Abstract: A matrix printing device includes a housing body which can effect a translational movement relative to a printing surface in use, a plurality of wires slidable in the housing body and each having one end for acting on the print surface as a result of a thrust exerted on the other end, and a plurality of oscillating operating members each of which can exert a thrust on a respective wire. Electromagnetic excitation circuits selectively oscillate each of the operating members from a rest position to a position of thrusting the respective wire. The operating members are fixed to a single resilient support element. The position of fixing of each operating member to the support element and the resilient properties of the support element determine, respectively, the path of oscillation of the operating member and the degree of resilient force which returns the member to the rest position.

Abstract: The head (12) comprises a closed container (14) carrying two electrodes (36, 62) and a nozzle (18) and mounted removably on a carriage (13).In order for the ink (16) always to be held at atmospheric pressure, the container (14) comprises an expansible space defined by a diaphragm (67) having a portion (74) aligned with an opening (73) in the container (14).The diaphragm (67) is of butyl rubber which can be pierced with a syringe to permit the container (14) to be refilled with ink (18).The container (14) is closed by an alumina plate (32) carrying the nozzle (18) and joined to a second plate (76) parallel thereto, and of a material which can be wetted by the ink (16). The second plate (76) constitutes a wall for resisting the pressure waves of an ink jet leaving the nozzle (18), and is immediately covered by the ink again.

Abstract: The apparatus comprises an electronic teleprinter constituted by a first set of basic peripheral units such as the printer, keyboard etc. as well as a punch/reader, arranged to converse directly with the line and controlled by a first central unit, and a second set of peripheral units such as a disc unit, one line display and VDU controlled by a second CPU and able to execute more sophisticated operations such as the automatic filing of messages, their display etc. The two CPUs each autonomously control their own peripheral units with simultaneous processing, and periodically communicate with each other for the exchange of data and commands by way of an interface in an auxiliary unit. The CPU of the basic machine is thus free to handle the basic input/output procedures without having to service the auxiliary peripherals.

Abstract: The head comprises at least one nozzle (38) associated with two electrodes and carried by a holder (14) into which an ink cartridge (50) can be fitted. The cartridge is filled with ink and sealed after it has been filled. The cartridge terminates at one end with a cylindrical portion (60) which is closed by a diaphragm which can be ruptured upon insertion in the head. The diaphragm is ruptured by a tube (66) which projects within the holder and which communicates with the printing nozzles (38). The cylindrical portion (60) of the cartridge is offset with respect to the longitudinal axis of the cartridge to ensure correct insertion thereof. At the other end the cartridge is closed by a cover (87) having an aperture which is disposed above the free level (PL) of the ink and which is initially closed by a second diaphragm.

Abstract: The cartridge comprises a container (7) of substantially parallelepipedal form with its corners radiused and rounded off. The container is provided with a back (8) having a slot (27) adapted to guide a slide (26) on the ends of which are rotatably mounted a feed spool (22) and a take-up spool (32) on which the ribbon (21) is wound. A spring (36) engaged with a stud (41) on the slide keeps the slide (26) towards the right-hand side of the container with the take-up spool (32) engaged with the pin teeth of a feed roller (42). As the turns of ribbon wound on the take-up spool increase, the slide shifts with the two spools towards the left-hand side of the container in opposition to the action of the spring. The cartridge is mounted removably on a support of the machine which is inclined with respect to the horizontal plane of the machine passing through the printing point in a manner such as to permit visibility of the printed characters.

Abstract: Mounted within a substantially hollow supporting and containing housing are tubes which communicate at one end with an ink reservoir and whose opposite ends are aligned with respective ink discharge nozzles provided in a plate member which faces the printing surface in use. The plate is mounted on the housing so as not to touch the ends of the tubes and with the interposition of yieldable sealing members. The tubes are mounted in the housing with the aid of a positioning tool the shape of which reproduces essentially the shape of the plate. A resin is subsequently poured into the housing and, after hardening, constitutes an elastic mass for retaining the tubes in the housing.

