Abstract: The inked element which is preferably in ribbon form comprises a flexible plastics carrier of a thickness of from 5 to 15.mu., covered with a thermotransferable coating which is 2 to 6.mu. in thickeness. The mixture of the coating comprises a blend of thermoplastic resins of non-polymeric type with natural or synthetic waxes with a melting point of between 60.degree. and 80.degree. C. The waxes and the resins are so selected as to be compatible with each other and to provide a melting point of between 60.degree. and 80.degree. C. and a melt viscosity of between 50 to 1000 cps. The ribbon makes it possible to print at a printing rate of 40 to 120 characters/sec on papers having a Bendtsen roughness of 10 to 100 ml/min. The ribbon can be prepared with bands of different colors for multi-color printing.

Abstract: A recording and reproducing apparatus for magnetic discs, each one contained in a protective case (23), comprises a frame (11) having a front slot (20) for the insertion of a case (23). The disc case (23) slides into a support unit (30) spaced above a driving hub (81) and a magnetic head (90) mounted on a carriage (91). The support unit (30) is urged downardly by springs (37) but is held in the raised position by pins (32, 33) trapped in slots (54) of tongues (50 to 53) upstanding from a slider (45). The disc case engages a lever (70) which turns clockwise and engages a lever (61) to turn this also clockwise. The lever (61) disengages from an edge of the slider (45) which moves forwardly under the action of a spring (48) to free the pins (32, 33) and allow the support unit (30) to drop down vertically, guided by the pins (32, 33) in vertical slots (34, 35). The lever (70) may additionally push a cover of the disc case laterally to uncover slots (24) in the disc case.

Abstract: A device for reading graphic symbols impressed on a sheet, comprising light sources for illuminating the sheet, an optical reading system and an array of photo-electric sensors for generating electrical reading signals. The device is compact in structure and of small dimensions, so as to allow it to be mounted upon the head-carrying carriage of a printing machine or typewriter. The device makes it possible to create, in a particularly simple form, reading apparatus for facsimiles or for optical character recognition (OCR) reading apparatus for memorizing signatures, graphical symbols and drawings or mathematical symbols, or apparatus for copying documents.

Abstract: The apparatus is for recording and reading binary information on a magnetic disc (14) of rigid type, with a plurality of concentric recording tracks. Each track comprises a useful zone for storing binary information and a function zone in which information which is used for correct positioning of the head with respect to the central axis of the track is pre-recorded. Moreover, in the function zone of a predetermined track, information identifying this track as a reference track is also pre-recorded. A stepping motor (22) is adapted to position the magnetic recording and reading heads with respect to the tracks of the disc and is driven by a circuit which comprises a voltage source (51) and a voltage boosting circuit (53) which supplies the stepping motor (22) with a voltage (PA) higher than that (PW) supplied by the voltage source (51) during the presence of a command signal (RC) which is emitted by a control unit (15) during the time required to shift the heads from an existing position to a new position.

Abstract: A head (13) comprises a closed container (15) carrying internal (139) and external electrodes and a nozzle (18) and is mounted removably on a carriage (14) on which it is held by a permanent magnet (43) in such a way that the head bears with the external electrode against a metal sheet (32). The magnet is of an annular shape and is carried by the carriage. It attracts a metal plate (39) in the bottom of the container, which carries a pin (41) for centering the head on the carriage and is utilized to make connection to the internal electrode (139). A protuberance adjacent the nozzle (18) presses against the metal sheet (32) which in turn presses the paper (11) against a platen (10). The protuberance establishes the jet-to-paper spacing.

Abstract: An ink jet printer is provided with an ink reservoir including a laminar substrate covered on the outer surface of a plurality of metal coatings forming individual electrodes associated with a plurality of nozzles. These latter are formed of holes passing through the substrate and the coatings. An additional metal coating is provided in the inner surface of the substrate and includes a portion to provide a common electrode and a plurality of portions connected with the coatings of the outer surface. The reservoir has a chamber for the evacuation of gases which form during the printing operation, the chamber having an associated Venturi pump acting as a vacuum source.The electrical energization circuit for the printer includes an adjustment member for effecting controlled variation in the energy of the pulses which cause the ejection of ink sprays through the printer nozzles.

