Patent ID: 7694754

Claim:
An earth boring bit, comprising: a bit body having a depending bearing pin; a cone having a cavity rotatably mounted on the bearing pin; a seal groove formed in the cavity of the cone, the seal groove having two side walls and a base; an elastomeric seal ring having an inner diameter surface, an outer diameter surface and inboard and outboard side surfaces, the inboard side surface being in contact with lubricant in the cavity of the cone, the outboard side surface adapted to be in contact with drilling fluid, the outer diameter surface being in sealing engagement with the base of the groove, the inner diameter surface protruding from the groove and in sealing engagement with the bearing pin; at least one protuberance protruding from at least one of the side surfaces of the seal ring for contact with one of the side walls of the groove; wherein the side surface of the seal ring containing the protuberance has a communication path between the outer diameter surface and the inner diameter surface, enabling communication of fluid between the outer diameter surface and the inner diameter surface on the side surface containing the protuberance; and wherein there are no other sealing members between the cone and the bearing pin farther inboard of the inboard side surface of the seal ring.