Abstract: A slide valve comprising: a valve body having two axially aligned openings provided with means for connection in a duct; a drive rod; a valve member; and a backing member; wherein the valve member includes a hollow opening out to both faces of the valve member and fitted with a piston movable between a simple abutment at one end and a shoulder in the hollow at an opposite end, the piston bearing against said shoulder via sealing means, a return spring urging said piston towards said simple abutment, said piston including, at its simple abutment end, means for co-operating with a sloping ramp of said drive rod such that during closure of the valve, the piston is thrust against said shoulder of the hollow.

Abstract: An opto-electronic component such as a semiconductor optical amplifier (L) is mounted on a copper base (EL) which is received in a receptacle constituted by two blocks (DA, DB) of ferrous alloy. Two other blocks (BA, BB) carry fibers to be coupled (FA, FB) and they are fixed to said receptacle by weld spots (PA, QA, PB, QB) on the edges of the faces of said blocks that are bearing against one another. The invention is particularly suitable for optical fiber telecommunications networks.

Abstract: A printed circuit board test system includes a test printed circuit board adapted to be connected to a printed circuit board to be tested. At least one of these two boards is equipped with circuits for selecting the types of signal processed by the board to be tested, adapted to place at least one subsystem of the latter either in a test configuration or in a normal configuration. The test board is provided with configuration control ports and equipped with circuits for connecting these ports to the selector circuits.

Abstract: The apparatus comprises a protocol processor circuit connected to a network, a memory having a transmit memory and a receive memory, a transmit control memory and a receive control memory. The memories are connected to the processor circuit via a data bus and to a level 2.2 processor by a bus. The control memories are of the FIFO type, with the transmit control memory being written to by the high level 2.2 processor and being read from by the processor circuit, and with the receive control memory being written to by the processor circuit and read from by the level 2.2 processor. The processor circuit transmits and receives cells containing signalling information, and it performs level 2.1 function of the protocol: detecting transmission errors on a cell-by-cell basis, detecting loss for added cells, splitting up a message delivered by the level 2.2 processor into cells, and de-interlacing cells relating to a plurality of messages on reception.

Abstract: The connection circuit comprises a first differential amplifier circuit having its output connected to a first symmetrical amplifier circuit, a second differential amplifier circuit having its output connected to a second symmetrical amplifier circuit, a power supply and filter circuit for delivering power via a power supply series connection to the two symmetrical amplifier circuits, a balancing circuit, and a loop state signaling circuit. The two differential amplifier circuits are connected firstly to the output of a receive circuit and secondly to ground, and each wire of the line is connected directly via a respective resistor to a transmit circuit. Each symmetrical amplifier circuit is connected to one of the line wires via a contact of a ringing relay and a resistor connected in series. The power supply series connection includes a power supply transistor controlled by a signal indicative of the line being looped.

Abstract: A power supply switchover device is provided for electrical apparatus such as teleaction terminal equipment. A switching circuit puts a storage battery into and out of use by connecting it to at least one supply terminal of the electrical apparatus to which another source is also connected. A control circuit causes the switching circuit to connect the storage battery when the supply terminal falls to a predetermined potential as furnished by the power supply, and a blocking circuit acts on the control circuit to initiate disconnection of the storage battery, when and as long as said terminal is at a potential that is lower than a determined threshold value.

Abstract: The connection system includes at least one connection assembly having at least one connection module with a connection capacity of N optical lines. A connection module comprises first, second, and third optical switch assemblies (C11 to C1n, C21 to C2n, and C31, C32). The first assembly is connected to the N optical lines, the second assembly is connected firstly to the first assembly and secondly to the junctors and the spare junctors associated with the N optical lines, and the third assembly is connected firstly to the first assembly and secondly to at least one test circuit via a line test optical fiber and via a junctor test optical fiber. When using narrowband optical switches, there are two switching assemblies, one for transmission and the other for reception of the signals conveyed by the optical lines, when using wideband optical switches, then a single switching assembly is used both for transmission and for reception, i.e. for both call directions.

