US3604549A

US3604549A - Dual feed rate ribbon mechanism and supply cartridge therefor

Info

Publication number: US3604549A
Application number: US752096A
Authority: US
Inventors: Allison H Caudill; Willie Goff Jr
Original assignee: International Business Machines Corp
Current assignee: International Business Machines Corp
Priority date: 1968-07-16
Filing date: 1968-07-16
Publication date: 1971-09-14
Anticipated expiration: 1988-09-14
Also published as: DE1966956A1; GB1221384A; DE1966955A1; JPS498291B1; DE1934271B2; DE1966956C3; DE1966955B2; FR2014623A6; DE1934271A1; DE1966956B2

Abstract

A ribbon feed mechanism for feeding a substantially constant linear or longitudinal amount of single pass ribbon past a printing position during each ribbon feed cycle. A cartridge, which is removably mounted on a baseplate, has a supply spool and a takeup spool rotatably mounted therein with the ends of the single pass ribbon attached thereto. The bottom wall of the cartridge has a curved slot to receive a resiliently biased drive roller, which is rotatably mounted on a pivotal arm on the baseplate and has pointed projections thereon for penetrating the inked ribbon on the takeup spool to linearly advance the ribbon past its printing position. The drive roller is rotated by a gear train during each actuation of a character key on the typewriter. Means change the gear ratio of the gear train to cause a smaller amount of rotation of the drive roller during each actuation of a character key to advance the ribbon a smaller linear amount. The cartridge has a cylindrical recess to receive a portion of the gear train. When the ribbon is a solvent coated plastic transfer matrix whereby overstriking is desired, then resiliently biased means is disposed within the recess in the cartridge to render the change means operative to reduce the amount of rotation of the drive roller. If a total release ribbon is used wherein no overstriking is desired, then the recess in the cartridge is empty and the larger amount of rotation of the drive roller occurs because the change means is not rendered operative.

Description

United States Patent [72] Inventors Allison H. Caudill;

Willie Goff, Jr., both of Lexington, Ky. [211 App]. No. 752,096 [22] Filed July 16, 1968 [45] Patented Sept. 14, 1971 [73] Assignee International Business Machines Corp.

Armonk, NY. Continuation-impart of application Ser. No. 609,136, .Ian. 13, 1967, now abandoned.

[54] DUAL FEED RATE RIBBON MECHANISM AND SUPPLY CARTRIDGE THEREFOR 8 Claims, 15 Drawing Figs.

[52] US. Cl 197/151, 197/169, 197/187 [51] Int. Cl B41j 33/14 [50] Field of Search 197/151, 84, 169, 187

[56] References Cited UNITED STATES PATENTS 2,127,812 8/1938 Gabrielson 197/151 2,986,260 5/1961 Whippo 197/151 3,171,530 3/1965 ODaniel et al.. 197/151 3,346,086 10/1967 Cralle et al. 197/84 3,346,090 10/1967 Goffet al 197/151 3,349,887 10/1967 Goff 1 97/1 51 3,401,783 9/1968 Norwoodetal. 3,444,979 5/1969 Francisco ABSTRACT: A ribbon feed mechanism for feeding a substantially constant linear or longitudinal amount of single pass ribbon past a printing position during each ribbon feed cycle. A cartridge, which is removably mounted on a baseplate, has a supply spool and a takeup spool rotatably mounted therein with the ends of the single pass ribbon attached thereto. The bottom wall of the cartridge has a curved slot to receive a resiliently biased drive roller, which is rotatably mounted on a pivotal arm on the baseplate and has pointed projections thereon for penetrating the inked ribbon on the takeup spool to linearly advance the ribbon past its printing position. The drive roller is rotated by a gear train during each actuation of a character key on the typewriter. Means change the gear ratio of the gear train to cause a smaller amount of rotation of the drive roller during each actuation of a character key to advance the ribbon a smaller linear amount. The cartridge has a cylindrical recess to receive a portion of the gear train. When the ribbon is a solvent coated plastic transfer matrix whereby overstriking is desired, then resiliently biased means is disposed within the recess in the cartridge to render the change means operative to reduce the amount of rotation of the drive roller. If a total release ribbon is used wherein no overstriking is desired, then the recess in the cartridge is empty and the larger amount of rotation of the drive roller occurs because the change means is not rendered operative.

PATENTED SEPI 41am 3,604 549 sum 1 or 4 n3 H4 36 I25 III $15 finz I23 6 I r .2 II: 470 9 e, 39 1 J" fi 'll6 I45 n9 l Q I A I NVENTORS ALLISON H. CAUDILL WILLIE GOFF JR.

ATTORNEY PATENTEU SEP 1 4 I97! SHEET 2 [1F 4 FIG. 8

J m F FIG. 5

FIG.4

PATENTED SEP1 419m SHEET 3 [IF 4 DUAL FEED RATE RIBBON MECHANHSM AND SUPPLY CARTRIDGE THEREFOR This application is a continuationin-part of application Ser. No. 609,136, filed Jan. 13, 1967, now abandoned.

When a total release ribbon such as a carbon ribbon, for example, is employed with a typewriter for printing purposes, it is desired that maximum utilization of the ribbon be obtained since the ribbon makes only a single pass through a printing position. However, there can be no overstriking of a previously printed area of a carbon ribbon for satisfactory printing. Thus, when a carbon ribbon is to be fed by a ribbon feed mechanism through a printing position, it is desired that a substantially constant linear or longitudinal amount of the ribbon be metered past the printing position during each ribbon feed cycle with the amount of linear movement being sufficient to insure that there is no overstriking.

When employing a single pass ribbon of the solvent coated plastic transfer matrix type such as that shown and described in the copending application of H. T. Findley et al., Ser. No. 536,557, filed Mar. 7, 1966, now U.S. Pat. No. 3,413,184 and owned by the same assignee as the assignee of the present application, print operations may take place on the ribbon in overlapping areas. A small amount of ink is forced from small pockets in which it is entrapped. Since no time is needed for recovery after each print operation, the ribbon can be utilized in a single pass through a printing position. Thus, to obtain maximum utilization of a plastic ribbon during its single pass through the printing position, the amount of linear movement of the ribbon past the printing position is substantially smaller than that required when a carbon ribbon is employed.

In order to employ a single ribbon feeding mechanism on a typewriter in which both carbon ribbons and plastic ribbons may be employed efficiently, it is necessary to advance the ribbon past its printing position a different substantially constant linear amount depending on the type of single pass ribbon being used. With the ribbon feed mechanism of the present invention, the efficient use of either type of single pass ribbon is readily obtained.

The linear advancement of a ribbon past its printing position at substantially different linear amounts depending on the type of ribbon has been previously suggested in the copending application of Willie Goff, Jr. et al., Ser. No. 537,588, filed Feb. ll, 1966 now US. Pat. No. 3,346,090 issued Oct. 10, 1967 and owned by the same assignee as the present application. In the aforesaid Goff Jr. et al. application, two separate mechanisms are utilized to linearly advance the ribbon, depending on whether a fabric ribbon or a plastic ribbon is used, past its printing position.

In US. Pat. No. 3,171,530 to ODaniel et al., two different modes of feeding the ribbon past its printing position are employed depending on the material of the ribbon. When a fabric ribbon is used, the ribbon is linearly or longitudinally advanced during each actuation of a character key. When a plastic ribbon is employed, linear or longitudinal advancement of the ribbon occurs only after a predetermined number of actuations of typewriter character keys have occurred. During each of the predetermined number of actuations of the keys, the plastic ribbon moves transversely with respect to its printing position.

Since the ribbon feed mechanism of the present invention is utilized only for single pass ribbons, it is an improvement over the foregoing mechanisms in that it always advances whichever single pass ribbon is being used a substantially constant linear amount past the printing position throughout the entire length of the ribbon to insure maximum utilization of the ribbon. Accordingly, the present invention permits more efficient use of various types of single pass ribbons than has previously been available with ribbon feed mechanisms capable of feeding.differenttypesof ribbon.

In order to wind a ribbon on its takeup spool, a force is applied to the takeup spool. in the prior ribbon feed mechanisms, this force has been selected toprovidethe force required to wind the ribbon on its takeup spool when the maximum diameter of the ribbon is wound on the takeup spool. This is necessary to insure that a sufficient force is applied to the takeup spool to wind the ribbon thereon when the maximum diameter of the ribbon is on the takeup spool. Thus, in

the prior ribbon feed mechanisms, when only a small amount of the ribbon has been wound on the takeup spool, the force applied to the takeup spool is much greater than required whereby a greater tension exists on the ribbon.

When a plastic ribbon is being wound on its takeup spool, the application of the relatively larger force of the prior ribbon feed mechanisms to the takeup spool during initial winding of the plastic ribbon on the takeup spool may cause breaking of the ribbon. This is because the plastic ribbon is thin and relatively weak.

The present invention satisfactorily overcomes this problem by applying the ribbon winding force to the outer periphery of the ribbon, which is being wound on the takeup spool. As a result, the increasing diameter of the ribbon on the takeup spool does not affect the tensile load on the ribbon as in the prior ribbon feed mechanisms. Accordingly, the problem of a plastic ribbon breaking due to a relatively larger force applied thereto is eliminated.

