Ink ribbon cartridge

Abstract: A cartridge (10) for an ink ribbon (12) suitable for being removably fitted in a printer in order to print a line of print by means of the ribbon, comprising a shell (11) containing a ribbon store (13) and a pair of arms (21, 22) fulcrum-mounted on two opposite ends of the shell (11) and suitable for guiding the ribbon (12) on the outside of the shell. When the cartridge (10) is fitted in the printer, the two arms (21, 22) are rotated with respect to the shell (11) in order to guide the ribbon in a printing zone at a distance from the shell. Conversely, when the cartridge (10) is removed from the printer, the two arms (21, 22) may be withdrawn upon the sides of the shell (11), thereby reducing the overall dimensions of the cartridge (10).

Description: This invention relates to a print or typing cartridge, comprising a shell and an ink ribbon housed inside the shell to form a store of ink ribbon, wherein the cartridge is arranged to be removably fitted in a printer for the purpose of printing, or typing, a line of print by means of the ink ribbon. Background of the invention The known art comprises numerous examples of cartridges, usually intended to be used on a needle type printer, having the characteristics outlined above. In general, these known type cartridges are arranged to be stably disposed with their shell in a prearranged seat in the printer for feeding, when in use, the ink ribbon towards a printing zone of the printer, where the ribbon is subjected to the generally impact type action of a printhead of the same printer in order to print the line of print. The known cartridges are normally provided with one or more guides made as one piece with the shell and suitable for guiding the movement of the ribbon to and from the printing zone. In particular, these guides define a predetermined path for the ribbon intended to enable the latter to reach the printing zone when coming from the shell wherein the ribbon is stored, and then to leave the printing zone and return again to the shell, after the ribbon has been used for printing. These known cartridges are, however, inadequate for use in special printers having a structure that does not enable the shells of the cartridges to be fitted and secured in a seat sufficiently close to the printing zone, and in particular in printers where the ribbon is arranged to be fed inside the printing zone along a plane that is angularly and spatially very different from the feeding plane of the ribbon inside the shell, when the latter is fitted in the above-mentioned prearranged seat in the printer. Document US-A-4 486 107 discloses a print cartridge comprising a case, a ribbon supply roll and a ribbon take-up roll which are coaxially accommodated in the case, and two articulated ribbon guides which are mounted on pivot blocks arranged at two opposite sides of the case, wherein each of the articulated ribbon guide is composed by a primery arm and by a secondary arm. When this cartridge is mounted on a printer, the two articulated ribbon guides are arranged rotated at a right angle with respect to the plane of the case for guiding respectively towards a printing zone the ribbon out going from the case, and for guiding the same ribbon, after it has been used for printing, back to the case. Also this cartridge appears as not being exempt from drawbacks. In particular the ribbon, while advancing parallelly to the plane of the case, is subject to a twist of ninety degree which is concentrated along a reduced portion of the ribbon advancement path. In fact, as a consequence of this twist concentration, the control of the ribbon tension appears rather critical and accordingly ribbon slackening might raise. Also other documents, as US-A-4 623 274 and US-A-4 437 778, disclose a print cartridge having a case and one or more external arms, connected to the case, which can be arranged aligned with the case, when the cartridge in not fitted on a printer, in order to reduce the overall cartridge dimensions, and which are arranged totaled with respect to the case for guiding a ribbon towards and from a print zone, when the same cartridge in fitted on a printer. Summary of the invention The object of this invention is accordingly that of producing an ink ribbon cartridge suitable for being fitted in a printer having a relative printing zone at a considerable distance from the seat prearranged in the printer for housing the shell of the cartridge, and comprising in particular a ribbon feeding plane inside the printing zone that is very different from the plane defined by the seat, and also of producing a cartridge that is of compact dimensions and easily manipulated by its user. Another object of this invention is that of producing an ink ribbon cartridge of the above type in which the ribbon is guided and its tension is controlled in a more efficient way, with respect to the solutions of the prior art, while the ribbon advances along the two different planes respectively defined by the seat and adjacent to the print zone. This object is achieved by the print cartridge having the characteristics defined in the main claim. Brief description of the drawings A clearer understanding of these and other characteristics