Abstract: A printer having a printing head provided with a plurality of printing elements disposed substantially along a line, a cylinder supporting a print sheet such as a sheet of paper held by an edge clamp and an ink ribbon changer. Four ink ribbons, for example, are contained each in a cartridge removably attached to a support and indexing mechanism. The support and indexing mechanism of ink ribbons and providing an accurate multi-color printing.

Abstract: An electrothermal printer having a print head provided with a plurality of wire electrodes, an ink ribbon, and a heating ribbon separate from the ink ribbon. The heating ribbon is in the form of a layer of material which is a poor conductor of electricity and a layer of electrically conductive material. The current passing between one or several of the electrodes in the print head to the heating ribbon conductive layer which is in contact with an appropriate sliding contact or electrode heats a localized area, or localized areas, of the heating ribbon which in turn transfers heat to corresponding localized areas of the ink ribbon for transferring ink on a sheet of paper. The ink ribbon and the heating ribbon are displaced at the same speed past the print head. The printer of the invention permits high rate printing at a relatively low cost of supplies. With the ink ribbon omitted, printing can be effected directly on thermo-sensitive paper.

Abstract: A sheet feed device for a printer or typewriter having a plurality of cassettes supporting stacks of sheets to be printed, a sheet removal mechanism associated with each cassette for removing a sheet from the cassette and positively driving the removed sheet to a position for feeding it into the printer, and a selection mechanism for actuating a selected one of the sheet removal mechanism.

Abstract: The multicolor thermal printer comprises a frame (1), a platen (4) and a carriage (2) that can move along the platen (4). This carriage (2) consists of a lower part (5) carrying the thermal print head (3) and an upper part (6) hinged to the part (5) thanks to a hinge pin (7a). The upper part (6) carries four inking ribbons (31) located on levels of height increasing from the front to the rear so that the inking ribbons are arranged in a vertically offset fashion on the ribbon guides (40). By pivoting of the upper part (5), the ribbons can be placed successively opposite the heating elements (3a). A drive mechanism (53 to 68) for the ribbons is made so as to drive only the ribbon placed opposite the heating elements (3a) and only when the carriage (2) is moved in the direction of printing.By this design, a fast change of the printing color and a reduced consumption of inking ribbons can be attained.

Abstract: The cassette comprises a bottom (25) and four side walls (26 to 29) comprising on their upper edge holding elements (14) for the sheets. These sheets are placed on a support plate (41) held near one of the corners (33) in contact with the bottom (25). Three springs (44 to 46) pull the plate (41) in the direction of the holding elements (14). A locking mechanism (50) consists of a sliding part (51) comprising near its ends two openings (54) able to work with two flathead pins (52) solid with the plate (41) to hold the latter against the bottom (25) in the vicinity either of the corner (31), or of the diametrically opposite corner (32). The same cassette can thus be introduced in the lengthwise or widthwise direction, which makes possible a saving in cassettes and in sheets.

Abstract: A typewriter comprises a carriage (1) sliding parallel to a platen (3). The typing device (2) operates in a printing zone which is displaced along this platen (3).The casing (7) of the machine is open above the platen (3) and has a transparent anti-noise hood (10) covering its opening (8).In order to facilitate the reading of the last line of type across the hood (10) which absorbs a part of the light, the typewriter is provided with means for illuminating the platen (3). These illumination means are constituted by electric bulbs (17) either carried by a transparent slide (14) housed in a U-shaped throat (12) or lie in the direction of the platen (3).

Abstract: The sheet feed device (1) comprises several cassettes (13) on which the sheets are stacked, a removal mechanism associated with each of the supports, intended to remove a sheet from the cassette (13) and introduce it into the printer (2), and a selection mechanism (55) intended to activate one of the removal mechanisms. The mechanisms for removal and selection (55) are driven by the platen (3) of the printer (2). The selection mechanism (55) makes use of the position occupied by the mobile carriage (4). The latter carries a drive part (61) that can work with a set of selection levers (56). These levers (56) are equal in number to the removal mechanism. Depending on the position of the carriage during selection, one or the other of the levers (56) is put into active position and moved by a drive wheel (65) to activate a removal control element (76) and to start the removal and introduction processes.

Abstract: The sheet feed device (1) comprises several cassettes (13) on which the sheets (11) are stacked, a removal mechanism, associated with each of the supports, intended to remove a sheet from the cassette (13) and introduce it into the printer (2), and a selection mechanism intended to activate one of the removal mechanisms. This selection mechanism consists of a guide part (72) comprising several tracks (73 to 75) and a selection lever (56) made to engage with the top of guide part (72). When the platen (3) of the printer (2) turns in the direction opposite the direction of introduction of the paper, the selection lever (56) is driven in the same direction. After a rotation of a predetermined angle, greater than two turns of the platen, the direction of rotation is reversed. The lever (56) follows one of the tracks (73 to 75) to activate one of the removal control parts (76 to 78) and to start the removal and introduction process.

