US 3871507 A
A spoolless ribbon cartridge containing either an endless fabric ribbon or a roll of single-pass carbon ribbon and having projecting members which hold a portion of ribbon accessible for printing. The cartridge has built-in rotatable drive members for forcing used ribbon into a chamber of the cartridge where it is stored in random, multi-folded fashion. By using loosely-meshed gears as drive members, the ribbon does not stick to the drive members and may be precreased during entry into the chamber. Oscillating fingers strip the ribbon from the gears and help pack the ribbon in the chamber. The drive members are rotated under control of a ribbon lift mechanism, which positions the cartridge such that printing occurs alternately from the upper and lower halves of the ribbon. Such rotation may effect a half-character movement of the ribbon in each printing cycle or a full character movement of the ribbon in every other print cycle, depending on the design.
Description (OCR text may contain errors)
United States Patent Perry et a1. Mar. 18, 1975 [541 SPOOLLESS RIBBON CARTRIDGE WITH 3,758,012 9/1973 Bonner et a1. 197/151 UX LIFT AND FEED FEATURES COMBINED FOREIGN PATENTS OR APPLICATIONS  Inventors: Donald S. Perry, 858 Renetta Ct., 12,870 1913 United Kingdom 197/168 11 0s lA1toIDCa g y 29235 1913 United Kingdom 1. 197/168 0w er, ox reen, 13778; R'chard Shatmck Primary E.\'aminer-Ernest T. Wright, Jr. 3869 Hlghland R Hans Attorney, Agent, 0rFi/'/11Armand G. Guibert; Milton 2 :32:2 t g g bmh of M. Wolson; John A. Taylor  Filed: June 5, 1972  ABSTRACT 1 1 pp 259,766 A spoolless ribbon cartridge containing either an endless fabric ribbon or a roll of single-pass carbon ribbon 152 11.5. (:1 197/151, 197/158, 197/168 andhaving Projecting b which hold 91  int. Cl B4li 33/14 of nbbon accesslble for Prlmmg' The Camdge has  Field of Search 197/151 153 R 6 157 built-in rotatable drive members for forcing used rib- 197/158 bon into a chamber of the cartridge where it is stored in random, multi-folded fashion. By using loosely  References Cited meshed gears as drive members, the ribbon does not stick to the drive members and may be precreased UNITED STATES PATENTS during entry into the chamber. Oscillating fingers strip 225,203 3/1880 Abele 1797/l X the ribbon from the gears and help pack the ribbon i y f f at 643 22; the chamber. The drive members are rotated under 6 l n [97/168 control of a ribbon lift mechanism, which positions the 5 6/1913 X cartridge such that printing occurs alternately from (M936 Gmnghn 197/153 R the upper and lower halves of the ribbon. Such rot-11- 2,635,357 3/1954 K k 197/1 tion may eftect a half-character movement of the rib- 3,-181,551 12/1969 Steelman 242/7111 A X bon in each printing cycle or a full character move- 3.513.957 5/1970 Ricciardi et a1. 197/151 ment of the ribbon in every other print cycle, depend- 3.568.943 3/1971 Robak 242/711 X d 3.621968 11/1971 Kondur 197/151 mg on L 651g 3,726,381 4/1973 Murphy 197/151 X 12 Claims, 6 Drawing Figures 57 662 4 2 b 9 e1 e7 2 ee 15 L -i I (57 5 58b 55b\ .516 1 5c 1A 670 I l3b 3 g 1 Ba 11] x 6 e 40 66b 2 2O SPOOLLESS RIBBON CARTRIDGE WITH LIFT AND FEED FEATURES COMBINED BACKGROUND OF THE INVENTION This invention relates to a ribbon mechanism for an office machine, such as a typewriter, and more particularly, to a ribbon cartridge and a lift and feed mechanism therefor.
