US2566944A

US2566944A - Typesetting means in record controlled printing machines

Info

Publication number: US2566944A
Application number: US774902A
Authority: US
Inventors: Last James
Original assignee: International Business Machines Corp
Current assignee: International Business Machines Corp
Priority date: 1946-09-19
Filing date: 1947-09-19
Publication date: 1951-09-04
Anticipated expiration: 1968-09-04
Also published as: GB671452A

Description

Sept. 4, 1951 J. LAST 2,565944 TYPESETTING MEANS IN RECORD CONTROLLED PRINTING MACHINES Filed Sept- 19. 1947 7 Sheets-Sheet l ATTORNEY 2,566,944 oLLED Sept. 4, 1951 J. LAST HPR-.smug MEANS 1N RECORD coNTR PRINTING MACHINES 7 Sheets-Sheet 2 Filed Sept. 19. 1947 INVENTOR .//Wff HS7- BY t ATToRNx-:ug

sept 4 1951 J. LAST v 2,566,9

TYPESETTING MEANS IN RECORD CONTROLLED PRINTING MACHINES A '7 Sheets-Sheet :5

Filed Sept. 19 1947 T LEQE.

BY QML a,

ATTORNEY Sept- 4, 1951 J. LAST 2566,

TYPESETTING MEANS 1N RECORD comoLLEn PRINTING MACHINES 7 Sheets-Sheet 4 Filed Sept. 19. 1947 [NNN S WJ m Nou. n w m mM. A

Sept. 4, 1951 Filed sept.' 19. 1947 J. LAST TYPESETTING MEANS IN RECORD CONTROLLED Y PRINTING MACHINES '7 Sheets-Sheet 5 INVENTOR .mm wr Sept. 4, 1951 J. LAST 2,566,944

IYPESE'ITING MEANS IN RECORD coN'rRoLLED PRINTING MACHINES Filed sept. 19. 1947 7 Sheets-Sheet 6 'INVENToR .///[S 1967" BY ATTORNEY Sept. 4, 1951 J. LAST 2,566,944

TYPESETTING MEANS IN RECORD CONTROLLED PRINTING MACHINES Filed Sept. 19. 19`47 '7 Sheets-Sheet 7 INVENTOR TTO R N EY Patented Sept. 4, 1 951 TYPESETTING MEANS IN RECORD coN- TRoLLED PRINTING MACHINES James Last, London, England, assigner to International Business Machines Corporation, New York, N. Y., a corporation ot New York Application September 19, 1947, Serial No. 774,902 In Great Britain September 19, 1946 11 Claims.

' l This invention relates to a print unit adapted to be used in accounting and the like machinery.

An object of this invention is to provide an improved print unit adapted for use in an accounting machine, the unit operating in response to timed impulses for printing any one of a full range of characters or symbols while maintaining the full speed of the machine.

Another object is to provide a printing mechanism in which the inertia and kinetic energy of its parts are minimized so as to prevent destructive wear at high speeds.

Still another object is to provide an improved mechanism for printing characters in close proximity to each other.

Yet another object is to provide a printing mechanism in which the blurring is minimized when a number of carbon copies are printed.

These desiderata involve the simplification of the mechanism for operating the type bearing member since a space equal only to the character width is available for the operating mechanism. The characters being made solid with the type bearing member lightens this member, but the number of characters sets the size of this moving part. The ability to deal with the carbon copies necessitates high speed hammer blows, together with high speed rebound.

In accordance with the present invention, therefore, the print unit has individual type bearing members, .the members being movable for the purposes of selecting a type. A positive coupling means is provided for each of the type bearing members, and a vpositive driving means common to all members is engageable selectively by each of the coupling means to initiate said selecting movement. There is also provided means for disengaging all of the coupling means from the driving means at a fixed instant in the cycle to termina'te said movement, and means individual to each member is actuated by a timed impulse for eiecting engagement of said coupling means with the driving means.

In the preferred form of the print unit, any one of the full number of characters possible with a given arrangement of timed impulses may be selected. It is preferred to employ an annular type bearing member which is positively driven to the approximate selected position, and then centered while free from the locating drive. A printing from a type element is effected by a light hammer acting through a metal strip, the paper and a carbon ribbon on the type face, the hammer being made to rebound under the action of a spring which threw it forward. The type bearing member is positively restored to its home position, 'and means are provided for stopping this member in its home position with but little shock.

It is an important feature of this invention that only one setting mechanism is provided and that this may be repeatedly operated under the control of successive impulses in one cycle.

One consequence of this is that all the single impulse selections result in characters being selected. whereas when second impulses are used only for the purpose of modifying a first impulse selection, four characters become available.

