Abstract: A tractor feed for paper webs with margin perforation for use in printers of data processing systems in which endless bands support feed pins engagable with said perforations to effect paper transport toward, around and away from a platen. Upper and lower runs of the endless band and feed pins supported thereby are selectively adjustably movable into and out of paper guide slots to facilitate introduction and loading of the paper web. The band is movable by movable upper and lower guide rails which are controlled by an adjusting mechanism and by springs acting to spread said guide rails apart.

Abstract: A key operated switch for keyboards having a layer type construction of key support carrying printed circuits arranged to facilitate fully automatic production of keyboards. Further, the simple formation of a leaf spring, a key guide and the key stem comprising the switch enables these parts also to be assembled by machine. The simple and hence inexpensive manufacture of a keyboard utilizing the key operated switches causes no loss of operating quality.

Abstract: A single pass ink ribbon cassette for typewriters or like machines is designed to track ribbon extending between a supply and take-up spool in such a manner that text contained on used ribbon beyond a point of impression is rendered illegible. Used ribbon is rendered illegible in that upon its entry into the cassette, it is guided around a turn around roller for passage past the point of impression a second time before re-entry again into the cassette, and conducted via guide means for take-up by a driven take-up spool. Due to the fact that the ink ribbon is guided past the point of impression a second time, subsequent impressions on the used ribbon render the text from the used ribbon unreadable. In addition, in the zone of the turn around roller a scraper is provided for scraping the residual ink particles off the used ribbon before it is guided past the point of impression the second time.

Abstract: Mechanism for automatically adjusting the feed increment according to the type of ribbon in a ribbon cassette is characterized by a pawl and feed ratchet and to means operative by coded features on a cassette, when the cassette is mounted, to control the interval of engagement of the pawl and feed ratchet.

Abstract: Mechanism to raise and transport print and correction ribbons in typewriters and similar machines as a function of the direction of a rotation of a motor. The required motions are brought about by means of a cam wheel containing different cams and by appropriate cam followers, and provision is made to maintain ribbon raised to the typed line level so that during rapid printing only transport steps need to be carried out. It is also possible with the mechanism to effect transport steps of different size, to meet the requirements of the ribbon type used.

Abstract: Elastic bearings supporting bearing bushings for shafts are mounted in recesses in plates of a machine frame. The elastic material is shaped so that, in at least one predetermined direction transverse to the longitudinal axis of the shaft, its dimension is a multiple of that in other directions. What is achieved thereby is that the shaft is constrained to move in one defined direction only.

Abstract: A wire print head is provided with piezoelectric drive elements in the form of strips which are bonded to flexible tabs directed radially inward from a support ring. The ring is secured between a wire guide structure and a cover and the curved surface of the wire guide structure opposite the flexible tabs is grooved whereby contact of the piezoelectric elements on the flexed tabs and the risk of breakage thereof is avoided. The drive ends of the print wires supported in the wire guide structure are directly driven by the ends of the flexible tabs and have no contact with the piezoelectric elements. Further the cover is provided with electrode guards having slots to dissipate heat generated in the flexible tabs.

Abstract: Apparatus for lifting print and correction ribbons in typewriters or printers having a bidirectional motor for driving a lift lever coupled to lift, according to the direction of rotation, either the print or correction ribbon, as required. In order to be able to use a relatively weak motor, the lifting movements of the lift lever driven directly by the motor are transmitted directly to the print or correction ribbon guides without interconnecting members. Print ribbon feed is implemented by means of camming surfaces on the lift lever operating to feed ribbon during the return movement of the print ribbon to rest position below the printing line.

Abstract: An assembly for mounting deflection rollers about which a belt extending between machine side walls is trained comprises plug-in parts which enable the deflection rollers to be assembled one to one machine side wall, and the other to a guide plate supported by and adjustably spaced outwardly of another side wall with the spacing establishing belt tension which holds the assembly together. The guide plate also mounts a detector for monitoring the rotary position of the deflection roller.

