Patents Assigned to Asea Aktiebolag
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Patent number: 4386396Abstract: A self-commutated inverter has two alternately conducting main branches which, in series with each other, are connected to a d.c. voltage source. The point of connection of the main branches constitutes the phase terminal of the inverter and a turn-off circuit is connected to this connection point. Each main branch includes a commutating inductor at least one of which is provided with an auxiliary winding. The auxiliary winding is connected in series with diodes means and this series connection is connected to the d.c. voltage source for feedback of surplus energy in a commutating circuit and symmetrization of commutating capacitor voltage.Type: GrantFiled: December 8, 1981Date of Patent: May 31, 1983Assignee: ASEA AktiebolagInventor: Lennart Angquist
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Patent number: 4385878Abstract: An apparatus for granulating a metal melt which comprises a closed housing having a granulating section and a collecting section for the collection of manufactured powder, the granulating including a casting box and one or more primary nozzles which form decomposing, groove-shaped gas jets which impinge against the stream of metal melt falling from the casting box to form droplets which are then thrown in a parabolic trajectory into the collecting section. The apparatus further includes one or more secondary nozzles producing one or more auxiliary gas jets which are used to increase the breakdown or granulating effect of the groove-shaped gas jets, to control the trajectory of the formed droplets in the collecting section of the housing and to prevent the eddying of the formed droplets towards the primary nozzles from which the groove-shaped gas jets emanate.Type: GrantFiled: January 18, 1980Date of Patent: May 31, 1983Assignee: ASEA AktiebolagInventors: Hans G. Larsson, Erik Westman
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Patent number: 4382903Abstract: A method for granulating a metal melt wherein a tap stream of molten metal is granulated by directing a jet of gas having a trough-shaped cross-section against the side of the tap stream such that the tap stream is formed into droplets which are thrown into a parabolic trajectory. An additional gas jet is also directed towards the tap stream so that it hits both the trough-shaped gas jet and the tap stream, the additional gas jet acting to prevent the droplets of metal melt from moving towards the nozzle from which the trough-shaped jet of gas emanates. The nozzle which emits the trough-shaped jet of gas can thus be positioned very closely to the side of the tap stream without becoming clogged with deposited droplets of metal melt.Type: GrantFiled: February 23, 1981Date of Patent: May 10, 1983Assignee: ASEA AktiebolagInventors: Hans G. Larsson, Erik Westman
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Patent number: 4378978Abstract: The invention relates to a method of, and system for, degassing a mixture of a liquid first material, e.g. white water, and at least one second material, e.g. paper-making stock, the mixture being regeneratively pumped through cleaning means, e.g. a vortex cleaner, to an aeration tank. The regenerative pumping may be controlled to control the sub-atmospheric pressure applied to, and the liquid level in, the aeration tank.Type: GrantFiled: August 21, 1981Date of Patent: April 5, 1983Assignee: ASEA AktiebolagInventors: Nils E. Andersson, Sten Eriksson, Bengt Sinner
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Patent number: 4378496Abstract: The invention relates to a device for measuring current which traverses a light-emitting structure, the current passage thus causing emission of light. It is characterized in that the emitted light signal is adapted to be supplied to two photo-detectors having different sensitivity spectra and/or with at least one photo-detector being provided with an optical filter. The output signals of the photo-detectors are adapted to be supplied to a quotient forming member and/or a calculating member for obtaining a signal which is compensated for temperature variations in the light-emitting structure and other sources of error.Type: GrantFiled: October 22, 1980Date of Patent: March 29, 1983Assignee: Asea AktiebolagInventors: Torgny Brogardh, Olof Engstrom, Christer Ovren, Lars Sander
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Patent number: 4377835Abstract: In a thyristor valve having a plurality of series-connected thyristors, each thyristor has an individual recovery protection device arranged in its entirety at the potential of the thyristor. For each thyristor, the protection device comprises a voltage-sensing member whch indicates the point of time when the thyristor takes up reverse blocking voltage. A time-determining member defines a certain time interval, counting from said point of time. Control members are arranged to deliver a control pulse for firing the thyristor if the off-state voltage of the thyristor during the time interval exceeds a predetermined value.Type: GrantFiled: June 29, 1981Date of Patent: March 22, 1983Assignee: ASEA AktiebolagInventors: Gunnar Asplund, Lars Eklund, Bernt stlund
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Patent number: 4377780Abstract: For damping torsional oscillations of an electric a.c. generator, a speed-sensing member, for example a tachometer-generator, is connected to the a.c. generator. The speed-dependent signal generated by the speed-sensing member is supplied to a band-pass filter which is adapted to the natural frequency of the torsional oscillations. The output signal of the band pass filter is supplied directly to the control angle determining means of a converter connected to the generator. In this way, the power of the converter is modulated in such a way that the oscillations are damped.Type: GrantFiled: May 27, 1980Date of Patent: March 22, 1983Assignee: ASEA AktiebolagInventor: Hans Bjorklund