Abstract: The detection means for the ends of a ribbon for typewriters includes a light flow conductor member 17 integral with the bottom 2 of the case for the ribbon cassette. The member 17 has two light guides between which the ribbon passes. One of the guides is disposed in a manner to induce flow of light emitted by the light source opposite light source 15 opposite the ribbon, the other is disposed in such a manner as to conduct to the detector 16 the flow of light traversing the ribbon. Thus, the placing of the ribbon is facilitated and the optical reader does not risk damage when it is put in place. Since a new light conductor member is disposed in the light flow each time the cassette is changed, the detection of the end of the ribbon is not adversely affected by harmful deposits.

Abstract: A cartridge for a dye-impregnated endless ribbon includes a transport device disposed within the cartridge; the transport device includes a driving member having a surface, and a stationary member having another surface so that the surfaces define a passage for the ribbon. Friction-generating devices are disposed near the surface of at least one member and in contact with the ribbon, causing the ribbon to move only in one direction through the passage. A drive device is provided and may be operated to move the driving member with respect to the stationary member.

Abstract: The needle writing head comprises a support in two parts (5 and 6), each comprising recesses (15, or 18) forming guide paths for needles (16) located along two rows. The part (6) is movable parallel to the row of needles (16) over a distance equal to one-half of the distance between centers of the needles (16) so as to make it possible to place the needles of the second row in alignment or staggered in relation to the needles of the first row. Means (19 to 26) consist of notching means to fix the two relative positions of the parts (5 and 6).The latter (5 and 6) are rubies and the part (5) is in two parts (12and 13) glued at (14).

Abstract: A pivotal rod, in the form of a flat bar, extends through an axial bore of a sleeve, pivotally mounted on a sliding carriage. A coupling member connecting the rod to the sleeve comprises a slide pivoted on the sleeve around a pivotal axis perpendicular to the axis of rotation of the sleeve and sliding along the rod. The coupling member includes three ball bearings, two of which bear on the edges of one of the surfaces of the flat bar and the third bears against the other surface in the longitudinal axis of the flat bar. The bearings are mounted on pivots oriented parallel to the pivotal axis of the coupling member. This mechanism ensures an angular coupling without play between the rod and the sleeve and is usable even when the displacement of the rod or the trajectory of the carriage or their parallelism to each other is not perfect.

Abstract: A decimal tab mechanism for a typewriter of the type having a printing element carried by a carriage comprises a tab bar 1 capable of being displaced longitudinally and comprising a series of tab blades 2 which may be separately selected. A stop 19 of bar 1 is capable of cooperating with a decimal tab stop 67 placed in active position from an assembly of decimal tab stops 67.Said mechanism further comprises an apparatus 28, 35-41 for driving bar 1 longitudinally ahead in the direction of typing, a cam 28 for the placing in active position of the selected tab blades 2 before longitudinal displacement of tab bar 1, and connection means 50-62 between a drive shaft 29 and the assembly of decimal tab stops 67 comprising devices 51, 53, 54 for assuring that a selected decimal tab stop 67 is placed in active position only after longitudinal displacement of tab bar 1.

Abstract: In the typewriter driving of the platen (1) is effected by the motor shaft (3) which operates a character selection device. This motor shaft (3) and the platen (1) occupy predetermined angular positions at rest.During a driving command of the platen, a part (26) brings a transmission pinion (22) into mesh with the last controlled pinion (9) of a gear train (5 to 9) coupled to the motor shaft (3) before this shaft is actuated by the motor (4). The transmission pinion (22) is secured to one end of the transmission shaft (16, 19, 20) and the other end of the shaft carries a toothed wheel (15) in mesh with a driving pinion (14) secured to the platen. The angular notching of the pinions and their number of teeth is provided in such a manner that the teeth of the pinion (22) engage exactly between the teeth of the controlled pinion (9).

Abstract: A shock absorption thrust mechanism includes a thrust piece (19) which is used as a stop for a moving body in motion. This thrust piece 19 is prone to displacement under the effect of kinetic energy of the moving body, against the action of a spring (20) and a shock absorber (21). The displacement of the thrust piece (19) depends on the kinetic energy of the moving body under shock, which is prejudicial particularly with respect to typewriters, where this displacement occurs in the stop position of the moving body or ensures the control of a function. In order to obtain a constant displacement of the thrust piece (19), the mechanism includes a driving device (10, 24) which moves the thrust piece (19) in a predetermined movement, the driving device (10, 24) acting jointly with the moving body on the thrust piece (19).

Abstract: A cassette comprises a casing (1) containing a delivery spool (2) and a receiving spool (4) co-operating with drive means. The ribbon (3) passes from the delivery spool (2) to the receiving spool (4) outside the casing (1). The delivery spool (2) is secured to a toothed wheel (20) which co-operates with a catch (23) of a part (21) biased by a spring (28). This part (21) in the form of a T, is pivotally mounted on the casing (1) at one of the upper ends of the arm or crosspiece of the T and carries return roller (24) at the other end of this arm around which roller the ribbon (3) is diverted in a manner to form a loop. The length of the upper arm of the part (21) is substantially twice as large as the distance separating the catch (23) of the pivot point of the part (21). This arrangement ensures a correct tension of the ribbon ( 3) at all times.