US3340800A

US3340800A - Dual roller platens in address printing machines

Info

Publication number: US3340800A
Application number: US547114A
Authority: US
Inventors: John H Gruver; Lyle W Seifried; Dean W Johnson
Original assignee: Multigraphics Inc
Current assignee: AB Dick Co
Priority date: 1966-03-21
Filing date: 1966-03-21
Publication date: 1967-09-12
Anticipated expiration: 1984-09-12

Description

- J. H. GRUVER ETAL Sept. 12, 1967 DUAL ROLLER PLATENS IN ADDRESS PRINTING MACHINES '7 Sheets-Sheet 1 Original Filed April 25, 1963 INVENTORS v Jo/ n M Gruver 1' 0 Se D w: W5,

- ATTORNE).

Sept. 12, 1967 J. H. GRUVER ETAL 3,340,800

7 Sheets-Sheet 3 Original Filed April 25, 1963 3mm 17M ATTORNEY J. H. GRUVER ETAL 3,340,800

Sept. 12, 1967 DUAL ROLLER PLATENS IN ADDRESS PRINTING MACHINES Original Filed April 25, 1963 '7 Sheets-Sheet /45 349 (1,4, H-Gruvm [7/2 INVENTORS f. AQW

ATTORNEK ep 12. 1967 J. H. GRUVER ETAL 3,349,800

DUAL ROLLER PLATENS IN ADDRESS PRINTING MACHINES '7 Sheets-Sheet Original Filed April 25, 1963 Sept. 12, 1967 Y J. H. GRUVER ETAL ,8

DUAL ROLLER PLATENS IN ADDRESS PRINTING MACHINES Original Filed April 25, 1965 Sheets-Sheet 6 Fig.

" fl JMPRESS/ON m/(manowPzAm/ 343' Arm/m5 x p IMPRESSm/V TAKEN EYS/IORTPMTE'A/ 343 p 1967 D J. H. GRUVER ETALD 3,340,300

DUAL ROLLER PLJX'IIE114S 1N ADDRESS PRINTING MACHINES Original Filed April 25, 1963 7 Sheets-Sheet '7 INVENTORS John Gfuver, LYLE WSelfn d 4' e K W202? AT TORNEK United States Patent 12 Claims. (Cl. 101-56) This invention relates to a method of printing and to printing machines, and more particularly to platen mechanisms for use therein.

This application is a continuation of application Ser. No. 275,608, filed Apr. 25, 1963 (now abandoned).

In printing machines of the character through which small plates or printing devices are sequentially passed and in which machines the platen mechanism of the present invention is particularly useful, the platen mechanism functions to effect printing operations from the respective printing devices in a series thereof passed sequentially and in a step-by-step manner through the machine. One or more printing impressions may be made from each of the printing devices, the platen mechanism being operated through the printing or impression forming cycle each time such a printing impression is to be made.

The plates or printing devices from which the printing impressions are formed in such machines may take many different forms, but in most instances each printing device carries a plurality of lines of printing characters such as embossed type from which printing impressions may be made upon a document by means of a ribbon of transfer material lying between the printing device and the document.

A printing machine of the general kind here referred to is illustrated in US. Patent No. 2,359,849. In the ma chine disclosed in that patent, the platen is arranged to have a printing motion such that it rolls away from the operator in a direction which is usually parallel to the shorter dimension of the printing devices used, but in any event is perpendicular to the direction in which the lines of type on the printing device extend, thereby printing all of the characters on a single line at one time. This is beneficial from the standpoint of allowing the platen to have the shortest stroke possible and thereby contributes to the end of achieving maximum machine speed.

It has, however, been determined that the quality of impression obtainable with the prior machine falls slightly short of the requirements which certain special applications inherently demand. One example of such special application is the making of impressions in accordance with American Bankers Association specifications for E-13B magnetic code printing where the result is required to be sensed automatically with a stated degree of accuracy. Such impressions are of course, made with a transfer element of the carbon paper type rather than the more usual ink impregnated cloth ribbon. Even then, apparently, when the printing device is prepared by embossing sheet metal or sheet plastic, it seems to be impractical to secure characters such that a printing pressure value sufliciently constant over all areas of each individual character can be achieved when the printing operation is conducted using the prior printing machine and platen.

It is accordingly an object of the present invention to provide a method and machine capable of using embossed sheet material printing elements, and taking an impression therefrom in a way such that improved character reproduction can be secured.

In particular it is also an object of the invention to provide a method and machine capable of taking impressions 3,340,800 Patented Sept. 12, 1967 from printing devices of sheet material with the characters thereon formed by embossing, in which the characters include E-13B type, and which impressions are of sufficiently high quality to meet current American Bankers Association specifications.

According to the present invention, it has been found possible to improve the impression from an embossed printing element by power driving a platen roller parallel to the lines of characters on a printing device to take an impression therefrom, and particularly to so construct the equipment that a single one of several adjacent lines of characters only can be embraced in the printing operation.

It is also an object of the invention to provide a method and arrangement whereby various portions of a printing legend on a printing device may be selected individually for printing by a platen motion along the lines of type on the printing device.

