Abstract: In visual display apparatus in which characters are displayed by modulation of a TV type raster on a cathode ray tube, the normally uniform spacing of the sweep lines of the raster is selectively modified to produce groups of lines having decreased spacing therebetween. The groups of lines are modulated to display rows of characters on the screen of the cathode ray tube. The spacing of the remaining lines between the groups is at the same time increased to provide a wider separation between the rows of characters thereby improving the aesthetic appearance of the display. Video modulation, synchronizing and control signals are obtained from a composite input signal. The control signals are utilized to operate a sweep modification circuit.

Abstract: There is disclosed a device for dewatering sludge such as residuals in sewage discharge processing installations. The device provides that cakes are formed of the sludge. These cakes have initially a high water content and are of non-homogenous, loose consistency. They are guided between filter bands through a preliminary filtering zone in which some of the water contained in the cakes is extracted by straining and pressure action applied thereto. The filter bands with the cakes therebetween are then successively guided over a first dewatering drum and a subsequent second dewatering drum. Pressure is applied to the filter band while being guided about the drums, thereby extracting further water from the cakes. Additionally, the cakes while traveling from the feed-in point toward and through pressure zones are deformed and also turned over thereby compacting the cakes as water is extracted therefrom. Finally, the cakes after being sufficiently dewatered and compressed are discharged.

Abstract: There is disclosed a device for dewatering sludge, sewage and other materials containing water and solid particles. The device comprises at least two rotatable and two superimposed power driven filter bands which are successively guided to and about the perforated cylindrical walls of the drums in pressure engagement therewith so as to drive the drums in opposite direction and causing release of water from sludge fed between the two filter bands. After leaving the last drum the bands are guided by rolls along a meandering path along which the sludge is repeatedly stretched and pressed to cause further release of water from the sludge and to discharge the now dewaterized sludge at the end of the path.

Abstract: In a cable or CATV system consisting of a central station with a television transmitter connected via a television transmission cable to a plurality of remote stations each with a television receiver, there is provided apparatus for signalling between the central and remote stations. The apparatus includes at the central station pulse generating means for transmitting via the cable variable sets of packets of first frequency signals followed by a packet of second frequency signal. Each of the remote stations is assigned a specific set of the first frequency signals. In each remote station the packets of first frequency signals are converted to a set of first pulses and the packet of second frequency signal to a second pulse. Counting means count the first pulses of the set and if the count at the time the second pulse is received agrees with a count assigned to the remote station an indication is given.

Abstract: Temperature-stable electret microphone with a metallized plastic film stretched over a polarized plastic film and fastened to an underlying fixed electrode, the polarized plastic film being on at least one side embossed with a relief pattern, having a smaller area than the underlying fixed electrode and being concentrically fixed to this by the metallized plastic film.

Abstract: Current pulse circuit for the supply of a well-defined current pulse to a ferrite core memory of the type where a desired current loop is set up by means of current gates according to a coordinate system. In order to reduce power loss and activation time the circuit is provided with a current regulator comprising a number of parallel-connected output transistors connected as emitter-followers. Base current is supplied to the output transistors by a driver circuit which is controlled by a control voltage received from a comparator circuit in correspondence with the difference between the momentary value of the pulse current and a target value produced by a reference source. The circuit may be further improved by the inclusion of an auxiliary current circuit in parallel with the output transistors, dimensioned to supply an auxiliary current which is equal to or less than the target value.

Abstract: A device for locking an insert in a support having a receiving hole or sealing a tubular member such as a pipe, consists of a somewhat bottle-shaped bushing having a cylindrical collar or bushing portion, and a conical portion secured at its narrow end to said collar, an inside screw thread, and a locking ring seated on the cone adjacent to the collar. The dimensions of the collar section of the bushing, the cone and the locking ring are so correlated that bushing and locking ring fit the cross-section of the hole with slight friction when the insert is placed in the hole. Locking of the insert in the hole is effected by inserting a screw bolt or screw tightening means into the insert coaxial therewith. This causes lifting of the insert which in turn effects spreading of the locking ring thereby pressing the same against the wall of the hole.

Abstract: A linearizing circuit is described which gives a nonlinear relation between an input and an output signal of the circuit. Such a circuit can be used to compensate for the nonlinearity in, for example, a frequency modulator. The circuit includes a nonlinear element, preferably a PIN-diode connected in a voltage divider to provide a biasing current to the element. An attenuating and an amplifying circuit are connected to the input and to the output, respectively, of the circuit. By varying the values of the attenuation/amplification and the value of the operation point of the element, the nonlinearity of the circuit can be varied.

