Abstract: Disclosed is a wear resistant cutting insert for use in rolling cutter drill bits. The insert has a cylindrical shank that is readily fitted in an interfering manner into cylindrical sockets formed in the rolling cutter. The surface of die insert that engages the formation, however, is none-circular, and preferably, oval shaped. To prevent the insert from turning in the socket, a shallow counterbore is formed about the socket that accommodates the shape of the top, non-cylindrical portion of the insert. The depth of the recess is made slightly greater than the length of the shank of the insert so that the load applied to insert during operation is not transmitted through the shank to the bottom of the socket in the cutter.

Abstract: A rock drill head including a radially extending groove (2a) formed in a head body, a recess (5) formed inside the groove (2a); and at least two, substantially plate-shaped, hard-material inserts located in the groove (2a) and having each a radially extending, segment (4a, 4b) engaging in the recess (5).

Abstract: A drill bit for use in rotary hammer drilling machines to drill holes in rock, masonry and concrete which includes an axially extending shank having a plurality of helical discharge grooves therein and defining a convex end face. A cylindrical projection is centrally disposed on the end face of the shank and defines a pyramid-shaped cutting tip. A plurality of primary cutting members, generally rectangular in configuration, are embedded in the shank such that the cutting members are spaced from and extend radially from the cylindrical projection so as to define gaps between the cutting members and the projection. One of the cutting members is laterally adjacent an upper end portion of each of the discharge grooves.

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 rock drill has at least one hard material insert (2) with at least two cutting edges (3, 7) consisting of hard material and extending radially to the drill axis (A), whereby, in a radial range of 20% to 50% of their drilling radius, at least two cutting edges (3, 7) each have an axial recess (4), and the cutting edges (3, 7) rotating around the drill axis (A) extend with their cutting edges in their entirety without any gaps over the entire drilling radius.

Abstract: A cutting tool (200, 202) has a longitudinally extending shaft portion (208) with a chucking part (204) and a cutting head (206). A cutting edge (220) is formed on the cutting head (206). The cutting edge (220) includes at least one cutting portion. A rake surface (224) is formed adjacent to at least one of the cutting portions (220) with the rake face being at a rake angle in the range from about −10° to about 10°. A clearance face (226) is formed adjacent to the at least one cutting portion opposite the rake face (224). The clearance face (226) is at a clearance angle in the range from about 10° to about 50°. An edge radius between the rake face and the clearance face is at a radius of from about 0.0003 to about 0.0040 inch.

Abstract: A drill bit is provided for drilling holes in hard, reinforced material, including reinforced concrete. According to one aspect of the invention, wear-resistant inserts are provided in a cross-shaped pattern. The inserts ensure that the entire bottom surface of the drilled hole is engaged during each drill bit revolution. The inserts may be secured in pockets or slots. Fluid entry ports may be located between the inserts for efficient handling of drilling fluid and removal of drilled material, without impairing the structural integrity of the drill bit. According to another aspect of the invention, the drilling surface is separated into two or more stages to increase drilling efficiency, especially through composite material such as reinforced concrete.

Abstract: A masonry drill bit 1 having an active diameter of D, comprising a shaft 3 and a tip 5 for engaging a workpiece, the tip 5 including a central portion 11 extending ahead of an outer portion 13, wherein the central portion 11 has a width of at least 0.25D and is shaped to act as a chisel during percussion drilling, and wherein the outer portion 13 is shaped to cut a workpiece as the drill bit rotates. By virtue of the drill bit tip 5 configuration as described and claimed herein, a masonry drill bit 1 having improved performance is provided.

Abstract: A percussion drill bit is provided that has at least two different pluralities of inserts extending from the bit head to better match the conditions seen on the bit head during drilling. The preferred embodiment has a plurality of large inserts with a polycrystalline diamond layer located at least in the gage row and a plurality of smaller inserts located at least in the inner rows.

Abstract: A rotatable cutting bit for penetrating an earth formation wherein the rotatable cutting bit includes an elongate bit body having a forward end and a rearward end. The bit body further defines a peripheral surface. The bit body has a first cutting insert affixed thereto at the axially forward end thereof. The first cutting insert has a first leading cutting edge and a first side clearance cutting edge. The first cutting insert is attached to the bit body so that the first side clearance cutting edge radially extends past the peripheral surface of the bit body so as to engage the earth formation.

