GB1585979A - Typewriter ribbon feed and lift mechanism - Google Patents

Abstract

The device for transporting an ink-ribbon (6) and a correction-ribbon (7) for a type element typewriter has a cartridge holder (3) which is pivoted together with the ink-ribbon and correction-ribbon cartridge (4, 5) when the latter is inclined in order to present a part of the ink-ribbon (6) or of the correction-ribbon (7) at the printing point. The transporting and lifting of the ink-ribbon for printing are carried out by means of a cam (22) on which there are arranged several groups of elevations. The correction-ribbon (7) is driven by means of a second cam (35) which is actuated only when the machine is working in correction operation. The correction operation is controlled by pressing down the rear side of the cartridges (4, 5), their front part being raised and the correction-ribbon (7) being moved into its working position. <IMAGE>

Description

(54) TYPEWRITER RIBBON FEED AND LIFT MECHANISM (71) We, INTERNATIONAL BUSI NESS MACHINES CORPORATION, a Corporation organized and existing under the laws of the State of New York in the United States of America, of Armonk, New York 10504, United States of America do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to typewriter ribbon feed and lift mechanisms for cartridges having two ribbons therein.

Correction typewriters and mechanisms for feeding ribbons and correction tapes on typewriters have become relatively well known in the recent past. An example of such a typewriter is the IBM Correcting SELECTRIC typewriter (IBM and SELEC TRIC are registered trade marks) which embodies a ribbon feed mechanism and ribbon cartridge substantially similar to that disclosed in the specifications of our Patent Nos. 1183172, 1183173 and 1221384. The correction tape and feed is similar to that disclosed in the specification of our Patent no. 1316534.

With the increased use of cartridges. due to their ease of inserting and threading the ribbon and the cleanliness associated with handling a plastic cartridge as opposed to handling a printing ribbon and adhesive tape, it has become desirable to implement a system wherebv the printing ribbon and the correction tape are both contained within cartridges. An example of a ribbon feed and cartridge design for accomplishing this is disclosed in the specification of our co-pending application for Letters Patent No. 16573/78 (Serial No. 1585245).

Patent specification No. 1221384 discloses a ribbon spool on a fixed axis which is peripherally driven by spiked driver. The apparatus to insert the spiked driver into the cartridge is relatively complex. Added complications arise if the driving mechanism is required to transport a second, separate ribbon.

It is desirable for the respective take-up spools of the ribbon and correction tape to be rotatable about fixed axes in the cartridge to minimize the manufacturing cost of the consumable cartridge.

According to the invention. ribbon feed and lift mechanism comprises a rotatable print shaft, a holder for the cartridge mounted for oscillation. separate feed drives for the ribbons, a first cam driven by the print shaft, a first cam follower means interconnecting the first cam and one of the ribbon feed drives to effect ribbon feed upon the rotation of the first cam, a second cam follower interconnecting the first cam and the holder to effect oscillation of the holder, a second cam driven by the print shaft, and a third cam follower connected to the other ribbon feed and mounted for normal disengagement from the second cam and selectively movable into engagement with the second cam to effect ribbon feed upon rotation of the print shaft.

The scope of the invention is defined by the appended claims; and how it can be carried into effect is hereinafter described with reference to the accompanying drawings. in which: Figure 1 illustrates a typewriter having a fixed print mechanism and ribbon feed and a movable paper carriage; Figure 2 is a plan view of a ribbon feed and lift mechanism according to the invention; Figures 3, 4A, 4B, 5, 6, 7. and 8 are views of parts of the mechanism of Figure 2.

Figure 9 is a perspective view of a second embodiment of the ribbon feed and lift mechanism according to the invention; Figure 10 is a plan view from the top of a double cam forming part of the mechanism of Figure 2; and Figures 11 and 12 are cam rise diagrams fore cams Figure 10.

