US2063508A - Printing mechanism - Google Patents

Description

Dec. 8, 1936. H. H. KEEN I PRINTING MECHANISM Filed Oct. 4, 1955 4 Sheets-Sheet l A'i'TORNEY 7 a a I:

will/11111111111)!!! H. H. KEEN PRINTING MECHANISM Filed QGhv 4, 1935 a I INVENTOR Ai'TORNEY 4 Sheets-Sheet 2 Dec. 8, 1936. H. H. KEEN 2,063,508

PRINTING MECHANISM INVENTOR ATTORNEY Dec. g, 1936. H. H. KEEN 2,063,508

PRINTING MECHANISM Filed Oct. 4, 1935 4 Sheets-Sheet 4 RPM ymww i; BY

A'TToRNEY Patented Dec. 8, 1936 UNITED STATES PATENT OFFICE PRINTING MECHANISM York Application October 4, 1935, Serial No. 43,538 In Great Britain October 23, 1934 5 Claim.

This invention relates to printing mechanism arranged for control by record cards of the kind in which each column is divided'into two parts and tin which some 01' the characters which are to be printed are represented each by a single hole in the column and others are represented by pairs of holes, one hole being in one part oi the column and the other hole in the other part of the column in accordance with a code. Each column may be conveniently divided into a main part comprising ten hole positions and a subordinate part comprising two hole positions, so that any one of thirty-two characters can be represented in a column.

For convenience it will be assumed that the characters are represented on the card by holes punched therein, but the present invention is also applicable to printing mechanism in which the characters are represented by marks made on the card in selected positions and which are read by light-sensitive devices in a known manner. V I

More specifically the present invention relates to printing mechanism of the kind comprising two. controlling members which are reciprocated and which are each arrested, as they move from a home position, in a position determined by the position of a hole in an associated part of a column of the card. Thetwo controlling members are arrested by means controlled by a card-reading device and jointly determine the position of a setting member in accordance with the positions in which they are arrested. The setting member serves to position a type-carrier which is provided with type for printing the various characters. One of the controlling members operates to make a coarse adjustment of the setting member and, therefore, of the typecarrier, while the other operates to efiect a fine adjustment by moving the setting member relatively to the first controlling member through one or more units of movement which are smaller than the units of movement imparted to the setting member by the first controlling member.

It has been proposed to provide means for locking the setting member to the first controlling member in any one of a number of positions and to employ the second controlling member to determine the position in which the setting member will be locked to the first controlling member, the setting member moving with the first controlling member when the latter is adjusted. It has also been proposed to connect the two controlling members to the setting member by differential gearing so that they jointly t mine the position of the setting member. Hitherto in mechanism of this kind, the typecarrier has been secured to the setting member. Owing to the large number of type to be accommodated on the type-carrier, the latter has to be of relatively large dimensions and to have a relatively large stroke. The stroke and dimensions of the setting member will be correspondingly large and the stroke of the first controlling member will be at least as large. it the controlling members are connected to the setting member by differential gearing the stroke of the first controlling member will be larger than that of the setting member.

It is desirable to keep the strokes of the various parts of the mechanism as short as possible and also the dimensions of the parts, which are partly dependent on their stroke, as small as possible, in order to reduce the inertia eilfects and allow of the mechanism being operated at a high speed. Further any reduction in the dimensions of the parts is advantageous since it tends towards a compact structure. It will be obvious that the stroke of the type-carrier cannot be reduced since it is determined by the number of type it carries, but it is the object of the present invention to provide printing mechanism of the above kind wherein the stroke and dimensions of the various parts, other than the type-carrier, are reduced as compared with prior mechanism of this kind.

The present invention provides printing mechanism of the above kind wherein the setting member is connected to the type-carrier by movement-increasing gearing so that the stroke of the setting member is less than that of the type-carrier and the controlling members have correspondingly reduced strokes.

Preferably, the two controlling members are connected to the setting member by difierential mechanism which may comprise a differential lever fulcrumed on the two controlling members or parts moved thereby and having the setting member pivoted on it.

