US3327830A - Ribbon shift mechanism for typewriters - Google Patents

Description

June 27, 1967 Wl E REXFORD 3,327,830

RIBBON SHIFT MECHANISM FOR TYPEWRITERS Filed April 23, 1964 4 Sheets-Sheet l r T1 E...

INVENTOR M//A./ /s E'. REX/fana June 27, 1967 w. E. REXFORD RIBBON SHIFT MECHANIsM FOR TYPEWRITERS 4 Sheets-Sheet 2 Filed April 25, 1964 I N V EN TOR. lA//L f s E. PEA/Popo June 27, 1967 w. E. RExFoRD 3,327,830

RIBBON SHIFT MECHANISM FOR TYPEWRITERS Filed April 25, 1964 4 Sheets-Sheet 5 INVENTOR. M///s E. REX/@H0 June 27, 1967 w. E. REXFORD 3,327,830

RIBBON SHIFT MECHANISM FOR TYPEWRITERS Filed April 25, 1964 4 sheets-sheet 4 INVENTOR l4///s f'. REX/:aren

ATTORNE YS United States Patent O York Filed Apr. 23, 1964, Ser. No. 361,965 7 Claims. (Cl. 197-157) This invention relates to typewriters and, more particularly, to a novel ribbon shift mechanism by means of which either of a pair of sections of a ribbon, such as a red section or a black section, may be readily selected for engagement by a type bar by proper preselection of the fulcrum point of a lever forming part of the ribbon shift mechanism.

In a known form of typewriter, the escapement mechanism for providing step-by-step advance of the carriage includes an oscillatably mounted pawl mechanism cooperable with a rack. This pawl mechanism is also utilized as a means for raising a ribbon into proper position for engagement by a type bar, while maintaining the ribbon otherwise lowered so as to expose the typed material to view. In this known arrangement, a projection, such as a spring finger or a spring wire, extends from the pawl mechanism and has its free end engaged in a ribbon guide mounted for upward sliding movement. With a mechanism of this type, whenever a typing key is struck, it actuates, through a universal bar mechanism, the pawl mechanism is a direction such as to effect advance of the carriage and at the same time to lift the ribbon into position for engagement by the type bar.

In accordance with the present invention, it has been found that, by a slight change in the lever shifting mechanism operated by such pawl mechanism, the ribbon, when elevated by the pawl mechanism, may be elevated to either one of two selected positions so that a selected section of the ribbon is positioned in the path of movement of the type bar. Thus, for example, a two-color ribbon may be used and either color may be selec-ted at will.

` position as it is biased toward More specically, instead of the projecting vfinger of the pawl mechanism engaging directly with the ribbon guide, this finger is made to engage a pivoted ribbon shifting lever which, in turn, has its free end connected to the ribbon guide. Thereby, each time the pawl mechanism is rocked, the free end of this lever is moved upwardly and thus the ribbon guide is moved upwardly. Thereby, the ribbon is positioned in the' path of movement of the type bar eachtime a typing key is struck.

To provide for selection of the position to which the ICC substantially perpendicular to the direction of movement of the ribbon shifting lever, and this pivot selection lever has arcuate lingers projecting from opposite ends thereof. When the pivot selection lever is swung in one direction, one arcuate finger will move through an aperture inthe bracket wall and into the then aligned fulcrum aperture of theribbon shifting lever, and conversely when the pivot selection lever is rocked in the opposite direction, its other finger will move through the corresponding aperture in the wall of the bracket and into -the then aligned aperture in the ribbon shifting lever.

The pivot selection lever is so designed that only one finger at a time can serve as a pivot for the ribbon shifting lever, and means are further provided so that the pivot selection lever may be moved only when a typing key is not operated, with movement of the pivot selection lever being blocked during operation of a typing key. During a small portion of the throw of the pivot selection lever, both fingers -are engaged with the ribbon shifting lever, to prevent complete disengagement of the pivot selection lever from the ribbon shifting lever. Such twofinger engagement of the pivot selection lever with the ribbon shifting lever occurs only at an intermediate position of the throw of the pivot selection lever, and the pivot selection lever can not remain in such intermediate either end position by a toggle spring.