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Patent number: 4377834Abstract: In circuitry for generating tripping and blocking signals for the protection of electrical power supply network components as a result of the occurrence of faults, the blocking signals are selected from each phase of the electrical power supply network to prevent tripping in each phase for faults occurring behind the protected component. A sequence detector includes a partial detector for each phase of the electrical power supply network and includes logic circuitry responsive to respective tripping and blocking signals generated for each phase of the electrical power supply network in dependence on whether the fault lies ahead or behind the protected electrical component, respectively. Each logic circuit includes a gate and a delay circuit responsive to the output of the gate. The output of the delay circuit in the tripping logic circuit is input to the gate in the blocking logic circuit and vice-versa.Type: GrantFiled: June 1, 1979Date of Patent: March 22, 1983Assignee: Asea AktiebolagInventors: Leif Eriksson, Salomon Liberman
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Patent number: 4376890Abstract: A fiber-optic temperature-measuring apparatus which monitors the photo-luminescence of a body of solid material subjected to the temperature to be measured. Exciting radiation is conducted by means of at least one optical fiber towards a material with temperature-dependent luminescence which is in optical contact with the fiber, whereby luminescence occurs. The radiation emitted as a consequence of the luminescence is transmitted via at least one optical fiber from the body to a place of measurement, where a measure of the temperature may be obtained. The luminescent body may consist of a semiconductor material.Type: GrantFiled: October 6, 1980Date of Patent: March 15, 1983Assignee: Asea AktiebolagInventors: Olof Engstrom, Christer Ovren
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Patent number: 4375076Abstract: An electrical converter equipment for providing a d.c. voltage from an alternating current source. The converter has a unique operating cycle wherein a variable control angle is effected. The operating cycle for the converter comprises a series of half periods of the alternating current source. During different periods of time, the converter operates with different control angles. The control cycles comprise n periods of the input signal, where n is an odd number not less than three. During two half periods of a cycle, the control angle is varied. During two other half periods of the cycle, the converter operates at a fixed control angle. The half periods during which the converter is controlled with a variable control angle are time equidistant.Type: GrantFiled: April 9, 1980Date of Patent: February 22, 1983Assignee: ASEA AktiebolagInventors: Harry Magnusson, Gote Tallback, Ake Wennberg
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Patent number: 4371396Abstract: A method for manufacturing billets intended to be subsequently machined into a desired shape by plastic deformation, as by rolling, includes the heating to a predetermined bonding temperature of powder grains enclosed in a capsule, and subjecting the capsule at the bonding temperature to a high pressure sufficient to bond the powder grains together to form a substantially solid body. The capsule is inserted at the bonding temperature into an over-sized forming cavity of a press which includes relatively movable punches, the capsule being completely surrounded within the press by a layer of heat-insulating and pressure-transmitting solid material, such as talc or the like. Thus, when the capsule is subjected to the high pressure upon operation of the press, such material serves as a pressure-transmitting medium through which pressure is applied completely against all sides of the capsule.Type: GrantFiled: February 22, 1980Date of Patent: February 1, 1983Assignee: ASEA AktiebolagInventors: Hans G. Larsson, Erik Westman
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Patent number: 4370671Abstract: A semiconductor device comprises a semiconductor wafer arranged between metallic connecting members for supplying electric current to, and leading it from, the wafer, each connecting member having a substantially cylindrical external part. A ring of a sulphone polymer or of polyphenylene sulphide, which may be reinforced with glass fibre material, has portions of its internal peripheral surface surrounding and firmly engaged with the cylindrical parts of the connecting members, the ring and the connecting members forming a protective casing around the semiconductor wafer.Type: GrantFiled: February 13, 1980Date of Patent: January 25, 1983Assignee: Asea AktiebolagInventors: Gunno Eriksson, Anders Nilarp
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Patent number: 4367893Abstract: Gripping device (1), primarily intended for handling objects of circular cross-section such as shafts, round metal plates or rings with the aid of industrial robots. It comprises three parallel shafts (10a, b, c) with gripping arms with gripping members (11a, b, c). The shafts (10a, b, c) are rotatably journalled in a plane supporting member (2, 3). A drive motor (16) drives one shaft (10a). The other shafts (10b, 10c) are connected together with the driven shaft (10a) by means of gear wheels (14a, b, c), one on the driven shaft (10a) and one on either of the other two shafts (10b, 10c), and two racks (20a, 20b) in mesh with the gear wheel (14a) on the driven shaft (10a) and one of the gear wheels (14b, 14c) on the other shafts (10b, 10c).Type: GrantFiled: January 14, 1981Date of Patent: January 11, 1983Assignee: ASEA AktiebolagInventor: Arne Berg
