Abstract: An electronic typewriter has an electronic control circuit housed with the usual typing mechanism in a casing, and can be provided with a display module for displaying text and/or machine functions. The display module is removably fixed to the casing. An electronic unit for controlling the display module is removably fitted in the casing and is connected to the control circuit and the display module by connectors. A basic typewriter without a display module can be constructed with a cover instead of the display module. The two types of typewriter can be produced on largely the same production line, and the basic typewriter can be simply upgraded with a display module in the field.

Abstract: An electronic typewriter (11) has a line spacing device (29) for rotating a platen roller (16) and a transport device (28) for moving a printing carriage (19) in both directions. The line spacing and transport devices are driven from a single motor (32) via an intermediate gear (40) mounted on a shift member (35). The shift member (35) is displaceable between two operative positions for connecting a driveshaft (33) to the transport device (28) or to the line spacing device (29). A servomechanism (36) which is motorized by the shaft (33) displaces the shift member (35) between the two positions by means of a shift electromagnet (81) which actuates a lever (79) to lock the gear (40) by means of teeth (88) on a slide member (43). Positioning means (44) hold the shift member (35) in each of the two operative positions, and an electronic control means (22) controls the motor (32 ) and the electromagnet (81). The system is of low cost, and is simple, functional and reliable.

Abstract: A unitary cassette for a typewriter comprises a container and two arms. The container comprises two support elements and which project from the bottom and which are capable of rotatably supporting a supply spool and a take-up spool for a correction ribbon. Two guide elements projecting from the ends of the arms guide a portion of the ribbon below the typing ribbon, and a tensioning device holds the ribbon taut. The cassette can be mounted on a carriage of the machine by means of two projections projecting from the underneath of the bottom and which are capable of being pivotally mounted in two respective grooves and moving against two co-operating surfaces for oscillating movement about an axis parallel to the roller. A pin on one side of the container can be removably engaged into a seat of a connecting lever of the machine, which is connected to a displacement means.

Abstract: A feed arrangement for a typing ribbon and/or a correction ribbon comprises a linear motor having a coil-carrying slide which is movable with an alternating rectilinear movement, a toothed wheel for the feed movement of the ribbon, and a connecting mechanism interposed between the coil-carrying slide and the wheel for converting the movement of the slide into a unidirectional rotary movement of the wheel for advancing the ribbon. The connecting mechanism comprises a first lever which is moved by the slide and two mutually independent ratchet assemblies and which are capable of alternately engaging with two diametrally oppositely disposed teeth on the toothed wheel. The ribbon is carried by a cassette and the wheel rotates a blade capable of engaging into a seat in a feed roller of the cassette.

Abstract: A cartridge for a typing ribbon for typewriters comprises a container for accommodating a typing ribbon which can be of single-strike correctable or non-correctable, multi-strike or endless inked type. If the ribbon is of the single-strike or multi-strike type, the container comprises a supply reel and a tensioning and stop device co-operating with a toothed flange of the supply reel to prevent the ribbon which is wound on the supply reel from unwinding both when the container is mounted on the machine and when it is removed from the machine. The device comprises a tensioning lever for the ribbon and a stop lever for the reel, which levers are connected together by means of a resilient spring connection. The device guides and tensions the ribbon during the unidirectional feed movement thereof, in such a way as to ensure a constant stepping movement in the feed motion of the ribbon and low and constant tensioning of the ribbon.

Abstract: An electronic typewriter has a reduced number of electrically-powered actuators and comprises a motor powering a differential motion transmission unit having first and second output members. Transmission control means powered by a solenoid moves a slider to engage stop members selectively with the first and second output members to permit the second and first output members respectively to rotate. The first output member drives the carriage transport mechanism. The second output member drives the character carrying element and also powers function devices, namely a correction device, through a motion switching mechanism controlled by a switch control mechanism including another solenoid. The typing ribbon feed is driven by reciprocation of the slider between its two states. The motor is mounted on the frame and drives the motion transmission unit on a carriage through a belt; it also drives a line spacing mechanism through a clutch operated by a further solenoid.

