Abstract: The invention relates to a percussion device comprising two percussion pistons alternately making a percussion motion and a control valve for controlling the percussion pistons. The control valve (7) comprises a slide (8) affected by a force so that the slide is generally in a first position, but moves at the end of the percussion motion of the first percussion piston from the first position to a second position and correspondingly back to the first position at the end of the percussion motion of the second percussion piston (4).

Abstract: The present invention relates to a method of depositing a crystalline &agr;-Al2O3-layer onto a cutting tool insert by Chemical Vapor Deposition at a temperature of from about 625 to about 800° C.

Abstract: A dense cemented carbide product is described. The product is manufactured from WC with a grain size between 0.1 and 0.4 &mgr;m, fine grain size cobalt and ruthenium powders. The product is used in PCB machining operations where the addition of 10-25% Ru to the binder phase offers up to 25% wear resistant increases and up to 100% increase in chipping resistance in PCB routing compared to conventional materials (6% cobalt and 0.4 &mgr;m grain size).

Abstract: A device for towing a train of carriages of a sorting machine includes a pair of wheels driven by respective motors, which wheels engage a blade arranged below the carriages. Each towing wheel is movable toward and away from the blade relative to its respective motor, whereby the inertia of the member that has to be moved in response to a misalignment of the blade is low.

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 threading tap for cutting threads in blind holes includes an elongated body with a central axis, the body having at a rear end a connector portion, and having at a front end a threading portion. The threading portion is provided with at least one helical thread-cutting structure and interconnected flank portions defining at least one helical flute which interrupts the helical thread cutting structure. The flank portions present exposed surfaces that are steam tempered. The rest of the tap is coated by PVD.

Abstract: Feed back vibrations of a metallic tool generated during the machining of metallic workpieces are damped by detecting an oscillatory motion of the tool, identifying a frequency of the oscillatory motion and generating a mechanical camping force having the same frequency as the oscillatory motion and applied to the tool in counter-direction to a velocity of the oscillatory motion. The damping force can be of constant amplitude or gradually decreasing amplitude.

Abstract: A substrate is printed with areas of magnetizable ink. The magnetizable ink is compressed into the surface of the substrate, and overprinted to hide it. Suitable inks for the purpose are disclosed. The ink may be permanently magnetized in any of a variety of patterns.

Abstract: A sorting system includes trolleys traveling along a path between respective stations for loading and unloading items in a direction transversely of the direction of travel of the trolleys. Each station includes an inductor for generating a variable magnetic induction field which is sensed by a detecting mechanism, such as an antenna, disposed on the trolley. In response to the magnetic induction field being detected, a loading/unloading device on the trolley (e.g., an endless belt) is actuated to load or unload items.

Abstract: An impact device for a rock drill or the like, comprising means for delivering a stroke, or a stress pulse, at a tool connected to the impact device. The means for delivering a stress pulse comprise an impact element (2) supported to a frame (1a) of the impact device, and means for subjecting the impact element to stress and correspondingly for releasing the impact element (2) suddenly from stress, whereupon the stress energy is discharged in the form of a stress pulse directed at the tool (3) that is directly or indirectly connected to the impact element.

Abstract: A holder is designed to receive a cutting insert intended for parting and grooving operations. The insert is clampable in a seat formed between a blade tongue and a clamping finger which respectively extend from lower and upper front parts of the holder. A gap separates those front parts in order to enable those parts to be forced towards each other by means of a clamping mechanism mounted in the holder. The clamping mechanism comprises a drawbar, a first end portion of which is movable within a bore formed in one of the front parts, and a second end portion of which is fixed in the other front part. The first end portion of the drawbar includes a head having a frusto-conical abutment surface. A tightening screw is threadedly mounted in the same front part as the head and is arranged to contact the abutment surface to displace the drawbar in a direction forcing the clamping finger and the tongue together to clamp the cutting insert in place.

Abstract: A method and a computer program for controlling a drilling cycle in a rock drilling apparatus, and a rock drilling apparatus. In accordance with the invention, each drilling unit in the rock drilling apparatus is monitored during a drilling period, and a drilling sequence of a control unit in the rock drilling apparatus is updated at predetermined intervals during the drilling period. The total time of the drilling and the time elapsed for different operations can be registered. In addition, according to an embodiment, the drilling sequence is changed during updating, if changes occur in the drilling conditions during the drilling period.