Ribbon cartridges are known (from US. Pat. Nos. 2,902,136, 3,008,561, 3,151,724, 3,260,344, and 3,356,202, for example), but these all have disadvantages. Most have a multiplicity of parts such as supply and take-up spools, and drive means for both. In most cases, cartridge insertion in the machine requires careful location and a steady hand to pass the ribbon between the forks of the usual ribbon vibrator, or worse, requires manual stripping of a portion of the ribbon for such purposes, thus involving messy contact between the ribbon and the operators hands. Furthermore, because of the varying level of the ribbon on the take-up spool, during the feed operation the load on the ribbon tends to increase to the point of breakage, again involving a handling of the ribbon with consequent soiling of the operators hands.
SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems by providing a ribbon cartridge which is very simple in structure because it obviates the need for supply and take-up spools and their interrelated drives; eliminates need for a separate, variably positionable ribbon support mechanism; and incorporates a ribbon feed which stores the ribbon in the cartridge in random folds and may precrease it for more compact storage. The cartridge may contain inked ribbon, carbon ribbon, or the like and is readily interchangeable with similar cartridges. Spool herein refers to a flanged ribbon bobbin. By providing interfitting pivot members on each cartridge and on asupport in the typewriter, an old cartridge can be lifted out of the support and a replacement cartridge dropped onto the latter with an easy, simple motion and pressed into position for printoperation controlled rocking of its supported ribbon to alternate upper and lower elevations as determined by a ribbon lift mechanism. Further, ribbon feed members are built into the cartridge and operated by a mechanism forming part of the ribbon lift mechanism. Oscillating fingers strip the ribbon from the ribbon feed members and help pack the ribbon in the cartridge.
Accordingly, it is an object of the invention to provide a spoolless prethreaded ribbon cartridge of simple structure, adaptable to use either an endless web fabric ribbon or a single-pass carbon ribbon.
It is another object of the invention to provide a lowcost, throw-away type of cartridge for such ribbons requiring little skill for insertion and removal.
It is still another object of the invention to provide a ribbon cartridge in which the ribbon lift and ribbon feed mechanisms are combined.
Another object of the invention is to provide a ribbon cartridge in which the ribbon will not become entangled in the ribbon feed members.
BRIEF DESCRIPTION OF THE DRAWING The objects, features, and advantages of the invention will be apparent from a subsequent description of preferred embodiments of the invention made with reference to illustrations in the accompanying drawing, in which:
FIG. 1 is a perspective view of a fabric ribbon cartridge according to a first embodiment of the invention, including a lift and feed mechanism;
FIG. 2a is an enlarged perspective view of the ribbon feed entrance of the cartridge of FIG. 1, showing the ribbon disposed between dual feed gears with oscillating packing fingers for moving the entered ribbon away from the feed gears, while FIG. 2b is a plan view of same including a feed ratchet, pawl and detent;
FIG. 3 is a perspective view of a carbon ribbon cartridge according to a second embodiment of the invention, again including a lift and feed mechanism;
FIG. 4 is an enlarged perspective view of the ribbon supply exit of the cartridges of FIG. I or FIG. 3, showing the integral ribbon guides within the cartridge housing; and FIG. 5 is an exploded perspective view of the feed gears and oscillating packing fingers of FIG. 2a.
DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to FIGS. 1 through 5, these show the ribbon supply and its lift and feed mechanism as particularly applied to a printing machine having a single multi-character print element 42 movable laterally over the surface of a record medium 14 supported on a laterally fixed platen 15, although the concept is equally applicable to typewriters having a laterally movable document carriage and multiple typebars. A fabric ribbon cartridge 1 in FIG. 1 is a first embodiment of the invention, and a carbon ribbon cartridge 61 in FIG. 3 is a second embodiment, each of the cartridges 1,61 being interchangeably insertable in a support bracket 3 rigidly mounted on a support (not shown) for the print element 42 (shown in dotted outline) of the example, or forming part of the typewriter frame if applied to a typewriter having multiple typebars supported in a fixed segment of the typewriter frame. Cartridges 1 and 61 are each pivotable about pivot studs 4,5 fixed to vertical side flanges 2b, 2a of support bracket 3. The studs 4,5 enter recesses or notches 9 (only one shown in FIG. 1) formed in the sidewall of each cartridge 1,61 for purposes of ready insertion and removal by a simple drop-in/lift-out technique and for locating the ribbon 8 or 66 with respect to the platen .15. A latch (not shown) may lock the cartridge 1 or 61 down.
