Abstract: A flat seal (32) for a roller cone rock bit (10) is provided. Flat seal (32) includes a ring-shaped metallic spring (80). Metallic spring (80) has an inner face (88) with an annular inner edge (92) for contacting a sealing surface (72) of a cone (18) in a roller cone rock bit (10). Metallic spring (80) also has outer face (86) with an annular outer edge (90) for contacting a sealing surface (70) of a spindle (16) in the roller cone rock bit (10). Metallic spring (80) has a relaxed axial pitch greater than a clearance (76) between sealing surfaces (70) and (72) of cone (18) and spindle (16). Flat seal (32) also includes an annular inner elastomer shroud (84) disposed on inner face (88) of metallic spring (80) such that the annular inner edge (92) is exposed. Flat seal (32) further includes an annular outer elastomer shroud (82) disposed on outer face (86) of metallic spring (80) such that the annular outer edge (90) is exposed.

Abstract: A roller cone rock bit (10) is provided that has a sealing system with double elastomer seals. A first elastomer seal (30) is disposed between a cone (18) having a cavity (24) and a spindle (16). A second elastomer seal (32) is disposed between cone (18) and spindle (16) forming a seal-gap (33). A main lubricant reservoir (49) has a diaphragm (56) disposed between an inner chamber (53) and an outer chamber (60). Inner chamber (53) is in fluid communication with cavity (24), and outer chamber (60) is in fluid communication with external fluids. Cavity (24) and inner chamber (50) are substantially filled with a first lubricant forming a first volume of lubricant. Diaphragm (56) is operable to transmit a pressure of the external fluids to the first volume of lubricant. A seal-gap lubricant reservoir (70) has a diaphragm (78) disposed between an inner chamber (75) and an outer chamber (82).

Abstract: This invention relates to a rotary drill bit having a body with leg members, where each of the leg members has a projecting conical cutter receiving journal. A conical cutter having an axially extending recess open at one end has friction reducing bearings interior to the conical cutter for rotatably mounting the cutter on the journal. A plurality of lubricant carrying conduits interior to the leg members extending into the bearings provides lubricant for the bearings. This invention provides an improved sealing arrangement for preventing an excessive loss of lubricant from the bearings. The conical cutter is adapted with seal receiving grooves at its open end of the recess to receive two seals, with a circumferential seal gap located between the seals. The outer seal is less rigid than the inner seal and when the circumferential seal gap is supplied with lubricant it bleeds past the outer seal to wash away drilling debris.

Abstract: A sealed rotary drill bit has a plurality of leg members, with each leg member having a projecting conical cutter receiving journal. A conical cutter has friction reducing bearings interior to the conical cutter for rotatably mounting the cutter on the respective journal. A sealing arrangement retains lubricant for the bearings. A circumferential porous gas restrictor is positioned concentric with and spaced outwardly from the sealing arrangement to form an annular gas chamber therebetween. Pressurized gas is carried by passageways into the annular gas chamber. The porous gas restrictor, which can be formed of metal particles bonded together, prevents drilling debris from getting past it, but the porosity of the restrictor allows pressurized gas to pass therethrough as a controlled dissipation and wash away drilling debris, thereby shielding the sealing arrangement from debris that might otherwise reach the sealing arrangement.

Abstract: A rotating drill bit (10) includes a leg (12) and journal arm (14) on which is mounted a cone-shaped cutter (16). The cutter (14) rotates on the journal arm (14) by means of an anti-friction bearing including rollers (20) and ball bearings (26). Air is pumped through the journal arm (14) through conduits (30, 32 and 34). Air flows through the passages between rollers (20) and is collected in a cavity (52). The cavity (52) is vented to the borehole through a slot (54) in the trailing edge of the journal arm (14). A very narrow clearance in the order of a few thousandths of an inch is provided for rotational movement between the cone mouth shoulder (36) and last machined surface (40). Cone mouth shoulder (36) completely covers the last machined surface (40) around the entire periphery of the journal arm (14) except for the approximately 45.degree. slot (54) in the trailing edge of the journal arm (14).

Abstract: A rotary drill bit having a body with a projecting journal and a conical cutter having an axially recessed open end for receiving the journal wherein only the upper portion of the open cone mouth in the cavity formed between the cone and the body is shielded from drilled debris intrusion and the circulating air is channeled in the bearing to the bottom portion of the open cone mouth for improved flow pattern through the various bearing segments whereby the incidence of plugging of the bit due to excess formation being forced into the bearing at the gaping open portion of the upper cone mouth is reduced.

Abstract: A rolling cone cutter earth boring bit is provided with a floating seal for sealing the bearings of the bit from the abrasive materials in the borehole and retaining lubricant within the bearing area. At least one cantilevered bearing pin extends from the arm of the bit. A cutter receiving surface is located on the arm. A first shallow annular groove is located in said cutter receiving surface. A rolling cone cutter is adapted to be rotatably mounted on the bearing pin with said rolling cone cutter having a cone mouth. A second shallow annular groove is located within said cone mouth. Bearing and cutter retaining means are located between the bearing pin and the cone cutter. A first seal unit is positioned around the bearing pin between the cutter receiving surface and the rolling cone cutter.

Abstract: A rotary rock bit with passageways for conducting air or other gaseous fluid to cool the bearings and flush cuttings from the borehole includes valve means for controlling the entry of water into the bearings. The stream of air or other gaseous fluid is directed through a valve system that prevents water from reaching the bearings. In one embodiment a truly positive backflow shutoff valving arrangement through both the nozzle and bearing passageways provides a means for more effectively preventing water and cuttings from entering the bearings and bearing passageways of the bit.