Abstract: Disclosed is a method for destroying used carbon ribbons so that individual carbon ribbon segments are formed by cutting with a knife. The used carbon ribbon is wound spirally on the reel by axially moving the reel during a winding process and by maintaining this motion during a cutting process. A multitude of individual carbon ribbon segments with cut edges running obliquely to the longitudinal edges of the carbon ribbon are thereby produced.

Abstract: Information stored in a working memory of a word processor comprising symbols representing alpha-numeric text characters and word processor functions are displayed by means of a line display unit with alpha-numeric text characters and function symbols each occupying only one display position on the line display unit.When the meaning of a function symbol identified by a cursor positionable to identify the next display position to be processed is not evident, its meaning is automatically displayed in leftmost positions of the display unit, with suppression or shift of the text already displayed in said leftmost positions taking place as necessary to display the meaning of a function symbol.

Abstract: An easily produced and assembled one piece connector adapted to be detachably fastened to a movable carriage, for example the movable carriage of a printer. The connector is formed of various parts which can be folded relative to one another and joined together to secure plug connections between a flexible flat band cable and electrical motors or electromagnets on the carriage, and to retain and secure the flat band cable adjacent to its plug connection so as to provide tension relief.

Abstract: An improved ribbon lift mechanism for alternately raising a ribbon from a lowered position to first and second elevations relative to a print line. A ribbon lift lever is raised by a cam ring having alternating high and low lift cams separated by valleys for acting on a cam follower directly connected to the ribbon lift lever. The cam ring is indexable by a cyclically movable powered lever which acts to control a locking lever to lock the raised ribbon lift lever at said first and second elevations and to release it for return to lowered position incident to a cycle of the powered lever. The arrangement allows an economy of parts and operation by a relatively weak power source.

Abstract: A flexible member is mounted in an inked ribbon cartridge such that it presses a high friction pad against a cartridge wall between a ribbon entry aperture, and the nip of a take-up spool and an associated drive wheel, thereby to apply a drag force on and to smooth out ribbon passing between the pad and cartridge wall in advance of winding on the take-up spool.In one embodiment a cantilever member formed with the cartridge is flexed by a cam on the cartridge cover to produce pressure on the friction pad secured to the member. In another embodiment, the member is wedged between spaced abutments in the cartridge such that overcentering action applies pressure to the friction pad.

Abstract: An image conversion apparatus has a line array of light responsive circuits connected in parallel across a voltage source. Each circuit comprises the capacitance of an elemental area of a photoconductive insulating layer arranged in series with a capacitor which is shunted by a normally open switch. The levels to which charge is distributed in the capcitance of the photoconductive insulating layer and in its associated capacitor is related to the quantity of light incident on the elemental area of the photoconductive insulating layer over intervals an associated switch is open. Closure of a switch serves to discharge its associated capacitor and to cause the capacitance of the photoconductive insulating layer to charge to the voltage of a source from a lower level obtained during open switch intervals. The magnitude of the charging current is related to the quantity of light incident on the elemental area of the photoconductive insulating layer.

Abstract: The invention relates to a mechanism for raising and lowering a ribbon in front of the typing area of a typewriter or similar machine. The mechanism is so designed that only a few lightweight plastic parts need be moved thereby greatly reducing the actuating force necessary to elevate a ribbon. The mechanism also is configured to track the ribbon such that deformation of the ribbon as could impair proper functioning of the lifting and/or transporting of the ribbon during the ribbon lifting motion is minimized.

Abstract: An engage/disengage coupling between a drive and driven part for imparting rotational force without axial force components.

Abstract: A keyboard is pivotally mounted on a pull out shelf to be raised from a reference position to desired angles of inclination within a range of angles, and is associated with apparatus for positively locking the keyboard following movement of the keyboard to a desired angle of inclination and its release; with the weight of the keyboard acting to maintain locking action. The apparatus effecting the locking action comprises a toothed segment whose arc and teeth define a range of angles. Associated with the toothed segment is a supporting arm biased to follow upward keyboard movement and on which the keyboard after being raised to a desired angle of inclination rests.