Abstract: A reloadable ribbon cassette system for typewriters or office machines of similar construction employs a housing which receives an exchangeable supply spool for the ribbon and an exchangeable take-up spool core. To facilitate the reloading process, the take-up spool core is mounted in the housing on a bearing pin which extends upward from a contact surface. The take-up spool core has a bearing bore into which the bearing pin extends and a bearing surface which rests on the contact surface. The contact surface is disposed closely below a receiving bore in the take-up spool core which accommodates a fastening element attached to the end of the ribbon.

Abstract: A type face striking system for striking a type face to produces an imprint on a record carrier in a writing machine, the system including; an electromagnetically actuatable printing hammer movable under the influence of an electrically generated magnetic field between a rest position and a striking position for striking the type face; an actuating device including a magnetic field producing means in the form of a conductor coil connected for receiving an operating voltage for producing the electrically generated magnetic field; and a control unit connected to the coil and operative for successively applying thereto: a voltage pulse of a first polarity for causing the actuating device to produce a magnetic field which effects movement of the hammer from its rest position to its striking position; and a voltage pulse of a second polarity, opposite to the first polarity, for causing the actuating device to produce a magnetic field which effects movement of the hammer from its striking position toward its rest p

Abstract: A plotting device for typewriters or office machines of similar construction which comprises a motor driven carriage; a record carrier; a print head; a ribbon in a cassette; a reversible, controllable drive motor for moving the record carrier up and down; the motor driven carriage being movable along the record carrier; the ribbon being housed within the carriage with a portion of the ribbon extending outside of the carriage for being contacted by the print head; the print head being operatively connected to the carriage so that the print head can strike the ribbon and produce a full set of alpha-numeric characters on the record carrier; an X-Y plotting mechanism equpped with styli and being disposed on the cassette; and a control system for moving the styli from a detent position into an operating position with respect to the record carrier.

Abstract: An end-of-ribbon sensing device for an office machine, which machine includes a printing station for receiving a nonreusable ribbon which is displaceable through the printing station and which has a scannable marking at its trailing end.

Abstract: A microprocessor control system is provided for a steel wheel vehicle having at least two propulsion/braking units. Each unit operates a truck having a pair of axles each with two steel wheels. A propulsion/braking control includes a microprocessor that applies current commands to respective chopper controls that operate the axle motor drives. Braking command signals operate the associated braking system to apply dynamic and/or friction braking in the braking mode.

Abstract: A process of frame-to-frame prediction coding in which a frame is broken down into a regular block scanning field of n x n pixels and then prior to each prediction, up to four prediction methods, namely (1) block-by-block displacement vector calculation, (2) object-related displacement vector calculation, (3) nullification of the displacement, and (4) nullification of the prediction, are monitored as to the data rate to be transmitted, and the prediction method that leads to the smallest prediction errors is selected for the transmission.

Abstract: The invention relates to an apparatus for the electrochemical processing of workpieces. The apparatus comprises a processing electrode (2) adjustable in relation to the workpiece (1) and a supply unit (3) for the electric working value supplied to the workpiece (1). The store (8) comprises in the form of digital measured values the course in time during processing of the working value detected by a measuring system (5). In a comparison stage (7) the stored course in time of the working value, serving as a required value, is compared with the course delivered by the measuring system (5) (actual value), and a control signal is delivered to the supply unit (3) when a given difference between the required and actual values is exceeded.

Abstract: Several line drawing devices to permit drawing horizontal and vertical lines on typewriters are known. The fact that they are rarely encountered in practice, should be sufficient proof that they were not found to be satisfactory and greatly impede the typing process. These drawbacks are overcome by the invention in that the ribbon cassette is provided with a receptacle for a colored writing implement which, in one end position, resiliently rests on the record carrier so as to produce drawn lines and is arranged to be movable and arrestable in another end position to put it out of operation. A significant advantage resides in the fact that the colored writing implement can here be attached to the cassette at a location where the typing process is not interfered with. The colored writing implement can easily be exchanged by removing the ribbon cassette. The ribbon cassette together with the colored writing implement permits easy production of drawn lines in the horizontal, vertical or any other direction.

Abstract: The invention refers to a process for regenerating electrolytes containing sodium nitrate for use in the electrochemical working of metallic workpieces within the pH range from 4 to 12.Iron (III) nitrate is added to the electrolyte in the working cycle in such an amount that the hydrolysates are predominantly precipitated in coarse flocculent form. Flocculents may be added to the electrolyte.

Abstract: The apparatus relates to an excess-current monitoring device in a direct-current generator having a controlled rectifier, and is particularly useful for electro-chemical machining. A reference signal is generated by a signal generator in accordance with the voltage drive of the rectifier and the mean current supplied to the load. The reference signal is supplied to a comparator which supplies a current-switch-off-signal when the value of the reference signal as compared to the instantaneous load current indicates excess mean load current. This enables optimum machining.

Abstract: The invention relates to a phase-adjusting device for the inverter, having controllable semiconductors, of a parallel-resonant circuit frequency converter. The phase-adjusting device, operating on the PLL principle, compares a signal derived from the inverter output voltage and a signal delayed by a predetermined amount in relation to the control pulses of the oscillator 1 to a phase-comparing stage. In dependence on the phase comparison of the two signals, the oscillator frequency is so adjusted that the inverter output voltage and the inverter output current are in phase.

