Abstract: Dual functioning seals for use in forming a lubricant seal in a rotary rock bit comprise an annular elastomeric seal body having a dynamic seal surface for sealing against a dynamic surface and a static seal surface for sealing against a static surface. The seal body has an asymmetric axial cross-sectional geometry the dynamic seal surface having a greater radius of curvature than that of the static seal surface. The dynamic and static seal surfaces are formed from different elastomeric materials, and the dynamic seal surface is formed from an elastomeric material that is harder and more wear resistant than the elastomeric material used to form the static seal surface. A rotary rock bit seal constructed in this manner is well adapted to accommodate the different operating conditions and sealing requirements that exist both at the dynamic and static surfaces of the seal to ensure optimal seal performance and, thereby enhance the service life of the rock bit.

Abstract: Dual functioning seals for use in forming a lubricant seal in a rotary rock bit comprise an annular elastomeric seal body having a dynamic seal surface for sealing against a dynamic surface and a static seal surface for sealing against a static surface. The seal body has an asymmetric axial cross-sectional geometry the dynamic seal surface having a greater radius of curvature than that of the static seal surface. The dynamic and static seal surfaces are formed from different elastomeric materials, and the dynamic seal surface is formed from an elastomeric material that is harder and more wear resistant than the elastomeric material used to form the static seal surface. A rotary rock bit seal constructed in this manner is well adapted to accommodate the different operating conditions and sealing requirements that exist both at the dynamic and static surfaces of the seal to ensure optimal seal performance and, thereby enhance the service life of the rock bit.

Abstract: A high performance rock bit journal seal is formed from a composite material comprising an elastomeric material and a nonelastomeric polymeric material. The polymeric material is preferably in the form of fibers compiled or woven into a sheet. The elastomeric material may include one or more lubricant additives. The composite seal material comprises a number of repeating sheets of polymeric fabric that are bonded together with the elastomeric material. The seal can either be formed entirely of the composite seal material or partially of the composite material, in which case it is preferred that the seal wear or dynamic surface be formed from the composite material and the remaining portion of the seal be formed from an elastomeric material. The seal can be used as a primary journal seal, or as a secondary journal seal in a dual seal bit.

Abstract: A new hardfacing composition is disclosed. In addition, a pulsed plasma transferred arc method for depositing hardfacing material with a higher content of carbide and lower dilution by a substrate metal is disclosed. The disclosed method produces a hardfacing coating which has a strong metallurgical bond to the substrate metal. The method includesthe following steps: (1) establishing a transferred plasma arc between an electrode and an area of a work piece, (2) optionally preheating the work piece to at least 250.degree. F., (3) forming a plasma column of inert gas in the arc by passing an electrical current between the electrode and the work piece, (4) feeding a stream of hardfacing material in powder form into the plasma column, and (5) pulsing the current between a pre-selected high pulse current value and low pulse current value while feeding the powdered hardfacing material.

Abstract: A metal-matrix diamond or cubic boron nitride composite and method of making the same are disclosed. The metal-matrix/diamond composite includes grains of diamond uniformly distributed in a metal matrix. Alternatively, grains of cubic boron nitride may be used. Suitable metals for the metal matrix material may include nickel, cobalt, iron, and mixtures or alloys thereof. Other transition metals also may be used. The metal-matrix/diamond or metal-matrix/cubic boron nitride composite has high fracture toughness due to its fine microstructure. Such a metal-matrix/diamond or metal-matrix/cubic boron nitride composite is suitable for use in blanks or cutting elements for cutting tools, drill bits, dressing tools, and wear parts. It also may be used to make wire drawing dies.

