Abstract: The present invention is directed to a twist drill which is coated with a layer of CVD diamond and which has slots in its head which are filled with CVD diamond. The invention twist drill is made by forming slots in the head of the twist drill and then subjecting the slotted twist drill to a CVD diamond deposition process for coating said twist drill with a layer of CVD diamond and for filling said slots with CVD diamond. The performance of CVD diamond-coated twist drills does not depend on retaining the diamond film over most of the areas of the drill; but, rather, drill performance is dependent upon retaining a layer of diamond on the cutting edge of the drill. The diamond-filled slots in the head of the twist drill function as wear stops and additional cutting edges as the surrounding drill material is worn away during use.

Abstract: A rotatable cutter bit for drilling a hole in the hardplate of burglar-resistant safes includes an elongate hollow barrel having diamond grit bonded in a matrix to the periphery of the work-drilling end and a beeswax core in the hollow working end. A method for drilling hardplate includes the step of rotating a diamond-tipped drill bit in the hardplate in the presence of beeswax in the drilling interface.

Abstract: A cutting tool (22) having elongate cutter arms (36) mounted about a pivot pin (40) for outward swinging movement. Cutting blades (58, 60) are mounted on the lower ends of the cutter arms (36) and have a plurality of closely fitting hard carbide cutting elements (90) secured thereto and forming an inclined leading planar cutting surface (82) inclined from the upper end of the associated blade (58, 60) at an angle A between one (1) degree and twenty (20) degrees relative to the direction of rotation. The cutting elements (90) have parallel rear and front faces (90A, 90B) connected by a peripheral side surface (90C) extending perpendicularly to the parallel faces (90A, 90B).

Abstract: This invention relates to a cutting tool material with improved toughness behavior. The improved toughness behavior is obtained by using carefully selected reinforcing materials. The objectives of this invention are realized by simultaneously utilizing additives resulting in different toughenings mechanisms. By the simultaneous utilization of different toughening additives, synergistic effects occur giving the tool excellent material properties. The tool material of the present invention comprises reinforcing whisker additives of one dimensional single crystals with preferably different diameter and aspect ratios, two dimensional single crystals with different thickness and aspect ratios, and, in combination therewith, phase transformation additives such as ZrO.sub.2.

Abstract: A polycrystalline diamond cutting element is shown which includes a mounting body having a leading face and a trailing face and a thin layer of super hard material carried on the leading face of the mounting body which defines a cutting face. The cutting face has a circular outer periphery which is interrupted to form a recess in the cutting face which continues through the mounting body. The recess mates in complementary fashion with the outer periphery of a second cutting element when the cutting elements are arranged side-by-side with the cutting faces thereof in a common plane.

Abstract: A drilling tool is made up of a holder and a drilling member detachably connected together. One of the holder and the drilling member telescopes into the other. Resilient tab-like parts on one of the holder and the drill member engages within recesses in the other for effecting a rotatably locked connection between them. Accordingly, torque can be transmitted through the drilling tool by the tab-like parts and the recesses for effecting a drilling operation. The holder and drilling member can be disconnected without the use of any auxiliary tools.

Abstract: A drag type drill bit (10) having a plurality of solid block-like holders (30, 32, 34) secured to and projecting from the bit body (12), each holder (30) having a plurality of cutting elements (36) thereon defining spaced cutting edges 54. Each cutting element (36) has a planar cutting face (46) and a cutting edge (54) extending along the cutting face (46) with the cutting face (46) extending in a generally radial direction with respect to the axis of rotation of the bit (10). The holders (30, 32, 34) are arranged in a plurality of rows extending outwardly from adjacent the axis of rotation of the drill bit (10) and the holders (30, 32, 34) in each row are staggered rearwardly with respect to the direction of rotation.

Abstract: A cutting tool (22) having elongate cutter arms (36) mounted about a pivot pin (40) for outward swinging movement. Cutting blades (58, 60) are mounted on the lower ends of the cutter arms (36) and have a plurality of closely fitting hard carbide cutting elements (90) secured thereto and forming an inclined leading planar cutting surface (82) inclined from the upper end of the associated blade (58, 60) at an angle A between one (1) degree and twenty (20) degrees relative to the direction of rotation. The cutting elements (90) have parallel rear and front faces (90A, 90B) connected by a peripheral side surface (90C) extending perpendicularly to the parallel faces (90A, 90B).

Abstract: A rotary drill bit is provided which uses a plurality of hemispherically shaped diamond cutting elements, each having a cleaved, planar face. The diamonds are disposed in the bit such that the planar faces provide a plurality of knife-like cutting surfaces which fracture the formation being drilled and groove the fractured material.