This arrangement of applying the ribbon winding force to the outer diameter of the ribbon, which is wound on the takeup spool, also permits a tighter winding of the ribbon on the takeup spool so that a greater amount of the ribbon may be wound on the takeup spool for a given diameter. This is due to the present invention preventing any slippage of the ribbon wound on the takeup spool.

AS a result of the tighter winding of the ribbon on the takeup spool, the takeup spool may be substantially the same diameter as the supply spool rather than substantially larger as in prior ribbon feed mechanisms. When using a cartridge with the supply and takeup spools rotatably mounted therein, this permits a more efficient use of the space within the cartridge housing.

In order to rotatably support a spool within a cartridge housing, openings have previously been formed in both the top and bottom walls of the cartridge housing to provide bearing surface. In one embodiment, the present invention eliminates the need for any openings in the top wall of the cartridge housing so that a substantially smooth top wall is provided whereby manufacturing costs of the cartridge are reduced.

When using a cartridge, the typist is not able to see the amount of ribbon that has been advanced from the supply spool to the takeup spool. Therefore, the typist does not know when the single pass ribbon within the cartridge will be completely utilized. Thus, the possibility exists that the typist may fail to order other car other cartridges containing single pass inked ribbons in sufficient time.

One embodiment of the present invention satisfactorily solves the foregoing problem by providing indicating means on the cartridge to show the amount of inked ribbon that has been advanced from the supply spool to the takeup spool. Thus, the typist may easily discern the amount of ribbon still available for use within the cartridge.

An object of this invention is to provide a ribbon feed mechanism for advancing a single pass ribbon past its printing position at either of two substantially constant linear amounts depending on the material of the ribbon.

Another object of this invention is to provide a ribbon feed mechanism having a single drive means for advancing a single pass ribbon past its printing position at either of two substantially constant linear amounts depending upon the material of the ribbon.

A further object of this invention is to provide a ribbon feed mechanism for use with a cartridge in which a single pass ribbon is advanced linearly past its printing position at either of two substantially constant linear amounts depending upon the configuration of the cartridge.

Still another object of this invention is to provide an improved cartridge for a single pass ribbon.

A still further object of this invention is to provide an improved device for loading a cartridge on a typewriter.

Yet another object of this invention is to provide a ribbon feed mechanism for advancing an inked ribbon past its printing position in which a single means both meters the ribbon past its printing position and exerts a force on the takeup spool to wind the ribbon thereon.

A yet further object of this invention is to provide a ribbon feed mechanism having a gear train mechanism with two different gear ratios to provide two different angular amounts of rotation of the means for advancing the ribbon past its printing position depending upon the material of the ribbon.

Still another object of this invention is to provide a cartridge for an inked ribbon that is relatively inexpensive, easy to manufacture, and well adapted for plastic molding techniques.

A still further object of this invention is to provide a cartridge for a single pass inked ribbon in which the cartridge has indicating means to show the amount of ribbon still available for use within the cartridge.

The foregoing and other objects, features, and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawing.

In the drawing:

FIG. 1 is an exploded perspective view of the portion of the ribbon mechanism of the present invention attached to the typewriter.

FIG. 2 is a perspective view of one embodiment of a removable cartridge used in conjunction with the structure of FIG. 1.

FIG. 3 is a perspective view of an actuating structure used in conjunction with the structure of FIGS. 1 and 2.

FIG. 4 is a fragmentary sectional view of a portion of the cartridge of FIG. 2 and showing the mounting of one of the spools therein.

FIG. 5 is a fragmentary sectional view of another portion of the cartridge of FIG. 2 and showing the mounting of the other of the spools therein.

FIG. 6 is a perspective view showing portions of the structure of FIG. 1 in a cartridge loading and unloading position.

FIG. 7 is a plan view of a portion of a carbon ribbon and showing the pattern of printing thereon.

FIG. 8 is a plan view of a portion of a plastic ribbon and showing the pattern of printing thereon.

FIG. 9 is a perspective view of another embodiment of the removable cartridge used in conjunction with the ribbon advancing mechanism of FIG. 1 but slightly modified.

FIG. 10 is an enlarged sectional view ofa portion of the ribbon advancing mechanism of FIG. 1 modified for use with the cartridge of FIG. 9.

FIG. 11 is an enlarged perspective view of a portion of the cartridge of FIG. 9 and showing the details of the indicating device.

FIG. 12 is a fragmentary perspective view showing a modification of a portion of the ribbon advancing mechanism of FIG. 1.

FIG. 13 is a fragmentary sectional view of a portion of the cartridge of FIG. 9 and showing the mounting of one of the spools therein.

FIG. 14 is a fragmentary sectional view of another portion of the cartridge of FIG. 9 and showing the mounting of the other of the spools therein.

FIG. 15 is a fragmentary perspective view of a modified cartridge similar to that shown in FIG. 9 but arranged to be particularly suited for containing an overstrike-type ribbon.

Referring to the drawing and particularly FIG. 2, there is shown a cartridge, which is formed by housing 10. The housing 10, which is preferably formed of a lightweight plastic material, includes an upper wall 11, a lower or bottom wall 12, and a continuous sidewall 14joining the upper wall 11 and the lower or bottom wall 12.

As shown in FIG. 4, the upper wall 11 has a raised-or projecting portion 15 extending from its surface within the housing 10. A supply spool 16 is disposed within the housing 10 and has an annular end engaging the raised portion 15 of the upper wall 1 1.

The other end of the supply spool 16 has an annular portion 17, which is disposed within an opening 18 in the lower wall 12 of the housing 10. A raised portion 19 extends from the surface of the bottom wall 12 within the housing 10 for cooperation with a shoulder 20 on the supply spool 16.

The raised

portions

15 and 19 insure that an inked ribbon 21, which has one end attached to the supply spool 16, does not contact either the upper wall 11 or the lower wall 12 of the housing 10. The only support for the supply spool 16 within the housing 10 is at the lower wall 12. The cooperation between the raised portion 15 on the upper wall 11 and the end of the supply spool 16 is merely a bearing surface.

The supply spool 16 has a cylindrical passage or recess 22 extending therethrough. The wall of the passage 22 has a plurality of equally angularly spaced longitudinal passages or keyways 23 formed thereon.

As shown in FIG. 5, the housing 10 has a takeup spool 24 rotatably mounted therein the same manner as shown for the supply spool 16 in FIG. 4. The takeup spool 24 has a cylindrical passage 24' much smaller in diameter than passage 22 and does not have any keyways formed therein. The other end of the ribbon 21 is attached to the takeup spool 24.

The upper end of the takeup spool 24 bears against a raised portion 24a extending from the lower surface of the upper wall 11. This is the only contact for the upper end of the takeup spool 24. The lower end of the takeup spool 24 is disposed within an opening 24b and bears on a raised portion 246 of the lower wall 12 of the housing 10.

The ribbon 21 extends from the supply spool 16 to the exterior of the housing 10 through a slot 25, which is formed in the sidewall 14. The ribbon 21 returns to the interior of the housing 10 through a second ribbon slot 26, which is formed in the sidewall 14 of the housing 10, for attachment to the takeup spool 24.

As the ribbon 21 passes through the slot 25, it passes around an edge of the slot 25 so that this forms a guide for the ribbon 21 as it leaves the housing 10. Likewise, as the ribbon 21 passes through the slot 26, it engages an edge of the slot 26 so that this forms a guide for the ribbon 21 as it returns to the interior of the housing 10.

The housing 10 is releasably supported on a baseplate 27 (see FIG. 1). The baseplate 27 is mounted on a support member 28, which is movably along a member (not shown) across the typewriter when the present invention is employed with a single element printing head 29 (see FIG. 2) of the type described in US. Pat. 2,919,002 to Palmer. Both the single element printing head 29 and ribbon lift guides 30 (see FIG. 2), which support a portion of the ribbon 21 exterior of the housing 10, are carried by the support member 28 for movement therewith. If the present invention is used on a typewriter having a movable platen, then the baseplate 27 will be attached to the typewriter as would the ribbon lift guides 30.

The baseplate 27 has ears 31 on opposite sides thereof. Resilient elements 32, supported on the baseplate 27, cooperate with the each of the ears 31 to retain the housing 10 on the baseplate 27 during operation of the typewriter. The resilient elements 32 cooperate with the walls of slots or recesses 33 (one shown in FIG. 2) in the sidewall 14 of the housing 10.

Each of the ears 31 has portions 34 on opposite sides thereof. The portions 34 function as tops to limit downward movement of the housing 10 by engaging the bottom wall 23 of the housing 10.

When the housing 10 is moved downwardly on to the baseplate 27, a hollow shaft 35, which is rotatably mounted on a stud or spindle 36 fixed to the baseplate 27 extends into the cylindrical passage 22 in the supply spool 16. The shaft 35, which is retained on the stud or spindle 36 by a retaining clip, has splines 38 thereon for cooperation with the splines formed between the passages 23 in the supply spool 16 to insure that the supply spool 16 and the shaft 35 rotate together.

AT the same time, a stud, rod or spindle 39, which is stationarily fixed to the baseplate 27 and extends upwardly therefrom, extends into the cylindrical passage or smoother centerbore 24' within the takeup spool 24. There is no connection between the takeup spool 24 and the stud 39 so that the takeup spool 24 freely rotates or spins on the stud 39.