Still another object of the invention is the provision of a roller platen mechanism capable of operating by a rolling action along the lines of type on an embossed printing device, which mechanism is compatible with the basic machine drive and frame of previous powered roller platen address printing machines.

Still another object of the present invention is the provi sion of a roller platen printing machine capable of automatically taking an impression from one zone of a printing device on a first pass, and alternately taking an impression from a second zone of the printing device on a second pass, and repeating such a cycle with each successive printing device.

A further object of the invention is the provision of a roller platen printing machine wherein the platen may be selectively set for automatic alternation in accordance with the foregoing object, or for continuous operation taking successive impressions from the same zone of a printing device at every cycle.

A still further object of the invention is the provision of a method and device for taking impressions where plural separate platen passes are required toprovide a complete impression, but wherein ribbon consumption is not excessive, even though ribbon feeding action may be mechanically tied to the platen cycle.

An additional object of the invention is the provision of a simple effective throwout mechanism related to a bell crank in the platen drive linkage for protecting the equipment and the operator in case an extraordinary load is imposed on the drive for any reason during a printing cycle.

Other objects, features and advantages will appear hereinafter as the description proceeds.

In the drawing:

FIG. 1 is left side elevation of the upper portion of a printing machine showing the platen supporting and moving equipment of the device of the present invention;

FIG. 2 is a front elevation to a larger scale showing the platen supporting and moving equipment of FIG. 1',

FIG. 3 is a top plan of the device shown in FIG. 1 with a portion of the platen support arm brokenaway to show the parts more clearly;

FIG. 3a is a detail plan similar to a portion of FIG. 3, but showing the platen drive linkage in throw-out position;

FIG. 4 is a section taken substantially on line 4-4 of FIG. 3, but drawn to a larger scale;

FIG. 5 is a detail section of the platen shaft taken substantially on line 55 of FIG. 2;

FIG. 6 is detail elevation partly in section, taken generally from the direction of FIG. 5, but illustrating an alternate form of platen;

FIG. 7 is a section taken substantially on line 77 of FIG. 4;

FIG. 8 is a section similar to FIG. 7, but showing the parts in printing position;-

FIGS. 9 and 10 are detail sections taken respectively substantially on lines 99 and 1010 of FIG. 4, with platen frame members omitted for clarity;

FIGS. 11 and 12 are detail sections corresponding respectively to FIGS. 9 and 10, but showing the parts in printing position;

FIG. 13 is a detail section taken substantially on line 13-13 of FIG. 3, but drawn to a larger scale and showing the automatic platen shift mechanism in operative position; 7

FIG. 14 is a detail section similar to FIG. 13, but showing the automatic platen shift mechanism in inoperative position;

FIG. 15' is a face view of a printing device of the type designed for use with the machine of the invention in one of its forms; and

FIG. 16 is diagrammatic plan showing the relationship of certain impressions to the carbon ribbon used with the device of the invention.

General Referring to the drawing the printing machine of the present invention includes a desk-like frame (not shown) which comprises a table-top T from which projects upwardly and then parallel thereto the upper section or stamper arm S of a generally C-shaped printing frame F, the lower arm of which (not shown) is structurally associated in a known manner with a printing anvil A (FIG. 2) which lies just beneath an opening in the tabletop T. The machine, as with previous devices of this nature, is designed to progress embossed printing devices D (FIG. 2) along tracks with a stepping motion to bring each of the devices D in turn into printing position above the anvil A. Referring to FIG. 3, the direction of this motion of the device D is generally from top to bottom of the figure (that is, from the back of the machine towards the front thereof) with the character lines on each device D extending from left to right.

In order to take impressions from the device D on anvil A, the distal end of stamper arm S supports a platen mechanism P which comprises elements which can be brought into rolling pressure contact with the back surface of a document overlying the printing device D. As seen in FIG. 2, the platen mechanism P is supported beneath the stamper arm by adjustable support means 1 7, 19 of a known type permitting leveling of the platen and accurate adjustment of printing pressure. The stamper arm S also includes platen driving mechanism including a rock shaft 21 drivingly connected to an input arm 23 and an output arm 25. The shaft is oscillated through an angle of about 75 by a drive link 27 connected to input arm 23, which link is reciprocated in a well known manner by the machine mechanism so that the tip of arm 25 oscillates along a line perpendicular to the lines of characters on printing device D.

The description thus far relates essentially to previous equipment of known design upon which the machine of the present invention is based.

The present machine differs from the previously known equipment primarily in the makeup of the platen mechanism P which includes a platen mechanism frame casting 101 to which are attached a pair of

rails

103, 105 by screws 107 (FIG. 4). The rails run parallel to the front of the machine and also parallel to lines of characters on the printing devices D. A platen carriage 109 is made up of end plates 111 and 113 joined by tie rods 115 and an upper central rock shaft 117. The opposite ends of the rods 115 outside the plates 111 and 113 carry rollers 119 for engagement with the lower surfaces of

tracks

103 and 105, and the plates 111 and 113 each have a central ear 111' and 113 respectively upwardly extending between the tracks and carrying a roller 120 engaging the upper surface of the adjacent track.

