US2257490A - Lithographic machine - Google Patents

Description

Sept. 30, 1941. R. ABERLE LITHOGRAPHIC MACHINE v Filed Fey s. 8, 1938 5 Sheets-Sheet 1 MvENToR E a m D 0 Sept. 30, 1941. R. ABERLE LITHOGRAPHIC MACHINE Filed Feb. 8, 1958 ssheets-sheenz INVENTOR Sept. 30, 1941. R. ABERLE 2,257,490

7 LITHOGRAPHIC MACHINE 7 Filed Fab.- 8, 1938 5 Sheets-Sheet 3 INVENTOR BY Roy Aber/e Sept. 30, 1941. R. ABERLE 2,257,490

I'IITHOGRAPHI'C MACHINE Filed Feb. 8, 1958 5Sheets-Sheet 4 N no N rm h INVENTO'R BY (a 1 A O EY Sept; 30, 1941. R. ABERLE LITHQGRAPHIC MACHIZNE Filed Feb. 8, 1938 5 Sheets-Sheet 5 INVENTOR Roy be /e v ATTORNEY offset cylinder thereof as A still further advantage of the reduction in the number and complexity of the parts whereby correspondingjeconomies are Patented Sept. 30; 1941' mnoommo moms Boy Aberle, Long Branch, N. J. Application February s, 1938, Serial No.'189,445

(Cl. on-142) 4 Claims.

This invention relates generally to printing machines and more particularly to such ma.- chines wherein printing matter is transferred from a lithographic printing plate to an offset rubberhlanket or impression cylinder and therefrom to a blank sheet of paper.

Among the objects of this invention is the provision of structure for the rapid and'positive transfer of individual sheets of paper successively through the lithographic printing process.

An object herein is the provision of structure for obtaining accurate registration of each sheet with relation to the printing impression on the through the printing machine.

Another object of the present invention is the provision of means for positively gripping each of the individual sheets fed through the machine and holding the same within the same'positive grip throughout the printing process and until the sheets are released at a predetermined position to form an accurately aligned stack.

A feature of the present invention lies in structure' which replaces feeding rollers by gripping means which assure positive feed and registration, thereby eliminating inaccurate feeding which. occurs when feeding rollers wear into a frustum of a cone shape.

v A still further object herein is structure capable of individual registration adjustment for each sheet handled by the machine.

Another advantage of the. present. machine is the provision of structure in the discharging and stacking mechanism, whereby the sheets, after having an impression put thereon, are inverted so thatthe printed matter thereon appears face up and a constant check up of the clarity of the printing thereon may be easily made.

Another object of the invention is the provision of an oflfsetlithographic machine which takes up little space by virtue of the compact'an'd cooperative arrangement or the various sub-assemblies therein. 7

the invention is accomplished in the manufacture and use thereof. V Y a These'objects and other ends and advantages will more fully appear in "the progress of this disclosure and as pointed out in the appended claims. v p

r In the accompanying drawings right and left hand designations indicate right and left hand sides as the operator fac'esthe front of the mathe provision or.

said sheet is carried chine, that is, tliat portion of the machine adapted to co-operate with a feeder, while the same numerals are used to indicate corresponding parts throughout the several views thereof.

Figure l is a left side elevational view of a preferred embodiment of the invention in which the feeding mechanism has been removed.

Figure 2 is an enlarged vertical sectional view of the registering and associated mechanisms as seen from the plane 2-2 on Figure 4.

Figure 3 is an enlarged fragmentary elevationalview of a sheet carrying-clip in the open position thereof as the same is about to close upon Figure 4 is a-horizontal fragmentary sectional view taken along the plane tL-J indicated on Figure 1.

Figure 5 is a view taken similarly to Figure 4 with the exception that same shows an alternate embodiment of the sheet registering mechanism. .Figure 6 is an enlarged fragmentary vertical sectional view taken along the plane 6-4 on Figure 5.

Figure '1 is a left side elevational view of certain of the elements shown in Figure 3 showing" thecam for operating the sheet carrying clips.

Figure 8 is a horizontal sectional view showing in plan the alternatesheet registering mechanism which is seen in elevation in the upper right hand corner of Figure 5. V

Figure 9 is afragmentary perspective view showing one end of the sheet carrying clip bar.

