Abstract: A replaceable cutting bit for insertion in a bit holder. The cutting bit includes a carbide ballistic compact having polycrystalline diamond layer brazed into a cavity defined in a protective ring. The cutting bit further includes a steel base having a hexagonal portion adapted for engagement with a wrench of other tool. The steel base defines a cavity into which a first hardened washer coated with abrasion resistant material is provided. The cutting bit further includes a second hardened washer coated with abrasion resistant material that is adapted to rotate relative to the first washer when the cutting bit is in operation in a bit holder.

Abstract: A cutting tool configuration includes a cutting bit insert configured in the shape of an octagonal pyramid. The cutting bit insert includes a number of portions, each of which has faces which slope at different angles with respect to the longitudinal axis of the cutting bit insert. The cutting bit insert also includes a flange which is surrounded by a ring. The ring is softer than the cutting bit insert.

Abstract: An insert cooperates with the channel in a material moving board. The insert is adapted to reach at least 3/4 of the way from the front edge to the rear edge of the board. The insert is preferably brazed to the channel and is made primarily of tungsten carbide and a cobalt binder.

Abstract: A method for removing pavement marking and a drum unit for use in practicing the method. The drum unit is mounted in a drive unit on a horizontal rotational axis. A plurality of cutting bit holders, known as blocks, are secured to the outer cylindrical surface of the drum, and there are a plurality of cutting bits that can be repeatedly installed in and removed from the holders. The blocks and cutting bits are arranged so as to produce chipping grooves in pavement sufficiently closely spaced for removing pavement markings and a thin layer of underlying pavement, while leaving an acceptably smooth surface. To produce the sufficiently closely spaced chipping grooves on pavement, the holders and cutting bits are arranged in a regular pattern with interlacing (also referred to as "lacing" or "flighting"). The holders and bits produce chipping grooves on pavement that are laterally spaced within approximately 1/2 inch of each other, and preferably closer.

Abstract: An improved cutting bit and associated holding block assembly for use on rotary wheel, chain or rotor cutters of the type having a plurality of cutting bits projecting outwards from the periphery of the wheel, chain or rotor and used to cut tree stumps or other hard or refractory materials includes individual holding blocks which each rotatably support within a bore therewithin a separate cylindrical cutting bit. The bore is canted inwards with respect to a radius of the wheel, chain or rotor, thus causing the outermost portion of a rotatable bit held in the bore to contact a surface to be worked at a negative top rake angle as the bit is rotated into contact with the work surface. The negative top rake angle advantageously provides clearance for chips severed by the bit.

Abstract: A shield for improving the wear resistance and life of holding support blocks for cylindrical carbide-tipped cutting bits used in drum pulverizer and wheel machines of the type used for pulverizing and cutting refractory materials is disclosed. The shield includes a short cylindrical metal container having a bottom annular wall supporting a coaxial central tube section. The annular space between the tube and inner surface of the cylindrical wall of the container contains and is hard brazed to solid tungsten carbide segments in the shape of sectors of a flat annular ring whose upper surface is parallel to the upper annular wall surface of the outer cylindrical wall of the container. The bore of the central tube is adapted to receive the shank of a cutting-bit, and the bottom wall of the cylindrical container of the shield is welded to the face of a cutting-bit holding block, with the bores of holding block and tube aligned, to permit insertion and removal of cutting bits into the bore of the holding block.

Abstract: A rotatable cutting bit shield and method and apparatus for attaching the shield onto cylindrical cutting bit shafts uses an annular metal ring having the shape of an inverted dish, and a centrally located hole through the ring. The diameter of the hole is initially larger than the diameter of the cutting bit shank. Compressive pressure exerted on the annular upper and lower faces of the ring by the apparatus according to the method causes the ring to deform into a flatter, more disc-shaped structure. This deformation causes the diameter of the central hole in the ring to shrink, captivating the ring axially between larger diameter annular flanges on the cutting bit shank.

Abstract: A rotatable cutting bit shield and method and apparatus for attaching the shield onto cylindrical cutting bit shafts uses an annular metal ring having the shape of an inverted dish, and a centrally located hole through the ring. The diameter of the hole is initially larger than the diameter of the cutting bit shank. Compressive pressure exerted on the annular upper and lower faces of the ring by the apparatus according to the method causes the ring to deform into a flatter, more disc-shaped structure. This deformation causes the diameter of the central hole in the ring to shrink, captivating the ring axially between larger diameter annular flanges on the cutting bit shank.