Fabric ribbon cartridge 1 is in the form of a roughly U-shaped housing 1a enclosing a chamber 7. Sidewall 6 of cartridge 1 is of sufficient depth to permit chamber 7 to accommodate the vertically-oriented ribbon 8. Similarly, the base 10 of chamber 7 is of sufficient area to accept a predetermined length of fabric ribbon 8. Two projecting members 13a, 13b of cartridge 1 which form the arms of the U function as supports and guides for the active portion 8a of fabric ribbon 8. The spacing between projecting members 13a, 13b and their length is such as to accommodate the entry of print element 42 into printing position relative to the active ribbon portion 8a. In cartridge 1, fabric ribbon 8 is an endless web, supplied with and prethreaded in cartridge 1 so that during typing operation, ribbon 8 is pulled to the right (as shown by the arrow on portion 8a in FIG. 1) through an exit opening 56 of cartridge 1 to present successive fresh surfaces of ribbon 8 as the active ribbon portion between the multi-character single print element 42 and the usual record medium 14 supported on a platen 15, the ribbon movement resulting from rotation of feed rotors in the form of feed gears 11 and 12, described in detail subsequently. Gears 11,12 near an entrance opening 56a to chamber 7, stuff the recently used, now inactive portion 8b of ribbon 8 into chamber 7.
In addition to chamber 7, cartridge 1 contains within it fixed, integral exit guide pair members 45,46 and 47,48 (best seen in FIG. 4), oriented to insure smooth egress of ribbon 8 from cartridge 1 and to prevent previouslyentered sections of ribbon 8 from being prematurely forced out of chamber 7. Guide pair members 47,48 have a gap between them equivalent to the thickness of ribbon 8, which gap forms the exit opening 56 of cartridge 1. The inner guide pair members 45,46 are spaced slightly further apart than the outer guide pair members 47,48 so that the exiting portion of ribbon 8 is funneled from a multiple ribbon thickness at the entrance to guide members 45,46 to a single ribbon thickness at guide members 47,48 to insure proper egress.
As mentioned previously, after passage through exit opening 56 in the left projecting member 13b of cartridge 1, the active portion 8a of ribbon 8 passes between print element 42 and record medium 14 to the right projecting member 13a of cartridge 1, where it is subsequently picked up by the feed gears 11,12. Ribbon 8 may be guided in this traverse by means ofa pair of chutes 58a, b, a respective one of the pair forming part of sidewall 6 in the area of projecting members 13a, 13b. Chutes 580, b may be provided with flanges 59 for better control, if desired (see FIG. 2a). Ribbon feed-in gear 11 (see FIG. 2b), fixed on a vertical shaft 55a, has two spaced eccentrics 49 (for a purpose explained subsequently) and its teeth 17a mesh loosely with teeth 17b of gear 12, fixed on a parallel shaft 55b, and identical to gear 11 except that gear 12 has an extra two teeth 17b. The distance between the shafts 55a, 55b and the gear 11, 12 sizes are such that space 16 between gears 11,12 is approximately the thickness of ribbon 8 so as to insure proper feeding of ribbon 8 between gears 11,12 during the gear drive operation for re-entry of now inactive ribbon portion 8b into chamber '7. Fixed to shaft 55a is a drive ratchet 53, the teeth 50 of which cooperate with a feed pawl 38 to rotate feed gear 11 in the counterclockwise direction. Re entry of ribbon 8 into chamber 7 could be achieved with a pair of plain rollers (not shown), but ribbon 8 tends to stick to such rollers. The problem of sticking is solved by use of loosely-meshed gears 11,12 as drive members and, furthermore, precreasing of ribbon 8 by action of teeth 17a, 17b provides better packing of ribbon 8 within chamber 7, as explained subsequently.
