US2338878A - Means for supporting the masks in printing rollers - Google Patents

Description

Jan. 31, 1944. 2,338,878

MEANS FOR SUPPORTING THE MASK IN A PRINTING ROLLER F. A. STEAD Filed Jui 26, 1941' 2 Sheets-Sheet 1 IN VEN TOR ATTORNEY Jan. 11, 1944. F, A. STEA'D MEANS FOR SUPPORTING THE MASK IN A PRINTING ROLLER 2 Sheets-Sheet 2 Filed July 26, 1941 a) INVENTOR ATTORNEY Patented Jan. 11, 1944 UNITED STATES PATENT OFFICE MEANS FOR SUPPORTING THE MASKS IN PRINTING ROLLERS Frank A. Stead, Rye, N. Y., assignor to Linotone Corporation, a corporation of New York Claims.

This invention relates to roller printing machines of the so-called step and repeat type commonly used in the photomechanical production of a design on a printing roller.

In accordance with one well known method of producing a design on such a roller, a positive of a unit portion of the design is created photographically on a flexible film, and after the roller has been coated with a light sensitive emulsion, the image bearing portion of the positive is brought into contact with the sensitized surface of the roller and then subjected to the action of light during which those areas of the sensitized surface underlying the opaque reproduction of the design element on the positive remain unaffected by light whereas those areas of the sensitized surface underlying the transparent areas which define the design element on the positive become affected by light. Thereafter, the image bearing portion of the positive is carried out of contact with the sensitized surface of the roller and the relative positions of the positive and roller are changed either longitudinally or circumferentially after which the image bearing portion of the positive is again brought into contact with the sensitized surface of the roller and subjected to the action of light to create a second reproduction of the design element on the sensitized surface of the roller in the form of light unaffected areas bounded by light affected areas. In like manner, additional reproductions of the design element are created along and about the sensitized roller to cover that portion thereof from which it is desired to print with reproductions of the design element. Thereafter, the coating on the roller is developed to fix those areas of the coating effected by light, and then Washed to remove those areas of the coatin which remained unaffected by light and which are reproductions of the design element, and finally, the roller is subjected to the action of acid to etch out the areas thus bared and so form in intaglio reproductions of the design element.

In many instances, it is desirable that the several reproductions of a design element thus created about and along the roller bear a predetermined relationship with respect to one another. For example, when it is desired to print an endless pattern, the several reproductions of the design element created about and along the roller should interfit along their edges.

While with present arrangements it is a comparatively simple matter to accurately control the required change in the relative positions of the positive and roller between the successive reproducing operations, considerable dimculty has heretofore been experienced in bringing the image bearing portion of the positive into the exact position it must occupy on the sensitized surface of the roller after such change has been made to insure that the reproduction of the design element created therefrom bears the intended predetermined relationship with the other reproductions of the design element created on the roller.

In accordance with the present invention, however, the above noted as well as other difiiculties are obviated by so supporting the positive that each time the image bearing portion thereof is carried into and out of contact with the sensitized surface of the roller any given point thereon travels through a fixed path. Under these conditions, the only requirement necessary to insure that the reproduction of a design element created about and around the sensitized surface'of a roller bear an intended relationship with re spect to the other reproductions is that the change which must be effected in the relative positions of the positive and the roller between successive reproducing operations be accurately controlled, and as stated hereto-fore this requirement is easily met with present machines.

For a more complete description of the invention reference may be made to the accompanying drawings wherein the invention is shown in its preferred embodiment and by way of example. Obviously, however, many changes and variations may occur to those skilled in the art which will still be comprised within the scope of the invention, and it is to be understood, therefore, that the invention is not limited to any specific form or embodiment, except in so far as such limitations are specified in the appended claims.

Referring to the drawings- Figure 1 is a sectional view taken along line 1-! of Figure 3;

Figure 2 is an end view of a machine embodying the present invention? v Figure 3 is a front'view, partly in section, of the machine shown in Figure 2;

Figure 4-. is a sectional view 44 of Figure'3;

Figure 5 is a plan view of a film carrying blanket ordinarily used with such machines;

Figure 6 is a sectional view of a portion of the film, blanket and one of the blank supporting bars which illustrates the means for connecting the blanket to the bars; and

Figure 7 is a view, partly in section, taken along line -1 of Figure 4.