Abstract: A line spacing mechanism for printing machines comprises an electric motor which is operable to rotate selectively in either direction. A worm on the shaft of the motor meshes with a helicoidally toothed wheel to cause a platen roller to rotate in the clockwise direction or the anticlockwise direction. The motor is support pivotally by trunions and urged by a spring to eliminate radial play between the worm and toothed wheel. Another spring, lever and ball apply thrust to the motor shaft to take up axial play in its bearing, i.e. between the worm and the motor.

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: Connection is effected by piercing the insulation of the cable by a pair of needles (36) connected to the circuit and disposed parallel to one another at a distance slightly less than the diameter of the central conductor (19) of the cable, so as to come into contact with the conductor at two diametrically opposed regions. The parts of the needles which pass through the screening braid (21) of the cable are covered with insulation (44).Two other pairs of parallel needles (52) are disposed symmetrically either side of the first pair and are arranged in pairs at a distance corresponding to the diameter of the screening braid. All the needles are disposed on a jaw (15) adapted to receive the cable, against which a second jaw is closed when actuated by a two-position lever. This is connected to the second jaw by connecting rods which in the closed position are moved beyond a dead point.

Abstract: The converter comprises an output transformer (T1) through which pass trapezoidal current waves. The primary winding (A0) is supplied under the control of two control circuits (P1, P2), each comprising a transistor (Q1, Q2) and a diode (D1, D2) which are connected in anti-parallel. The two transistors are controlled by two oppositely-poled secondary windings (W1, W2) of a second transformer (T2), the primary winding (W3) of which is controlled by the first transformer (T1). Associated with each control circuit (P1, P2) is a capacitor (C1, C2) such as to accumulate energy during one phase of operation and to discharge it during a subsequent phase. Another winding (Wc) of the second transformer (T2) permits the latter to be biased, stabilizing the output voltages by means of closed-loop feedback control of one thereof.

Abstract: The device comprises two or more cover plate members (14), whose lengths are submultiples of the lengths of a range of platen rollers (12) and such that two or more plate members disposed in side-by-side relationship cover the entire length of the platen roller. Each plate member (14) comprises a lower guide portion (16) of part-cylindrical shape and two wall portions (17, 18) which are substantially planar and set at different angles of inclination, being connected to the lower guide portion in such a way to lead in a sheet of paper (19) towards the guide portion. Each plate member (14) is pivotally mounted on a control shaft (22) which is parallel to the axis of the roller (12) and capable of preventing transverse movements of the plate member with respect to the roller, and carries the usual paper pressing rollers (34, 36) which are disposed in two parallel rows. A leaf spring (26) co-operates with a lug (24) on the plate member (14) to hold the paper pressing rollers pressed against the platen roller.

Abstract: A direct-current electric motor (29) used for, for example, positioning a printing device in an office machine, is controlled by an arrangement comprising a microprocessor (40) which causes the motor digitally to perform accelerations and/or decelerations to maintain it close to a desired speed programmed in relation to the distance to be completed. Control between the actual speed of the motor and the desired speed is effected utilizing the timing signals (FTA, STB) generated by a transducer (35) connected to the motor. During a first phase, the microprocessor compares the times taken to complete a series of angular steps of rotation, the steps following a schedule of decreasing size with stored reference times and effects accelerations and decelerations of durations proportional to any discrepancies.

Abstract: The electronic typewriter is of the `daisywheel` type and comprises a microprocessor, a stepping selector motor controlled by a position register for positioning the daisywheel 28, and a support frame for a correction ribbon. The support frame is arranged to oscillate from a down position for viewing purposes to an up position for the correction operation. A tab (104) moves up and down with the frame. The daisywheel rotates together with a sleeve member 97 provided with a stop seat 98. The tab (104), in the up position, urges a tooth (99) on a lever (101) into interference with the sleeve member (97), via a resiliently yielding blade (107) of the lever (101). During the correction cycles, rotary movement of the daisywheel (28) takes place when the support frame and hence the tab (104) is in its own position and thus without any obstacle. In the initialization phase, the microprocessor raises the support frame and tab (104) in advance of a command for complete rotation of the daisywheel (28).