A ribbon feed and lift mechanism (Figure 2) is mounted to pivot on a frame 10 of a single element typewriter 8 (Figure 1) and to support ribbon and correction tape cartridges 16 and 18 thereon. Each cartridge is fabricated to have an end opening (Figure 9) close to a take-up spool, to permit a spring biased arm carrying a tape feed wheel to enter into the cartridge and engage the periphery of the tape or ribbon on the take-up spool. The drive wheels are ratchetdriven in response to cam follower movement due to rotation of a cam. Rises of lobes on the cam control the amount of movement or displacement of the cam follower and hence the ratchet drive thereby controlling the increment of feed.The same rises on the cam are utilized to control the rocking of the ribbon cartridge support to effect raising the ribbon to the print line and holding it in one of two different positions for printing. A normally disengaged cam follower and linkage is connected to the correction tape feed and mounted so that the follower will engage the correction tape feed cam upon the rocking of the cartridge support to its extreme displaced position thereby effecting the maximum rise of the tape cartridge and correction tape cartridge portions which span the type element to present the respective ribbon and tape to the print point.The ratchet feed utilized for the feeding of the ribbon is constrained so that the ratchet remains in position when the driving pawl is withdrawn and then allows the driving pawl to re-engage the ratachet drive surface to complete the drive for a complete feed increment upon the complete or full throw of the cam follower and connecting linkage.

The typewriter 8 has a movable paper platen and a fixed print carrier. but the invention is applicable to a typewriter with a fixed platen and movable print carrier. The frame 10 of the tvpewriter carries two pivot pins 12 on which a cartridge holder 14 is supported.

Two superposed. separably attached car tridges 16 and 18 can be mounted on the holder 14. Each cartridge has a ribbon supply spool and a ribbon take-up spool (not shown). Cartridge 16 contains print ribbon 20 and the cartridge 18 contains correction tape 22. Each of the cartridge 16 and 18 has a pair of extension arms with a ribbon entrance and a ribbon exit. respec tively. so that a span ribbon is exposed externally of the cartridge. the spans being above and below each other. The spans of ribbon 20 and tape 22 are located between a printhead 9 of the typewriter and the platen 11 with the cartridges on the holder 14. The cartridge holder 14 also supports components of the ribbon drive and ribbon feed mechanism.

The holder 14 has an extension 24 on which is mounted a pivot rod 26. Pivotally supported on the pivot rod 26 are two independently swingable arms 28 and 30.

Arm 28 carries on its end a rotatable feed wheel 32 on an axle pin 40 and a ratchet feed mechanism for the wheel 32. The wheel 32 on the arm 28 can enter an end opening in the cartridge 16 to engage.the ribbon on the take-up spool. The feed wheel 32 has apertures 34 (Figure 4B) formed in the face thereof for engagement by a pawl member 36, formed as a small tab on the end of a lever 38 mounted on the axle pin 40. A spring 27 (Figure 3) connects the lever 38 and the arm 28.

A push-pull link 42 is connected between the lever 38 and a cam follower 44 (Figures 5 and 6) pivotally mounted on a pivot 46 in the frame 10.

The cam follower 44 has an upturned end 43 to engage the peripheral surface of a feed/lift cam 48 mounted on a shaft rotatable in the frame 10. The cam is rotated from a cyclically operable driver shaft 52 of the typewriter by a gear pair 50 which comprises a gear 53 on the cam shaft and a gear 51 on the shaft 52.

Arm 30 carries a rotatable feed wheel 60 and a ratchet feed mechanism, similar to those on the arm 28. The wheel 60 can enter an end opening in the cartridge 18 to engage on the take-up spool within the chamber of the cartridge. The wheel 60 is mounted on arm 30, on an axle pin 64 (Figure 8) and can be driven in one direction by a pawl 63 on the end of a lever 62 on the axle pin 64. A spring 31 (Figure 3) is connected between the lever 62 and the arm 30. Between the lever 62 and a cam follower 68 (Figure 5) is connected a push-pull link 66. The cam follower 68 is pivotally mounted on a pivot pin 69 in the holder 14 and has an upturned end 70 (Figure 7) which is engageable with the peripheral surface of a cam 72 mounted on the same shaft as the cam 48 to rotate therewith. As the cam follower 68 is mounted on the holder 14 it is movable about the axis of the pivot pins 12. When hen the holder 14 is pivoted sufficiently to depress the rear of the cartridges 16 and 18 to present the correction tape 22 to the print point. the upturned end 70 of the cam follower 68 engages the surface of the cam 72. Upon the engagement of correction tape cam follower 68 with the feed cam 72. the follower 68 will oscillate and provide oscilla torv motion to the feed arm 62 for rotation of the correction tape feed wheel 60 upon each rotation of the operational shaft 52 so long as holder 14 is held in the position corresponding to the correction tape being presented to the print point.With the correction tape feed cam 72 engaged by the correction tape feed follower 68, any otherwise normal printing opertion will result in the impacting of the printhead 9 of the typewriter 8 onto the correction tape 22 and forcing it against the page at the print point.