of the invention will be gained from the following description, provided purely by way of an illustrative, non-restrictive example, with reference to the accompanying drawings, where: Fig. 1 is a partial plan view, with a number of parts removed and shown in section, of a print cartridge according to this invention, when removed from a printer; Fig. 2 is a front view, in partial section, of the cartridge of Fig. 1, when fitted in a printer; and Fig. 3 is a side view of the cartridge of Fig. 2. Description of a preferred embodiment of the invention With reference to Fig. 1 a cartridge according to this invention and containing a ribbon 12 impregnated with ink is generically indicated with the numeral 10. When in use, the cartridge 10 is arranged to be fitted in a printer, not depicted in the drawings, provided with a printhead, for the purpose of printing, by way of the action exerted on the ribbon 12 by the printhead, a line of print on a printing medium, such as for instance a sheet of paper, in correspondence with a printing zone of the printer . More specifically, the cartridge 10 comprises a hollow, flat shaped shell 11, housing the ribbon 12 inside and accordingly forming a ribbon store 13, and additionally arranged to be placed and fixed in an appropriate, prearranged seat in the printer; and also a feeding device 14 of the ribbon 12 comprising a pair of gearwheels 16 disposed at the entrance of the ribbon 12 in the store 13. The two gearwheels 16 are urged one against the other so as to mesh together, with the ribbon 12 in between, by a spring 15 acting on a mobile support 30, upon which one of the gearwheels 16 is rotatingly fitted. Further, the two gearwheels 16 are suitable for being rotated in the direction of the arrow 17 by a motor shaft of the printer in order to push the ribbon into the store 13, so that the ribbon is disposed therein forming a plurality of turns, and for feeding the ribbon 12 according to the direction indicated by the arrow 18 (Fig. 2). The ink ribbon 12 is, for example, of the endless type, namely it is formed by a closed loop of ribbon, and is additionally liable to perform a semi-rotation about itself, as is well-known in the sector art, in the area of a twisting zone 19, so as to present its two faces alternatively to the printing medium, and accordingly uniformly distribute ribbon wear and ink consumption between the two faces of the ribbon 12 itself. The cartridge 10 also comprises a guide body 20, slidingly coupled with a portion of the ribbon 12 extending outside the shell 11, and arranged to be fitted on a movable carriage of the printer, so that when the carriage moves back and forward parallel to the line of print, the guide body 20 also moves integrally with the carriage back and forward in the directions indicated by the arrows 28 in order to guide the ribbon 12 immediately facing the line of print, as it is printed. Inside the shell 11 the ribbon 12 is appropriately guided, for example by posts, so as to follow a predetermined feeding path both downstream of the store 13, and also upstream of the latter, and so as to reach again the store 13, after it has been used for printing. The cartridge 10 is also provided with means for constantly maintaining the ribbon 12 taut for correct use thereof during printing, comprising for example a leaf spring 25 acting directly on the ribbon 12 to exert a sliding friction on the latter as it is fed due to the rotation of the gearwheels 16. According to the main characteristic of the invention, the cartridge 10 is provided with two arms or guiding elements, 21 and 22, having an elongated shape and fulcrum-mounted at one end on the sides of the shell 11 to guide the ink ribbon 12, while it is being fed outside the shell 11. More particularly, the arm 21 is arranged to guide the ribbon 12 coming from the store 13 towards the printing zone, and has a pin 23 pivotingly fitted in a seat made in a first side of the shell. On the other hand, the arm 22 is arranged to guide the ribbon 12 coming away from the printing zone towards the store 13, and has a pin 24 rotating in a seat made in a second side, opposite the first side, of the shell 11. Either arm 21 and 22 is provided, at the end opposite that fulcrum-mounted on the shell 11, with a slot 31 through which the ribbon 12 extends for sliding during printing. Further, in order to avoid, during manipulation of the cartridge 10, the two arms 21 and 22 becoming detached from the shell 11, the latter is provided with tabs 26 that hold the pins 23 and 24 in their respective seats made in the sides of the shell 11. As shown in Figs. 2 and 3, the two arms 21 and 22 are suitable for rotating with respect to the shell 11 according to the directions indicated by the arrow 32 to assume, when the cartridge is not fitted in the printer, an idle position, represented by a dot and dash line, wherein the two arms 21 and 22 are withdrawn upon the shell 11, i.e. are arranged along the sides of the latter; and to assume, when the cartridge 11 is fitted in the printer, a work position, represented by an unbroken line, wherein the two arms 21 and 22 are rotated with respect to the shell 11, so as to distance themselves from the latter with their end opposite