US2911472A - Type positioning mechanism of telegraph printing apparatus - Google Patents

Description

'Nov. 3, 1959 R. G. GRIFFITH 2,911,472

TYPE POSITIONING MECHANISM OF TELEGRAPH PRINTING APPARATUS Filed April 29, 1955 4 SheetS -Sheet 1 EEEEEEEEiEEEEEEEE A EEEEEEEE=EEEEEEEE EEEEEEEEEEEEEEEE Attorney Nov. 3, 1959 R. G. GRIFFITH 2,911,472

TYPE POSITIONING MECHANISM 0R TELEGRAPH PRINTING APPARATUS Filed April 29, 1955 4 Sheets-Sheet 2 2/ 52% 79 55 7a 73 7/ 77 (W l/ 7574/7/02 E/ A a M Attorney 'NOV. 3, 1959 GRIFFITH 2,911,472

TYPE POSITIONING MECHANISM OF TELEGRAPH PRINTING APPARATUS Filed April 29, 1955 4 Sheets-Sheet 3 Inventor WM MW WVL w. M

Attorney Nov. 3, 1959 R. G. GRIFFITH TYPE POSITIONING MECHANISM OF TELEGRAPH PRINTING APPARATUS Filed April 29, 1955 4 Sheets-Sheet 4 I nventor Attorney a total of sixteen spaces.

TYPE POSITIONING MECHANISM on Turn- GRAPH PRINTING APPARATUS Application April 29, 1955, Serial No. 504,852

,This invention relates to aggregate motion type posi- Ronald George Grifiith, Mount Royal, Montreal, Canada the characteristics of the five unit code and since this is standard, the space I will always come in the same place. Thus when case shifting from the upper case to the lower case area, the maximum movement required in a horizontal direction is eightspaces, i.e. from the sixteenth to the eighth. After case shifting, 'when the next letter signal is received, the maximum movement is seven spaces, i.e. from the eighth space to the first.

When case shifting, however, from the lower case area to the upper case area, the operative space, which is shown as f. is fifteenth from the right in the bottom row and this is again dictated by the standard fiveunit code.

. Thus whenever a figure shift signal is received, either tioninig mechanisms of the kind employedin printing telegraph apparatus or operating under the control of signal recording mechanisms to place the selected type'i'n the printing position and described, for example, in British patent specification' No. 441,090. Printing telegraphapparatus using a type carrier positioned by an aggregate motion mechanism operating under the control of a signal recording mechanism, which is used to record 'the well-known five unit code, has to be provided with what is generally known as ,case shifting mechanism. The reason for this is thatthere are only thirty-two different combinations ofthe five units of the code, and thirty-two different type positions does not give sufficient space to accommodate-both an alphabet of twenty-six letters, together with figures and various other necessary symbols. Consequently the type on the type carrier is divided into twoseparate areas each containing thirty-two different spaces; One area contains all the letters and is referred to as the lower case area,

while the other area contains all the figures and symbols and is referred to as the upper case area. When the type when the type carrier is operating in the lower case area, or inadvertently when it is operating in the upper case area, the space 1 is moved to the printing position, Consequently the maximum horizontal movement which may be involved is tom the first space to the fifteenth space, which is a total of fourteen spaces, and "is nearly double the movement which is involved when case shifting from the upper case area to the lower case areai Moreover if the figure shift signal has been given inerror and is immediately followed by aletter shift signal, the type carrier first moves fourteen spaces to the right and then moves back seven spaces to the left. The large movement of fourtee'nspaces is objectionable mainly because it limits the speed at which this kind of type positioning mechanism can be successfully operated but it is inevit able because the position of the space 1 is situated in the half of its case area remote from the other area,

.. ,}unlike the face I which lies in the half of its area nearer carrier is operating, for example, in the lower case area,

all signals received serve to move one of the thirty-two spaces in this area into the printing position. If one of the thirty-two spaces in the upper case area'is required, then a separate case shifting operation is required which brings. about a major bodily change of the typecarrier as a whole. i

The situation can best be described by reference to Figure 1 of the accompanying drawings, which shows the standard arrangement of type faces on a type carrier. These are arranged .in four vertical rows each containing The lower case area is constituted b'y1t'he right-hand half of the type carrier and includes four rows each of eight spaces. Similarly the upper case area is constituted by 'the left-hand half of the type carrier. In order to produce a .case shifting operation, the case shifting mechanism must be energised in response to a particular combination of the five units of the code, but in addition to operating the case shift ing mecihanism, this particular combination will also automatically serve to position a particular space in the printing position, although'this space will not be occupied by a type face.

