Abstract: A visual (or video) display unit of the raster scan type has a symbol memory, where the dot patterns of the available symbols are stored, and a refresh memory, where information is stored which identifies the symbols present on the image in question and their positions on the image. An auxiliary memory constitutes a simplified reproduction of the refresh memory, for example with 1 bit for each word in the refresh memory. For each symbol on the image in question, the auxiliary memory defines, on the one hand, the element in the image which is written first during generation of the image, and on the other hand a definition element. In the place in the refresh memory, which corresponds to the position of the definition element in the image, there is stored a code which identifies the symbol.

Abstract: A power loom for the manufacture of woven fabrics, in particular woven wire fabrics and felts for use in papermaking machines, is provided with a computerized pattern recognition system for monitoring the warp, the fabric, the edge of the fabric, the density of the weft, and so on. The device includes a video camera and computerized image processing means. By analyzing a picture taken near an edge of the fabric, digital information concerning the position of the edge of the fabric, the weft density, and so on, can be obtained. The digital information is adapted to be used in an open or closed control system for positioning the edge of the fabric in correct position, after an interruption of fabric through the loom, before a restart of the fabric feed. Digital information concerning the actual weft density can be utilized as the actual value in a weft density control system using the driving means of the warp beam of the loom as the executive members via a tensile stress control applied to the fabric.

Abstract: A fiber-optic sensor for measuring a physical quantity or sensing changes therein, consists of a transmitter and receiver unit respectively arranged to transmit and receive optical energy and an optical fiber for transmission of said optical energy to and from a sensor located at the measurement point. The sensor has at least one solid body, which is arranged to emit photoluminescent optical energy in at least one wavelength range, and a volume limited by at least two substantially plane-parallel surfaces, the separation of which is smaller than half the coherence length for either the transmitted or luminescent optical energy, whereby an interference pattern will differently affect the transmission of optical energy to the receiver unit as the optical length between said parallel surfaces changes with changes in the physical quantity being sensed.

Abstract: A fiber optical measuring device for measuring dynamic movements between a boundary surface of an optical fiber and a boundary surface of a movement-sensing body. The optical fiber is adapted to transmit optical energy to and from the boundary surfaces and at least one of the boundary surfaces includes a photo-luminescent material, the optical energy reflected from the boundary surface of the body being dependent on the relative position between the two boundary surfaces.

Abstract: In the manufacture of an article of ceramic material, for example a bladed turbine wheel of silicon nitride, there is first formed a plurality of article parts, at least one of which is a shaped powder body formed from powder of ceramic material mixed with a plasticizer, after which the plasticizer is driven off by a suitable heating operation. The article parts are then assembled together into a configuration conforming to that of the article to be manufactured, and the assembled article parts are surrounded with a gas-impermeable layer, for example a layer of glass. Finally, the assembled parts are isostatically pressed at elevated temperature to form the assembled article parts into a dense, homogeneous article.

Abstract: A platform for carrying electric high-voltage equipment, such as series-capacitors etc., is supported by insulator columns which are articulated at the upper and lower ends. Bracing takes place with the aid of diagonally-braced insulators which are connected together by means of ropes via a prestressed spring damper. The means provides a high damping and a low natural frequency in case of earthquake stresses. Through the prestressing of the spring damper, the platform will remain stationary at low loads such as wind loads.

Abstract: A device for transforming information in electrical form into optical form, where the optical information consists of light intensity, light polarization or spectral composition varying with time. The transformation of information takes place from electrical into optical form by means of optical modulators, e.g. liquid crystals, and the transformation from optical form into electrical form is arranged to be carried out with photo-detectors, the device comprising components to control or sense said optical modulators in one, two or three-dimensions with time, and to sense or control said photo-detectors.

Abstract: A DC arc furnace having a vertical arcing electrode adapted to be connected with a negative current lead and a hearth adapted to contain a melt below the electrode and having a hearth electrode, the hearth electrode extending laterally from the axis of the arcing electrode symmetrically with respect to the axis and having a plurality of electrical connections extending to the outside of the hearth and spaced laterally from the arcing electrode's axis symmetrically with respect to the axis, the connections being adapted for connection with a positive current lead and application of DC to the electrodes powering an arc between the arcing electrode and melt; wherein the improvement comprises a positive current lead below the bottom of the hearth and having an upper end positioned on the arcing electrode's axis below the hearth's bottom and extending from the positive current lead's upper end vertically downwardly on the axis to a low position where the magnetic field of the positive current lead cannot appreciab

Abstract: A hydraulic press with a pressure cell comprises a tray-shaped press plate with a bag-like diaphragm and a forming rubber pad and a press tray for a forming tool and a workpiece. The end wall portions projecting from the mid portions of each of the press plate and from the base of the press tray, provide thickness transitions which define a cavity in the operating position of the press tray. Between the press plate and/or the base of the press tray and the confronting force-absorbing surfaces of the yokes of the press frame of the press, play is provided in a portion above and below, respectively, the thickness transitions. This play allows the high stress levels which would otherwise arise at the thickness transitions to be reduced.

