Abstract: A drill bit for drilling a hole in the ground, with cutting elements annularly cutting a core which, when it has reached a certain height, is continuously crushed by teeth on rolling cones. By combining these two processes, cutting and crushing, in this manner an improved drilling advancement is achieved as compared to separate use of the same processes. The cutting elements show relatively small variations as to radial positioning, which renders it possible to find a common approximately optimal rotational speed of said elements. The core is weak and may be drilled out relatively easily by the aid of crushing, as compared to drilling pure holes. This is due to the fact that the core geometry causes a more efficient growth of fractures for each tooth penetration, and that the core, due to annular cutting, is free from radial tensions from the surrounding rock formations.

Abstract: A drill bit for earth boring purposes includes a drill bit body which is rotatable about a drilling axis, a single cutting member mounted rotatably on the body and a counter-reaction member also mounted on the body. The counter-reaction member extends partially downwardly from the body and includes first and second outwardly exposed surfaces. The first surface has a greater surface area than the second surface and is at least partially formed with a circumferentially disposed curvature and a longitudinally disposed curvature with respect to the drilling axis so that it can closely conform to and contact the curvature of the bottom of the hole formed by the drill bit. The first surface of the counter-reaction member acts as a friction pad to counteract the torque effects of rotating the drill bit about the drilling axis and the cutting member engaging in the ground.

Abstract: An earth drilling bit that cuts concentric annular kerfs ahead of primary drilling means and thereby increases drilling rate. The bit includes a bit body having a lower end forming an annular cutter for cutting an outer annular kerf, an inner drill member positioned concentrically within the bit body having a lower end forming an annular cutter for cutting an inner annular kerf, a plurality of rotary drilling members attachedly arranged between the bit body and inner drill member positioned so lowermost cutting edges are above lowermost edges of the annular cutters of the bit body and inner drill member for removing material between the outer and inner annular kerfs, and plurality of drilling members attachedly arranged within the inner drill member positioned so lowermost cutting edges are above lowermost edges of the annular cutter of the inner drill member for removing material within the inner annular kerf.

Abstract: A mechanism is disclosed for rock bits whereby cutting elements, rotatably mounted to fixtures with journals, are constantly forced to rotate or precess by the interaction of the earth formation and the cutter. The cutters are fixed in skewed or offset positions on a cutting face of a rotary drill bit head. These cutting elements act as drag or shear cutters when they are operated in an earth formation.

Abstract: A shield tunneling machine comprises a tubular shield body, a partition wall provided in the shield body, a rotary shaft supported rotatably by the partition wall and extending longitudinally of the shield body, a cutter head disposed on the front end of the rotary shaft and a mechanism for rotating the cutter head through the rotary shaft. The cutter head comprises a first cutter provided with a plurality of cutter bits and a second cutter provided with a plurality of roller bits. The machine also comprises a mechanism for moving straight forward and backward one of the first and second cutters relative to the other. The machine locates the first cutter more forward than the second cutter for excavating the face of stratum having a soft layer like clay layer with the first cutter and the second cutter more forward than the first cutter for excavating the face of the stratum having a hard layer like bedrock layer with the second cutter.

Abstract: A drilling bit comprising a drill body formed from a base portion and a crown portion having a plurality of cutting elements; the base and crown portions are interengaged by a connection portion. An external opening in the crown portion communicates with a core-receiving section in the connecting portion. A core milling assembly, comprising a pair of rotatable, frustum-shaped rotary members, is supported in the connecting section. Each rotary member carries a plurality of cutting elements. During drilling, a core is received in the core-receiving section, where it is milled by the rotation of the rotary members.

Abstract: A rotatable cutter head for a pit boring machine used in reverse circulation drilling. The cutter head has cutter arrays including rotary cutters and drag cutters and disposed radially and circumferentially spaced positions on the cutter head, the drag cutters having the cutting ends lying generally in a conical plane having the axis coaxial with the axis of rotation of the cutter head. The rotary cutters each have cutting teeth around the circumference thereof and each tooth has an inclined side face lying in a further conical plane the central axis of which is coaxial with the axis of rotation of the rotary cutter, the inclined side face of each tooth facing generally along the inclination of the conical plane in which the cutting ends of the drag cutters lie, and the tip of each cutting tooth of each rotary cutter projecting beyond the plane in which the cutting ends of the drag cutters lie.

Abstract: A rotary drill bit comprising a bit body having at least one depending leg at its lower end and at least one roller cutter rotatably mounted on the leg. The roller cutter comprises a frustoconical roller cutter body and a plurality of cutting elements projecting from the cutter body to tips adapted to bear on the bottom of the well bore, with the tips defining, upon rotation of the bit, a first cutting surface of the bit extending over substantially the entire area of the bottom of the well bore. At least one drag cutter extends down from the bit body and comprises a support and a plurality of drag cutting elements on the support, each having a lower cutting edge.

