US3581658A

US3581658A - Printing roller assembly for duplicating machines

Info

Publication number: US3581658A
Application number: US845185A
Authority: US
Inventors: Robert A Shepherd Sr
Original assignee: Scriptomatic Inc
Current assignee: Scriptomatic Inc
Priority date: 1969-07-28
Filing date: 1969-07-28
Publication date: 1971-06-01
Anticipated expiration: 1988-06-01
Also published as: GB1227107A; DE1958806A1; FR2056120A5; JPS4840010B1

Abstract

A duplicating machine in which a facsimile of indicia is imprinted on a moistened area of a workpiece from a master card as the card and workpiece advance forwardly through a printing zone from a feed station to a discharge station is provided with a roller assembly for applying printing pressure in successive stages in the printing zone. Printing pressure is applied in a first stage adjacent the feed station and between a printing roller and an advancing roller respectively overlying and underlying the path of movement of the card and workpiece, and printing pressure is applied in a second stage adjacent the discharge station by a similarly disposed set of rollers. In the first stage, the printing roller is mounted for pivotal movement on the fixed axis of the printing roller in the second stage and spring biased downwardly toward its associated advancing roller which has a fixed axis, and in the second stage the advancing roller is mounted for pivotal movement in the fixed axis of the advancing roller in the first stage and is spring biased upwardly toward its associated printing roller, which has a fixed axis, to frictionally drive the printing rollers at substantially equal velocities as the card and workpiece advance therebetween. In addition, the printing rollers are coated with a layer of tetrafluoroethylene to obviate their normal tendency to accumulate carbon particles from the master card and transfer them to the workpiece.

Description

United States Patent [72] lnventor Robert A. Shepherd, Sr.

Mount Royal, Montreal, Canada 211 Appl. No. 845,185 [22] Filed July 28, 1969 [45] Patented June 1, 1971 [73] Assignee Seriptomatic,lnc.

Philadelphia, Pa.

[54] PRINTING ROLLER ASSEMBLY FOR DUPLICATING MACHINES 14 Claims, 3 Drawing Figs.

[52] U.S.C1 101/132, 101/53 [51] Int. Cl. ..B4lc 47/46, B41f 11/08, 83% 3/04 [50] Field otSearch 101/52,53, 132,132.5, 141

[56] References Cited UNITED STATES PATENTS 1,700,804 2/1929 Menzies. 101/53 2,054,344 9/1936 Storck 101/52 2,854,920 10/1958 Frankie et a1.. 101/1 32X 3,230,871 1/1966 Kooch et al.... 101/53 3,245,342 4/1966 Wright 101/132.5

Primary Examiner-Aldrich F. Medbery Attorney-Howson and Howson ABSTRACT: A duplicating machine in which a facsimile of indicia is imprinted on a moistened area of a workpiece from a master card as the card and workpiece advance forwardly through a printing zone from a feed station to a discharge station is provided with a roller assembly for applying printing pressure in successive stages in the printing zone. Printing pressure is applied in a first stage adjacent the feed station and between a printing roller and an advancing roller respectively overlying and underlying the path of movement of the card and workpiece, and printing pressure is applied in a second stage adjacent the discharge station by a similarly disposed set of rollers. 1n the first stage, the printing roller is mounted for pivotal movement on the fixed axis of the printing roller in the second stage and spring biased downwardly toward its associated advancing roller which has a fixed axis, and in the second stage the advancing roller is mounted for pivotal movement in the fixed axis of the advancing roller in the first stage and is spring biased upwardly toward its associated printing roller, which has a fixed axis, to frictionally drive the printing rollers at substantially equal velocities as the card and workpiece advance therebetween. In addition, the printing rollers are coated with a layer of tetrafluoroethylene to obviate their normal tendency to accumulate carbon particles from the master card and transfer them to the workpiece.

I Patnted June 1, 1971 2 Sheets-Sheet 1 FIGI.

AT T Y3.

Patented June 1, 1971 2 Sheets-Sheet 2 llllllllllliiTTllllllllllii INVENTOR: ROBERT A. SHEPHERD,SR.