The combination required to produce a shift from the upper case area to the lower case area, and which may be referred to for convenience as a letter shift signal, corresponds to the eighth space from the right in the bottom row indicated as '1. Consequently if. the type head is operating in the upper case area and a letter shift signal is received, the type head will be moved to bring the space I into the printing position. Similarly if the type head is operating in the lower case area and a letter shift signal is inadvertently given, the space I will be brought to the printing position, although in thiscase no type shifting, operation will be brought about.

the first area.

It will be realized that the relative positions or the two locations f and I cannot be freely adjusted, but,

on the contrary, are restricted by the characteristics of the five unit code. According to the present invention, the shift from the lower case areato the upper case area is delayed so that instead of occurring in the cycle in which it is recorded, it occurs in the subsequent cycle. Consequently when the type carrieris operating in the lower case'area and a figure shift signal is received, the only immediate action is to transfer a space 1 to the printing position. This space flis the seventh from the right in the bottom row and is thes'pace in the lower case area corresponding to the space 1 in the upper case area. In this way the maximum horizontal movement which isbrought about is from the first space to the seventh space in the bottom row, that is to say, a movement of six spaces. When the next signal character is received, the case shift occurs simultaneously with the movement ofthe selected space in the uppercase area to the, printing position. In other words, if the next signal characterv corresponds to the space g the case shifting movement is carried out simultane'ously with the movement of the space gto the print? ingfposition. gives a maximum horizontal movemerit of from the seventh space to the sixteenth space,

which is a horizontal distance of nine spaces, and thus I movement and the two cancel one another out so that no resultant movement is obtained. This represents a of a reciprocating bail so that the subsequent motion of the pawl member produces the case shift during the same cycle of operation. The necessary delay in the figure shifting movement is then produced by arranging that the setting of the code permutation members allows a second pawl member to move into the path of the bail and the subsequent motion of this second pawl serves to cock the mechanism which is not released until the subsequent cycle to produce the case shifting movement.

Mechanism in accordance with the invention will now be described in more detail by Way of example with reference to Figures 2 to of the accompanying drawings, in which:

Figure 2 is a'diagrammatic perspective view of the operating mechanism, including aggregate motion mecha nism and the type carrier;

Figure 3 is "a portion of Figure 2 to an enlarged scale;

Figure 4 is a diagrammatic view of the case shifting mechanism; and

Figure 5 is a timing diagram showing the relationship between the operation of different parts of the mechanism, the horizontal co-ordinate representing time in milliseconds from the start of a cycle and the vertical co-ordinate representing the movement of the different parts'to an arbitrary scale.

Referring first to Figure 2, code permutation members stantly driven shaft which turns in a clockwise direction as seen in the figure. A number of ratchet wheels R1 to R5 and R15 are fixed to this shaft so as to turn with it, each ratchet wheel being situated adjacent the corresponding gearwheel so as to co-operate with the corresponding pawl 21. Thus when a code permutation member is in the space position and its extension is rocked by the cradle 8, its heel portion engages the space release detent to rock it in a counter-clockwise direction about its pivot 16 and thus to move the lip out of engagement with the arm 20a. This allows the pawl to turn in a clockwise direction under the action of the spring 23 so that it engages the continuously turning ratchet wheel and thus effectively clutches together the ratchet wheel and the corresponding gearwheel. The gearwheel then makes a half revolution until the arm 20a is engaged by the upper portion of the corresponding mark detent, which again rocks the pawl back against the effect of the spring so as to disengage it from the ratchet wheel in the position shown in connection with thegearwheel G5. Thus when a space releasedetent is rocked, the corresponding gearwheel makes half a revo lution until the pawl is again held off by the mark re- 1 lease detent, and it will be understood that, when in this position, the mark release detent is rocked, the gearwheel will make 'a further half revolution until it is again held up by the space release detent.

'Meshing with each gearwheel in a 1:1 ratio is a series of crank gearwheels CG1 to CGS and CG15, each turning'on a stud 30. Each crank gearwheel has a crank pin 31 which carries one end of a connecting link 32, the other end ofwhich is connected to a bellcrank lever.