The lithographic machine indicated generally by numeral 20 hasthe operating parts thereof. attached or indirectly suspended from a left frame plate 2| and a right frame plate 22. The two frame plates are maintained in aligned parallel spaced position by means of known tie-bars .which are transversely disposed.

A shaft 23 is suitablytrunnioned in the frame plates 2! and 22 and carries fixedly mounted fthereon a drum 2L Drum 24 base circumference substantially twice the length .of a sheet of paper or othermaterial upon which the machine is adaptedto operate. Drum 24 has a sheet backing portion 25 and a lithographic the pivotally mounted hook 2'9. The hook 29 serves. to properly tension the lithographic sheet 21 by reason of the action of a contractile spring 30, the inner end of whichis carried by a pin 3! mounted on a wall of the drum 24.

An offset or blanket drum 321s fixedly mounted upon a shaft 33 which istrunnioned in the frame plates II and 22. The blanket drum 32 has mounted thereon a rubber oifset blanket 34 which 'is secured upon the outer surface of said drum The ratio existing between gears 31 and 38 is two to oneso that the blanket drum 32 makes surfaces against which grippers 59 may'operate.

' The clip bars 49 and 50 are each provided with two revolutions to each revolution of the drum 24, thus picking up a lithographic impression during the first revolution of drum s2 and depositing said impression upon a sheet'of blank material carried by the sheet backing portion on drum 2d. v

The individual sheets of blank material, indicated generally by numeral 39 are picked up and transported through the lithographic process and subsequently discharged by structure now'to be described. Two annular link chains 80 and 4| are mounted for continuous travel within the machine (see Figures 1 and 4) upon four pairs a plurality of grippers 59 which are fixedly attached to a transverse spindle 50 which is journalled in orifices 6| in the clip bar aligning segments52. 0n clip bar 49 the spindle 60 projects to the left of the segment 52 (see Figure 5) out wardly to terminate in attachment to a cam 62. On clip bar 50 the spindle 63 projects to the right of the segment 52 which is on the right hand end of the central portion 5| and terminates in attachment .to a cam 64 (see Figure 1). Iii-order to allow the passage of spindles 60 and tiloutwardly of the sprockets which carry the chains 40 and 4|, each of the sprockets in the pairs. of sprockets 42, 43, 44 and 56 are provided with cut-out portions 55.

Since the clip bars 49 and 50 are affixed to the link chains 40 and 4| as has been described and these chains are carried about in a continuous travel by the four pairs of sprockets as above described, it will be understood that the clip bars 68 and 50 will be more or less free to shift during certain portions of the travel thereof by reason of the looseness in the chains themselves owing to wear in the links. In machines of the present class which are subject to continuous use at relatively high speed, considerable wear ooof sprockets 42, 43, 44 and 55. Sprockets 42 are mounted, one adjacent each of the frameplates upon a transverse shaft 45 which is suitably journalled in the frame plates. Sprockets 43 are mounted, one adjacent each of the frame plates upon a transverse shaft 46 which is: suitably journalled in the frame plates. 44 are mounted, one adjacent each of the frame Sprockets plates upon a transverse hollow shaft 41 which rides about a shaft 48 which is suitably journailed in the frame plates. Sprockets 56 are mounted, one adjacent each of the frame plates and outwardly of drum 32 upon shaft '33. The link chains and 4| have mounted therebetween' two clip bars 49 and 5|l,the end of one of said clip bars being seen in Figure 9 of the accompany drawings. The clip bars 69 and 5d ,are substantially identical in construction with the exception that they are adapted for operation from opposite sides. A description, therefore, let us say, of clip bar 49 will suilice for both. The clip bar 49 has a central portiontransversely disposed of the machine shown in cross section in'Figure 9 indicated by numeral 5i. At each end of portion 5| there'are clip bar aligning segments 52, which have affixed to the upper portion thereof mounting blocks 53. Blocks 53 have threaded orifices in the top walls thereof which are engaged by screws 54. The chains MI and 4| are each provided with'two special links 55 which are equidistant from each other along the in the frame plates 2i and 22.