I I I I I I I I l I I I I I I I I l I I I I l i IL ATTYS.

PRINTING ROLLER ASSEMBLY FOR DUPLICATING MACHINES The present invention relates to duplicating apparatus, and more particularly, the present invention relates to a printing roller assembly for use in a duplicating machine wherein a fac simile of indicia on a master card is imprinted on an advancing moistened workpiece as they advance through the roller assembly.

There is presently available duplicating apparatus which is adapted to transfer indicia from a master card to a moistened area on a workpiece as the card and workpiece advance between rollers which are biased toward each other to apply printing pressure therebetween. An example of this type of apparatus is illustrated in US. Pat. No. 3,444,807. Although this type of apparatus has proven satisfactory in operation; nevertheless, a demand for improved printing quality and speed has created a necessity for improved apparatus.

In duplicating machines of the foregoing type the printing quality depends, at least to some extent, on the time during which the indicia on the card is in contact with the moistened area on the workpiece, with long contact times causing improved printing quality. In presently available apparatus, printing speed is achieved by short contact times; consequently, the printing quality is frequently not as good as would be desired.

In addition to the relatively short contact time available in present duplicating machines or hectographs, it has been found that relatively high contact pressures are required to ensure adequate facsimile transfer from the master card to the workpiece. As a result, the printed matter on the master card tends to flatten in use, causing the facsimile on the workpiece to lack sharpness. Furthermore, the operational life of the master cards IS reduced since it is customarily discarded when the facsimile it produces on the workpiece tends to be blurred.

When relatively high printing pressures are employed in hectographs, the hectographs must be designed to withstand the loads on the printing rollers, The size of the roller support structure is therefore increased, causing a proportionate increase in the weight and the fabrication costs of the unit.

Heretofore, printing rollers in duplicating machines have tended to accumulate carbon particles in use. As a result, the particles on the rollers have been transferred to the workpieces to cause smudges thereon. At present, smudging is obviated by frequent cleaning of the rollers; however, this is costly and results in periodic downtime of the machine.

In view of the foregoing, it is a primary object of the present invention to provide improved duplicating apparatus adapted to produce clear facsimiles on workpieces at relatively high rates of speed.

It is another object of the present invention to provide a unique printing roller assembly for a duplicating machine to increase the operational life of master cards used therewith.

As another object, the present invention provides a novel duplicating machine wherein the duration of printing contact time is increased and the magnitude of printing pressure is reduced over conventional machines while operating at relatively high rates of speed.

It is a further object of the present invention to provide a new printing roller assembly for duplicating machines to enable the machines to be of compact and lightweight construction.

As a still further object, the present invention provides an improved hectograph roller having a reduced proclivity to accumulate carbon particles so that smudging of workpieces in the hectograph is obviated.

The present invention also provides as an object a duplicating-machine printing-roller assembly which is wear-resistant and relatively maintenance free.

More specifically, in accordance with the present invention, a facsimile of indicia on a master address card is transferred to a paper workpiece as the indicia is pressed thereagainst when the card and workpiece advance between rollers disposed in a printing zone located intermediate a feed station and a discharge station in a duplicating machine. The card and workpiece are operatively compressed between two sets of rollers to effect two-stage printing, an entrance set of rollers being adjacent the feed station and an exit set being adjacent the discharge station. Each set of rollers includes an advancing roller underlying the path of movement of the card and workpiece and a printing roller overlying the path, the rotation of the advancing rollers being synchronized by a gear train and driven by a conventional motor. The printing roller in the first set is carried on a yoke which is biased downwardly toward its associated advancing roller by means of a compression spring which pivots the yoke on a shaft mounted on the frame of the machine. The yoke-shaft mounts the printing roller in the second set toward which its associated advancing roller is biased by an extension spring connected to a cradle assembly pivoted on the rotational axis of the entrance advancing roller. Thus, printing pressure is applied in successive stages as the card and workpiece advance between the rollers. In addition, the printing rollers of the present invention are aluminum and have a coating of tetrafluoroethylene which tends to prevent the accumulation of carbon particles thereon.

