Abstract: A fixed cutter drill bit particularly suited for plastic shale drilling includes rows of cutter elements arranged so that the cutting tips of the cutters in a row are disposed at leading and lagging angular positions so as to define a serrated cutting edge. The angular position of the cutting tips of cutters in a given row may be varied by mounting cutters with different degrees of positive and negative backrake along the same blade. Preferably, within a segment of a given row, the cutters alternate between having positive backrake and negative backrake while the cutters mounted with positive backrake are more exposed to the formation material than those mounted with negative backrake. Nozzles are provided with a highly lateral orientation for efficient cleaning. The positive backrake cutter elements have a dual-radiused cutting face and are mounted so as to have a relief angle relative to the formation material.

Abstract: A mold is formed for an building earth boring bit by designing the bit geometry in three dimensions using a computer aided design (CAD) system and then feeding the geometry data of the design to a layering device. The layering device then builds the mold a layer at a time. Materials used in building the mold include, sand, graphite, ceramic, clay, other refractory materials, plastic, rubber and wax. Once the mold is formed, powdered steel or tungsten carbide is poured into the mold and is cured by press molding or infiltrating with a binder forming a bit body. Cutting elements are then inserted in the bit body forming the earth boring bit.

Abstract: Cutting elements for incorporation in a drill bit are provided having a body having an end face interfacing with an ultra hard material cutting layer. A main depression having a nonplanar surface is formed on the substrate and extending to the edge of the substrate subjected to the highest impact loads during drilling. This edge is immediately below the edge of the cutting layer which makes direct contact with the earth formations during drilling. The main depression is formed by forming a plurality of secondary depressions or steps such that depth of the main depression decreases in a radial direction towards the edge of the cutting element. An ultra hard material layer is bonded to the end face of the cutting element body such that the cutting layer is the thickest over the main depression. Consequently, the cutting layer edge making contact with the earth formations during drilling has an increased thickness.

Abstract: A fixed cutter drill bit particularly suited for plastic shale drilling includes rows of cutter elements arranged so that the cutting tips of the cutters in a row are disposed at leading and lagging angular positions so as to define a serrated cutting edge. The angular position of the cutting tips of cutters in a given row may be varied by mounting cutters with different degrees of positive and negative backrake along the same blade. Preferably, within a segment of a given row, the cutters alternate between having positive backrake and negative backrake while the cutters mounted with positive backrake are more exposed to the formation material than those mounted with negative backrake. Nozzles are provided with a highly lateral orientation for efficient cleaning. The positive backrake cutter elements have a dual-radiused cutting face and are mounted so as to have a relief angle relative to the formation material.

Abstract: A steel bodied PCD drag bit is disclosed having a plurality of blades integrally formed thereon, each blade having a bottom surface that includes an angular front section and rear section intersecting to form an apex, the front section having a plurality of sockets formed thereon to receive a plurality of cylindrical cutters elements, the rear section being substantially parallel to the cylindrical cutting.

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: An improved polycrystalline diamond composite ("PDC") cutter comprises a single or a plurality of secondary PDC cutting surfaces in addition to a primary PDC cutting surface. The two cutting surfaces are spaced apart, resulting in enhanced cutter efficiency and useful life. The primary PDC cutting surface is a polycrystalline diamond layer on an exposed end face of the cutter. A secondary cutting surface is formed by a polycrystalline diamond layer embedded within the body of the cutter. The secondary cutting surface can have a larger diameter than the primary cutting surface so that the forward end of the cutter parallels rock formation during drilling and both cutting surfaces engage the rock formation.

Abstract: A rotary drill bit contains a plurality of cutting elements. Each cutting element includes a stud and a cutting disk mounted on the stud. The cutting disk comprises a substrate and a diamond layer bonded to the substrate. The cutting disk comprises a relief formed in an outer peripheral edge of the substrate and diamond layer at a formation-contacting point of the diamond layer, to form a pair of cutting points separated by the relief. The stud includes a channel aligned with the relief for conducting fluid to the relief to cool and clean the cutting points. The stud may include a fluid passage for conducting drilling fluid directly to the channel.

Abstract: A nozzle for a drill bit comprises a nozzle body and a ring for securing the nozzle body in a threaded cavity of the drill bit. The nozzle body includes a fluid passage of the orientable type. The ring comprises an externally threaded sleeve and a cap bonded to a front end thereof. The cap and nozzle body are formed of harder materials than the threaded sleeve. The cap contains dove-tail shaped slots for receiving complementarily shaped projections on a tool to enable the ring to be rotated relative to the nozzle body. By threading the ring into the cavity, the nozzle body can be secured in the cavity with its fluid passage oriented in the desired final orientation.