For an understanding of the principles of the invention, reference is made to the following description of a typical embodiment thereof as illustrated in the accompanying drawings. In the drawings:

FIG. 1 is a right side elevational view of a typewriter having the ribbon shifting mechanism of the invention incorporated therein;

FIG. 2 is a partial plan View of sponding to FIG. 1, with those not directly associated with the being shown in broken lines;

FIG. 3 is a rear elevational view, taken along line 3 3 of FIG. 1;

FIGS. 4 and 5 are views, taken on the line 4-4 of FIG. 3, and illustrating the pivot selection lever in its two different positions; v

FIG. 6 is a sectionalview taken on the line 6-6 of FIGS. 3 and 4;

FIG. 7 is a View taken on the typewriter, correparts of the typewriter ribbon shifting mechanism partly in section,

the line 1 7 of Frog-i i and illustrating the high lift position ofthe ribbon shift'- ribbon is lifted responsive to operation of a typing key, 7

a pair of fulcrum points are provided for the ribbon shifting lever, these fulcrum points being spaced longitudinally ofthe lever. For a short throw or short lift ofthe lever, the lever is arranged to be pivoted at the fulcrum point which is furthest from its free end connected to the ribbon guide and, for a long throw or high lift of the lever, the lever is -arranged to be fulcrumed at the fulcrum point which is nearer to the free end thereof connected to the ribbon guide.

Selection of the fulcrum point is provided in a novel manner. Specifically, the ribbon shifting lever is a substantially flat piece of metal which is relatively elongated and is mounted in substantial juxtaposition to an upwardly extending substantially flat bracket. This bracket has a pair of apertures therethrough which are spaced from l each other longitudinally of the extent of the ribbon shifting lever, and this lever is likewise formed with a pair of apertures therethrough which are in correspondingly longitudinally spaced relation. A rocking pivot selection lever is pivoted so as to be movable in a plane ing lever; I

FIG. 8 isa section taken on the line 8 8 of FIG. 5 and illustrating -the low lift position of the ribbon shifting lever;

FIG. 9 is a view similar` to -FIGQ villustrating the ribbon raised to the Vhigh lift position;

FIG. l0 is a View similar to FIGS. 6 and 9 illustrating the ribbon raised to the low or short lift position;

FIG. 11 is a view similar to FIG. 7, taken onvthe line 11-11 of FIG. 9; and

FIG. 12 is a view similar to FIG. 8, taken on the line 12-12 of FIG. 10.

Solely -by way of example, the ribbon shifting mechanism of the present invention is illustrated as incorporated in the typewriter of the type of the kind shown anddescribed in copending application Serial No. 264,843, filed March `13, 1963 fby Willis E. Rexford for Typewriter, now Patent No. 3,223,220 issued December 14, 1965 and assigned to the assignee of the present application. However, it should be understood that the invention-is applicable to any form of typewriter in which an esoapement mechanism includes an os-cillating pawl mechanism which is also used to lift a ribbon guide.

Referring to FIGS. 1, 2 and 3, the typewriterselected f for illustration includes a support base 20 which may be a sheet metal stamping, and which is formed with an lupstanding peripheral rim 21 andprovided with support feet 22. A shell or partial cover (not shown) for the typewriter may be secured tothe rim 21 of base 20 in any desired manner. Base 20 has secured thereto sheet meta-l brackets supporting the various elements of' the typewriter. There are two principal brackets including a forward bracket, generally indicated' atl 25, and a rear, or carriage guide, bracket. generally indicated at 30'. These brackets may be secured to base 20 in any desired manner.

Bracket 25 has the function of sup-porting the universal bar or rod 100 controlling the ri'bbon feed and carriage escapement responsive to actuation of the typing keys or the space bar, and further supporting a pivot rod or axle 89 for bell crank levers 75, operated by the individual' keys, and for the space bar support arms or levers 81. For this purpose, bracket 25'includes upstanding arms 26 each formed with a horizontally extending slot 27 near its upper end, and which are arranged to guidingly receive universal bar 100 for bodily lateral displacement.

Rear bracket 30 supports the carriage assembly, the type bar basket, the 'ribbon spools, the ribbon guides, and other parts cooperative with these components. Bracket 30 includes a generally channel shaped sheet metal member 31 extending transversely of base 20 adjacent the rear edgefthereof, channel shape member 31 having a base 32 secured to support base 20, and a rear wall 33, and a pair of laterally spaced front walls 34. Bracket 30 furthere includes a pair of generally vertical side members or walls 35 which are mirror copies of each other. The outerends of lwalls 33 and 34 are formed with tongues projecting therefrom which extend through correspondingly located slots in each side wall 35 and are twisted over to anchor these sidewalls to channel member 31.