In describing the invention, let it be assumed taken along line that an endless design comprising alternate rows of printing and non-printing squares which join end on end is to be produced along and about the surface of a printing roller I9. As usual in such cases, in image II of a unit portion of the design is created photographically on a flexible film I2 which is then secured to the central portion of a, flexible transparent blanket I3. Also let it be assumed that the image |I thus created on the film I2 equals in length a third of the circumference of the roll I9 and in width a third of the length of the printing surface of the roller. Under these conditions a reproduction of the image I I on the film I2 must,

be created three times about and three times along the roller II) to form an endless design thereon. To these ends, the roller I!) after being coated with a light sensitive emulsion, is mounted on a shaft I4 journaled in opening bearings I5, I9 and it is held in axial alignment therewith by means of a pair of cone-shaped members I1, I9 inserted into its ends and secured to the shaft I4. Then the blanket I3 carrying the film I2 is positioned flatwise above the roller I9 and connected at one end to a bar I9 positioned above and on one side of the roller I9 and at its other end to a sleeve 29 mounted on a rod 65 positioned above and on the other side of the roller.

The bar I9 at ends is journaled in a pair of arms '22 pivotally mounted on a shaft 24 disposed horizontally beneath the roller I9 and in axial alignment therewith, and the rod 65 carrying the sleeve 29 is journaled at its end in a like pair of arms 23 which are also pivotally mounted on the shaft 24. The arms 22, 23 being so mounted on the shaft in tend to rotate thereabout and in so doing each pair tend to separate and so maintain the blanket I3 taut above the roller I (see Figure 4). In addition, each of the arms 22, 23 is provided with a lug 25 which extends beyond the shaft 24 in bell-crank lever fashion, and a spring 26 connected to each lug and to the arm adjacent thereto tends to rotate the arm to which it is connected about the roller and so aids in maintaining the blanket I3 taut above the roller ID. The film I2 is so positioned on the blanket I3 that its longitudinal center line a'a is directly above the axis of the roller I0, and so that the blanket I3 may be adjusted laterally above the roller ill to bring this condition about it is connected at its ends to the bar I9 and to the sleeve 29 by means of hook members 2|. The blanket I3, along its ends (Figs. 5 and 6) is provided with eyelets 66 adapted to receive the curved ends of the hook members 2|. The hook members 2| that are connected to the blanket I3 at one of its ends extend through the bar I9 and they are provided at their outer end with adjusting nuts 61, and the hook members 2| that are connected to the blanket I3 at its other end extend through the sleeve member 20 and the rod 65. and they too are provided at their outer end with adjusting nuts 58. The openings in the sleeve member 29, however, through which the hook members 2| extend are elongated to permit the sleeve member 29 to be rotated for limited distances about the rod 65. Adjacent each opening in the sleeve member 29 on the outer face thereof a cam surface 69 is formed, and between the cam surfaces 69 on the sides of each opening in the sleeve member 29 and the adjusting nuts 68- on the hook members 2| a cam block I9 is interposed, the arrangement of parts being such that when the sleeve member 29 is rotated about the rod 55 the end of the blanket I3 adjacent thereto is raised or lowered with a consequent lateral displacement of the longitudinal center line a-a of the film I2 with respect to the axis of the roller I8. To give a visible and calibrated indication of the displacement thus effected, the sleeve member 29 is provided with an operating handle I2 having an indicating mark l3 formed thereon, and the rod 65 is provided with an indexing plate 14 having indicating marks 75 above which the indicating mark I3 on the handle I2 travel as the sleeve 29 is rotated. The indicating marks I5 on the plate are calibrated to accord with the displacement of the longitudinal center line 2-2 on the film as the sleeve member 29 is ro- 'tated about the rod 65. In operation, a rough adjustment in the position of the film I2 with respect to the roller I9 is effected by means of the adjustable hooks 2i, and then the final adjustment to bring the longitudinal center line a-a of the film l2 above the axis of the roller i9 is effected by rotating the sleeve member 20. After the film I 2 has been located in desired position, the sleeve member 29 is locked by means of a clamping stud it which projects outwardly therefrom through a slot IT in the indexing plate I l tailad which is provided with a take-up wing nu The shaft 2 5 on which the arms 22, 23 are rotatably mounted is secured at its ends to a pair of blocks 2?, 28 carried by a pair of rods 29, 39 slidably mounted in vertically disposed sleeve members 3|, 32 which form a part of a carriage 35 by means of which the blanket I3 and the film 12 mounted thereon may be moved along the roller ill from one fixed station to another in the manner subsequently to be described.

The shaft 24, in turn, is connected by means of an intermediate link 33 to a fore-and-aft bellcrank lever 37 pivotally mounted on a'short shaft 38 carried by a pair of lugs 39, ill which project forwardly from the front wall of the 1 carriage 35, the arrangement of parts being such wardly and upwardly to fixed stations and in a path such that its axis is always in alignment with the axis of the roller I9. When the shaft 2 reaches its upper or lower station an offcenter spring ii connected to the bell-crank lever 37 and to the lug 49 on the carriage 35 acts to hold it there in operative position.

