Patent ID: 7413037

Claim:
An earth boring drill bit comprising: a bit body with one bit leg; the bit leg having a bearing pin; a cone rotatably mounted over the bearing pin; the cone having a rearward facing seal surface that rotates with the cone; a rigid seal ring having a forward facing seal surface that engages the rearward facing surface in sliding engagement to form a seal; an elastomeric energizer ring squeezed between an outer diameter portion of the bearing pin and the rigid seal ring to bias the rigid seal ring forwardly; an elastomeric secondary seal ring having a rearward side in contact with a portion of the bit leg, an outer portion of a forward side in contact with a rearward end of the rigid seal ring, and an inner portion of the forward side in contact with the elastomeric energizer ring; a forward extending protrusion between the inner portion and the outer portion of the forward side of the elastomeric secondary seal ring, the forward extending protrusion filling substantially all of a void between the rigid seal ring and the elastomeric energizer ring; and wherein any remaining portions of the void are free of any filler oil.