When the housing is moved downwardly on to the baseplate 27, a drive roller 40, which has pointed projections 41 formed thereon spaced along lines parallel to its rotational axis and around its entire periphery, extends into the housing 10 through a curved slot 42, which is formed in the bottom wall 12 of the housing 10. The drive roller 40 is rotatably mounted on a stud 43, which extends upwardly from one end of a drive roller am 44. A retaining clip retains the drive roller 40 on the stud 43. The drive roller arm 44 is mounted at its other end on the baseplate 27 through a cylindrical boss 46 being disposed within an opening 47 in the baseplate 27 for pivotal movement about an axis 47a.

When the housing 10 is moved downwardly on to the baseplate 27, the drive roller 40 has been pivotally moved from the position shown in FIG. 1 to the position shown in FIG. 6. As a result, the drive roller 40 extends into the curved slot 42 in the bottom wall 12 of the housing 10 adjacent the end of the slot 42 remote from the takeup spool 24. To prevent the pointed projections 41 on the drive roller 40 from engaging the ribbon 21 on the supply spool 16 at the time that the housing 10 is moved downwardly on to the baseplate 27 a curved shield 48 is disposed within the housing 10 adjacent the end of the slot 42 closest to the supply spool 16. The curved shield 48 preferably extends the entire distance between the upper wall 11 and the bottom wall 12 of the housing 10.

The drive roller 40 is disposed adjacent the takeup spool 24 during feeding of the ribbon 21 from the supply spool 16 to the takeup spool 24. Resilient means such as a spring 49, which has one end attached to an ear 50 on the drive roller arm 44 and its other end attached to a movable spring anchor 51, constantly urges the pointed projections 41 of the drive roller 40 into engagement with the ribbon 21 on the takeup spool 24 positively drive the takeup spool 24 across the width of the ribbon 21.

The drive roller 40 is rotated at constant angular amount during each actuation of a typewriter character key. This causes a substantially constant linear amount of the ribbon 21 to b metered past its printing position, which is where the printing head 29 engages the paper, since the ribbon 21 is positively engaged with the drive roller 40 by the pointed projections 41.

Whenever a character key of the typewriter is actuated, a motor (not shown) acting through a clutch (not shown) causes a revolution of a shaft 52 (see FIG. 3), which has a cam 53 fixed thereto for rotation therewith. The cam 53 cooperates with a cam follower 54 on a link 55, which is pivotally connected to a feed pawl 56. A spring 56, which is connected to one end of the feed pawl 56 and to the link 55, causes the feed pawl 56 to cooperate with openings 57 in a ratchet wheel 58 to provide a source of incremental motion. It should be understood that the foregoing elements move with the support member 28.

The link 55 has an opening in one end thereof to receive a stud 59 on the support member 28 to pivotally mount the link 55 thereon. A spring 60 is attached to the link 55 and to a portion of the support member 28 to cause the cam follower 54 to follow the cam 53.

The ratchet wheel 58, which is connected through a gear train 40a to the drive roller 40, is rotated a constant angular amount by the feed pawl 56 during each revolution of the shaft 52. Thus, the drive roller 40 is rotated a constant angular amount, which depends upon the gear ratio of a speed change transmission gear train 40a connecting the ratchet wheel 58 to the drive roller 40, during each actuation of a character key on the typewriter.

A detent pawl 61 is adjustably attached to the baseplate 27. The detent pawl 61 has a projection 62, which is adapted to cooperate with the openings 57 in the ratchet wheel 58, to prevent reverse rotation of the ratchet wheel 58 when the feed pawl 56 is removed from engagement with one of the openings 57 in the ratchet wheel 58 after advancing the ratchet wheel 58.

The gear train 400 includes an input gear 63 (see FIG. 1) having a cylindrical shaft 64 extending downwardly therefrom through an opening (not shown) in the baseplate 27 and an aligned opening 65 in a gear mounting block 66, which is attached to the lower surface of the baseplate 27. The shaft 64 has a reduced portion 67, which has an upper cylindrical portion 68 and a lower D-shaped portion 69. The D-shaped portion 69 fits within a D-shaped opening 70 in the ratchet wheel 58 to provide a driving connection therebetween. Thus, whenever the ratchet wheel 58 rotates, the gear 63 rotates.

The upper cylindrical portion 68 of the reduced portion 67 rotatably supports a stencil fan 71. Thus, the stencil fan 71 is disposed above the ratchet wheel 58 and does not rotate therewith.

The bottom of the shaft 64 of the gear 63 receives a threaded stud 72, which has a shoulder 72 smaller in diameter than the cylindrical portion 68 of the shaft 64. A stencil lever 73 is rotatably supported on the shoulder 72 of the stud 72 so that the lever 73 also does not rotate with the ratchet wheel 58.

The gear 63 meshes with an idler gear 74, which is rotatably supported on the baseplate 27. The idler gear 74 meshes with a gear 75, which has an upstanding shaft 76 and is rotatably mounted on the baseplate 27 through having a boss (not shown) rotatably disposed within the boss 46 of the drive roller arm 44. As previously mentioned, the drive roller arm 44 has the boss 46 extending downwardly therefrom through the opening 47 in the baseplate 27. The boss 46 also extends through an opening 77 in the gear mounting block 66. The

boss of the gear also extends within the boss 46 through the 1 gear mounting block 66.

A gear 78 is rotatably mounted on the shaft 76 of the gear 75 so as to have a common axis of rotation 47a therewith. The gear 78 has its lower surface in sliding engagement with the upper surface of the gear 75. The gear 78 has a bearing lug 79 extending upwardly therefrom and surrounding a portion of the shaft 76.

A longitudinal two-position control member 80, which has a longitudinal or cylindrical gear 81 milled on the lower portion of its outer surface, has a hollow chamber therein. This permits mounting of the longitudinal member on axis 470 over both the shaft 76 of the gear 75 and the bearing lug 79 of the gear 78. As hereinafter described, member 80 has both an upward position as shown in FIG. 1 and a depressed position.

A resilient spring 82, which surrounds the shaft 76 of the gear 75, has one end bearing against the bearing lug 79 on the gear 78 and its other end acting against a shoulder 83 of the member 80 to urge the member 80 upwardly relative to the shaft 76 and the bearing lug 79. Upward movement of the member 80 is limited by a pin 84, which extends through the shaft 76 and is carried thereby, being engaged by a planar surface 85 on the longitudinal member 80.

When the spring 82 maintains the planar surface 85 of the member 80 in engagement with the pin 84, rotation of the gear 75 results in the pin 84 engaging a projecting disc 86 on the planar surface 85 of the member 80. As a result, the member 80 rotates with the gear 75 at the same speed.

The longitudinal gear 81, which has a common axis of rotation 47a with the gear 75, is of sufficient length so as to mesh in both of the positions of member 80 with an idler bear 87. The gear 87 is rotatably mounted on the drive roller arm 44 by stud shaft 87a, and planetates about the gear 81 upon pivotal movement of the drive roller arm 44 about its axis 47a. The idler gear 87 also meshes with a gear 88 on the lower end of the drive roller 40 and integral therewith to cause rotation of the drive roller 40 whenever the gear 88 rotates.

Accordingly, when the pin 84 engages the disc 86 on the planar surface 85, the gear train drive from the ratchet wheel 58 is through the gear 63, the idler gear 75, the gear 75, the shaft 76, the pin 84, the disc 86, the longitudinal gear 81, the idler gear 87, and the drive roller gear 88. As a result, the drive roller 40 rotates a first substantially constant angular amount of an order of magnitude generally equal to individual character size during each rotation of the ratchet wheel 58 by the feed pawl 56.

This relation of the gear train 40a occurs only when a cylindrical receptacle or recess portion 89 (see FIG. 2), which is formed within the housing 10 and aligned with an opening 90 in the bottom wall 12 of the housing 10, is empty. Whether the cylindrical recess 89 is empty depends upon the material of which the ribbon 21 is formed. Thus, when the ribbon 21 is a carbon ribbon 21 (see FIG. 7) so that no overstrike of adjacent portions is desired, the recess 89 is left empty.

However, if the ribbon 21 is formed of a plastic material as is ribbon 21" in which overlapping of preceding print operations is permissible and desirable, then the cylindrical recess 89 has a disc 91 disposed therein. A resilient spring 92, which is disposed within the recess 89, urges the disc 91 toward the opening 90. A collar 93 retains the disc 91 and the spring 92 within the cylindrical recess 89.

Since the force of the spring 92 is greater than the force of the spring 82, the positioning of the housing 10 on the baseplate 27 results in the longitudinal member 80 being moved downwardly with respect to the shaft 76. Downward movement of the member 80 is possible when a pair of diametrically disposed teeth or projections 94 on the lower end of the longitudinal member 80 are aligned with a pair of diametrically disposed slots or openings 95 in the gear 78.

When the member 80 is moved downwardly with respect to the shaft 76 by the disc 91 in the housing 10 engaging the top of the member 80, the disc 86 is disposed beneath the pin 84. Thus, rotation of the member 80 by the shaft 76 through the pin 84 is no longer possible.