Maintenance of proper tension on the active portion 8a of ribbon 8 during print operation is assured by a spring 57 (see FIG. 4 for best view) positioned near ribbon exit opening 56. Spring 57 has a formed end 60 adjacent feed-out guide chute 58b and is fastened to sidewall 6 by rivets 62, or the like, the length of end 60 being such that spring 57 is under stress when fastened to sidewall 6. If cartridge 1 is plastic, spring 57 may be integrally molded. Ribbon 8, being inserted between the formed end 60 and guide chute 58b, is therefore clamped between the two and subject to friction force exerted by spring 57. Ribbon 8 is thus held substantially taut since on the other side, feed gears 11,12 are locked against reverse rotation by interaction of a detent 63 and ratchet 53. The detent 63 can'be formed integral with a wall 6a of the projecting member 13a from a plastic.
To facilitate the above-mentioned packing and to prevent ribbon 8 crowding in the area near the outlet of gears 11,12, the pair of spaced eccentrics 49 (see FIG. 2a) are eccentric with respect to shaft 550 similar eccentrics 49 on gear 12 being likewise eccentric with respect to shaft 55b (note that the upper portion of gear 11 has been removed in FIG. 2a for better visibility of the members next described). A pair of fingers 51a, 51b are each mounted on eccentrics 49 by means of their arcuate clasp members 52. A sliding fit between clasp members 52 and eccentrics 49 thus tends to oscillate fingers 51a, 51b not only together and apart, but also back and forth as eccentrics 49 rotate with shafts 55a, 55b. Friction between clasp members 52 and eccentrics 49 and/or the pressure of the inactive ribbon portion 8b keeps ends 64 of fingers 51a, 51b in contact with the inside of sidewall 6 (not shown in FIG. 2a). In this fashion, as ribbon 8 is being creased and stuffed into chamber 7 during rotation of shaft 550, fingers 51a, 51b projecting inwardly into chamber 7 serve to strip ribbon 8 from gears 11,12 and oscillation of these fingers 51a, 51b pushes the creased ribbon 8 away from the area near gears 11,12. It will be understood, of course, that the oscillation may be omitted, if desired, in which case though not illustrated eccentrics 49 may be made noneccentric and fingers 51a, 51b are then fixed barriers which only assist in stripping ribbon 8 from gears 11,12.
In a second embodiment, shown in FIG. 3, a similar cartridge 61 having external dimensions identical to those of cartridge 1 is partitioned into two chambers 65a, 65b, the first chamber 65a being of sufficient area to accept the inactive portion 66b of a carbon ribbon 66 from a spoolless supply roll 67 which supplies the active portion 66a of the carbon ribbon 66. Roll 67, preloaded and confined in the second chamber 65b, has a flangeless bobbin 67a and is rotatable around a pin 69 located in a slot 68. The purpose of slot 68 is to enable the operator to judge theamount of ribbon 66 remaining on roll 67 so that its exhaustion will not catch the operator unawares. The construction of the remainder of carbon ribbon cartridge 61 is identical to that of fabric ribbon cartridge 1 except that there is no need for communication between chambers 65a and 65b, since carbon ribbon 66 is nonreusable and travels past print element 42 only once. Accordingly, when the nonreusable carbon ribbon 66 on supply roll 67 is exhausted, cartridge 61 is discarded.