ours in the links of the link chains 40 and and this wear is not uniform throughout the length of the chains. In order to take up any undesirable slack in the chains 40 and H, the shaft is mounted so that the journalling thereof is adjustable. This adjustment may be made by any suitable means known in the art, as for example the'regulation of the shaft 45 in its position within the horizontally disposed slots While slackin the chains 40 and may be taken up in the manner just described, it is undesirable to have the chains running at too great a tension as this causes excessive wear and since the wear is uneven along the length of each chain, the tightening of the chains will 'not result in better registration of the clip bars 49 and 50 and sheets 38 carried therein with relation to the printing elements of the machine. In order to avoid such undesirable results, registering mechanism in. the form of pairs of disks 61 and '58 is proby the chains 40 and 4| in the indentations 69 and iii-the indentations Hi the clip bars 49 and M are positively andaccurately brought into screws 54 as best seen in Figure 5. Clip bar 4Q has mounted along the portion'5i. a plurality of vertically disposed adjustable pins 51. Plus 51 orloweredi'by inserting a screw driver 'in the slotted shank 58 as seen in Figure 2. The enregister with the clip loading and lithographic printing mechanisms. The disks 5! are fixedly mounted on the hollow shaft 41 while the disks 6d are fixedly mounted on shaft 33.

The clip bars 49 and 50 are adapted to grasp and release individual sheets 39 in their travel along with the chains 40 and M. On each of the clip bars 49 and. 50 the grippers 59 are maintained in a closed or gripping position by'reason of the-action. of coil springs H which encircle the spindles 50 and 5|. This structure is best I seen in Figure 4. The cams 62 and 94 are inthreadedly engage portion 5| and may beraised g spindles and which are squared atthe ter tegrally mounted upon the outer-ands of the minals thereof so that any tendency of the cams to shift thereabout will be eliminated. The cams are adapted to coact withcams 18 mounted upon the gear 18 I l1, and is carriedalong by offset blanket each provided with rollers I2 and 18 which are adapted to act as followers for cams 14 and 18. Cams 14 and 18 are mounted upon shaft 48. Shaft 48 is rotated in a clockwise direction in contrast with the hollow shaft 41 which rotates in a counterclockwise direction as viewed in Figures 2, 3 and "I. Cams 82 and 84 and 11 respectively, cams 18 and 11 being fixedly mounted on the shaft ,48 inwardly of and next to the cams 14 and 18. Since the chains 40 and 4| are moving at relatively high speed, it is necessary that the grippers 88 be opened very quickly and be closed very quickly. Shaft 48 is operated at a speed four times as fast as the shaft 28 and twice as fast as the shaft 82. This speed of operation is secured by means of a gear 18' which meshes with the gear 88 and is mounted upon a suitable 82 and 84 are tie-bar 85 extending between the frame plates stud shaft proiecting'inwardly from the frame plate 2i, the ratio existing 18 being two to one. A gear 18 meshes with gear 18 and also with a gear 80 which is fixedly shaft 48. The purpose of the is merely to reverse the motion so that the shaft 48 will rotate in a direction opposite to the shaft 33. The gear 18 is mounted upon a studshaft projecting inwardly from the frame plate 2|.

Turning to Figures 3 and 7, the action of cam 82 and the roller thereon, and cams 14 and 18 will now be described. In Figure 3, when the machine is in operation the chain 40 is movin as it passes about the sprocket 86 in a counterclockwise direction. The projection 8| of the cam 18 strikes the projection 82 of thecam' 82 when the gripper 88 is in a closed positionas seen in the lower corner of Figure 7. Since the between gears 88 and end thereof upon and 4| are supported against any undesirable means of horizontally disposed gu des the chains 48 and 4|, since only the forward edge thereof is gripped by the clip of spaced skids 82 (see Figure 1) which are curved at the lower ends thereof as indicated by numeral 88. Skids 82 are maintained in position by clamps 84 which secure same to a transverse 2| and 22; As a clip bar carrying a sheet as previously described changes its direction of travel, in passing about the sprockets 42 the sheet 29 is inverted and pulled forwardly in the machine in a horizontal direction. Said clip bar in moving forwardlyof the machine is adapted to have either the roller 12 or the roller 12 strike stationary cam bars 88 or 81 respectively which open the grippers 88 sumciently to release and allow same to fall upon an angularly disposed table 88 having side guides 88 and an end guide I00. Table 88 is suitably supported at the lower end thereof upon a tie-bar Ill and at the upper a tie-bar I02. The chains 48 sagging by I08 and I04 which are suitably attached to the frame plates 2I and 22 by suitable brackets extending inwardly therefrom, as for example the bracket I08 as seen in the lower right hand corner of Figure 4. Thestationary cam bars 88 and Here supported from the guides I08 and I04 respectively by means of brackets I08. A clip bar having been unloaded in the manner just described. that is, by coacting with the staprojection 8| is travelling downwardly as seen' in that view, the cam 82 is rotated in a counterclockwise direction together with the spindle 80 and the gripper 88 is swung back to its open position. The projection 88 on cam 82 engases the indentation 84in the cam 18. The projection 85 on the cam 16- engages the surface 88 on the cam 82 which serves to maintain the cam 82 rotated about in a counterclockwise manner and the grippers 88 in their open position. The projection 88 rides uponthe dwell surface 18 of cam "and the projection 88 then rides upon the fall surface 88 of the cam 18 until the cam 82 rotates so that the roller 12 strikes the-dwell portion 88 of cam 14. Further rotation of the shaft 48 with concurrent opposite movement of the chain 48 will result in a position shown in Figure 3 in which the gripper 08 is just about to snap closed over a sheet 88. The closing of the gripper 88 is accomplished in an extremely rapid manner by reason of the sudden fall portion 80 of the cam 14 allowing the roller 12 to swing downwardly as viewed in Figure 3 to the normal closed position of the grippers 88 and a position in which the roller 12 and the cam 82 are entirely free of mechanism contacting same.

