.~ Piston has lubricant retaining or conducting means {2}
159
.~.~ Pocket or chamber
DEFINITION
Classification: 92/159
(under subclass 158) Apparatus in which said means includes a cavity, trough, or other means which forms a part of the piston and acts as a reservoir for the lubricant.
(1) Note. A mere radially directed circumferential oil retaining groove on the piston side wall portion having the open side closed by the relatively movable cylinder wall is excluded. Included is a circumferential groove having a configuration which permits the retention of oil therein independently of the cooperating cylinder wall, or a ported trough or chamber on a piston portion or generally any receptacle means on the piston capable of trapping or collecting lubricant for holding such lubricant or directing the same to some specified outlet in said receptacle means.