These and other objects, features and advantages of the present invention should become apparent from the following description when taken in conjunction with the accompanying drawings in which:

FIG. 1 is a side elevational view of a duplicating machine embodying the present invention and having a portion of its cover broken away to expose a printing roller assembly which is shown in section along the path of movement of address cards and workpieces therein;

FIG. 2 is a sectional view taken along line 22 of FIG. 1 to illustrate the mounting and drive means for the roller assembly; and

FIG. 3 is a schematic diagram showing the apparatus of the present invention in operation with the address card being pressed against a workpiece between the rollers.

Referring now to the drawings, there is illustrated in FIG. 1 duplicating apparatus 10 according to the present invention. As may be seen therein, the apparatus 10 has a shaped cover defining a unitary machine frame 11 housing at one end a printing roller assembly 12 disposed in a printing zone P intermediate a feed station F and a discharge station D. A supply of

master cards

16,16 is contained in a magazine 17 shown at the upper right-hand corner of the figure, and a hopper 18 is provided for receiving the

cards

16,16 as they advance forwardly from the feed station F and through the printing zone P.

The cards C are advanced forwardly or leftward through the printing zone P in overlying relation with a workpiece W which is advanced from a work feeder in which an area of the workpiece is moistened and which causes the workpiece to enter the printing zone P in timed relation with a card 16 so that indicia on the card is in proper registry with the moistened area. The mechanism which effects advancement of the workpiece and card into the printing zone P is more fully described in US. Pat. No. 3,444,807 to which reference is hereby made for a more detailed description thereof. As shown in FIG. 3, after the card C and workpiece W advance through the printing zone P, they are separated so that the cards C are stacked in the hopper 18 and the workpiece W are stacked in a bin 19 hinged to the frame 11 at its lower lefthand end (see FIG. 1).

As noted heretofore, the application of heavy printing pressures to the cards and workpieces tends to flatten the indicia on the cards and causes them to transfer facsimiles which are not entirely clear. In addition, the heavy printing pressures tend to cause the printing roller assembly in conventional duplicating machines to wear, requiring repair and replacement of parts and causing the machines to be temporarily out of service for periods of time. Furthermore, the operational life of the cards used in prior art duplicating machines is not as long as would be desired when they are subjected to heavy printing pressures.

The present invention obviates the foregoing disadvantages and provides a duplicating machine which is able to consistently produce clear facsimiles at relatively high printing rates. To this end, printing pressure is applied to the cards and workpieces in successive stages as they advance through the printing zone, thereby permitting the printing contact time to be increased and permitting the printing pressures to be reduced accordingly. For this purpose, the roller assembly 12 comprises two or more sets of rollers, one set being disposed adjacent the feed station F and the other sets spaced forwardly therefrom adjacent the discharge station D. In the present instance, two sets of rollers are illustrated in the drawings but it will be understood that more may be provided. As may be seen in FIG. 1, the feed and discharge sets include

printing rollers

25 and 26 respectively which are disposed across the normal path of movement of the cards and which overlie the path of card movement; and, the sets include advancing

rollers

27 and 28 which are associated with the

printing rollers

25 and 26 respectively and which underlie the path of card movement. In the present instance, the printing rollers are of the same diameter and are narrower in width than the advancing rollers but correspond to the width of the indicia-carrying area on the cards C so that pressure is applied evenly thereacross.

According to an object of the present invention, the printing rollers remain clean in use. To this end, the roller 26 has a layer of a fluorinated hydrocarbon 26a on its periphery which, in the present instance, is tetrafluoroethylene. In addition, the roller also has a cylindrical aluminum core 26b, to which the tetrafluoroethylene layer is secured in any conventional manner, for example, by shrinking, spraying, painting or dipping. The

rollers

25 and 28 are similarly constructed, the roller 27 being of all rubber construction which facilitates advancing the workpieces through the printing zone. In this manner, a smooth, low-friction surface is provided on the periphery of the printing rollers and the exit advancing roller so that particles of carbon do not tend to adhere thereto and smudge the workpieces in operation.