Abstract: A method for centrifugal casting involves mold rotation below the mean rotation speed during the casting and thereafter periodically varying the mold rotating speed so as to cause stirring throughout the wall thickness of the melt centrifugally held in the mold. This avoids the formation of snakes and blisters in the cast shape.

Abstract: The mold is rotated during casting while projecting at least one traveling magnetic stirring field tangentially into the melt so as to rotate melt to the mold speed.

Abstract: An optical sensor for detecting changes in physical quantities such as temperature, position, force, level, pressure, flow, acceleration, magnetic or electrical field strength or mechanical deformation, includes a luminescent material built up of atomically localized luminescence centers, included as a solid solution in an amorphous or mono-crystalline bonding material.

Abstract: An object is manufactured from a powdered material by isostatic pressing of a body, preformed from the powdered material, with a pressure medium, whereby the preformed body, in which at least the surface layer consists of a ceramic material in the form of a nitride, is surrounded by a casing which is rendered impenetrable to the pressure medium, before the isostatic pressing is carried out and the powder sintered. As the material in the casing there is used boron oxide or a glass containing boron oxide or a material forming glass while being heated, in which the content of boron oxide is sufficiently high for the glass--or the glass formed during heating--to be removable by water. The preformed body surrounded by the casing is subjected to a heat treatment for the formation of boron nitride on the surface of the preformed body, before the isostatic pressing is carried out. The casing is removed from the finished product by means of water or water vapor.

Abstract: A static convertor with forced commutation has at least one phase group connected between two busbars. The or each phase group has two series-connected branches with the point of connection therebetween constituting a phase terminal of the group. To the busbars there is connected a commutating circuit comprising commutating thyristors, commutating capacitors and commutating inductors common to the phase group(s). A two-terminal network, having inductive impedance at least at higher frequencies, is connected directly to the busbars and in operation a power flow between the two-terminal network and the convertor takes place. Since the network is connected directly to the busbars, the power flow does not pass through the commutating inductors and the convertor losses are minimized.

Abstract: A supervisory desk comprises a top section with a desk surface, or the like, a stand section with at least one leg of adjustable length which supports the top section so that the height of the top section above the stand section can be adjusted. The leg(s) is/are inclined (e.g. at 45.degree.) to the vertical plane, whereby ergonomic conditions are obtained for an operator using the desk having regard to the height of the desk surface, the leg space below the top section and the view over the rear edge of the desk surface.

Abstract: For bending the edge of a thick sheet of metal a tool comprising a yoke with a long and a short leg with plate-engaging bars in the opening between the legs is used. The tool is placed on a sheet so as to straddle the edge to be bent with one bar on each side of the sheet. An extensible member, for example a hydraulic cylinder, bears against the sheet to tilt the yoke so that the bars are pressed against the sheet to bend it. The tool may be provided with transport wheels and drive equipment for automatically moving the tool on the sheet.

Abstract: A method for stirring the unsolidified metal in the cast strand in continuous casting uses an asymmetrical multiphase stirring current with asymmetry caused by the phase angle of one phase of the current deviating from the phase angle of another phase of the current. In addition to the asymmetrical stirring, symmetrical stirring can be used at a location adjacent to the asymmetrical stirring so that the benefits of both types of stirring are obtained.

Abstract: A device for detecting metallic objects in a material flow, comprising as sensing member a scanning coil consisting of a primary coil and, for example, two oppositely connected secondary windings arranged symmetrically around the primary winding so that the voltage induced in the secondary winding becomes zero as long as no conducting objects appear in the scanning area. To eliminate irrelevant signals from conducting objects in the vicinity of the scanning coil but not in the material flow or from weakly conducting objects in the material flow, the primary winding is fed with at least two alternating currents having different frequencies. The corresponding secondary voltages are rectified in phase-controlled rectifiers, and in a calculating circuit the difference is derived between the output of one rectifier voltage and the output of another rectifier multiplied by a constant factor which includes the relation between the frequencies of the corresponding alternating voltages.

Abstract: A static convertor for power transmission by means of high-voltage direct current has a current regulator which influences the control angle of the convertor in dependence on the deviation between a current order supplied to the convertor and the present direct current of the convertor. The current regulator has a proportional part and an integrating part. The output signal of the integrating part is limited in the upward direction to a value corresponding to a maximum value of the control angle of the convertor. The output signals from the integrating and proportional parts are added to form the output signal of the current regulator. The limiting value of the integrating part is calculated by a calculating circuit as a function of the current order and the ideal direct voltage of the convertor. The calculation is made by determining the control angle at which, at a load current equal to the current order, the extinction angle becomes equal to the smallest permissible turn-off angle.

Abstract: An electromagnetically operated electric switch has its movable contact system attached in a contact carrier, which via rotatable arms is connected to two identical magnetic cores of an operating magnet. Both magnetic cores move along a line perpendicular to the contact movement, towards each other upon closing and away from each other upon opening. The cores are suspended from the stand of the electric switch by means of leaf springs which control the movement of the cores. The leaf springs may also serve as opening springs.