The drive means for lifting ribbon 8 and for feeding fresh ribbon 8 to print element 42 will next be described. As this mechanism is identical for both fabric ribbon cartridge 1 and carbon ribbon cartridge 61, the description will be made only with respect to cartridge 1 and with reference to FIG. 1 alone. As seen therein, a lift bellcrank 18 is rockably supported on pivot stud 5, bellcrank 18 being in the form of an inverted V with arms 19,22. Arm 22 of bellcrank 18 has an ear 39 formed into its upper margin (as seen in FIG. 1), ear 39 being of such length as to project under and give support to cartridge 1. Location of a similar ear 40 on the upper margin of arm 19 allows the previously mentioned drop-in mode of insertion of cartridges 1 and 61, abutment of ear 40 with a second point under cartridge 1 providing the necessary alignment of notches 9 and pivot studs 4,5. The other arm 22 of bellcrank 18 terminates in pivot disc 23 which is retained within a yoke 24 of an upward extension 25 ofa bail 26. Bail 26 is pivotally supported on a stud 27 mounted on the support (not shown) for print element 42 (or on a frame member in the case of a conventional typewriter).
A lower extension 28 of bail 26 has a cam roller 29 rotatably mounted at the free end of extension 28 (Le, remote from stud 27). Bail 26 is adapted to rock back and forth because cam roller 29 lies within the symmetrical, approximately elliptical path defined by a camming slot 38 cut into a face 31 of a gear 32. Gear 32 also mounted on the support for print element 42 is in mesh with a like-mounted actuating gear 33 driven by a power roll shaft 34. An axial slot 70 on the surface of shaft 34 and a mating tooth 71 on gear 33 provide lateral slidability of gear 33 on shaft 34 (only in the case of the single print element typewriter of the example, gear 33 being laterally fixed in the case of a conventional typewriter).
At its free end (i.e., remote from pivot 5), arm 19 supports a pivot upon which is rockably mounted a feed bellcrank 21, which has two arms 35,36. Arm 35, sinuous in contour, has a slot 37 which controls movement of feed bellcrank 21 during the latters operation by reason of cooperation with a projecting stud 41 fixed to flange 2a of support bracket 3. Arm 36 of feed bellcrank 21 terminates in pawl 38, previously mentioned.
The lift actions of bellcrank 18 which result in a corresponding ribbon drive action through bellcrank 21 will next be described (still using cartridge 1 for reference). Considering now a complete operational cycle, whenever a key button (not shown) corresponding to a selected character is depressed, a power roll singleturn clutch (again not shown, but known) is engaged with the result that power roll shaft 34 and gear 33 engagingly, but laterally movably mounted upon shaft 34 are driven one revolution clockwise (a direction chosen merely for purposes of this description because such direction is arbitrary inview of symmetry of camming slot 30). Gear 32 having a diameter exactly twice the diameter of gear 33, each clockwise revolution (one cycle) of gear 33 therefore rotates gear 32 counterclockwise one-half revolution, The first quarterrevolution, say, of gear 32 (a half-cycle of gear 33) displaces cam roller 29 from its dwell 54a to a first cam lobe 43, this lobe 43 being the higher one of two lobes 43,44 in camming slot 30, both these lobes 43,44 including a constant radius portion at their peaks so that ribbon 8 may be held still during printing, in known fashion. Consequently, as bail 26 pivots clockwise about stud 27, lift bellcrank l8 pivots counterclockwise about stud 5, and cartridge 1 is urged counterclockwise by cooperation with ears 39,40 on arms 22,19, thereby bringing ribbon portion 8a to its uppermost position (corresponding to the peak of lobe 43), such that the character font of print element 42 selected by the key button depressed will contact the lower half of the active ribbon portion 8a and record the selected character on record medium 14, as print element 42 proceeds through a print cycle in known fashion.
