Abstract: The present invention relates to an improved transcoding apparatus (1) for use in a switching network of a telecommunication system, said transcoding apparatus (1) including a) a plurality of transcoding units for source encoding and decoding data, for example speech data, wherein at least one transcoding unit (11) of said plurality is capable of operating in tandem-free operation mode, b) switching means (12) adapted to switch data through said plurality of transcoding units, c) a transcoder controller (13) for controlling said switching means (12) and said plurality of trnascoding units, wherein said transcoder controller (13) is adapted to d) instruct said switching means (12) to insert one of said at least one transcoding unit (11) into a data path associated with a connection between a mobile terminal of said telecommunicaiton system and said switching network, and wherein said transcoder controller (13) is adapted to e) instruct said one of said at least one transcoding unit (11) to operate in tandem-fr

Abstract: A digital transmission system, such as a mobile radio system, having a transmitter for transmitting codewords which are derived from a digital signal, and a receiver for receiving codewords, the receiver including a decoder with a prediction filter which is excited by an input signal to produce an estimated digital signal. To improve reconstruction of the digital signal in the event of disturbances, the decoder includes a first switching circuit for switching off the input signal of the prediction filter when a disturbed codeword is received, and a second switching circuit for switching substitute values formed from previous values of the estimated digital signal instead of the estimated digital signal when the input signal is switched off.

Abstract: An adaptive prediction filter which provides recursive calculation of prediction coefficients from sampled values of segments of a sampled audio signal. In order to obtain improved computation accuracy the coefficients are in block floating point format, and are recursively calculated from reflection coefficients. Upon calculation of a kth reflection coefficient the k-1 previously computed prediction coefficients are recomputed again based thereon. In the event that results in an overflow of the number of bits in the mantissa of a prediction coefficient which is being calculated, the block floating point format is adapted by increasing the common exponent of the block. That conventionally required recalculation of all previously recalculated coefficients.

Abstract: A coder/decoder for samples of speech or other audio signals with bit rate reduction includes an adaptive prediction filter having filter coefficients which are recursively computed according to the known Levinson-Durbin Recursion. Such computation is based on reflection coefficients derived from correlation coefficients applicable to segments of the audio signal samples, the reflection and prediction coefficients being in N-bit fixed point arithmetic. A k.sup.th reflection coefficient after its first computation is buffered with a minimum accuracy of N+1 bits, and the k-1 previously computed prediction coefficients are recomputed with a limitation of N bits. If overflow occurs, the buffered value is divided, e.g. by 2, after the re-computation is completed and then rounded to N bits. Since rounding occurs only after the new prediction coefficients are derived, the recursion achieves reduced error and is simpler to calculate.

Abstract: A telephone switching system, or teleconferencing arrangement, in which each participant hears all the other speakers but does not hear his own voice. The speech intensity of each participant is measured and subtracted from a signal which is based on the sum of all the other participants then speaking. This difference signal is then compared with a threshold to determine if this participant is rated "speaking" (signal to be added for others to hear) or "listening". The speech intensity signal is multiplied by a weighing factor based on this comparison, before adding to the other weighted signals to form the sum signal.

Abstract: Devices for the digital recording and reproduction of speech signals are used, for example in answering apparatus. In order to reduce the quantity of data to be stored without noticeably affecting the acoustic quality of the speech, it is proposed to encode speech signals by means of a residual signal speech encoder.

Abstract: A method and an apparatus for conveying and synchronizing the movement of articles. Two conveyor belts are thereby provided. A synchronizing device is arranged between the conveyor belts. The phase relationship of the individual articles and the speed of a receiving belt can be adjusted with the help of the synchronizing device. To facilitate the adjusting of the position of the articles and to make such adjusting more precise, the invention provides that the first and the second conveyor belt are moved at a faster speed than the receiving belt.

Abstract: During algebraic summing of code words from conference participants to form a partial sum-code word overflow of the values may occur. Such an overflow can be prevented when prior to the adding operations the numerical range is extended and an adjustment of weighting factors is effected in dependence on the measured speech intensity of the partial sum-code word. By multiplying by these (attenuation) factors the outgoing subscriber-code word is mapped again on the original numerical range in the attenuation circuit. To reduce a noise level originating, for example, from line interferences, quantization errors, etc. subscribers which are currently not speaking can be attenuated in a further attenuation control circuit of the conference arrangement.