In the embodiment; shown, the impulses are electrical and are received by a group of magnets, one to each column. They might equally well. however, have been obtained from mechanical movements and delivered to members of the same nature as the magnet armatures illustrated.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings:

Fig. 1 is a section of a print unit, taken transversely of the print wheel axis.

Fig. 2 is a view of the left-hand end of the unit showing diagrammatically, the main gear trains and the main clutch but having the main cam unit removed.

Fig. 3 is a part front view showing part of the main cam unit, the magnet box and portions of the set lever assembly being removed.

Fig. 4 is a plan view with a middle portion omitted. l

Fig. 5 is a separate front elevational view of the main cam unit.

Fig. 6 is a separate right-hand side view of the main cam unit.

Fig. 7 is a view of part of the print unit as seen from the upper side of Fig. 4 and showing the sheet feed control.

Fig. 8 is a part section of the magnet box and set plungers taken on the plane 8-8 of Fig. l.

In the embodiment illustrated, each of a plura'lity of print wheels I'bears fty characters which are selected by timed electrical impulses derived from the electrical sensing of a card of the well known Hollerith type. As these cards have only 12 index points in eachlcolumn, the numbers 0 to 11 are selected by single impulses and the remainder |by two impulses variously 3 timed according to a code. It is a convention to refer to the 12 index points, in order of sensing, as 9 to 0, X, Y. 'I'he two hole combinations used in the code are 9 to X with Y, 9 to 0 with X, 9 to 1 with 0, 9 to 2 with 1, the total number of different selections being 12 (single hole) +11 +10 +9 +8=50, as stated above.

'Ihe type wheel I, illustrated, has 53 gear tooth spaces 2 separated by lands 69 and is angularly positioned by the rotaton of the set gear 3, the teeth 4 of which engage with the spaces.

Fifty of the lands between the spaces bear characters and three are blank. In its initial unset position, one ofthe blank lands 69 is at the printing line. The sequence of characters and blanks is as follows, two dots at half height indicating a blank:

It will be seen that between each pair of digits are four other characters, the doubledigits 10 and 11 being treated as special characters. Many other arrangements are possible to suit particular cases.

Where two impulses are employed to make a selection, the function of the second impulse is to modify the position of the type wheel which would be arrived at were the rst impulse/"used alone. Thus, impulses at 1, Y, O, or X times, respectively, when they are second impulses produce modifications of position to the extent of 1/5, W5, V5 or $3 of the pitch between successive digit positions.

Now referring to Fig. 1, there is one magnet 5 to each print wheel I. The arrangement of the magnets in plan is shown in Fig. 4 where it will be seen that they are in two rows in staggered relation. An impulse received by a magnet is synchronized with the arrival of the corner 6 of a groove 1 in the set cam 8, at the tooth 9 ofthe set lever I0. The set cam 8 controls the operating mechanisms for all of the print wheels I, and the operating mechanism for each of the print wheels includes a separate lever I0. The impulse withdraws the toe of the armature I2 from interference with the plunger I3 which is engaged with the lever I4 interlocked with the set lever I8. The set cam 8 makes one rotation per operating cycle in the direction shown by the arrow 65 and the timing of the impulse determines which groove 1 will be adjacent to the tooth 9 when it occurs. The set lever I0 is copivoted with the actuator 5, and the actuator latch IB pivoted on the actuator is retained engaged with the shoulder I1 on the set lever I0 by the spring I8. This spring causes the tooth 9 to enter the selected groove 1 and also to lower the rear end I9 of the actuator, so that the set latch 20 'pivoted on the clutch pawl 2| can engage the upper side of the end I9 by the action of the spring 22 and bell crank 23.

'I'he continued rotation of the set cam 8 discharges the tooth 9 from the groove 1 depressing the set lever I0 and through the latch I6 raising the end I9 of the actuator l5 together with the set latch 20. This disengages the clutch pawl 2| from the ring of the clutch 24. At the same time the depression of the set lever I8 lowers the lever I4 and the plunger I3 allowing the toelII of the amature I2 to reengage the upper end of the plunger I3 and so preventing further action of the set lever until another impulse ls received by the magnet 5. This magnet is the subject of my copending United States application Ser. No. 717,050, now Patent No. 2,493,885, patented January 10, 1950.

In the embodiment being described, the clutch 24 is of the type which is the subject of my copending United States application Ser. No. 614,486 and consists of a wheel member and a ring member. A spring tends to advance the ring member with respect to the wheel member through one tooth pitch. The clutch shown has 20 teeth and these are shortened by ten circular scallops which are formed in both clutch and ring members. When the clutch pawl 2| engages the ring and the check pawl 25 engages the wheel member, so as to retain the ring member retarded with respect to the wheel member, the scallops in both members coincide.

