Abstract: The device has a drill body, of generally cylindrical shape, connected by a flexible pipe to a high-pressure water pump placed on a low-height carrying vehicle. A striking piston is mounted movably, and is resiliently returned, in the drill body, and is subjected to a pulsed high water pressure so as to be moved with a percussive movement against a bit-carrying anvil, the pipe simultaneously transmitting to the drill body an alternating rotary movement about its principal axis. A solenoid valve, interposed between the pump and the point of departure of the pipe, receives successive electrical pulses causing opening and closing, which create shock waves in the water column contained in the pipe, which transmits these shock waves to the striking piston of the drill body. Applications: underground workings, mine workings, particularly for use in low-height galleries.

Abstract: A crusher includes a replaceable first crushing member having a first crusher surface and a replaceable second crushing member having a second crusher surface. The co-operation of the crusher surfaces is defined by at least one crusher setting parameter. From measurements of a quality parameter, which relates to the nature of the crushed material, on at least two different occasions during the service life of a set of replaceable first and second crushing members and on each occasion for at least two different settings of the crusher setting parameter, a control function can be determined that describes a value, of the at least one crusher setting parameter, which on a given occasion gives a crushed material the quality parameter of which is substantially optimal.

Abstract: A stump grinding disk includes a metallic wheel defining an axis of rotation and including a pair of side surfaces and a circumferential outer edge surface. The outer edge surface includes a plurality of circumferentially spaced recesses. Each recess extends axially completely through the disk. A plurality of side cutting elements are mounted on each side surface. A plurality of outer peripheral cutters are spaced circumferentially apart around the outer edge surface. Wear strips are mounted in respective recesses. Each wear strip includes a metal matrix in which hard particles are disposed. Each wear strip defines a radially inner surface affixed to the wheel, and a radially outer surface arranged substantially flush with adjacent portions of the outer edge surface.

Abstract: A tool such as a milling or drilling tool includes a shaft having a front recess in which a cutting head is disposed. A drawbar disposed in the shaft includes a plurality of flexible tongues disposed in the recess. The tongues form a recess in which a rear knob of the cutting head is received. A retainer urges the drawbar axially rearwardly to retain the cutting head in the recess. The shaft includes axial projections at its front end which are received in respective rearwardly open recesses of the cutting head to prevent relative rotation between the shaft and the cutting head.

Abstract: A cutter insert for disc-milling cutters, in particular, for milling crankshafts. The insert has upper and lower surfaces and circumferential lateral surfaces, which connect the upper and lower surfaces to one another. The insert includes raised swellings and/or projections on the upper surface, at least in the region of two corners, which preferably extend over the entire length of one side of the cutter insert, so that, in a view perpendicularly toward a cutting face formed by at least one of the lateral surfaces, the edge which defines the transition from the upper surface to the cutting face, has a portion projecting relative to the central edge section in the region of each of the two ends of this edge.

Abstract: A holder block is mounted on a carrier and has formed therein a first hole and a water passage. A sleeve is mounted in the first hole and receives a cutter bit. The sleeve includes a shank and an enlarged flange disposed at a front end thereof. The shank is disposed in the first hole. The flange includes a rearwardly facing shoulder bearing against an outer surface of the block. A second hole extends through the shank and the flange and is adapted to receive the cutter bit. A spray nozzle is disposed in the flange and is connected to the water passage by way of an annular groove, for receiving water which it sprays forwardly against the cutter bit.

Abstract: A hollow sleeve is mounted in a hole of a holder block to receive a rotary cutter bit. The sleeve includes a front flange and a shank extending rearwardly from the front flange and defining a longitudinal axis. The shank includes an outer periphery having a radially stepped configuration, wherein an outer surface of the shank includes a plurality of axially adjacent surface sections that become successively smaller in cross-section in a direction away from the flange. Each surface section occupies one-third of the hole length. Each surface section has longitudinally spaced front and rear ends, wherein a portion of each surface section situated between its front and rear ends is spaced farther from the axis than are the front and rear ends. Each surface section has a generally longitudinally extending groove formed therein.

Abstract: A shank milling cutter includes a cutting portion which is intended to come into engagement with the workpiece, wherein the envelope surface of the cutting portion is substantially cylindrical. At least one major cutting edge is arranged at the peripheral surface of the cutting portion and at least one minor cutting edge (face cutting edge) is arranged at the end face of the cutting portion and with an end diameter D. The minor cutting edge, in projection onto a plane containing the milling cutter axis, has a convexly curved portion with a radius of curvature R>D/2 and a center of curvature M located such that a distance from the center of curvature M to the axis is in a range from zero to a value smaller than D/2.