Simultaneously, ribbon feed bellcrank 21 being pivotally mounted about pivot 20 fixed to arm 19 of bellcrank 18, and having its pivoting motion further controlled by cooperation between camming slot 37 in its arm 35 and stud 41 fixed to bracket 3, also pivots counterclockwise, preparatory to a feeding engagement between pawl 38 and the next tooth 50a of ratchet 53. Camming slot 37 is shaped such as to aid in limiting the travel of pawl 38 to an amount sufficient to pick up just the one tooth 50a. In FIG. 2b, it will be noted that during counterclockwise rotation of bellcrank 21, the furthest retracted position of pawl 38 (shown by a dotted outline) is shifted to the left that is, behind the next tooth 50a of ratchet 53. This is accomplished through use ofa resilient material (such as an acetal plastic) for bellcrank 21 or by providing pivot 20 with a head portion and urging bellcrank 21 leftward in known fashion by means of Belleville springs inserted between the bellcrank 21 and the head of pivot 20.
In the second quarter-revolution of gear 32, say, the reverse sequence occurs in that cam roller 29 traverses from lobe 43 to cam dwell 54!) equal in height to cam dwell 54a, resulting in return of ribbon cartridge 1 to its normal position in which the printed line on record medium 14 is visible. During this second half of the cycle, ribbon feed bellcrank 21 now rotates clockwise about pivot 20 causing pawl 38 to engage tooth 50a of ratchet 53, pawl 38 having fallen behind tooth 50a during the first half of the cycle, it will be recalled. Thus, feed gear 11 is rotated counterclockwise, in mesh with driven feed gear 12.
Because the cartridge 1 has ribbon 8 prethreaded between feed gears 11 and 12, then during rotation of these gears 11,12, meshing ones of their respective gear teeth 17a, 17b contact ribbon 8, the different number of teeth 17a, 17b reducing the tendency of ribbon 8 to stick to gears 11,12. Note that if the gears 11,12 are identical, the teeth 17a, 17b then induce therein an equally spaced, vertical creasing which facilitates entry into chamber 7 in a more condensed fashion, resulting in a greater volume of ribbon 8 being storable in a cartridge 1 of given size. Rotation of these gears 11,12 also moves ribbon 8 across the span between projecting members 13a, 13b to place fresh ribbon 8 in front of print element 42, as previously described.
. On the followingselection of a key button, another clockwise revolution (one cycle) of gear 33 causes the second half-revolution of gear 32. In this second halfrevolution, cam roller 29 starts at dwell 54b; progresses to the highest portion of lobe 44, which has a rise smaller than that of lobe 43; and then returns to dwell 54a, the original starting point in the foregoing description. The actions during this second cycle are similar to those described for the first cycle, except that the smaller rise of lobe 44 moves lift bellcrank 18 through a smaller arc and thus rocks cartridge 1 a correspondingly small amount so that the selected character font of print element 42 now contacts the upper portion of ribbon 8 during the print action by element 42. The alternating upper and lower impressions on the ribbon 8 result in a more economical ribbon 8 usage. It should also be remarked that the design of the drive mechanism may be made such that a ribbon 8 motion of half a character space occurs in each cycle (as would be illustrated by staggered arrangements of the letters I-I marked on the ribbon 8 of FIG. 2a), or such that a ribbon 8 motion of a full character space occurs only after two impressions have been made on record medium 14, that is, only in every other cycle of gear 33 (not illustrated). The latter type of feed motion could be achieved, for instance, by choosing dimensions of the respective bellcranks 21,18 and the shape of slot 37 such that the second movement of bellcrank 18 would be insufficient to bring pawl 38 behind tooth 50a.
Between impression cycles, the power roll clutch is disengaged, of course, rendering power roll shaft 34 and lift and feed bellcranks 18,21 stationary until another character imprint is desired, at which time the abovedescribed operational sequence is repeated upon depression of a further keybutton.
The above description discloses a novel spoolless ribbon cartridge 1 or 61 and a combined ribbon lift and feed mechanism therefor, adaptable to business machines, comprising a cartridge 1 or 61 storing a supply of endless fabric ribbon 8 or a roll of carbon ribbon 66, respectively, and having built-in projecting members 13a, 13b over which the ribbon 8 or 66 passes to builtin ribbon feed gears 11,12 which crease the ribbon 8 or 66 while returning it to the cartridge 1 or 61 for storage therein in folded fashion, and which cooperate with a combined ribbon lift and ribbon feed drive mechanism l8,2l,26,29,30 on the machine, that mechanism being operated by the power roll shaft 34.