The lower portions of end plates 111 and 113 are formed with downwardly opening slots 121 each of which slidably and rockably embraces a bushing. These bushings are best seen, perhaps in FIGS. 4 and 5, wherein the bushing embraced by the slot 121 in plate 111 is designated 122, while that embraced by the slot 121 in plate 113 is designated 123. The bushings each have an annular groove, designated 122a and 123a respectively, for receiving and being guided by the plate margins adjacent the corresponding slot. Bushing 122 includes an integral spring anchor arm 12217 and an integral toggle link 122C. Similar elements 123!) and 123c are integrally associated with the bushing 123.

These bushings are designed to support a platen shaft assembly 125, for rocking movement about its axis, and to move the same bodily in a vertical direction laterally of its axis. The

bushings

122 and 123 together with the platen shaft assembly 125 constitutes a platen support means.

The platen shaft assembly comprises a central shaft made up of two sections 125a and 1251; which lock together by virtue of matching flats indicated at 127, and are held as a unit by a central threaded pin 129 which has a hand knob 131 and which passes through a central opening in shaft section 1250: to thread into section 12517 and clamp section 125a thereagainst. For convenience in disassembly, pin 129 is trapped within shaft section 125a by a cross pin 132 located adjacent a reduced section 133 of the pin 129. Shaft section 125a includes an integral knob 135. Shaft section 12517 is supported within bushing 122 and at its free end is drivingly connected to a detent drum 137 and a shift pinion 139, the purpose of which will be subsequently explained. The distal end of shaft section 12512 is occupied by a rotatable cam follower roller 141. The shaft section 125b is preferably trapped within the bushing 122 by a cross pin 134 to simplify assembly of the parts.

On the platen shaft assembly between the

bushings

122 and 123 is rotatably supported a platen roller 143 flanked by platen gears 145 and 147. The platen roller is keyed to at least one of said gears (gear 145 in the form shown) by a tongue 149 fitting into a corresponding recess in the gear.

Cushioning stops 151 are attached to plates 111 and 113 for determining the uppermost positions of the

bushings

122 and 123, and tension springs 153 and 155 are provided for urging the bushings towards upward position against the stops 151. Spring 153 is connected between a pin 153a on spring anchor arm 12217 and a spring perch 153]) on plate 111. Spring 155 is similarly connected bet-ween a pin 155a on spring anchor arm 123b and spring perch 15512 on pltae 113. It can thus be seen that the platen shaft assembly 125 normally hangs in

bushings

122 and 123 which are normally held in raised position by

springs

153 and 155.

Also exerting control over the positions of the

bushings

122 and 123 are a pair of toggles (FIGS. 4 and 9 to 12). The first toggle coacts with bushing 122 and includes link 122c heretofore mentioned, and an actuating arm 122d pivotally connected thereto. The opposite end of arm 1220! is rigidly connected to rock shaft 117. The second toggle coacts with bushing 123 and includes link 1230 and an arm 123d also rigidly attached to rock shaft 117. The pivot point of the toggles 1230, 123d, includes a detent roller 157 designed for engagement with a detent catch 159 pivotally mounted on plate 111 and urged downwardly against a stop 161 by a spring 163 (see FIG. 10). From the foregoing it can be seen that the toggles are constrained for conjoint movement by reason of the rigid connection of

arms

122d and 123d with the shaft 117.

The platen carriage 109 is designed for reciprocation along the

tracks

103, 105, and when the platen 143 is in lowered position it will provide rolling pressure for making an impression upon a document superimposed upon the printing device D. In order to insure proper rolling contact with the document, the platen is positively driven durings is traverse. This is accomplished by the following mechanism, which includes a pair of racks 165 extending parallel 'with the direction of platen carriage motion and supported at their ends in brackets 167 and 169 mounted on the frame casting 101.

Each rack supports a small gear carriage which includes a plate 171,

flanged rollers

173, 173 and a gear 175 underlying and meshing with the rack (FIGS. 7 and 8). A gear support linkage system connects the axis of each gear 175 with the axis of one of the platen gears 145 and 1-47. Taking gear 145 as an example, a link 177 is pivoted at one end of the axis of its gear 175, and at the other pivotal ly joins a second link 179 which has its free end encircling the hub of gear 145. Link 179 carries a first idler pinion 181 at the axis of its pivotal connection with link 179, which idler pinion has a diameter selected so as to mesh with gear 175. A second idler pinion 18'3 mounted on the link 1=79 meshes with both idler 1'81 and gear 145. The link 179 is loosely connected with the adjacent toggle link 1220 by the pin and slot connection 185 and the pin and enlarged hole connection 187, so that the two move generally together as the toggle folds and straightens, but some slight relative motion is permitted for a purpose which will subsequently appear. The platen gear 147 has a similar drive system and the parts are identified by the same reference characters. Since the gear 145 is the only one presently keyed to the platen 143, of course its gear drive system is the only one acting on the platen in the present instance.

