US1962156A - Inking device for rotary printing presses - Google Patents

Description

' Patented June 12, 1934.

INKING DEVICE FOR ROTARY PRINTING PRESSES- George S. Rowell, Cleveland, Ohio, asslgnor to Multigraph Company, Wilmington, DeL, a corporation of Delaware Application December 14, 1931, Serial No. 580,798

15 Claims. (01. 101-367) This invention is concerned with the inking of rotary printing presses having segmentalprinting forms, and more particularly with planographic presses which employ an image-carrying plate mounted about a roller with the ends of the plate extending into a gap in the roller, where the plate-securing and tensioningmeans are lo-- cated. A roller is usually supplied for conveying the ink to the plate. If such inking roller is gear-driven, it is likely to produce ghost lines or other blemishes on the plate due to inaccurate engagement of the gears. On the other hand, if the inking roller is frictionally driven, merely by contact with the plate, its speed of rotation 35 is reduced as the gap passes across the roller,

and this is liable to cause an unsatisfactory wiping action as the rotating plate on the other side of the gap again engages the roller. It is an object of my invention to avoid the objections abovenoted, and provide for a continuous rotationof the inking rollers without requiring a gear drive or alarge number of coacting rollers. I accomplish this result in a simple manner by providing an arcuate member ormembers occupying the space or spaces between the edges of the printing forms on the roller and being of"substantially the same radius as the printing surface, such arcuate member having asurface which may receive ink. This not only causes the inking roller to continue its rotation without de-. celeration as it passes across the gap between the printing regions, but also operates to redistribute ink to the roller, maintaining its surface evenly inked.

5 The arcuate member of myinvention, which has an ink-carrying surface, may perform only the function of maintaining the proper rotation'and inking action of the rollers which transfer the ink from a suitable supply to the plate. If de-' sired, however, this gap-filling member may itself supply ink to the inking rollers, and this is also a feature included within my invention.

My invention is hereinafter more fully explained in connection with the drawings, illustrating different embodiments thereof, and the essential novel features are summarized in the claims. In the drawings:-

Fig. 1 is a sectional view through the platecarrying roller of a printing machine equipped with one form of my invention adapted to supply ink to the rollers; Fig. 2 is a longitudinal axial section through the roller of Fig. 1; Fig. 3 is an enlarged cross section in a plane parallel with Fig. 1 of the ink-carrying device itself; Fig. 4 is a fragmentary radial section through the ink carisa solid. arcuate member.

rieri adjacent one end thereof; Fig. 5 is a fragmentary end view of the plate-carrying drum;

Fig. 6 is a detail of the clamping device for the ink carrier, on the plane indicated by the line 66 on Fig. 5; Fig. 7 is a perspective of a suitable bridge for the gap of the roller of Fig. 1, but which does not, of itself, supply the ink; Fig. 8 is a diagrammatic end view of a printing roller carrying two printing plates and two ink distributing plates.

The printing roller of Figs. 1 and 2 comprises a" segmental portion 10 mounted on, orformed with, end. discs 11 and 12, which aremounted on a driving shaft 15. The plate, designated 20, is shown as having one end provided with holes hooking over pins 16 rigidly carried by the drum segment. The other end of theplate has holes hooking over studs31 on a longitudinal portion of a suitable yoke 30 loosely mounted on the shaft 15 and tensioned by one or more springs 32. As shown, the springs are secured to a rod 17 mounted in the end members of the drum. This, or some equivalent construction, serves to maintain the plate taut on the drum surface 10; while the anchorages for the, ends of the plate are inside of the path of movement of thesurface of the plate.

In the gap of the cylinder 10,. between the anchorages 16 and 31 of the plate, I mount my bridge, which has an exterior surface substantially continuing the cylindricalsurface of the 5 plate. In the constructionof Figs. 1 to 4, this bridge 40 is made hollow and may operate to continue ink automatically fed to the rollers; while in the construction of Fig. '7, the bridge In either case, the arcuate surface .of the bridge is adapted to carry ink. I

Coacting with the plate 20 and with the bridge 40 or 90 area pairof ink-transfer rollers 70, preferably of rubber, each of which coacts with another roller '71 which, if desired, may be an ink-supply roller and be formed of such material as sponge-rubber, felt or otherfabric. The distance between the. two rollers 70, where they contact with the cylinder, is materially greater than the gap between the edge of the bridge and the plate 20 so that, in the rotation of the drum, one roller or the other is always in contact with either the plate or the bridge. 1 Thus, when. either 105 .roller passes the short gap between the plate engagement with the roller 70 continues to drive such lateral roller 70 at undiminished speed.

It results from the described arrangement that, while my rollers are frictionally driven, they are maintained at a constant speed and serve to ink the plate effectively so that the same may properly coact either with a transfer blanket or directly against the paper held by a suitable platen. The member in Fig. 1 is intended to indicate either a transfer roller or a platen roller, according to whether the printing is effected in the offset manner or directly.

I will first describe the ink-feeding form of my bridge illustrated in Figs. 1 to 4, inclusive. In these figures, the bridge 40 comprises a fabric covering mounted on the perforated arcuate sheet of metal 41. This sheet of metal is supported by a rectangular metal frame 42, the parallel sides of which are shown as flanged outwardly at 43 and secured to the arcuate plate in a suitable manner, as by screws or rivets. The end members 44 of the supporting frame are also parallel to each other. Within the rectangular box just provided is a movable bottom 50, the upper surface of which is preferably curved concentrically with the bridge plate 41, and the side and end edges of which carry a rubber wiper 51 which engages the side walls and end walls of the box 42. This bottom 50 is spring-pressed toward the top 41 of the box 42.