Abstract: A method and apparatus for manufacturing a spiral member by cold working an elongated strip comprising attaching one end of the steel strip to a mounting plate on a rotatable axle and driving the axle in rotation to wind the strip onto the axle to form a spiral member from the strip. The strip is guided as it proceeds for winding on the axle by two spaced guide plates on opposite sides of the strip so that each turn of the strip will lie adjacent the previous turn. The position of the guide plates is adjusted with respect to the winding of the strip along a line which forms an angle with respect to the axis of rotation of the strip. After the formation of the spiral member, it is drawn to a predetermined length.

Abstract: In a magnetic-disc data storage device using exchangeable discs for the recording of data on circular tracks, a reference track is provided on the disc and during interruptions in the transfer of data, a read-write head is moved to the reference track and the error in its expected position, due to dimensional changes in the disc or the storage device or due to misalignment of the head, is measured. In subsequent data tracks access the position of the head is corrected by error measured so that the head is correctly aligned with the selected data track. Measurement of the error is carried out more frequently when the error is changing rapidly.

Abstract: In order to fix the position of two printed wiring connectors located on the same circuit board an attaching bar is used. This bar is laid over the connectors and is provided with positioning pins adapted to engage the attachment holes of the connectors. The bar is provided with mounting studs having mounting holes at some distance from the edge of the card so that corresponding holes in the card will not weaken the edge.

Abstract: A package of a hose of flexible material which comprises a succession of folded sections of flexible hose material superposed on one another to form a package having an inner section with an inner surface and an outer section with an outer surface. The folded sections between the inner and outer sections have the same axial length. The sections gradually increase in circumferential extent from the inner surface to the outer surface. Each section has a foil length of the same initial circumferential extent so that the sections are progressively expanded from the inner surface to the outer surface. The inner surface is of four-pointed star shape such that the folded sections are stretched over the points of the star to lie against one another at the points of the star while the outer surface is formed as a quadrangle with corners at the points of the star.

Abstract: A compensation network for a passive filter which compensates for the variation of the loss attenuation of the filter dependent on ambient temperature variations consists of an L-section whose series arm is formed by a temperature dependent resistor and whose shunt arm is formed by another temperature dependent resistor in series with a resonant circuit. The resonance frequency value of the resonant circuit is chosen nearly equal to the band limit frequency of the filter.

Abstract: A switch actuating device for a telephone instrument of the one piece type comprising actuating means protruding through the base portion of the instrument for actuating the off-on switch when the instrument is removed from or put on a table surface. Said projecting actuating means comprises along a peripheral outline of said base portion distributed parts, each of which cooperates with an element which actuates the contact springs of the switch. Said element is symmetrically constructed and comprises two links and two arms. The links are turnably mounted in bearings, are spring actuated and are at their ends actuated by the said actuating means.

Abstract: There is disclosed a ski pole provided with a disk mounted at one end above the tip of the pole and a handle grip at the other side of the pole. At least one scraper part projects from the disk to clean the skis, the soles of ski boots and other objects having a flat surface to be cleaned.

Abstract: A cross-point array for telecommunication systems, produced as an xy-matrix in a monolithic substrate with switching means arranged at the cross-points between the x and y conductors in the form of transistors controllable to assume an "on" state with a low impedance and an "off" state with a high impedance, the transistors having their collector-emitter path connected between the x and y conductors and supplied with current from a constant-current generator, is improved by having the collector-base diode of each transistor connected in parallel with a Schottky-diode supplied with current from a second constant-current generator and operating in its forward direction in the "on" state, whereby cross-talk caused by a parasitic transistor function is inhibited between the cross-points in the substrate.

Abstract: A device for pressing out pliable and/or pulverized material in the form of a strand comprising a matrix supported by a matrix pan which can be lifted relative to the container for the material to be pressed out whereby the matrix can be easily detached for cleaning and other services. The length of the matrix relative to the pressure table is such that the emerging strand can be checked directly at the discharge end of the matrix and be easily and accurately cut into sections by a cutting device.

Abstract: Aluminum wire, of either pure aluminum or an aluminum alloy is plated with a firm layer of nickel by passing the wire through a pickling bath of an aqueous solution of phosphoric and hydrochloric acids at a temperature of between 50.degree. and 70.degree. C and then electroplating the wire with nickel.

Abstract: A data processing system is disclosed in which a store has a plurality of pairs of storage locations. An indicator is provided for each location pair to indicate which location of the pairs is to be used for read and write accesses. The indicators are each set to indicate that after a write access to a pair of locations, read accesses are to take place to the location of the pair currently indicated for write accesses and periodically, for example at the end of a sequence of instructions, the indicators are set to indicate that write accesses are to take place to the opposite location of the pair to that which is currently indicated for read accesses.