All the bellcrank levers are mounted to turn freely on a 1, 2, 3, 4 and 5 are controlled by means of signal selecting mechanism, not shown, which acts by way of pivoted vanes V1 to V5. Thus according to the angular position of each vane, the corresponding code permutation member is moved longitudinally between a space position, which is the left-hand of the two positions shown in the drawing, and a mark position, which is the right-hand position. Each member is provided with a pivoted extension E1 to E5 formed with an opening 6 through which passes the cross member 7 of a cradle 8 pivoted at 9. The openings '6 are elongated so as to allow for the longitudinal movement'of the permutation members andtheir extensions. 1 f

The cradle 8 is provided with a control arm 10 cooperating with a cam 11 which once per )cycle of operation rocks the cradle 8 to lift the extensions and rock them about their pivots. In addition to the five code permutation members, there is a further member 15, provided for case shifting, and controlled by a vane V15 to be described in more detail later. The member 15 can also movefbetween two longitudinal members, and has an extension E15, which is rocked by the cradle 8, in the same manner as the other extensions. At its further end, each'ofthesix extensions has an upturned heel portion H1 toHSa'nd H15, which, when the cradle 8 is rocked, co-operates either with a space release detent S1 to S5 and S15 or with a mark release detent M1 to M5 and M15. As seen in Figure 3 the space release detents are each pivoted at 16 and the mark release detents are pivoted at 17, the twobeing pulled together against stops 18 and 19 respectively by means of a tension spring 20. Each space release detent is formed at its upper end with an inturned lip L1 to L5 and L15. In its unoperated position each lip co-operates with a transverse arm 20a formed on a pawl member 21 pivoted at 22 to one of a series of gearwheels G1 to G5 and G15. Each .pawl is acted on by a spring 23 attached at its other end to the gearwheel and the action of the lip on the space release detent is to rock the pawl about its pivot 22 against the'action of the spring into contactwith a stop 24.

The gearwheels are mounted to turn freely on a con-l common shaft 33. Thus as a gearwheel makes a half revolution, its associated crank gearwheel also makes a corresponding half revolution and the associated bellcrank lever is rocked. During the next half revolution, the pair of gearwheels return to their original positions, and the bellcrank lever is also rocked back to its initial position.

The bellcrank levers rocked by the crank gearwheels 'CG3, CG4, C and CG15 constitute part of an aggregate motion mechanism indicated generally at 34.

Thus the crank gearwheel CG3 rocks one arm 40 of a bellcrank lever, of which the other arm 41 is provided with a pin 42 acting in a fork 43 on a further bellcrank lever 44. The crank gearwheel CG4 rocks one arm 45 of a bellcrank lever, of which the other arm 46 carries the pivot 47 of the lever 44. In this way the rocking movements of both'arms 41 and 46 are added together in the motion of the bellcrank lever 44.

' At its other end the bellcrank lever 44 is provided with a fork 48 co-operating with a pin 49 mounted on the upper end of a further bellcrank lever 50. This is pivotediat 51- on one arm 52 of another bellcrank lever, of which the other arm 53 is rocked by the crank gearwheel CGS so that the movement of the lever 50 aggregates the motions of the crank gearwheels CG3, CG4 and C65. At its lower end the lever 50 has a fork 55 co-operating with a pin 56 on the lower end of a further bellcrank lever 57, which in its turn is pivoted at 58 to one arm 59 of a bellcrank lever, of which the other arm 60 is rocked by the crank gearwheel CG15. Thus the motion of the upper end of the lever 57 aggregates the motion of all four crank gearwheels. This motion is transmitted to a toothed rack 64 pivoted at 65 to the upper end of the lever 57 and supported by a stop member 66 so that as the lever 57 rocks, the rack 64 is given a longitudinal movement.

The ratios of the various lever arms are so selected that if a half revolution of the gearwheel G3 is considered as giving the rack unit motion, then a half revolution of the, gearwheel G4 will give two units of motion, a half revolution of the gearwheel G5 will give four units of motion and a half revolution of the gearwheel G15 will give eight units of motion. If the movement is from a space release detent to a mark release detent, then the motion produced will be in one direction and if it is from a mark release detent to a space release detent, then it will be in the opposite direction. Thus it will be understood that for any particular combination of settings of the members 3, 4, 5 and 15, there will be acorresponding position of the toothed rack 64. There will in fact be sixteen such combinations and this will lead to sixteen different positions of the rack.

Movements of the rack 64 are transmitted to a toothed wheel 70 mounted on a spindle 71, on the other end of which is a further toothed wheel 72 meshing with a third wheel 73. The toothed wheel 73 is mountedon a shaft 74 formed with a spline, or keyway 75 on which slides a gearwheel 76 formed with spiral teeth. The wheel 76 has a small key 77 co-operating with the keyway 75 so that although the wheel can slide on the shaft 74, it cannot turn.