As the shaft 24 and the arms 22, 23 move downwardly the blanket I3 carrying the film I2 also moves downwardly in flatwise condition until the image area II of the film I2 is brought into point contact with the sensitized surface of the roller Iii. During this downward travel of the film I2 the longitudinal center line a-a through the image area II thereon is always in alignment with the axis of the roller is, this being true since the film i2 was originally so located and the bar I9 and sleeve member 29 carrying the blanket I3 move straight downwardly. As the shaft 24 continues to move downwardly to its lower station after the image area i I of the film I2 has been brought into point contact with the sensitized surface of the roller 60 those portions of the image area II on opposite sides of its longitudinal center line can are simultaneously and progressively brought into engagemen-t with the sensitized surface of the roller I in wrap-around fashion, and as the image area II on the film I2 is thus brought into engagement With the sensitized surface of the roller It the arms 22, 23 carrying the bar I9 and the sleeve member 2!! to which the blanket I3 is secured rotate about the shaft 24 against the action of the springs 23 and against the action of gravity which tends to rotate them about the shaft 25 in the opposite direction.

After the image area I I of the film I2 has been thus brought into contact with the sensitized surface of the roller IE! it is subjected to the action of light from any suitable source (not shown) during which a reproduction of the image II on the film I2 is created on the sensitized surface of the roller in the manner well understood in the art.

After the reproduction of the image H on the film l2 has been created on the sensitized surface of the roller I ll the bell-crank lever 37 is rocked forwardly to raise the shaft 24 to its uppermost position as determined by the banking of adjusting nuts I9 carried by the slide rods 29, 341 against the lower ends of the sleeve members 3t, 32. As the shaft 24 travels upwardly, gravity and the action of the springs 25 act to rotate the arms 22, 23 about the shaft M with the result that those portions of the image area II of the film I2 on opposite sides of its longitudinal center line aa are progressively brought out of contact with the sensitized surface of the roller Ill. This continues until the image area i l is only in point contact with the sensitized surface of the roller ID at which time the blanket I3 is stretched fiatwise between the bar it? and the sleeve member 20 and so prevents further rotation of the arms 2|, 22. Thereafter, the bar i9 and the sleeve member 20 move straight upwardly until the shaft 24 has reached its uppermost station, and as the bar I9 and sleeve mem ber 29 move straight upwardly the image area I I of the film I2 is also carried straight upwardly in fiatwise condition and with its longitudinal center line a-a still in alignment with the axis of the roller.

After the image area H of the film I2 has been thus carried into and out of contact with the sensitized surface of the roller l0 and a reproduction of the image H on the film l2 created on the sensitized surface of the roller It), the position of the roller i0 is changed beneath the film l2 from one fixed station to another or the position of the film I2 is changed above the roller ID from one fixed station to another, the image area II of the film I2 again carried into and out of contact with the sensitized surface of the roller I Q and a second reproduction of the image II on the film I2 is created on the sensitized surface of the roller ID. In like manner, additional reproductions of the image II on the film I 2 are created along and about the sensitized surface of the roller ill until the image H on the film !2 has been reproduced three times along and three times about the sensitized surface of the roller IE! to form an endless design. Thereafter, the coatin on the roller I ll is developed to fix the light affected area, washed to remove the light unaffected areas, and finally the roller Iii is subjected to the action of acid to etch out the areas exposed by the removal of the light unafiected areas of the coating all in the manner well understood in the art.

The arrangement for moving'the film I2 above the roller I8 comprises the movable carriage heretofore referred to and which includes as a part thereof the sleeve members, the slide rods 28, 35 mounted in said sleeve members 3 i, 32, the shafta i carried by said slide 29, 39, the arms 22, 23 mounted on the shaft 24, and the bar it and the sleeve member 20 to which the blanket I3 is secured. The carriage 35 is slidalol'y mounted on the inner upstanding walls of a pair of spaced horizontally disposed U-shaped members 45, 46 which are supported on the main frame of the machine by means of a pair of beams ll, 43 and it is provided with a vertically disposed plunger it slidably mounted in a guide member 59 carried thereby. At its upper end, the plunger 49 is loosely connected to a short fore-and-aft lever 5| pivotally mounted on a shoulder screw 52 carried by the carriage member 35. Normally a spring 53 positioned about the plunger 49 between the guide member 5% and a collar 54 carried by the plunger 49 acts to the plunger 49 in a lowermost position. At its lower end, the plunger id is tapered to accord with a V-shaped groove cut in the upper faces of a series of stop members 55 secured, as by set screw 5'5, to a rail t t carried by the inner upstanding wall of the foremost U-shaped carriage supporting member 45.

