Abstract: A method for the manufacture of steel products and products thus produced, wherein steel is subjected to precipitation hardening in a martensitic structure subsequent to soft annealing and thereafter shaping. The method steps include shaping followed by solution annealing between 1200° C. and 1050° C., quenching from the solution annealing temperature with a quenching speed of at least 5° C. per second to a temperature below 500° C., subjecting said steel to an isothermal martensitic transformation and subsequently hardening the steel at a temperature between 450° C. and 550° C. to precipitate particles out from solution into said martensitic structure.
Abstract: A percussive drill for extension drilling includes a drill bit, a tube having a male screw thread attached to a female screw thread of the drill bit, and a rod having a male screw thread attached to a female screw thread of the tube. Central passages of the rod and tube are aligned with one another to conduct flushing fluid to the drill bit. The drill bit drills a hole whose diameter is from 60-170 mm and at least twice the outer diameter of the rod. A total area of a cross-sectional surface of the tube is within 100-125% of a total area of a cross sectional surface of the rod.
Abstract: Method for manufacturing tubes especially for fuel elements and tubes for construction of fuel rod skeletons made of zirconium-based alloy for nuclear reactors and a tube made thereby. The tubes are ground to a surface roughness of ≦0.2 &mgr;mRa with a belt device of SiC-based belts, so-called “dressed” SiC-based belts with cotton back or SiC-cork belts. The tubes may possibly be polished after grinding with a wheel to a surface roughness <0.25 &mgr;mRa.
Abstract: A tool tip and tool body assembly includes a tool tip having a first end for contacting a workpiece and a second end, the second end having a patterned surface of recesses and protrusions, and at least one through hole extending through the tool tip from the second end. A tool body has a first end having a patterned surface corresponding to the patterned surface of the tool tip for mating with the patterned surface of the tool tip, and at least one threaded hole adapted to align with the at least one through hole in the tool tip. At least one fastener having a threaded end and a securing end is provided, the fastener extending through the at least one through hole such that the securing end abuts against a surface in the at least one through hole, the threaded end mating with threads in the threaded hole. Torque is transmitted between the tool tip and the tool body solely by the at least one fastener and the patterned surface of the tool tip and the patterned surface of the tool body.
Type:
Grant
Filed:
December 14, 2000
Date of Patent:
February 25, 2003
Assignee:
Sandvik AB
Inventors:
Jörgen Eng, Sven Engstrand, Jonas Svensson, Anna Hedberg
Abstract: A grinding tool for grinding buttons of a rock drill bit includes a spindle having a longitudinal axis of rotation, and a grinding cup mounted on the spindle by a tongue-and-socket connection. A fastener in the form of a coil spring secures the grinding cup to the spindle. The grinding cup can be inserted into the inside of, or around the exterior of, the coil spring. When the spindle is rotated in a working direction, the spring tightens against the grinding cup. To install or remove the grinding cup, the grinding cup is rotated relative to the spindle in a direction corresponding to the working direction, whereby engagement between the grinding cup and the coil spring becomes loosened.
Abstract: A corrosion and oxidation resistant cemented carbide contains WC and 6-15 wt. % binder phase whereby the binder phase contains 8-12 wt. % of a corrosion resisting addition with an average WC grain size of 3-10 &mgr;m. Cemented carbide is obtained with selection of a total carbon content of 6.13−((0.05±0.007)×binder phase content in wt. %).
Abstract: A link for a tire chain including a tread portion and flanking side-wall portions with at least the tread portion including vertically extending links, three or four of which are interconnected by horizontal connectors to form a mesh of a desired shape. The link includes a base portion, a medial portion and a head portion, with at least one traction member of a material that is relatively harder than the material of the link partially embedded in the head portion and partially exposed on the surface of the head portion. The traction member may be in the form of tungsten carbide buttons or plates secured in holes in the head portion of the link or may be in the form of a plurality of particles consolidated in a cemented compact or steel matrix that is secured to the head portion of the link, either by being cast or formed on the head portion or by being provided on a body that is weldable to the head portion.
Abstract: A dense cemented carbide product is described. The product is manufactured from WC with a grain size between 0.1 and 0.4 ¼ 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 incrases and up to 100% increase in chipping resistance in PCB routing compared to conventional materials (6% cobalt and 0.4 ¼ m grain size).
Abstract: A gyratory crusher uses a new head nut attachment apparatus. The gyratory crusher has a shell, a shaft disposed within the shell, a mantle covering a portion of the shaft, a head nut located above the mantle, and a sleeve between the head nut and the shaft. The sleeve is maintained in position on the shaft by means of a tapered contact surface between the sleeve and the shaft, and the head nut is threaded onto the sleeve.
Abstract: A percussive rock drill bit includes a head portion with a forward surface surrounded by a peripheral surface. The peripheral surface supports a wreath of peripheral buttons. Front buttons are mounted to the forward surface inside the wreath of peripheral buttons. The button shave a diameter (D) and a height (H), wherein H/D<1.2. The buttons are welded to an essentially flat part of the forward surface whereby the buttons are metallurgically bound to the head portion.
