Abstract: The printing device has, in addition to a line feeding device mounted upstream of the printing line to make the sheet advance incrementally, an extraction mechanism mounted downstream of the printing line in order to enable printing without smudging until the trailing edge of the sheet; the extraction mechanism including a couple of robber rollers and opposed pressure rollers having fine external teeth, which are selectively engaged, when the trailing edge of the sheet reaches a determined position, by means of cam driven levers.

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: 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: 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: 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 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 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: 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: A line spacing device for printing machines comprises an electric motor arranged to rotate selectively in a clockwise direction and anticlockwise direction and a control disc carrying a pawl on an eccentric. The tooth of the pawl describes a closed trajectory engaging in the teeth of a wheel and of a sense the same as the rotation of the disc, whereby a paper support platen is rotated by one increment in the opposite sense. A central control unit controls the clockwise and anticlockwise rotations of the electric motor. A cam disengages a detent pin from the wheel so that the motor is only lightly loaded when actuating the platen.

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.