Abstract: A drill comprising a drill shank having a taper portion adjacent to a threaded portion provided on the rear or basal portion of the shank. When the drill is screwed into an axial hole in a drill holder of a drilling machine, the opening edge or inner tapered wall of the axial hole of the drill holder bites into the taper portion of the drill shank, consequently to bring the drill into firm connection with the drill holder of the drilling machine.

Abstract: A drag type rotary drill bit (10) having mounted on its lower face (22) a rigid integral holder (30) for a plurality of polycrystalline diamond compact (PDC) cutting elements (42) secured to a planar face (60) of the holder (30). An upper projecting tapered end portion (71) of the holder (30) defines tapered surfaces (72, 73) with the lower tapered surface (72) extending at a relatively large clearance angle (B) to provide a relatively small wear flat surface on the holder (30).

Abstract: A cutting element comprises a stud and a composite bonded thereto. The composite comprises a substrate formed of cemented carbide, and a diamond layer bonded to the substrate. The interface between the diamond layer and substrate is defined by alternating ridges of diamond and cemented carbide which are mutually interlocked.

Abstract: A helically fluted twist drill apparatus in which offset, opposed veins of sintered abrasive particulate, such as diamond, are embedded within a drill blank made of a less abrasive material such as carbide. The non-aligned veins of abrasive material, in one embodiment, themselves intersect through juxtapositioning adjacent the point and web of the drill, and in another embodiment, rely upon the interpositioning of a third intermediate vein which, in turn, intersects at least part of both the first and second nonintersecting veins, to describe a more economical and effective highly abrasive material region at the drill point and web locations.

Abstract: A twist drill bit includes a cylindrical body having a pair of spiral grooves formed in an outer peripheral surface of the body and extending spirally along a length thereof to a forward end of the body. Each of the grooves has a forward portion defined by a first surface which is concavely arcuate when viewed from the forward end and extends from the outer periphery of the body generally radially inwardly thereof and a second surface which is convexly arcuate when viewed from the forward end and extends from an inner end of the first surface to the outer periphery of the body. Each of the first surfaces serves as a rake surface which terminates at the forward end in a cutting edge which is concavely curved when viewed from the forward end. Each of the cutting edges is coated with a hard coating which is harder than the body. The body has a web thickness of 0.25 D to 0.5 D wherein D is a diameter of said body, and the first surface has a radius of curvature of 0.20 D to 0.

Abstract: A diamond cutter for use in a drill bit having a geometric size and shape normally characterized by unleached diamond product, such as STRATAPAX diamond cutters, can be fabricated by assembling a plurality of prefabricated leached polycrystalline diamond (PCD) elements in an array in a cutting slug. A cutting slug is formed of matrix material which in one embodiment is impregnated with diamond grit. The cutting face of the cutting slug is characterized by exposing at least one surface of each of the PCD elements disposed therein. The diamonds may be set within the cutting slug either in a compact touching array or in a spaced-apart relationship. More than one type of array may also be employed within a single cutting slug. The PCD elements can assume a variety of polyhedral shapes such as triangular prismatic elements, rectangular elements, hexagonal elements and the like. The plurality of diamond elements and the cutting slug are fabricated using hot pressing or infiltration techniques.

Abstract: The bit (1, 101, 201) includes a pointed tapered drill portion (10, 110, 210) with cutting edges (14, 114, 214), an abrasive frustoconical grinder portion (20, 120, 220), and an abrasive cylindrical reamer portion (30, 130, 230). The drill portion (10, 110, 210) produces a hole. The grinder portion (20, 120, 220) grinds and enlarges the hole. The reamer portion (30, 130, 230) finishes the hole. The drill portion (10, 110, 210) is carried by a shaft (12, 112, 212) that is received into an axial opening (40, 140, 240) through the grinder and reamer portions (20, 30, 120, 130, 220, 230). The drill portion (10) and grinder portion (20) may form a substantially continuous taper. In another embodiment, the drill portion (110) has an arrowhead configuration. In another embodiment, a radial slot (224) extends through the grinder portion (220), and the drill portion (210) extends axially and radially from the slot (224).

Abstract: A cutting tool comprised of an annular polycrystalline layer of diamond or cubic boron nitride integrally adhered to an annular recess in an upper peripheral portion of an integral cemented carbide substrate structure, said layer having a round cutting edge, one face of the layer being adhered to the bottom surface of the recess and an innular annular side of the layer being adhered to the inner wall of the recess, the thickness of the polycrystalline layer and the height of the wall being substantially equivalent.

Abstract: A drag type rotary drill bit (10) having mounted on its lower face (22) a rigid integral holder (30) for a plurality of polycrystalline diamond compact (PDC) cutting elements (42) secured to a planar face (60) of the holder (30). An upper projecting tapered end portion (71) of the holder (30) defines tapered surfaces (72, 73) with the lower tapered surface (72) extending at a relatively large clearance angle (B) to provide a relatively small wear flat surface on the holder (30).