However, when the member 80 has moved downwardly, a connection is provided between the member 80 and the gear 78 through the teeth 94 being disposed within the slots 95 in the gear 78. Drive is now provided from the gear 75 through a gear 96, which is rotatably mounted on the baseplate 27 and the gear mounting block 66 through a threaded stud 97. The gear 96 has a second gear 98, which is preferably formed integral with the gear 96, for rotation therewith about the axis of the threaded stud 97. The gear 98 is disposed in the same plane as the gear 78 and meshes therewith to drive the gear 78.

The drive from the gear 75 through the

gears

96, 98, and 78 to the longitudinal gear 81 substantially decreases the amount of rotation of the gear 81 during each rotation of the ratchet wheel 58. As a result, the drive roller 40 is rotated a second constant angular amount of an order of magnitude, which is much smaller than the first angular amount that is produced when the gear train has a direct drive between the gear 75 and the gear 81 through the pin 84 and the disc 86.

Thus, two different angular amounts of rotation of the drive roller 40 occur depending upon the presence of absence of the disc 91 and the spring 92 within the housing 10. Accordingly, the present invention produces two different linear amounts of advancement of the ribbon 21 past its printing position depending upon whether it is desired to overstrike portions of the plastic ribbon 21" or to have no overstriking or overlapping of portions of the carbon ribbon 21'.

It should be understood that the

gears

96, 98, and 78 rotate whenever the gear 63 is rotated. However, when the teeth 94 are not disposed within the slots 95 in the gear 78, there is no connection of this portion of the gear train 40a with the longitudinal member 80.

The position of the ribbon lift guides is changed during each print cycle to change the portion of the width of the ribbon 21 disposed for engagement by the printing head 29. Thus, the ribbon 21 moves transversely during each ribbon feed cycle as well as linearly or longitudinally.

The ratchet wheel 58 has its periphery formed in the shape of a cam for cooperation with a cam follower 99 (see FIG. 3). The cam follower 99 is attached to an arm 100, which has a spring 100' attached thereto and to the support member 28 for urging the cam follower 99 into engagement with the periphery of the ratchet wheel 58. The arm 100 moves a ribbon lift guide link 101, which is connected through suitable ribbon lifting apparatus of the type shown in U.S. Pat. 2,919,008 to Whippo whereby the ribbon lift guides 30 lift the ribbon 21. This lifting of the ribbon 21 is a transverse movement of the ribbon 21 with respect to its printing position.

The cam surface on the periphery of the ratchet wheel 58 is formed with a low dwell 102, medium dwell 103, and a high dwell 104. When the cam follower 99 is in engagement with the low dwell 102, the ribbon lift guides 30 are in their uppermost position so that the bottom portion of the ribbon 21 is engaged by the printing head 29.

When the ratchet wheel 58 is rotated clockwise so that the cam follower 99 is engaging the medium dwell 103 on the ratchet wheel 58, the ribbon lift guides 30 are moved downwardly to an intermediate position whereby the middle portion of the ribbon 21 is disposed for engagement by the printing head 29. When the ratchet wheel 58 is rotated clockwise to position the cam follower 99 on the high dwell 104, the ribbon lift guides 30 will be moved to their lowermost printing position. In this position, the ribbon 21 is disposed so that its uppermost portion is engaged by the printing head 29.

It should be understood that the ribbon lift guides 30 return to a rest position, which is below the printing position, after each print cycle. This operation is more fully described in the aforesaid Whippo patent.

Ribbon spring guides and 111 (see FIG. 1) are supported by the baseplate 27. The ribbon spring guides 110 and 111 are employed to exert a resilient force on the ribbon 21 to insure that its remains taut at the printing position.

The guide 110 is mounted on arm 112, which is pivotally mounted about the axis of a screw 113 that secures the arm 1 12 to the baseplate 27. The screw 113 also retains one of the resilient elements 32 on the baseplate 27.

A spring 114 constantly urges the spring guide 110 into engagement with the ribbon 21 by urging the arm 112 to pivot about the axis of the screw 113. One end of the spring 114 is connected to an upstanding ear 115 on the arm 112 while its other end is connected to an ear 116, which extends from thebaseplate 27.

The guide 111 is attached to an arm 117, which is pivotally mounted on the baseplate 27 about the axis of a threaded screw 118 that secures the arm 117 to the baseplate 27. The screw 118 also retains the other of the resilient elements 32 on the baseplate 27.

A spring 119 continuously urges the guide 111 into engagement with the ribbon 21 by urging the arm 117 to pivot about the axis of the screw 118. One end of the spring 119 is attached to an upstanding car 120 on the arm 117 while its other end is attached to an upstanding ear 121 on the baseplate 27.

The movement of the guide 111 by the spring 1 19 is limited by engagement of the arm 117 with an ear 122, which is similar to the ear 116 and extends from the baseplate 27 Thus, the force of the spring 119 being exerted on the ribbon 21 is limited.

The arm 112 has a detent 123 mounted thereon for engagement with the teeth of a ratchet wheel 124, which is integral with the shaft 35. This prevents the ribbon 21 from spooling out and decreasing ribbon tension.

The inward movement of the guide 110 is limited by engagement of the detent 123 with one of the teeth on the ratchet wheel 124. Thus, the maximum force of the spring 114 on the ribbon 21 is also limited.

The force of the spring 114 is employed to control the tension of the ribbon 21 between the supply spool 16 and the takeup spool 24. Thus, when the tension on the ribbon 21 overcomes the spring 114 as the ribbon 21 is taken up on the takeup spool 24 by being pulled from the supply spool 16, the

ribbon 21 forces the guide 110 counterclockwise to unlock the detent 123 from the teeth of the ratchet wheel 124 to allow unspooling of the ribbon 21 from the supply spool 16. In addition to preventing unspooling of the ribbon 21 from the supply spool 16, the detent 123 also prevents rotation of the supply spool 16 due to back spacing or spacing or when typing stencils.

The

ears

116 and 122 have

upstanding lugs

125 and 126, respectively, at their ends remote from the baseplate 27. The

upstanding lugs

125 and 126 engage the bottom wall 12 of the housing to insure appropriate spacing between the bottom wall 12 and the various movable elements on the baseplate 27.

In order to permit loading and unloading of the cartridge 10 on the baseplate 27, the drive roller 40 must be positioned so as to not engage the ribbon 21, which is on the takeup spool 24, when the housing 10 is removed from the baseplate 27. Likewise, in order to permit both removal and installation of one of the housings 10 on the baseplate 27, the ribbon spring guides 110 and 111 must be removed from engagement with the ribbon 21. Furthermore, in order to permit alignment of the passages 23 of the supply spool 16 with the splines 38 on the shaft 35, it is necessary to remove the detent 123 from engagement with the ratchet wheel 124.

All of these movements are combined together through actuation of a load lever 130. The load lever 130 has an arm 131, which is pivotally mounted about the axis of the threaded stud 97.

The movable spring anchor 51 is pivotally connected to the arm 131 of the load lever 130 about the axis of an upstanding stud 132 on the arm 131. The anchor 51 has an car 133, which fits over the stud 132 and is secured thereto by a retaining clip. Accordingly, any pivotal movement of the arm 131 causes movement of the spring anchor 51.

The spring anchor 51 has a longitudinal guide slot 135 formed therein for cooperation with a shoulder screw 136, which is attached to the baseplate 27. Thus, the screw 136 serves as a guide pin for cooperation with the guide slot 135.

The arm 131 of the load lever 130 has an upstanding portion 137 at its end for engagement with an upstanding portion 138 on the drive roller arm 44. When the portion 137 engages the portion 138 due to pivoting of the arm 131 by pivoting the load lever 130, pivotal movement of the drive roller arm 44 occurs about the axis of the boss 46. This pivotally moves the drive roller 40 away from its position adjacent the takeup spool 24. The movement of the spring anchor 51 by the load lever arm 131 is such that the force of the spring 49 is relieved to permit easier movement of the drive roller arm 44 by the arm 131.

As the arm 131 pivots, a surface 139 on the portion 137 rides along an end edge 140 of the portion 138. This permits relative movement between the drive roller arm 44 and the load lever arm 131 while still permitting pivoting of the drive roller arm 44 by the arm 131.

As the drive roller arm 44 pivots, it engages an upstanding ear 141 on an arm 142, which is pivotally connected to the arm 112. The guide arm 142 has a longitudinal guide slot 143 therein for cooperation with a guide pin 144, which is attached to the baseplate 27. The arrangement of the guide slot 143 allows the guide arm 142 to move essentially along the longitudinal axis ofthe slot 143.

As a result, when the drive roller arm 44 engages the upstanding ear 141, the guide arm 142 is capable of movement essentially along the axis of the slot 143. Accordingly, the arm 112 pivots about the axis of the screw 113 to withdraw the detent 123 from engagement with one of the teeth of the ratchet wheel 124 and the spring ribbon guide 110 away from engagement with the ribbon 21.

As the guide arm 142 is moved by the drive roller arm 44, the car 141 engages a downwardly depending ear 145 on a guide arm 146. The guide arm 146 is pivotally attached to the arm 117 so that movement of the arm 146 causes movement of the guide 111.