The spiral gear 76 meshes with a gear sector 78 also provided with spiral teeth and turning about a vertical axis on a splined shaft 79. A mounting 82 for a type head, indicated generally at 83, is provided with a key 85 co-operating with a keyway 85 on the shaft 79 so that the mounting is free to slide but not to turn on the shaft. Consequently longitudinal movements of the rack 64 aretransmitted via the spindle 71, shaft 74 and the shaft 79 to the mounting 82 and hence to the type head itself 83. Thus for .each of the sixteen longitudinal positions of the rack 64. there is a corresponding angular position of the type head 83. 1

The type head is provided with four horizontal rows of type members, each row containing sixteen type members so that each of the sixteen angular positions of the type head brings one of the members in a row into the printing position. I

Thus it will be seen that the angularjposition of the type head is controlled in accordance with the positions of the members E3, E4, E5 and E15. The twomembers E1 and E2 control a; further aggregate motion mechanism indicated generally at 90 which in itsturn controls the vertical movements of the type head 83. For this purpose the crank gearwheel CG1 rocks one arm 91 of a bellcrank lever turning on the shaft 33 and of which the other arm 92 is connected through a pin and fork connection to one arm 93 of a further bellcrank lever. This further bellcrank lever is pivoted at 94 toa bellcrank lever 95, which is rocked by the crank gearwheel CGZ. so that the; movement of the arm 96 of thebellcrank lever aggregates the motions of the crankgearwheels CG1 and CGZ. The proportions of the levers are such that a half revolution of the crank gearwheel CG1 produces double the displacement produced by a half revolution of the crank gearwheel C62. 5 In this way the four combinations of the different positions of the members E1 and E2 lead to four different positions of the bellcrank arm 96.

The arm 96 is connected by a pin and fork connection 97 to a cradle 98 pivoted at 99. The crosspiece 100 of this cradle extends across the width of the machine and thus controls the movements of a forked lever 101 turning about a fixed pivot 102. The opposite end of the lever 101 is pivoted to a stud 103 on the mounting 82 for the type head 83. Thus rocking movements of the cradle 98 are transmitted to the lever 101 and serve to raise and lower the mounting 82 on the splined shaft 79. In other words, each of the four positions of the aggregate motion mechanism produces a corresponding vertical position of the type head 83 and serves to bring one of the rows of type membersup to the printing level.

As previously mentioned, the member 15 is provided for case shifting purpose and this operation is described in more detail with reference to Figure 4. A letter shift selector member 300 is pivoted on a spindle 301 and ooof the code notches of the member registers with its corresponding vane. Consequently the member drops, being assisted in this movement by a spring 302 which acts between a letter shift selector pawl 303 and its support lever 304. This lever is pulled in a clockwise direction against a stop 305 by means of a spring 306. At its other end, the pawl is formed with a cross-piece 307 which rests on top of the selector member 300 so that the pawl 303 presses down on the member 300 and drops with the latter when the vanes V1 to V5 are all in the mark position.

In this lower position, the pawl tooth 308 at the end 'of'pawl 303 is in a position where it can be engaged by an operating bail 309. The bail is pivoted at each end at 310 and is operated by an arm 311 provided with a follower 312 cooperating with a cam3l5. This cam 315 is mounted on a cam shaft 314 and serves to rock the bail 309 in a counterclockwise direction against the effect of a spring 316 once per cycle of operation in a time relationship shown by diagram F of Figure 5. Also Operating on the same pivots 31. 0 is a lift cradle 317 provided with an arm 318 cooperating with a cam 319 mounted on the operating cam shaft 146. This cradle is rocked against the effect of a spring 320 and serves to lift the member 300 in a time relationship as shown by diagram E of Figure 5.

