Abstract: Melt fed to a continuous casting mold is slowed and spread by a magnetic field acting in the path of the inflowing melt stream. The magnetic field, which is either a static field powered by continuous current, a field powered by permanent magnets, or a field powered by low-frequency alternating current, is applied at at least two spaced-apart locations, either in two separated cast strands or at spaced locations across a wide single strand.
Abstract: The central unit of a computer equipment has a processor and a memory as well as redundant units as backup units for the processor and/or the memory. Further, there are members for changeover from an active unit to a corresponding backup unit in the event of a fault in the active unit. The central unit has interrupt routines and carries out write and read operations against the peripheral units of the equipment. A bumpless changeover from an active unit to a backup unit is obtained by establishing rollback points (P.sub.0 -P.sub.4) in the program execution by storing the processor state and the memory content in at least all hardware initiated interrupt routines; by logging all operations against the peripheral units after each rollback point; by returning the program execution, after a changeover (at P.sub.f) to a backup unit, to the last established rollback point (P.sub.
Abstract: Expansive forces in a furnace of cylindrical shape (e.g. a ladle furnace) are absorbed by means of a metallic ring positioned in the bottom of the furnace which substantially fits the inner, lower side wall of the cylindrical steel shell of the furnace and absorbs the expansive forces directed against this side wall.
Abstract: Generator rotor for a turbo-generator in which the rotor winding is fed via two feeding conductors, which are each arranged in a bored channel in the rotor body. The two channels diverge in relation to one another and each channel is bored in part in an axial shaft portion of the rotor body and in part in the slotted rotor portion of the rotor body.
Abstract: A control system for a programmable industrial robot has a joystick for manual control of the robot during programming for teaching the robot to follow a working path defined by a number of set points. The control system further comprises a memory for storage of the coordinates of these set points and of other instructions and control members for control of the function of the control system during the programming and for storing or entering instructions in the memory. The control members comprise a group of control members each having a plurality of different functions, the particular function in question being determined by the prevailing condition of the control system. An indicating member is arranged, for each of the control members in the group, to indicate the current function of said control members.
Abstract: The present invention relates to a fiber-optic measuring apparatus for measuring physical quantities, such as position, speed, acceleration, force, pressure, elongation, temperature, etc., comprising at least one optic fiber for conducting light between an electronic unit and a transducer. The transducer comprises a member having at least one luminescent material, and the position of that member with respect to the fiber end is influenced by the quantity being measured, the output signal from the transducer thus being dependent on the quantity being measured.
Abstract: A synchronous machine having a rotor with a plurality of salient poles which are supported by a rotor rim. The rotor rim is arranged by means of a hollow annular device in mechanical connection with a rotor hub, cooling gas flowing into the annular device relatively close to the hub and leaving at the rotor rim, flowing through cooling ducts in the rotor and stator, through a cooler and out into a cooling gas space which includes a plurality of guide vanes arranged so that the cooling gas on its way from the cooler to the hollow, annular device passes through the guide vanes and is thus put in rotation around the axis of rotation of the rotor.
Abstract: The invention relates to a device for heating billets, strip or sheet-metal, the device including one or more inductive edge heaters to heat the edges of a billet on its way from a continous casting machine, or strip or sheet-metal coming from a hot-rolling mill, arranged to surround the outer parts of the edges in order to heat them. The induction heater(s) comprises(s) one or more flat spiral element(s) (1) bent around the side edges of the billet, etc, and also at least one vertically placed, flat coil (4), located substantially parallel with the side edge (5) of the billet, etc.
Abstract: In strip casting, a melt is pressed between a travelling belt and a casting drum rotating along with the belt. A method and device for measuring the speed difference between the speed of the belt and the peripheral speed of the drum involves providing the belt on one side with a pattern of alternately darker and lighter stripes. Around the periphery of the casting drum there is arranged a number of measuring zones, each having the same width as that of the stripes. Each measuring zone includes a transducer built up of a number of photocells which, via optical conductors opening out to the measuring zones, can be activated by the stripes. When, during a casting operation, a measuring zone has arrived at a given measuring region, the number of activated photocells is read. The same procedure is repeated when the same transducer arrives at the end of the measuring region.
Abstract: An industrial robot supports an operating member mounted on the robot hand for carrying out work or monitoring operation on an object. The robot has a sensor which controls the path of movement of the robot hand during the operation. The robot is provided with means which during the work operation investigates whether a quantity, sensed with the aid of the sensor, for example a sudden change in the direction of the path, fulfills a predetermined criterion and, in dependence thereon, interrupts the movement of the robot hand if the criterion is fulfilled.