The arm 146 has a longitudinal guide slot 147 formed able to move essentially along the axis of the slot 147. When the arm 146 is moved due to engagement of the car 141 with the ear 145, the spring ribbon guide 111 is removed from engagement with the ribbon 21. I

At substantially the same time that the ear 141 engages the ear 145, the surface 139 of the arm 131 completes movement along the end edge 1411 of the portion 138 of the drive roller arm 44. Then a surface 149 of the portion 137 on the arm 131 engages against a surface 150 on the upstanding portion 138. As a result, the arm 131 of the load lever 130 is locked in engagement with the drive roller arm 44 as shown in FIG. 6 due to the overcenter motion of the arm 131 and the force of the spring 49.

The load lever 130 has a second arm 151 (see FIG. 1), which is integral with the arm 131 and parallel thereto,

pivotally connected to the bottom of the gear-mounting block to raise the ribbon lift guides 30 upwardly in the manner shown and described in the aforesaid ODaniel et al. patent. This permits easy changing of the ribbon 21.

In this position, the ribbon spring guides and 111 are disposed away from engagement with the ribbon 21, the detent 123 is no longer engaged with the teeth of the ratchet wheel 124, the drive roller 40 is moved away from the takeup spool 24, and the ribbon lift guides 30 are moved upwardly. This permits easy removal of the cartridge housing 10 from the baseplate 27 by merely removing the ribbon 21 from the ribbon lift guides 30.

Thereafter, another of the housings 10 may be installed on the baseplate 27. Because the detent 123 is not engaged with the ratchet wheel 124, the shaft 35 can easily turn to permit alignment of the passages 23 of the supply spool 16 with the splines 38 on the shaft 35.

When the housing 10 is positioned on the baseplate 27, the drive roller 40 is disposed to enter the end of the curved slot 42 in the bottom wall 12 of the housing 10 remote from the takeup spool 24. Because of the curved shield 48, there is no danger of the projections 41 on the drive roller 40 engaging the ribbon 21 on the supply spool 16.

After the housing 10 is positioned on the baseplate 27, the load lever is moved from the position of FIG. 6 to the position of FIG. 1. As soon as the surface 149 on the portion 137 of the arm 131 is removed from locking engagement with the surface 150 on the portion 138 of the drive roller arm 44, the spring 49 causes the drive roller arm 44 to follow the pivotal movement of the arm 131 of the load lever 130 to the position of FIG. 1.

When the spring 49 withdraws the drive roller arm 44 from engagement with the ear 141 on the guide arm 142, the spring 114 moves the arm 112 clockwise about the axis of the screw 113 to return the detent 123 into engagement with one of the teeth of the ratchet wheel 124. This also returns the ribbon spring guide 1 10 into biasing engagement with the ribbon 21.

Since the ear 141 is moved out of engagement with the ear due to the movement of the arm 112 by the spring 114, the spring 119 urges the ribbon spring guide 111 into engagement with the ribbon 21. This movement of the arm 117 by the spring 119 is limited by engagement of the arm 117 with the lug 126 on the ear 122,

The drive roller 40 is moved into engagement with the portion of the ribbon 21 on the takeup spool 24 by the spring 49. The engagement of the drive roller 40 with the ribbon 21 on the takeup spool 24 stops movement of the drive roller arm 44 by the spring 49.

Considering the operation of the present invention, the cartridge has the housing 10 assembled with the ribbon 21 wound on and having one end attached to the supply spool 16, which is rotatably mounted within the housing 10. The ribbon 21 extends from the supply spool 16 through the ribbon slot 25 in the sidewall 14 of the housing to the exterior of the housing 10. The ribbon 21 is returned through the ribbon slot 26 in the sidewall 14 of the housing 10 and around the takeup spool 24 to which it is attached.

With the cartridge so packaged, it is ready for use by a typist, The ribbon 21 is positioned in the ribbon lift guides 30 through maneuvering the cartridge so that it is not necessary for the typist to grasp the ribbon 21. The ribbon 21 is disposed in front of the single element printing head 29 as shown in FIG. 2.

When it is desired to position the cartridge housing 10 on the baseplate 27, the load lever 130 is in its loading and unloading position (see FIG. 6). in this position, the guides 110 and 111 are moved away from the path of the ribbon 21 so that the typist may easily maneuver the ribbon 2l'within the ribbon lift guides 30.

With the ribbon 21 positioned with the ribbon lift guides 30 and in front of the printing head 29, the housing 10 is moved downwardly with the cylindrical passage 22 in the supply spool 16 positioned above the shaft 35, the cylindrical passage 24' in the takeup spool 24 positioned above the stud or spindle 39, and the curved slot 42 positioned in alignment with the drive roller 40. Because the detent 123 is not engaged with the teeth of the ratchet wheel 124, the shaft 35 is free to rotate to permit alignment between the passages 23 of the supply spool 16 and the splines 38 on the shaft 35. This permits the passages 23 and the splines 38 to be aligned so that the housing 10 may be moved downwardly.

As the housing 10 moves downwardly, the ears 31 on the baseplate 27 enter the slots 33 in the sidewall 14 of the housing 10. Downward movement of the housing 10 is stopped by engagement of the housing 10 with the portions 34 on each of the ears 31, the

upstanding lugs

125 and 126, and

upstanding lugs

154 and 155, which are disposed on the opposite side of the baseplate 27 from the

ears

116 and 122, which have the

lugs

125 and 126.

With the housing 10 abutting against the

upstanding lugs

125, 126, 154, and 155 and the portions 34 of the ears 31, the shaft 35 is disposed within the cylindrical passage 22 of the supply spool 16, the spindle or stud 39 is disposed within the cylindrical passage 24 in the takeup spool 24, and the drive roller 40 extends within the housing 10 through the slot 42. At this time, the drive roller 40 is adjacent the curved shield 48. The resilient elements 32 hold the housing 10 on the baseplate 27 to prevent movement of the housing 10 during typing operations.

As the housing 10 is moved downwardly on the baseplate 27, the longitudinal member 80 extends upwardly through the opening 90 in the bottom wall 12 of the housing 10 into the cylindrical recess 89 within the housing 10. It will be assumed that the cylindrical recess 89 is empty. This is the arrangement when the ribbon 21 is a carbon ribbon and no overlapping of printing on the ribbon 21 is to be permitted. As a result, the longitudinal member 80 is biased by the spring 82 to the position in which the pin 84 will engage the disc 86 to cause a direct connection between the gear 75 and the longitudinal gear 81 for rotation.

During each actuation of a character key of the typewriter, the drive roller 40 is rotated clockwise a substantially constant angular amount due to rotation of the ratchet wheel 58 by the feed pawl 56. Because there is a direct connection between the gear 75 and the longitudinal gear 81 through the pin 84 and the disc 86, the drive roller 40 rotates the larger of the two angular amounts, which it is rotated by the gear train for each rotation of the ratchet wheel 58.

At the same time, each actuation of the ratchet wheel 58 moves the cam follower 99, which is biased into engagement with the periphery of the ratchet wheel 58 by the spring 100', from one of the three

dwells

102, 103, 104 to the next of the three dwells I02, 103, 104. This results in the ribbon 21 being moved transversely with respect to the printing head 29 at the same time that it is being moved linearly or longitudinally with respect to the printing head 29 by the drive roller 40.

Referring to FIG. 7, there is shown the pattern of characters imprinted on the ribbon 21' during each actuation of the ribbon feed mechanism with the ribbon 21 being a carbon ribbon. With the ribbon 21' assumed to be moving to the right and being viewed from the printing element side of the ribbon 21, six printing positions 156-161 are shown on the ribbon 21.

It is assumed that the printing area 156 is the first. This occurs with the ribbon lift guides 30 in their uppermost position whereby the lowermost portion of the ribbon 21' is disposed for engagement by the printing head 29. The printing area 157, which is next, occurs with the lift guides 30 in their intermediate position while the printing area 158 occurs with the ribbon lift guides 30 in their lowermost printing position.

With the width of the type characters assumed to be 0.100 inch, each of the linear movements of the ribbon 21 past the printing position due to angular rotation of the drive roller is 0.037 inches. Accordingly, when the ribbon lift guides 30 are returned to their uppermost position from their lowermost position, the area 159 is linearly or longitudinally spaced from the area 156 because the three linear movements of the ribbon 21 are greater than the width of a type character This insures that there is no overstriking of a ribbon area, which has already been utilized for printing.

If the ribbon 21 within the housing 10 is a plastic ribbon in which overstriking or overlapping of the print areas on the ribbon 21 is desired, then the housing 10 has the disc 91 and the spring 92 mounted therein as previously discussed. Accordingly, when the housing 10 is moved downwardly to be locked on the baseplate 27, the disc 91 engages the top of the longitudinal member 80 to urge it downwardly. Since the force of the spring 92 is greater than the force of the spring 82, the member 80 is moved downwardly provided that the teeth 94 on the member 80 are disposed in alignment with the slots 95 in the gear 78 at this time.

If the teeth 94 of the longitudinal member 80 should not be aligned with the slots 95 in the gear 78 at the time that the housing 10 is moved downwardly, then the gear ratio will still be that due to the connection between the gear 75 and the longitudinal gear 81 through the pin 84 and the disc 86 until the longitudinal member has been rotated so that the teeth 94 of the member 80 are vertically aligned with the slots in the gear 78.