Each side wall 35 is formed with a pair of horizontal ears 44 extending outwardly on either side of a notch 43 in its upper edge, and the ears 44 serve to support the carriage assembly, and further act, in cooperation with notch 43, to form a bearing or crank 4member 185 operating the carriage escapement mechanism.

Forwardly of channel' mernber 31, each side wall 35 is lformed adjacent its lower edge with a vertically extending slot 46 for a purpose to be described. A tongue 40 extends from the upper edge of each side wall 35 and has a forked upper end forming an outwardly opening notch which serves as a ribbon guide means. Tongues 40 are twisted out of the general plane of each side wall 35 at an angle of about 45 degrees, and it will be noted that the forward arm 39 of each ribbon guide extends a little above the rear arm 39" thereof. The upper portion of each wall 35 extends forwardly beyond ribbon guide 40 to form an extension 47 formed with a pair of vertically spaced and aligned outwardly extending apertured horizontal ears 48 which conjointly receive a drive spindle 115 for a ribbon spool 110.

The type bar basket, which is generally indicated at 50, is essentially conventional except for being shifted to select between different characters onthe type bars. Basket 50 includes a casting 54 secured to a plate 57, and is-formed with outwardly opening radially extending slots 58 each of which receives the pivot end of a type bar lever 55. The pivot ends of levers 55 are apertured to receive a pivot rod or shaft 59 and, each type bar lever 55 has a type lbar 60 secured thereto. Each type bar 60 is a casting carrying a pair of'characters 62 spaced longitudinally thereof, with casting 60 being anchored to the free end of the associated lever 55.

Mounting plate 57 for the type basket slides on a support plate or bracket 63 secured to channel member 31 at its upper end and secured to support base 20 at its lower end. Intermediate its ends, support bracket 63 is formed with a relatively large notch 64 and an angled ear 65 on the rear surface of plate 57 projects through notch 64 and rearwardly of bracket 63. Ear 65 has a pair of apertures therein for a purpose to be described.

Plate 57 is guided for rectilinear movement along support bracket 63 in any suitable manner, and plate 57 along with -type basket 50 is biased to an upper limit of movement by tension springs connected between plate 57 and the front walls 34 of channel member 31.

The keyboard of the typewriter includes typing keys 70, a space bar 80, and shift keys. Each typing ykey has an operating head or button 76 having printed or otherwise provided on its face the characters of the associated type bar i60. Space bar 80 is supported upon a pair of 'levers 81. Each typing key is operatively connected to its associated type bar 55 through the -medium of a bell crank '75. The guiding structure for the keyboard elements is in the nature of a key comb `having slots receiving each of the levers for the space bar, the typing keys, and the shift keys. This comb also has slots for the bell cranks connecting the respective keys to the respective type bars.

The guiding means for the key-bar levers further includes a guiding element 101 which is an angular cross section member formed of sheet metal and having its base suitably secured to main support base 20. This guiding element has slots therein for the various keyboard levers, and these slots are aligned with the slots of the comb.

The typing` keys may be biased to the upper position, or clockwise as viewed in FIG. 1, by a rubber spring device 105. Spring device 105 comprises achannel 106 having its base suitably anchored to support base 20 and formed with a series of upwardly opening slots each receiving one of the typing keys 70;

As previously stated, the type basket is biased upwardly by suitable spring means engageab-le between bracket 31 and mounting plate 57. Shifting between lower and upper casecharacters is eiected by lowering the type bar basket 50 rather than by raising the carriage assembly. Referring especially to FIG. 6 together with FIG. 3 of the aforesaid copending application, now Patent 3,223,220, each shift lever has an aperture at its rear end substantially aligned with the vertically extending slots 46 in end walls 35 of rear bracket 30. Each shift lever 85v has associated therewith a rod 114, and each rod 114 extendsthrough the aperture in the associated shift lever 85, through the adjacent vertically elongated slot 46, and through a horizontally elongated slot 52 in an ear 51 of rear bracket 30. The inner ends of rods 114 are engaged in the respective apertures in ear 65 on plate 57. When either shift lever is operated, it is swung in a counterclockwise direction as viewed in FIG. 1 to move the outer end of its associated rod 114 upwardly in the adjacent vertically extending slot 46. The inner portion` of each rod 114 thereupon moves downwardly about its fulcrum in slot 52 to move ear 65 downwardly and thus mounting plate 57 downwardly. Due to the inclined motion of ear 65, rod 114 will slide horizontally in slot 52.