September 16, 1987
Date of Patent:
May 16, 1989
Bjorn Andersson, Mats Bjorkelund, Stefan Edstrom, Jan Fager, Monica Schofield
Abstract: A magnetoelastic force transducer is made of two identical, cylindrical bodies of magnetic material which are held together by means of a stud bolt. In an axially extending and concentrically located inner space there is placed a bobbin with two measuring windings, connected in opposition, and an excitation winding supplied with alternating current. The interior of the transducer is shaped such that a thin cylindrical tubular wall is formed immediately opposite to the respective measuring winding in each one of the bodies. When the transducer is force-loaded via the stud bolt, a compressive stress arises in one of these tubular walls and a tensile stress arises in the other tubular wall. This influences the magnetic conditions such that a signal is obtained from the measuring windings which is proportional to the applied force. In order to eliminate a possible measuring signal at zero applied force, means is provided to move the bobbin in the axial direction.
Abstract: The switching device has a contact arm which is fixed on a shaft in the form of a thick-walled tube and is turnable between a closed position and an open position under the influence of a torsion rod spring. At one of its ends the spring is fixedly connected to the contact arm and at its other end to a percussion hammer. In the closed position the spring is arrested in tensioned condition by means of a latch. When releasing the latch for opening of the switching device, the spring energy is transformed to rotation energy in the hammer and is transferred to the shaft by impact against a projection on the shaft. In this way the contacts of the switching device immediately attain a great separation velocity.
Abstract: An industrial robot has a position controller for each one of the axes of the robot and a computer for control of the robot. The computer continuously determines, with the aid of a mathematical model set up in advance, in dependence on the robot configuration and load in question, the mass moment of inertia of the axes, the coupled mass moment of inertia, and the moment caused by gravity. From the relationships between acceleration/deceleration and the drive motor torque for the different axes, the maximum available acceleration/deceleration for the axis is determined while assuming that maximum motor torque prevails for each axis. For each axis this value is compared with the maximum acceleration/deceleration value that may be allowed from the point of view of stability. On the basis of the lower of these values, optimum gain is determined and set in the position controller and/or a path planning parameter.
September 29, 1987
Date of Patent:
April 4, 1989
Sven Jonsson, Erik Persson, Lars stlund
Abstract: An industrial robot has a sensor mounted on a hand of the robot which senses the position of an object relative to the sensor. The sensor controls, during automatic operation of the robot, its movement in relation to the object, a robot control system determining the path of the robot in a robot coordinate system on the basis of measurement signals from the sensor. For calibration of the sensor, the sensor is automatically moved to a number of points connected to a calibration object with a known position in the robot coordinate system. At each point a number of measurements of the position of the object in relation to the sensor are made. On the basis of the measurements, those transformations are determined which transform the measurement signals of the sensor to the position of the measuring point in the robot coordinate system.
Abstract: A coil for arrangement in slots in a stator or rotor of an electrical machine, in particular a high voltage coil, comprising a bundle (17) of a plurality of conductors (18) located adjacent to each other and provided with a conductor insulation (19) for insulation of the conductors from each other as well as a main insulation (14) surrounding the bundle for insulation of the bundle against the machine slot. The main insulation consists of a wrapping of a tape- or sheet-formed insulating material wound in several layers around the bundle and comprising a layer with small mica flakes which, as well as the spaces between layers of mica flakes in the wrapping, contains a cured impregnating resin. At least that part of the impregnating resin located in the spaces between mica layers contains particles of a filler with an intrinsic thermal conductivity of at least 5 W/mK, such as aluminium oxide or boron nitride, and with a grain size of the particles of 0.1-15 .mu.m in at least 90 percent of the filler.
September 25, 1987
Date of Patent:
February 21, 1989
Arne Hjortsberg, Goran Holmstrom, Thommy Karlsson
Abstract: The bending and turning movements of the wrist are brought about by drive motors via at least one gear train, in which a cylindrical gear pinion drives a cylindrical gear wheel via an intermediate wheel. For adjusting the backlash, the intermediate wheel is journalled on a movable support which makes contact with a cylindrical guide surface in the wrist housing and can be displaced, by means of two adjusting screws, along a circular path, the center of which coincides with the axis of rotation of the gear pinion. The intermediate wheel is journalled on an eccentric bearing pin on the movable support.
Abstract: The wrist is built up of two wrist halves, between which the tilt with the turning disc is journalled. Each wrist half comprises an intermediate gearing with conical gear wheels and is built together with a drive motor. The two wrist halves are identical, and each half constitutes an individual trimmable drive unit for turning the tilt and the turning disc, respectively.
Abstract: A magnetoelastic force transducer is made of two identical, cylindrical bodies of magnetic material which are held together by means of a stud bolt. In an axially extending and concentrically located inner space there is placed a bobbin with two measuring windings connected in opposition and an excitation winding supplied with alternating current. The interior of the transducer is shaped such that a thin cylindrical tubular wall is formed immediately opposite to the respective measuring winding in each one of the bodies. When the transducer is force-loaded via the stud bolt, a compressive stress arises in one of these tubular walls and a tensile stress arises in the other tubular wall. This influences the magnetic conditions such that a signal is obtained from the measuring windings which is proportional to the applied force.