When the teeth 94 are disposed within the slots 95, the gear ratio is changed to substantially reduce the angular rotation of the drive roller 40 during each rotation of the ratchet wheel 58 by the feed pawl 56. This reduces the linear movement of the ribbon 21 past its printing position.

Accordingly, with the ribbon 21" being plastic, the positioning of the various print areas on the ribbon 21" will be as shown in FIG. 8. Areas l62-l67 designate six areas on the ribbon 21" in which printing occurs with the first occurring at the area 162 and the last at the area 167 when the ribbon 21" moves to the right.

There is the same amount of vertical movement of the ribbon lift guides 30 during each rotation of the ratchet 58 as when the ribbon 21 is carbon. However, the linear movement of the ribbon 21" past the printing position is substantially reduced due to the substantially smaller constant angular amount of rotation of the drive roller 40. Of course, this linear amount of movement is substantially constant.

With the type character width being approximately 0.100 inch, the linear movement of the ribbon 21" is only 0.006 inch, which is approximately one-sixth of the movement when the ribbon 21 is carbon. This, by the time that the area 165 is engaged by the printing head 29, the leading edge of the area 165 is disposed only 0.0l8 inch from the leading edge of the area 162. As a result, there is a substantial overlap of the print areas when the ribbon 21 is plastic. The leading and trailing edges of the areas 165-167 have been shown dotted to emphasize the overlapping.

After the ribbon 21 has been fully used, it is only necessary to again move the load lever 130 to its loading and unloading position. As previously mentioned, this removes the detent 123 from one of the teeth of the ratchet wheel 124, the drive roller 40 from engagement with the ribbon 21 on the takeup spool 24, the ribbon spring guides 110 and 111 from engagement with ribbon 21, and raises the ribbon lift guides 30. This permits the housing to be easily removed from the base plate 27, and another of the housings 10 to be disposed thereon.

As soon as the housing 10 is removed from the base plate 27, the spring 82 urges the teeth 94 of the longitudinal member 80 out of engagement with the slots 95 in the gear 78. However, the teeth 94 remain aligned with the slots 95 so that if another of the housings 10 having a plastic ribbon 21" therein is positioned on the baseplate 27, the teeth 94 will again return into the slots 95 to cause immediate changing of the gear ratio of the gear train 40a to that required for the ribbon 21 when it is plastic.

Of course, if the housing 10, which is to be disposed on the baseplate 27, has a carbon ribbon 21' therein rather than a plastic ribbon 21" therein, then the recess 89 within the housing 10 is empty. As a result, the drive roller 40 is automatically rotated the greater angular amount upon the initial rotation of the ratchet wheel 58.

This arrangement insures that the larger linear ribbon feed increment always occurs whenever the housing 10 has a carbon ribbon 21' therein. As previously mentioned, this larger linear amount of movement may occur for a short period of time when the housing 10 has a plastic ribbon 21" therein until the teeth 94 are aligned with the slots 95.

While the housing 10 has been described as being utilized until all of the ribbon 21 therein has been used, it should be understood that the housing 10 may be removed at any stage of use of the ribbon 21 therein. This permits the typist to make a quick and easy change from a plastic ribbon 21" to a carbon ribbon 21' and vice versa without having a to touch the ribbon 21 and without having to waste any of the carbon ribbon 21 or the plastic ribbon 21" since the unused portion of the ribbon 21 may be readily employed when the housing 10 is again disposed on the baseplate 27.

After the housing 10 has been disposed on the baseplate 27, the load lever 130 is returned to the position of FIG. 1 in which the detent 123 engages the teeth of the ratchet wheel 124, the guides 110 and 111 engage the ribbon 21, the drive roller 40 is disposed adjacent the takeup spool 24 so that the pointed projections 41 are engaged with the ribbon 21 on the takeup spool 24, and the ribbon lift guides 30 are in their normal uppermost position.

Because the spring 49 constantly urges the drive roller 40 so that the pointed projections 41 penetrate the inked ribbon 21 on the takeup spool 24, a positive engagement is always provided between the drive roller 40 and the inked ribbon 21 on the takeup spool 24 irrespective of the diameter of the ribbon 21 on the takeup spool 24. As the diameter on the takeup spool 24 increases, the drive roller 40 moves along the curved slot 42 in the housing 10 away from the takeup spool 24.

Since the advancement of the ribbon 21 from the supply spool 16 to the takeup spool 24 is governed by the angular rotation of the drive roller 40, the diameter of the increasing ribbon 21 on the takeup spool 24 does not affect the linear movement of the ribbon 21 past the printing head 29. Accordingly, the same linear amount of the ribbon 21 is advanced during each actuation of the ratchet wheel 58 because of the projections 41 having positive engagement with the ribbon 21.

Furthermore, the engagement of the projection-s 41 with the ribbon 21 on the takeup spool 24 provides the only force to wind the ribbon 21 on the takeup spool 24. Since'the. force of the spring 49 is applied toward the center of the takeup spool 24, it dies not affect the tension of the ribbon 21 but merely squeezes the ribbon.21 toward the center of the takeup spool 24.

When it is desired to use the typewriter for cutting a stencil wherein the ribbon 21 is not to be used, the stencil lever 73 is rotated clockwise. The lever 73 has a pair of spaced ears and 171 between which is disposed a downwardly projecting portion 172 of the stencil fan 71. Thus, when the stencil lever '73 is rotated clockwise, the lug 170 on the lever 73 engages the projection 172 to move the stencil fan 71 therewith.

A spring (not shown) constantly biases the lever 73 counterclockwise to the normal position in which no stencil is to be cut. In this position in which no stencil is to be cut, the periphery of the lever 73 has a low point 173, which clears the cam follower 99 even when the follower 99 is engaging one of the low dwells 102 on the cam surface of the ratchet wheel 58. As a result, there is no effect on the cam follower 99 when the stencil lever 73 is not activated. However, when the stencil lever 73 is rotated clockwise against the force of the biasing spring, the follower 99 is moved out of engagement with the cam surface on the ratchet wheel 58 by a curved surface 174 on the periphery of the stencil lever 73.

When the stencil lever 73 has rotated clockwise until the follower 99 has traversed the entire length of the surface 174, the follower 99 falls off the surface 174 and engages a detent surface on the lever 73. When this occurs, further movement of the lever 73 is prevented and the stencil fan 71 is positioned to prevent the feed pawl 56 from engaging the openings 57in the ratchet wheel 58. Accordingly, when the stencil lever 73 is actuated, there can be no feeding of the inked ribbon 21.

Additionally, by moving the cam follower 99 completely out of engagement with the periphery of the cam surface of the ratchet wheel 58, the follower 99 moves the ribbon lift link 101 so that the ribbon 21 remains disposed in its rest position beneath the printing position as shown and described in the aforesaid Whippo patent. Thus, the ribbon 21 also is removed from the printing position when the stencil lever 73 is moved,

When engagement between the follower 99 and the detent surface 175 of the lever 73 ceases due to moving the lever 73 counterclockwise, the spring (not shown) biases the lever 73 counterclockwise until the lug 170 engages a stop, which is a tab (not shown) depending downwardly from the baseplate 27. At this time, the lug 171 is engaged with the projection 172 of the stencil fan 71 since it is engagement between the lug 171 and the projection 172 that results in the fan 71 being returned from its blocking position to its unblocking position,

The stop for the lever 73 is positioned so that the low point 173 on the periphery of the lever 73 is disposed opposite the follower 99. Thus, the follower 99 may be engaged with one of the low dwells 102 on the cam surface of the ratchet wheel 58 without any interference by the stencil lever 73.

Referring to FIG. 9, there is shown another form of cartridge, which is formed by a housing 180. The housing 180, which is preferably formed of a lightweight plastic material, includes an upper wall 181, a lower or bottom wall 182, and a continuous sidewall 183 joining the upper wall 181 and the lower or bottom wall 182.

The housing has a supply spool 184 rotatably mounted therein between the upper wall 181 and the lower wall 182. The supply spool 184 includes a main body 185 (see FIG. 13) and a removable upper portion 186. The removable upper portion 186 includes a circular plate 187, which bears against the lower surface of the upper wall 181. Fingers 188 extend downwardly from the lower surface of the circular plate 187 for disposition within recesses 189 in the main body 185. Thus, when one of the portions of the supply spool 184 is rotated, the other portion must rotate because of the cooperation between the fingers 188 on the circular plate 187 and the recesses 189 in the main body 185.

The upper surface of the circular plate 187 has a knob 190 projecting through an opening 191 in the upper wall 181 of the housing 180. Thus, when the knob 190 is rotated, the supply spool 184 isrotated.

The lower end of the main body 185 has a reduced annular portion 192, which is disposed within an opening 1.92 in the lower-wall 182 of the housing 180. A raised annular portion 194 extends from the upper surface of the bottom wall 182 within the housing 180 for cooperation with a shoulder 195 on the main body 185 of the supply spool 184. Thus, the raised portion 194 and the circular plate 187 insure that an inked ribbon 196, which as one end attached to the main body 185 of the supply spool 184, does not contact either the upper wall 181 or the lower wall 182 of the housing 180.