The operation of feeding the ribbon and advancing the carriage, responsive to operation of a typing key or of the space bar, is effected by the universal rod or bar 100. Rod extends lengthwise of forward bracket 25, with its ends projecting through horizontal slots 27 and these slots support rod 100 which is biased rearwardly into engagement with arms of the bell cranks and with arms on space bar levers 81 by spring means (not shown). Each time a key 70 is depressed, its associated bell crank is rocked counterclockwise, and each time the space bar 80 is depressed, upwardly extending arms thereon also move in a counterclockwise direction. Each of these movements of a bell crank or of the arms on the space bar levers advances universal rod or bar 100 parallel to itself in a direction forwardly of the typewriter. This bodily sidewise. reciprocation of universal bar or rod 100 is used to eiect such actions as step-by-step advancing of the ribbon and operation of the escapement mechanism for the carriage.

Ribbon spools or reels are mounted on the upper ends of vertical shafts 115 which are provided with gears 116 for suitable rotation thereof to advance the ribbon step-by-step. Such rotation is effected by worms on a shaft 120. Rotation of shaft 120 to advance the ribbon in either direction is effected by a pawl or rack 125 engageable with a ratchet gear 130 secured on shaft 120. This pawl is angular in cross section and has a generally vertical leg having an elongated slot 126 having a width somewhat greater than the diameter of shaft 120. An arm 127 extends angularly upwardly and forwardly from this vertical wall and is formed with an aperture receiving universal bar 100. Ribbon 90 is on the spools 110 and, between these spools, the ribbon is guided through the slots and arms 40, and through a vertically movable ribbon guide 135. Ribbon guide 135 is slidably mounted, for vertical movement, upon mounting plate 57, and, in a conventional manner, mounting plate 57 is formed with a pair of guide ears 131 for guiding the type bars into arcuately centered position when a key 7 0 is struck. Ribbon guide 135 is formed with ribbon guiding ngers 132 through which ribbon 90 extends.

In the normally lower position of ribbon guide 135, ribbon 90 is displaced away from guide ears 131 so that the typed matter is visible. As a key 70, or space bar 8l), is struck, ribbon guide 135 is moved upwardly so that ribbon 90 is positioned in the path of movement of a type bar 60 on a type bar lever 55. Guide 135 is a substantially flat piece of sheet metal which engages the back or rear surface of mounting plate 57, and the guide has ears 133 bent around each edge of plate 57 and overlying the front surface thereof.

The carriage assembly includes a fixed channel shaped track 140 over which is telescoped an inverted channel shaped movable slide 150 constituting the carriage. The base of track 140 is apertured adjacent each end so that it may be secured by screws or the like to horizontal ears 44 on the side walls of rear bracket 30. Each flange of track 140 is formed with an outwardly facing V-shaped recess extending longitudinally thereof. Correspondingly, the anges of movable channel slide 150 are formed with inwardly facing V-shaped recesses extending longitudinally thereof and aligned with the aforementioned V- shaped recess in track 140. These facing recesses receive ball bearing assemblies each comprising ball bearings 142. By means of ball bearings 142, slide 150 and the elements supported thereby are freely movable longitudinally of track 140.

The base of track 140 has a pair of apertured ears 143 struck out therefrom at longitudinally spaced locations, and between these ears there is a substantially rectangular aperture cut from the base.

The carriage assembly, the elements of which are mounted upon movable slide 150, is biased to the left as viewed from the front of the typewriter so that, under the control of the escapement mechanism, the carriage assembly will step to the left each time a key 70 or space bar y80 is operated. The biasing means comprises a suitable spring means, such as a relatively elongated coil spring. The base of slide 150 has ears 156 extended from each end thereof and bent vertically upward and apertured to receive pivots for a cylindrical platen 155. A plastic knob 157 is secured to each end of the platen shaft for rotating the same to set and advance the paper. A suitable paper guide, and suitable spring bias rollers, are provided for guiding the paper and for maintaining it in contact with platen 155. p

The escapement mechanism for the typewriter includes a rack 175 movable with slide 150 and cooperable with a pawl mechanism generally indicated at 180 and operated by movement of universal bar or rod 100. In a manner described more fully hereinafter, pawl mechanism 180 is oscillatably mounted in apertured ears 143 of track 140 and extends across the rectangular aperture in the base of the track. This pawl mechanism is oscillated by means of crank 185, and crank 185 is connected to universal bar 100 by means of offset links 170 apertured at each end to receive bar 100 and the ends of crank 185. The

arrangement is such that, each time universal bar 10) is moved sideways by operation of a key 70 or space bar 80, crank member 185 is oscillated and this actuates escapement mechanism 180.