In accordance with the primary object of the present invention, the printing pressure between associated rollers is applied in stages, and depending upon the relative stiffness of the cards and workpieces, and the type of ink employed, it is desirable to provide means by which the printing pressure may be adjusted to compensate for these variables. For this purpose, the associated rollers in each set are mounted in the machine frame 11 for relative vertical displacement therebetween. As may be seen in FIG. 1, in the first or entrance set, the advancing roller 27 is fixed and the printing roller 27 is movable with respect thereto, and in the second or exit set, the printing roller 26 is fixed and the advancing roller 28 is movable with respect thereto. This mounting arrangement is provided by a bracket 30 and a cradle 50 spanning across the frame 11 above and below the path of card movement respectively.

In the present instance, the bracket 30 mounting the

printing rollers

25 and 26 comprises a backing member 35 spanning across the width of the machine-frame and two

sidewalls

33 and 34 disposed vertically at opposite ends of the

printing rollers

25 and 26 and fastened to the front of the member 35 by means of

bolts

37,37. Mounted on the back of the backing member 35 in the magazine 17 is a gate 31 which is fastened to the member 35 by bolts 32,32 passing through slots 31a,31a in the gate, the gate being vertically adjusted to compensate for the thickness of the cards in the magazine to ensure that only one card at a time is discharged therefrom. The exit printing roller 26 is mounted on a shaft 42 to which it is secured by locking means, in the present instance a setscrew 43 (see FIG. 2). The shaft 42 is journaled in the

sidewalls

33 and 34 and is secured against lateral displacement by means of a pair of locking members 45,45 which engage the shaft 42 and against opposite sides of the sidewall 33. In this manner, the exit printing roller 26 is mounted for rotation at a fixed location in the printing zone P.

The entrance printing roller 25 is carried by the bracket 30 in a manner permitting it to be displaced downwardly toward its associated advancing roller 27. For this purpose, a yoke 46 (FIG. 2) is provided which has depending side arms 47,47 each having a through bore for journaling a shaft 49 to which the roller 25 is securely fastened by suitable locking means. The yoke 46 is pivoted on the shaft 42 by through

bores

51,51. As may be seen in FIG. 2, the

rollers

25 and 26 are mounted against lateral translation in the yoke 46 by means of locking

members

52,52 engaging the

shafts

42 and 49 and one side arm 47.

According to the present invention, the printing pressure may be varied to suit different printing conditions. To this end, the yoke 46 is biased clockwise (FIG. 1) on the shaft 42 by means of a compression spring 55 engaging between a saddle 56 on the top of the yoke and a shouldered element 57 carried by a bolt 59 threadedly mounted on a forwardly protruding portion 3b of the bracket 30. With this arrangement, the compression of the spring 55 and hence the printing pressure between the

rollers

25 and 27 may be varied by rotating the bolt 59 in the proper direction to urge the roller 25 downwardly toward the roller 27.

In accordance with the present invention, the rotational velocity of the exit advancing roller 28 is synchronized with the rotational velocity of the entrance advancing roller 27 by a novel mounting arrangement which also permits the exit advancing roller 28 to be displaced upwardly toward its associated printing roller 26 for adjusting the printing pressure therebetween without affecting the synchronization of the rollers. For this purpose, the cradle 50 has a pair of vertically disposed end walls 60 and 61 (FIG. 2) each having a central through bore which rotatably receives a shaft 64 which isjournaled in the frame 11 and mounts the entrance advancing roller 27. In the present instance, the exit advancing roller 28 is mounted on a shaft 66 journaled in the respective forward portions of the endwalls, and a spacer bar 65 spans between the respective rear portions of the endwalls. In addition, the cradle is mounted against lateral displacement on the

shafts

64 and 66 by suitable locking means engaging the endwalls and the shafts. With this structure, the exit advancing roller 28 may pivot on the shaft 66 into and out of operative relation with its associated printing roller.

