Abstract: The present invention relates to a rock drill bit for percussive drilling. The drill bit comprises a bit body, a head portion defining a longitudinal center axis. The head portion includes an axially forward rock-crushing surface and a skirt that extends axially rearwardly from the rock-crushing surface. The rock-crushing surface comprises several rock-crushing means. A circumferential outer surface of the skirt is provided with circumferentially spaced apart grooves forming lands therebetween. The grooves and the lands extend generally in an axial direction. An axially rearward portion of a land is provided with a guiding surface. The guiding surface faces radially outwardly. The guiding surface comprises at least one step or a sloping surface such to reduce the diametrical dimension stepwise or continuously, respectively. The guiding surface comprises a first guiding portion and a second guiding portion both situated radially outside of an imaginary extension line of the waist.

Abstract: A roller cutter includes a hub having crushing members mounted on an outer periphery thereof, and a shaft on which the hub is mounted for rotation. Opposite ends of the shaft include respective spigots. Seals are disposed adjacent respective ends of the shaft and are arranged radially between the shaft and the hub for preventing leakage of lubricant. Covers are disposed axially outwardly of respective seals for covering the respective seals. Each cover includes a generally radially inwardly directed projection received in an indentation formed in an outer surface of the shaft to lock the cover axially and rotationally with respect to the shaft.

Abstract: A down-the-hole hammer includes a piston movably disposed in a casing and a percussion bit at an end of the casing. The percussion bit includes an integral bit and shank and a pilot removably fastened at a forward end of the bit. A method of enlarging a preexisting hole is also provided.

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: A coated high strength stainless steel strip product with a dense and evenly distributed metallic layer on one side or both sides of said strip is provided. Said layer consists of essentially pure gold, copper, nickel, cobalt, molybdenum, silver, tin or tungsten or alloys of at least 2 of these metals, the thickness of said layer is preferably maximally 15 ?m, the tolerance of said layer is maximally +/?30% of the layer thickness, the Cr content of the steel strip substrate is at least 10%, and that the layer has such a good adhesion so that the coated steel strip can be uniaxially stretched to fracture by tensile testing without showing any tendency to peeling, flaking or the like. The metal-coated strip product is suitable for use in applications that are load carrying and is able to transfer electrical currents to a contacting surface without an electrical conductivity drop at the interface between the surfaces.

Abstract: A cutting tool and a method for the production of cutting tools for metalworking characterized in that the holder body of the tool first is submitted to a surface hardening that results in the formation of compressive stresses in the surface and then submitted to a surface treatment that gives additional contribution of compressive stresses in the surface. In this way, it is allowed to, on one hand, be able to modify/machine or remove parts of or the entire phase-transition layer obtained in the surface hardening at the same time as additional compressive stresses are built up in the surface of a hardened steel material in the tool body.

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: 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: A copper base alloy, which is resistant or immune to carburization, metal dusting and coking, and resistant to oxidation, the alloy having the following composition (all contents in weight %): Al >0-15 Si 0-6 Mg 0-6 one or more of the group of Rare Earth Metal (REM), yttrium, hafnium, zirconium, lanthanum, cerium) up to 0.3 wt. % each; Cu balance; and normally occurring alloying additions and impurities. Related articles of manufacture and methods are also described.

Abstract: A tool head, which is adapted to receive a cutting insert for chip removal machining, includes a basic holder which has a lower support part and an upper clamping portion defining therebetween and insert-receiving pocket. A slot extends through the basic holder at a location spaced from the pocket, wherein the clamping portion is joined to a remaining portion of the basic holder by a hinge portion about which the clamping portion is elastically displaceable toward the cutting insert. A recess extends through the basic holder parallel to the slot and in communication therewith for receiving a nut roll. A clamping screw extends through a bore of the basic holder and into engagement with the nut roll, wherein the clamping screw is operable to displace the nut roll into the slot to expand the slot and thereby elastically displace the clamping portion about the hinge and toward the cutting insert.

Abstract: A rotary cutter includes a hollow rotary mantle having a cutter arbor on an outer periphery thereof, through holes extending radially through the mantle, and an air distribution mechanism. The air distribution mechanism includes first and second parts. The first part is affixed to the mantle coaxially therein for rotation therewith. The second part is arranged inside the first part, wherein the first distribution part is rotatable relative to the second distribution part. The first and second air distribution parts define air passages for communicating selective ones of the through-holes of the mantle with an air source in response to relative rotation between the first and second distribution parts.