Abstract: A rotary cutting tool, e.g. a drill bit, has a generally cylindrical working head consisting of ultrahard incisive material such as cubic polycrystalline diamond or boron nitride. The working head has at least peripheral cutting edges which may extend onto an adjoining carrier of hard metal secured thereto along a transverse interface; the carrier may be bonded at another junction to a tool body or may itself constitute such a body. Also disclosed is a method of making such a tool, particularly a drill with a working head of 5 mm or less, according to which a prefabricated block, consisting of interconnected ultrahard and metallic blanks for the head and its carrier, is soldered inside an aligning sleeve onto a cylindrical extension of the tool body whereupon the extension and the block are jointly machined to form the tool.

Abstract: A drill bit the point of which has two or more outer cutting edges and is formed with a V-shaped notch. The V-shaped notch has its center lying on the axis of rotation of the drill bit and opens in the direction of feed of the tool. The V-shaped notch defines inner cutting edges terminating in respective outer cutting edges.

Abstract: This invention relates to a tool with at least one wear-resistant hard metal part which serves to process production pieces, stones, or the like, wherein the hard metal part is firmly connected with a metallic carrier by solder located in at least one solder aperture. In order to reduce the danger of formation of tension cracks in the hard metal part, the invention provides that at least one predetermined weak point is created in the solder aperture.

Abstract: This invention relates to a tool for use in carrying out a cutting process, and more particularly to a cutting tool formed so that it can be sued to cut an iron material of a high hardness and thereby obtain a mirror-polished surface thereon, the cutting tool being characterized in that it is formed by attaching a monocrystal of boron nitride to the tip thereof so that predetermined surface and orientation of the crystal are set suitably. To be concrete, the present invention is directed to a cutting tool in which monocrystalline boron nitride is used for a tip which forms a blade of the cutting tool, (111) surface of this boron nitride being used as a relief surface of the blade, <211> direction being used as a cutting direction; or a cutting tool of the same material, in which (100) surface of the boron nitride is used as a relief surface of the blade, <110> direction being used as a cutting direction.

Abstract: At the top surface of a drill head, one or two tips are fixed radially with a little clearance from the axis of rotation, and thereby a nonmachining zone is formed around the axis of rotation. Each tip has its cutting edge formed projectingly from the radial line to a tangential direction and the distance from the axis of rotation to the cutting edge is made greater than the distance from the axis of rotation to an end face of the tip. The core which is generated and grows in the nonmachining zone in the course of machining is pressed by the end face of the tip and broken off, or is clamped between the end faces of the tips and wrenched off due to friction torque.

Abstract: A bit for a core drill of the type for drilling a chamfered hole in an article has a dynamic cooling fluid flow directing element for cooling the bit and article surfaces during drilling and chamfering of the article.

Abstract: The present invention includes an insert securably mountable within the chamber of a core drill, such as a chamfering diamond core drill used for drilling and chamfering glass articles. The insert preferably includes a first diverting facility for diverting a first portion of a lubricating/cooling fluid from within the core drill to the inner drilling surfaces of the core drill, and a second diverting facility for diverting a second portion of the lubricating/cooling fluid to the outer drilling surface and chamfering surface of the core drill, to prevent thermal damage to the article being drilled and chamfered, during both the drilling and chamfering steps. The present invention further includes a method of lubricating/cooling an article during drilling and chamfering operations with lubricating/cooling fluid from within the core drill, to prevent thermal damage to the article being drilled.

Abstract: A drill bit suitable for making holes in glass and ceramic structures has an elongated member with a cutting end and a retaining end with an axis passing through its ends. The portion of the member near the retaining end is formed as a shank which is capable of being suitably held and rotated by a chuck or the like. The shank distal to the retaining end terminates in a shoulder which tapers inwardly toward a pilot element which extends axially from the center of the shoulder coaxial with the shank. The pilot element terminates in a cutting surface with the cutting surface forming the forwardmost portion of the cutting end of the member. A cutting grit is permanently affixed at least to the cutting surface on the pilot element, the shoulder and the portion of the shank immediately adjacent to the shoulder.

Abstract: The invention provides an abrasive body suitable for mounting in a tool for abrading operations, the body including an abrasive compact comprising a mass of abrasive particles, present in an amount of at least 70 percent by volume of the compact, bonded into a hard conglomerate and support means covering a part of the surface of the compact and bonded to the compact, characterized in that the support means covers more than 50 percent of the surface of the compact and the compact presents an arcuate formation, salient in relation to the support means, capable of abrading a workpiece.