In order to bias the exit advancing roller 28 upwardly toward its printing roller 26, resilient means is provided to engage between the spacer bar 65 and the machine frame 11. As may be seen in FIG. 1, the biasing means is an extension spring 69 hooked at its upper end onto the bar 65 and hooked at its lower end through an eye 70 in a bolt 71. The tension on the spring 69 and hence the printing pressure between the exit set of rollers is adjusted by displacing the bolt 71 in a vertical slot 72 in a horizontal strut 74 and a depending plate 73, the bolt 71 and its cooperating nut 75 engaging opposite sides of the strut 74 and plate 73 to lock the lower end of the spring in a selected adjusted position.

In order to insure proper registry of the card with the workpiece throughout the printing zone, the rotation of the exit advancing roller 28 is synchronized with the rotation of the entrance advancing roller 27. In the present instance, the entrance roller 27 is driven counterclockwise (FIG. 1) by a spur gear secured to the shaft 64 at the right-hand side of the frame 11 (FIG. 2), the spur gear 80 being driven by gears 81 and 82 (shown in broken lines in FIG. 1) connected to a drive motor (not shown). In order to couple the entrance roller 27 with the exit roller 28, transmission means is provided. To this end, a spur gear 85 is mounted on the shaft 64 outboard of the cradle endwall 61 to mesh with an idler gear 86 mounted on a stub shaft 87 projecting outwardly from the endwall 61. The idler gear 86 in turn meshes with a spur gear 88 secured to the end of the shaft 66 mounting the exit advancing roller 28, so that upon counterclockwise rotation of the entrance roller 27 when the drive motor is energized, the exit roller 28 also rotates counterclockwise. The desired peripheral velocities of the entrance and exit advancing rollers is ensured by properly compensating for the difference in the roller diameters by providing gears having suitable pitch diameters relative to the roller diameters. Preferably, the peripheral velocity ofthe exit roller 28 is slightly in excess of that of the entrance roller 27 to avoid wrinkling of the workpiece and card. The pivotal mounting of the entrance printing roll on the shaft of the exit printing roll and the pivotal mounting of the exit advancing roll on the entrance roll shaft assist in maintaining proper registry of the card with the workpiece. Thus, the

rollers

27 and 28 advance the cards C and workpieces W through the printing zone P in proper registry without causing smearing, double impressions, or other undesirable effects.

For the purpose of supporting and guiding the cards and workpieces'as they advance between the rollers, guide means is provided' In the present instance, the guide means comprises a series of

tracks

90, 91 and 92 (FIG. 2) which extend through the printing zone P from the feed station F to the discharge station D (FIG. 1). The

tracks

90 and 91 are disposed on opposite outer sides of the rollers, and the track 92 is spaced leftward of the track 91 for guiding wide workpieces. As may be seen in FIG. 1, the tracks each have a downturned forward lip, for example the lip 91a on the track 91 which engages'over the rear of the card hopper 18, and extends rearwardly along the path of travel of the cards and workpieces-and terminates between the magazine 17 and the work feeder. Thus, the tracks cooperate to guide and support the workpieces and cards while they are being advanced into operative relation between the rollers.

The cards C are automatically separated from the workpieces W by the tracks as they enter the discharge station D of the machine. In the present instance, the cards C are guided upwardly on the

tracks

90, 91 and 92 as they advance downwardly, and in order to provide additional motivating force to the cards C to advance them upwardly on the tracks, drive means is provided. As may be seen in FIGS. 1 and 2, the drive means comprises a pair of rollers 100 and 101 mounted outboard of the bracket sidewalls 33 and 34 on the ends of a shaft 102 joumaled thereon. The shaft 102 is rotated by the entrance printing roller 25 through an elastic belt 105 stretched around a pulley 106 on the shaft 49 mounting the entrance printing roller 25 and around'a pulley 107 mounted on the drive roller shaft 102. Thus, when the entrance printing roller 25 is rotated clockwise (FIG. 1) in response to the counterclockwisearotation of the advancing roller 27, the drive rollers 100 and 101 are rotated clockwise to cause the cards C to advance upwardly on the tracks and out of the printing zone P.

