Abstract: The present invention relates to a printing apparatus, and more particularly to an arranging structure in which an ink ribbon extended from a ribbon cassette is arranged between a platen and a print head. The printing apparatus comprises a platen rotatably supported on a frame, a print head capable of moving reciprocally along the platen, a ribbon cassette replaceably loaded at one end side of the movable range of the print head and housing an ink ribbon with some portion extending outwardly as a loop, and a ribbon guide body located inside the loop of the ink ribbon and for pulling out the same. The ribbon guide body is movably provided along the platen and enters inside the loop of the ink ribbon when the ribbon cassette is mounted on the frame with the ribbon guide body located at one end side of the movable range of the print head.

Abstract: For compensating for the lateral displacement of the ribbon (4) during the print operation in impact printers with revolving type carriers (9), an inclined pivotable roller (1) is used which is taken along by contacting the moving ribbon. This roller has a pivot (10) with a free end pivotable between two stops (11,12). If there is no lateral ribbon displacement to be compensated for, the pivotable roller is arrested in its respective current position and thus prevented from rotating. In the event of a ribbon displacement (LS), the pivotable roller rotating about its axis exerts a force component (LO) on the ribbon, counteracting the lateral displacement (LS).

Abstract: An inherently rugged multi-color dot matrix impact printer having a yoke type optical code detector assembly mounted on the neck portion of an impact dot matrix print head through which a multi-colored print ribbon passes. The print ribbon is configured in alternating vertical segments of selected colors of ink which have top and bottom photo-optical code regions on the outer edge of the ribbon. Coding comprises the presence or lack of an aperture in the form of a hole which is adapted to pass light therethrough and which is aligned with each ink segment. The yoke additionally includes upper and lower light emitter/sensor pairs for sensing the coded aperture pattern to control the presence of a predetermined colored segment of printing ribbon in front of the print head.

Abstract: A printing device for use in a wire dot printer having a plurality of printing wires. The printing device includes a frame and a carriage slideably supported on the frame for lateral translation thereacross. A print head is supported on the carriage and includes a nose portion which supports the plurality of printing wires. First and second holders are disposed on the carriage so that the nose portion is intermediate the first and second holders. A ribbon mask constructed from a resilient material is disposed on the nose portion. The ribbon mask is held in position by engagement with the first and second holders. The carriage includes a projection extending towards the ribbon mask. The ribbon mask is further supported by the projection. In addition, the ribbon mask may include a plurality of projections which extend towards and abut against the nose portion to keep the surface of the ribbon mask spaced from the nose portion to permit travel of an ink ribbon therebetween.

Abstract: An erasing ribbon is guided by the same vibrator as the typing ribbon behind the lower part of the typing ribbon. An erasing key acts on the back-spacing mechanism of the typewriter and on an element which suppresses the carriage escapement during a correction cycle initiated by any one of the typing keys. The necessary settings are made by a slide which stores the erasing key command. In particular, the slide acts on a lever which varies the stroke of the ribbon vibrator for selecting the erasing ribbon, also on a device which causes the erasing ribbon to advance and on a mechanism which inhibits the escapement during the execution of the correction cycle. The setting slide is then returned to rest by the first typing key operated after the erasing cycle. A correction selection lever acts on the lever which varies the stroke of the ribbon vibrator and selects permanently the erasing ribbon independently of the erasing key for a forward erasing of the characters of one or more words.

Abstract: The printing and correcting device is applied to a daisywheel printer and comprises a frame supporting a cartridge for a typing ribbon and a correcting ribbon arranged below the typing ribbon. The frame is able to swing as the result of operation of an electromagnet, from a rest position providing visibility of the print, to an intermediate position for printing the characters. A second electromagnet raises the frame through a greater length of travel in order to position the correcting ribbon in front of the printing point. A rotating electromagnet causes automatic unidirectional advance of the typing ribbon after each character has been printed. The correcting ribbon is wound between two spools and its motion is provided by means of a pawl which engages with a gear wheel for driving the spool only in the case where the path of travel of the frame is greater than that which relates to positioning of the typing ribbon.

Abstract: A resilient ribbon mask for an impact printing apparatus which includes a print head is mounted for sliding movement on a frame connected to the print head. The frame and mask are angled away at either side of the print head from the surface of the platen along which the print head travels in a line printing operation. A slot in the mask for allowing passage of printing elements therethrough is oriented with its long dimension parallel to the direction of print head travel, and extends into the angled portions of the mask on each side of the print head so that the slot ends do not engage the record media being printed upon. The ribbon mask is held in close proximity to the print head during printing operations, but is permitted to spring away from the print head at the end of a line being printed, in order to facilitate ribbon changing and record media insertion and removal.