As best seen in FIG. 3, crank 185 is a relatively elongated rod which is bent, adjacent each end, to form two rectangular offsets providing pivot axes 181 which lie in and extend through notches 43 between horizontal ears 44 of rear bracket Sti. These two offsets provide a relatively elongated central section 182 extending between the two offsets, and crank ends 183 which are engaged through apertures in the rear ends of links 170. Central crank section 182 serves to oscillare pawl mechanism 180 responsive to movement of universal bar 100.

In the typewriter construction described and claimed in said aforementioned application Serial No, 264,843, oscillation of the pawl mechanism 180 acts directly to lift the ribbon guide to position ribbon 90 in the path of movement of the character 62 on type bars 55, the particular character 62 which strikes the ribbon being determined by whether or not the type basket is lowered as by depressing a shift lever, or is in its normal raised position. In the present invention, oscillation of pawl mechanism 180 is still utilized to raise and lower ribbon guide 135. However, novel means are provided whereby the amount by which ribbon 135 is raised or lifted is determined by the setting of a ribbon shift lever. Thus, ribbon 90 is `divided intro two sections including an upper section 90A and a lower section 98B, and these are usually of two different colors, such as black and red or blue and red, for example. The ribbon shift mechanism is designed to select which one of the two differently colored sections 90A or 90B is positioned in the path of movement of the character 62 on type bars 55.

Referring to FIGS. 1 and 2, a ribbon shifting key 95, which may be an angular piece of substantially iiat sheet metal, is pivoted at 91 to an end wall 26 of front bracket 25. A wire link 92 has a bent forward end which extends through an aperture in ribbon shift key 95, intermediate the ends of the latter, so that link 92 is pivotally connected to key 95. Link 92 is of somewhat offset Construction so that it extends inwardly of an end wall 26 of front bracket 25 and inwardly of the universal bar links 170. The rear end of link 92 is pivotally connected in the eye 93 of a bent end 94 of a crank shaft 96. Crank 96 extends through allgned apertures in one end wall of rear bracket 30 and in a rearwardly projecting substantially vertical leg 144 of an upright bracket arranged in closely spaced parallel relation to front wall portion 34 of rear bracket 30 adjacent the left side of the typewriter as viewed from the front. Beyond leg 144, ribbon shift crank 96 has a second bent end 97 extending substantially parallel to the bent end 94,

Bracket 145 is maintained in arcuately spaced substantially parallel relation with wall 34 by means of a bolt or stud 146 and a spacer 147 interposed between bracket 145 and wall 34, Intermediate its ends, and substantially midway of its height, bracket 145 is formed with a struck out tongue 148 which lies in a plane which extends upwardly to the right as viewed in FIG. 3. Ear 148 has a threaded aperture receiving a pivot stud 149 for a pivot selection lever which is swinga-ble about stud 149 in a plane parallel to the surface of ear 148. Bracket 145 is also formed with a pair of longitudinally spaced and relatively large diameter apertures 151 and 152 which are aligned along a rectilinear line which is the center line of the pivot selection lever 160. Aperture 151 is concentric with a corresponding aperture 153 in wall 34, but aperture 152 is located beyond the inner edge of wall 34. The purpose of apertures 151, 152 and 153 will become clear as the description proceeds.

lRibbon guide 135 has an odset downward extension 136 which, for the major portion of its length, extends substantially perpendicular to support base 20. Extension 136, adjacent its lower edge, is for-med with a transversely extendingslot 137 which receives a bent end 166 of a ribbon shifting lever 165. The major portion 4of lever 165 is positioned in juxtaposed relation to the inner surface of bracket 145, and lever 165 has its end portion opposite to its free end having the hook end 166 in juxtaposed relation with wall portion 34. Somewhat inwardly from free end 166, ribbon shifting lever 165 is formed with an aperture receiving the bent end 167 of a wire or rod link 168 which has a bent end 169 at its opposite end engaged in an aperture in a wall of pawl mechanism 180. Thus, each time pawl mechanism 180 is swung by crank 185 through operation of universal bar 100, link 168 will be moved upwardly and thus will move ribbon shifting lever 165 and the ribbon guide 135 upwardly. The amount of such upward movement or lift is determined by cooperating components which will now be described in detail.