From the foregoing it can be seen that travelling of the platen carriage along the tracks 1'03, 105 causes the gear carriages to slide along the racks 165 with a consequent positive driving of the platen gears 145 and 147 through their respective trains of idler pinions 181, 1 83, and the corresponding rack engaging gear 175. The

ratio of the pitch diameter of each gear 175 and its

corresponding platen gear

145 or 147 is selected to give a peripheral platen speed equal to the speed of platen travel and thereby provide a smooth rolling action, and the platen is thus positively driven regardless of whether it is raised or lowered or in any intermediate position.

Means are provided for raising and lowering the platen at appropriate points in the reciprocatory movement of the platen carriage. Turning to FIG. 2, as the carriage 109 moves towards the left, the platen will remain in its uppermost position for about one-half of the stroke. At that point the cam follower roller 141 on the end of the platen shaft will come into contact with a sloping cam surface 189 of a cam plate 191 secured to a sideplate 193 mounted on and depending from the casting 101. The cam plate mounting is preferably adjustable, as by slot 195, to permit accurate setting of the Zone within which the platen is lowered. The cam surface 189 acts on the follower roller until the

toggles

122d, 122a and 123d, 1230 are nearly straight. Thereupon the action is completed by a toggle actuating lever 197 drivingly connected to shaft 117, which lever strikes an abutment 199 adjustably mounted in the casting 101. This action straightens the toggles to the FIG. 8 position where they are held by the engagement of catch 159 with detent roller 157 as seen in FIG. 12. The platen 143 is then in lowered position ready for printing. On the return stroke of the carriage 109, the platen 143 remains lowered and rolls across the printing area making the desired impression on a document placed above the printing device D. As the carriage nears home position, the toggle actuating lever strikes another adjustable abutment 201 (FIG. 7) which breaks the toggle, releasing it from catch 159 and allowing the platen to be raised by

springs

153 and 155, ready to start another cycle.

The drive linkage for reciprocating the platen carriage 109 is best seen in FIGS. 1 and 3 and comprises a bracket 211 extended laterally from the sta-mper a'rm S and provided at its outer end with a pivot post 213. Pivoted on the post 213 for swinging movement in a horizontal plane is a first drive lever 21-5 having an arm 217 con nected to the output arm 25 of rock shaft 21 by a link 219 having suitable spherical bearing connections. The out put arm 25 may be considered the primary drive element for platen operation. Drive lever 215 has a normally driving connection with a secondary drive lever 221 also pivoted on post 213 and having its free end joined to the tie bar of platen carriage 109 by a link 223'. As stated above the first lever 215 and secondary lever 221 norm'ally move as a unit as if they were an integral bell crank. There is provided between them, however, a throwout or overload connection 224 which includes a recess 225 in the hub of secondary lever 221, and a detent roller 227 normally drivingly occupying said recess. The roller 227 is carried on an arm 229 pivoted on the lever 215 and urged towards the hub of lever 221 by a spring 231. So long as the roller remains in recess 225 the arm 217 of lever 215, and lever 221 will maintain their relative angular relationship and the carriage 109 will travel through its normal stroke in response to oscillation of the output arm 25. In case any significant obstruction is presented to the motion of the platen carriage 109, e.g. an obstacle such as the operators hand beneath the platen as it seeks to move downwardly, the extra load offered will cause the roller 227 to lift out of the recess 225 against the force of spring 231 and roll idly around the hub of lever 221 which will then remain in its stalled position as seen in FIG. 3a. In order to insure that the drive does not reengage on a subsequent cycle before the obstruction is cleared, a safety latch in the form of a circular plate 233 matching the hub of lever 221 and having a recess 235 corresponding to recess 225 is provided between the levers on pivot post 21 3. A spring 237 urges the latch in a direction to misalign the

recesses

225 and 235. Therefore, as soon as the roller is displaced from recess 225, the latch swings to close it and to present a continuous hub periphery to the roller 227. Thereafter no driving action is imparted to the lever 221 until the latch 233 is restored to a position with the

recesses

225 and 235 aligned and the roller 227 is again allowed to drivingly engage in recess 225. In order to simplify resetting of the latch, the plate 233 is provided with an arm 239 by which it can be manually swung to recessaligning' position against the force of spring 237.

One feature of the present invention rel-ates to effecting an accurate cut-off point to the printing pressure. As can be seen in FIG. 2, it is customary to trim away sections of the platen as indicated at 143a to produce an edge 14311 and make the printing surface of the platen correspond approximately in length to the area to be printed. One end of this area (at the left in FIG. 2) will usually be relatively indeterminate because the lines of characters may vary in length. However, these end characters are usually rather remote from the limits of the printing area and do not offer a problem. At the other end, however (to the right in FIG. 2), the margin is usually straight and the end characters often approach rather closely to the edges of the ribbon guide or other printing area limiting member on the machine. In order to secure a neat impression it is desirable to have the edge of the cut-away platen give full coverage on the type characters and still avoid reaching as far as the limiting member, since rolling over the latter is likely to give a false impression or smudge which is manifestly undesirable. It is known, of course, to control platen area coverage by accurately trimming the platen to place its edge 14% exactly where required. Since this must usually be effected by removing the platen from the machine, it is a troublesome and sometimes annoying operation. Moreover it provides a fixed result which does not admit of making adjustments for slight differences in the print-ing situation that may arise, unless additional platens are constructed for each such situation. In accordance with the present invention it is necessary to have a single platen for most conditions within a substantial range. This platen may be trimmed to provide cut-off edge 14317 which is only approximately where required. An accurate final setting is achieved on the machine by adjusting the lengthwise position of the rack 165 drivingly associated with the platen (i.e. the right-hand rack in FIG. 4). To this end the racks 165 have slidable mounting in the brackets 167 and 169 and their endwise positions may be set by adjusting screws 164 Whose heads are arranged to fit into matching recesses 166 in the upper surface of the rack (BIG. 2). It will be realized that endwise shifting of the rack 16-5 will, through