A sheet 88 of paper or other material is held upon a clip bar either" or 88 between the grippers 88 and the enlarged heads 8| of the pins the movement of the with the chains 48 clip bar as the same moves and 4| so that said sheet 88 passes between the tionary cam bar therefor, changes its horizontal direction of travel about the sprockets 43 and travels upwardly to be acted upon 'by the clip loading mechanism as has been described above.

' Turning now to the first embodiment of the clip bar loading mechanism illustrated in Figures 2, 3, land 5, the structure utilized for securing accurate registration of the sheets 88 within the clip bars 48 and 80 will be described. Supported by a tie-bar I01 are a pair of brackets I08 which carry. affixed to the upper surface thereof a curved paper feeding table I08. The table I08 is situated at a level to co-operate with a paper feeding device of any suitable type adapted to feed sheets of paper singly thereon from a stack. The rear edge of the paper feeding table I88 is provided with a plurality of indentations I I I0 through which the open grippers 88 may pass upwardly and rearwardly (see Figure 4). Placed between the indentations III are a plurality of smaller indentations III within which are disposed, in the lowered position thereof, a plurality of stops H2. For purposes of clarity and since they are all identical with each other, only one of the stops H2 is shown in the drawings. Stop H2 includes a body portion H8 in the form of' a collar, a rearwardly extending integral bifurcated portion H4, a spring H8 attached to the rear ends of portion H4, and a pivotally mounted finger H8. The linger H8 is pivotally mounted at the upper end thereof on a short pin I I1 which is trunnioned within the bifurcated portion H4. As best seen in Figure 2, finger H8 may be rotatably adjusted within narrow limits from falling between portion I by a set screw H8 and lock nuttherefor which is threadedly mounted in a downwardb extending projection H8 integrally extending from body I8. Body portion H2 is mounted upon a transverse shaft I20 and secured thereto by a set screw I2l which is journalled in the frame plates 21 and 22 and is provided at the right end thereof with a short crank arm I22 having a horizontally projecting pin I28 which engagu a bar, by a plurality notch I24 in a reciprocable sliding bar I25. .Bar I25 at the rear end thereof is provided with a roller I25'adapted to coact with a plate cam I21 which is fixedly mounted upon the shaft 23. Bar I25 is mounted for substantially horizontal oscillation by means of a hollow guiding block I28 which is affixed to the inner surface of the frame plate 22. The inner surface of guide block I28 is provided with a pin I29 which seryes as a stationary mounting for the rear end of a coil spring 330, the forward end of which is connected to a pin Isl affixed to the bar I25. Since the pin I3I acts also as a stop in striking against th forward end of the block are, the roller I26 is enabled to coact with only the upper portion of the cam I2? which includes a low dwell I 32, a rise i355 and a high dwell I3 5.