Abstract: The apparatus for manufacturing the ink jet glass tubes includes a vertical mandrel which receives the tubes one at a time from a feeder and rotates them relative to a pair of gas nozzles for their heating. The tube is heated in an axially limited intermediary zone so as to form an hour-glass shaped profile.The profile of the tube is scanned by a television camera which generates two signals indicative of the internal diameter. These are compared electronically with a stored indication of the desired diameter and the two nozzles are rotated into an inactive position when this diameter is reached. The tube is cut along a plane so as to make the profile of the nozzle coincident with a reference profile by a device including an optical device connected to a cutting wheel to permit comparison of the hour-glass profile of the element with the reference profile. The severed end of the tube is then lapped and covered with a non-wettable material.

Abstract: An apparatus for rotating a magnetic disc provided with a central hole and an entrainment opening comprises a hub member which is mounted on the shaft of an electric motor and which is provided with a flat surface on which the magnetic disc can be supported. The upper end of the shaft projects with play through the central hole in the disc. An entrainment peg which engages with the opening in the disc is fixed to one end of a movable arm which has the opposite end pivoted on the hub member. The entrainment peg is housed with play in a hole in the hub member and can move radially to center the disc with respect to the shaft of the motor, by virtue of a reaction force (F) imposed on the disc.

Abstract: The ribbon (17) has an external run between the type element (25) and platen of a daisy-wheel typewriter. This run stretches between terminal members (59) which protrude from side arms (33 and 34) of the cartridge casing (18) and are fixed to the distal ends of arms (39, 41) pivotally mounted in the casing (18) at (52). The arms (39, 41) are biased downwardly by wire springs (67) to expose the typing line. Ribbon lift levers of the typewriter raise the arms simultaneously to position a selected one of three tracks on the ribbon at the level of the typing point. The terminal members (59) slide on guides (62) at the ends of the side arms (33, 34), constraining the external ribbon run to lie always within and translate within a single plane. The edges of the guides (62) are curved so that the tilt of the terminal members (59) varies as they move up and down, in such a way as to maintain the ribbon tension uniform across the width of the ribbon (17).

Abstract: A transparent case (11) for a binder has a substantially parallelepiped form lacking one face and is made of transparent material. The lower support wall (17) of the case includes a wedge-shaped element (22) the sides of which project some millimeters inside the container. The sides (26, 28, 29) face the side walls (13, 14) of the case and are so connected as to spread the covers of the binder when it is introduced into the container. The wedge-shaped element (22) also has side faces (26, 27) parallel to the side walls (13, 14). The side faces (26, 27) space apart the binder covers so as to render them parallel and adjacent to the side walls (13, 14) of the container. This allows perfect viewing and reading of whatever writing or representation is on the covers of the binder and the best retention of the binder within the case, even when the binder contains few sheets.

Abstract: The optical transducer is connected to a rotary shaft (71) for detecting the angular position thereof and generates corresponding electrical signals. The transducer comprises a casing formed by two casing halves (11, 12) which can be assembled together by means of latch elements (62, 63). Mounted on a first casing half (11) are three phototransistors (31, 32) for detecting the light emitted by a diode (58) mounted on the other casing half (12). A shutter disc (64) which is provided with radial openings is mounted rotatably within the casing on the shaft (71) which is supported by a self-aligning bush (19) which is mounted on a casing half. A flexible printed circuit (38) is disposed within the first casing half, parallel to the shutter disc and is in contact with the three phototransistors. The printed circuit has a projecting portion (43) which is bent over inside the casing so as to contact the diode (58) and a projecting portion (39) which extends out of the casing to be connected to an external connector.

Abstract: A contact keyboard comprising a plurality of modular keys individually insertable in a base frame having feet adjustable in height in order to permit a variable inclination of the key plane. The back feet are pivoted on a shaft internally to lateral sides of the base frame and are provided with edges engaging the support plane for the base frame. The edges have extensive planar portions lying at different distances from the shaft for regulating the inclination of the key plane. The angular position of each back foot is stabilized by a corresponding spring supported by the pivoting shaft and which urges the foot against an associated lateral side of the base frame and causes one of a plurality of notches of the foot to be engaged by a tooth of the associated lateral side of the base frame.

Abstract: A steel core (16) is subjected to an anti-adhesion passivation treatment. The nozzle (10) is then deposited by electroforming on the core of a layer of metal of predetermined thickness. After the tip (13) of the electroformed nozzle has been faced to uncover the capillary hole, the core (16) is extracted with an apparatus which comprises a plate for retaining the print nozzle and an extraction gripper. The electroforming bath may be formed by a solution comprising nickel salts.