Abstract: An optical cable composed of a common sheath and a plurality of elongate basic elements enclosed by the common sheath, each basic element being composed of a stable sheath and at least one optical fiber housed and loosely guided in the stable sheath, and the plurality of basic elements being assembled together to form a plurality of basic units each of which is composed of several basic elements and is deformable transverse to the length of the basic elements. The plurality of basic units is assembled together to form at least one cylindrical layer of the cable, with each basic unit in the circular layer having a noncircular cross-sectional configuration which is flattened in the radial direction of the cable, while the stable sheaths of the basic elements are not significantly deformed, as a result of a deformation pressure exerted radially inwardly on the circular layer.

Abstract: A process is disclosed for producing an optical fiber comprising forming a tubular glass body having at least one doped layer, at least one concentric layer, each layer having a different index of refraction, and a hollow center. The glass body is heated until the softening point is reached, and is then drawn into a glass fiber. During drawing, a partial vacuum is maintained in the hollow center of the tubular glass body, the partial vacuum being of sufficient magnitude to reduce the evaporation of doping material from the interior of the tubular glass body and thereby effectively prevent a reduction in the index of refraction in the center of the optical fiber.

Abstract: A process is disclosed for making a preform from which optical fibers may be drawn, comprising forming a tubular glass body having a hollow center and concentric layers, at least one layer being a doped layer, and each layer having different indices of refraction. A partial vacuum is formed within the interior of the tubular glass body, at least part of the glass body is softened by heating, and the softened portions of the tubular glass body are collapsed to form a preform. The pressure of the partial vacuum is selected to effectively eliminate a dip in the index of refraction of any glass fiber drawn from the preform.

Abstract: The invention relates to a process and an apparatus for the electrochemical etching of grooves of very small width, in particular smaller than 1.0 mm, into a workpiece. Etching is performed with a wire electrode or a rod electrode extending across the etching direction. In order that the electrolyte liquid introduced into the work gap does not flow away uncontrolled, but fills out the work gap over the entire working length of the electrode, a baffle acting behind the rear of the electrode is provided. This ensures that the flow of the electrolyte takes place essentially in the work gap and in the longitudinal direction.

Abstract: The invention relates to a circuit for indicating faults in a current consuming load connected to an electronic switching device by means of an indicator device wherein the input of the electronic switching device receives a signal via a control line to cause the load to be switched on. The problem of reducing the number of lines leading to a central operating location is solved in that the input resistance of the electronic switching device is made to be variable by means of an impedance which is controlled by an error signal and the indicator device is actuated in dependence on the current flowing in the control line and emits a fault indication if the current in the control line deviates from the value which it has when there is no fault.

Abstract: An apparatus for spark-erosive planetary eroding of a workpiece in which an eroding electrode is lowered into the workpiece as the workpiece is eroded and the workpiece and electrode carry out planetary motion with respect to each other so the operation gap between the narrow periphery of the electrode and the workpiece moves around the periphery of the electrode during planetary motion. A plurality of injection nozzles are positioned around the gap for supplying liquid dielectric thereto in accordance with the planetary movement. A plate having bores therethrough closes a chamber containing such liquid with each bore supplying a nozzle. The bores terminate at a wall of the chamber so that the opening into the chamber and therefore the supply to each nozzle is varied in accordance with the planetary movement.

Abstract: An inverter circuit with a thyristor bridge circuit, a load circuit developed as a parallel oscillating circuit connected to the bridge circuit, an impulse generating circuit for supplying ignition pulses to the bridge circuit and an arcing time regulating circuit for controlling the impulse generating circuit in accordance with the arcing time. A down-and-up integrating circuit is triggered by an ignition impulse to integrate down until a discriminator circuit produces a signal indicating zero crossover of the load current, thereafter to integrate up until a second discriminator produces a second signal indicating zero crossover of the load voltage, at which time the integrator output indicates arcing time, and is applied to the time regulating circuit to control the impulse generating circuit.

Abstract: A rotor rotating device connected to an oil supply system for turning the rotor of a rotary machine, which rotor is fitted with a gear wheel, the device including: a hydraulic motor; a hub mounted to be rotated by the motor; a pinion mounted on the hub and dimensioned to mesh with the gear wheel; a screw shift drive operatively associated with the pinion for permitting movement of the pinion in the direction of the axis of rotation of the hub between a first position in which the pinion is disengaged from the gear wheel and a second position in which the pinion meshes with the gear wheel; a compression spring disposed to urge the pinion toward the first position; and a piston connected to the pinion and arranged to be actuated by oil under pressure from the oil supply system for moving the pinion into the second position.

Abstract: An apparatus for measuring and monitoring the angular velocity of the shaft of a rotating machine. In this apparatus, a plurality of sensors is positioned adjacent the shaft of the rotating machine for generating sequential pulses with periods proportional to the angular velocity of the shaft. The pulses are generated at intervals such that, during the period between adjacent pulses from one sensor, pulses are generated by each of the other sensors. An oscillator is provided for generating reference pulses at a predetermined pulse repetition rate, and a plurality of counting devices are coupled to respective sensors and to the output of the oscillator for counting the pulses generated by the oscillator. An averaging and reciprocal circuit is coupled to the output terminals of the counting devices for obtaining the average of the counting device outputs and then generating the reciprocal of the average value.