Conveniently the type-carrier is in the form of a wheel to which a pinion is secured and this pinion meshes with-teeth formed on the setting member which is mounted to reciprocate substantially in a straight line.

With the arrangement according to this invention, any error in the adjustment of the setting member is magnified in the adjustment of the type-carrier. It is accordingly another object of the present invention to provide the type-carrier with a set of teeth and to provide a justifying 55 element movable after the type-carrier has been set to engage between a pair of teeth and accurately position the type-carrier.

The printing mechanism according to the present invention may be employed in combination with the printing mechanism adapted to print numerals only and of the known kind comprising a plurality of reciprocating type-bars and means for differentially arresting them under the control of a record card. According to this feature of the invention the first controlling members are designed to have substantially the same stroke as the type-bars of the numeral printing mechanism and common means is provided for reciprocating the first controlling members and the numeral printing type-bars.

Printing mechanism embodying the above and other features of the present invention will now be described with reference to the accompanying drawings in which:-

Figure 1 is a cross-section through the printing mechanism showing the parts in their normal home position,

Figin'eZisasimiIarsectiQntoFigure lbut shows the parts in the position occupied at the moment of printing,

Figure 3 shows atically driving mechanism for the printing mechanism,

Figure 4 is a simplified circuit diagram for the printing mechanism, and

Figures 5 and 6 illustrate the manner in which printing is effected.

Like reference characters indicate like parts in all the figures of the drawings.

Alphabetical and numerial printing mechanism according to the present invention will be described as applied to a record-card-controlled statistical machine of the well-known Hollerith kind such as that shown in U. S. patent to C. D. Lake et al. #1,976,61'7 dated October 9, 1934. The printing mechanism is provided in addition to the usual printing mechanism which prints numerals only. Since the construction and operation of this kind of statistical machine and of the numeral printing mechanism provided in it are well-known, they will not be described herein.

Referring to Figure 3, the machine is provided with a list shaft l0 (corresponding to list shaft I65 in the above mentioned patent) on which a list cam II is rotatably mounted. This cam can be coupled to the shaft III by a one-revolution clutch of conventional construction so that this cam operates whenever the clutch is engaged. The clutch is engaged in any cycle of the machine, in which the printing mechanism is to operate, in a well-known manner which need not be described. A gear-wheel I2 is secured to the cam H and drives a gear-wheel l3 secured to a shaft l4. This shaft, through bevel gearing l5, drives a shaft l6 which through bevel gearing drives a shaft IS. The shaft I8 thus rotates at such times as the cam H is rotating and serves, as will be explained hereinafter, to operate the alphabetical section of the printing mechanism in conjunction with the cam The cam through a suitable lever not shown, reciprocates a cross-head 20 on guides 2| which are mounted in fixed frame members 22. A plurality of first controlling racks 23 are supported in the cross-head 20. The lower ends of these racks are guided in slots in a cross-bar 24 and the upper ends in slots in the upper frame member 2!. Lugs 25 on the lower end of the racks 23 are held against the cross-member 24 by levers It which are pivoted in a bracket 21 and are pulled upwardly by springs 28. Thus, as the cross-head rises, the racks 23 will also rise. Each of the racks can be arrested in any position, as it rises, by energizing a rear print magnet RPM. when energized, this magnet rocks a latch II to unlatch a pawl 30 which engages one of ten teeth 3| on the rack. The rack is then held while the cross-head continues its upward movement, the springs 28 stretching to permit this.

The cross-head II also carries a plurality of type-bars in the numeral section of the printing mechanism. These type-bars are of conventional construction and are similar to the racks 23 except that they are extended upwardly to the level of a platen 32. Each type-bar carries a type-head at its upper end. The type-bars are arrested in the same way as the controlling racks 13 by pawls 30 which are released when the print magnets are energized. As this printing mechanism is well-known it need not be described in detail. Suitable mechanism, not shown, is provided for relatching the pawls l0 behind the latches 2! when the cross-head 2| moves downwards towards its home position. As this mechanism is well-known and has no part in the present invention, it will not be described.