Abstract: A super-austenitic stainless steel alloy with a composition, balanced in such a way that products made from the alloy fulfill high requirements on a combination of high corrosion resistance, especially in inorganic and organic acids and mixtures thereof, good general corrosion resistance, good structure stability as well as improved mechanical properties in combination with good workability, in particular in tubes, especially seamless tubes and seam welded tubes for application in these environments and with following composition, in weight-percent: Cr 23.0–30.0 Ni 25.0–35.0 Mo ?2.0–6.0 Mn ?1.0–6.0 N ??0–0.4 C up to 0.05 Si up to 1.0 S up to 0.02 Cu up to 3.0 W ??0–6.0 up to 2.0 of one or more element of the group Mg, Ce, Ca, B, La, Pr, Zr, Ti, Nd, and the balance being Fe and normally occurring impurities and steel making additions.

Abstract: A threading tool for generating a thread in a workpiece, includes a threading part which defines a longitudinal axis. A cooling channel extends inside of the threading part along the axis to a front end surface thereof for supplying a coolant. Longitudinally extending passages are disposed in an outer periphery of the threading part for the return of coolant exiting the coolant channel. A diversion element is positioned at the front end surface for diverting the exiting coolant in a laterally outward direction along the front end surface toward the passages.

Abstract: A cutting insert includes a body comprising a superhard material or a superhard material and a cemented carbide, a hole through said body, and a preformed hole inlay in said hole to allow securing of the insert to a holder. The method of making same is also disclosed.

Abstract: In an insert holder for indexable cutting inserts, a clamping device is located which includes an L-shaped member having first and second arms. The first arm is received in a blind hole in the cutting insert and the second arm is actuated by a pressure screw. A free end portion of the second arm has a yoke received in a recessed annular waist portion of the screw so that movement of the screw causes the L-shaped member to rotate and push the insert downwardly against a base surface and laterally against an upright support surface. The insert has a central elevated plateau on its top side to enable a depth of the blind hole to be maximized.

Abstract: A tool for the fine-turning of grooves in workpieces including a basic body having a rearwardly extending mounting part, and a forwardly projecting bracket. The bracket includes a narrow neck part and an enlarged support part disposed at an end of the neck part. The support part, which forms an insert seat, extends laterally from the neck part wherein the seat is arranged asymmetrically with respect to an imaginary center line of the basic body. A cutting insert includes a bottom side supported on the insert seat. The insert includes two spaced apart convexly arched side cutting edges arranged so that the imaginary center line passes therebetween. A hole is provided through the insert for receiving a fastening screw. The bottom side and the insert seat include mutually engaging stabilizing structures preventing angular displacement of the insert about an axis of the hole.

Abstract: In a hydraulic system for mining equipment and a method of adjusting the power of a rock drill machine, at least one mining actuator used for detaching rock is connected to a dedicated separate hydraulic circuit having a special hydraulic pump. The power of the mining actuator is adjusted by changing the hydraulic power generated by the separate hydraulic circuit of the hydraulic pump.

Abstract: A drill bit assembly includes a drill bit having a leading end to which a drill tip is bonded. The drill tip has a front cutting edge, a pair of side cutting edges, a rear end and a pair of parallel side walls extending between the respective edges. The leading end is arranged to support the drill tip along the rear end and against the parallel side walls. The drill bit includes a bore extending axially therethrough and opening into the leading end. The drill tip extends across the bore but permits egress of flushing liquid from the bore. The drill tip includes projections arranged to cooperate with an engagement face formed at the leading end to locate the drill tip in a bonding position relative to the leading end prior to bonding of the drill tip to the leading end. The cooperation is such as to resist shifting movement of the drill tip in a direction of elongation of the tip and out of the bonding position.

Abstract: A method and an apparatus for monitoring the operation of a percussion device, which percussion device comprises a percussion piston and a pressure channel for supplying pressure medium to the percussion device for moving the percussion piston. The method and the apparatus measure pressure pulsation of the pressure medium acting in the pressure channel, which pressure pulsation is depicted as a pressure curve. From pressure pulsation are determined parameters depicting the operating state of the percussion device and the operating state of the percussion device is determined on the basis of the parameters. In addition, an arrangement for controlling the operation of the percussion device on the basis of the operating state of the percussion device.

Abstract: A method of loading cutting tool inserts in a PVD (Physical Vapor Deposition) coating equipment consists in using a tube manufactured of a non-magnetic metallic material surrounding a stack of alternating discs of a magnetic material and iron. The north poles of the magnets are directed towards each other and the cutting inserts are positioned on the outer wall of the solid tube and kept in place by the magnetic forces.

Abstract: A stainless steel, which after nitriding exhibits a hardened surface layer with a hardness of at least 1200 Hv is disclosed. The stainless steel can be in the form of wire, plate, strip, tube and pipe and other geometries, especially complex geometries, particularly useful in applications with high demands on a combination of high strength and/or toughness and wear resistance and as a substrate for coating.