In operation, a supply of cards C,C are stacked in the magazine of the machine and workpieces W,W are also fed into the machine. The drive motor is energized to cause the

gears

80, 81, 82, 85, 86 and 88 to rotate the advancing

rollers

27 and 28. By suitable forwarding means as described in the aforementioned patent, a card C from the bottom of the stack and a workpiece W are advanced forwardly into the printing zone P, the imprint area on the workpiece having been moistened with solvent before it advances into the printing zone. As the card C and workpiece W advance between the entrance set of

rollers

25 and 27, the frictional engagement between the card and the workpiece and the rollers rotates the

printing rollers

25 and 26 in synchronism with the advancing

rollers

27 and 28 and the indieia on the card C is pressed against the imprint area of the workpiece W to transfer a facsimile of the card indicia thereto (See FIG. 3). The card C and workpiece W then advance forwardly between the exit set of

rollers

26 and 28 where printing pressure is again applied thereto to effect an additional transfer from the card indieia to the workpiece. The synchronous drive of the rollers, the arcuate form of the tracks, and the fixed spacing between the printing rollers above the printing station P and the advancing rollers below the station maintains continued registry between the card and the workpiece throughout the printing station P. As may be seen in FIG. 3, the card C is separated from the workpiece W as the workpiece engages the card hopper 18 and is cammed downwardly into its bin and is stacked therein,

the card C being advanced upwardly on the tracks and 91 by the drive rollers and 101. If necessary, suitable adjustment may be made to vary the spring force exerted by the

springs

55 and 69 to increase or decrease the printing pressure as required, or other steps may be taken to improve printing quality as described in the aforementioned patent.

In view of the foregoing, it should now be apparent that a novel roller assembly has been provided for a duplicating machine to enable the machine to transfer distinct facsimiles from address cards to workpieces at relatively high production rates, and in a manner which prolongs the operational life of the address cards and the machine.

While a preferred embodiment of the present invention has been described in detail, various modifications, alterations or changes may be made without departing from the spirit and scope of the present invention.

What I claim is:

1. In a machine for imprinting from an indieia-carrying master card a facsimile of the indieia on a moistened area of a workpiece by pressing the indieia against the area as the workpiece and the card advance forwardly through a printing zone located intermediate a feed station and a discharge station in the frame of the machine, the improvement comprising: means disposed in said printing z'one andfor applying printing pressure in successive stages to the master card indieia and the workpiece as they advance therethrough, including a pair of closely spaced printing rollers disposed in said printing zone across the path of movement of said card and workpiece, a first one of said pair being located adjacent said feed station and the second one of said pair being spaced forwardly therefrom along said path of movement, an advancing roller associated with each of said printing rollers and spaced therefrom a distance to cause said printing rollers to rotate when the card and workpiece are operatively advanced therebetween, and drive means to advance the card and workpiece along said path of movement in said printing zone, the roller relationship constituting a means for applying printing pressure in successive stages as the card and workpiece advance through the printing zone.

2. Apparatus according to claim 1 including means mounting said first printing roller and its associated advancing roller for relative displacement toward and away from each other, comprising: a bracket mounted on said frame and having vertical sidewalls at opposite ends of said printing rollers, a yoke disposed between said bracket sidewalls, means mounting said first printing roller for rotation on said yoke, means pivotally mounting said yoke on said bracket, means to mount the first advancing roller for rotation on said frame in registry with its associated printing roller, and biasing means engaging between said frame and said yoke to urge said yoke and said first printing roller thereon toward its associated advancing roller to operatively engage said card and workpiece therebetween, said drive means being connected to the first advancing roller to cause rotation thereof for advancing card and workpiece between said rollers, whereby a facsimile of the indieia on the card is transferred to the workpiece.

3. Apparatus according to claim 2 wherein said yoke-biasing means includes a compression spring interposed between said bracket and said yoke to urge said first printing roller toward its associated advancing roller, and a shouldered element engaging said spring at one end and threadedly mounted on said bracket to effect adjustment of the compression of the spring upon rotation thereof, whereby the printing pressure between the first printing and advancing rollers may be adjusted.