The main body 185 of the supply spool 184 has a cylindrical passage or recess 197 extending therethrough. The wall of the passage 197 has a plurality of equally angularly spaced longitudinalsplines or ribs 198 formed thereon. It should be understood that the splines or ribs 198 cooperate with passages or grooves (not shown), which would be formed in the shaft 35 instead of the splines 38. Thus, the same type of arrangement exists between the shaft 35 and the main body 185 of the supply spool 184 as exists between the shaft 35 and the supply spool 16. However, instead of the supply spool 184 having passages or grooves formed therein for cooperation with splines 38 on the shaft 35 as the supply spool 16 does, the supply spool 184 has the splines 198 formed on the main body 185 with the passages to receive the splines 198 being formed in the shaft 35.

The upper end of each of the splines or ribs 198 forms the bottom of one of the recesses 189 that receive the fingers 188. Accordingly, when the knob 190 is turned, the shaft 35 is turned when the splines 198 are disposed in the passages in the shaft 35.

The housing 180 has a takeup spool 199 rotatably mounted therein. As shown in FIG. 14, the takeup spool 199 includes a main body 200 and a removable upper portion 201. The removable upper portion 201 is the same as the removable upper portion 186 of the supply spool 184. That is, it includes a circular plate 202 having fingers 203 extending downwardly therefrom and a knob 204 extending upwardly from the circular plate 202 through an opening 205 in the upper wall 181. The fingers 203 are disposed within slots 206 in the main body 200.

The lower end of the main body 200 of the takeup spool 199 is formed with a reduced annular portion 207, which is disposed within an opening 208 in the lower wall 182 of the housing 180. An annular raised portion 209 extends from the upper surface of the bottom wall 182 within the housing 180 for cooperation with a shoulder 210 on the main body 200 of the takeup spool 199. Thus, the lower end of the main body 200 of the takeup spool 199 is supported in the same manner as the main body 185 of the supply spool 184. The main body 200 has a cylindrical passage 211 therein of much smaller diameter than the passage 197 and does not have any splines formed therein. The other end of the ribbon 196 is attached to the main body 200 of the takeup spool 299.

The ribbon 196 extends from the supply spool 184 to the exterior of the housing 180 through a slot 212, which is formed in the sidewall 183 of the housing 180. The ribbon 196 returns to the interior of the housing 180 through a second ribbon slot 213, which is formed in the sidewall 183 of the housing 180, for attachment to the takeup spool 199.

As the ribbon 196 passes through the slot 212, it passes around an edge of the slot 212 so that his forms a guide for the ribbon 196 as it leaves the housing 180. Likewise, as the ribbon 196 passes through the slot 213, it engages an edge of the slot 213 so that this forms a guide for the ribbon 196 as it returns to the interior of the housing 180.

However, after entering the housing 180 through the ribbon slot 213, the ribbon 196 passes around a curved shield 214, which is the same as the shield 48 in the housing 10, before being attached to the takeup spool 199. Thus, this arrangement of the path of the inked ribbon 196 produces more angular wrap around the takeup spool 199 of the ribbon 196 before it is engaged by the drive roller 40 than the arrangement of FIG. 2.

When the inked ribbon 196 passes around the convex surface of the shield 214, the inked side of the inked ribbon 196 is in engagement with the convex surface of the shield 214.

Since this inked side of the ribbon 196 will have an uneven surface due to its previously having been utilized at the printing position, this uneven surface may cause an accumulation of particles on the convex surface of the shield 214. If such an accumulation of particles on the surface of the shield 214 were to occur, this buildup of the particles on the shield 214 would result in drag on the ribbon 196.

Accordingly, the convex surface of the shield 214 may have a coating of a material with a smooth surface such as Teflon, for example, thereon to eliminate any buildup of particles. Thus, drag due to such particles is eliminated by using a material having a smooth surface. The coating of Teflon may be a tape, for example. Of course, any other suitable means for applying the coating may be utilized.

It should be understood that the housing 180 is releasably supported on the baseplate 27 in the same manner as is the housing 10. Furthermore, the lower wall 182 of the housing 180 has a curved slot 215, which is similar to the curved slot 42 in the housing 10, therein to receive the drive roller 40 in the same manner as the drive roller 40 is received in the housing 10.

As shown in FIGS. 9 and 11, the upper wall 181 of the housing 180 has a curved slot 216 receiving an extension on the stud 43 on which the drive roller 40 is rotatably mounted. Since the stud 43 moves with the drive roller 40 during its movement through the curved slot 215 as the ribbon 196 is advanced from the supply spool 184 to the takeup spool 199, the extension on the stud 43 may have an indicating mark 218 thereon for cooperation with a scale 219 on the upper surface of the upper wall 181. The scale 219 may have indicia to indicate the amount of the ribbon 196 that has been advanced from the supply spool 184 to the takeup spool 199 by indicating either the amount of the ribbon 196 on the supply spool 184 or the amount of the ribbon 196 on the takeup spool 199. As shown in FIG. 11, the indicia on the scale 219 indicate the amount of the ribbon 196 on the takeup spool 199. If the indicia were to indicate the amount of the ribbon 196 on the supply spool 184, the symbol E, which indicates empty, and the symbol F, which indicates filled, would be reversed. Similarly, any suitable scale such as percentage of ribbon remaining, number of typed pages remaining, or continuous remaining typing time could be employed.

Thus, since the indicating mark 218 is on the extending end of the stud 43, the advancement of the drive roller 40 through the curved slot 216 results in the advancement of the extension of the stud 43 through the slot 216. Thus, the indicating mark 218 moves with the drive roller 40 as it advances along the curved slot 215 due to the increase in the amount of the ribbon 196 on the takeup spool 199.

While the housing 10 has been shown as having the spring 92 mounted therein for cooperation with the disk 91 to change the gear ratio for changing the linear advancement of the ribbon 21 during each cycle, the housing 180 has a different construction in which no spring is utilized within the cartridge. Instead, the housing 180 merely has a recess portion 220 therein, see FIG. 9. For ribbons capable of receiving overlapping pring operations, a modified cartridge housing 180 is employed as shown in FIG. 15 and is formed with a recess 220' of a lesser depth than the recess 220 employed for socalled total release ribbons.

The longitudinal member is replaced by a cylindrical shaped member 221 (see FIG. 10) having a gear 222 on its lower end instead of the longitudinal gear 81. The gear 222 must have sufficient thickness to mesh with the idler gear 87 in either of the two positions of the member 221. The lower end of the gear 222 has teeth 94' mounted thereon in the same manner as the lower end of the gear 81 for cooperation with the slots in the gear 78.

The gear 75, which meshes with the idler gear 74, is carried on a threaded shaft 223 rather than the shaft 76. The threaded shaft 223 extends upwardly within the interior of the member 221. The shaft 223 is provided with a pin 224, which extends from diametrically disposed sides of the shaft 223, while two pairs of diametrically disposed passages or slots 225 (one shown in FIG. are in the top of the member 221 to cooperate with the pin 224. The shaft 223 and the member 221 thus have cooperating means thereon to cause rotation of the member 221 by the gear 75 though the shaft 223 when the spring 82 is efiective to cause the pin 224 and the slots 225 to interengage. When the spring 82 is effective, the pin 224 is disposed in one of the substantially perpendicular pairs of the passages 225 whereby the gear 75 rotates the member 221 through the shaft 223 and the pin 224.

The threaded end of the shaft 223 has an adjusting nut 226 thereon. The adjusting nut 226 controls the clearance of the teeth 94' from the gear 78 when the spring 82 is effective.

The member 221 has a resilient compression spring 228 mounted in surrounding relation thereto. One end of the compression spring 228 is fixedly secured to the cylindrical shaped member 221 adjacent the gear 222. The spring 228 replaces the spring 92, which is used with the cartridge housing 10 of FIG. 2.

When the ribbon 196 is a carbon ribbon so that no overstrike is desired between the adjacent portions of the ribbon 196, the recess 220 in the housing 180 is formed with a greater depth (This is shown in FIG. 9.) than if the ribbon 196 is formed of a plastic material in which overlapping of preceding print operations is permissible and desirable. Thus, when the ribbon 196 is a carbon ribbon, the greater depth of the recess 220 in the housing 180 permits the spring 228 to be extended to its maximum length so that the spring 82 will be effective to produce the driving of the drive roller 40 through the shaft 223. However, when the inked ribbon 196 is formed of a plastic material in which overlapping of preceding print operations is permissible and desirable, the depth of the recess 220 (see FIG. is less so that the bottom surface of the recess engages the top of the spring 228 when the housing 180 is mounted on the baseplate 27. As a result, the spring 228 is effective to overcome the force of the spring 82 and cause the teeth 94 to be disposed in the slots 95 in the gear 78.

While the housing 180 has been shown as having the sidewall 183 connecting the upper wall 181 to the lower wall 182, it should be understood that a continuous sidewall is not necessary. Thus, it is only necessary that ribbon guides be provided for the ribbon 196 as it leaves the housing 180 and as it returns to the housing 180. This also would be applicable as to the housing 10.