Inasmuch as the operational shaft 52 will rotate, as with any other printing operation, the tab 70 on the correction tape follower 68 engaged by the cam surface of cam 72, is caused to translate or oscillate, effecting the feeding of the correction tape within the correction tape cartridge 18.

In order to insert cartridges 16 and 18 on the holder 14, it is necessary to withdrawn the arms 28 and 30 carrying the feed wheels 32 and 60. For this purpose pull links 100 and 102 (Figure 3) are connected, respectively to the axle pins 40 and 64 on the arms 28 and 30. The pull links 100 and 102 extend to one end of the holder 14 and have apertures 104 and 106 (Figure 2) respectively, which are engaged bv bifurcated crank arm 108 mounted on an axle 110 on the frame 10. A link 112 is connected between the crank arm 108 and a bifurcated pivoted control lever 114. which extends outside the cover of the typewriter for manual operation.

Operation of the lever 114 pushes the link 112 to the left (Figure 2), pivoting the crank arm 108. This pulls the links 100 and 102 to the left (Figure 2) and the arms 28 and 30 are pivoted clockwise about the pivot pin 26 against the action of springs 25 and 29 (Figure 3), respectively. to positions clear of the cartridge position. After insertion of the cartridges, the lever 114 is returned to its initial position and the arms 28 and 30 are pivoted counterclockwise (Figure 2) by their respective springs 25 and 29 (Figure 3). to enter the end openings and engage the ribbon and tape on the take-up spools of the cartridges 16 and 18.

The cartridge holder 14 is biased about the pivot pins 12 (Figure 8) by a spring 15.

The biasing is downwards at the front and upwards at the rear. so that the span of ribbon 20 and tape 22 is clear of the print position of the print element 9 (Figure 1).

The descent of the front of the holder is limited by engagement of a fixed cam follower 92 (Figures 7 and 8) on the holder 14 with the peripheral surface of the cam 48.

As will be seen from Figure 10. the cam 48 has four lobes with intervening low dwells 45. Two lobes 49 are high rise lobes and two lobes 47 are intermediate rise lobes. During one revolution of the shaft 52 (Figure 6) (that is one print. space. or correct operation) the cam 48 rotates through 90". Engagement of the cam follower 92 with a low dwell 45 on the cam 48 allows the holder 14 to be depressed to the full extent. As the cam 48 rotates and the cam follower rises to an intermediate lobe 47, the holder 14 is pivoted to an intermediate position to present the upper portion of the span of tape 20 to the print position of the print element 9.

As the cam follower 92 passes off the lobe 47, the holder returns to its depressed position, revealing the character printed on the paper above the tape 20. Upon a further rotation of the shaft 52. the cam follower 92 rides up the next lobe 49. and the holder 14 is pivoted to a high position to present the lower portion of the span of tape 20 to the print element 9.

The rise of each lobe 49 from the low dwell 45 is twice as much as the rise of each lobe 47, but it will be appreciated that this may be varied.

The upturned end 43 (Figue 6) of the cam follower 44 also engages the cam 48. During one cycle of rotation of shaft 52, the cam follower 44 is pivoted about the pin 46 in both directions and by the link 42 effects a similar oscillation of the lever 38 (Figure 4B). This oscillation causes unidirectional rotation of the feedwheel 32 to rotate the take-up spool of the cartridge 16 by engagement with the ribbon thereon and thus to draw ribbon from the supply spool and present a fresh portion of the ribbon in the span offered to the print element.

The upturned end 43 may engage the cam 48 at a position such that ribbon feed occurs before or after printing. but a small amount of movement of the ribbon during printing does not adverselv affect the quality because the printing impact is very quick.

To effect correction. the platen is backspaced to present the incorrect character in the print position and the holder 14 pivoted downwardlv at the rear. either manually. or by operation of a correction or erase key.