Abstract: The present invention relates to a cutting tool with increased tool life when machining grey cast iron. The tool comprises a solid CBN-containing body containing more than 60 vol % CBN and a coating. The coating consists of at least one layer of metal nitride, carbonitride or carbide with the metal elements selected from at least one of Ti, Nb, Hf, V, Ta, Mo, Zr, Cr, W and Al, with a total thickness of 2-7 &mgr;m and 2-8 &mgr;m of &agr;- and/or &kgr;-Al2O3. The coating is a CVD coating deposited at 900° C. or higher.

Abstract: An indexable cutting plate for ball race milling cutters includes upper and lower parallel surfaces, and an edge surface interconnecting the upper and lower surfaces. Cutting edges are defined by lines of intersection between the edge surface and the upper surface. The cutting edges include a main cutting edge extending radially with reference to an axis of rotation of the cutter, auxiliary cutting edge extending mainly axially, and an angle cutting edge defining a transition between the main and auxiliary cutting edges. The auxiliary cutting edge has a radius of curvature that is larger than that of the angle cutting edge and smaller than twice the diameter of the cutting head on which the cutting plate is mounted.

Abstract: A rotary tool includes first and second tool bodies defining an axis and clamped together in the axial direction by a screw. The tool bodies include axially extending male and female parts that engage one another to transmit rotary force. Spaced radially outwardly of the male and female parts are two sets of radial guiding structures for guiding the tool bodies in the radial direction, so a radial play can exist between the male and female parts.

Abstract: A coated cutting tool is composed of one or more layers of refractory compounds of which at least one layer is single-phase &agr;-alumina with a pronounced columnar grain-structure and strong texture in the [300]-direction. The alumina layer is preferably deposited by CVD (Chemical Vapor Deposition) and the preferred microstructure and texture are achieved by adding a second metal halide, and a texture modifying agent, to the reaction gas. When coated cemented carbide cutting tools according to the invention are used in the machining of steel or cast iron, several important improvements compared to prior art have been observed, particularly in the machining of nodular cast iron.

Abstract: An arrangement for feeding soldering material into a space between a bolt and rock includes a sleeve-like nozzle which can be pushed tightly against a feed chamber on the rock bolt so that a feed hole in the feed chamber is connected to the inner space of the nozzle. The arrangement further includes a device for placing the nozzle around the feed chamber so that soldering material can be fed from the inner space of the nozzle into the drill hole.

Abstract: The invention relates to the use of PVD technique for the application of a low static friction and wear resistant coating consisting essentially of titanium nitride or a diamond-like carbon—DLC, with or without an addition of tungsten carbide, on a stainless steel, in one and the same operation as the surface hardening of the stainless steel. In this way, in one single operation, a low static friction is obtained on a very hard and wear resistant surface. Moreover, the dimensions of the work-piece are maintained unaltered, which makes the invention very useful in the production of, e.g., cam followers, cylinder tubes and piston rods for shock absorbers. The used stainless steel has the following composition (in weight %): carbon max about 0.1; nitrogen max about 0.1; copper from about 0.5 to about 4; chromium from about 10 to about 14; molybdenum from about 0.5 to about 6; nickel from about 7 to about 11; cobalt 0 to about 9; tantalum max about 0.1; niobium max about 0.1; vanadium max 0.

Abstract: The rock drilling rig comprises a first control unit (8) arranged on a carrier (1) and a second control unit (9) arranged to a rock drilling apparatus (4). The first control unit (8) and the second control unit (9) communicate with each other by means of a first data communications link (10). The rock drilling apparatus (4) has one or more sensors (11, 12, 15), the measuring results of which are processed in the second control unit (9) and only then transmitted to the first control unit (8) that controls actuators regulating the operation of the rock drilling apparatus (4). Correspondingly, the rock breaking machine, such as a breaking hammer, comprises one or more sensors (11, 12, 15) and a control unit (9).

Abstract: An end protector for a working element of a road grading machine or the like. The working element includes a body portion having a plurality of holes therein for holding picks that work a road surface. The end protector is held in place through the use of a vacant pick hole of the working element by a fastening element that extends through the hole.