Ribbon shifting lever 165 is formed with a pair of longitudinally spaced apertures 171 and 172 which have a longitudinal spacing corresponding to that of the lapertures 151 Aand 152 in bracket 145. Apertures 171 and 172 are substantially smaller in diameter than are apertures 151 and 152. The apertures 171 and 172 are arranged to cooperate with pivot pin ends 161 and 162 on opposite ends of pivot selection lever 160. These pivot pin ends extend inwardly and `are substantially arcuate in plan, as best seen in FIGS. 4 and 5, for example. When pivot selection lever 160 occupies the position of FIG. 4, pivot linger 162 is extended through apertures 152 and 172. In this position, the lift of bent end 166 of ribbon shifting lever 165, responsive to movement of link 16S, is a maximum ldue to the relatively short distance between bent end 167 of link 168 and the then eiiective pivot aperture 172 of lever 165.

When pivot selection lever 160 occupies the position of FIG. 5, pivot iinger 161 is engaged through apertures 151, 171 and 153. In this position of pivot selection lever 160, the lift of the free end 166 of lever 165 is at a minimum due to the relatively long distance between bent end 167 of link 168 and the then effective pivot aperture 171. It should be noted that, in response to each oscillation of pawl mechanism 180, the amount of lift of link 168 is exactly the same. The only thing which is changed is the effective lever arm of bent end 167 with respect to one of the pivot apertures 171 or 172.

With the construction so far described, it will be apparent that, when ribbon selecting key 95 is moved from the position shown in FIG. l, to its opposite position, crank 96 will be rocked clockwise, as viewed in FIG. l. Through bent end 97 of crank 96, this will swing lever 160 counterclockwise, as viewed in FIG. 4. Such swinging of lever 160 Will withdraw pivot arm 162 from its associated aperture 172 in lever 165, and project pivot arm 161 through aperture 171 in lever 165. To maintain lever 160 in either of its operated positions, a toggle spring 173 has one end hooked into an aperture in lever 160 and its other end hooked into an aperture in a tab 174 on wall 34.

It is important that the ribbon selecting means be operable only when the typewriter keys are at rest and no key is depressed. For this reason, special means are provided to block the then unused aperture 171 or 172 when lever 165 is pivoted about the center of the other aperture. Referring to FIGS. ll and 12, adjacent aperture 172, lever 165 is formed with an enlargement or projection 163 and, adjacent aperture 171, lever 165 is formed with an enlargement or projection 164. FIGS. 7 and 8 illustrate lever 165 in the position which it normally occupies in the absence of depression of a key 70 or space bar 80. In the positions shown in FIGS. 7 and 8, both apertures 171 and 172 are aligned with the respective apertures 151 and 152 in bracket 45 and with the fingers 161 and 162 of pivot selection lever 160. Therefore, pivot selection lever 160 may be rocked from one position to the other when the parts occupy the position of FIG. 7 or FIG. 8.

FIGS. l1 and 12 illustrate the position of lever`165` when swung clockwisefby upward movement of link 168y due to rocking of pawl mechanism 180. Referring to FIG. 11, wherein pivot arm 162 is illustrated as engaged in aperture 172, enlargement 164 blocks both apertures 151 and 153, as well as forming an obstruction to inward movement of pivot arm 161. In FIG. l2, wherein pivot arm 161 is engaged in aperture 171, enlargement 163 blocks pivot arm 162 from inward movement, as illustrated in broken lines.

The positions occupied by lever 160 and lever 165, when selector key 95 has the position of FIG. 1, are illustrated in FIGS. 4, 7, 9 and 1l, with FIG. 7 illustrating the parts in their at rest position. When a typing key is struck, pawl mechanism 180 is rocked to lift link 168.Y

This pivots lever 165 clockwise about pivot arm 162, resulting in ribbon guide 135 being lifted to its maximum lift position. This maximum litt position is shown in FIGS. 9 and 11, wherein it will be noted that ribbon 90 is moved to a position wherein the lower sectoin 90B of the ribbon is aligned with the lower case character 62 on type bar 60 of a type lever 55. Of course, if the shift lever had also been operated to lower the type basket, lever 55 would also have been lowered so that the lower section 90B of ribbon 90 would then be aligned with the upper case character 62.