Abstract: The interchange system comprises stations connected to a loop link having two rings (A1, A2) making use of a token access method and operating in load sharing mode, with each ring providing all interchanges in the event of the other ring breaking down. Each station has one adapter (1, 2) per ring, a coupler (C), and a terminal (T). Each adapter performs level 1 procedures and lower layer level 2 procedures only. The coupler includes a processor and uses a protocol at the upper layer of level 2 and at level 3 for managing load sharing between the rings, for switching the station onto one ring in the event of the other ring breaking down, and for providing protection against transmisson errors, against messages being duplicated, and against messages being out of sequence, against breakdowns in the adapters and the rings, and against short traffic interruptions due to a station being inserted or withdrawn.

Abstract: The assembly is implemented in the form of an optical head integrating not only an optical isolator (6, 8), but also a semiconductor amplifier and phase modulator (18). The amplifier-modulator is aligned parallel to the light-emitting laser (2) by a rotation compensator (14, 15) that compensates for the rotation applied by the isolator to the polarization of light from the laser. The invention is particularly applicable to optical fiber telecommunications.

Abstract: The stations (S1to SN) are interconnected in series by a ring (A), and the system of the invention includes a spare ring (AS) interconnecting the stations in series, together with two self-healing circuits (CAM, CAV) in each station coupler (CS) between the two connectors (8, 9) of the coupler and its insertion relay (RI). The couplers are interconnected by cords (10; 11) each containing the ring (A), the spare ring (AS), and two detection links (12, 13). Each self-healing circuit includes a relay (6) and a relay control circuit (7) connected to a detection link whose other end is connected to ground in another self-healing circuit. Each relay (6) has fixed contacts (a1, a2, b1, b2), a first moving contact (C1) connected to the insertion relay (RI), and a second moving contact (C2). The second moving contacts (C2) of the two self-healing circuits (CAM, CAV) in the same coupler are interconnected by a spare link (L).

Abstract: The present invention relates to a digital servo-control system whose purpose is to control very high precision equipment. The system includes two digital-to-analog converters, one of which is followed by a divider, with the two converters contributing to producing a control signal. A processor responds to a measurement signal and to a reference value to generate the digital values that are delivered to the converters. The system is particularly suitable for application to servo-controlling a voltage-controlled oscillator.

Abstract: A metal housing for an electrical connector such as a standardized HE12 connector comprises two half-housings enclosing a connector plug adapted to be inserted into a socket. Each half-housing comprises a half-hinge and an orifice having a contour which is open when the two half-housings are open to enable insertion of cables and which is closed when the two half-housings are closed. Fork-shape projections in each half-housing constitute two insulation-displacement contacts for establishing an electrical connection between the half-housing and the screening braid of each cable and to prevent the cable being pulled out. Tangs in each half-housing are inserted in insulation displacement contacts when the two half-housings are closed to constitute electrical screens preventing electromagnetic interference between nearby contacts. A captive screw constitutes both a rotation spindle for the hinge and means for fixing the housing to a nut fixed to the chassis.

Abstract: A device for feeding grease to the bearings of a rotary machine comprising a stator and a rotor, the device comprising injectors for injecting grease into said bearings, the injectors being controlled by an electronic control circuit which has inputs receiving signals from sensors for sensing parameters characteristic of the operating state of the bearings. The injectors are connected to a supply of grease under pressure and comprise injector blocks each connected to a respective bearing feeder channel. The sensors are pressure and temperature sensors, and the electronic circuit includes a clock and generates injection cycles as a function of a preestablished program, taking account of the information provided by the sensors and by the operating time of the bearings.

Abstract: A system for transmitting HDLC frames on a PCM type link uses a single HDLC circuit and a transposition buffer memory to provide a compact system by economizing on the number of components, enabling operation at high speed without risk of starvation on the PCM link. The system uses a single transposition buffer memory with a read cycle distinct from the write cycle cooperating with a single single-channel HDLC frame formatting circuit. The memory is written with the formatted HDLC frames and read under the control of means for selective sampling in the memory of data for building successive blocks of interleaved channels of the PCM frame.