By the structure just described, the finger IIB takes three positions during a cycle, that is, during a complete revolution of the drum 263, or during the feeding and printing of one sheet 39. The first position is an inactive position when th pin iZ-ZI contacts the block I28. The second or'registering position is when the roller I26 is riding upon the low dwell I32. In this position the finger I I6 is moved rearwardly by the action of the cam I27 a predetermined amount, yet the exact and final positioning of the finger I It may be secured by manipulation'of the set screw H8. The set screw I2I is used mainly for transverse adjustment of the finger IIB. As soon as the grippers 59 have closed upon the sheet 39 and have securely clamped the same upon th clip bar, the finger H5 is rapidly arcuately retracted to the rear of the machine by the rise I33, so

that the finger 6' does not interfere in any way with the subsequent feeding of the sheet 39 and the movement of the clip bars. The finger H6 is held in the retracted position by the high dwell I34 until it is necessary that the finger I IG-be loweredto perform another registering operation. In the embodiment just described, it will be noticed that inasmuch as there are two clip bars 49 and 50 being transported by the chains 40 and M and there is only one cam I2I,

there is only one registering position which is applied to each of the clip bars.

In a printing machine of the type herein described adapted to operate at high speed, it is imperative that accurate registration occur at all times, and while th mechanism just described hereinabove is suitable for some classes of work, as for example where the registration "need only be relatively exact with relation to the paper edge, a requirement in the case of single color printing, where it is desired to place mo'rethan one impression on the same sheet in exact registration as in color work, it is necessary that each sheet be individually registered within its respective clip bar as the clip bars are loaded. The second embodiment of the clip bar registering structure accomplishes that purpose and is illustrated in Figures 5, 6 and 8.

Since each of the clip bars 49, and 50 are closed by the action of springs 'II it is practically impossible to get the tension of the springs on each of the clips to exactly the same value and as the machine operatespt a rapid speed, the speed of the, closing of the grippers 59 is atfected by the tension value of the springs II after the cams I4 and I5 release the rollers I2 and 13. The structure described with regard to the stops H2 and their mounting upon th shaft I20 is the the first, so that in the second embodiment the cam I21 and the bar I25 are supplanted "by different structure. The shaft 23 (see Figure 6) is provided with a pinion I fixedly mounted thereon which meshes with a gear I35 fixedly mounted upon a short shaft I31 which is journalled at the irmer end thereof in a bracket I 39 affixed to the frame plate 22 by means of the bolts I39, while the outer end thereof is Journailed in the frame plate 22. The action of the pinion I35 and the gear I36 is to reduce the speed of the shaft I31 so that the same revolves at a speed one-half of the speed of revolutiton of shaft 23. Mounted upon the shaft I31 are a pair of cams MII and MI. Cams I40 and MI have low dwell portions I42 and I 43, rise portions I44 and I65, and high dwell portions I85 and I41, respectively. A pair of reciprocable sliding bars Hit and H19 are adapted to coact with cams I 40- and MI respectively, and have attached to the rear ends thereof rollers I and ISI, downwardly extending lugs I52 and I553, pins I5 3 and I55 adjacent the forward ends thereof, and vertically upwardly projecting pins its and I5? respectively.- The pins its and It! are resiliently connected to the frame plate 22 by means of coil springs I58 and I59 which have th forward ends thereof attached, to the pins I 56 and I57 and have the rear ends thereof attached to the pins I96 and IGI which project horizontally inwardly from the frame plate 22. The action of the springs I58 and I 59 is to urge the bars I48 and I49 rearwardly so that the rollers I50 and I5I coact with the cams I40 and HI. Thebars I49 and I49 are adapted for horizontal reciproca- 'Justable set screw I68 and I59 and lock nut therefor which are adapted to coact with the lugs I52 and I53. The low dwell portions I42 and I43 are adapted to allow the bars I49 and I49 to move rearwardly, together-with the lugs I52 and I59 respectively, which allows two independently adjustable positions for the shaft I20 at the time when a sheet 39 is registered or located for each of the clip bars 49 and 50, while the high dwell portions I46 and I41 move the bars I48 and I49 forwardly, thereby moving the stops II2 out of the way of the sheets 99 as advanced by the clip bars 49 and 50. The pins I54 and I55 serve as stops to prevent the springs I59 and I59 from moving the bars I48 and I49 too far rearwardly when the cams I40 and I are in positions whereby the rollers I50 and I5I are same in the case of the second embodiment as in not acted upon by said cams. It may'now be seenthat absolute registration may be obtained by the present invention for each individual sheet as the same is placed in position to be.

gripped by the clip bars and printed, making the present invention especially adapted for high speed multi-color lithographic printing.