The holder is then latched in this highest position. presenting the span of correction tape to the print element. The holder 14 has a depending limb 120 (Figure 8). One side of the limb 120 is engaged by a latch member 122 pivoted on a pin 126 on the frame 10. A spring 124 urges the member 122 against the side of the limb 120. In the highest. correction position of the holder.

the limb 120 is moved into a notch in the latch member 122 and is held against return bv the latch member 122 under the influence of the spring 124. The kev corresponding to the character to be erased or deleted is depressed and the print element strikes the correction tape 22 against the printed character to remove it bv adhesion or to cover it up. During this time. the shaft 52 rotates and a cam 132 engages a cam follower 130 on an extension 128 of the latch member 122. This pivots the latch member 122 and releases the limb 120 for restoration of the holder 14 to its lowest position. The holder is then ready for the next print cycle operation.

With the holder in 14 in the lowest position (Figure 7) the upturned end 70 of the cam follower 68 is clear of the cam 72. In the intermediate and high (print) positions of the holder 14, the same applies. In the highest, correction position of the holder 14, the upturned end 70 of the cam follower 68 engages the cam 72 (chain dotted lines in Figure 7). The cam 72 (Figure 10) has four rises and steep descents. During rotation of the shaft 52 for a correction stroke, the end 70 rides up a rise of the cam 72 from its rest position (Figure 10), pivoting the cam follower 68 (Figure 5). This pulls the link 66 which pivots the lever 62 (Figure 3) about the pin 64.This causes unidirectional rotation of the feedwheel 60 to rotate the take-up spool of the cartridge 18 by engagement with the tape thereon and thus to draw tape from the supply spool and present a fresh portion of the tape in the span offered to the print element.

The rises on the cam 72 may be such that rotation of the feedwheel is completed or almost completed at the time of print element operation. or may occur after such operation is complete.

The correction tape cam profile is illustrated in Figure 12. and results in a single character increment of the feed for each 90" rotation.

The ribbon lift/feed cam profile is illustrated in Figure 11. and results in different increments of ribbon feed in alternate 90" rotations. The rise of the upturned end 43 of the cam follower 44 on the cam 48 from the low dwell 45 to the high lobe 49 results in one complete ribbon feed increment. The relationship between the low dwell 45 and the rise on lobe 47 is not critical. because the smaller rise will provide a partial increment of feed due to the engagement of the pawl 36 (Figure 4B) on lever 38 with an aperture 34 in feed wheel 32. The partial increment of feed accomplished during the low rise results in the pawl 36 (Figure 4B) reengaging the same aperture 34 on the next successive high lobe 49 and not initiating feed until such time as the rise of the lobe 49 has reached the equivalent of the preceding low intermediate lobe 47.At that point. the arm 28 will have been displaced sufficiently far to engage the pawl 36 with the edge of the aperture 34 and again to feed the feed wheel 32 the remainder of the feed increment.

Operatioll To insert the cartridge 16 and 18 into the ribbon feed mechanism. the pull lever 114 (Figure 2) is pivoted to retract arms 28 and 30. The cartridges 16 and 18 are then placed onto the holder 14. After the placement of the cartridges, the control lever 114 is returned to its disengaged position thus allowing arms 28 and 30 to enter the apertures formed in the end of the cartridges 16 and 18 and allow the feed wheel on each of the arms 28 and 30 to engage the periphery of the take-up spool or ribbon disc or tape disc, if ribbon or tape is already partially wound upon their respective spools. At this point the loading sequence is completed and the typewriter 8 is otherwise ready for operation. As each character is typed, the operational shaft 52 is rotated one complete revolution by a drive mechanism which cyclically operates this shaft.As the shaft operates, gear pair 50, comprising gear 53 and 51 are respectively rotated about their axis. As gear 51 is rotated, it turns the superimposed feed/lift cam 48 and correction tape feed cam 72. The ribbon feed cam follower 44 is then oscillated by the rise and fall of cam 48 and acts through push/pull link 42 to move lever 38 about the axis pin 40 and engage pawl 36 with aperture 34 in feed wheel 32, thus causing feed wheel 32 to rotate. On the next succeeding character the next cam lobe of feed/lift cam 48 is presented to the cam follower 44 and the sequence of operation repeated with only a variance in the amount of arc through which lever 38 is moved. Thus on every other cycle. the feed wheel is incremented through a complete ribbon feed increment, which is in excess of the widest character to be printed.

To condition the typewriter 8 and particularlv the ribbon feed mechanism to the correction mode. the rear of the cartridge 18 is depressed manually to cause the cartridges 16 and 18 and holder 14 to rotate about the axis of rotation of holder 14. The cartridges and holder are latched in the displaced position by the latch member 122.

