Abstract: One aspect of the invention is a roller cone drill bit including a bit body having three legs depending therefrom, each leg having a journal, a roller cone rotatably mounted on each journal, and each roller cone having a plurality of cutting elements thereon. The cutting elements are arranged in rows on each cone. The rows include at least a gage row and a first row interior of the gage row. The first interior row is staggered with respect to the gage row on each of the three cones. Another aspect of the invention is a roller cone drill bit including a bit body having three legs depending therefrom. Each leg has a journal, a roller cone rotatably mounted on each journal, and each roller cone has a plurality of cutting elements thereon. The cutting elements are arranged in rows on each cone. The rows include at least a gage row and a first row interior of the gage row. The first interior row is staggered with respect to the gage row on at least two of the three cones.

Abstract: A cutter element for a drill bit has a non-rectilinear crest. The cutter element has a base portion and an extending portion and the extending portion has either a zero draft or a negative draft with respect to the base portion. The non-positive draft allows more of the borehole bottom to be scraped using fewer cutter elements. The cutter elements having non-positive draft can be either tungsten carbide inserts or steel teeth.

Abstract: A roller cone drill bit is disclosed which includes at least one roller cone rotatably mounted to a bit body. The bit body includes therein a lubricant reservoir adapted to supply lubricant to bearings on which the roller cone rotates about the bit body. The bit includes a sensor adapted to detect drilling fluid contamination of the lubricant. The bit includes a processor/transmitter operatively coupled to the sensor and adapted to communicate signals corresponding to detected contamination.

Abstract: Enhanced inserts are formed having a cylindrical grip and a protrusion extending from the grip. An ultra hard material layer is bonded on top of the protrusion. The inserts are mounted on a rock bit and contact the earth formations off center. The ultra hard material layer is thickest at a critical zone which encompasses a major portion of the region of contact between the insert and the earth formation. Transition layers may also be formed between the ultra hard material layer and the protrusion so as to reduce the residual stresses formed on the interface between the ultra hard material and the protrusion.

Abstract: A cutter element for use in a drill bit, comprising a substrate and a cutting layer. The substrate comprises a grip portion and an extension portion, where the grip portion has an insert axis and an extension portion including an interface surface having a first apex. The cutting layer is affixed to the interface surface and has a cutting surface having a second apex. The cutting layer is shaped such that when a plane passing through the first apex and lying parallel to the insert axis and normal to a radius from the insert axis, the plane divides the cutting layer into major and minor portions and the major portion has a major volume that is at least 60 percent of the total volume of said cutting layer. Alternative embodiments of the present invention include variations wherein the first and second apices do not coincide and wherein the interface surface of the substrate is not axisymmetric. Using these variations, cutter elements having sizeable variations in thickness are constructed.

Abstract: A cutter element for a drill bit. The cutter element has a base portion and an extending portion and the extending portion has either a zero draft or a negative draft with respect to the base portion. The non-positive draft allows more of the borehole bottom to be scraped using fewer cutter elements. The cutter elements having non-positive draft can be either tungsten carbide inserts or steel teeth.

Abstract: Multi-piece seals of this invention include an annular seal body that is formed from an elastomeric energizing material, and that has a static seal surface along one surface and a contacting surface along another surface. A remaining seal portion in the form of a seal jacket or seal cap is connected to the seal body along the contacting surface to provide a dynamic sealing surface thereto. The seal jacket or cap is formed from a material that is different from the seal body and, more Specifically, from a material that displays improved wear resistance when compared to the seal body. A preferred seal jacket or cap material is a composite construction including a nonelastomeric polymer fabric that is impregnated with an elastomeric material. The seal jacket or cap is configured to connect with the seal body by mechanical attachment means independent of chemical cross-linked bonding. Multi-piece seals of this invention can be formed from two components, e.g.

Abstract: A cutter element for a drill bit. The cutter element has a base portion and an extending portion and the extending portion has either a zero draft or a negative draft with respect to the base portion. The non-positive draft allows more of the borehole bottom to be scraped using fewer cutter elements. The cutter elements having non-positive draft can be either tungsten carbide inserts or steel teeth.

Abstract: A cutter element for a drill bit has a non-rectilinear crest. The cutter element has a base portion and an extending portion and the extending portion has either a zero draft or a negative draft with respect to the base portion. The non-positive draft allows more of the borehole bottom to be scraped using fewer cutter elements. The cutter elements having non-positive draft can be either tungsten carbide inserts or steel teeth.

Abstract: A polycrystalline diamond enhanced insert is disclosed. The insert includes a body portion adapted for attachment to an earth-boring bit and a top portion for contacting an earthen formation. The top portion of the insert is provided with two different compositions of polycrystalline diamond. In the primary surface of the top portion, a tougher or less wear-resistant polycrystalline diamond layer is provided, whereas a more wear-resistant polycrystalline diamond layer is provided in the remaining region of the top portion. In addition to polycrystalline diamond, polycrystalline boron nitride and other superhard materials also may be used.