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Patent number: 4365177Abstract: Gas-cooled rotor for a turbo-generator with air gap pick up. Each rotor slot comprises a conductor bundle with a large number of tangentially extending cooling channels, which are connected to an inlet chamber (17) on one side of the conductor bundle and an outlet chamber (18) on the other side of the conductor bundle. The conductors of the conductor bundle are fixed with respect to each other by means of a plurality of radial rods (8) embedded into the conductor bundle, and a small, radially inner portion and a small, radially outer portion of the conductor bundle are fixed in the tangential direction by means of an inner (12) and an outer (10) spacing device, respectively. The slot wedge member is provided with a plurality of substantially evenly distributed inlet channels (19) and intermediate, substantially evenly distributed outlet channels (21).Type: GrantFiled: March 17, 1981Date of Patent: December 21, 1982Assignee: ASEA AktiebolagInventor: Kristian D. Madsen
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Patent number: 4363653Abstract: Solid pieces of metal, such as steel scrap and ferrous pellets, are charged in a basin having a refractory inside and progressively melted down by an electric induction heater positioned above the basin and the charge. As melt collects in the bottom of the basin it is continuously or intermittently tapped into a storage container having heating means for keeping the melt molten. This prevents the melt level in the basin's bottom from rising uncontrollably.Type: GrantFiled: April 21, 1981Date of Patent: December 14, 1982Assignee: ASEA AktiebolagInventor: Staffan Granstrom
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Patent number: 4360084Abstract: A block brake assembly for a railway vehicle includes a holder for one or more brake blocks which, when the brake is engaged, are pressed against the periphery of the vehicle wheel. The holder comprises a pair of spaced side members, and the brake block or blocks have guide lugs and attaching lugs thereon projecting between the members. The blocks are retained against the holder by a leaf spring which is pivotally mounted at one end to the holder, projects through openings in the attaching lugs and bears against a lock pin on the holder at an opposite end thereof. A pair of stop elements on the holder bear against outer sides of a pair of the lugs for preventing tangential displacement of the block brake or brakes relative to the side members.Type: GrantFiled: August 27, 1980Date of Patent: November 23, 1982Assignee: ASEA AktiebolagInventor: Sven Stjerna
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Patent number: 4360864Abstract: A power converter includes a plurality of thyristors, each of which is controlled by a control circuit. A multi-section voltage divider is connected in parallel with a thyristor and provides the control circuit with power as well as means for measuring voltage across the thyristor. The present voltage divider components minimize the space required and cost of fabrication.Type: GrantFiled: November 12, 1980Date of Patent: November 23, 1982Assignee: ASEA AktiebolagInventor: Gunnar Asplund
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Patent number: 4358819Abstract: A static electrical converter equipment has a plurality of controllable converter bridges connected to a common a.c. supply source. Control pulse devices supply control pulses to the controllable valves of the bridges. The converter equipment comprises members arranged to prevent a control pulse from being supplied to a valve in one of the bridges, for initiating a commutation in this bridge, until a corresponding commutation in another bridge is completed.Type: GrantFiled: June 3, 1980Date of Patent: November 9, 1982Assignee: ASEA AktiebolagInventor: Lennart Sandberg
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Patent number: 4357509Abstract: An electric switch, for example a load switch or safety switch for low voltage, has at least one fixed contact member and two movable contact members, which form parallel current paths and which, in the closed position of the electric switch, are pressed against the fixed contact member on opposite sides thereof under the influence of contact pressure springs. Closing and opening are accomplished by means of a wedge-formed element which is displaceable between the movable contact members, said element being arranged on an operating member linearly displaceable between two end positions. The movable contact members are guided in the switch body in such a way that they move perpendicular to the direction of displacement of the operating member. The movable contact members are of elongated cross-section and have defined contact surfaces and break points.Type: GrantFiled: September 15, 1980Date of Patent: November 2, 1982Assignee: ASEA AktiebolagInventor: Bo Adlerteg
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Patent number: 4356340Abstract: A DC arc furnace has shielding between the arc and its power lines preventing or retarding the magnetic field created by the power lines from deflecting the arc.Type: GrantFiled: March 11, 1980Date of Patent: October 26, 1982Assignee: ASEA AktiebolagInventor: Sven-Einar Stenkvist