While the housing 180 has been described as having the scale 218 on the upper wall 181 for cooperation with the extension of the stud 43 to indicate the amount of the inked ribbon 196 advanced from the supply spool 184 to the takeup spool 199, it would be understood that the indicating means could be utilized with the housing 10. Thus, it would only be necessary to provide a curved slot, similar to the curved slot 216, in the upper wall 1 1 of the housing 10, to extend the stud 43 to protrude through the curved slot in the upper wall 11, and to have an indicating mark on the extension of the stud 43 for cooperation with a scale, which is similar to the scale 219, on the upper surface of the upper wall 11 of the housing 10. This would indicate the amount of the inked ribbon 21 that has been advanced from the supply spool 16 to the takeup spool 24.

It should be understood that the housing 10 could have the recess 220 for use with the cooperating structure of FIG. 10 in the manner shown for the housing 180. Likewise, the housing 180 could have the recess 89 for use with the cooperating structure of F l6. 1 in the manner shown for the housing 10.

The drive roller 40 is driven in the same manner when the housing 180 is employed as when using the housing 10 of FIG. 2. The primary difference is that the spring 228 is now mounted on the ribbon advancing mechanism rather than the spring 92 being mounted in the housing 10 of the cartridge. Of course, the shaft 223 also is different.

lt is desirable to wind a large diameter of ribbon on the

takeup spool

24 or 199. This large diameter imposes a large increase in length on the extension spring 49 which could result in an overstressed nonlinear force-distance spring response. This nonlinear response is provided by anchoring one end of the spring 49 to one end of a coiled torsion spring 230. The other end of the torsion spring 230 is secured to. a stud 231 on a movable spring anchor 232, which is similar to the spring anchor 51. However, the movable spring anchor 232 has its slot 233, which is similar to the slot 135 in the movable spring anchor 51, open at the opposite end from the slot 135. The torsion spring 230 is retained on the stud 231 by. a retaining clip.

The slot 233 receives the shoulder screw 136 in the same manner as does the slot 135. Thus, the screw 136 serves as a guide pin for cooperation with the guide slot 233 in the movable spring anchor 232. It should be understood that the movable spring anchor 232 is pivotally connected to the arm 131 of the load lever about the axis of the upstanding stud 132 on the arm 131 in the same manner as is the movable spring anchor 51.

While the

ribbons

21 and 196 have been described as being moved transversely as well as longitudinally or linearly during each actuation of a character key, it should be understood that the present invention could be utilized with fixed ribbon guides rather than the movable lift guides 30. Of course, this would require greater linear movement of the ribbon 21 or- 196 during each feed cycle but the ratios, depending onwhether the

ribbons

21 and 196 are plastic or carbon, would stay the same.

While this invention has been shown and described with. respect to a typewriter using a single element printing head, it should be understood that it can be used with a typewriter having a movable platen.

An advantage of this invention is that it requires only a single drive mechanism for driving a single pass ribbon as two dif ferent speeds. Another advantage of this invention is that it insures maximum use of aninked ribbon, which passes only once through its printing position. A further advantage of this. invention is that it insures that a desired constant linear amount of ribbon is advanced past the printing position during each feed cycle of the ribbon in accordance with the material of the ribbon. Still another advantage of this invention is that it permits easy loading and unloading of a ribbon cartridge on its support structure. A still further advantage of this invention is that the ribbon may be installed without the typist having to. touch the ribbon.

While the invention has been particularly shown and described with reference to preferred embodiments thereof, it' will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

1. A typewriter ribbon feed mechanism for selectively advancing a first or second type of ribbon, and including base means supporting first and second spindles for respectively receiving supply and takeup spools containing an ink ribbon attached therebetween wherein the improvement comprises:

a ribbon drive roller for engaging a peripheral portion of.

ribbon wound on said takeup spool.

an arm supported on said base means for pivotal movement about an axis and rotatably supporting said ribbon drive roller at a location distal from said axis,

resilient means urging said arm toward said second spindle,

a source of incremental motion, and

speed change transmission means interconnected between said ribbon drive roller and said motion source and including a two-position control member movably mounted at a location that is stationary with respect to said axis for selectively interconnecting said motion source through said speed incremental transmission means to said ribbon drive roller to convert said incremental motion into increments of motion of a first order of magnitude or into increments of motion of a second order of magnitude that is substantially less than said first order of magnitude.

2. A typewriter ribbon feed mechanism as defined in claim 1, further comprising:

a cartridge containing said supply and takeup spools and being removably receivable by said base means, said cartridge having a portion thereof selectively constructed to differentially cooperate with said control member in dependence upon the type of ribbon contained in the cartridge to position said control member in one of its two positions.

3. A typewriter ribbon feed mechanism as defined in claim 1 wherein said ribbon drive roller has pointed projections on its periphery at spaced locations for penetrating the ink ribbon on said takeup spool across its width to provide engagement therewith.

4. A typewriter ribbon feed mechanism as defined in claim 1 wherein:

said second spindle consists of a rod mounted stationarily with respect to said base means, and

said takeup spool comprises a smooth centerbore that is freely rotatably received by said rod.

5. A typewriter ribbon feed mechanism as defined in claim 1 further comprising resilient means biasing said two-position control member to one of its positions.

6. A typewriter ribbon feed mechanism as defined in claim 2 wherein:

said speed change transmission means comprises a plurality of gears, and

said control member in its said one position establishes a driving connection through a first series of said gears and in its other position establishes a driving connection through a second series of said gears including at least one gear not included in said first series.

7. A typewriter ribbon feed mechanism as defined in claim 1 wherein:

said speed change transmission means comprises a plurality of gears, including a gear formed integrally with said twoposition control member and mounted for rotation about said arm pivot axis, and

said control member in one of its two positions establishes a driving connection through a first series of said gears and in its other position establishes a driving connection through a second series of said gears including at least one gear not included in said first series.

8 A typewriter ribbon feed mechanism as defined in claim 1 wherein said speed change transmission means comprises:

first resilient means for yieldably exerting a force on said control member tending to position said control member in one of its positions,

second resilient means selectively activatable to urge said control member in opposition to said first resilient means at an increased force level with respect thereto so that said control member is displaced from its said one position to its other position upon activation of said second resilient means, and

at least one pair of rotatable parts which are selectively engageable only when mutually aligned in a predetermined relationship, engagement of said parts being controlled by the position of said control member, and means connecting one of said parts with said motion source for rotation so that relative rotation of said parts by said motion source during resilient urging of said control member toward its said other position by said control resilient means enables engagement between said parts when said parts become properly aligned.

Claims

1. A typewriter ribbon feed mechanism for selectively advancing a first or second type of ribbon, and including base means supporting first and second spindles for respectively receiving supply and takeup spools containing an ink ribbon attached therebetween wherein the improvement comprises: a ribbon drive roller for engaging a peripheral portion of ribbon wound on said takeup spool. an arm supported on said base means for pivotal movement about an axis and rotatably supporting said ribbon drive roller at a location distal from said axis, resilient means urging said arm toward said second spindle, a source of incremental motion, and speed change transmission means interconnected between said ribbon drive roller and said motion source and including a twoposition control member movably mounted at a location that is stationary with respect to said axis for selectively interconnecting said motion source through said speed incremental transmission means to said ribbon drive roller to convert said incremental motion into increments of motion of a first order of magnitude or into increments of motion of a second order of magnitude that is substantially less than said first order of magnitude.

2. A typewriter ribbon feed mechanism as defined in claim 1, further comprising: a cartridge containing said supply and takeup spools and being removably receivable by said base means, said cartridge having a portion thereof selectively constructed to differentially cooperate with said control member in dependence upon the type of ribbon contained in the cartridge to position said control member in one of its two positions.

4. A typewriter ribbon feed mechanism as defined in claim 1 wherein: said second spindle consists of a rod mounted stationarily with respect to said base means, and said takeup spool comprises a smooth centerbore that is freely rotatably received by said rod.

6. A typewriter ribbon feed mechanism as defined in claim 2 wherein: said speed change transmission means comprises a plurality of gears, and said control member in its said one position establishes a driving connection through a first series of said gears and in its other position establishes a driving connection through a second series of said gears including at least one gear not included in said first series.

7. A typewriter ribbon feed mechanism as defined in claim 1 wherein: said speed change transmission means comprises a plurality of gears, including a gear formed integrally with said two-position control member and mounted for rotation about said arm pivot axis, and said control member in one of its two positions establishes a driving connection through a first series of said gears and in its other position establishes a driving connection through a second series of said gears including at least one gear not included in said first series.

8. A typewriter ribbon feed mechanism as defined in claim 1 wherein said speed change transmission means comprises: first resilient means for yieldably exerting a force on said control member tending to position said control member in one of its positions, second resilient means selectively activatable to urge said control member in opposition to said first resIlient means at an increased force level with respect thereto so that said control member is displaced from its said one position to its other position upon activation of said second resilient means, and at least one pair of rotatable parts which are selectively engageable only when mutually aligned in a predetermined relationship, engagement of said parts being controlled by the position of said control member, and means connecting one of said parts with said motion source for rotation so that relative rotation of said parts by said motion source during resilient urging of said control member toward its said other position by said control resilient means enables engagement between said parts when said parts become properly aligned.