In light of the above-described embodiments, it will be evident to those skilled in the art that the present invention is susceptible of other modifications, substitutions, etc. and such are intended to be within the scope of the invention, it being defined only by the appended claims.
1. A spoolless ribbon cartridge for printing machines with at least one print element, comprising a. a housing having a first chamber with an entrance opening and a second chamber with an exit openb. a roll of carbon ribbon preloaded in said second chamber, said carbon ribbon having an active portion and an inactive portion and said inactive portion being storable in said first chamber,
0. a pair of projecting members associated with said housing and operable to support said active portion of said carbon ribbon in a spanning relationship with respect to said projecting members and external to said first and second chambers in a position accessible for cooperation between said print element and said carbon ribbon, and
d. means for feeding said carbon ribbon mounted in said housing proximate said entrance opening and in direct-contact driving relationship with said carbon ribbon whereby said carbon ribbon may be drawn through said exit opening, over said projecting members and into said entrance opening for forced, random storage of said inactive portion in said first chamber.
2. The spoolless ribbon cartridge of claim 1, in which said feeding means includes a pair of feed gears loosely meshed in the absence of said carbon ribbon and snugly meshed when said carbon ribbon is threaded between said feed gears.
3. The spoolless ribbon cartridge of claim 2, in which said feed gears have different numbers of teeth to help machine, the cartridge having a housing with a chamber for the ribbon and an entrance opening for the ribbon, and two feed rotors journaled in the housing near the entrance opening for feeding the ribbon between the feed rotors, wherein the improvement comprises:
a. eccentrics on the feed rotors and b. fingers mating with the eccentrics for oscillation by the eccentrics to strip the ribbon from the feed rotors and push the ribbon away from the feed rotors to help pack the ribbon in the chamber.
5. The cartridge of claim 4, in which the cartridge has sidewalls, and the fingers have clasp members that mate with the eccentrics and free ends that oscillate along the sidewalls when the fingers are oscillated by the eccentrics.
6. The cartridge of claim 5, in which the feed rotors are feed gears with different numbers of teeth to help prevent the ribbon from sticking to the feed gears.
7. An improved cartridge for a ribbon for a printing machine having a print element, means for pivotally mounting the cartridge, and means for oscillating the cartridge on the pivotal mounting means, the cartridge having a housing containing a chamber for the ribbon and two projecting members on the housing with free ends and openings in the free ends for the ribbon to span the projecting members to receive impacts of the print element, wherein the improvement comprises:
a. two feed rotors journaled in one of the projecting members for feeding the ribbon between the feed rotors and b. a ratchet on one of the feed rotors for interaction with the cartridge oscillating means to rotate the feed rotors and feed the ribbon during oscillation of the cartridge.
8. The cartridge of claim 7, further comprising:
c. a detent that engages the ratchet so that the ratchet can rotate in only one direction.
9. The cartridge of claim 8, in which the projecting member in which the feed rotors are journaled has a wall composed of a plastic and the detent is formed in tegral with the wall.
10. The cartridge of claim 7, further comprising:
c. eccentrics on the feed rotors and d. fingers mating with the eccentrics for oscillation by the eccentrics to strip the ribbon from the feed rotors and push the ribbon away from the feed rotors to help pack the ribbon in the chamber.
11. The cartridge of claim 10, in which the cartridge has sidewalls, and the fingers have clasp members that mate with the eccentrics and free ends that oscillate along the sidewalls when the fingers are oscillated by the eccentrics.
12. The cartridge of claim 11, in which the feed rotors are feed gears with different numbers of teeth to help prevent the ribbon from sticking to the feed gears.