The drive gear 26 common to all columns runs continuously in the direction indicated by the arrow 21 at ten times the speed of the set cam 8. This ratio depends upon the number of zones employed in the setting code and is, in fact, twice the number of zones. Thus, a four zone code having three characters between successive digits requires the drive gear 26, when of 20 teeth as in the present case, to run at eight times the speed'of the set cam 8.

In the condition now referred t0, the drive gear 26 closely fits a scallop in the clutch but without touching it.

The disengagement of' the clutch pawl, as described, allows the clutch spring to rotate the ring member so that its scallop first bears on the top of a tooth of the drive gear 26 and then enters the following tooth space. The ring tooth continues to engage the following drive gear tooth, until the limit of its movement with respect to the wheel member is reached when it begins to rotate the wheel, the composite gear thus constituted by the clutch then being completely engaged with the drive gear 26.

The wheel member engages a coupler train,

one to each column, comprising the

wheels

28 and 29. The wheels 28 and 23 together with the clutches 24 are carried in a coupler frame 38 which is pivoted about the axis of the clutches 24. This arrangement allows the smaller gear 3|, which is integral with'the gear 28, to be engaged with or disengaged from the set gear 3. Engagement is effected in a manner to be described later, just before the leading corner 6 of the earliest groove 1 in the set cam 8 reaches the tooth 9 of a set lever I0 and is maintained until after the latest impulse time.

The discharge of the tooth 8 from a set cam groove 1, therefore, initiates the rotation of the set gear 3 and its related print wheel I.

The set latch 20 is retained lifted by its shoulder 32 which the spring 22 causes to engage the frame 33. In this position the upper arm 34 of the set latch 20 has its lip 35 in the path of a lip 36, 31, 38 or 39 on the knock-oil cam 40 which rotates continuously in the direction of the arrow 4| at equal speed with the set cam l.

supposing a single impulse only to have been received, the rotation of the print wheel will continue being positively driven through the clutch until the lip 36 on the knock-oil! cam 40 by engaging the lip 35 of the set latch 28 depresses the arm'34 and so disengages the latch 20 from the frame 33. This allows the spring 22 to reengage the clutch pawl 2| with the ring member of the clutch 24 and to arrest it with its scallop concentric with the drive gear 26. The rotation of the wheel member of the clutch 24 continues, restraining the clutch spring until the scallops of wheel and ring again coincide, the check pawl 26 preventing reverse movement of the wheel due to the clutch spring. In this condition the clutch is disengaged and the type wheel I is positioned in accordance with the timing of the impulse received by the magnet 5. It should be said that the lip 42 on the check pawl 25 engages the underside of the clutch pawl 2| just as the clutch pawl is about to release the ring, so that the completion of the clutch pawl movement outwards from the clutch 24 disengages the check pawl 25 from the clutch wheel to avoid trailing during the type wheel setting operation.

The lips 36, 31, 38 and 39 of the knock-oil cam 40 are related, respectively, to '1, nought, X and Y positions in a card column.

Similarly, the last four grooves 1 in the set cam 8 are related, respectively, to the 1, nought, X and Y positions.

It will be seen that the nought, X and Y grooves are of different widths. They all, however, have their leading corners 6 at the uniform pitch common to all the grooves. The fact is that, while the index points on the card pass at uniform intervals of time and the consequent releases of the set lever I0 to enter a groove are similarly timed, the ensuing disengagement of the clutch pawl 2i is timed by the passage of the following wall of the groove 1. Thus, the impulse is registered when it occurs but its effect may be delayed for some portion of an index point interval. This is done to differing extentsvin the case of the nought, X and Y impulses by giving different widths to their grooves 1 in the set cam 9. The following wall of each of these grooves is related to its particular lip of the knock-off cam 40. Thus, the starting of the type wheel train by the nought groove is terminated by the lip 31 of the knock-off cam 40, after the type wheel has moved 3/=, of a digit pitch. The movement started by the X groove is terminated by the lip 38 after the type wheel has moved of a digit pitch, and the movement started by the Y groove is terminated by the lip 39 after 2%-, of a digit pitch has been passed.

These movements, due to nought, X or Y impulses, take place independently of whether a previous impulse has been given, for the reason that the nought groove does not disengage the clutch pawl 2| until the lip 36 of the knock-off cam 40 has terminated a movement due to an earlier impulse.