The shaft l8 rotates whenever the cam rotates and the printing mechanism is in operation, as previously explained. This shaft carries a pair of complementary cams 33 and 34 which rock a double-armed lever 35 secured on a shaft 36. A pair of levers I! are secured on the shaft It and engage, at their upper ends, a cross-head 38. The cross-head a is supported on guide rods 38 which, in turn, are carried by frame members 40. The timing is such that the levers 35 and 31 and the cross-head 38 remain stationary during the first part of the upward movement of the cross-head 20. During approximately the last third of the upward movement of the cross-head 20, the levers 35 and 31 are rocked counter-clockwise and move the crosshead 38 to the left into the position shown in Figure 2. The two cross-heads are restored simultaneously from the position shown in Figure 2 to that shown in Figure 1.

A plurality of second controlling racks 4| are supported at one end in slots formed in a member 42 which forms part of the cross-head 4|. At their other ends the racks 4| are supported in slots formed in a fixed frame member 43. The racks 4| are pressed to the left so that lugs 44 on them engage the member 42 by levers 45. These levers are pivoted in a bracket 46 and pulled to the left by springs 41. The racks 4| will thus move with the cross-head 38 to the left but can be individually arrested, the springs 41 yielding so that the cross-head can continue its movement without the racks.

Each of the racks 4| can be arrested in either of two positions by energizing anassociated front print magnet FPM which then rocks a latch 48 to release a pawl 49. This pawl engages one or other of two teeth labelled X and Y in Figure 1, depending on the time when the magnet was energized. The pawl 49 is relatched by a high tooth 50 when the cross-head 38 moves back into the position shown in Figure 1.

If one of the magnets FPM is not energized, the corresponding rack 4| moves to the left until it engages an adjustable stop 5| as shown in Figure 2. The second controlling rack 4| can thus be arrested in any one of three positions as it moves to the left. If one of the magnets aooauoa RPM is not energized, the associated rack 23 moves until engaged by an adjustable stop 52. Each rack 23 can thus be arrested in any one of ten positions by energizing its magnet RPM at the appropriate time and in an eleventh position, if this magnet is not energized.

The standard Hollerith record-card has twelve hole positions in a column. The hole positions are designated Y, X, 0, 1 8 and 9, reading from top-to bottom. Each column may be regarded upper part comprising the X and Y" positions and the lower part the "0 to 9 positions. I Each of the magnets RPM is energized at a time determined by the position of a hole in the lower part of a column while the corresponding magnet FPM is energized in accordance with the position of a hole in the upper part of the column.

The numerals and the letters of the alphabet are represented by holes in accordance with the following code:-

-o12a4cc7eo xanc'nar'nrxnm r znroa'ruvwxr 0123456789 13 to M if there is a hole in. one of the 0 to "9 positions, as shown in the top line of the above table. In the same way, a hole in the "Y position represents one of the letters in the second line in accordance with the position of the hole in the lower part of the column.

Referring again to Figure 1, each pair of first and second controlling racks 23 and 4| controls the position of a setting rack 53. This rack is pivoted at 54 on a differential lever 55 which is fulcrumed at I55 on ling rack 23. The lever 55 carries a pin 56 which rides in a slot 51 in a lever 58 which is pivoted at 59. The associated second rack 4| carries a pin 55 which engages a slot 5| in a lever 52.

This lever is also pivoted at 59 and is adjustably secured at 53 to the associated lever 58.