Abstract: A printing device for use in a wire dot printer having a plurality of printing wires. The printing device includes a frame and a carriage slidably supported on the frame for lateral translation thereacross. A printing head is supported on the carriage and includes a nose member which supports the plurality of printing wires. First and second holding members are disposed on the carriage so that the nose member is intermediate the first and second holding members. A ribbon mask constructed from an elastic material is disposed on the nose member. The ribbon mask is removably held between the first and second holding members and extends across the nose member.

Abstract: A frame-supported disposable ribbon supply and take-up cartridge for typewriters and printers of the type employing a carriage-transported printing device is equipped with a constant path length ribbon guiding and directing structure which can be collapsed and folded for compact packaging and which can also be factory pre-threaded to eliminate any need for the operator to fit a ribbon leader around any guides on the print carriage. One form of the invention uses twin one-way articulated ribbon guides which are connected by a ribbon directing bar and are each orthogonally pivoted to the sides of the cartridge for collapsing, rotating, and folding against the sides of the cartridge. The other form uses a single two-way articulated ribbon-guiding structure pivoted to the cartridge and having a second articulated structure, all of which can be folded against the sides of the cartridge.

Abstract: A disposable ribbon carrier for use with a stenograph reporting machine having a printing station, an ink spool supporting station and a pair of laterally spaced narrow feed channels normally providing a ribbon transport path between the printing station and the supporting station. The ribbon carrier includes a pair of arm members which extend between the printing station and the supporting station. A central portion joins the end of each arm member adjacent the ink spool supporting station. Each arm member has a first portion diverging outward from the ink spool supporting station toward the printing station, and a second portion extending from the termination of the first portion to a terminating end adjacent the printing station when the ribbon carrier is installed in the reporting machine the second portions being mutually parallel and dimensioned to be received in the narrow ribbon guide channels.

Abstract: Apparatus for guiding an ink ribbon for a printer, with top edges standing perpendicularly to and inclined forward toward the printing plane, over which the ink ribbon laid on flange plates which act as slides when fed further and threads in itself. At the same time means for the quick fixing of the print head are provided on the apparatus serving for the guiding of the ink ribbon.

Abstract: The printing and correcting device is applied to a daisywheel printer and comprises a frame supporting a cartridge for a typing ribbon and a correcting ribbon arranged below the typing ribbon. The frame is able to swing as the result of operation of an electromagnet, from a rest position providing visibility of the print, to an intermediate position for printing the characters. A second electromagnet raises the frame through a greater length of travel in order to position the correcting ribbon in front of the printing point. A rotating electromagnet causes automatic unidirectional advance of the typing ribbon after each character has been printed. The correcting ribbon is wound between two spools and its motion is provided by means of a pawl which engages with a gear wheel for driving the spool only in the case where the path of travel of the frame is greater than that which relates to positioning of the typing ribbon.

Abstract: A tape cassette for use with a thermal printing apparatus includes a cassette housing; supply and take-up reels rotatably mounted in the cassette housing; tape having a pigment thereon wound about the supply and take-up reels and having a segment extending between the reels, the length of the segment being adjustable; a hollow projecting portion extending from the cassette housing and having a free end at which a first guide pin is connected; a second guide pin moveably mounted, in a sliding or pivotal relation, with respect to the cassette housing for guiding the segment of tape; and optionally, a tape drawing member to which the second guide pin may be connected and which is moveable with respect to the cassette housing for adjusting the length of the segment of tape.

Abstract: A separator plate for a type band printer is located between the print paper and a ribbon so as to prevent the ribbon from contacting the paper. The upper edge of the separator plate is located adjacent to the print line and pushes the paper away from the ribbon against the hammer plate. The separator plate is affixed to the printer.

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: A multicolor imprinter employs a plurality of heat transferable tape of different colors wound upon one another in continuous convolutions on a supply reel which has its axis of rotation parallel to the direction of travel of the tapes through a marking zone. A guide structure is provided between the supply reel and the marking zone to turn the tapes so that they are parallel and coplanar as they traverse the marking zone. A separate takeup reel is provided for each tape and has an axis of rotation perpendicular to the direction of tape travel.