This is also true of an impulse from the index point 1, provided it has not been preceded by an earlier impulse. When, however, the l impulse occurs as a second-impulse, the tooth 9 of the set lever ID enters the 1 groove in the set cam 8 while the clutch pawl 2| is still disengaged. This means that the link 43 pivoted to the lower clutch pawl arm is in its forward position and its foot 44 supports the tail 45 of the trailer 46 against rearward movement. At the time of the 1 impulse, the lip 41 of the delay cam 48 is passing the land 49 on the trailer 46, thereby preventing its forward movement so that the pivot of the trailer 45 on the actuator latch I 6 is prevented from moving forward when the tooth 9 of the set lever I0 enters the 1 groove. This causes the actuator latch I6 to be disengaged from the set lever I8, the immediately subsequent depression of which by the set cam 8 then failing to raise the rear end I9 of the actuator I5. The continued rotation of the delay cam 48 in the direction of the arrow 50 results in the lip 41 engaging the end 5I of the leg 52 of the actuator I5 and by displacing it to the rear, raising the end I9 at the same time reengaging the actuator latch I6 with the set lever I0. The position of the end 5I is such that this movement of the actuator occurs after the clutch pawl 2I has arrested the clutch 24, due to the action of the zero lip 36 on the knock-off cam 40, releasing the set latch 20. Thus, the set latch 20 is again lifted and the clutch 24 reengaged. This reengagement, due initially to a l impulse following an earlier impulse, occurs towards the end of the period in which a nought setting would be made, and the resulting movement of the type wheel is of the extent of 1/5 of a digit pitch, the lip 31 of the knock-off cam 40, which is responsible for terminating a nought setting, also serving to terminate this shorter setting due to a l impulse following an earlier impulse.

The disengagement of the actuator latch I6 in the manner just described is avoided, when the 1 impulse is not preceded by an earlier impulse, for then the impulse occurs when the link 43 has not been advanced, the clutch 24 being still held disengaged by the clutch pawl 2I. 'I'herefore, although the delay cam 48 engages the land 49 on the trailer 46, the tail 45 of the latter is. unsupported by the foot 44 of the link 43. Thetrailer 46 then swings idly when the tooth 9 on the set lever I0 enters the groove in the set cam 8, and the actuator I5 behaves as though integral with the set lever IIJ as in the case of earlier impulses, or the nought, X, or Y impulses.

After the point in the operating cycle at which a setting due to a Y impulse will have been com-- pleted, the coupler Wheels 3| are swung about the axis of the clutches 24 out of engagement with the set gears 3, and the aligner bail 53 is lowered, the springs 54 then causing the noses 55 of the aligners 56 to enter the adjacent gear spaces 2 in the type wheels I and rectify any small errors of alignment due to the gear train.

Attention is now drawn to the restoring shaft 51 about which the s-et gears 3 are pivoted. Each set gear 3 bears a projection 58, which is in the path of a restoring arm 59, one to each gear 3. and keyed to the shaft 51. Just in advance of the earliest and, therefore, the greatest setting movement, the shaft 51 is rotated in the setting direction indicated by the arrow 60 to bring its arms 59 to their furthest position shown chaindotted at 6I (Fig. 1). `This movement is performed at such a speed as will ensure the arms 59, always keeping ahead of the projections 58 on the gears 3 in their setting movement.

Immediately, the hammers 1I in the hammer unit 10 are released to cause printing on the sheet 80, the hammers being Withdrawn at once after impact.

The bail 53 is now raised to dis-engage thev aligners 56 from the type wheels I, and the shaft 51 is rotated to bring its arms back to the position 59 (Fig. 1). In this position, the projections 58 have been engaged by the arms 59, wherever they may have been positioned by setting movements, and brought to rest against the teeth of 7 the stop comb 82, thus restoring all type wheels to their initial positions with blank lands 68 at the printing line.

In a high speed mechanism such as is represented by the present embodiment, the restoring of members such as the type wheels and set gears 3 and the arrest of the restoring movement against a stop member, such as the comb 62, may give rise to destructive forces seriously limiting the effective life of the parts.

For this reason, the comb 62 is not a xed member but is pivoted about an axis 68 and has rocking movement about this axis during the restoring movement of the shaft 51. This rocking movement is such that the comb advances its teeth in a similar direction to the setting movement of the projections 58, but is retiring to its initial position at such a speed by the time the fastest moving projection 58 reaches it that no signicant shock is sustained by the moving parts. The final arrest of the comb and wheels thereafter takes place after a nite negative acceleration l positively controlled by which destruction of the parts by high impulsive loading, due to the sudden arrest of their masses, is avoided.