' The relation of the various parts-may be manually adjusted by means of a hand wheel I10 (see Figure 1.) which is mounted upon a shaft III Journalled between'frame'plates 2I and 22 which carries thereon a gear adapted to mesh with the gear 21. Power is supplied to the printing machine "in any suitable manner, as for example by the sprocket chains I12 and I13 and sprockets not specifically shown on the shaft I02 and a motor I I4 as is'well understood by those versed in the art to which the present invention relates. s

I have disclosed an onset-lithographic printing machine being adapted for continuous feed at high speed and in which absolute registration is provided at two important points in the operation cycle, one at the inception of the gripping or grasping by the link chain carrier of each individual sheet, and another at the initiation of the printing operation. that is, when the sheet is compressed between the large drum carrying the lithographic sheet and the first sheet supporting portion in the small drum having the i oifset rubber blanket thereon. As is well known after being printed are drawn rearwardly in the machine and inverted and released to form a stack with th printing thereon face uppermost so that the accuracy and quality of theprinting may be checked up while the rnachineis in operation.

The foregoing description has been made rather detailed for clearness and understanding only, and no unnecessary limitations should be understood-therefrom, but the appended claims should be construed as broadly as permissible in view oithe prior art.

Iclaim': I g

1. A printing machine comprising rotary printing means including a cylinder adapted to progressively place a printed impression on a moving sheet along a certain printing line parallel to the axis of said cylinder, said line'being stationary with relation to. the periphery of said cylinder andsaid moving sheet; a continuous moving conveyer approaching said printing line along a first rectilinear path of travel substantially tangential at the printing line to said cylinder and leaving said line along a second rectilinear path or travel substantially tangential at said printing line to said cylinder; sheet gripping means on the conveyer adapted to grasp the leading edge of said sheet; registering means,

ing means including a printing cylinder and a paper supporting cylinder, said cylinders being parallel mounted and adapted to compress a moving sheet between them whereby the printing cylinder may progressively place a printed impression on said sheet along a certain stationary printing line disposed parallel to the axes of said cylinders at the point of their greatest proximity: a continuous moving conveyer approaching said printing line along a first rectilinear path of travel substantially tangential to said cylinders at the printing line, and leaving said line along a second rectilinear path of travel substantially tangent to said cylinders at the printing line;

sheet gripping means on the conveyer adapted to engage the leading edge of said sheet; registering means associated with the printing cylinder adapted to engage the gripping means for alignassociated with said cylinder, adapted to engage the gripping means for aligning same in predetermined relation with said cylinder at the inception of the printing operation on said sheet, said registering means and said gripping means becoming disengaged immediately thereafter by reason of the second tangential path of travel or the conveyer.

2. A printing machine comprising rotary printing same in predetermined relation with the printing cylinder at the inception of the placing of a printed impression on said sheet, said registering means and said gripping means becoming disengaged immediately thereafter because of the second tangential path of travel of the conveyer.

3. A printing machine comprising rotary printing means; a continuous conveyer; sheet gripping, means on the conveyer; a rotating disc having a V-shaped indentation in the periphery thereof, said disc being disposed adjacent the rotary printing means; the peripheral speeds of the printing means and the disc being in synchronism with the speed of travel of the movable conveyer: a corresponding V-shaped block portion of said gripping means being adapted for engagement within the indentation on the disc at the inception of the printing operation whereby a sheet on said gripping means is brought into a predetermined registration with relation to the rotary printing means.

4. A printing machine comprising rotary printingmeans; a feeding table; acontinuous conveyer; sheet gripping means on the conveyer; a rotating disc independent and spaced from said rotary printing means, having an indentation in the peripheryv thereof, said disc being disposed adjacent the vfeeding table; actuating means moving in a direction opposite to the path of travel of the conveyer for operating the sheet gripping means; the peripheral speeds of the printing means and the disc being in synchronism with the speed of travel of the movable conveyer and with the actuating means; a portion of said gripping means being adapted for engagement within the indentation on the disc while a sheet is being loaded into the grippin means and while the said actuating means is functioning whereby said sheet is gripped within the gripping means in a predetermined position or registration with relation to said gripping means.-

ROY ABERLE.

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