Abstract: An improved rigid face seal that minimizes pressure fluctuations in the lubricant in the vicinity of the seal assembly. The assembly has a first ring with a radial seal face that opposes and engages an opposed radial seal face of a second rigid ring. A first resilient energizer ring is compressed between opposed, generally conical surfaces, one on the first rigid seal ring and the other in a shaft seal groove. The mid-section of the first energizer ring is positioned relative to the journal bearing surface such that its inner periphery is inside the journal bearing surface and thereby defines an essentially constant, lubricant-filled volume between the seal assembly and the shaft seal groove--even as the cutter and seal assembly move relative to the shaft during drilling. A second energizer ring is provided to maintain sealing engagement between the radial seal faces of the first rigid ring and the second rigid ring.

Abstract: An earth boring bit having a rotatable cutter secured to a lubricated, cantilevered bearing shaft, sealed with an improved pressure compensating rigid face seal assembly. The assembly has a rigid ring with a radial face that opposes and engages a radial face integral with a cutter seal groove. A resilient energizer ring is compressed between opposed conical surfaces, one on the rigid ring and the other in a shaft seal groove, to force the radial faces together. The periphery of the energizer ring is inside the journal bearing surface, which is ideally aligned with the mid-section of the ring, to define a essentially constant, lubricant filled, volume between the seal assembly and the shaft seal groove--even as the cutter and seal assembly move relatively to the shaft during drilling. As a result, pressure variations in the vicinity of the seal assembly are minimized.

Abstract: A drill pipe identification system automatically provides an identification number for each drill pipe as the drill pipe is being lowered into or withdrawn from the well. The system has a SAW identification device which is mounted in a cylindrical cavity which is formed within a tool joint of each section of drill pipe. The cavity has an aperture leading to the exterior of the tool joint to allow radio frequency signals to be received and reradiated. The SAW device receives signals from a transmitter and receiver, modulates the signals and reradiates them in a manner that corresponds to an encoded number in the SAW device.

Abstract: A solid head earth boring bit has a central tungsten carbide core sealed at the lower end of a drilling fluid passage that extends through the bit to the face of the bit. The core has a nozzle passage extending through it that is offset from the axis of the drilling fluid passage. The core also has at least one cutting element secured to its face. The cutting elements are secured in holes in the core.

Abstract: An earth boring rock bit having a sealed bearing with air or gas as the circulating medium. An annular groove is formed in the vicinity of the seal and connected to the interior of the bit for cooling the seal and cleaning debris from the area of the seal. An air groove scraper is mounted on the shaft in the exit port of the annular groove to prevent the annular groove from becoming plugged by debris mixing with moisture in the hole.

Abstract: A stabilizer for attachment to drill string in large diameter earth boring or shaft drilling to center the drill string and maintain alignment of the drill bit. The stabilizer has an inner hub that is rigidly secured to the drill string above the bit. A rubber tube inside the inner hub is compressed to lock the inner hub to the drill string. An outer hub encircles the inner hub. A bearing is mounted between the inner hub and outer hub to allow rotation with respect to each other. The bearing includes a frusto-conical ring in contact with individual pads that are exposed to the drilling fluid. A number of arms extend radially outward from the outer hub to centralize the drill string. The arms are telescopingly received in the outer hub and are pinned together by tie bars at their outer ends to allow them to be quickly removed.

Abstract: A shaft drilling machine generally includes a pivotable power swivel supported on a drilling assembly moved along a mast by hydraulic cylinders. Improved means for positioning the mast include a screw jack assembly with one end adapted to be secured to the power swivel and the other end secured to the base of the machine.