The type wheels I are of annular form and are individually pivoted upon and spaced by the disks |30, each of which is flanged to engage one side of its related type wheel. The disks |39 are centered upon the xed shaft |3| and are themselves spaced by the fixed combs |32 which rest upon the shaft and pass through slots |33 in the disks. The disks are prevented from rotation by the key |34. A felt strip |35 serves to convey lubricant.

The hammer unit 10 (Figs. 1, 2) is designed to deliver a rapid blow to the back of the paper followed by a prompt rebound to avoid blurring of carbon printing. There is a hammer 1| for each type wheel I, and each hammer has a small lever 12 pivoted to its rear end and bearing on an end face 13 of the hammer. This lever 12 has the spring 61 hooked to it. The hammers are withdrawn and their springs stretched by a lobe 14 of the rotary cam 15, which has three lobes and makes one-third of a rotation in each operating cycle in the direction of the arrow 66. The lobe 14 .bears on the shoulder 16 of each hammer, and its rotation is timed so that the lobe escapes the shoulders 16 at the instant when printing is required. The forward movement of the hammers under the pull of their springs 61 engages the levers 12 with the edge of a plate 11 shortly before the hammer heads 18 deliver their blow to the back of the sheet 80 through the steel strip 19. The plate 11 furnishes a fulcrum which results in a reversing impulse b ing applied to each hammer and causes rebound immediately after impact, the lever 12 rst pivoting on the plate 11 thereby swinging relatively away from the face 13 of the hammer and stretching the spring again. The relaxing of the spring after impact withdraws the hammer until the lever 12 again rests against the face 13. The plate 11 is adjustable edgeways of itself or in the direction of the hammer travel, to provide adjustment of the rebound distanceas well as of the force of impact.

This adjustment is obtained by sliding the plate 11 diagonally on the guides |89 (Fig. 4) and is effected through the graduated lever |90 on the shaft |9| pivoted on the end plate ||8 and having keyed to it the cam |92 which engages the roller |93 on a stud fixed in the plate 11. The steel strip 19 is use d to distribute the blow andto pre- 75 vent images of the hammer heads being produced on the sheet.

The hammer unit is supported directly from the underframe by the standards |85, |86 (Fig. 2).

The front standard |86 is pivoted on the underframe at |81. The rear standard is tog'- gle-jointed and, when the lever |88 is pushed to the rear, the entire unit is withdrawn from the printing line to allow free access for the insertion of multiple sheets and for other purposes, such as the mounting of a new ribbon.

'Ihe cam 15 (Figs. 1 and 2) has keyed to it a ratchet wheel ||0 (Fig. 2) having 6 teeth. The drive pawl is pivoted to the arm |02 which rocks freely about the axis of the cam 15. This arm is coupled by the link |03 to the rocker |04 which is pivoted on the underframe |08 and is driven through the link |05 and crank pin |06 in the gear |01, this gear making two rotations in each operating cycle. Thus, the ratchet wheel ||0 is advanced two teeth in each cycle, giving the necessary one-third rotation to the cam 15. The check pawl |09 serves to prevent reverse ro tation of the cam 15.

At the opposite end of the cam 15 (Figs. 4 and' 7) is keyed the three-lobed cam ||2 which coacts with the V-shaped lever ||3 pivoted on the stud |96 in the end plate ||8, the rollers ||4 bearing on the cam ||2. The lever ||3 has an arm ||5 which is linked to the arm ||6 freely pivoted about the fixed stud ||1 in the auxiliary plate |95. This stud also has freely pivoted on it the gear |20 which has keyed to it the ratchet wheel |2I. The gear |20 engages with the gears |22. |23 which are respectively keyed to the feed rolls 8|, 82. The arm ||6 has a pawl |24 which can engage the ratchet wheel |2|, when permitted to do so by the mask |25, the pawl |24 being wide enough to engage both the ratchet wheel and the rim of the mask. The mask |25 is angularly adjustable by the lever |26 which contains a spring-loaded plunger |21 bearing on the notched sector |28 formed on the auxiliary plate |95. Thus, the angular adjustment of the mask determines the point in the swing of the arm ||6 at which the pawl |24 will pass from the contour |29 of the mask |25 and engage the ratchet wheel |2|. The arrangement is proportioned so that a feed of one ratchet tooth pitch corresponds to an advance of the sheet 80 through the conventional single line spacing.

