Abstract: A line switch for a digital telephone switching system utilizes distributed processing. The line switch comprises one or more switch modules. Each switch module is coupled to a central office switching system via one or more PCM lines which utilize common channel signaling. Each switch module comprises groups of line circuits, each line circuit being coupled to a subscriber line. Three separate distributed processor functions are provided in each line switch module. A first processor is utilized to communicate with the central office switching system is provided to control clock generation and rate conversion circuits. Each group of line circuits includes a third processor to control the operations of the line circuits and to gather information from the line circuit.A test bus is routed to the line circuits. The third processor may be utilized to automatically measure and adjust various transmission parameters.

Abstract: A digital to analog converter is employed in the digital line circuit of a telephone system and operates to convert a digital signal indicative of an analog speech signal back into a replica of the analog signal. The converter operates with an interpolated input digital signal to detect by means of a sign bit, the characteristic of an input digital word as being indicative of a positive or negative level. An error correcting signal is provided by the converter which is added to the next digital word to provide a compensated word having a sign bit determined by the remainder and the sign bit of the previous digital word. This word is then processed in sequence to produce an output pulse stream from the sign detector indicative of successive positive or negative values as defined by the input digital words, each of which are modified according to the error correcting signal.

Abstract: A circuit for adapting a telephone subscriber line to operate as a multiparty line is described wherein a plurality of conventional single line subscriber subsets are provided telephone service on the subscriber line such that each subscriber has privacy at all stages of call progress. In accordance with another feature of the present invention, frequency selective ringing is not required to prevent ringing from occuring at other subscriber subsets on the multiparty line when a party is called. The circuit of the present invention controls the switching of battery polarity at the central office to connect and disconnect subscribers from the line. The invention further provides automatic telephone number identification when calls are initiated by varying a unique identity tone for billing purposes. The invention also uniquely provides for user transparent reverting calling such that no special dialing procedure is required to make reverting calls and complete privacy is maintained, even on reverting calls.

Abstract: The zoom focus and deflection assembly for an image-to-electron beam converting electron discharge device comprises a magnetic deflection yoke and a magnetic electron beam focusing coil having N sections each having its own adjustable current source such that at least the opposite end ones of the N sections have the magnitude of current therethrough changed simultaneously in the opposite direction, where N is an integer greater than one.

Abstract: A line switch for a digital telephone switching system utilizes distributed processing. The line switch comprises one or more switch modules. Each switch module is coupled to a central office switching system via one or more PCM lines which utilize common channel signaling. Each switch module comprises groups of line circuits, each line circuit being coupled to a subscriber line. Three separate distributed processor functions are provided in each line switch module. A first processor is utilized to communicate with the central office switching system and to coordinate the operations within the line switch module. A second processor is provided to control clock generation and rate conversion circuits. Each group of line circuits includes a third processor to control the operations of the line circuits and to gather information from the line circuit. A busing arrangement is provided within the line switch such that both control information and PCM voice data are routed throughout the line switch.

Abstract: A multichannel duplex radio system for cordless telephone in which digital information is sent between the two ends. The data is divided into blocks which are transmitted in a fraction of the original block length. The other time slots are used for the duplex return path and for other similar equipment operating nearby. A direct conversion radio receiver is used in which the local oscillator signal is modulated for transmission.

Abstract: A method of fabricating a very small-size gate on a semiconductor substrate includes covering the substrate with a photoresist layer, masking an area of the photoresist layer that has a size exceeding the desired size of the gate, subjecting the photoresist layer to overexposure so that the size of the unaffected area is reduced to the desired size, removing the overexposed region of the photoresist layer, providing a protective coating on such region, clearing the unaffected photoresist material out of the area occupied thereby, and depositing gate material at least in the thus obtained recess. The gate material may be deposited over the protective coating, in which case the zone at which the gate is to remain is protected by unexposed photoresist material and the remainder of the gate material is removed from the protective coating.

Abstract: A radio receiver for FM signals having a demodulation system to produce an approximation to an analog output by either measuring the time intervals between successive zero crossings in the I.F. (FIG. 1, FIG. 2B) or by filtering pulses produced at each zero crossing of the I.F. (FIG. 1, FIG. 2A). The demodulator includes two signal pathways in quadrature phase relation, the second signal either lagging or leading the first signal in dependence on whether the received signal frequency is above or below a local oscillator frequency. The modulation frequency can carry analog information separate and apart from the on-off (digital) information.

Abstract: The invention concerns a seal device comprising a rotating and a non rotating seal ring, a so-called mechanical seal.The rotating (2) and non rotating (3) rings are pressed towards each other by an elastic socket (4) surrounding the shaft (1).