Abstract: A rolling cone drill bit is provided that has gage inserts on the first row from the bit axis to cut to full gage diameter that have a cutting portion enhanced with a layer of super abrasive material. The gage cutting surface has a center axis that is canted to be more normal to the gage curve such that the its point of contact at gage is away from the thinner portion of the layer of super abrasive material.

Abstract: Superhard material enhanced inserts and methods of making the same have been disclosed. The enhanced insert includes a body portion adapted for attachment to the earth-boring bit and a top portion for contacting an earthen formation to be drilled. The top portion includes a substrate and a layer of superhard material over a portion of the substrate other than in central region of the outer lateral face. For example, a layer of polycrystalline diamond is provided in the leading transition of the top portion, whereas the trailing transition and the central region of the outer lateral face of the top portion are substantially free of polycrystalline diamond.

Abstract: A cutter element for a drill bit. The cutter element has a base portion and an extending portion and the extending portion has either a zero draft or a negative draft with respect to the base portion. The non-positive draft allows more of the borehole bottom to be scraped using fewer cutter elements. The cutter elements having non-positive draft can be either tungsten carbide inserts or steel teeth.

Abstract: Enhanced inserts are formed having a cylindrical grip and a protrusion extending from the grip. An ultra hard material layer is bonded on top of the protrusion. The inserts are mounted on a rock bit and contact the earth formations off center. The ultra hard material layer is thickest at a critical zone which encompasses a major portion of the region of contact between the insert and the earth formation. Transition layers may also be formed between the ultra hard material layer and the protrusion so as to reduce the residual stresses formed on the interface between the ultra hard material and the protrusion.

Abstract: A cutter element for a drill bit. The cutter element has a non-rectilinear crest. The non-rectilinear or curvilinear crest provides an advantageous distribution of the cutting forces across the body of the cutter elements and thus improves bit life. The curvilinear crest also allows the cutter element to more efficiently lift the portion of the formation that is being cut, thereby improving cutting action in certain formations. The cutter elements can have either positive or non-positive draft and can be tungsten carbide inserts.

Abstract: A synthetic diamond cutter is disclosed for rock bits having a diamond cutting face at one end of a body supporting the cutting face. A heel portion is formed by the body near the diamond cutting face. The heel portion forms a groove depression or notch about adjacent to a cutting tip of the diamond cutting face. The cutting tip, as a result of the groove, results in a greater rate of penetration of the diamond cutting face due to a reduction of drag as the cutter works in an earthen formation or against a suitable workpiece.

Abstract: A cutter element having a substantially flat wear face and leading compression and trailing tension zones, wherein the leading compression zone is sharper than the trailing tension zone. Sharpness is defined as either a smaller inside angle at the intersection of a pair of planes or as a smaller radius of curvature. The cutter element of the present invention experiences reduced stress on its trailing portion in the direction of cutting movement and therefore is less subject to extreme impact damage and cyclic fatigue. The present invention can be applied with particular advantage to heel row cutters, but can also be applied to cutters in other rows that primarily ream the borehole wall and cooperatively cut the borehole corner. The present cutter element can be constructed so as to have either a positive or negative rake angle at its leading compression zone, or to have any of a variety of shapes, depending on the characteristics of the formation in which it is to be used.

Abstract: A rotary cone bit for drilling bore holes in earth formations whose body has a thread pin end and a dome end from which extend three legs. A cutter cone is rotatably mounted to each leg and is radially oriented about the bit's central axis. Each cutter cone has a gage row of cutting elements extending from the cone surface nearest the mouth and a nose row extending nearest the cone's apex. A center jet for emitting fluid or mud is located on the dome. The jet has a converging nozzle with an exit orifice which extends below a predefined horizontal plane intersected by the cones or cutting elements. The exit orifice has a constant diameter for a length at least equal to its diameter for reducing the diffusion of the fluid or mud flow emitted. Fluid or mud emitted from the center jet travels substantially uninterrupted within a cylindrical space between the cones which is not invaded by any cutting element.

Abstract: A cutter element having a substantially flat wear face and leading and trailing sections, wherein the leading section is sharper than the trailing section. Sharpness is defined as either a smaller inside angle at the intersection of a pair of planes or as a smaller radius of curvature. The insert of the present invention experiences reduced stress on its trailing portion and therefore is less subject to extreme wear and failure. The present invention can be applied with particular advantage to heel row cutters, but can also be applied to cutters in other rows that primarily ream the borehole wall. The present cutter element can be constructed so as to have either a positive or negative rake angle at its leading section, or to have any of a variety of shapes, depending on the characteristics of the formation in which it is to be used.

Abstract: A chisel insert for rolling cone rock bits is disclosed in which the crest of the insert has a "dog bone" shape by being rounded with the crest ends flaring out to a larger dimension than the middle thereof. The crest is also convex upwardly along its median line thereby making a shorter moment arm at the ends of the crest.