As holder 14 is tilted about its axis. the correction tape feed cam 72 is engaged by the tab 70 on the follower 68. As the machine then operates in the next print cycle. the push/pull link 66 is translated along with follower 68 to effect movement of the feed arm 62 about its axis pin 64 and thereby rotate tape feed wheel 60 a partial revolution corresponding to a complete correction tape feed increment. After the typehead has impacted the correction tape against the printed page. the latch member 122 is unlatched by rotation of the cyclically operated shaft. the cam 132 on which engages the cam follower 130 on the latch member 122. The latter moves to release the limb 120 on the holder 14. The holder 14 then returns to its normal rest position.

prepared to be elevated in the next machine cycle to its position corresponding to a printing position.

After the correction tape 22 or the ribbon 20 is exhausted, the cartridge with the exhausted supply is removed and replaced by a new cartridge. The removal procedure involves operation of the lever 114 to retract the arms 28 and 30 while the cartridges are lifted from and replaced on the holder 14.

The ribbon feed mechanism described operates with cartridges which have fixed axis take-up spools and provides a direct peripheral drive for uniform feed increments.

In an alternative embodiment (Figure 9), parts carrying the same reference numerals have the same or similar functions as those in the embodiment already described.

Retraction of the arms 28 and 30 is effected by a load lever 80 pivoted on a pin 82 on the frame 10. The lever 80 has an extension carrying a boss 84 engaged by a projection 86 on the arm 28 and a similar projection (not shown) on the arm 30. The load lever 80 may be manually pivoted clockwise so that the boss 84 forces the arms 28 and 30 clockwise against their respective springs 25 and 29.

The ribbon lift/feed cam 48 is driven from the shaft 52 by a worm gear 519 on the shaft 52, which engages a gear wheel 499 secured to the shaft of the cam 48. The cam follower 44 has an end 439 in engagement with the peripheral surface of the cam 48 to provide ribbon feed. The holder 14 has a depending cam follower 929 also in engagement with the peripheral surface of the cam 48 to provide lift of the holder and ribbon.

A tape feed cam 729 is not secured to the cam 48 but is mounted on the shaft 52. The push/pull link 66 is connected between the lever 62 and a cam follower 689 slidably mounted on a downward extension of the holder 14. The cam follower 689 is spring biased to one end of its limited slide on the holder and has a tab 709 extending at right angles thereto towards the cam 729.

In the lowest, intermediate and high positions of the holder and cartridges, the tab 709 is clear of the cam 729. In the highest, correction position of the holder, the tab 709 is positioned on the low portion of the cam 729. As the cam rotates with the shaft 52, a rise portion engages the tab 709 and shifts the cam follower 689 to the right against its spring. This provides correction tape feed.

In other respects, the embodiment of Figure 9 is similar to and operates in a manner similar to the embodiment of Fi gures 2, 3, 4A. 5, 6. 7 8 and 10.

WHAT WE CLAIM IS: 1. A typewriter ribbon feed and lift mechanism for a cartridge having two rib bons therein, comprising a rotatable print shaft, a holder for the cartridge mounted for oscillation, separate feed drives for the ribbons, a first cam driven by the print shaft, a first cam follower means interconnecting the first cam and one of the ribbon feed drives to effect ribbon feed upon the rotation of the first cam, a second cam follower interconnecting the first cam and the holder to effect oscillation of the holder, a second cam driven by the print shaft, and a third cam follower connected to the other ribbon feed drive and mounted for normal disengagement from the second cam and selectively movable into engagement with the second cam to effect ribbon feed upon rotation of the print shaft.

2. Mechanism according to claim 1, in which the third cam follower is selectively movable by movement of the cartridge holder beyond the limits of oscillation provided by the first cam and second cam follower.

3. Mechanism according to claim 1 or 2, in which the first cam means comprises a plurality of lobes of different rises, the rise of the highest lobe corresponding to a feed increment in excess of the widest character to be printed.

4. Mechanism according to claim 1, 2 or 3 in which the ribbon feed drives are respectively mounted on pivotally mounted arms for retraction to allow a cartridge to be mounted on the holder.

5. Mechanism according to claim 4, in which the arms are pivotally mounted on the holder.

6. Mechanism according to any preceding claim, in which the other ribbon is a correction tape and the one ribbon is a print ribbon.