FIGS. 5, 8, 10 and 12 illustrate the operation when the lever 165 is to be given its minimum lift. Referring to these figures, FIGS. 5 and 8 show the pivot arm 161 engaged through aperture 171 of lever 165. FIG. 8 illustrates the rest position in which no typing key nor the space bar have been struck. When a typing key 70 or space bar is struck, the resultant rocking of pawl mechanism 180 moves link 168 upwardly the same amount as in the case of the arrangement previously described. In this case, however, lever 165 is pivoted about pivot arm 161 and consequently the lift of the free end of `the lever is a minimum and only to the position shown in FIG. l2. In this instance, the lift of ribbon is such that only the upper section 90A is aligned with a lower case character 62 on a type bar 6i).

Again, if the shift key had been depressed, the type basket would have -been lowered, and upper section 90A of ribbon 90 would have been aligned with the upper case character 62 of the type bar 60. These figures just described represent the position of the parts when selector key is swung clockwise to swingcrank 96 clockwise to thereby pivot selection lever from the position shown in FIG. 4 to that shown in FIG. 5.

The arrangement shown is simple, inexpensive, and foolproof in operation. While it has been described with reference to a particular typewriter for the purpose of giving an example of the application of the invention, it will be quite clear that the ribbon shifting mechanism may be` used with any typewriter in which movement of a ribbon guide is effective responsive to oscillation of a pawl mechanism included in the carriage escapement control means.

While speciiic embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. In a typewriter having typing keys, type bars operable by said keys, a universal bar operated by said keys, a carriage, a platen on said carriage, a two-color ribbon, and a ribbon guide mounted for substantially vertical reciprocation between a rest position, maintaining said ribbon out of the path of movement of the type bars, and a working position, maintaining said ribbon adjacent said platen in the path of movement in the type bars: ribbon shifting means for ribbon color selection comprising, in combination, a relatively elongated ribbon shifting lever mounted for substantially vertical oscillation and having a free end pivoted to said ribbon guide; means, including an operator pivotally connected to said ribbon shifting lever at a rst point thereon inwardly of said free end, effective to rock said ribbon shifting lever to lift said free end responsive to operation of said universal bar; said ribbon shifting lever being formed with rst and second pivot means between said rst point and the opposite end of said lever and spaced lo-ngitudinally of said lever; sai-d pivot means, respectively providing a low lift and a high lift of the free end of said ribbon shifting lever upon rocking thereof by said operator; a pivot selector lever mounted adjacent said ribbon shifting lever and having lirst and second pivot bearing means respectively engageable with said lirst and second pivot means; said pivot selec-ting lever being pivotable relative to said ribbon shifting lever between a first position, in which said rst pivot bearing means is operatively engaged with said first pivot means and said second pivot bearing means is disengaged from said second pivot means,

c bearing means comprising `bearing pins on opposite ends of said pivot selector lever selectively engageable in the adjacent aperture in said ribbon shifting lever.

3. In a typewriter, ribbon shifting means as claimed in claim 1, in which said ribbon shifting lever is a subof said plates; said one plate being formed with a pair of apertures spaced a distance corresponding to the spacing of 'the apertures in said ribbon shifting lever and 10 each of said pivot pins being aperture in said one plate.

4. In a typewriter, ribbon shifting mechanism, `as claimed in claim 3, in which `said pivot selector lever is a substantially liat metal strip and said pins constitute extensions from 'the ends of said strip, each of said extensions being relat1vely narrow and being -arcuate about of said pivot selector lever.

5. In a typewriter, ribbon shifting means, as claimed in claim l, said carriage being displaceable and said typewriter including escapement displacement of said carriage responsive to operation of said universal bar and said escapement mechanism including an oscillatably mounted pawl mechanism; said aligned with a respective ing lever upon oscillation of said pawl mechanism responsive to operation of said universal bar.

`6. In a typewriter, ribbon shifting means, as claimed in claim 1, in which said ribbon shifting lever is a substantially flat metal strip; said strip having lateral eX- tensions therefrom adjacent each of the pivot apertures therein; each such lateral extension, in the working position of said ribbon guide, blocking the then disengaged pivot pin from entry into its associated pivot aperture whereby said ribbon may be shifted only when said ribbon guide is in said rest position.

7. In a typewriter, ribbon shifting means, as claimed in claim 1, including toggle means maintaining said pivot selector lever in each of its operated positions.

References Cited UNITED STATES PATENTS 860,361 7/1907 Felbel 197-157 2,387,785 10/1945 Walker 197-159 X 2,705,553 4/1955 Thomson 197`l51 X 3,057,449 10/ 1962 Thomson 197-22 3,223,220 12/ 1965 Rexford 197-22 FOREIGN PATENTS 84,415 6/1921 Austria.

