Abstract: An air-cooled earth-boring drill bit including a plurality of lugs. Each lug includes a pin flange. A first roller race is distal to the pin flange. A thrust flange is distal to the first roller race. At least one pin flange vent slot is arranged in a surface of the pin flange opposite the first roller race. The at least one pin flange vent slot opens in a direction of a load side of a bearing. At least one thrust flange vent slot is arranged in a surface of the thrust flange facing the first rollers. The at least one thrust flange vent slot opens in the direction of the load side of the bearing. A plurality of flow passages are arranged within the lug to supply fluid to the at least one pin flange vent slot and the at least one thrust flange vent slot.

Abstract: An air-cooled earth-boring drill bit including a plurality of lugs. Each lug includes a pin flange. A first roller race is distal to the pin flange. A thrust flange is distal to the first roller race. At least one pin flange vent slot is arranged in a surface of the pin flange opposite the first roller race. The at least one pin flange vent slot opens in a direction of a load side of a bearing. At least one thrust flange vent slot is arranged in a surface of the thrust flange facing the first rollers. The at least one thrust flange vent slot opens in the direction of the load side of the bearing. A plurality of flow passages are arranged within the lug to supply fluid to the at least one pin flange vent slot and the at least one thrust flange vent slot.

Abstract: An asymmetric insert has a formation contacting crest thereby decreasing the loading on the insert and increasing the lifetime of the cutter. The insert has a shape prior to assembly in the cutter that includes a base integrally joined to an asymmetric head. The base is mounted in a socket in the cutter body. The head projects from the surface of the cutter and includes a crest positioned to contact the formations with substantially its entire length.

Abstract: Drill cuttings are effectively removed from the bottom of a bore before they can adversely affect the operation of the bit. The bit includes a body member rotatably supporting individual cutter members. A shield means projects from the body member proximate the cutter members. A first portion of the shield means has an outside diameter substantially equal to the outside diameter of the cutter means and substantially equal to the diameter of the bore and a second portion having an outside diameter substantially less than the outside diameter of the cutter members and substantially less than the diameter of the bore. A first passage extending through the bit is adapted to provide communication with a vacuum source to assist in removing the drill cuttings. A second passage extending through the bit is adapted to provide communication with a gas pressure source to assist in removing the drill cuttings.