7. A typewriter ribbon feed and lift mechanism for a cartridge having two ribbons therein, substantially as hereinbefore particularly described with reference to Figures 1, 2, 3, 4A, 4B, 5, 6, 7, 8. 10, 11 and 12 of the accompanying drawings.

8. Mechanism according to claim 7, modified as shown in Figure 9 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (8)

1. **WARNING** start of CLMS field may overlap end of DESC **.

   20 is exhausted, the cartridge with the exhausted supply is removed and replaced by a new cartridge. The removal procedure involves operation of the lever 114 to retract the arms 28 and 30 while the cartridges are lifted from and replaced on the holder 14.

   The ribbon feed mechanism described operates with cartridges which have fixed axis take-up spools and provides a direct peripheral drive for uniform feed increments.

   In an alternative embodiment (Figure 9), parts carrying the same reference numerals have the same or similar functions as those in the embodiment already described.

   Retraction of the arms 28 and 30 is effected by a load lever 80 pivoted on a pin 82 on the frame 10. The lever 80 has an extension carrying a boss 84 engaged by a projection 86 on the arm 28 and a similar projection (not shown) on the arm 30. The load lever 80 may be manually pivoted clockwise so that the boss 84 forces the arms 28 and 30 clockwise against their respective springs 25 and 29.

   The ribbon lift/feed cam 48 is driven from the shaft 52 by a worm gear 519 on the shaft 52, which engages a gear wheel 499 secured to the shaft of the cam 48. The cam follower 44 has an end 439 in engagement with the peripheral surface of the cam 48 to provide ribbon feed. The holder 14 has a depending cam follower 929 also in engagement with the peripheral surface of the cam 48 to provide lift of the holder and ribbon.

   A tape feed cam 729 is not secured to the cam 48 but is mounted on the shaft 52. The push/pull link 66 is connected between the lever 62 and a cam follower 689 slidably mounted on a downward extension of the holder 14. The cam follower 689 is spring biased to one end of its limited slide on the holder and has a tab 709 extending at right angles thereto towards the cam 729.

   In the lowest, intermediate and high positions of the holder and cartridges, the tab 709 is clear of the cam 729. In the highest, correction position of the holder, the tab 709 is positioned on the low portion of the cam 729. As the cam rotates with the shaft 52, a rise portion engages the tab 709 and shifts the cam follower 689 to the right against its spring. This provides correction tape feed.

   In other respects, the embodiment of Figure 9 is similar to and operates in a manner similar to the embodiment of Fi gures 2, 3, 4A. 5, 6. 7 8 and 10.

   WHAT WE CLAIM IS: 1. A typewriter ribbon feed and lift mechanism for a cartridge having two rib bons therein, comprising a rotatable print shaft, a holder for the cartridge mounted for oscillation, separate feed drives for the ribbons, a first cam driven by the print shaft, a first cam follower means interconnecting the first cam and one of the ribbon feed drives to effect ribbon feed upon the rotation of the first cam, a second cam follower interconnecting the first cam and the holder to effect oscillation of the holder, a second cam driven by the print shaft, and a third cam follower connected to the other ribbon feed drive and mounted for normal disengagement from the second cam and selectively movable into engagement with the second cam to effect ribbon feed upon rotation of the print shaft.
2. 2. Mechanism according to claim 1, in which the third cam follower is selectively movable by movement of the cartridge holder beyond the limits of oscillation provided by the first cam and second cam follower.
3. 3. Mechanism according to claim 1 or 2, in which the first cam means comprises a plurality of lobes of different rises, the rise of the highest lobe corresponding to a feed increment in excess of the widest character to be printed.
4. 4. Mechanism according to claim 1, 2 or 3 in which the ribbon feed drives are respectively mounted on pivotally mounted arms for retraction to allow a cartridge to be mounted on the holder.
5. 5. Mechanism according to claim 4, in which the arms are pivotally mounted on the holder.
6. 6. Mechanism according to any preceding claim, in which the other ribbon is a correction tape and the one ribbon is a print ribbon.
7. 7. A typewriter ribbon feed and lift mechanism for a cartridge having two ribbons therein, substantially as hereinbefore particularly described with reference to Figures 1, 2, 3, 4A, 4B, 5, 6, 7, 8. 10, 11 and 12 of the accompanying drawings.
8. 8. Mechanism according to claim 7, modified as shown in Figure 9 of the accompanying drawings.