gear trains

175, 1811, 183, 145 bring about a small angular motion of the platen relative to that position determined by the home position of the platen carriage 109. Accordingly the line Where platen edge .1431) terminates the printing action will be shifted a corresponding amount. When the correct platen position is achieved, the adjustment can be secured by tightening a clamping bar 241 against the racks 165 by means of screws 243.

In the operation of the machine the cycling of the platen is controlled by the oscillation of output arm 25 which moves in time with the feeding forward of printing devices D in a manner well known. As the arm 25 moves forward from its home position as seen in FIG. 1, it will rock the bell crank, made up of

levers

215 and 221, in a clockwise direction (FIG. 3) thereby drawing the platen carriage 109 to the left in FIGS. 2 and 3 along

rails

103, 105. It will be understood that during this leftward movement a previously used printing device D is being discharged from printing position and being replaced by another from which an impression is about to be taken. Approximately midway of the leftward travel of the carriage 109, cam follower roller 141 encounters the cam surface 189 which gradually lowers the platen shaft assembly 125 in opposition to the force of

springs

153 and 155. As the carriage 109 approaches its leftward limit of movement, the toggle actuating lever 197 strikes abutment 199 to complete straightening of the

toggles

122e, 122d, and 123a, 1230'. The platen is thereupon held in down position by the engagement of detent roller 157 with the catch 159. This brings the output arm 25 to the end of its forward travel so that it reverses and starts to move rearwardly, swinging the bell crank 215, 221 in a counterclockwise direction (FIG. 3), resulting in movement of the platen carriage 109 towards the right with the platen 143 in lowered position. During this movement to the right the now-lowered platen takes an impression from the printing device D therebeneath. As the carriage 109 approaches the limit of its travel towards the right, the toggle actuating lever 197 strikes abutment 201 to break the toggle and permit raising of the platen shaft assembly 125 by

springs

153 and 155, restoring the parts to home position ready for another cycle. It will be understood from the previous description that if at any time during the motion of the platen carriage 109 a load substantially higher than that normally occasioned by a printing action is introduced, the throwout mechanism 224 will become effective and the

levers

215 and 221 will lose their interconnection and become free to change their angular relationship as indicated in FIG. 3a. Safety latch 233 will then prevent a reconnection of the levers so that the output arm 25, link 219 and lever 215 will continue to idle without driving lever 221 until the obstruction introducing the load has been cleared and the arm 239 has been operated to disable the safety latch and restore the driving connection between

levers

215 and 221.

The form of the invention described above represents a simpler construction using a single platen roller. The equipment, however, is capable of handling more than one platen roller for certain applications, and this is the form which is presently preferred. The mechanism employed is in all respects the same, except that a modified platen shaft assembly 325 is used in place of the shaft ca assembly 125, and the main features of this shaft are illustrated in FIG. 6. The assembly is made up of a first shaft section 325a and a second shaft section b, the latter identical with that in the FIG. 5 form. The two shaft sections are also connected by a threaded pin 129 with knob 131 as in the FIG. 5 form. The essential difference between the constructions is in the configuration of the first shaft section 325a which, instead of having central concentric bearing portions, is provided with two bearing

portions

326 and 328, whose axes are each offset from the axis of the shaft 325 with an eccentricity of about .025 inch, and preferably in opposite directions. The bearing portion nearest the second shaft section 125b, i.e'. portion 328, is also of smaller diameter than the bearing portion 326 to permit assembly and disassembly of the parts. Mounted for rotation in bear ing portion 326 is a short platen roller 343 and beside it the platen gear 147 to which it is keyed by a platen projection 348 received in a corresponding recess in the gear. Mounted for rotation on bearing portion 328 is a longer platen roller 343 and the platen gear to which it is keyed by a projection 349 received in a corresponding recess in the gear.

It can be seen from the foregoing that an arrangement is provided by which either of the two platen rollers can be brought into operative position for printing while the other is shifted to inoperative position. In FIG. 6 the short platen 343 is in operative position and platen 343' is inoperative. If the shaft section 325a were rotated the eccentricity of the bearing

portions

326 and 328 would retract platen 343 and move the platen 343' to operative position. This shifting motion can be manually effected by knob 135 which forms a part of shaft section 325a. In order to determine the proper platen locating positions for the shaft assembly 325, it will be noted that the detent drum 137, which is drivingly connected to the shaft section 12511 as in the FIG. 5 form, has two oppositely directed recesses 358 (see also FIG. 9). These are intended for engagement with a detent roller 360 carried by lever 362 pivoted on spring anchor arm 1221: and urged by a spring 364 in a direction such that the roller 360 is forced into the detent drum recesses 358. The shaft assembly 325 may, therefore, be snapped into either of two positions so that one platen roller or the other is operative, and be held in the selected position by the roller 360 until a subsequent shift is effected.