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 rock drill bit for percussive drilling, especially top hammer drilling, includes a bit head provided with front rock crushing buttons and a skirt. The bit head is provided with a number of grooves formed in the outside of the skirt and extending in the axial direction of the drill bit. Protruding lands are defined between the grooves, which likewise extend in the axial direction. Axially rearward ends of at least some of the lands are formed with retrac teeth. Each retrac tooth has a cutting edge extending along an outer circumference of the skirt.

Abstract: A solid hard metal head for a drill, including two main cutting edges (2) arranged substantially diametrially opposite each other, and two auxiliary cutting edges (3) likewise arranged substantially diametrically opposite each other, with associated main cutting edge (2) and auxiliary cutting edge (3) form an acute angle (&agr;) there between, and with the auxiliary cutting edges (3) being arranged, with respect to the rotational direction (&ohgr;) of the drill, in front of the respective, associated therewith, main cutting edge (2).

Abstract: The drill bit for drilling rock has an elongated shaft and at least one cutting plate at one end. A clearance angle &bgr; of the cutting edges, at least in segments, increases with increasing distance from the rotary axis. A wedge angle &ggr; of the cutting edges, at least in segments, decreases with increasing distance from the rotary axis.

Abstract: A rock drill which has a cutting tip of roof-shaped design at its front end is proposed. In order to achieve a reduction in the loading of the carbide cutting tip or an increased drilling capacity in particular in concrete, the flanks are subdivided into flank sections in order to achieve a slimmer embodiment of the drill head.

Abstract: A cutting bit has a bit body which has a forward end and a rearward end. The bit body contains a seat at the forward end thereof. The bit body contains a bore intersecting the seat wherein a bore wall defines the bore. A cutting insert is received by the seat wherein the cutting insert presents a side surface facing the bore. A wedge has a generally longitudinal seating surface. The wedge has a support surface opposite to the longitudinal seating surface. The wedge is received within the bore so that the longitudinal seating surface of the wedge contacts the side surface of the cutting insert and for at least a portion of the length of the wedge the entire support surface contacts the bore wall so as to frictionally retain the cutting insert in the seat.

Abstract: A cutting element, or insert, is provided for use with drills used in the drilling and boring of subterranean formations. This new insert has improved wear characteristics while maximizing the manufacturability and cost effectiveness of the insert. This invention accomplishes these objectives by employing a superabrasive diamond layer of increased depth and by making use of diamond layer surface shape that is generally convex.

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 drill for forming bores in constructional components, and including a sleeve-shaped stem (2; 12; 22; 32; 42; 52) having an axially-extending through-bore (3; 13; 23; 33; 43; 53) which opens into mouth openings (7; 10; 14; 24; 34; 44; 54) formed in opposite end sections of the stem (2; 12; 2; 32; 42; 52); a shank (5) provided at a rear end of the stem, and a drilling head (8; 15; 25; 35; 45; 55) formed of a hard material and secured in at least one slot (19; 29; 49; 59) formed in a free front end of the stem (2; 12; 22; 32; 42; 52), with a section of the drilling head (8; 15; 25; 32; 45; 55), which is embedded in the stem (2; 12; 22; 32; 42; 52), flatly engaging a material of the stem (2; 12; 22; 32; 42; 52) and being fixedly connected with the stem material.

Abstract: A rotatable cutting bit for penetrating an earth formation wherein the rotatable cutting bit includes an elongate bit body having a forward end and a rearward end. The bit body further defines a peripheral surface. The bit body has a first cutting insert affixed thereto at the axially forward end thereof. The first cutting insert has a first leading cutting edge and a first side clearance cutting edge. The first cutting insert is attached to the bit body so that the first side clearance cutting edge radially extends past the peripheral surface of the bit body so as to engage the earth formation.

Abstract: A cutting tool (200, 202) has a longitudinally extending shaft portion (208) with a chucking part (204) and a cutting head (206). A cutting edge (220) is formed on the cutting head (206). The cutting edge (220) includes at least one cutting portion. A rake surface (224) is formed adjacent to at least one of the cutting portions (220) with the rake face being at a rake angle in the range from about −10° to about 10°. A clearance face (226) is formed adjacent to the at least one cutting portion opposite the rake face (224). The clearance face (226) is at a clearance angle in the range from about 10° to about 50°. An edge radius between the rake face and the clearance face is at a radius of from about 0.0003 to about 0.0040 inch.