Abstract: A cock for low-pressure bleeding of a gas from a gaseous mixture, said cock having a body (1) with an inlet (12) and a pumping outlet (13) for the mixture and a bleed outlet orifice (15), and a valve (2) which co-operates with the valve body and is situated between said orifice and the inlet, wherein the valve includes a semi-permeable membrane with a first surface (6A) which communicates with said inlet and a second surface (6) which communicates with said bleed orifice, the valve assuming a first position in which it allows the mixture to pass directly from the inlet towards the bleed orifice when the pressure of the mixture is lower than a given pressure, and a second position in which it closes the bleed orifice when the pressure of the mixture is higher than said given pressure, the gas to be bled off then passing through said permeable membrane.

Abstract: Subscribers (Ab1 to Ab8) in a telecommunications system are normally connected via respective subscriber lines (L1 to L8) to respective subscriber terminals (T1 to T8). Automatic subscriber line test means are connected via a subscriber line test bus (BL) and various relay contacts (r1 to r8 and re1 to re8) to the subscriber lines for testing purposes. Eight subscriber terminals (T1 to T8) populate a single circuit card, thereby constituting a terminal unit (TU1 to TUp). A group of terminal units is associated with a spare terminal unit (TUS). When a faulty terminal unit is detected, it is taken out of service and the spare terminal unit takes over. This is done by switching the subscriber lines connected to the faulty terminal unit over to the test bus. The spare terminal unit is likewise connected to the test bus. To enable the test means to continue testing the remainder of the telecommunications system without being interrupted by the emergency connection via the test bus, isolator means (I) are provided.

Abstract: Apparatus having application to surgical operations has an ultra-violet laser pulse generator (1), an infrared laser pulse generator (3), an optical fibre (11) which transmits these pulses in one direction to the organ (13) and returns the fluorescence emitted by the organ together with reflected infrared radiation. Said returned radiation is detected by two receivers (25 and 20) and a circuit (31) for processing the electric signals delivered by said receivers.

Abstract: A duplicating stencil is produced by placing an electrostatically-produced image on a substrate in contact with an ink-impervious surface layer of a stencil blank, bending the image to the surface layer by the application of heat and/or pressure and stripping the substrate from the stencil blank to remove the surface layer in the image area. The surface layer may comprise a synthetic resin composition containing a finely dispersed pigment and is attached to the porous base tissue of the stencil blank by an adhesive. Bonding of the image to the surface layer and possibly also fixing of the image to the substrate in the same operation can be effected by means of infra-red heating.

Abstract: Crimping tongs in particular for crimping a sleeve on a cable, said tongs having jaws coupled to each other so that one moves relatively to the other, a cam (15) driven by a ratchet wheel (16) which actuates a toggle joint device (20,21,22) a catch being installed on the moving handle (13) so as to drive the ratchet wheel step by step by moving the moving handle, the toggle joint device making the moving jaw (12) rotate in the closing direction. With a view to axial crimping, the moving jaw (12) has a moving die (14) which moves rectilinearly. A spring (25) biases the toggle joint to move the one jaw toward the other, and a trigger (19) is pressed to open the jaws sufficiently for insertion of a sleeve to be crimped. Releasing the trigger causes the jaws to hold the sleeve under the action of spring (25); so that the crimping action can be performed with one hand.

Abstract: The method relates to the detection of the training sequence of a self-adapting equalizer at the receiver end of a synchronous data-transmission system, the training sequence being preceded a synchronizing transmission of data transformed on coding into a succession of multivalent symbols such that the transmitted signal has a frequency spectrum which is substantially a single large-amplitude spectrum line. The training sequence begins with the transmission of data transformed on coding and at least one null symbol. The method consists in detecting the presence of the large-amplitude spectrum line in the signal formed by the received but not yet equalized symbols by means of a digital filter 40 and in thereafter detecting the first following major drop in absolute amplitude of the signal that lasts throughout the duration of one symbol period. This is done by means of a low amplitude level detector 50.