Abstract: Abrasion cutting elements of a rotary drill bit are operatively connected to the bit body structure by means for yieldably supporting the abrasion cutting elements and for forcing them into a continuous drag mode of cutting contact with the earth formation. The drill bit may also employ compression or indentor cutting elements operatively attached in fixed operative positions. The yieldably supporting and force applying means may be hydraulically controlled by drilling fluid pressure and the cutting force applied on the abrasion cutting elements can be established independently of the axial cutting force transferred from the drill string and drill bit to the indentor cutting elements. Optimum performance of both the abrasion and indentor types of cutting elements is secured. The abrasion cutting elements are preferably retained for contacting and cutting the gage corner material.

Abstract: This concept discloses a new technique which uses brazing or diffusion bonding methods to attach a diamond disk to a wedge-shaped steel support platform on a hybrid type of bit. The invention is primarily concerned with the attachment of the innermost diamond cutting disk on the wedge-shaped drag bit face portion of the hybrid bit. It is particularly difficult to secure any kind of cutting structure to the innermost portion of a rock bit because of the lack of material available to secure the cutting structure to the drag bit face. Space limitations on the drag bit face prevent the use of conventional interference fit diamond insert studs for the innermost cutters.

Abstract: A hybrid rock bit is disclosed wherein a pair of opposing extended nozzle drag bit legs are positioned adjacent a pair of opposed tungsten carbide roller cones. The extended nozzle face nearest the hole bottom has a multiplicity of diamond inserts mounted therein. The diamond inserts are strategically positioned to remove the ridges between the kerf rows in the hole bottom formed by the inserts in the roller cones.

Abstract: A hybrid rock bit is disclosed which consists of a pair of cone cutters mounted to legs 120.degree. apart with an extended drag bit leg occupying the remaining 120.degree. segment. Several synthetic diamond stand-off type studs are strategically located and inserted in insert holes formed in the face of the drag bit leg. Nozzles are placed in front of the cutting face of the diamond studs to cool and clean the studs as the bit works in a borehole.

Abstract: An improved rotary drill bit comprised of two or more elongated generally cylindrical drill members the lower ends of which form a cutting face. Each of the drill members includes a plurality of vertically spaced rows of diamond-shaped openings disposed, or formed, in the sides, or wall, thereof, the openings in adjacent rows being offset from each other and overlapping at their upper and lower ends whereby as the lower ends of the drill member wear away, cutting edges are continuously formed thereon by the diamond-shaped openings.

Abstract: An improved rotary drill bit comprised of two or more elongated generally cylindrical drill members, the lower ends of which form a cutting face. A plurality of vertically spaced rows of rotatable cutting members are positioned around and between the drill members and are journaled thereto whereby as the lowermost row of the rotatable cutting members and the lower ends of the drill members wear away, the next adjacent row of cutting members is exposed.

Abstract: A method of mining utilizing a reciprocating drive, in which a tooth is driven along a relatively straight path over an ore surface in one direction of movement so as to cut a groove therein, and then a wheel is substituted in place of the tooth and is rolled within the groove in the opposite direction, the wheel having a radially wedge-shaped circumferential edge portion which applies laterally outward and downward crumbling forces to the groove walls.Both the tooth and the wheel may be incorporated into a unitary wheel assembly as a single tool, by attaching the tooth to a point on the circumference of the wheel. The tool is then locked against rotation during its powered drive stroke in one direction, when the tooth engages the groove, but during its stroke in the other direction is released to permit rotation of the wheel.The method provides for working a number of parallel grooves concurrently, with wheels being utilized only in alternate ones of the grooves.

Abstract: A rock bit for recovering core samples is described, along with variations for drilling oil wells or the like. In each of these embodiments a plurality of diamond cutters are mounted on the bit body for cutting rock by a shearing action. Each diamond cutter is in the form of a thin diamond plate bonded to a carbide slug that is inserted into the bit body. Means are also provided for limiting the depth of penetration of the diamond cutters into the rock formation being drilled preferably in the form of rolling cone cutters having a plurality of carbide insects protruding from their surfaces. The protrusion of the carbide inserts from the surface of the cutter cones is less than the length of the diamond plate. This limits the depth that the diamond can penetrate in the rock and inhibits damage. Typically the diamond cutters are mounted for cutting one portion of the hole area by shearing action and the rolling cone cutters are mounted for cutting another portion of its area by chipping-crushing action.