magazine for storing a stack of piston rings; and a second magazine for storing a stack of expander rings. The second magazine has a discharge end and a longitudinal axis coinciding with a longitudinal axis of the expander ring stack. There are further provided a device for displacing a piston ring from the first magazine into axial alignment with the longitudinal axis of the second magazine at the discharge end thereof; a spreader device for radially outwardly spreading the piston ring positioned at the discharge end; and a pusher for pushing an expander ring from the second magazine parallel to the longitudinal axis into the piston ring spread-open by the spreader device.

Abstract: A piston ring assembly has a ring-shaped expander spring composed of an annular body defining an axial direction and presenting a circumferential main bending region and a plurality of resilient tongues extending radially outwardly from the main bending region and adjoined, adjacent the main bending region, by generally axially extending parts of the annular body. The assembly further has a lamina lying, at least in part, on the tongues and is radially supported by the axially extending parts. The main bending region is disposed radially inwardly of the lamina.