Abstract: An addressing circuit has a register search counter (20) connected to a first multiplexer (24) and to a second multiplexer (25), a memory (33) connected to the output of the first multiplexer for writing the type of processing of each register, a register counter (26) connected to the second multiplexer which is itself connected by its output to three address registers (28, 30, 32) in series. The output of the second register (30) is connected to the first multiplexer to write address the memory under the control of a write signal (CRW). The register search counter read addresses the memory and stops as soon as a register requiring rapid processing is detected; the second multiplexer receives a transfer signal (ST) to transmit the address applied to the output of the register search counter; the register counter (26) stops during the transfer signal.

Abstract: A multiple stylus print head, e.g. for printing a document in a facsimile system, has at least two parallel lines of styluses with the styluses being offset from one line to the next. Each line of styluses is built up from several tiers of interdigitated conductor pins (C) having tips that constitute the styluses per se. The tiers of pins are held together by respective strips of insulating material (7) forming comb-like structures which are then stacked together in such a manner that the combs fan out from the line of styluses. A plurality of groups (G.sub.1, G.sub.2) of stylus line forming comb structures are stacked together into a single stack.

Abstract: In a method of detecting the presence of speech in a telephone signal, a signal sequence is interpreted as constituting speech if its mean power level exceeds a threshold, the value of which is decreased as the number of passages through zero level in the sequence approaches 1.25 per millisecond (0.25 Hz). A speech detector implementing this method receives pulse code modulated signal samples on its input. It comprises a squaring circuit driving a digital accumulator whose output signal is proportional to the mean power level of each of consecutive 4 millisecond signal sequences. A change of sign detector and a second digital accumulator indicate the number of passages through zero level in each of these sequences. Banks of threshold comparators and a selector circuit are used to choose between the various threshold values. The selected value is lowest when the number of passages through zero level is between 5 and 6 per millisecond.

Abstract: The power supply system comprises three levels: a primary level (PRI), a secondary level (SEC), and a tertiary level (TER). The secondary level is constituted by power supply circuits (S1 to Sn) which provide galvanic isolation between the primary and the tertiary levels, and which provide at least one intermediate voltage at a fixed level relative to a system reference potential (point R). The tertiary level comprises chopper power supplies (RD), converters (CV), and inverters (OND) connected to user equipment (UT).

Abstract: An apparatus for chemically activated depositing in a plasma. Said apparatus includes a chamber (1) in which a vacuum is maintained, said chamber being closed by means of a top plate (2) and a bottom plate (3) which are removable. Said apparatus further includes a substrate support (5) disposed about said axis, a reactive gas distributor manifold and means (4) for setting up a plasma inside said chamber (1). Said manifold (8) has two circular end portions (9,10) interconnected by pipes (11) in which gas outlet orifices are provided; said pipes being rotatable at a uniform speed about the axis of the chamber inside said substrate support; said support being of polygonal cross-section and constituted by rectangular longitudinally extending facets on which the substrates (7) are deposited.The invention is used to deposit chromium, silicon, aluminium and the like.

Abstract: The present invention relates to 1+1 type carrier telephone transmission systems for connecting two subscriber terminals to a telephone exchange via a common two-wire link, one of the terminals being connected via the conventional audio channel, and the other terminal being connected by a channel referred to as a super-audio channel. Disturbances caused in the super-audio channel by signalling, dialling and calling signals of the audio channel are reduced by inserting a current-limiting two-port network in series in the audio channel and at the exchange end of the 1+1 system, in between the filter which separates out the audio channel and the rest of the exchange. Advantageously, an interference limiting low-pass filter (50) is also placed in series on the audio circuit. It has a capacitive shunt arm with a mid point connected to exchange battery ground.

Abstract: The pump comprises a pump stator (5), an electric motor stator (4), and a rotor (6) that constitutes the rotor both of the pump and of the electric motor. The pump stator comprises a tubular non-magnetic lining to the electric motor stator, and the rotor is mounted excentrically inside said tubular lining and is equipped with radially movable vanes (63) that co-operate with said lining to provide pumping action when the rotor rotates. The arrangement is particularly applicable to oil-sealed vacuum pumps, and has the advantage of being more compact than units of similar performance, but equipped with a pump and a motor that are separate and interconnected by a mechanical coupling, as is conventional practice.