The sheet is held by the feed rolls 8|, 82 in conjunction with the pressure rolls 83, 84 (see,

Fig. 1). The pressure rolls 83, 84 are in short lengths, each length being trunnioned at its ends in a pair of brackets 85. 86. These brackets are.

pivoted on the bars 81, 88 and are bridged in pairs by the plates 89, 90, at the center of each of which a spring 9|, 92 is attached. The plates 89, 90 are stepped at their ends and rest freely in the slots 93, 94, in the

brackets

85, 86, thus dividing the spring load equally between the two ends of each

pressure roll

83, 84. A tooth .95, 96 on each4 vbracket is freely accommodated in a V groove in each release shaft 91, 98, when the

rolls

83, 84 are bearing on the sheet 80. Partial rotation of either release shaft 91, 98 by the levers 99, |00 will relieve the pressure of its associated pressure rolls 83 or 84.

In a print unit such asy the present, in which the characters are to be printed closely adjacent in a line, the support of the inking ribbon must be derived from its control at the ends of the line, intermediate guides being of little value. .The

9 method of feeding the ribbon is, therefore, involved and will now be described.

The inking ribbon 250 (Figs. l, 2, 4 and '1) is wound upon two spools 25|, 252, which are mounted upon

spindles

253, 254 journaled in the brackets 255, 256. A common rock shaft 251 also in Fig. 1) actuated by the arm 25B, link 259 and pin 260 extending from the rocker |04 serves to drive either spool as required, the rocker giving two strokes in each cycle as explained earlier with reference to the hammer unit. A common link 262 couples the drive reversing arrangements. Taking the spool 25|, the spindle 253 has keyed to it a flange 263 bearing a pin 265 for driving the spool. Beneath the bracket 255 is a ratchet wheel 261 also keyed to the spindle 253. Freely pivoted on a downward extension of the spindle is a mask lever 269, a reversing plate 303, and finally a drive lever 21 the fork 213 of which engages the conical stud 216 in the arm 218 which is keyed to the rock shaft 251, this connection being duplicated by the drive lever 212, and arm 211 also keyed to the other end of the rock shaft 251.

Thus, the two drive levers 21|, 212 are recipro- I cated at the same time.

Each drive lever 21|, 212 bears two

pawls

219, 280, 28|, 282. 'I'he pawl 219 is directed so as to engage the ratchet Wheel 261 and the pawl 28| similarly with respect to the ratchet -wheel 268. Both levers are shown at the beginning of their feed stroke, which is of an extent sufficient to feed the ratchet wheel through two tooth pitches, although it is not called upon to do so. The engagement of the drive pawls with their ratchet wheels is controlled by the reversing plates 303, 304. These plates are connected to each other rotationally by the reversing levers 283, 284, each engaging with a notch in its related reversing plate and being pivoted on the bracket 255 or 256. These levers are coupled at their front ends by the link 262. In the figures the pawl 219 is shown resting on its reversing plate 303, which has its notch 285 in such a position that the full stroke of the lever 21| will cause the ratchet wheel 261 to be rotated through one tooth pitch.

On the opposite side of the plate 303 the check pawl 281 pivoted to the bracket 255 prevents the ratchet wheel 261 from reverse movement. The reversing plate 303 has a second notch 289 which accommodates the nose of the check pawl 281 and allows it to vengage with the ratchet Wheel 261. The drive pawl 28| is resting on the reversing plate 304 which is in such an angular position as to prevent the pawl 28| from engaging with its ratchet wheel 268 throughout the whole of the stroke of the lever 212 to which the pawl is pivoted. Also, the plate 304' has. its check pawl notch 290 displaced from the check pawl 288 which is thus held disengaged from the ratchet wheel 266. The spool 252 is, therefore, rotated by the ribbon while this is being wound upon the spool 25|.

While the ribbon is being unwound from the spool 252, the tension lever 292 has its forward end resting in the deep notch 294 in the reversing plate 304. In this position the roller 296 on the rear end of the lever 292 presses the ribbon on to the fixed guide 298, thus maintaining tension on the ribbon between the guide 298 and the spool 25|. The other tension lever 29| has its forward end resting in the shallow notch 299 in the reversing plate 303, serving as a detent to retain the reversing plate system in its position. In this position the roller 295 on the lever 29| l0 is held off the ribbon as it passes over the fixed guide 291.

The continued unwinding oi' the ribbon from the spool 252 eventually causes the fork 214 on the mask lever 212 to be engaged by the usual eyelet or stud, adjacent to the ends of the ribbon, and to` be pulled towards the guide 298, thus rotating the mask leverI 210. This mask lever has a nose 302 which has hitherto been in the position shown, such that the reversing pawl 28| could not engage it. The rotation of the mask lever now advances the nose 302 until the pawl 28| can clear the nose and at the same time engage a notch 306 in the reversing plate 304. This is done at the end of the driveystroke of the lever 212, which is still made with the pawl 28| held out of engagement with the ratchet wheel 26B.

