Abstract: An earth boring bit has a steel body having at least one leg with a depending bearing pin. A cone having cutting elements is rotatably mounted to the bearing pin. A ball plug weld is on the outer surface of the leg. A layer of hardfacing applied to part of the outer surface of the leg, the hardfacing having carbide particles in a matrix. A corrosion resistant coating containing at least 50% nickel is formed on parts of the outer surface of the leg that are free of the layer of hardfacing both above and below the ball plug weld.

Abstract: The invention disclosed and taught herein is directed to an improved hybrid drill bit having at least two rolling cutters, each rotatable around an axis of rotation, at least one of the rolling cutters having a high pin angle, and at least one fixed blade. The increase in the pin angle can encompass pin angles above 39 degrees to less than 393 degrees. In at least one embodiment, the improved drill bit expands the capabilities of a hybrid bit to allow the rolling cutters to engage a shoulder portion and/or gage portion of the bit profile and assist the fixed blade(s) in these areas.

Abstract: Methods include one or more of robotically positioning a cutting element on an earth-boring tool, using a power-driven device to move a cutting element on an earth-boring tool, and robotically applying a bonding material for attaching a cutting element to an earth-boring tool. Robotic systems are used to robotically position a cutting element on an earth-boring tool. Systems for orienting a cutting element relative to a tool body include a power-driven device for moving a cutting element on or adjacent the tool body. Systems for positioning and orienting a cutting element on an earth-boring tool include such a power-driven device and a robot for carrying a cutting element. Systems for attaching a cutting element to an earth-boring tool include a robot carrying a torch for heating at least one of a cutting element, a tool body, and a bonding material.

Abstract: Earth-boring tools such as, for example, earth-boring rotary drill bits include erosion-resistant structures disposed proximate areas of intersection between faces of the tools and fluid nozzle recesses or fluid passageways extending through the tools to the face. In some embodiments, such an erosion-resistant structure may comprise a mass of hardfacing material. In additional embodiments, such an erosion-resistant structure comprises an erosion-resistant insert. Methods of forming such earth-boring tools include providing erosion-resistant structures proximate intersections between the faces of the tools and fluid nozzle recesses or fluid passageways extending through the tools. Methods of repairing earth-boring tools include providing an annular-shaped, erosion-resistant structure over an eroded surface of a body of a previously used earth-boring tool proximate an intersection between an outer face of the body and an inner surface of the body.

Abstract: A system and method for the welding of drill bits using an automated robot or robots.

Abstract: A system and method for the automated or “robotic” application of hardfacing to a surface of a drill bit.

Abstract: The present invention relates to a system and method for automated or “robotic” application of hardfacing to the surface of a steel-toothed cutter of a rock bit. In particular, the system incorporates a grounded adapter plate and chuck mounted to a robotic arm for grasping and manipulating a rock bit cutter beneath an electrical or photonic energy welding source, such as a plasma arc welding torch manipulated by a positioner. In this configuration, the torch is positioned substantially vertically and oscillated along a horizontal axis as the cutter is manipulated relative along a target path for the distribution of hardfacing. Moving the cutter beneath the torch allows more areas of more teeth to be overlayed, and allows superior placement for operational feedback, such as automatic positioning and parameter correction. In the preferred embodiment, sensors provide data to the control system for identification, positioning, welding program selection, and welding program correction.

Abstract: A drill bit for drilling a wellbore, the drill bit having a cutter which has tungsten carbide inserts and a spear point. The spear point has a neck that joins a smooth portion of the cutter and blades that extend from the neck and converge to an apex. The blades define valleys or spaces between them. A layer of hardfacing is applied to the entire spear point including the interim spaces and the neck.

Abstract: A shank configuration for rotary drill bits is disclosed for positioning of the shank in relation to the bit body. A tapered surface or feature of the shank may be configured and sized to matingly engage a complementarily shaped surface or feature of the drill bit body and thereby become centered or positioned in relation thereto. A deformable element may be disposed between the shank and bit body. Also, the shank may comprise a material having a carbon equivalent of less than about 0.35%. A multi-pass weld procedure may be employed to affix the shank and bit body to one another wherein welds may be formed so that one weld originates at a circumferential position that differs from the origination circumferential position of its immediately preceding weld by at least about 90°. Further, a stress state may be developed within the multi-pass weld. A method of manufacture is also disclosed.

Abstract: A shank configuration for rotary drill bits, is disclosed for positioning of the shank in relation to the bit body. A tapered surface or feature of the shank may be configured and sized to matingly engage a complementarily shaped surface or feature of the drill bit body and thereby become centered or positioned in relation thereto. A deformable element may be disposed between the shank and bit body. Also, the shank may comprise a material having a carbon equivalent of less than about 0.35%. A multi-pass weld procedure may be employed to affix the shank and bit body to one another wherein welds may be formed so that one weld originates at a circumferential position that differs from the origination circumferential position of its immediately preceding weld by at least about 90%. Further, a stress state may be developed within the multi-pass weld. A method of manufacture is also disclosed.

