Abstract: A cutting assembly includes a holder and a cutting tool body mounted in a bore of the holder, and a retainer sleeve for retaining the tool body axially within the bore while permitting the tool body to rotate freely about a longitudinal axis thereof. The retainer sleeve includes inwardly bent tongues which engage a groove formed in a shank of the tool body. The retainer sleeve is configured to facilitate the escape of fines from the groove during a cutting operation.

Abstract: A drill bit for trenchless drilling includes a bit body defining a longitudinal axis about which the drill bit is rotated during a trenchless drilling operation. Two sets of cutting teeth are mounted at a front end of the bit body, the sets disposed on opposite sides of the axis. The first and second sets are brazed into respective slots formed in the first and second side surfaces of the bit body. The slots on each side surface communicate with a common groove, wherein the groove forms a shoulder against which rear ends of the cutting teeth abut.

Abstract: A stump cutter includes a rotary drum, holders mounted on the drum, and cutting bits mounted in respective bores of each holder for rotation relative thereto. Each cutting bit includes a shank having a pocket formed in a front end thereof in which the cutting tip is brazed, wherein an outer lip of the shank tightly grips an outer side surface of the cutting tip with a thermal shrink fit. The cutting tip includes a circular cutting edge formed by the intersection between portions of the front surface and side surface of the cutting tip, which surface portions intersect at a ninety degree angle. The front surface of the cutting tip includes raised radial ribs spaced circumferentially therearound for inducing rotation of the cutting bit during a cutting operation.

Abstract: A stump grinding device includes a wheel having an outer peripheral edge in which a plurality of recesses are formed. Disposed in each recess is a plurality of cutting units each including a block affixed to a floor of the recess, and a bit mounted in the block. Each bit includes a hard tip disposed at a front end thereof. The bits of some of the peripheral cutting units are rotatable relative to their respective blocks, with the hard tips thereof being generally pointed. The bits of others of the peripheral cutting units are non-rotatable to their respective blocks, with the hard tips thereof forming elongated cutting edges. The peripheral cutting units are spaced from leading and trailing ends of the respective recesses to provide spaces for the passage of cuttings.

Abstract: A power rake attachment includes a rotary drum and a plurality of bit assemblies mounted on an outer surface of the drum. Each bit assembly includes a hollow holder affixed to the outer surface, and a cutter bit disposed in the holder. The cutter bit includes a front cutting head and a rear shank. The shank extends into the holder, and the cutting head projects longitudinally past a front end of the holder. A retainer retains the shank within the holder, and wear sleeve is disposed around an outer surface of the holder. The cutter bit includes a laterally outwardly projecting sleeve-retaining portion which extends laterally past the outer surface of the holder and into overlying relationship to a front end of the holder to retain the wear sleeve longitudinally on the holder.

Abstract: A mechanism for disintegrating breakable materials, such as wood, pipes, bricks, etc. includes a rotary drum having striker bars mounted thereon which disintegrate the breakable materials. Each striker bar has a notched cutting edge formed by a row of carbide tips sintered to an edge of a steel body. The cutting edge can be of serrated shape and/or scallop-shape.

Abstract: A stump grinding tool includes a rotary cutting wheel having a pair of side surfaces and an outer peripheral surface. Cutting assemblies are mounted on the cutting wheel, each cutting assembly including first and second pockets disposed on respective side surfaces of the wheel. Each pocket includes a leading through-hole and a trailing through-hole aligned with respective leading end trailing through-holes of the other pocket for receiving a pair of cutting teeth. Each tooth extends through aligned through-holes of the pocket and cutting wheel in mutually opposite directions, wherein cutting elements of the teeth are disposed adjacent respective ones of the side surfaces. Each tooth is fixed by a nut threaded thereon such that each tooth and associated nut functions to clamp both of the first and second pockets against the respective side-surfaces of the cutting wheel.

Abstract: A rotatable tool for breaking hard material includes an elongated tool body and a cutting cap mounted on the tool body. The cutting cap includes a generally conical front tip having a maximum first diameter (d), and a rear base portion having an outer peripheral surface defining a maximum second diameter (D). An intermediate portion extends from the tip to the base, and at least a part of the intermediate portion has a concave outer peripheral surface. A longitudinal extent (H) of the cap extends from a front end of the tip to a rear end of the outer peripheral surface of the base. A ratio of d to D is equal to or greater than 0.7. A ratio of H to D is equal to or greater than 1.0.

Abstract: A rotary roof mine bit for drilling holes in the roof of a mine, comprises a bit body and an insert mounted in the bit body. The insert is formed of a hard material such as carbide or diamond. A top surface of the insert comprises two top sections which intersect a respective main surface of the insert to define first and second non-linear cutting edge. In one embodiment each cutting edge comprises a plurality of mutually angled segments. In another embodiment each cutting edge is continuously curved. Preferably an axial notch is disposed at a center of the top surface.