Abstract: In one embodiment, composite constructions of the invention are in the form of a plurality of coated fibers bundled together to produce a fibrous composite construction in the form of a rod. Each fiber has a core formed from a hard phase material, that is surrounded by a shell formed from a binder phase material. In another embodiment of the invention, monolithic sheets of the hard phase material and the binder phase material are stacked and arranged to produce a swirled composite in the form of a rod. In still another embodiment of the invention, sheets formed from coated fibers are arranged to produce a swirled composite. Inserts for use in such drilling applications as roller cone rock bits and percussion hammer bits, and shear cutters for use in such drilling applications as drag bits, that are manufactured using conventional methods from these composite constructions exhibit increased fracture toughness due to the continuous binder phase around the hard phase of the composites.

Abstract: A steel tooth particularly suited for use in a rolling cone bit includes a parent metal core having an inner gage facing surface, leading and trailing edges, a root region adjacent to the cone and an outer most edge spaced from the root region. A hardfacing layer that includes at least two hardfacing materials having differing wear characteristics is disposed over the parent metal core in an asymmetric arrangement of regions of the first and second materials. A first of the hardfacing materials has a higher low stress abrasive wear resistance than that of the second material. The second material has a high stress abrasion resistance that is greater than the first material. The first and second materials are applied in generally contiguous regions over the entire gage facing surface of the parent metal core so as to optimize regions of the tooth for the particular cutting duty experience by that region.

Abstract: A milled tooth shaped rotary cone drill bit for drilling oil wells and the like manufactured using a powder metallurgy process in which an alloy powder is pressure molded into the desired bit shape, sintered, and precision machined.

Abstract: A hardfacing material for shirttail and gage surfaces of a rock bit cone and a gage row of rock bit teeth comprises steel in the range of from 20 to 40 percent by weight, and tungsten carbide particles in the range of from 60 to 80 percent by weight which contains single crystal monotungsten carbide particles having a particle size primarily less than about 200 mesh with a preferred average particle size in the range of from 30 to 70 microns. According to further embodiments, carburized tungsten carbide particles and/or spherical cast carbide particles are mixed with the single crystal monotungsten carbide in the hardfacing. The carburized tungsten carbide particles have a particle size in the range of from about 10 to 50 microns. The spherical cast tungsten carbide particles have a particle size in the range of from about 20 to 150 microns. The particle size distributions of the tungsten carbide particles are bimodal or trimodal for improved weldability and wear resistance in the hardfacing.

Abstract: Double cemented carbide composites comprise a plurality of first regions and a second ductile phase that separate the first regions from each other. Each first region comprises a composite of grains and a first ductile phase bonding the grains. The grains are selected from the group of carbides consisting of W, Ti, Mo, Nb, V, Hf, Ta, and Cr carbides. The first ductile phase is selected from the group consisting of Co, Ni, Fe, alloys thereof, and alloys with materials selected from the group consisting of C, B, Cr, Si, and Mn. A preferred first region comprises tungsten carbide grains that are cemented with a cobalt first binder phase and which are in the form of substantially spherical pellets. The second ductile phase is selected from the group consisting of Co, Ni, Fe, W, Mo, Ti, Ta, V, Nb, alloys thereof, and alloys with materials selected from the group consisting of C, B, Cr, and Mn. A preferred second ductile phase is cobalt.

Abstract: Dual functioning seals for use in forming a lubricant seal in a rotary rock bit comprise an annular elastomeric seal body having a dynamic seal surface for sealing against a dynamic surface and a static seal surface for sealing against a static surface. The seal body has an asymmetric axial cross-sectional geometry the dynamic seal surface having a greater radius of curvature than that of the static seal surface. The dynamic and static seal surfaces are formed from different elastomeric materials, and the dynamic seal surface is formed from an elastomeric material that is harder and more wear resistant than the elastomeric material used to form the static seal surface. A rotary rock bit seal constructed in this manner is well adapted to accommodate the different operating conditions and sealing requirements that exist both at the dynamic and static surfaces of the seal to ensure optimal seal performance and, thereby enhance the service life of the rock bit.