When the selector member 300 is moved to its low- 7 est position as previously mentioned, the pawl tooth operates with the vanes V1 to V5 in such a way that 308 is in a position to be engaged by the bail 309, and

the selector pawl 303 is moved to the left so that its support lever 304- moves in a counterclockwise direction on its pivot 325. At the same time a bellcrank lever 326 pivoted to the pawl 303 at 327 engages the vane V15, turning it in a counterclockwise direction against-the effect of a spring 328. The bellcrank lever 326 is spring-loaded by means of a spring 329 so that when the vaneVlS reaches the'limit of its travel, the bellcrank lever yields and stretches. the spring 329. Under normal conditions, clockwise movement of the bellcrank lever under the effect of the spring 329 is limited by the abutmentof a turned-over end portion 330-with the top of the member 300. 1

Following the completion of the operating movement of the bail 309, the cradle 317 lifts the member 300' to disengage the pawl tooth 308 from the bail 309, after which the pawl 303 returns to its normal position under the control of the spring 302. In the meantime, however, the vane V15 has been locked in its counterclockwise position by means of a letter shift locking pawl 335,

which is pivoted to the spindle 301 and is formed with a slotted end 336 for engaging the vane V15. The move ment of the vane V15 to its counterclockwise or letter shift position occurs approximately half way through the lifting operating of the cradle 317, and consequently the member 15, shown inv FigureZ, is positioned for cooperation at a time before the operation of the cam 11 so that when the cradle 3 is operated, the letter shift operation of the gearwheel G15is brought about, provided, of course, it was previously in the figure shift position. same angle or cycle in which the letter shift signal is recorded. a 7

When the vanes V1 to V5 move to the figure shift .code setting, a figure shift selector member 338, also pivoted on the spindle 301, is allowed to fall. This movement is assisted by pressure from a figure shift pawl 339, which is formed with a cross-piece 340 in the same manner as the pawl 303 and presses on the top of selector member 338. The figure shift pawl 339 is pivoted at 341 to a supporting lever 342 pivoted to the spindle 325 and it is urged in a counterclockwise direction about its pivot 341 by a spring 343. The supporting lever itself 342 is pulled in a clockwise direction about the spindle 325;.a-gainst a stop 344 by means of a spring 34-5. When the member 338 andv its associated pawl 339 drop, -the in other words, this operation occurs during the' 'pawlwtooth 346 on the end of the pawl 339-movesinto positionfor engagement by the bail 309 and operation of the bail causes the pawl to be moved to the left, thus rocking the support lever 342 about the spindle 325. The only effect of this motion is that a transverse end portion 352 of a trip pawl 350 pivoted at 351 to the pawl 339 rides over the face of a detent 353 forming part of the letter shift locking pawl 335, and then, under the control of a spring 354, the trip pawl 350'turns in a clockwise direction so that its transverse end portion 352 drops down to the left of a shoulder 355 on the detent353. Nothing further happens until, on the return stroke of the bail 309, the pawl 339 moves to the right carrying with it the trip pawl 350. This presses against the shoulder 355 on the detent 353 and rocks the letter shift locking pawl 335 in a clockwise direction about the spindle 30 1, thus raising its slotted end 336 to free the vane V15 and to allow it to return to its clockwise or figure shift position under the control of the spring 328. Vane V15 returns to its biased position after cam 11 has operated, so that the figure shift operation does not take effect until the cycle after that in which the shift signal is recorded with all the advantages previously mentioned. Pawl 335 normally is urged in an anti-clockwise direction by spring 335a.

The different operative movements of the type carrier may thus be summarised as follows. While the type carrier is operating within the lower case area, each signal received serves to move the corresponding letter type face to the printing position. If a letter shift signal is inadvertently received, this moves the space I to the printing position. If a figure shift signal is received, the initial effect is to move the space f1 to the printing position during the cycle in which the signal is received. During the following cycle the case shifting movement is produced and simultaneously the required figure or symbol is moved to the printing position. If, however, the figure shift signal has been inadvertent and is followed by a letter shift signal, then these two cancel one another out and no movement is produced so that the space 1 remains in the printing position.

When the type head is operating in the upper case area, each signal received will serve to move the appropriate figure or symbol type face to the printing position. If inadvertently a figure shift signal is received, space f is moved to the printing position. If a letter shift signal is received, then the space l in the lower case area is moved to the printing position during its cycle of recordal. As previously mentioned, however, this will involve a movement of at the most eight spaces in a horizontal direction.

In order to complete the description of the relationship between the ditferent parts of the mechanism, the different diagrams constituting Figure 5 will now 'be referred to briefly. Diagram A shows the operation of the cam 140 referred to in copending application Ser. No. 504,851, filed Apr. 29, 1955. Diagram B shows the operation of the trip for the operating cam shaft which carriesthe earn 147 of the aforesaid application, and

whose operation is shown in diagram C. Diagram D shows the operation of the permutation transfer cam. Diagrams E and F have already been referred to and show the operation of the cams 319 and 315.