The preceding paragraph describes how the desired platen roller 343 or 343' may be selected by manual shifting. Means is also provided, however, for effecting such shifting automatically in certain cases. With particular reference to FIGS. 4, 13 and 14, the sideplate 193 of the platen assembly P has pivoted thereon a short rack element 366 swingable between a lower operative position and an upper inoperative position determined by a stop pin 368 extending through opening 370 in the rack. In the lower position the teeth of rack 366 lie in the path of the shift pinion 139 as the platen carriage 109 moves towards the left with the platen shaft raised, but are, of course, out of the path of the pinion 139 when platen carriage moves towards the right with the platen lowered. The length of the rack 366 is such as to produce about one-half turn of pinion 139 and hence of shaft assembly 325. A pivoted intermediate lever 372 is connected at one end with the rack 366 and at the other with a manual control lever 374 provided with a handle 376. Both levers are pivoted on sideplate 193. Acting between the pivot of lever 372 and a pin 378 on an extension of lever 374 is an over-center spring 380 which causes handle 376, and hence rack 366, to snap to either up or down position and to hold both in such position until forcibly changed. Thus when the handle 376 is down, as seen in FIG. 13, each leftward traverse of the platen carriage 109 will result in 180 rotation of pinion 139 and shaft assembly 325, and the platens will automatically alternate in occupying opera- 9 tive position. When the handle 376 is raised, the rack 366 becomes inoperative, and whichever platen is selected will remain in operative position until a change is desired.

In general the operation of the preferred form of the device is like that of the simpler form described above, and a detailed description thereof is accordingly unnecessary. It will suffice to point out that the pin and slot connection 185, and the pin and enlarged hole connection 187 come into play when the preferred platen shaft assembly 325 is in use. Since the gear support links 179 are each rockable on the hub of the

corresponding platen gear

145 or 147, they are of course slightly eccentric to the main shaft axis. The toggle links 1220 and 1230 and their attached bushings, on the other hand, are rockable on concentric surface portions of the

shaft

325a, 125b. It is apparent therefore, that during the platen shift operation when the shaft assembly 325 is being rotated, some relative movement of these links must occur, and these

connections

185 and 187 are arranged to accommodate this movement. The slot direction used in connections 185 is such that relative pivoting movement about the platen shaft of toggle link 1220 or 1230 and the gear support link 179 corresponding thereto is prevented. Accordingly, each platen can be maintained in an accurately determined angular position which is determined solely by the position of carriage 109 acting In cooperation with the rack 165.

In addition, the preferred form of platen shaft assembly 325 provides for positively driving both platens, each of which is keyed to its platen gear (see projections 348 and 349). Accordingly each platen is rotated by its respective gear train from its rack 165 whenever the platen carriage 109 is moved. Moreover, the printing cut-off point of each platen is individually settable by means of the adjustment screw 164 associated with its corresponding. rack 165 in the manner described for platen 143 above.

A printing device D of a type which the equipment of the present invention is especially adapted to handle is shown in FIG. 15. In the example shown the device D is a plate of sheet material embossed with printing characters. There are shown three lines of

characters

381, 382 and 383 which are conventional in nature and a fourth line 384 in which the characters are special machine code characters, i.e., they are so configured as to provide for printing a known kind of magnetic code impression, commonly referred to as E-13B type. The printing device is therefore said to contain a plurality of closely spaced rows of impression characters in side-by-side relation, one row of which contains a series of machine recognition characters requiring a high order of impression uniformity to provide operative response. The equipment of the preferred form (FIG. 6) will normally be so designed that the longer platen 343' (FIG. 6) will operate in an area corresponding to type

lines

381, 382 and 383, while the shorter platen 343 will operate in an area corresponding to type line 384, both platens, of course, rolling lengthwise of the type lines.

With the printing machines heretofore known, adjustments are provided such that each printing device D may be automatically held in printing position for two platen passes before discharge. When the machine is so adjusted, and with the handle 80 in lowered position, it can be seen that a first impression will be taken from

lines

381, 382 and 383 on the first pass by platen 343', and a second impression will be taken from line 384 on the second pass by platen 343. Of course these can be reversed depending upon the angular setting of the shaft assembly 325 at the first pass. In this manner the impression taken from line 384, which is the impression having the most critical limitations, is wholly individual. The impression is made one small increment at a time which inherently corrects for variations in type levels along the line arising from minute embossing variations. More important, perhaps, each character in line 384 is imprinted by itself so that varying extraneous pressure influences which would be introduced by the presence or absence of characters in other lines being imprinted at the same time, are altogether avoided. Under these conditions, and using appropriate high fidelity carbon paper as the transfer medium for making the impression, it is possible to achieve a quality not heretofore regarded as practical when using embossed printing devices, and a quality which meets American Bankers Association specifications, whereby the impressions obtained are readable by automatic sensing equipment on a practical basis.