, The rack 53 is provided with teeth 54 which mesh with a pinion 55 secured to a type-wheel 53. Each pinion 55 and. the associated typewheel 55 rotate on an individual bushing 51 which is non-rotatably supported on a bar 55. The type-wheel 551s provided with thirty-three type round one half of its periphery. The type are arranged in the order shown in the above table, starting at A and reading down each column in turn. Thus the type reads A, Z, B, N, 0, etc., the A type being to the left of the wheel as seen in Figure 1. As the first controlling rack 23 rises, the differential lever 55 rocks about its pivot 55 and raises the setting rack 53 which rotates the type-wheel 55. The arrangement is such that a movement of the rack 23 equal to the pitch of the teeth 3| turns the wheel 55 to carry three of the type past a platen.

as being divided into two parts, the

the associated first controlally,

| a Each of the teeth 3| correspondsto one of the digits 0 to 9 and when the rack 23 is arrested by the pawl 30 engaging one of the teeth 3|, the corresponding type-wheel 55 will be arrested in a position determined by the position in which the rack was arrested. Since each tooth 3| corresponds to a digit it also corresponds to one of the type on the wheel 55. The arrangement is such that when the rack 23 is arrested, by the pawl 30 engaging a particular tooth 3|, say the 5" tooth, the wheel 55 is positioned with the type for printing the next lower digit, for example, in the case suggested, the 4" type, approximately opposite the platen 32.-

Concurrently with the latter part of the movement of the cross-head 20, the second controlling racks 4| are moved to the left until arrested by the pawls 49 or by the stops 5|. As each rack moves, it rocks the composite lever 53, 52 and rocks the differential lever 55 about its pivot I55 on the associated rack 23. As the lever 55 rocks about its pivot I55 it draws the setting rack 53 downwardly. The rack 53 then rotates the associated type-wheel 55 backwardly. The arrangement is such that if a rack 4| moves its full stroke to the left, it will rotate the wheel 55 through approximately three type spaces. Since each rack 4| can be arrested in any one of three positions, it can rotate the associated wheel 55 backwardly through one, two or three type spaces so as to bring opposite the platen 32 one of the three type immediately following, in a clockwise direction, the type which was positioned opposite the platen 32 by the associated first controlling rack 23.

Each first controlling rack 23 thus efiects a coarse adjustment of the associated type-wheel 55 while the corresponding second controlling rack 4| effects a fine adjustment by turning the wheel backwardly one, two or three steps.

Assuming that the slot 51 is horizontal the pivot 54 would move vertically with equal steps as the rack 23 moved up with equal steps. The pivot 54 would also move first to the left and then to the right along a curved path, as the lever 55 turns about its pivot i56. Since the pivot 54 is to the right of the vertical through the point at which the rack 53 meshes with the pinion, the movement of the pivot 54 to the left will accelerate the clockwise rotational movement imparted to the wheel 55 by the setting rack 53 and movement of the pivot 54 to the right will decelerate the movement of the wheel.

There is thus a tendency for the ratio between the speeds of the rack 23 and wheel 53 to decrease as the rack rises. This tendency is overcome by the fact that the slot 51 is normally inclined as shown in Figure 1. As the pivot 55 moves to the left, the pin 55 moves to the left down the slot 51 and is depressed proportiondecelerating the movement imparted to the wheel. When the pivot 54 and the pin 55 move to the right, the pin is raised by the slot and the movement of the wheel is accelerated. The slope of the slot is selected to provide approximately the required compensation.

A similar effect occurs when the lever 55, 52 rocks, but here movement of the pin 55 to the left in the slot 51 occurs when the movement given to the wheel 55 is decreased and to the right when the movement is increased. The slot 51 is non-radial with respect to the pivot 59 of the arm 55, so that movement of the pin 55 to the left increases the movement imparted to the lever 55 and hence to the wheel 55, while movement to the right decreases the movement imparted to the wheel.

The shaft 68 is supported in a frame comprising a pair of arms 18 pivoted at II and connected together at their upper ends by a bar I2. The frame is held against adjustable stops I8 by springs I4. Each of the setting racks 53 is held against its pinion 65 by an individual spring-loaded plunger 15, the plunger I5 being carried in a suitable spring-box I6 which is secured to the bar I2. After all the wheels 66 have been positioned, the frame 18, I2 is rocked about its pivot II by a pair of cam elements II which are secured on wheels I8 and which engage projections 18 on the arms I8 as shown in Figure 2.