4. Apparatus according to claim 2 including means mount- .ing said second printing roller for relative displacement toward and away from its associated advancing roller comprising: shaft means mounting said second printing roller for rotation on said bracket, said yoke being pivotally mounted on said shaft means, cradle means mounting the advancing roller associated with said second printing roller for pivotal movement about the axis of rotation of said first advancing roller,

means carried by said cradle means rotatably mounting said second advancing roller thereon, means engaging between said cradle means and said frame to bias said cradle means and urge said second advancing roller toward its associated printing roller to operatively engage therebetween said card and workpiece, and transmission means carried by said cradle means and drivingly coupling said advancing rollers to synchronize rotation thereof, so that printing pressure is applied to the card and workpiece in two stages in said printing zone. I

Apparatus according to claim 4 wherein said cradle means includes: a pair of endwalls spaced apart at opposite ends of said advancing rollers said endwalls extending forwardly and rearwardly of said axis of rotation of said first ad vancing roller, and a bar extending between said endwalls and fastened at each end thereto to space said endwalls away from each other; and said cradle-biasing means includes an extension spring having one end engaging said bar and having its other end engaging said frame so that said second advancing roller is biased toward its associated printing roller to cause a second printing of said facsimile to occur at a preselected pressure before said card and workpiece are discharged from said printing zone.

6. Apparatus according to claim 5 including means to adjust the bias of said second advancing roller comprising: a frame member extending across said frame and having a slot, a fastener engaged in said slot for displacement therein and having an eye receiving said other end of said extension spring, whereby the tension in the extension spring and the pressure between the second printing and advancing rollers may be adjusted by displacing said fastener in said slot.

7. Apparatus according to claim 4 wherein said second printing roller mounting means includes a shaft fixedly mounting said second printing roller thereon, said shaft extending through said sidewalls of said bracket, bore means in said bracket sidewalls joumaling said shaft. and means engaging said shaft and at least one of said sidewalls to prevent longitudinal displacement of said shaft in said bore means, whereby said second printing roller is mounted against translation laterally as it rotates.

8. Apparatus according to claim 7 wherein said yoke has a pair of horizontally spaced depending side arms engaging said second printing roller shaft on opposite ends of said second printing roller, and said first printing roller mounting means includes a shaft extending between said side arms, bore means on said side arms rotatably receiving said first printing roller shaft, and means to lock said first printing roller onto its mounting shaft, whereby said first printing roller is confined between said side arms to prevent translation laterally as it rotates.

9. Apparatus according to claim 4 wherein said transmission means includes a spur gear mounted for coaxial rotation with each of said advancing rollers and an idler gear meshing with said spur gears and rotatably mounted on said cradle means, whereby said second advancing roller is rotated in response to the rotation of said first advancing roller.

10. Apparatus according to claim 2 wherein said first advancing roller mounting means includes a shaft journaled to said frame and means to lock said roller thereonto.

1]. Apparatus according to claim 1 including guide means engaging and guiding said card and workpiece along the path of movement thereof through said printing zone, said guide means including at least two tracks disposed on opposite outer sides of said rollers and extending from said feed zone to said discharge zone, so that said card and workpiece are engaged by said guide means and are guided thereby as they advance between said rollers.

12. Apparatus according to claim 1 including a layer of fluorinated hydrocarbon on the periphery of at least one of said printing rollers.

13. Apparatus according to claim 12 wherein said fluorinated hydrocarbon is tetrafluoroethylene.

14. Apparatus according to claim 12 wherein said layer of tetrafluoroethylene is disposed in the form of a tube elastically engaging the periphery ofits respective printing roller.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 581, 658 Dated June 1, 1971 Inventor(s) Robert A. Shepherd, Sr.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 6, line 24, after "zone" insert -to advance said card and workpiece through said printing zone Column 6, line 55, after "advancing" (second occurrence) insertsaid- Signed and sealed this 7th day of September 1971 (SEAL) Attest:

EDWARD M-FLETCHER, JR. ROBERT GO'I'TSCIIALK Attesting Officer Acting Commissioner of Patents FORM PO-105O (10-69) USCOMM DC 5037s p5g n u s, covnmuem Pnnmnc OFFICE I969 o-aes-aa:

Claims

1. In a machine for imprinting from an indicia-carrying master card a facsimile of the indicia on a moistened area of a workpiece by pressing the indicia against the area as the workpiece and the card advance forwardly through a printing zone located intermediate a feed station and a discharge station in the frame of the machine, the improvement comprising: means disposed in said printing zone and for applying printing pressure in successive stages to the master card indicia and the workpiece as they advance therethrough, including a pair of closely spaced printing rollers disposed in said printing zone across the path of movement of said card and workpiece, a first one of said pair being located adjacent said feed station and the second one of said pair being spaced forwardly therefrom along said path of movement, an advancing roller associated with each of said printing rollers and spaced therefrom a distance to cause said printing rollers to rotate when the card and workpiece are operatively advanced therebetween, and drive means to advance the card and workpiece along said path of movement in said printing zone, the roller relationship constituting a means for applying printing pressure in successive stages as the card and workpiece advance through the printing zone.

2. Apparatus according to claim 1 including means mounting said first printing roller and its associated advancing roller for relative displacement toward and away from each other, comprising: a bracket mounted on said frame and having vertical sidewalls at opposite ends of said printing rollers, a yoke disposed between said bracket sidewalls, means mounting said first printing roller for rotation on said yoke, means pivotally mounting said yoke on said bracket, means to mount the first advancing roller for rotation on said frame in registry with its associated printing roller, and biasing means engaging between said frame and said yoke to urge said yoke and said first printing roller thereon toward its associated advancing roller to operatively engage said card and workpiece therebetween, said drive means being connected to the first advancing roller to cause rotation thereof for advancing card and workpiece between said rollers, whereby a facsimile of the indicia on the card is transferred to the workpiece.

4. Apparatus according to claim 2 including means mounting said second printing roller for relative displacement toward and away from its associated advancing roller comprising: shaft means mounting said second printing roller for rotation on said bracket, said yoke being pivotally mounted on said shaft means, cradle means mounting the advancing roller associated with said second printing roller for pivotal movement about the axis of rotation of said first advancing roller, means carried by said cradle means rotatably mounting said second advancing roller thereon, means engaging between said cradle means and said frame to bias said cradle means and urge said second advancing roller toward its associated printing roller to operatively engage therebetween said card and workpiece, and transmission means carried by said cradle means and drivingly coupling said advancing rollers to synchronize rotation theReof, so that printing pressure is applied to the card and workpiece in two stages in said printing zone.

5. Apparatus according to claim 4 wherein said cradle means includes: a pair of endwalls spaced apart at opposite ends of said advancing rollers, said endwalls extending forwardly and rearwardly of said axis of rotation of said first advancing roller, and a bar extending between said endwalls and fastened at each end thereto to space said endwalls away from each other; and said cradle-biasing means includes an extension spring having one end engaging said bar and having its other end engaging said frame so that said second advancing roller is biased toward its associated printing roller to cause a second printing of said facsimile to occur at a preselected pressure before said card and workpiece are discharged from said printing zone.

7. Apparatus according to claim 4 wherein said second printing roller mounting means includes a shaft fixedly mounting said second printing roller thereon, said shaft extending through said sidewalls of said bracket, bore means in said bracket sidewalls journaling said shaft, and means engaging said shaft and at least one of said sidewalls to prevent longitudinal displacement of said shaft in said bore means, whereby said second printing roller is mounted against translation laterally as it rotates.

11. Apparatus according to claim 1 including guide means engaging and guiding said card and workpiece along the path of movement thereof through said printing zone, said guide means including at least two tracks disposed on opposite outer sides of said rollers and extending from said feed zone to said discharge zone, so that said card and workpiece are engaged by said guide means and are guided thereby as they advance between said rollers.

14. Apparatus according to claim 12 wherein said layer of tetrafluoroethylene is disposed in the form of a tube elastically engaging the periphery of its respective printing roller.