the end which is fulcrum-mounted. Accordingly, as will be obvious, the cartridge 10, once fitted in the printer, allows guiding of the ribbon 12 from the shell 11 to the printing zone and then from the latter back to the shell 11, despite the fact that the ribbon 12 is fed in the area of the printing zone along a plane that is at an angle to that along which the same ribbon 12 is fed inside the shell 11. It will be equally obvious that the cartridge 10 is compact and without any protruding parts when it is not fitted in the printer, so that the part may be packaged for shipping in a simply shaped, small-size box. When in use, the cartridge 10 is fitted in the printer by setting and blocking the shell 11 in the seat expressly made in the printer, and by rotating the two arms 21 and 22 with respect to the shell 11 so as to put them in the correct position for guiding the ribbon in the area of the printing zone. More particularly, the two arms 21 and 22 are blocked in their correct positions, with respect both to the shell 11 and to the printer frame, by way of blocking means not depicted in the drawings and already provided in the printer. The ribbon 12, when the cartridge 10 is fitted in the printer and in correspondence with the zone where the arms 21 and 22 are fulcrum-mounted on the shell 11, is subject to a change in its feeding plane. More specifically, the ribbon 12 inside the shell 11 is fed along a first feeding plane parallel to the shell 11 itself, whereas the ribbon 12, outside the shell 11, namely along the arms 21 and 22 and in the area of the printing zone, is fed along a second feeding plane, inclined with respect to the first one and defined by the rotated position of the arms 21 and 22 with respect to the shell 11. In order to ensure correct feeding of the ribbon 12 between the two feeding planes indicated above, and in particular so that the ribbon 12 does not become slack, the shell 11 is provided at its sides, adjacent to the zones where the two arms 21 and 22 are fulcrum-mounted, with two inclined edges 27 which link the trajectory of the ribbon 12 along the first feeding plane parallel to the shell 11 with the trajectory of the ribbon 12 along the second plane parallel to the rotated position of the arms 21 and 22. Subsequently, following use, the cartridge 10 may be removed from the printer by extracting the shell 11 from its seat and rotating the arms 21 and 22 so as to withdraw them with respect to the shell 11. In this way the cartridge 10, when not being used for printing, is of compact dimensions and may be stored away quite easily. It remains understood that changes and/or improvements may be made to the print cartridge described up to now, without departing from the scope of the scope of the appended claims.

Claims: Print cartridge (10) comprising a shell (11), and an ink ribbon (12) contained in said shell (11), said cartridge (10) being provided for being removably fitted in a printer for printing by means of said ink ribbon (12) a line of print, said print cartridge (10) further comprising at least one guiding element (21, 22) fulcrum-mounted at one end on a side of said shell (11) for guiding said ribbon (12) on the outside of said shell (11), said guiding element (21, 22) being suitable for assuming, when said cartridge (10) is fitted in said printer, a work position in which said guiding element (21, 22) is rotated at a distance from said shell (11) for guiding said ribbon (12) adjacent to said line of print, and for assuming, when said cartridge is not fitted in said printer, an idle position in which said guiding element (21, 22) is withdrawn upon said shell so as to reduce the overall dimensions of said cartridge, wherein, when said print cartridge (10) is fitted in said printer with said guiding element (21, 22) in said working position, said shell (11) defines a first feeding plane of said ribbon (12), and said guiding element (21, 22) defines a second feeding plane of said ribbon inclined with respect to said first feeding plane, characterized in that said shell (11) is provided at one side, adjacently to the zone where said guiding element (21, 22) is fulcrum-mounted, with at least one edge (27) which defines a guide for said ribbon (12) and which is inclined with respect to each of said feeding planes for linking the trajectory of the ribbon (12) along said first feeding plane, parallel to said shell (11), with the trajectory of the ribbon (12) along said second feeding plane, parallel to the rotated work position of said guiding element (21, 22), thereby enabling correct feeding of said ribbon (12) between said first and said second feeding plane. Cartridge according to claim 1, characterized in that it comprises two guiding elements (21, 22) fulcrum-mounted at one end on two opposite sides of said shell (11). Cartridge according to claim 1 or 2, characterized in that said guiding element (21, 22) is provided, at the end opposite that at which it is fulcrum-mounted on the shell (11), with a slot (31) arranged for guiding said ribbon (12).

Inventors: UGGETTI SERGIO, UGGETTI, SERGIO
Applicants: OLIVETTI TECNOST, OLIVETTI TECNOST S.P.A.
Application year: 1998
Main classification: B41J32
IPC codes: B41J32, B41J33, B41J35