Piston ring assembly

Claim 1

AN OIL RING ASSEMBLY FOR USE IN A PISTON HAVING AN OIL RING GROOVE WITH AN OIL DRAINAGE OPENING IN ONE FACE THEREOF WITH THE DIMENSION OF SAID OPENING IN THE DIRECTION OF THE CIRCUMFERENCE OF SAID GROOVE BEING LESS THAN THAT OF SAID ONE FACE, SAID RING ASSEMBLY INCLUDING IN COMBINATION AN ANNULAR PARTED RAIL INITIALLY ASSEMBLED IN SAID GROOVE WITH THE PARTING GAP THEREOF LOCATED IN THE CIRCUMFERENTIAL PORTION OF SAID GROOVE HAVING THE LOWEST RATE OF OIL ACCUMULATION, AND EXPANDER-SPACER MEANS DISPOSED IN SAID GROOVE IN OPERATIVE ENGAGEMENT WITH SAID RAIL FOR BIASING SAID RAIL INTO AN OIL SEALING POSITION IN SAID GROOVE, SAID EXPANDER-SPACER MEANS HAVING MEANS PROJECTING THEREFROM INTO SAID OPENING IN SAID GROOVE SO THAT ROTATION OF SAID EXPANDER-SPACER MEANS RELATIVE TO SAID PISTON CAUSES SAID PROJECTING MEANS TO MOVE CIRCUMFERENTIALLY IN SAID OPENING TO THEREBY REDUCE CLOGGING OF SAID OPENING AND SO THAT ROTATION OF SAID EXPANDER-SPACER MEANS IS LIMITED TO SAID DIMENSION OF SAID OPENING IN THE DIRECTION OF THE CIRCUMFERENCE OF SAID GROOVE WHEREBY THE PARTING GAP OF SAID RAIL IS MAINTIANED IN ITS INITIAL ASSEMBLED POSITION WITHIN THE RANGE OF SUCH DIMENSION DURING OPERATION OF THE PISTON TO THEREBY MINIMIZED LEAKAGE OF OIL THROUGH SAID GAP.