Abstract: A rotor of a vertical shaft impact crusher includes a vertical rotor wall segment having a first wall portion being substantially tangential in relation to the rotor and a second wall portion being angled in relation to the first wall portion. A tip holder for mounting at an outflow opening of such a rotor includes a holding part for holding a wear tip. A fastening mechanism is attached to the holding part. The fastening mechanism is adapted to extend along the first wall portion and through the second wall portion from one side thereof. A fixing mechanism is detachably fixable to the fastening mechanism at the other side of the second wall portion.

Abstract: A tool body includes an insert seat for receiving a cutting insert for chip-removing machining. The insert seat includes a bottom surface and support surfaces upstanding from the bottom surface. Each support surface comprises at least three ridges separated by grooves. Each groove has a depth greater than zero and no greater than 0.015 mm. An insert mounted in the seat by a screw has a center hole whose axis is offset from the axis of a threaded hole of the body in which the screw is connected. That offset distance creates a prestress of the insert toward the ridges. The depth of the grooves (i.e., the height of the ridges) is substantially less than the distance of the offset.

Abstract: A drill for chip removing machining, including a front tip including at least one cutting edge and a chip flute. The chip flute is countersunk in an envelope surface of a body of the drill and extends rearwardly from the cutting edge. The chip flute is generally defined by a cross-section-wise concavely vaulted surface located between first and second longitudinal borders, the first longitudinal border extending from an area of a peripheral end of the cutting edge. The chip flute is deeper in an area of the first longitudinal border than in an area of the second longitudinal border such that a curve defining the cross-sectional shape of the flute surface has a radius of curvature that is smallest in the vicinity of the first longitudinal border and that increases towards the second longitudinal border. The flute surface transforms into a planar chip surface, which in turn transforms into the cutting edge.

Abstract: A percussion device for a rock drilling machine or the like, which comprises means for providing an impact, i.e. a stress pulse, to a tool connected to the percussion device. The means for proving the stress pulse include a stress element (4) of liquid, which is supported to a body (2) of the percussion device and means for subjecting the stress element to pressure and correspondingly for releasing the stress element (4) abruptly, whereby the stress energy is discharged as a stress pulse to the tool in direct or indirect contact with the stress element.

Abstract: A tool head, which is adapted to receive a cutting insert for chip removal machining, includes a basic holder which has a lower support part and an upper clamping portion defining therebetween an insert-receiving pocket. A slot extends through the basic holder at a location spaced from the pocket, wherein the clamping portion is joined to a remaining portion of the basic holder by a hinge portion about which the clamping portion is elastically displaceable toward the cutting insert. A recess extends through the basic holder parallel to the slot and in communication therewith, the recess receiving a nut roll. A clamping screw extends through the slot and into threaded engagement with the nut roll, wherein the clamping screw includes a conical head arranged to enter the slot for expanding the slot and elastically displacing the clamping portion about the hinge and toward the cutting insert.

Abstract: The invention relates to drilling or rockbolting machines, for the execution of underground works, in particular in mining operations. The carrier vehicle comprises a chassis and four wheels, all driving wheels, with two wheels situated on the right-hand side of the chassis of the vehicle and two other wheels situated on the left-hand side of the chassis. The four wheels are of the independent suspension type, having a jack-controlled height, and each comprise rotation-drive means, especially hydraulic motors. The chassis receives, at the front and at the rear, working equipment, such as drilling arms with respective guides, the basic position of which is horizontal and transverse to the direction of displacement of the vehicle. This carrier vehicle is applicable to the realization of a machine, which can be used in mine galleries of low height.

Abstract: A down-the-hole hammer includes a casing and a piston movable in the casing between a lowermost operating position and an uppermost operating position. A recess is provided between the piston and the casing so that the piston and the casing define an intermediate chamber between a top end of the piston and a bottom end of the piston. A passageway is provided between a source of pressurized fluid and the intermediate chamber such that, at all positions of the piston between the lowermost and the uppermost operating positions, the source of pressurized fluid is in flow communication with the intermediate chamber through the passageway. An opening in the piston at least partially defines the passageway.

Abstract: The present invention relates to a coated cemented carbide cutting tool particularly for turning applications with high toughness demands, of stainless steels of different compositions and microstructures, and of low and medium alloyed non-stainless steels. The cemented carbide is WC-Co based with a composition of 9-12 wt % Co, 0.2-2.0 wt % cubic carbides from elements from group IVa, Va or VIa of the periodic table and balance WC with a grain size of 1.5-2 ?m. The binder phase is W-alloyed with a CW-ratio in the range of 0.77-0.95. The coating includes a multilayered structure of the composition (TixAl1?x,)N in which x varies repeatedly between the two ranges 0.45<x<0.55 and 0.70<x<0.80, adding up to a total thickness of 2-9 ?m.