The wheels are thus pressed against a suitable ink ribbon which makes an impression on paper passing around the platen 32. The bushes 61 are free to slide on flats formed on the shaft 58 to a limited extent. Normally the spring plungers I5 operate to maintain the bushes 61 and shafts 68 in the relative position shown in Figure 1. When, however, the wheels 66 are moved to the left to make an impression, they are arrested as soon as they engage the platen 32 while the shaft 68 moves further to the left into the position shown in Figure 2. The pressure for effecting printing is supplied by the springplungers 15 acting through the setting racks 53 .and the pinions 65. This arrangement is provided to prevent risk of the type being damaged during the actual printing operation. The rack 53 and pinion 65 provide a movement-increasing gearing so that the total linear movement of any type on the wheel 66 is greater than the total movement of the rack 53. Consequently, any error in the setting of the rack 53 will result in a magnified error in the setting of the wheel 66. In order to correct any such errors, justifying mechanism is provided for aligning the type wheels 66.

Each of the type wheels is provided, round one half of its periphery, with teeth 88, the gaps 8i between the teeth being each diametrically opposite one of the type. Justifying elements 82 are pivoted on a rod 83 and co-operate each with one of the type wheels 66. The rod 83 is supported by two plates 84 which are pivoted by means of adjustable eccentric pivots 85, one on each of the arms I8. The two plates are secured together by a cross-member 86 and tails 81 of the elements 82 are held against this cross-member by springs 88.

An arm 89 is secured to the assembly 84, 86

and a spring 88 is connected to this arm at one end and to one of the arms 18 at the other end. This spring rocks the assembly 84, 86 counterclockwise so that an abutment 8| secured on the assembly engages an adjustable stop 82. The stop 82 is adjusted so that teeth 93 on top of the justifying elements 82 are just clear of the teeth 88 on the wheels 66.

After the wheels 66 have immediately before the cam elements 11 engage and rock the arms 18 to effect printing, a pin 84 secured on a wheel I 84 engages a cam surface 85 and rocks the assembly 84, 86 clockwise about the pivots 85. The justifying elements 82 will thus rock together so that the teeth 33 enter gaps 8| opposite them. The arrangement is such that the upper side of each tooth 93 tends to engage the underside of the tooth 88 which happens to be immediately above it (see Figure 5). After this engagement has taken place, the

been positioned and corresponding element 82 rocks about its pivot 88 while the assembly 84. 86 continues its movement.

After this has occurred, the arms I8 are rocked about the pivots II. As the arms I8 rock each setting rack 58 will also rock about its pivot 54. During this movement the rack 58 rises relatively to the pinion 65 and rotates the latter and the wheel 66 clockwise. During this clockwise movement of the wheel the element 82 is rocked by its spring 88 clockwise and its tooth 88 enters fully into the gap between two of the teeth 88. It will be noted that the upper surface of the teeth 88 is substantially radial to the wheel 66 so that the tooth will, by prevent further rotation of the wheel 66.

The clockwise movement of the wheel 66 which is a consequence of the arrangement shown is thus made use of to ensure that the tooth 88 shall be properly seated in one of the gaps between the teeth 88. If, after the wheel 66 has been finally located, there is any tendency for it still to rotate clcckwise, this is taken care of by a slight downward movement of the rack 28.

