Abstract: A downhole pressure fluctuating tool having an improved acoustical circuit using a fluid oscillator to generate out-of-phase pressure fluctuations in two output legs, one connected to an acoustical compliance inside the tool and the other connected to an acoustical compliance exterior of the tool in a cavity partially formed by the wall of the well. An acoustical inertance with a pressure node at its midregion connects the two acoustical compliances, and said midregion communicates with the annulus between the body of the tool and the wall of the well to discharge fluid from the body at the pressure node to minimize acoustical losses in the annulus.

Abstract: An earth boring bit with sealed and lubricated bearings and rotatable cutters, the seals being isolated from detritus in the borehole by a seal protector ring and groove. The ring, generally L shaped in cross-section, has radial and axial clearances from the registering groove to maintain a labyrinth path with selected values, irrespective of cone movement during drilling.

Abstract: A drilling fluid nozzle for an earth boring bit is formed entirely of tungsten carbide, having hard-ground threads on its exterior for securing in the bit passage. The nozzle has an upwardly facing shoulder located below the threads which sealingly engages a downwardly facing shoulder formed in the bit passage. An O-ring seal is located above the threads.

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: A welding torch is shown with a dual shield gas flow for preventing flux buildup on the weld area for welds in confined spaces. The torch has a wire conduit for receiving an advancing supply of welding wire. The wire conduit has a curved end portion for guiding the welding wire toward the weld area and has an opening through which the welding wire extends for welding. A primary gas conduit directs the flow of primary shield gas and has an open, gas dispensing end adjacent the wire conduit opening. A secondary shield gas source located rearward of the gas dispensing end directs the flow of secondary shield gas in the direction of the weld area. The secondary shield gas flow is arranged to surround the primary gas flow in the direction of the weld. The orientation of the primary gas exiting the primary gas conduit induces the flow of secondary gas to change direction to provide additional gas shielding for the weld area.

Abstract: A method for shanking a rock bit utilizing a shank locator and a cone locator, each with tapered surfaces to engage respectively the tail stock of a lathe and the cones of a rock bit, to accurately align the body and the cones of the bit concentric with the design centerline of the bit. The lathe and cone locators each have interior conical surfaces to assure accurate, coaxial alignment of the shank end and the cone end of the bit. A compensating chuck is used to grip the cone end of the bit body and firmly hold the normally uneven surfaces while the threads are being machined.

Abstract: An earth boring bit has thrust surfaces with enhanced cooling features. The bit has a body with three depending bearing pins. A cutter having an axial cavity is mounted on each bearing pin. The bearing pin and the cavity have mating thrust shoulders. Hard metal inserts or buttons are spaced around each of the shoulders and secured interferingly in mating holes. The buttons in one of the shoulders protrude slightly from the shoulder to allow air to flow past.

Abstract: A tool joint for earth boring drill pipe members has features that increase the amount of torque required to yield the connection. The tool joint has both external and internal make-up shoulders. The pin and box are dimensioned so that the box face contacts the external shoulder while there still is a clearance between the pin face and the internal shoulder. At normal make-up torque, the external shoulder will be tightened to its normal amount. The internal shoulder will tighten to its yield only if additional torque is encountered while drilling. The internal shoulder adds to the amount of torque required to yield the tool joint connection.

Abstract: A method is shown for fabricating cutter elements for a drill bit, each of the cutter elements being mounted on the drill bit by a mounting stud. A plurality of composite compacts are provided, each of the compacts having an exposed abrasive diamond surface bonded to a carbide substrate portion. The exposed diamond surface is coated with a thin, metal layer, which is relatively easier to grind away in subsequent steps than the diamond surface itself. The coated surface of the compact is then ground to a depth slightly less than the depth of the diamond surface to thereby form a smoothly ground surface for the compact. The smoothly ground surface of the compact is then contacted with a heat sink while the composite compact is brazed to the mounting stud. Each mounting stud so prepared is then affixed to a suitable receiving area provided on the drill bit.

Abstract: An earth boring bit having a cantilevered bearing shaft and a compensator system to equalize the pressure of the lubricant with the hydrostatic pressure of the drilling fluid surrounding the bit. A rigid face seal assembly, positioned between the cutter and bearing shaft of the bit, moves axially in response to, and to compensate for, dynamic pressure changes in the lubricant adjacent the seal. This is accomplished by the positioning and sizing of resilient energizer rings in relationship to the geometries of the mating grooves between the cutter and shaft and the rigid sealing rings of the face seal assembly.

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.