One important economic factor in the operation of printing machines of the type herein described is the iconsumpti-on of transfer material. Inked cloth ribbons usually prove to be the most economical material for this purpose, but do not provide adequate impression quality for Work involving machine sensing of code impressions. Carbon paper ribbon best answers the needs of such application but is quite costly by comparison, especially when ribbon of a complete transfer type is used. This means that the ribbon needs to be advanced the length of the printing area each time an impression is made to present an unused area for the next impression. A characteristic of the previously known printing machines of the type under discussion is that ribbon advance is mechanically associated with platen operation so that a fixed increment of ribbon is fed for each stroke of the platen mechanism. When we maintain the printing device D at printing position for two partial impressions, as described above, this would normally require use of a length of ribbon equal to twice the length of the printing area to take a complete impression from the device D. To avoid the extremely high transfer material costwhich would result, a method has been devised whereby substantially no more ribbon is used than would be the case if the whole impression were made at one pass of the platen carriage 109. This is accomplished by merely progressing the ribbon by a step equal in amount to about onehalf the printing area length at each platen carriage cycle. In this way the impressions are staggered as indicated diagrammatically in FIG. 16 which illustrates a ribbon of transfer material 385 upon which the locations of the impressions of the various lines of type 381-384 are indicated by corresponding line segments, designated 381'- 384'. From this it can be seen that the partial impressions will actually not interfere with one another, and that by this method impressions can be made using two passes of the platen carriage for each impression without consuming any more of the carbon ribbon than if the whole impression were made in one pass.

While the forms of the invention shown and described herein are admirably adapted to fulfill the objects primarily stated, it is to be understood that it is not intended to confine the invention to the forms disclosed herein, for the invention is susceptible of embodiment in other forms and variations. It will be understood, therefore, that the invention is claimed in any of its forms or modifications falling within the spirt and scope of the language employed in the appended claims.

What is claimed is:

1 A printing machine of the character described compns ng means for holding a printing device in printing position in a plane; a platen carrage reciprocable adjacent said printing position in a path substantially parallel to the plane of the printing device; a platen supporting means on the carriage; two roller platens rotationally supported by said platen supporting means and arranged to sweep past adjacent non-overlapping portions of the printing device, with their axes extending transversely of the direction of carriage motion and each movable between an extended position relative to said platen sup porting means in which its axis is shifted towards the plane of the printing device and a retracted position relative to said platen supporting means in which its axis is more remote from the plane of the printing device than 1 1 said extended position; and means for shifting either platen selectively to one or the other of said extended and retracted positions and shifting the other of said platens to the opposite position.

2. A printing machine as set forth in claim 1 which also includes means for shifting said platen supporting means bodily between an extended printing position relative to said carriage in which the extended one of said platens cooperates with said printing device, and a retracted position relative to said carriage preventing cooperation of either platen with said printing device.

3. A printing machine as set forth in claim 1 in which said shifting means includes a shaft; means for mounting said shaft for rotation about its axis; and separate bearing portion-s on said shaft, one for each of said platents, with their axes offset from the shaft axis in different directions.

4. A printing machine as set forth in claim 1 which also includes means for operating said shifting means to shift said platens alternately into extended position in response to the reciprocatory movements of said platen carriage.

5. A printing machine as set forth in claim 3 which also includes means for rocking said shaft to shift said platens alternately into extended position in response to the reciprocatory movements of said platen carriage.

6. A printing machine as set forth in claim 5 in which the means for rocking the shaft includes a gear on the platen shaft and a rack segment positioned for engagement by the gear during platen carriage travel.

7. A printing machine as set forth in claim 6, which further includes means for moving the rack out of the path of the gear to disable the gear and segment shifting operation at will.

8. A printing machine of the character described comprising means to hold a printing device at a printing position in a plane with the lines of characters thereon oriented in a predetermined direction; power drive means comprising a primary drive element oscillatable in a path generally transverse to said predetermined direction; a platen carriage shiftable parallel to said predetermined direction; means including a bell crank for connecting said primary drive element and said carriage, and imparting movement from the former to the latter; a platen shaft rotatable on the carriage extending transversely of the direction of carriage motion and having a pair of bearing portions with their axes offset from the shaft axis in different directions; two roller platen-s supported on said shaft, one on each of said bearing portions; means for shifting said shaft bodily between an extending position adjacent the plane of the printing device and a retracted position remote thererom; two racks one corresponding to each of said platens extending along the direction of carriage motion; and individual means for rotating each platen in response to carriage motion, each of said means including a gear engaged with the corresponding rack.

9. In a printing machine, a frame; a platen carriage shiftable along the frame; a toggle mechanism supported at one end on the carraige; a platen shaft supported by the other end of the toggle mechanism and subject to raising and lowering movements in response to folding and straightening of the toggle mechanism respectively; a roller platen carried on said shaft; cam means associated with the frame and coacting with means carried by the toggle mechanism for partially straightening the toggle mechanism in response to motion of said carriage in one direction; abutment means on the frame and toggle mechanism for completing straightening of the toggle mechanism as the carriage motion in said one direction is completed; detent means on the carriage and toggle mechanism for maintaining said toggle mechanism in straightened condition during carriage travel in the other direction; and abutment means on said frame and toggle mechanism operative at completion of carriage travel in said other direction for overcoming said detent and breaking said toggle mechanism to permit folding thereof and raising of said platen.