Abstract: A trichromatic photosensor scans an image to be reproduced repeatedly to generate, for each elementary area scanned, signals indicative of the chromatic characteristics of this elementary area. The photosensor is connected to a trichromatic printer controlled by the signals produced by the photosensor for printing corresponding colored dots on the paper. During successive scanning operations, the photosensor is moved relative to the color image and the printer is moved relative to the paper. These relative movements are coordinated with each other so that the photosensor and the printer act simultaneously on corresponding regions of the color image and of the paper. In one embodiment the printer is stationary and is capable of printing in parallel the dots of one line. The paper circulates along a closed path to be sequentially printed according to the various color components. In another embodiment the printer is of the serial type.

Abstract: The carriage of a digital document reader is shifted by means of a pair of worms rotatable in the frame and engaging two nuts borne by the carriage. The worms are rotated simultaneously, e.g. by a single stepping motor and a toothed belt engaging a pulley or by two separate stepping motors. For the purpose of reducing inertia, each worm is formed together with the driving pulley by moulding a layer of plastics material on a metal core tube which is formed with a shallow groove of coarse pitch to anchor the plastics layer. Each nut, also of plastics material, is formed with a series of axial notches which define an equal number of elastic sectors which allow any play on the worm due to wear to be taken up.

Abstract: An optical transducer for detecting the position of a rotary or translatory member comprises a light source, a photodetector group, and a shutter provided with a series of transparent elements spaced by opaque regions and interposed between the light source and the photodetector group. The photodetector group comprises an integrated circuit, on a surface of which is disposed a plurality of photovoltaic cells, each having an area which is a fraction of the area of each transparent element. The cells are divided into four groups to generate as many electrical signals which are out of phase relative to each other by 90.degree. and which are indicative of the position of the shutter with respect to the position of the photodetector group and the light source. The cells are disposed symmetrically with respect to a central radially extending optical axis, and in such a way that the barycenter of the areas of each of the four groups is included in the central optical axis.

Abstract: A cartridge for a typing ribbon and spools for a correcting ribbon are mounted on a common frame which can tilt about a spindle. In a lowered position of the frame the typing line behind a daisy wheel is visible. The frame is raised by a first stroke to the position shown to dispose the typing ribbon over the typing point on the platen. A longer stroke raises the correcting ribbon to the typing point and this longer stroke also actuates an automatic ratchet wheel and pawl type of feed mechanism for the correcting ribbon. The two strokes of the frame are controlled by a disc comprising two cam tracks with a common part and separate parts having different degrees of eccentricity relative to the common part.

Abstract: A serial printer comprises a carriage (21) which is movable parallel to a platen roller (11) and on which are mounted a character carrying disc (28) having a flexible blades, a stepping motor (26) for selecting the character to be printed, and a striker hammer (30, 31). The carriage is slidable on a cylindrical guide (17) and is provided with a pair of slider members (62, 63) which co-operate with a fixed bar (18) that is parallel to the guide (17) and to the platen roller (11). Mounted on the fixed bar (18) at the left-hand side of the printer is a key (70) which can co-operate with the slider members (62, 63) of the carriage to disconnect them from the bar (18) and to permit the carriage (21) to be swung down so that the character carrying disc (28) can be easily removed and replaced.

Abstract: A device for controlling the rotary movement of a platen roller of a typewriter comprises a bidirectional electric motor coupled to the platen by a worm gear and gear wheel and a pair of knobs which are disposed at the sides of the platen and which are rotatable with respect thereto. The knobs are fixed to a bar which extends rotatably through the platen roller and carries the gear wheel. Selective bidirectional rotation of the knobs causes corresponding rotary movement of a disc in a transducer. The disc has a toothed sector in mesh with the gear wheel and is the moving part of a rotary switch which generates electrical signals which determine both the power supply to the electric motor and the direction of rotation thereof. Small degrees of rotary movement of the knobs against a first spring force establish continuous rotary movement of the platen roller at low speed. A further slight rotary movement of the knobs against a stronger spring force establishes rotary movement of the platen at high speed.

Abstract: The apparatus is of the type wherein a piezoelectric transducer (19) is selectively operated to produce a pressure wave in the ink in a duct (16, 22), which causes a droplet of ink to be expelled from the nozzle (18). In order to absorb the energy of the pressure wave which is directed towards the ink reservoir (47) the duct comprises a portion (22) of viscoelastic material, which is so dimensioned as to damp the resonance of the duct for frequencies higher than a predetermined cut-off frequency. Frequencies which are lower than the cut-off frequency however are damped by an hour-glass shaped constriction (34) in a tube (33) disposed between the viscoelastic portion (22) of the duct and the reservoir (47). The second portion (22) of the duct comprises a polyamide base material, the modulus of elasticity of which is substantially stable over a wide range of possible operating temperatures.