Abstract: The microwave resonator includes an enclosed resonator housing and a hollow central conductor having one end fastened to a bottom of the resonator housing and extending toward a top wall of the resonator housing. The other end of the central conductors is spaced from the top wall and includes an adjustable bellows assembly disposed coaxial of a longitudinal axis of the central conductor. A non-rotating, axially movable drive shaft is disposed coaxial of the axis of the central conductor within the central conductor. One end of the drive shaft is fastened to the bellows assembly and the other end of the drive shaft is coupled to a drive means disposed in the bottom wall to cause axial movement of the drive shaft to adjust the axial length of the bellows assembly and, hence, the axial length of the central conductor to adjust the resonant frequency of the microwave resonator.

Abstract: A mechanical seal device includes a seal ring arranged non-rotatably in a cup which is locked against a shoulder on a shaft. The cup contains a ring of a flexible material which axially supports the seal ring. The flexible material ring is provided with a collar situated between the seal ring and the shaft, thus sealing the space and centering the seal ring on the shaft.

Abstract: An optical fiber which has just been drawn from an optical preform is provided with an external hermetic coating by using a heterogeneous nucleation thermochemical deposition technique. This technique involves passing the fiber through a reaction zone which contains a gaseous medium that includes a reactant which decomposes, or a mixture of reactants which chemically react, at a predetermined temperature to form the material of the coating. Only the fiber but not the gaseous medium surrounding the same is heated to the predetermined temperature, especially by directing radiation onto the exposed circumferential surface of the fiber, so that the decomposition or the chemical reaction takes place directly on the exposed surface of the fiber rather than in the gaseous medium, accompanied by simultaneous deposition of the coating material on the exposed surface of the fiber. The resulting fiber with hermetic coating can then be provided with an additional polymer coating layer.

Abstract: A line switch for a digital telephone switching system utilizes distributed processing. The line switch comprises one or more switch modules. Each switch module is coupled to a central office switching system via one or more PCM lines which utilize common channel signaling. Each switch module comprises groups of line circuits, each line circuit being coupled to a subscriber line. Three separate distributed processor functions are provided in each line switch module. First one processor is utilized to communicate with the central office switching system and to coordinate the operations within the line switch module. A second processor is provided to control clock generation and rate conversion circuits. Each group of line circuits includes a third processor to control the operations of the line circuits and to gather information from the line circuit.The second processor is used to select which of a plurality of sources may be used to provide clock signals within the line switch module.

Abstract: This invention relates to continuous manufacturing of insulated wire and conductor, and in particular to heating cables having "cold ends". A process is described by which predetermined lengths of resistance conductor (4) and of cold end conductor (9) are continuously and alternatively jointed together. After insulation and provision of additional protective sheats the continuous composite conductor is cut into cold end heating cables. A conductor jointing process is described.

Abstract: A tray loading apparatus includes an inclined support having a displaceable front part so that the front wall of a tray can be brought into abutment with the front end of a stack carried by the support and to be loaded in the tray after a backing plate supporting the stack front end has been removed. The stacking apparatus includes a conveyor able to apply the front portion of each envelope conveyed in a direction making an angle with the above backing plate against this backing plate and a belt arrangement operating on the front portion of each envelope to cant the rear part of the envelope into engagement with a deflector after the front portion has been applied against the backing plate.

Abstract: A rod of silica 14 is inserted into a substrate tube 10 whose bore is lined with a layer 11 of material having a refractive index less than that of silica. This layer 11 is itself covered with a layer 12 of silica. The assembly of the rod and tube is drawn into fibre, or its components are fused together to form a solid cross-section optical fibre preform.

Abstract: A photodetector in the form of a JFET in which the gate is defined in a rib 5 which is also designed to function as an optically absorbing optical waveguide into which the optical input signal is launched.

Abstract: A method of manufacturing thin film dielectric material by directing vapors of reactants containing lead and additional metals and an oxidizing gas onto a heated substrate to form a layer of dielectric material thereon, which layer can be of a high dielectric constant (greater than 5000).

Abstract: A line switch for a digital telephone switching system utilizes distributed processing. The line switch comprises one or more switch modules. Each switch module is coupled to a central office switching system via one or more PCM lines which utilize common channel signaling. Each switch module comprises groups of line circuits, each line circuit being coupled to a subscriber line. Three separate distributed processor functions are provided in each line switch module. A first processor is utilized to communicate with the central office switching system and to coordinate the operations within the line switch module. A second processor is provided to control clock generation and rate conversion circuits. Each group of line circuits includes a third processor to control the operations of the line circuits and to gather information from the line circuit.The second processor is used to select which of a plurality of sources may be used to provide clock signals within the line switch module.

Abstract: A device for coating optical fibers with at least two coatings. The device comprises a holding block and at least three coating dies. The holding block has an outer surface with first and second ends, and an inner surface defining a channel extending from the first end to the second end. The coating dies are press fit into the channel, separated by resin chambers. The holding block is further provided with passages providing fluid communication between the resin chambers and the outer surfaces of the holding block.