The return stroke of the lever 212 now causes the reversing pawl 28| to rotate the mask lever 210 and the reversing plate 304 until the forward end of the lever 292 rests in the shallow notch 300 in the plate 304, the lever 284, link 262 and lever 283 causing the rotation of the reversing plate 303 to such a position that the drive pawl 219 and check pawl 281 are heldout of engagement with the ratchet wheel 261, and the tension lever 29| brings its roller 295 to bear upon the ribbon as it passes over the fixed guide 291. The form of the reversing plate 304 is such that on the next driving stroke of the lever 212, the reversing pawl 28| in withdrawing from the notch 306 is displaced radially far enough to clear the nose 302 of the mask lever 210 and allow the spring 308 to restore the lever 210 to its former position. The two terminal mechanisms of the ribbon drive have now completely interchanged their functions and the interchange has been positively effected.

The foregoing explanation covers the essential functions of the unit. The provision for the relative timing of the movements will now be dealt with.

The timing of the various functions is performed by the cam unit 260 (Figs. 5 and 6) which is supported upon the studs 235, |55 in the sideplate |05 (Fig. 2), which enter the holes |98, |99 (Figs. 5 and 6). This unit has one cam shaft 20| and two rocker shafts 202, 203. The cam shaft is driven through the adjustable coupling 204 from the gear 26| (Fig. 2) which is driven by the clutch gear |54 and makes one rotation in each operating cycle. The cams are in pairs, one of each pair being complementary to the other in form. There are five pairs of cams and the two cams of each pair are separated by a distance piece which enables each rocker to enter the space between its two related cams, the two rollers on each rocker being on opposite sides of it. The left hand pair of cams 205. 206 controls the movement of the restoring shaft 51 (Figs. 1 and 2) through the sector rocker 201, the pinion 268, the shaft 209, and the angularly adjustable coupling 2|0 by which the shaft 209 is direct coupled to the shaft 51, the sector rocker 201 being freely pivoted on the shaft 203.

The cams 2| 2 |2 control the rocker 2|3, which is keyed to the shaft 203. This shaft provides a drive which may be used for an auxiliary purpose not related to the printunit proper and will not be referred to further. The cams 2I4, 2| 5 control the rocker 2|6 keyed to the shaft 202. This shaft bears at its end the adjustable arm 2|1 which engages the shaft 2|8 (Fig. 1) upon which the coupler gears 29 are pivoted. The shafts 2|8. 2|9 and 220 are incorporated in the coupler frame 30 and the three shafts are keyed to the frame 30, the lowest shaft 220 upon which are the clutches 24 being trunnioned in the side frames |05, |06. Thus, the rocking of the arm 2|1 (Figs. 5 and 6) effects the engagement and disengagement of the coupler gears 3| with the set gears 3 (Fig. 1) by rocking the coupler frame 30 about the axis of the shaft 220. The cams 22|, 222 control the rocker 223, which is freely pivoted on the shaft 202 and is linked to the auxiliary rock shaft 224 by the link 225. This shaft 224 is coupled by the adjustable coupling 226 to the stop comb 62 (Figs. 1 and 2), the purpose of which has already been described. The

cams

221, 228 control the rocker 229 also freely pivoted on the shaft 202. This rocker has a stud 230 which protrudes through a clearance hole 23| in the frame of the cam unit, and this stud is coupled by the link 232 (Fig. 3) to the end of the aligner bail 53, thus effecting its positive control by the

cams

221, 228.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a single modification, it will be understood that various omissionsand substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indi cated by the scope of the following claims.

What is claimed is:

1. A mechanism operable cyclically for printing characters in response to the sensing of holes at index points 9 to 0, X and Y in a column of a card comprising, in combination, a type bearing member, means supporting said member 'for movement so as to locate its type in printed positions, driving connections for said type bearing member, a continuously rotating driving means, said driving connections including coupling means adapted to be coupled to said driving means, means engageable successively with said index points in the order listed for sensing holes in said card, means operating in response to the sensing of a hole at any one of said index points for effecting engagement of said coupling. means to initiate movement of said member, means operating at a fixed time after the index point is sensed for disengaging said coupling if it has been previously engaged by the sensing of a hole at not more than one point, and means for disengaging said coupling after different time intervals if it is engaged due to the sensing of a hole at the 0, X or Y points. Y

2. The mechanism of claim 1 including means for making said means operating to disengage said coupling at a fixed time inoperative when a hole is sensed at the No. 1 point after sensing a hole at some previous point and effecting disengagement of said coupling at a later time.