The shaft I8, through gearing 86 and 81, drives a vertical shaft 88 which, through gearing 88, drives a shaft 188. This shaft operates known hammer-actuating mechanism for the numerical section of the printing mechanism. This hammer-actuating mechanism need not be described. The shaft I I8, through gearing I8I, drives a gear-wheel I82 which is rotatable on a shaft I83. The gear-wheel I82 can be coupled to the shaft I83 by a one-revolution clutch I84 net PCM. The shaft I83 engaging the surface, A

and m of the alphabetical section. It will be recalled that these wheels bring about the actual printing by the type-wheels 66. The magnet PCM is energized atthe proper time in each cycle in which alphabetical printing is required in any suitable manner, not shown herein. In such cycles as the printing mechanism is re-- quired to operate without the alphabetical section printing, no circuit is completed through the magnet PCM so that the clutch I84 remains disengaged and the shaft I83 is not driven. Thus, the magnet PCM would not be energized dur-' ing a total printing cyc Referring now to Figure 4, there will now be described the manner in which the magnets RPM and FPM are energized under the control of the cards. Each card is fed downwardly from a magazine, first past a row of upper brushes U3 and then, one cycle later, past a row of lower brushes LB. For this purpose card feeding mechanism of conventional construction is employed such as shown in the previously mentioned U. S. patent. At the moment when the X holes in a card are passing the upper brushes, cam contacts II8 close so that if there is an X" hole in the card a circuit will be completed through the upper brush reading the column containing that hole, normally closed contacts IIIa, one winding X of a double-wound relay, the contacts H8 and upper card lever contacts UCL which are closed in a known manner as long as a card is passing the upper brushes. The relay X is thus energized and closes its contacts XI so as to complete a circuit extending through its holding winding Xh and cam contacts II2. These contacts remain closed until the zero holes on the same card pass the lower brushes. The relay winding. Xh thus remains aoeaaoe energized for the same periodv and holds contacts X2 closed until the same time.

When the rack ll (Figure 1) has moved'sumciently to the left to bring its tooth X opposite the nose of the pawl 49, cam contacts H3 close to complete a circuit through the print magnet FPM, the contacts X2 and the contacts H3. The magnet FPM then arrests the type-bar in the "1! position. This occurs while the card in question is passing the lower brushes.

As the card passes the lower brushes, a circuit iscompleted through the lowermost hole in the column in; question, the corresponding lower brush and the magnet RPM. If there is a hole in one of the positions f0 to 9 the magnet RPM will be energized and will arrest the associated rack 23 in its corresponding position. If there is no hole in one of these two positions, the rack will move until arrested by the stop 52. Thus, by the zero time in the cycle in which the card passes the lower brushes, both the racks will have been positioned.

If there is no X hole in a particular column, the circuit previously traced through the upper brushes and the relay winding X will not be completed. Immediately after the "1! holes tacts Illa are opened and contacts lllb are closed, connecting relay coils Y to the upper brushes. As the "Y" holes pass the upper brushes, cam contacts H8 close so that if there is a "Y" hole in the particular column in question, a circuit will be completed through this hole, the appropriate upper brush, the contacts lllb; the relay coil Y, the cam contacts 5 and the contacts UCL. The coil Y closes its contacts Yl to energize a holding coil Yh and also closes contacts Y2. The coil Yh is held energized by the contacts H2 until the zero time in the next cycle. When the Y" tooth on the rack is opposite the nose of the pawl 49 (Figure 1), cam contacts H6 close to energize the magnet FPM through the contacts Y2. The rack ll will thus be arrested in the Y position.

If there is neither an "X" nor a "Y" hole in a particular column, no circuits will be completed through the upper brush reading that column and the magnet FPM will not be energized. The rack M will then move to the position shown in Figure 2.

At the end of a cycle cam contacts ill close to energize a relatching coil 8. The contacts Illa and lllb are normally latched with the contacts llla closed. The function of the coil III is to unlatch them at the appropriate time so that they reverse their condition. The coil H8 operates to relatch them in their normal condition.