Abstract: In a thermal ink jet print head the ink is expelled in the form of small drops through a plurality of nozzles communicating with corresponding expulsion chambers for expulsion of the ink through the effect of rapid heating of heater elements contained in the expulsion chambers. The nozzles, the expulsion chambers, the heater elements and the associated electrical conductors are constructed in a plurality of metal layers and insulating layers supported by a silicon plate. The plate is fixed to the structure of the head and is supplied with ink contained in a movable cartridge fitted to the structure of the head. The cartridge comprises a rigid reservoir containing a sponge saturated with ink which can be hydraulically connected to the head by means of a needle-type conduit mounted on the head and which perforates a rubber membrane of the cartridge.

Abstract: A striker device for use in printers comprises a platen roller, a character-carrying disc and a print hammer for striking a character of the disc against the roller. The print hammer is actuated by an armature which is movable in an impact direction by virtue of electromagnetic excitation of a stator body. The device includes strike-silencing means comprising sliding guide surfaces between the print hammer and the armature, which ensure freedom of movement for the armature with respect to the hammer in the impact sense and direction, and a ring of elastomeric material which is interposed between the armature and the print hammer and which transmits the kinetic energy of the armature to the print hammer with a delay. Particular ratios between the masses `Mh` and `Ma` of the hammer and the armature and between the levels of hardness `Kr` and `Kp` of the elastomeric ring and the roller provide a single but prolonged strike on the part of the print hammer.

Abstract: A cassette for a printing ribbon for typewriters comprises a casing accommodating a supply spool, a receiving spool and a brake and take up device which operates on a tube of the supply spool and on the ribbon which is unwound from the supply spool. The tube is rotatable on a sleeve projecting from the bottom of the casing. The brake and take up device comprises a shoe for applying a braking action to an internal surface of the tube. A wire spring has an intermediate portion which engages in a seat of coupling means of the shoe. In a first position the shoe is urged against the surface of the tube and brakes the supply spool. In a second position the shoe is spaced from the internal surface of the tube and the supply spool is free to rotate. The spring also performs the slack ribbon take-up function and for that purpose comprises an end having an L-shaped bent portion which in turn is engaged with the ribbon to regulate the tension and unwinding of the ribbon which is unwound from the supply spool.

Abstract: The paper pressing arrangement comprises a paper guide plate for guiding a sheet of paper around a platen roller towards the typing line. The paper guide plate comprises two conveyor modules each of which supports three paper pressing rollers and is provided with a pivot element projecting from the barycentre of the triangle joining the mid-points of the three rollers. A control mechanism, in an operative position, transmits by means of a rocker lever pivotally connected to the pivot elements the action of a spring to urge the conveyor modules against the roller. The control mechanism comprises a lever for positioning the two conveyor modules in an inoperative position to permit insection of the sheet of paper. Each conveyor module defines a first axis for rotation of two front paper pressing rollers and a second axis spaced from the first axis for rotation of a rear roller disposed intermediate each pair front rollers.

Abstract: A needle or wire printing head comprises a plurality of electromagnets with fixed cores, each with two limbs, which are mounted in a ring within a containment body. Movable armatures are disposed in a radiating array in front of coplanar terminal surfaces of said cores. The movable armatures each have a step configuration for oscillating on the terminal surface of the more outward limb, a surface for closing the magnetic flux which, with the terminal surface of the more inward limb constitutes a main air gap "G" and an end capable in printing of engaging a needle by means of a corresponding limb. A unitary return group accomodates a plurality of coil springs in a prestressed state for restoring the movable armatures. There is also provided a magnetically conductive conveying disc of ferro-magnetic material and comprising a plurality of spokes for closure of the magnetic flux which is common to the armatures and the cores.

Abstract: The contact-type keyboard comprises a plurality of keys which are movable from a rest position to an operative position and which each have a sleeve capable of being accommodated in a tube provided on the upper part of a dome portion of elastomeric material. Each dome portion projects from a mat and, below the tube, comprises an internal circular ring provided with a movable conductive portion for short-circuiting a corresponding fixed conductor of a printed circuit which in turn is carried by a stop plate of insulating material. Each sleeve is of such a length as to pass internally by way of an upper opening through the dome portion, to engage a through hole in the plate to project downwardly beyond the plate and comprises a seat capable of accommodating a corresponding pin of a support frame structure so as to guide the respective key from the rest position to the operative position and vice-versa.