Diagram G shows the operation of the cam 11 of Figure 2. Diagram H shows the operation of the cam 161 described in copending application Ser. No. 504,851, filed Apr. 29, 1955. Diagram I shows the operation of the gear-wheels G1 to G5 and G15 of Figure 2, and diagrams K and L' show the operation respectively of a print trip cam shaft and a printing cam shaft described in detail in copending application Ser. No. 504,853, filed Apr. 29, 1955. I claim:

1. In telegraph printing apparatus, the combination of a platen, a type carn'er mounted to traverse said platen,

said carrier having a plurality of type locations in an upper-case area and a plurality of type locations in a lower-case area adjacent said upper-case area, type faces mounted in certain of said locations in each case area, aggregate motion mechanism controlled by received signals and connected to move said carrier to bring a selected type face into a printing position opposite said platen, case-shifting means for shifting said carrier to operate in one or the other case areas, first control means responsive to a first case-shifting signal received during one operating cycle and connected to effect operation of said case-shifting means in one direction during the same operating cycle, second control means responsive to a second case-shifting signal during one operating cycle and connected to effect operation of said case-shifting means in the opposite direction during the next succeeding operating cycle, and means responsive to a first case-shifting signal received during said subsequent cycle and operating to prevent operation of said case-shifting means during said subsequent cycle.

2. A combination according to claim 1 said carrier having four rows of type locations in both case areas.

3. A combination according to claim 2, each of said rows having sixteen type locations.

4. A combination according to claim 1, said type faces being in parallel rows lying on a part-cylindrical surface having an axis perpendicular to said parallel rows, said aggregate motion mechanism acting to move said carrier in a direction parallel to said axis to select .a row of type faces and to turn said carrier about said axis to select a type face in the selected row.

i 5. A combination according to claim 1 wherein said first'control means eifects operation of said case-shifting means to bring into printing position a type location lying within said lower-case area, and said second control means operates to bring into printing position a type location lying within said upper case area.

6. A combination according to claim 5 wherein one type location within one area lies adjacent the other area, and the other type location in said other area is remotely positioned from said one area.

7. In telegraph printing apparatus, the combination of permutation means responsive to received signals, first and second control means controlled by said permutation means and operating on receipt of first and second case-shifting signals respectively, delay means operated by said second control means, case-shifting means controlled by said first and second control means and being moved in one direction by said first control means and in another direction by said delay means, and a movable type carrier connected to be shifted by said case-shifting means, said type carrier having type faces some of which are arranged in an upper case area and others of which are arranged in an adjacent lower case area, said type carrier being shifted by said case shifting means to operate in one or the other case area depending on the direction of movement of said case-shifting means, said delay means operating to delay operation of said case-shifting means from the cycle of receipt of said second caseshifting signal until the subsequent cycle, and means controlled by operation of said first control means in the said subsequent cycle to over-ride said delay means.

l .8. In telegraph printing apparatus, the combination of permutation means responsive to received signals, first and second pawl members controlled by said permutation means and moving, on receipt of first and second caseshifting signals respectively, from an inactive into an active position, a bail arranged adjacent said pawl members, means to reciprocate said bail during the cycle of receipt of a signal and to engage and move, during the said cycle, a pawl member if and only if the pawl member is in a position to engage said bail, delay means operated by movement of said second pawl member but operating only in the cycle subsequent to the said cycle, caseshifting means controlled by said pawl members and being moved in one direction by movement of said first pawl member and released for movement in the opposite direction by the operating of said delay means, resilient means urging said case-shifting means in said opposite direction, and a movable type carrier connected to be shifted by said case-shifting means, said type carrier having type faces some of which are arranged in an upper case area and others of which are arranged in an adjacent lower case area, said type carrier being shifted by said case-shifting meansto operate in one or the other case area depending on the direction of movement of said case-shifting means.

9. In telegraph printing apparatus, the combination of a type carrier having a plurality of type locations in an upper-case area and a plurality'of type locations in a lower-case area adjacent said upper-case area, type faces mounted in certain of said locations in each case area, means mounting said carrier for movement to bring any type location into a common printing position, case-shifting means having a two-position control member for shifting said carrier to operate in one or the other case into lower-case position during the same operating cycle,

second control means responsive to an upper-case shift signal received during one print-ing cycle for pre-setting a tripping pawl for said latch, and means operative during the next succeeding printing cycle for operating said tripping pawl.

References Cited in the file of this patent UNITED STATES PATENTS Long Sept. 14, 1943 Salmon Sept. 19, 1944 Durkee June 15, 1954

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