Abstract: The selector device for a character-carrying element of a printing machine comprises a d.c. electric motor whose rotor is capable of selectively rotating in both rotational directions a coupling arrangement comprising a pinion on the motor shaft and a gear on the shaft which carries the hub for mounting a daisywheel printing element and a strobe disc which provides the position signals used to control character selection. A device for taking up clearances minimizes the radial clearances between the pinion and the gear. Thus the motor is mounted on trunnions and urged by a spring to tilt in the sense urging the pinion into the gear.

Abstract: A re-inking device is fitted to a cartridge for an inked ribbon. The cartridge comprises a magazine housing the ribbon which is of the closed loop type and which is disposed in randomly distributed loops, and a pair of rollers for the unidirectional feed movement of the ribbon. The re-inking device comprises an ink reservoir or inker, an ink metering wick and a spring. The pair of rollers comprises two toothed wheels and the inker is disposed in a housing adjacent to the wheels. The ink metering wick comprises a bundle of capillary fibres and is disposed between the inker and the wheel. The spring presses on the metering wick to hold the fibres at one end in constant contact with the outside surface of the wheel. The crests of the teeth of the wheels are of a rounded section and the inker is of a parallelepipedic shape, is of polyester fibres with external co-extrusion and contains an amount of ink such as to occupy only half the volume of the inker.

Abstract: The system comprises a series of input-output units (I/O) connected by means of a bus (21) to a central unit (CPU) capable of accepting at least one category of vectored interrupts requested by the I/O units and a category of non-vectored interrupts.The vectored interrupts are divided into at least two levels in which relative priority between units belonging to the same level depends on the position of the respective connection to a conductor of the bus.Performance of an interrupt is carried out by means of a routine which includes a closing tail. The performance of a series of interrupts of the same level may be carried out serially by suppressing the tail of all the routines except the last.The non-vectored interrupts are divided into a plurality of levels which are defined by the content of a register which is capable of being variably loaded by means of a suitable instruction. The content of the register in turn addresses a specific routine for performance of the interrupt.

Abstract: In an ink jet printing element in which the drop is expelled by generating a current pulse through the ink in the nozzle, in order to reduce the control voltage, a first pulse (Tr) for heating the ink is generated, followed by a vaporization pulse (Tv) with a delay such as to make the printing position independent of the direction of movement of the element with respect to the paper. The heating pulse (Tr) is generated by a circuit (31) controlled by a temperature sensor (34) so that the duration of the heating pulse has a negative temperature coefficient. The vaporization pulse (Tv) is generated by a circuit (32) manually controlled (potentiometer 39) to determine the pulse duration on the basis of the desired strength of the printing. The delay between the two pulses is controlled by a delay circuit (38), e.g. a monostable circuit. The two pulses are applied to a transformer (35) which generates the voltage between the electrodes.

Abstract: A control circuit (17) applies a voltage pulse to a piezoelectric transducer (16) to create pressure in a chamber (10) open to an ink reservoir (14) at one end and closed by an ink nozzle (13) at the other. The control circuit (17) generates a pulse formed by one or two waves, each comprising a secondary portion delayed relative to the primary portion by a time which is double the reflection time that is characteristic of the chamber (10), thereby cancelling reflection of the drop expulsion pressure. The form of the wave is determined by a series of variable resistors disposed in the circuit while the time is regulated by an element for regulating the period of oscillation of the circuit. Alternatively the form of the wave is recorded in digital form in an ROM addressed by a counter while the period of oscillation is regulated by acting on a timer for controlling the counter.

Abstract: The cartridge for an inked ribbon comprises a casing having a magazine for housing the ribbon of the closed loop type and disposed in randomly distributed turns, and a pair of rollers for the feed movement of the ribbon. A re-inking pad is rotatable in the casing and an ink distribution roller co-operates with the pad for re-inking the ribbon. The distribution roller comprises a shaft having its ends projecting from the ends of the roller and housed for rotary and sliding movement in slots in the casing and the cover. The slots are rectilinear and have their axes co-planar with the shaft of the pad to permit movement of the roller away from and towards the pad. The distribution roller is held in contact against the pad by the tension applied to the ribbon by the rollers. The tension of the ribbon automatically regulates the contact pressure of the distribution roller against the re-inking pad and optimizes re-inking of the ribbon.