Abstract: To design a compressor system with a screw-type compressor, the housing of which has cavities for air guidance and oil separation, in an economical way for small delivery quantities, there is a disc-shaped housing with a longitudinal dimension corresponding essentially to the rotor length, and in this housing the compressed air flowing out of the compressor and mixed with oil is deflected in a radial and a peripheral direction for oil separation. The oil separator, the oil filter and the air filter are attached as separate units to the end face of this housing. The bearing plate of the drive motor is designed as a mechanical transmission space.

Abstract: A ring-shaped air cooler has an inlet at the top and an outlet at the bottom. A peripheral wall surrounds the outlet and projects upwardly forming a condensate trap. Air admitted at the inlet flows in two streams through each half of the ring. The streams impinge on and are deflected by surfaces of the wall, removing condensate therefrom.

Abstract: A screw compressor with liquid injection wherein the units previously disposed separately from one another, such as the air filter, liquid separator, and so on, are integrated into a single housing. Various compartments are formed in the housing by means of partitions, such that the compartments provide for good separation of entrained liquid from the compressed air being achieved because of large flow cross-section, maximum utilization of the available flowpath and multiple deflection of the current of compressed air. The compact construction results in a substantially smaller overall compressor size than that of comparable known compressor plants, in a reduction of manufacturing cost and simplification of the assembly of a compressor plant.

Abstract: A suction regulator for a compressor, in particular a screw compressor with oil injection, having an element which opens and closes the suction inlet to the compressor. The element closes the inlet due to the bias of a spring, opens the inlet against the bias of the spring in response to compressor discharge pressure and is positioned to regulate the suction in response to the system line pressure.

Abstract: A lock with a stator and a rotor having a key slot or channel for receiving a flat key has four tumbler rows with pin tumblers, the rows extending in the axial direction of the rotor. The planes containing two of the tumbler rows are inclined by identical angles on opposite sides of the median longitudinal plane of the key and intersect a narrow edge surface of the key adjacent the corners so that the recesses in the key to receive the pin tumblers open on both the narrow side and the flat side key, making it possible to reduce the constructional size of cylinder lock.

Abstract: A fluid pump unit having a pump, a driving motor which may be air-cooled and various system components which require a cooling air stream includes a fan which is located between the motor and the pump approximately at the midpoint of the cooling air flow route. The air flow route is arranged to be as long as possible and is provided with sharp angular bends and sound-deadening barriers to limit noise transmission to the exterior of the housing. Air-cooled system elements are located between the fan and housing exterior to act as noise deadeners and further reduce noise transmission.

Abstract: A method in which automatic selection of the mode of operation for a compressor unit is achieved and is dependent on the conditions under which the compressor unit is operated. Depending on the existing compressed air demand and the time sequence thereof, the compressor unit operates in a continuous mode, an intermittent mode, or a regulated mode. During continuous mode operation, the compressor intake is either opened or closed so that the compressor unit operates respectively under zero load, when a minimum pressure condition exists, or full load, when a maximum pressure condition exists. During intermittent mode operation, the compressor unit is turned off when a maximum pressure condition exists and is turned on when a minimum pressure condition exists. During regulated mode operation, the compressor intake is varied between open and closed positions depending on output pressure.

Abstract: A rotary piston machine has a cylindrical housing with inlet and outlet ports. A rotor mounted in the housing has an elongated diametric recess. A circular piston eccentrically mounted in the recess effectively reciprocates therein as the rotors turn.

Abstract: A rotary gas compressor or expansion motor with a housing having circumferentially spaced inlet and outlet ports. An outer cage or sleeve rotor has alternate slots and teeth. An inner lobe rotor has lobes which mesh with the slots of the cage rotor as the two rotate. The space between the two rotors is filled with a crescent-shaped housing member. The slots, teeth and lobes of the rotors are helical.

Abstract: A compressor intake throttle valve is positioned in accordance with the inlet suction of the compressor, regulating the volume of inlet air in accordance with the load on the compressor. A relief valve connected with the compressor outlet opens when the compressor outlet pressure exceeds a set value and vents compressed air to the compressor intake passage at a point between the throttle valve and the compressor inlet, closing the throttle valve.

Abstract: A multiple function valve for a compressor cooling liquid system. A cylindrical valve housing has an inlet at one end and an outlet at the other with a flow passage therethrough. A thermal valve controls the liquid flow between the inlet and outlet and diverts liquid to a heat exchanger connected with ports in the valve body. A pressure responsive on-off valve is located between the thermal valve and the outlet. A filter is connected between the inlet and the thermal valve.