Abstract: A ribbon cartridge in a movable print point printer remains stationary while the ribbon moves to and from the print point along a path of fixed length. The path length is established by a first flexible leader which extends from the cartridge to the print point and a second flexible leader which extends from the print point back to the cartridge. The cartridge includes a supply reel for storing ribbon before the ribbon advances to the movable print point and a take-up reel for storing ribbon after it returns from the movable print point. The flexible leader comprises a steel member having a transverse curvature for preventing the leaders from assuming a reverse curvature and maintaining a curvature of substantially constant radius.

Abstract: A ribbon cartridge for high speed printers having a main ribbon storage casing and a pair of arms which extend in generally the same direction from the casing. The ends of the arms form an exposed ribbon path to allow the printhead to strike the ribbon. A shield is provided in front of the ribbon to prevent the accordion folds of the paper from engaging and lifting the ribbon out of the path of the printhead.

Abstract: A cassette for storing a ribbon having a top portion and a bottom portion. The top portion has a front area having a print station area thereat and a rear area, and also has a first resilient arm having one end extending from the front area to the rear area and also having a free end. A ribbon supply reel is rotatably supported on the first arm and the top portion also has a second resilient arm formed therewith having a free end which engages the rim of the supply reel to form a drag thereon. The ribbon from the supply reel passes around the free end of the first arm, around a ribbon usage sensor, to the print station and is withdrawn back into the cassette by a take up reel located underneath the supply reel, with the take-up reel driven by a spindle.

Abstract: A ribbon lift and feed mechanism for a typewriter/printer (10) in which the print ribbon cartridge (15) has deflectable arms (16a, 16b) for placing the ribbon (13) in a position confronting the platen (11) of the typewriter (10). On the platform (40), supporting the ribbon cartridge (15), is a shuttle (50) which is remotely oscillated as by a drive motor (90) on the frame (12) of the typewriter (10). Translation of the shuttle (50) and the cam (66) associated with the shuttle (50) effects movement of cam follower (66a) engageable with the cam (66), causing the deflectable arms (16a, 16b) of the cartridge (15) to oscillate between a rest and elevated position to place different portions of the print ribbon (13) intermediate the type element (23) and the platen (11). The shuttle (50) also carries ribbon feed drive means (85) which cause an incremental feed of the ribbon (13) after the ribbon has been struck at multiple elevated positions.

Abstract: In thermal printing the guide (29) positionable toward the platen (3) on a pivoted arm (50) during lift-off correction allows a bond for correction to set before the ribbon (22) is pulled away. The ribbon (22) has an outer layer which adheres to printed characters at somewhat elevated temperatures but is non-tacky at room temperatures. Thermal printing is conducted by setting the switch (44) for heating to temperatures higher than the lift-off temperature.

Abstract: A printing cartridge for supplying image carrying tape and printing ribbon in a printing apparatus including a cartridge housing comprising a tape and ribbon supply section and an elongated guide section rigidly and integrally joined with the supply section, a spool of image carrying tape rotatably supported within the tape and ribbon supply section and a supply of printing ribbon disposed within the tape and ribbon supply section. The printing cartridge also includes a wall section for retaining the spool of image carrying tape in a generally circular configuration, a device for limiting the movement of the image carrying tape from the tape and ribbon supply section in a forward direction only, an improved guide structure for guiding the tape and ribbon through the elongated guide section and an improved structure for aligning the cartridge with respect to a cartridge carrier.

Abstract: A plastic ribbon guide to fit on a print head of a mosaic printer. The printer is a ticket printer which holds the ribbon in a stable position adjacent the tray which also acts as an anvil. The ribbon is kept taut. The ribbon guide has a shape to hold the ribbon in a positive manner.

Abstract: The cartridge comprises a container in which a feed spool 22 and a take-up spool 24 for the ribbon 19 are rotatable. The cartridge is provided with a lateral arm 14 which guides the ribbon between the container and the typing zone 23 and with a distance piece 25 between the container and the arm 14 which disposes the ribbon above the typing point 17 at a higher level than that of the container in order to allow viewing of the characters along the typing line. The distance piece 25 comprises deviation surfaces 56, 57 which constitute a friction device for the ribbon emerging from the container.

Abstract: An improved ribbon shield for use with a ribbon cassette in a printer. The shield snaps into the front of a ribbon cassette so as to cover an exposed portion of ribbon and prevent the smudging or wicking of ink onto a printing medium. The ribbon shield includes an elongated strip of flexible material such as polypropylene having a central aperture to enable the ribbon to pass through it for printing purposes. The shield includes a lower curved lead-in portion to accommodate paper motion past the cassette. The shield is held within the ribbon cassette in a flexible state. The flexed portion of the shield contacts the printing medium and forces it into close contact with the platen. Improved performance can be obtained by providing spacing ridges in the form of rings which surround the aperture.