Abstract: The IC card reader includes card positioning and guide means and contact elements which provide electrical connections with conducting areas on the IC card, via which circuits are established with the apparatus in which the IC card reader is incorporated. The card reader includes, in particular, a carriage (8) which is moveable relative to a contact frame (3), having a rest position that it occupies when there is no card in the reader, being urged into its rest position by return means (RA), and an actuated position into which it is thrust by a card (100) inserted in the reader. The carriage (8) is arranged to co-operate with the contact elements (35, 36) in such a manner that when in its rest position, the carriage (8) causes the contact elements (35, 36) to be held in a rest position in which they lie off the insertion path (62) of a card, and when in its actuated position, the carriage (8) causes the contact elements (35, 36) to bear against the contact positions of the card.

Abstract: An anti-return safety apparatus for an installation comprising a vacuum vessel connected to a vacuum pump having an oil seal, wherein the apparatus comprises a valve constituted by a rigid tube having a flexible tube situated therein with the two ends of the flexible tube being fixed in sealed manner to the ends of the rigid tube, a control orifice being provided through the wall of the rigid tube in the vicinity of the middle thereof, the valve being connected between the vessel and the suction inlet to the pump, and in that a slide valve suitable for establishing two different communication paths is provided suitable for establishing a connection between a common outlet C and one or other of two distinct inlets a, and b, the common outlet C being connected to the control orifice of the valve having the flexible tube, the inlet a being connected to the suction inlet of the pump, and the inlet b being opened to atmospheric pressure, the slide valve being electromagnetically controlled by a coil, itself contro

Abstract: A valve comprising a rigid tube in which a flexible tube is situated with the two ends of the flexible tube being connected in sealed manner to the ends of the rigid tube, a control orifice being provided through the wall of the rigid tube in the vicinity of its middle region, and a core also being disposed inside the flexible tube, the core being smaller in cross-section than the inside section of the tube when in the rest state, wherein the core has a calibrated internal passage. The valve is suitable for preventing hammer in an installation having two zones at different pressures P1 and P2.

Abstract: This device is interposed between two lengths of an optical fiber lead-in cable comprising a core constitution by a small diameter stainless steel tube containing a bundle of optical fibers comprises: a metal plug which is brazed to the end of one length of tube and which includes a barrel including a cavity whose diameter is not less than the diameter of the bundle of fibers and whose outside surface has a diameter which is greater than the diameter of the tube, said outside surface being provided with transverse grooves; a block of epoxy resin molded both over a portion of a bundle of fibers and over the barrel; the resin covering portions of the bundle both inside and outside the barrel; a sleeve fixed in sealed manner to the other length of tube; a clamping ring; a viscous hydrophobic liquid injected into the space remaining empty between the sleeve and the block of epoxy resin; and epoxy resin injected into the cavities inside the sleeve.

Abstract: A two stage dry primary pump comprises, in a single common stator: a screw pump at its low pressure end; and a fluid viscous effect, single rotary screw gas exhaust pump at its high pressure end; with a link duct providing communication between the screw pump and the viscous effect, single rotary screw gas exhaust pump. The invention is applicable to vacuum pumps.

Abstract: A pumping assembly for obtaining a high vacuum, the assembly comprising a primary pump (4) and a secondary pump (1) associated in series, the inlet of the secondary pump (1) being taken from an enclosure (3) to be evacuated, the assembly further including means (7) for starting the secondary pump (1) when the pressure upstream from the primary pump (4) drops below a value P.sub.1, the assembly being characterized in that a passive tank (10) followed by an isolating valve (11) are interposed between the outlet (12) from the secondary pump (1) and the inlet (13) to the primary pump (4), and in that it includes control means (7) for closing the isolating valve (11) and stopping the primary pump (4) when the pressure in said passive tank (10) reaches a value P.sub.2 <P.sub.1, and for opening the isolating valve (11) and restarting the primary pump (4) when the pressure in said passive tank ( 10) returns to the pressure P.sub.1.