Abstract: A down-the-hole percussive hammer for rock drilling includes a cylindrical casing and a drill bit disposed at a front end of the casing. The drill bit includes a forwardly facing cutting surface and a center longitudinal passage extending forwardly through a rearwardly facing rearwardmost end surface of the drill bit. The passage includes a rearwardly facing impact surface. A piston is mounted in the casing longitudinally behind the drill bit for reciprocation in a longitudinal direction. The piston includes a front portion sized to enter the center passage of the drill bit and strike the impact surface of the drill bit during each forward stroke of the piston. The impact surface of the drill bit is spaced forwardly from the rearwardmost end surface of the drill bit by a distance of at least ten percent of a total longitudinal length of the drill bit.
Abstract: A down-the-hole percussive hammer includes a casing, a drill bit attached to a lower end of the casing, and a reciprocable hammer for impacting against the drill bit. A top sub attached to an upper end of the casing includes a central passage for conducting operating air for actuating the piston. A feed tube is attached to the top sub and extends along a center axis thereof. The feed tube includes vertically spaced outlet and re-entry ports sealed from one another by a seal disposed inside of the feed tube. The outlet and re-entry ports communicate with a chamber formed in the central passage. A check valve is disposed at an upper end of the feed tube. The check valve includes an elastic sleeve arranged to overlie the outlet port and to be elastically biased away from the outlet port by pressurized operating air, whereupon the operating air passes out of the feed tube through the outlet port and then back into the feed tube through the re-entry port.
Abstract: The present invention relates to a lock cylinder including an outer cylindric block, an inner cylindric block, which defines a key hole, locking function members arranged inside the inner cylindric block, which are intended to cooperate with a key insertable in the key hole, as well as an activating member connected to the inner cylindric block. The inner cylindric block has such dimensions that it is displaceable inside the outer cylindric block, that members are arranged adjacent to the opening of the key hole to fix the inner cylindric block and the outer cylindric block in relation to each other in the axial direction, and a force-exerting member is provided, which applies an axial force to the inner cylindric block in a direction away from the opening of the key hole.
Abstract: A rock drill bit for percussive drilling, especially top hammer drilling, includes a bit head provided with front rock crushing buttons and a skirt. The bit head is provided with a number of grooves formed in the outside of the skirt and extending in the axial direction of the drill bit. Protruding lands are defined between the grooves, which likewise extend in the axial direction. Axially rearward ends of at least some of the lands are formed with retrac teeth. Each retrac tooth has a cutting edge extending along an outer circumference of the skirt.
Abstract: A method of manufacturing an as-cast composite roll by metallurgically bonding one or more rings of cemented carbide to a cast iron casing. The composite roll may be used for hot or cold rolling. The cast iron has the following composition in addition to Fe, in weight %, 1.9-2.8% Si, 0.02-0.10% Mg, 0.5-4% Ni, 0.1-1% Mn, balance Fe and a Ceqv=2.5-6.
Abstract: A rock-crushing rotary drill bit includes a body having a rock-crushing roller rotatably mounted thereon by bearings. The body includes a first flushing channel for conducting flushing fluid to flush the bearings, and a second flushing channel for discharging flushing medium outside of the bit body to flush away cuttings. The second flushing channel terminates in a discharge recess which defines a linear center axis. A nozzle is disposed at a downstream end of the discharge recess, and a valve element is disposed at an upstream end of the discharge recess. The valve element is spring-biased for closing the discharge recess, the valve element being openable against the spring bias in response to a sufficient pressure build-up of flushing medium within the second flushing channel. The valve element includes a guide structure for guiding the valve element for linear movement along the center axis of the discharge recess.
Abstract: A heat resistant austenitic stainless steel with high strength at elevated temperatures, good steam oxidation resistance, good fire side corrosion resistance, and a sufficient structural stability, suitable for use in boilers operating at high temperatures has a composition (by weight) of. 0.04 to 0.10% carbon (C), not more than 0.4% silicon (Si), not more than 0.6% manganese (MN), 20 to 27% chromium (Cr), 22.5 to 32% nickel (Ni), not more than 0.5% molybdenum (Mo), 0,20 to 0.60% niobium (Nb), 0.4 to 4.0% tungsten (W), 0.10 to 0.30% nitrogen (N), 0.002 to 0.008% boron (B), less than 0.05% aluminium (Al), at least one of the elements Mg and Ca in amounts less than 0.010% Mg and less than 0.010% Ca, and the balance being iron and inevitable impuities.
Abstract: A drilling tool includes a shaft having a front end to which a cutting body provided with cutting edges is detachably connected. In the front end of the shaft, a seat is formed which is delimited by spaced-apart protrusions between which there is a bottom surface. In the protrusion, there is a threaded hole for a screw, which when tightened applies pre-stressing forces to the cutting body. On the inside of the opposite protrusion, there is a supporting shoulder against which the cutting body is pressed when the screw is tightened and applies a lateral pre-stressing force to the cutting body. The protrusions are laterally displaced in relation to each other in order to freely expose the screw beside one of the protrusions.
Abstract: Molybdenum silicide material with high strength at both room temperature and high temperatures, comprising a composite material, which is made from a mixture including MoSi2 and ZrO2. The mixture includes 5-30 vol-% ZrO2 and 5-15 vol-% MoB, and the content of oxygen, in the form of SiO2 on or in particles of MoSi2, is below 0.5 weight-%. According to a further embodiment, the composite material comprises 3-35 vol-% SiC.