Abstract: The apparatus comprises a dot matrix character generator (16) which includes a ROM (17) for a series of standard alphanumeric characters, for the ISO alphabets, the Kana alphabet and a series of Kanji ideograms which are more frequently used. The character generator further comprises a RAM (18) in which other Kanji idoegrams can be selectively stored. They are normally registered in an archive mass memory (47) and can be sequentially transferred to the RAM, a portion of which operates as a FIFO memory if the code required is not present therein. The character generator (16) is connected by means of an internal bus (42) to at least a video control unit (19) and a control unit (27) for a dot printer (38), which units may be served in accordance with a bus priority and arbitration logic. The printer is provided with a printer control unit (93, 82, 83, 41) having an auxiliary character generator (41) for the ISO and Kana characters and a reduced group of Kanji characters.

Abstract: The inclination adjusting arrangement is applied to a keyboard having a base structure in which a plurality of keys is mounted. The keyboard is provided in its lower portion with fixed front support feet and rear support feet. The rear feet can project by varying amounts from the bottom of the base structure in such a way that the angle of inclination of the plane of the keys is variable with respect to the desk top. For the purposes of adjusting the degree of projection, the rear feet are pivoted and movable along their own axis by means of a slot which co-operates with a fixed pivot pin on the base structure. Each rear foot comprises a positioning tooth which is disposed opposite a support surface and which is capable of selectively engaging with a seat of a series of seats of the base structure. Resilient means which co-operate with the pin hold the positioning tooth engaged with one of the seats.

Abstract: An interface circuit for transmitting and receiving binary data as between a plurality of transmitting/receiving units such as for example electronic typewritters which are connected together. The circuit is suitable for transmitting and receiving data and timing (clock) pulses on two different lines, at a frequency particular to the transmitting unit. The circuit is provided with a binary counter prior to the transmission of data, the clock line is sampled to establish if the line is free and thus ready to receive, or occupied.

Abstract: The operator station comprises a series of manual controls on a keyboard for handling calls, some of which are provided with a visual LED indicator, and an alpha-numeric display (53) for the items of information necessary to the operator for handling calls. The operator station further comprises a voice synthesizer (100) for messages corresponding to the above-mentioned items of information, which is activated by the controls of the operator station to permit a blind operator to operate the exchange. The keyboard comprises two additional keys for respectively controlling the emission of a message relating to the status of the exchange and repetition of the message relating to the last key actuated by the operator. The operator station further comprises two manual adjusting members (108 and 106) respectively for the speed of the synthesizer and for the volume of the voice message.

Abstract: The device comprises a flange (14) which is fixed to the shaft (12) of the motor and which is provided on its front face with a plurality of radial teeth (28) spaced by recesses each having their active side surfaces parallel to each other and to the radial line through the recess. Removably connected to the character-carrying disc (11) coaxially therewith is another disc (35) of smaller diameter which is provided on its outward front surface with radial teeth (48) having their active side surfaces (50) parallel to each other and capable of being coupled to the radial recesses of the flange which is fixed to the motor shaft. On the other front surface, hooks (38, 39) engage in holes (21, 23) in the disc. In an alternative embodiment the teeth (48) are integral with the hub (16) of the disc (11) itself.

Abstract: The control apparatus, in particular for electronic typewriters, comprises a lower guide for guiding a sheet of paper beneath a platen roller and up to a printing line of the platen roller, and a series of paper pressure rollers for guiding the sheet beyond the printing line. The pressure rollers are carried by a frame which is movable manually by a lever, a spring and lever and a pin and slot coupling to move the pressure rollers away from the platen roller and to activate a switch to initiate motor drive of the platen roller. The frame further couples a cyclic actuating mechanism to a drive pinion element of the platen roller. When the plate rotates, this mechanism acts on the frame so as to effect automatic closure of the pressure rollers, such as to permit engagement of the pressure rollers with the upper edge of the paper and subsequent printing in a region of the sheet adjacent to its top edge.

Abstract: The device comprises an electric motor whose rotor is capable of rotating selectively in either direction and a transmission unit which comprises a sleeve carrying a gear at an input end in mesh with a pinion on the motor shaft. At the output end of the sleeve a toothed pulley is engaged with a tensioned, toothed belt for moving the print unit back and forth. The sleeve is journalled on a shaft which can shift laterally at the input end and is urged by a spring and lever to shift in the sense forcing the gear into mesh with the pinion, thereby to minimize the radial clearance between the pinion and the gear.

Abstract: An obturator disc comprising a cylindrical element (11) of transparent plastic material provided with a unitary hub (13) by means of which it can be connected to a rotating member. To a front surface (14) of the cylindrical element there is applied, by a photographic process, a layer of opaque material in an annular zone of which there is formed a plurality of transparent windows (16) of high definition.