Abstract: A ballistic type wire printing head comprises a metal front support (11) for guiding the printing wires (23) and supporting a group of actuating electromagnetic units (37, 39, 41) associated with the wires. The armatures (41) of the electromagnetic units are pre-assembled on a disc (40) of plastics material. A rear cover (59) which is also of metal encloses the electromagnetic units and in its interior supports spring spider (58) which co-operates with all the armatures of the electromagnetic units. The electromagnetic units have a common internal, ferromagnetic support (35) from which heat is conducted to the front support (11) and cooling fins (25). In a second embodiment, the printing head also comprises a second group of electromagnetic units associated with another series of printing wires. In that case, an intermediate metal member acts as a cover member for the first group of electromagnetic units and as a support for the second group of electromagnetic units.

Abstract: An apparatus for recording flexible magnetic disks contained in envelopes comprises a mandrel engageable with a central zone of the disk to rotate the disk within the envelope, and a carriage 41 which is movable radially relative to the disk and on which there is mounted a pair of magnetic heads which oppose each other and make contact with the magnetizable surfaces of the disk. The upper head is carried by a support (85) movable on the carriage and urged by a first spring (87) toward the disk. A presser pad, which presses the envelope containing the disk against a reference surface of the appartaus, is lowered by an electromagnet which also causes the upper head to lower. A lost-motion form of coupling enables the pad and upper head to carry out independently adjustable travel strokes, so minimizing any recoil.

Abstract: A contact-type keyboard comprises a plurality of modular keys and a support panel (11) provided with openings (12) in which the keys are inserted. Each key is provided with a pair of resilient tongue portions (51, 52) which lock it to the panel (11) and which are deformable to permit the key to be easily removed from the panel (11). Each key further comprises a resilient system formed by a dome-shaped spring and a coil spring, which are interposed between a movable actuator and the subjacent conducting parts of an electrical circuit.

Abstract: The typing and erasing device is applied to a printer of the daisywheel type and comprises a carrier (84, 86) for a typing ribbon (32) having a plurality of transverse tracks which can be selected for the printing operation and a carrier for an erasing ribbon which is disposed parallel to but at a different height from the typing ribbon. The typing ribbon is contained in a cartridge on which two typing ribbon carrier arms (41) are pivoted. The carriers oscillate vertically in order to render visible the typed characters and for the operations of typing or erasing the characters at the typing point (12).

Abstract: The apparatus comprises a dot printer (24) and a control unit for the printer connected to the line in parallel with a video display, the control unit is capable of processing the data received and storing it temporarily in a page memory in transcoded form in such a way as to associate with each character the relative print attributes and to be able directly to address a character generator. The control unit is capable of taking the transcoded data from the page memory for controlling the printer. The character generator comprises a portion for the alphanumeric characters, a portion for semigraphic characters and a portion for decoding colors with a corresponding grey value. The semigraphic characters are produced on a matrix of 10.times.12 dots in such a way that, for each grey value, the horizontal and vertical distance of the character dots of the same color remains constant.

Abstract: The head is provided for a conductive ink (16) and comprises a container (14) having a capillary nozzle (18) where the ink is in contact with a pair of electrodes facing each other across the nozzle, in such a way as to be covered by a predetermined depth of ink between the electrodes and the meniscus (52) at the front end of the nozzle. Printing is effected by vaporization of a portion of ink in a section of the nozzle between the electrodes, which expels the said depth of ink. The container is closed by an insulating plate (30) over which extends a metal strip (37) of smaller width than the diameter of the nozzle. The nozzle is formed by means of a single hole through the plate and the strip, whereby the strip is separated into two electrodes. The metal strip may be disposed between the plate and a front dielectric layer 43.

Abstract: The head is provided for a conductive ink in contact with an electrode (34) and comprises a container (14) having a capillary nozzle (18, 53) and a counterelectrode (54) set into the nozzle that predetermined thickness of ink is in the front part (53) of the nozzle between the meniscus (52) and the inner part of the nozzle wherein a vaporizing current flows between the electrode and the counterelectrode, thereby to expel the said thickness of ink. For that purpose, the container is closed by an insulating plate (30, 31) on which the counterelectrode (54) is disposed, the counterelectrode in turn being covered by a dielectric layer (56). The nozzle is formed by means of a single hole through the plate, the counterelectrode may be of the same thickness as the said thickness of ink, so that the front part of the nozzle is all through the counterelectrode.