Abstract: A cartridge for an inked ribbon for type bar typewriters comprises a container adapted to be mounted on one side of the printing point and a terminal part which guides a length of ribbon to the printing point and reverses the direction thereof for reentry of the ribbon into the container. Two return surfaces of the terminal part carry the ribbon reentering the container back at the same height as the emerging ribbon. The container is of elongated shape and is mounted removably on a support on the machine which rocks in front of a platen in such manner that the terminal part of the cartridge is disposed below the printing line. There is provided a mechanism for actuating the inked ribbon which comprises a control element actuatable by the type bars and a toggle joint which rock the cartridge support for effecting a precise raising of the ribbon in response to variable stroke control actuated by the selected key.

Abstract: A printing apparatus of the type having a printing station, a printing force exerting and resisting means, an image carrier and a font element with a raised character and a tape-ribbon cartridge therefor. The improvement of the present invention relates to an improved device for exerting a printing force and an improved tape-ribbon cartridge for supplying tape and ribbon to the printing station and for guiding and supporting the font element into printing alignment.

Abstract: A printer subsystem receives command and data information from a host system and retains a large number of font images in an associated storage area within the printer subsystem. A base font image set is ordinarily selected by the user but provision is made to dynamically change the font images as may be required in a real time fashion during actual printing operations. The font images are stored in a compressed form in the storage area. Routines involve use of pointer tables and data tables. It is possible to select an entire set of new font images in place of the base set of images or to modify only selected character images within the base font image set.

Abstract: A ribbon loading system for a printer of the kind having a moveable printhead carrier establishes a ribbon loading position for the carrier at one end of the carrier travel axis. In response to an operator initiation, the printhead carrier is driven to the loading position where the ribbon cartridge is operator mounted at a fixture adjacent the printhead. The cartridge includes a path defining section that extends to arrange a loop of ribbon around the distal side of the printhead, effectively threading the ribbon. Subsequent carrier movement is selectively coupled to the ribbon to provide ribbon drive motion.For a preferred cartridge implementation, the path defining section is detachable to travel with the printhead carrier and includes ribbon guides for defining at least a portion of the ribbon path around the printhead during printing. The preferred detachable section is held to a bulk ribbon supply section of the cartridge by a catch which is automatically released by mounting the cartridge.

Abstract: An improved flexible leader particularly suited for use in conveying the ink ribbon from a ribbon cartridge to the print point of a printing machine or typewriter is disclosed. Preferably, the leader is formed as an integral member having discontinuities therein defining bending points at which said leader is flexible. The leader can be flexed in only one direction, whereby the inked surface of a typing ribbon is never in contact with said leader, thus preserving its integrity.

Abstract: In a printing machine having a removable ribbon cartridge, means are provided for conveniently loading and unloading said ribbon cartridge on a support plate. Said means include guide means within the cartridge which cooperate with complementary guide means within the support plate for guiding the cartridge while it is being dropped-in onto the support plate; and lever operated cam/cam-follower means for then shifting the cartridge on the support plate to its final locked position. The cartridge unloading is performed through a reverse lever operation followed by a cartridge pick-up.

Abstract: A printhead assembly for a typewriter of the kind that swipes a printhead along a ribbon in producing marks on a receiving medium, is mounted to pivot and includes a ribbon guide that serves to wrap the ribbon around the trailing side (for a forward printing direction) of the printhead. The assembly is positioned to permit the printhead to be rotated to a normal printing position at a printing line. By so arranging the ribbon path that the ribbon directions for arrival and departure of the assembly intersect the pivot axis, essentially zero resultant torque may be applied to the assembly by ribbon tension forces and the printing pressure at the receiving medium is, accordingly, unaffected by ribbon tension variations.

Abstract: In an endless inked ribbon cartridge wherein an inked ribbon received in a chamber is drawn out from the receiving chamber by a guide arm and then fed into the receiving chamber by another guide arm, and the inked ribbon is exposed between the guide arms for printing, a guide plate is disposed which covers the exposed inked ribbon except a part necessary for printing, thereby to prevent the inked ribbon from staining fingers or paper and from severing accidentally.