Abstract: Text is displayed on a VDU (23) using a character generator (26) and a generator (27) for attributes such as underline, enhanced brightness and so on. The codes for the generators are stored in a page store (29). Two auxiliary memories (35 and 36) are used to store address pointers. These memories are used in alternate raster scans to control the display, the unused memory being updated for the next raster scan. Each address pointer comprises an entry for every VDU scanning line and determines which dot video line signal will be used in that scanning line by specifying the data row address in the page memory (29) and the dot matrix row number to be used by the generators (26 and 27). Such address pointers enable complete control over the display for the purpose of defining windows, scrolling the display smoothly and slowly at the rate of one scanning line per frame and smooth expansion of a strip on the display by dulplication of lines.

Abstract: The head is formed by a container (2) comprising a rigid frame (14, 16) of tapered shape, bearing the nozzle (4) at one end thereof. Fitted into the frame is a tubular membrane (47) for containing the ink, which is sealed at the other end of the frame by a metal plate (51) connected to an electrode (6) in contact with the ink. The frame is provided with openings (58) to permit the membrane to keep the ink at atmospheric pressure. The electrode (6) is formed by a blade spring in contact with the metal plate (51) and is provided with a projection (42) disposed in a chamber (30) in the vicinity of the nozzle to maintain contact with the ink right up to exhaustion of the cartridge. The head is removably fixed in a seat on a carriage by means of lever which urges the head into its seat and also serves as electrical contact with the metal plate. A second contact is made to an electrode on the front of an alumina plate (3 ) in which the nozzle (4) is formed.

Abstract: The method consists in analyzing phonemes of the phonetic signal at regular intervals of time, comparing the phonemes with a series of reference phonemes, selecting the reference phoneme closest to the phoneme of the phonetic signal and generating a visible indication of the selected phoneme in real time on a monitor (20) to allow the speaker to adapt his speech to the response of the apparatus.The apparatus comprises a series of analyzers (A.sub.1, A.sub.2 . . . A.sub.n) for a phonetic signal segment for generating a series of vectors (V) to be compared by a set (13) of comparators (C.sub.1, C.sub.2 . . . C.sub.m) with a plurality of reference vectors corresponding to the various reference phonemes.A control unit (19) receiving the result of the comparison controls the visual display on the monitor (20) of a histogram indicating the selected phoneme and also a merit value (P) and a stability value (ST), of the recognition.

Abstract: A device for detecting the level of a liquid contained in a tank, for example the level of the fuel contained in the tank of a motor car. The device comprises a vertical bar inserted in the tank and a float movable with respect to the bar to follow the variations in the level. The bar, which is of insulating material, acts as a supporting element for a printed circuit having at least one continuous conductive track and a variable resistor parallel to the continuous track. On the float there is mounted a metal element which simultaneously contacts both the conductive track and the variable resistor.

Abstract: A print element is actuated by a piezoelectric transducer controlled by a circuit which is capable of emitting a pulse in such a way that the reflection waves arising from expulsion pressure in the conduit for the ink are cancelled. The transducer is also connected to a circuit for detecting the pressure of the ink during the printing operation. A circuit for detecting the malfunctioning is capable of storing and signalling both the presence of bubbles in the conduit and the conduit empty condition. For bubbles, a flip-flop in the malfunction detecting circuit stores a signal indicating the presence of reflection phenomena when control circuit is operated for cancellation of the reflection waves. For the conduit empty condition it stores a signal indicative of the absence of reflection phenomena when the control circuit is operated in such a way that cancellation of the reflection waves does not occur.

Abstract: One or more printing elements in tube form with a capillary nozzle at one end are mounted in aligned and mutually parallel relationship with a cavity in a support. The printing elements have piezoelectric sleeves thereon and are embedded in a filling of polymerised resin which fills the cavity. They are disposed in such a way that the nozzles project externally from the support while the other ends communicate with a common ink reservoir. The upper wall of the reservoir at each tube is arched with the highest region aligned with the corresponding tube in such a way that any bubbles in the ink can be easily expelled by way of the nozzles. A capillary filter separates the chamber of the reservoir from an ink feed conduit to prevent impurities or air bubbles from passing therethrough. In another embodiment, the reservoir is partitioned into a plurality of separate chambers to ensure that emptying of one tube does not affect operation of the adjacent tubes.