Abstract: Provided is a novel rock bolt anchoring system and a method of use thereof. The reactive grouting system, comprises: (a) a resin component containing an unsaturated polyester resin; and (b) a catalyst component separated from the polyester resin. The catalyst component comprises a catalyst effective to cross-link the polyester resin and a filler having a proportion of particles having a size of from 0.01 to 100 (preferably from 0.5 to 50 .mu.m) and a mean particle size of 1 to 5 .mu.m (preferably 3 to 5 .mu.m). The system has particular applicability in the anchoring of mine bolts, facilitates installation of a reinforcing member, and is exceptionally fast in and strong upon curing.

Abstract: A mine tunnel ventilation control device and method for constructing same quickly with an easily transportable matrix material to provide a rigid flame retardant barrier wall. The air flow stopping includes a peripheral frame extending about and across a tunnel opening to which is secured a matrix material, preferably in the form of a composite including a sheet of very strong grid material, such as a biaxially oriented integral geogrid or the like, bonded to a sheet of a textile material, such as a non-woven, needle punched, geofabric or the like which spans the apertures of the geogrid. At least one side of the matrix material, and preferably both sides, are covered with a sealant composition to prevent passage of air through the mine stopping and to develop structural rigidity.

Abstract: A rotary roof mine bit for drilling holes in the roof of a mine, comprises a bit body and an insert mounted in the bit body. The insert is formed of a hard material such as carbide or diamond. A top surface of the insert comprises two top sections which intersect a respective main surface of the insert to define first and second non-linear cutting edge. In one embodiment each cutting edge comprises a plurality of mutually angled segments. In another embodiment each cutting edge is continuously curved. Preferably an axial notch is disposed at a center of the top surface.

Abstract: A method for stabilizing a subterranean formation which includes introducing a stabilizing composition into a subterranean formation, for example, by pumping into and through cracks and crevices in the formation and allowing the stabilizing compositions to cure thereby stabilizing the formation. The stabilizing composition includes a non-shrink synthetic resin, a catalyst and various additives and fillers.

Abstract: A down-the-hole hammer drill having a reverse circulation system which conducts pressurized air downwardly to a lower cutting face of a drill bit. The air travels across the cutting face and upwardly through a central exhaust passage. The air is conducted to the cutting face through longitudinal and lateral passages in the bit which are kept isolated from the environment surrounding the bit so that no appreciable amount of pressurized air can escape, and so that the passages do not become clogged with dirt. The drill bit comprises upper and lower pieces. Upper sections of the longitudinal passages are formed in the upper piece, and lower sections of the longitudinal passages are formed in the lower piece.

Abstract: An insert for use in a roof bit for drilling bolt holes in a mine roof includes a pair of cutting edges interconnected by a chisel edge. Each cutting edge is formed by an intersection of front and side faces of the insert. Each side face further includes at least one chamfer intersecting the respective cutting edge and the chisel edge to divide that cutting edge into inner and outer sections, each of which being sharper than the chisel edge.

Abstract: A roof drill bit for drilling a bolt hole in a mine roof comprises a body defining a longitudinal axis of rotation and having an external periphery and a front face. A longitudinal fluid channel is formed in the external periphery for conducting a flow of flushing fluid to the front face. An imaginary longitudinal plane which contains the axis of rotation serves to bisect the front face into first and second sides. A cutting edge arrangement is defined by at least one cutting insert mounted on the body. The insert is positioned to be acted upon by the flow of flushing fluid. At least one support pad is mounted on the external periphery for balancing cutting forces acting on the drill bit. The cutting arrangement is asymmetrical with respect to the axis of rotation such that the cutting edge arrangement is disposed on one of the sides, and the other side is substantially free of the cutting edge arrangement.

Abstract: A sprayable composition for use as a sealant or coating for various surfaces, especially concrete block walls, is disclosed which includes water soluble silicate, water, cellulose fibers, clay and limestone. The cellulose fibers enable the sealant to have a sprayable consistency and good thixotropy when the sealant composition is sprayed on a vertical surface or a ceiling. A method of using the sealant composition also is disclosed.

Abstract: A drill for cutting holes in mine roofs comprises a shank and a wedge shaped carbide cutting insert frictionally clamped within a wedge-shaped slot formed in the front end of the shank. The insert and slot include a tongue-and-recess connection which radially centers the insert within the slot.

Abstract: A driver sub and a case for enclosing a piston chamber of a percussion drill are threadedly connected by respective identical male and female screw threads. Each of the identical male and female screw threads includes a root portion, the shape of which is defined by portions of two axially overlapping ellipses interconnected by a flat.

Abstract: A percussion drill includes a reciprocating piston surrounded by a cylindrical casing. Disposed at opposite ends of the cylindrical casing are replaceable hollow cylindrical wear sleeves. The wear sleeves are mounted within recesses formed in the outer surface of the casing. Each wear sleeve has a thickness equal to the depth of its respective recess. A longitudinal inner end of each wear sleeve is spaced longitudinally from an end surface of the recess, and a flexible seal is situated between those opposing ends. The wear sleeves can be replaced after being worn by the abrasive environment encountered in the hole being drilled. The wear sleeves may be formed of a more wear resistant material than the casing.