Abstract: A microcomputer controls a ribbon drive assembly in a high speed wire matrix printer to eliminte ribbon slack, to insure proper ribbon positioning and to conduct diagnostics in conjunction with turning on the printer such as start-up time each day and after replacement of the ribbon with a new ribbon, the diagnostics checking to be sure that a ribbon is actually in the proper position, that it is threaded across the print line and also checking for proper operation of the ribbon drive, logic, and electronics. Tests are also made for proper ribbon drive during normal ribbon feeding operations.

Abstract: In a printing apparatus having a platen, a plurality of print hammers arranged in a horizontal row and a horizontally movable type carrier on which print carriers are arranged, a restraining member limits upward movement of a horizontally movable ink ribbon and thereby eliminates character omission. Between the print hammers and the type carriers are disposed the horizontally movable ink ribbon and a vertically movable print sheet on which a character impression is made upon impact of a selectively energized hammer. The print sheet is folded along transverse cut lines to define forms which are stacked together below the apparatus. When the print sheet is pulled upwardly, the folded portion tends to drag the ink ribbon upwardly displacing the ribbon from its print position. The restraining member is mounted above the ink ribbon to limit this upward movement of the ribbon.

Abstract: A printing ribbon guiding and re-inking means is positioned to guide a continuous looped printing ribbon through a 180.degree. twist between the exit and entry points of a ribbon cartridge. The guiding and re-inking means includes a twist-locator or arrestor comprising a pair of opposing elongated flanges, for passing a ribbon therebetween, positioned between the exit and entry points of the ribbon cartridge to positively locate the twist in the ribbon in a particular area along its path of travel. This prevents movement of the twist into other areas and other ribbon-carrying mechanisms, where the twist could cause jamming or undesirable ribbon twisting. A spool support means integrally coupled to the flanges carries a re-inking spool which both applies ink to the ribbon and guides the ribbon between the flanges and the cartridge. The spool orients the transverse position of the ribbon to be substantially the same as the transverse position of the ribbon at the entry to the cartridge.

Abstract: A high-speed printer, such as a daisy wheel printer, utilizes a carriage which transports a printing font, such as a daisy wheel, laterally along a print line adjacent a paper-supporting platen. An ink ribbon is supported on the machine frame rather than the printing font carriage and is positioned between the daisy wheel and the platen. This ribbon is adjusted so that, as the printing font progresses along a print line, it impacts the ribbon along the line which is slanted relative the lengthwise axis of the ribbon. When plural such slanted printing tracks are overlapped along the length of the ribbon, efficient use is made of the ribbon without incurring problems associated with a narrowed ribbon. In addition, the slanted ribbon impact line permits the ribbon to be mounted on the machine main frame rather than on the font carriage while still permitting a minimum of over-impacting on the ribbon, all while eliminating the requirement of rapid ribbon movement during carriage return.

Abstract: An improved flexible leader for web transport is disclosed which features ribbon enclosing tabs bent up from a flat sheet so as to prevent reverse bending of the leader thus preventing contact of a delicate side of said ribbon with the leader or the remainder of the ribbon supply structure.

Abstract: A ribbon cassette for a looped ink ribbon in a stuffed state is provided with a depending plate on a lower surface of a cover member, for covering a ribbon chamber, near an outlet opening in order to reduce a ribbon drawing-out force by taking advantage of a slight and not-excessive frictional resistance taking place there. The depending plate is in the form of an inverted isosceles triangle and the distance between the tip end of the triangle and a floor of the ribbon chamber is smaller than the width of the ribbon.

Abstract: A stuffed ribbon cartridge for a serial impact printer includes flexible leaders for guiding the ribbon from a stationary storage position to a movable print point. In order to place tension on the ribbon which is stored in the cartridge in a stuffed condition, a clip which pinches the ribbon so as to produce a drag force on the ribbon is located adjacent the print point and spaced from the cartridge by a substantial length of the flexible leader.

Abstract: This invention relates to location of thin ribbons or webs with respect to predetermined locations. More specifically, the invention relates to improved ribbon locating budge whereby an inked typewriter ribbon is located in proximity to an impact hammer for impacting the ribbon into a paper or other print receiving medium.

Abstract: An improved ribbon tensioning means is disclosed in which a spring-loaded gear rack is in engagement with a gear wheel formed on a spool of tape to be unwound. The gear rack is provided with sufficient travel in the direction opposite to that of the spring force that the teeth thereon can be disengaged from those on the gear wheel if the wheel is rotated a sufficient distance, thus constantly providing tension to a tape or ribbon wound on the spool.