In the present case where a reproduction of the design element is to be created three times along the roller it] three stop members 55 are positioned on the rail 57, one being positioned so that when the groove in its upper face engages the tapered lower end of the plunger 48 the carriage 35 is so positioned that the image area II of the film I2 on the blanket i3; is positioned directly above that end portion of the roller Ill on which it is desired to create a reproduction and the other two stop members 55 being so spaced along the rail 51 in front of the roller I t] that the distances between the centers of the V-shaped grooves are the same as the width of the image area if of the film l2 on the blanket l3. During the creation of the first reproduction of the design element along the roller Iii, the carriage 35 V is moved manually along the upstanding walls on which it rests to bring the tapered lower end of the plunger 49 above the -shaped groove in one of the stop members 55, the plunger 49 be ing held in a raised position against the action of the spring 53 during this movement of the carriage 35 by means of the lever 5i. Then the lever 5! is released whereupon the spring 53 acts to force the plunger 49 downwardly to position the tapered lower end thereof in the V-sh'aped groove and thus lock the carriage 35 in fixed position in front of the roller It]. After the first reproduction has been created along the roller It, the plunger 49 may be raised by means of the lever 5i, the carriage 35 moved manually to position the tapered lower end of the plunger 49 above the V-shaped groove in another of the blocks 55 and the lever 5! released whereupon the spring 53 will act to force the plunger 49 downwardly to position the tapered lower end thereof in the -shaped groove. In like manher the carriage 35 may be moved and the tapered lower end of the plunger 49 located in the V-shaped groove in the remaining block 55 prior to the creation of the third reproduction of the design element along the roller ll. During this travel of the carriage 35 from one fixed station to another the blanket I3 carrying the film i2 is stretched flatwise above the roller it] in which case the relative position of the image area I l of the film I2 remains fixed with respect to the carriage 35. In consequence, the reproductions created along the roller ID will interfit along their side edges to form a continuous pattern,

To the end that the roller It may be turned beneath the film i2 from one fixed station to another, the shaft M on which the roller ii] is mounted is provided with an indexing disk {iii having a number of holes ti. In the present case where three reproductions of the design element are to be created around the roller H) the disk 60 is provided with three holes Bl spaced 120 apart and so located that as the shaft l4 carrying the roller ii! is turned the holes Bl pass in front of a locking hole 62 formed in the bearing assembly 16 adjacent the disk til. During the creation of the first reproduction of the design element on the roller Hi the disk ER! is locked in fixed position by means of a pin 63 inserted through one of the indexing holes 6! and into the locking hole 52. Then when the second re-- production is to be created about the rolier Iii, the pin 63 is removed, the shaft i i turned until another hole in the disk 60 is brought opposite the locking hole 52 at which time the shaft i4 is again locked in fixed position. Under these conditions, when three reproductions of the design element are created about the roller Id the edges thereof will interfit to form a continuous design.

Having thus described my invention what I claim is:

1. In a machine for creating on a sensitized roller a reproduction of a design element on the image area of a flexible film, the combination of means for supporting said roller, a pair of bars adapted to hold said film flatwise and in spaced relation to the curved surface of said roller, and means for moving said bars in conveying and diverging fixed paths on opposite sides of said roller to carry the image area of the film into and out of contact therewith.

2. The machine set forth in claim 1 characterized in that said bars are carried by arm members pivotally mounted on a shaft positioned in axial alignment with the roller, and in that means are provided for moving said shaft towards and away from the roller in a fixed path.

3. In a machine for creating on a sensitized roller a reproduction of a design element on the image area of a flexible film, the combination of means for supporting said roller, a pair of bars adapted to hold the film fiatwise and in spaced relation to the curved surface of said roller, a shaft mounted in axial alignment with said roller, a pair of arm members pivotally mounted on said shaft and to one of said bars, a second pair of arm members pivotally mounted on said shaft and to the other of said bars, and means for moving said shaft toward and away from said roller from one station to another and in a fixed path.

4. The machine set forth in claim 3 characterized in that means are provided which tend to rotate each pair of arms about the shaft in opposite directions.

5. The machine set forth in claim 3 characterized in that means are provided for holding said shaft to the fixed station to which it has been moved.

FRANK A. STEAD.

Images