ROBERT E. PULFREY, Primary Examiner. E. T. WRIGHT, Assistant Examiner.

Claims (1)

1. IN A TYPEWRITER HAVING TYPING KEYS, TYPE BARS OPERABLE BY SAID KEYS, A UNIVERSAL BAR OPERATED BY SAID KEYS, A CARRIAGE, A PLATEN ON SAID CARRIAGE, A TWO-COLOR RIBBON, AND A RIBBON GUIDE MOUNTED FOR SUBSTANTIALLY VERTICAL RECIPROCATION BETWEEN A REST POSITION, MAINTAINING SAID RIBBON OUT OF THE PATH OF MOVEMENT IN THE TYPE BARS; AND A WORKING POSITION, MAINTAINING SAID RIBBON ADJACENT SAID PLATEN IN THE PATH OF MOVEMENT IN THE TYPE BARS: RIBBON SHIFTING MEANS FOR RIBBON COLOR SELECTION COMPRISING, IN COMBINATION, A RELATIVELY ELONGATED RIBBON SHIFTING LEVER MOUNTED FOR SUBSTANTIALLY VERTICAL OSCILLATION AND HAVING A FREE END PIVOTED TO SAID RIBBON GUIDE; MEANS, INCLUDING AN OPERATOR PIVOTALLY CONNECTED TO SAID RIBBON SHIFTING LEVER AT A FIRST POINT THEREON INWARDLY OF SAID FREE END, EFFECTIVE TO ROCK SAID RIBBON SHIFTING LEVER TO LIFT SAID FREE END RESPONSIVE TO OPERATION OF SAID UNIVERSAL BAR; SAID RIBBON SHIFTING LEVER BEING FORMED WITH FIRST AND SECOND PIVOT MEANS BETWEEN SAID FIRST POINT AND THE OPPOSITE END OF SAID LEVER AND SPACED LONGITUDINALLY OF SAID LEVER; SAID PIVOT MEANS, WHEN EFFECTIVE, RESPECTIVELY PROVIDING A LOW LIFT AND A HIGH LIFT OF THE FREE END OF SAID RIBBON SHIFTING LEVER UPON ROCKING THEREOF BY SAID OPERATOR; A PIVOT SELECTOR LEVER MOUNTED ADJACENT SAID RIBBON SHIFTING LEVER AND HAVING FIRST AND SECOND PIVOT BEARING MEANS RESPECTIVELY ENGAGEABLE WITH SAID FIRST AND SECOND PIVOT MEANS; SAID PIVOT SELECTING LEVER BEING PIVOTABLE RELATIVE TO SAID RIBBIN SHIFTING LEVER BETWEEN A FIRST POSITION, IN WHICH SAID FIRST PIVOT BEARING MEANS IS OPERATIVELY ENGAGED WITH S AID FIRST PIVOT MEANS AND SAID SECOND PIVOT BEARING MEANS IS DISENGAGED FROM SAID SECOND PIVOT MEANS, AND A SECOND POSITION, IN WHICH SAID SECOND PIVOT BEARING MEANS IS OPERATIVELY ENGAGED WITH SAID SECOND PIVOT MEANS AND SAID FIRST PIVOT BEARING MEANS IS DISENGAGED FROM SAID FIRST PIVOT MEANS; A RIBBON POSITION SELECTOR MOVABLE BETWEEN TWO POSITIONS, EACH CORRESPONDING TO A DIFFERENT RIBBON COLOR; AND LINKAGE INTERCONNECTING SAID RIBBON POSITION SELECTOR LEVER BEARING PIVOT SELECTOR LEVER; SAID PIVOT SELECTOR LEVER BEING MOUNTED FOR PIVOTAL MOVEMENT ABOUT AN AXIS IN A PLANE SUBSTANTIALLY PERPENDICULAR TO THE PLANE OF OSCILLATION OF SAID RIBBON SHIFTING LEVER; SAID PIVOT MEANS COCMPRISIN APERTURES IN SAID RIBBON SHIFTING LEVER; SAID PIVOT BEARING MEANS COMPRISING BEARING PINS ON OPPOSITE ENDS OF SAID PIVOT SELECTOR LEVER SELECTIVELY ENGAGEABLE IN THE ADJACENT APERTURE IN SAID RIBBON SHIFTING LEVER.

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