Abstract: In a ribbon cartridge for retaining and supporting a ribbon in a typewriter, the cartridge comprising spaced apart top and bottom walls and a sidewall joining the top and bottom walls adjacent the periphery thereof to form a chamber. The sidewall of the cartridge is discontinuous at predetermined locations to form at least entrance and exit apertures for the ribbon, and at least a ribbon take up spool is provided in the chamber in communication with the ribbon entrance aperture to take up used ribbon passing through the entrance aperture.

Abstract: Disclosed is an assembly for threading a ribbon, preferably an erase ribbon through an impact printer such as a typewriter. One end of the ribbon is stored at a ribbon storage means, while the other end of the ribbon has a tab fastened thereto. The longitudinal dimension of the tab is perpendicular to the longitudinal dimension of the ribbon and the tab contains a frangible portion which is used for finger engagement during the threading operation. The ribbon take-up reel contains a slot in one of the flanges thereof such that the ribbon tab may be inserted into the slot after the ribbon has been threaded through the printer. The frangible portion is then separated from the ribbon and discarded.

Abstract: A ribbon exit control, for a random stuffing ribbon cartridge is disclosed which prevents the accidental jamming of the ribbon at the exit port of the storage chamber. The exit port is formed by two mating members whose surfaces are configured, when mated, to form a slot of curvelinear shape such as the form of an arc of a circle or an angled relatively flat lazy V shape. An alternate form is a slot punched in a one piece member to define the slot. The deformation of the slot from that of a straight line causes the ribbon to buckle as it is pulled from the storage chamber and to assume a cross-section other than that of a straight line. This acts to separate the ribbon strand being removed from the chamber, from any other adjacent folds of the ribbon. Since the ribbon strand and the adjacent folds are separated by the deforming of the ribbon it is more difficult for an adjacent fold to be pulled into the exit gate thereby causing a jam.

Abstract: Disclosed is a ribbon cartridge for an impact printer, the cartridge having a housing in which a print ribbon is stored. A segment of the print ribbon is situated outside of the housing and is positioned adjacent the print point by means of a rigid bridge means which spans the print point and which is mounted to bridge piers located on the print element carriage. The bridge means greatly facilitates the mounting of the ribbon cartridge.

Abstract: An anti-fold apparatus for high speed printers to prevent the folding or creasing of a printer ribbon riding over rollers. The rollers each have spiral angular serrations thereon, and are mounted in two pairs with each roller in a pair having one end abutting the end of the other, and each being mounted at an angle to the elongated center axis of the other, so that a printer ribbon rolling thereon is directed away from the abutting ends of each pair of rollers to prevent creasing therein. A linkage connects the two pairs of rollers at their abutting ends for shifting the angular position of each pair simultaneously between first slanted positions, when the ribbon is moving in one direction, and second slanted positions, when the ribbon is moving in the reverse direction. The linkage is actuated by solenoids, actuated by the reversing of the ribbon.

Abstract: A ribbon mask for a wire or stylus-type dot matrix print head is carried with the print head, positioned between the print ribbon and the printing surface, and has a forwardly-angled integral flange extending from along a portion of the top of the main body of the ribbon mask. The flange rigidifies the intersection where the main body of the mask meets the flange, so that curving the ribbon mask along its longitudinal axis forms a generally triangular, forwardly-biased face adjacent the printing surface. Centrally located within the face is a vertically-oriented oval opening through which pass the printing wires as they move toward and strike the ribbon against the printing surface to form dot characters.

Abstract: In order to avoid ribbon rollover in a high speed impact printer, a crown roller, having a crown offset from the roller's center, is used to guide the ribbon. The crown tends to center the ribbon about itself and the roller is dimensioned so that the distance from the crown to the end flange of the roller is sufficiently far that under all operating conditions the ribbon will remain separated from the flange and hence will avoid rollover. In particular the roller is positioned so that the print head will initially impact the advancing ribbon off center toward one edge of the ribbon. As printing continues, this repeated impacting will cause that edge of the ribbon to wear, the result being that the tension across the ribbon will decrease and the crown roller will constantly reposition the ribbon as if it were of an ever decreasing width.

Abstract: A frame-supported ribbon supply and take-up system for typewriters and teleprinters of the type having a carriage-transported printing device. The system incorporates an articulated ribbon-guiding structure connected between the ribbon supply and take-up assembly for guiding and supporting the ribbon along a path of substantially constant length regardless of carriage position. The articulated structure is also incorporated into an easily installable ribbon cartridge.