10. A printing machine of the character described comprising means to hold a printing device having lines of printing characters thereon at a printing point with the lines of characters oriented in a predetermined direction; power drive means including a primary drive element oscillatable in a path generally transverse to said predetermined direction and substantially parallel to the printing surface of the printing device; a roller platen; a platen carriage supporting said platen and shiftable parallel to said predetermined direction, and means including two levers for connecting said primary drive element and said carriage and imparting movement from the frorner to the latter, said levers being relatively swingable about a common pivotal axis; means for normally interconnecting the levers for conjoint movement while permitting a change in their angular relationship under overload conditions comprising detent means on one lever normally urged into a recess on a hub of the other lever; blocking means movably associated with said other lever; and means urging said blocking means towards a position blocking access to said recess to prevent reengagement of the detent in the recess whenever it leaves the same until the blocking means is reset.

11. A printing machine of the character described comprising means for holding a printing device in printing position in a plane; a reciprocable platen carriage; a platen supporting means on the carriage; two roller platens rotationally supported by said platen supporting means in end-to-end relation with their axes transverse to the direction of carriage reciprocation; two racks, one correponding to each of said platens extending along the direction of carriage motion and relative to which the carriage is movable; individual means for rotating each platen in response to carriage travel, each said means including a gear drivingly associated with the related platen and meshing with the corresponding rack; and means for bodily shifting each of said platens relative to the platen supporting means into an extended position closer to the plane of the printing member and for simultaneously bodily moving the other platen relative to the supporting means to a retracted position more remote from the plane of the printing member.

12. In making an operative printed reproduction from an embossed printing device, wherein the device contains a plurality of closely spaced rows of impression characters in side-by-side relation, one row of which contains a series of machine recognization characters requiring a high order of impression uniformity to provide operative response, the method comprising the steps of:

providing support means for holding an embossed printing device and a form to be imprinted in superposed relationship;

providing a platen holder and a guide means for establishing a path of relative movement of said support means and platen holder in afixed spaced relationship;

providing a first platen roller carried by said platen holder dimensioned and aligned to roll along only said one row of characters, and a second platen roller dimensioned and aligned to roll along other than said one row of characters;

on one occasion, placing said first platen roller a fixed distance from said platen holder such that it will roll along said one row in printing contact and said second platen roller to a non-contact position, and with the platens thus positioned, driving said support means and platen holder relative to one another along said path; said,

on another occasion, placing said second platen such that it will roll along other than said one row of characters in printing contact and said first platen 13 roller in a noncontact position, and, with the platens 2,065,690 12/1936 thus positioned, driving said support means and 2,092,026 9/1937 platen holder relative to one another along said path. 2,104,863 1/ 1938 2,359,849 10/1944 References Cited 5 2,935,939 5/ 1960 UNITED STATES PATENTS 341323 1,280,192 10/1918 Duncan 10156 1,921,511 8/1933 Elliott 101-90 X 14 Gould et a1 10190 X Schaefer 101-56 Hueber 101-274 Hueber 10156 Doherty et a1. 101-269 Maul 101-269 Johnson 10156 WILLIAM B. PENN, Primary Examiner.

Claims

1. A PRINTING MACHINE OF THE CHARACTER DESCRIBED COMPRISING MEANS FOR HOLDING A PRINTING DEVICE IN PRINTING POSITION IN A PLANE; A PLATEN CARRIAGE RECIPROCABLE ADJACENT SAID PRINTING POSITION IN A PATH SUBSTANTIALLY PARALLEL TO THE PLANE OF THE PRINTING DEVICE; A PLATEN SUPPORTING MEANS ON THE CARRIAGE; TWO ROLLER PLATENS ROTATIONALLY SUPPORTED BY SAID PLATEN SUPPORTING MEANS AND ARRANGED TO SWEEP PAST ADJACENT NON-OVERLAPPING PORTIONS OF THE PRINTING DEVICE, WITH THEIR AXES EXTENDING TRANSVERSELY OF THE DIRECTION OF CARRIAGE MOTION AND EACH MOVABLE BETWEEN AN EXTENDED POSITION RELATIVE TO SAID PLATEN SUPPORTING MEANS IN WHICH ITS AXIS IS SHIFTED TOWARDS THE PLANE OF THE PRINTING DEVICE AND A RETRACTED POSITION RELATIVE TO SAID PLATEN SUPPORTING MEANS IN WHICH ITS AXIS IS MORE REMOTE FROM THE PLANE OF THE PRINTING DEVICE THAN SAID EXTENDED POSITION; AND MEANS FOR SHIFTING EITHER PLATEN SELECTIVELY TO ONE OR THE OTHER OF SAID EXTENDED AND RETRACTED POSITIONS AND SHIFTING THE OTHER OF SAID PLATENS TO THE OPPOSITE POSITION.