Abstract: The object requires a would-be user to supply an authorization code within a predetermined number of attempts, otherwise the object is invalidated. The object has at least one memory (1) in which the results of attempts at use are stored in permanent binary form. The object also includes memory write means (3) and discriminator means (9). These are arranged to distinguish between an un-interrupted sequence of said predetermined number of failed attempts (in which case the object is invalidated) and a sequence of failed attempts which is interrupted by at least one successful attempt.

Abstract: A method and apparatus for accentuating the features of a monochrome image reproduced by means of a digital transcription.The apparatus includes an analog portion disposed between the digital-to-analog converter DAC (5) and an analog-to-digital converter (15) with analog sampling units (6,7), comparators (10,11,12), a subtractor (9) an amplifier (13) and a limiter to select and calculate the corrective term depending on the difference and on the digital processing means (17,18,19 and 20) to add the corrective terms to the numbers of the digital transcription.

Abstract: A test system for a stored program controlled time-division switching network subdivided into subsystems. The test system includes circuits for selecting, injecting and retrieving data samples and testing for the correct setting of switchpaths through the switching network. A stored program control unit receives test instructions and transmits in response thereto reporting messages including retrieved data samples. A selection control circuit interconnects the subsystems to which a test instruction relates. The subsystems are provided with an interchange circuit for receiving and storing samples, a sample injection and retrieval circuit, and a circuit for synchronizing the receiving and storing circuit with time slot information identifying a sample which has been received and the sending circuit with the time slot into which a sample is injected.

Abstract: Image printing stylus bar, manufacturing method therefor and image printing device.The present invention relates to an image printing stylus bar with as many styli as there are image points on a scanned line on a document to be reproduced, a manufacturing method therefor and a printing device constituting an application thereof.The stylus comprises 2.m register stage chips (59, 60) each having a serial data input, n parallel outputs, a serial data output and control inputs, disposed on at least one film (57, 58) and connected in series in groups of m to constitute two shift registers, the parallel output of each of the m consecutive chips being connected to respective styli (51, 52) for marking image points with the same parity on each line.

Abstract: An apparatus for constituting a rotary magnetic brush comprises a hollow cylindrical member (11) with permanent magnetic strips arranged axially along its periphery. The strips have outwardly directed magnetic poles in a configuration in which north poles and south poles alternate circumferentially. A tube (13) made of non-magnetic substance surrounds said member without touching it. The tube is intended to have particles of magnetic powder deposited on its surface and the particles are made to rotate by rotating the member (4). This causes a rotating layer or "brush" of magnetic particles to be formed on said tube. Said member (11) and the tube (13) which surrounds it are longer than the "brush": An end portion projects beyond the "brush" and is housed in an electrical stator (14) which drives the member (11) by making use of the poles which form the brush. The invention applies to developing electrostatic latent images.

Abstract: A digital frequency sender comprises a generator which supplies multi-frequency codes by cyclically scanning a table under the control of a time base (BT). The sender comprises a logarithmic generator (GL) which delivers single-frequency signals, a logarithmic adder (AL) which sums two single-frequency signals in compressed form, and a frequency output unit (DF) controlled by a computer (CAL). The invention is particularly applicable to time division telecommunication exchange division.

Abstract: An alarm preprocessing logic system for use in a computer controlled digital switching exchange including a central computer, the alarm preprocessing logic system comprising defence modules each allotted to a respective portion of the exchange for detecting a plurality of types of alarm therein and including means for forwarding detected alarms via redundant alarm data transmission means (CAa, CAb, SLM1, SLM2, COL) to alarm processing logic including: means for confirming an alarm (PT2); means for attributing a category to received alarms depending on type of alarm and on the exchange unit which originated the alarm; and means for grouping alarms according to the category attributed thereto (PT1, MDI, MAP), and for classifying alarms in an order of priority; the alarm processing system further comprising data interchange logic connecting the alarm processing logic to the exchange central computer and arranged to ensure that alarms are sent to the central computer in their order of priority.