Abstract: A high performance rock bit journal seal is formed from a composite material comprising an elastomeric material and a nonelastomeric polymeric material. The polymeric material is preferably in the form of fibers woven into a sheet. The elastomeric material includes at least one lubricant additive. The composite seal material comprises a number of repeating sheets of polymeric fabric that are bonded together with the elastomeric material. In one embodiment, the seal includes a body formed entirely from the composite material, in which case both the static and dynamic seal surfaces are the same. In another embodiment, the seal includes a first body portion formed from the composite material, and a remaining body portion formed from a noncomposite elastomeric seal material.

Abstract: An improved hardfacing for teeth and other surfaces of milled tooth rock bits includes steel in the range of from 20 to 50 percent by weight, and filler in the range of from 50 to 80 percent by weight. The filler includes spherical cast tungsten carbide particles alone or in a mixture of other tungsten carbide particles such as crushed cast spherical or crushed cemented tungsten carbide, macrocrystalline tungsten carbide, or the like. The single crystal monotungsten tungsten carbide particles have a particle size in the range of from 16 to 40 mesh and/or in the range of from 80 to 200 mesh.

Abstract: A PDC drag bit body is disclosed which utilizes a high-strength infiltration binder having a composition comprising a nickel, cobalt, or iron base alloy. The infiltration molding process is modified to account for the higher melting temperatures of these alloys by using graphite plugs in the mold instead of actual PDC inserts, and after the PDC drag bit body has been fabricated and cooled, removing the graphite plugs and brazing the actual PDC inserts in the cavities left by the plugs. Further, the mold is coated with hexagonal-structure boron nitride to prevent the nickel, cobalt, or iron from attacking the graphite molds.

Abstract: A cage type cyclone fine screen device having an overflow pipe (2), a feeding section (3), an undersized section (6), a conical section (7), a cage type screen (5) and an integrated cylindrical section (4). The cage screen is fixed by installing the upper and lower flanges respectively onto the upper end opening of the integrated cylindrical section and the upper end opening of the inner ring of the undersized section, resulting in convenience for assembly and disassembly. The device has the advantages of high processing capability, high classification efficiency, compactness, low investment, low power consumption, and long lifetime of the screen. This device is suitable for grading and concentrating aluminum hydroxide and other fine particles.

Abstract: A cutting tool is decarburized by placing the tool in a protective environment, heating in this environment to a temperature of 600.degree.-1100.degree. C., and maintaining this temperature for a period of 15-120 minutes. The cutting tool may be a cemented carbide microdrill which contains primary cutting edges which form an angular surface on the forward end of a rake surface at the cutting tip, and a radius surface which extends from the angular surface to a flank surface which extends from an outer diameter of the cutting tip to an axis of symmetry of the tool.

Abstract: A drill but having a drill body with a cutting tip, an axis of symmetry, and a plurality of flutes wherein said flutes have a rake surface at said cutting tip. The cutting tip includes a plurality of side blades between said flutes and joined at a web, a plurality of flank surfaces extending from an outer diameter of said cutting tip to said axis of symmetry, and a plurality of primary cutting edges at the intersection of said flank surfaces with said rake surfaces. Both the rake and flank surfaces have extensions which would intersect each other at an intersection. The primary cutting edges include an angular surface formed on the forward end of said rake surfaces which is located such that the length of said extension of said rake surface measured between said angular surface and said intersection is a first predetermined value and the length of said extension of said flank surface measured between said angular surface and said intersection is a second predetermined value.

Abstract: A rock bit grease composition is prepared by combining synthetic polymer lubricant basestocks comprising a first ethylene-alphaolefin polymer having an average molecular weight in the range of from 3,500 to 4,000, and a polyisobutylene polymer to form a first master. A metal complex soap base thickener is prepared by combining a synthetic polymer lubricant basestocks comprising a second ethylene-alphaolefin having an average molecular weight in the range of from 400 to 800, with an alkali-metal or alkaline-earth metal hydroxide, and at least one fatty acid. A preferred fatty acid is a blend of a first fatty acid having in the range of from 15 to 20 carbon atoms, and a second fatty acid having in the range of from 5 to 12 carbon atoms. The first master and metal complex soap base thickener are mixed together in desired proportions.