Assume that the column of .a card has a single hole in the 9 position. When this card passes the upper brushes no circuit is completed through the upper brush reading the column in question. When the card passes the lower brushes, a circuit is completed through the hole and the magnet RPM so that the pawl 30 (Figure 1) engages the uppermost tooth in the rack 23. Initially the type-wheels are positioned with the gap between the M and Y type opposite the platen. The slight upward movement of the rack 23 rotates the type-wheel until the 8 type is approximately opposite the platen. Towards the end of the cycle the cross head. 38

(Figure 1) moves to the left and the particular rack ll in question moves until arrested by the step ii. This willresult in the type wheel being rotated through slightly more than three type spaces 'so as to bring the "9 type just above the printing line, as shown in Figure 5. The justifying elements 82 are then rocked and the tooth 93 on one of them engages in the gap 8| opposite the 9" tooth. The arms I0 are then the type-wheel through slightly more than one type space so as to bring the "M type lust above the printing line. During the printing movement of the type-wheels this type would have been accurately positioned. In the same way, a "Y and a 9 hole result in the "Y" type being brought to the printing position.

When the type bar 23 is arrested in the position shown in Figure 2 as the result of there being a zero hole in the card, the operation is similar except that the rack 23 will still be rising when the rack 4| moves to the left. Thus,'for ashort time the movement of the type-wheel will be the result of the joint movement of the two racks.

If there is no hole in one of the positions "0? to "9 the rack 23 rises to its highest position and either the type A" or the type Z or the type will be selected for printing in accordance with the position in which the rack ll is arrested. The type is selected if both the racks move to their full strokes. This type is provided since the type wheel will move until some part of it engages the platen, and serves to prevent an impression being made from the top and bottom of the two adjacent types. The result of providing this type is that the words printed will be separated by full-stops and. all blank spaces in a line of letters will be fllled in with dots;

While there has been shown and described and pointed out the fundamental novel features of the invention as applied to a single modification it will be understood thatvarious omissions and 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 indicated by the scope of the following claims.

What is claimed is:

1. In a printing machine, a pair of type setting bars, means for adjusting said bars, a bell crank operated by one of said bars, a difljerential link with one end pivoted on the other of said bars and at the other end connected to said bell crank, a rack pivoted on said link and moved a distance which is the resultant of the combined movement of the bars, a type carrier operated by said rack, a. platen, and means for impressing the type against the platen.

2. In a printing machine, a pair of type setting bars, means for adjusting said bars differentially, a bell crank one end of which is pivotally connected to one of said bars, a differential link carrying a fulcrum stud, said link being pivoted at one end on the other of said bars and at the other end carrying a pin fitting in a slot in said bell crank, said slot being normally inclined to compensate for the arcuate movement of said stud, a rack pivoted on said stud, a type carrier operated by said rack, and means for printing from said type carrier on record material.

3. In an alphabet printing machine, a digit bar adjusted diiferentially according to a digit entry, a zoning bar adjusted diiferentially according to one of three possible zoning entries, a link with connections to both bars so that at one end it is lifted by the digit bar and at the other end it is lifted by the zoning bar, a type carrier with a series of spaced type, a rack for setting said carrier in a position to print from a selected one 01' said type, said rack being operated by said link and pivoted thereon near the connection to the digit bar so that one step of movement of the digit bar causes three type spaces of movement on the carrier, and each step of movement of the zoning bar causes a movement oi. a single type space on the carrier, and means for printing from the type carrier on record material.

4. In a printing machine controlled by record cards, a pair of type setting bars, means under control of the cards for setting said bars, a differential link with connections to said bars so arranged that one end of the link is moved by one bar and the other end of the link is moved by the other bar, a type carrier, a rack for moving said type carrier to printing p sition, said rack being connected to said link to be moved by the combined action 01' both bars, and means for printing from said type carrier on record material,

5. In an alphabet printing machine controlled by record cards perforated with regular digit perforations and special zoning perforations, a digit bar, means under control of the digit perforations for adjusting said digit bar, a zoning bar, means under control of said zoning perforations for adjusting said zoning bar, a differential link with connections to said bars so that each end is moved by one of said bars, a type carrier with aseries of type, a carrier operating rack pivoted on said link at such a point that one step of movement caused by the digit bar moves the carrier through a number of type spaces greater by one than the number of type space movements caused by adjustment of said zoning bar, and means for printing from said type carrier on record material.

HAROLD HALL KEEN.

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