Abstract: A shank configuration for rotary drill bits is disclosed for positioning of the shank in relation to the bit body. A tapered surface or feature of the shank may be configured and sized to matingly engage a complementarily shaped surface or feature of the drill bit body and thereby become centered or positioned in relation thereto. A deformable element may be disposed between the shank and bit body. Also, the shank may comprise a material having a carbon equivalent of less than about 0.35%. A multi-pass weld procedure may be employed to affix the shank and bit body to one another wherein welds may be formed so that one weld originates at a circumferential position that differs from the origination circumferential position of its immediately preceding weld by at least about 90°. Further, a stress state may be developed within the multi-pass weld. A method of manufacture is also disclosed.

Abstract: An earth boring bit has a steel body having at least one leg with a depending bearing pin. A cone having cutting elements is rotatably mounted to the bearing pin. A ball plug weld is on the outer surface of the leg. A layer of hardfacing applied to part of the outer surface of the leg, the hardfacing having carbide particles in a matrix. A corrosion resistant coating containing at least 50% nickel is formed on parts of the outer surface of the leg that are free of the layer of hardfacing both above and below the ball plug weld.

Abstract: A shank configuration for rotary drill bits is disclosed for positioning of the shank in relation to the bit body. A tapered surface or feature of the shank may be configured and sized to matingly engage a complementarily shaped surface or feature of the drill bit body and thereby become centered or positioned in relation thereto. A deformable element may be disposed between the shank and bit body. Also, the shank may comprise a material having a carbon equivalent of less than about 0.35%. A multi-pass weld procedure may be employed to affix the shank and bit body to one another wherein welds may be formed so that one weld originates at a circumferential position that differs from the origination circumferential position of its immediately preceding weld by at least about 90°. Further, a stress state may be developed within the multi-pass weld. A method of manufacture is also disclosed.

Abstract: A rotary cone earth boring bit has at least one bit leg with a cone retaining ball passage that intersects an outer surface of the bit leg and is closed by a ball plug. An upwardly curved lower hardfacing bead is on the outer surface of the bit leg at least partially below the ball plug. A downwardly curved upper hardfacing bead is on the outer surface of the bit leg at least partially above the ball plug. The upper hardfacing bead has leading and trailing ends that join the lower hardfacing bead. The upper and lower hardfacing beads define a generally elliptical perimeter surround the ball plug. At least one transverse bead is above the upper hardfacing bead and leads generally upwardly and circumferentially from a leading edge of the bit leg to a trailing edge of the bit leg.

Abstract: An earth-boring bit has a bit body, at least one cantilevered bearing shaft depending inwardly and downwardly from the bit body, and a cutter mounted for rotation on the bearing shaft. The cutter includes a plurality of teeth that are covered with a hardfacing layer. At least some of the teeth have a leading side that has a streamlined contour. The streamlined contour is generally conical in some of the embodiments. In others, the streamlined contour is defined by a corner between diverging inner and outer sections of the leading side.

Abstract: An earth-boring bit has a bit body, at least one cantilevered bearing shaft depending inwardly and downwardly from the bit body, and a cutter mounted for rotation on the bearing shaft. The cutter includes a plurality of teeth that are covered with a hardfacing layer. At least some of the teeth have a leading side that has a streamlined contour. The streamlined contour is generally conical in some of the embodiments. In others, the streamlined contour is defined by a corner between diverging inner and outer sections of the leading side.

Abstract: An earth-boring bit has hardfacing that has multiple grades and an overlapped portion. One of the layers is of a different grade than the other so as to provide more wear resistance. The other provides more toughness than the wear resistant layer. The more wear resistant layer has a greater volumetric density of carbide particles. The greater density is primarily achieved by using a majority of the particles of smaller dimension than in the less wear resistant hardfacing. The overlapped portion may be on an outer or gage end of the outer row of teeth.

Abstract: An earth-boring bit has rolling cutters, each attached to a bit leg depending from a bit body. Each of the cutters has hardfaced, milled teeth. A spear point is located on one of the cutters. The spear point has a neck that protrudes toward the axis of the bit from a conical portion of the cutter. Blades are located on the spear point with spaces located between the blades. A layer of hardfacing is applied to the entire spear point area including the blades, the spaces and the neck.

Abstract: A hardfacing composition for an earth-boring bit has a quantity macrocrystalline tungsten carbide particles and a quantity of spherical cast tungsten carbide pellets. The particles and pellets are contained within a metal matrix which forms the balance of the composition.

Abstract: A hardfacing composition comprises at least 60% by weight of hard metal granules including a quantity of sintered carbide pellets and a quantity of cast carbide pellets. The cast and sintered carbides are selected from the group of carbides consisting of chromium, molybdenum, niobium, tantalum, titanium, tungsten, and vanadium carbides and alloys and mixtures thereof. The balance of the hardfacing composition is matrix metal with traces of flux or deoxidizer, and alloying elements. All percentages given are pre-application ratios.