3. 'I'he mechanism of claim 1 in which said means for effecting engagement of said coupling in response to the sensing of a hole comprises 'a rotating cam having notches adapted to receive a control element, said notches corresponding to said index points and each having a leading edge reaching a position to permit entry of said element in synchronism with the sensing of the corresponding index point, means for effecting movement of said element into a notch upon the sensing of a hole at the corresponding index point. said element being forced out of the notch by the trailing edge of the latter, and means actu'- ated by said element when the latter is forced out of a notch for engaging said coupling means with said driving means.

4. The mechanism of claim 1 in which said means for effecting engagement of said coupling in response to the sensing of a hole comprises a rotating cam having notchesv adapted to receive a control element, said notches corresponding to said index points and each having a leading edge reaching a position to permit entry of said element in synchronism with the sensing of the corresponding indexy point, the Width of said notches corresponding to index points 9 to 1 inclusive being equal while the width of said notches corresponding to index points 0, X and Y are different from each other and from the other notches, means for effecting movement of said element into a notch upon the sensing of a hole at the corresponding index point, said element being forced out of a notch by the trailing edge of the latter, and means actuated by said element when the latter is forced out of a notch for engaging said coupling means with said driving means.

5. The mechanism of claim 1 including means for connecting said driving connections in driving relation with said member' just before the sensing of said No. 9 index point and releasing said driving connections from said member after the sensing of the Y index point, means for centering and holding said member in its set position after said driving oonnecions are released, means for taking a print from said member while it is held by said last-mentioned means, and means for returning said member to its unset positions after operation of said print taking means.

6. A mechanism operable cyclically for printing characters in response to the sensing of holes at index points 9 to 0, X and Y in a column of a card comprising, in combination, a type bearing member supported for movement to selected printing positions, driving connections for said member, a continuously rotating driving means, said driving connections including coupling means adapted to be coupled to said driving means, means engageable successively with said index points in the order listed ior sensing holes in said card, means for connecting said driving connections in driving relation with said member during the sensing of said index points and disconnecting said driving connections after the last point has been sensed, means operating in response to the sensing of a hole at any one of said index points for effecting engagement of said coupling means to initiate movement of said member, the operation of said last-mentioned means taking place at fixed intervals after the sensing of holes at the 9 to 1 index points and taking place after different intervals on the sensing of holes at the 0, X and Y points, means operating at a fixed time after the 1 index .point is sensed for disengaging said coupling if it has been `previously engaged by the sensing of a hole at not more than one point, means for disengaging said coupling after different time intervals if it is engaged due to the sensing of a hole at the 0, X or Y points, means for centering and holding said member in its set position after said driving connections have been disconnected, means for taking a print from said member while it is being held. and means for returning said member to its unset position after a print has been taken.

7. The mechanism of claim 6 in which the means for effecting engagement of said coupling in response to the sensing of holes comprises a rotating cam having spaced notches adapted to receive a control element, said notches corresponding to said index points and each reaching a position to receive said element in synchronlsm with the sensing of the corresponding point, means for effecting movement of said element into a notch upon the sensing of a hole at the corresponding index point, said element being forced out of the notch by the trailing edge of the latter, means actuated by said element when it is forced out of a notch forv engaging said coupling, and means engageable at predetermined times with said last means if it is actuated by said element for effecting a release of said coupling.

8. The mechanism of claim 6 in which said last-mentioned means comprises a movable abutment for said member, means for moving said abutment at a decreasing speed in the direction in which said member is moved toward its unset position, said member engaging said abutment while its speed is being decreased so that said member is returned to its unset position without shock.

9. The mechanism of claim 6 in which said member carries digit printing type separated by type for printing dierent characters, and in which said means operating to engage and disengage said coupling means after the sensing of a hole at any one of said points effects a setting of said member to print a digit, while a sensing at a hole at the 9 to 1 points in combination with the sensing of a hole at one of the 1, 0, X and Y points effects a setting of said member to print one of said di'erent characters.

10. The mechanism of claim 6 in which said means for taking a print comprising a hammer, a metal tape, and means for actuating said hammer for striking said tape so as to force a paper against the type on said member.

11. The mechanism of claim 6 in which said means for taking a print comprises a hammer, and means including a spring for actuating said hammer to force a paper against the type on said member, said spring then operating to cause rebound of said hammer.

JAMES LAST.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,063,508 Keen Dec. 8, 1936 2,056,391 Daly Oct. 6, 1936 2,076,713 Ford Apr. 13, 1937 2,157,035 Torkelson May 2, 1939 2,199,561 Fuller May 7, 1940 2,227,143 Knutsen Dec. 31, 1943 2,381,862 Beattie Aug. 14, 1945 2,386,422 Beattie Oct. 9, 1945 2,438,071 Page Mar. 16, 1948