Abstract: In a device for drilling rock, concrete, reinforced concrete and similar materials, a spindle is rotatably mounted in a housing and a drilling tool is replaceably mounted on the spindle so that the spindle and drilling tool rotate together. A gear wheel is fitted on the drilling tool. A motor is located on the housing laterally spaced from the axis of rotation of the spindle. The motor includes a drive pinion which drives an intermediate gear. The intermediate gear meshes with the gear wheel and drives the drilling tool and spindle. The spacing between the axis of the intermediate gear and the spindle is adjustable.

Abstract: A portable lightweight drill assembly is mounted against one side of a sheet of flat glass having a hole or crack to be repaired; the drill shaft extends through the hole or crack to mount cutters on both sides; the cutters are spring biased against the glass to exert equal cutting force and simultaneously rotatable with the drill shaft to cut the hole from both sides to a diameter larger than the hole to be repaired, for insertion of a glass repair plug.

Abstract: A drill assembly comprising a tool bit of the type including a slot at one end for receiving a cutting element. A positioning clip removably disposed in the slot and having a cutting element engagement structure for maintaining the position of the cutting element within the retainer clip, and drill body engagement structure for locating and maintaining the position of the clip within the slot of the tool bit.

Abstract: A novel shock mounting is disclosed for ultra-hard crystalline materials. When used as a drill bit, the crystalline materials last much longer as cutting elements when mounted according to the present invention.

Abstract: There is disclosed an ablatible drill comprising a soft or frangible matrix having embedded therein a multiplicity of hard inclusions which act as cutting teeth. During drilling, the matrix gradually wears away so that worn inclusions are circulated out of the hole and fresh inclusions are exposed as new cutting teeth. A plurality of joints of the ablatible drill are interconnected on the bottom of a drill string. The comminuted material of each joint of the ablatible drill provides a characteristic distinguishable from the comminuted material of adjacent joints so that in examination of the circulated returns provides an indication of which joint is then being drilled.

Abstract: An impregnated diamond drill bit having a generally cylindrical, hollow crown structure with a lower portion containing diamond particles and a steel shank attached to the crown structure at its upper end. The diamond particles are dispersed within a metal matrix in the lower portion of the crown. Around both the outside circumferential wall and the inside circumferential wall of portions of the crown structure, there are layers of a highly wear resistant material. These layers are formed of a material that is more wear resistant than the material used for the metal matrix in which the diamond particles are dispersed.

Abstract: Improved core drills and core drill elements. The core drill is of the type having a carrying drill tube and at least one cutting element attached to one end of drill tube. In the present invention, structural means are provided on one end surface of the cutting element extending over the entire length of the end surface to receive all or a portion of the one end of the drill tube to strengthen the core drill. The invention is also directed toward a method for making the improved core drill and a method for reconstructing it. The cutting elements can be curved or straight.

Abstract: A method for repairing panes of glass is provided which enables fractured panes to be strengthened and holes refilled while the pane remains installed in its support structure. The method comprises steps for relieving stress points in a fractured pane, and for applying substantially transparent materials for filling portions of the pane where glass has been removed or separated. The method enables repair of laminated glass panes as well as solid glass panes.

Abstract: A drilling machine comprising an article holding device and two drilling devices, being characterized that each drilling device has one drill turning in the same direction at a synchronized speed, each drill approaching to or separating from each other symmetrically to make a hole from both sides of a rigid and fragile article made of glass or ceramic e.g. lenses of spectacles at the same time, and that the hole is chamfered and further a groove for fixing the article to the frame is made on the article, as required.

Abstract: An abrasive drill of small diameter is provided with a cored portion that is eccentric, i.e., lacking a substantial concentric portion, relative to the longitudinal axis of the drill. The core, regardless of shape, is located so that during drill rotation all of the surface of a workpiece within the outline of the end of the drill is abraded by some part of the rotating end of the drill. The drill composition comprises abrasive particles in a less abrasive matrix, and the core is not hollow but comprises relatively non-abrasive material. The drill is formed by deposition of matrix material entraining abrasive particles onto a taut filamentary mandrel. The mandrel preferably comprises one or more round filaments, either straight or twisted together, alongside the longitudinal axis of the drill, and may be metallic, such as copper wire or may be non-metallic, such as nylon or other synthetic polymeric textile fiber composition. The drill diameter may be on the order of a millimeter or so or smaller.

Abstract: A drill for use in drilling precious and semi-precious stones consisting of a body adapted to be rotated on its axis, said body having longitudinal cutter elements separated by longitudinal flutes, the surfaces of the body of said drill being covered by an abrasive layer consisting of a ductile metal, such as nickel, containing a multiplicity of abrasive particles.

Abstract: Disclosed is a core drill for cutting cylindrical sections from stone, glass, shell and other hard materials, while simultaneously drilling a centered hole in each cylindrical section. The drill comprises an abrasive tipped hollow cylindrical core drill and a drill bit positioned centrally within the core barrel.