I have shown the bottom as provided with four downwardly extending pins 53 and 54. The pins 53 extend slidably through the longitudinal rod 1'7 of thedrum heretofore mentioned; while the pins 54 extend slidably through a similar longitudinal rod 18 of the drum. Suitable springs 55, surrounding the rods 53 or 54 between the frame rods and the movable bottom 50, tend to press the bottom toward the top plate 41.

Means are provided for the insertion of a supply of ink into the space within the box 42 between the movable bottom and the top plate. In Fig. 4, I have indicated at 60 a passageway from the ink space through one of the end walls 44 into a valve cavity 61. From this cavity, a passageway 62 leads to an opening in a boss 63 formed on the end plate 44. This opening is normally closed by a screw plug 64, and the connection between the cavity 62 and the cavity 61 is normally closed by a check valve, indicated by a ball 65 pressed down by a spring 66 seated against a removable plug 67.

Removal of the plug 64 allows ink to be forced into the cavity 62 and beyond the check valve and through the passageway 60 into the space above the movable bottom 50. Pressure on such ink will force down the bottom against the action of the springs 55, and then, in use, these springs, reacting, press the bottom upwardly and force the ink through the perforations of the crown plate 41 and through the fabric surface 40 so that that surface is maintained inked.

To enable the ink to be readily supplied to the ink carrier just described, I form an opening 19 in the end member 12 of the drum, which opening stands opposite the plug 64. When that plug is removed, I may screw into the threads which it had occupied the tip of a flexible tube A adapted to contain ink. By squeezing this tube in the usual manner, the plastic ink is forced into the cavity 62 and beyond the check valve 65 through the passageway 60 into the space in the hollow bridge. When the pressure on the tube is' released, the check valve 65 prevents escape of the ink from the hollow bridge, and a proper manipulation of the tube may draw back into it ink from the cavity 62 so that there is no ink escape as the tube is unscrewed from the cavity. The returned plug 64 insures against any leakage of ink from the opening during the operation of the machine.

To position the hollow bridge described accurately in the gap of the drum, I provide abutment screws 80, which are adjustably mounted in bosses 81 carried by the hubs of the end members 11 and 12. By turning these screws and locking them by their jam nuts, the position of the hollow bridge may be accurately selected; then the bridge is locked in place by cap screws 85 which pass through slots 86 in the end members of the drum into bosses 87 formed on the end walls of the bridge. This operation is illustrated in Figs.5 and 6.

While there are advantages in supplying ink to the bridge 40 so that the inking rollers may be automatically supplied; the other effect of the bridge maintaining the rollers constantly rotating may be obtained by the solid metal bridge of Fig. 7. This bridge comprises the arcuate plate 90 supported by end walls 91. These walls are shown as flanged inwardly at their bottoms as at 92 to abut the pins heretofore mentioned, which limit the innermost position of the bridge. The end walls are provided with outwardly extending bosses 94, which are internally threaded to receive the cap screws extending through the drum ends as already explained. Accordingly, this simple metal bridge may be maintained in the gap of the plate-carrying roller in the same position as the ink-supplying bridge already described; in fact, is interchangeable with it.

Figure 8 is a diagrammatic illustration of an embodiment employing two ink distributing plates and 90 having a surface similar to the bridge 90 of Fig. '7, and operating between two printing plates 20% and 20*. In such an arrangement, after the inking of each plate, the ink on the rollers is smoothed and ironed out by engagement of a distributing plate.

When the all-metal bridge of Fig. 7 or Fig. 8 is employed, it is desirable thatthe metal surface thereof be of such form that it may carry ink. Ordinarily smooth metal will not so act with certain types of ink; but a grained surface similar to a grained lithographic plate will carry most inks, or a surface treated with a proper enamel is effective for this purpose. Such a grained or enameled surface allows the employment of a supply roller '71 of the type which eliminates an ink fountain and permits the use of an ink of a rather heavy body.

By providing an ink-receptive surface, in any of the embodiments of my invention, it results that after the surface is inked, it acts on the rollers to redistribute ink thereto, and in effect to smooth or iron out the ink on the roller, preventing irregularities in the coat of ink, which might cause ghost lines" on the print.

It will be understood that the transfer cylinder with its blanket or the platen, as the case may be, will be of the same size as the printing cylinder with its plate or plates, and will be provided with a similar gap or gaps so that there will be no possibility of the ink from the bridge passing directly to the transfer blanket or paper.

My bridge, whether of the ink-supplying form or of the solid metal-plate form, is simple in construction; and is readily mounted in the drum in accurate position to coact with the inking rollers. The bridge may also be readily removed for cleaning, or if the removal is desired for more conveniently changing the printing plate. If the ink-supplying form of bridge is used, the ink tube may be very quickly attached to it, and the ink fed to the hollow bridge, without disturbing the bridge or the plate on the drum.

I claim:

1. The combination of a roller having a gap, a printing surface adapted to be carried by the roller, a bridge carried by the roller at the gap, means for radially adjusting the position of the bridge, two inking rollers each adapted to engage the printing surface and the bridge, said rollers being spaced farther apart than the distance between the edge of the bridge and the printing surface, and means for communicating motion from one roller to the other.

2. In the combination of a drum having a gap, means for securing a planographic printing plate about the same, an arcuate bridge located in the gap, and means for adjustably holding the bridge in position so that its exterior surface may form a portion of substantially the same theoretic cylinder as that bounding the printing surface of the plate.

3. The combination of a roller adapted to carry an arcuate printing surface, and having a gap, a hollow container located within said gap and having passageways from its interior to its exterior, whereby ink supplied to the interior may pass to the exterior, and an ink-transfer roller adapted to engage successively the printing surface and the surface of the ink device.

4. In the combination of a drum having a gap, means for securing a printing surface on the drum, a hollow container carried by the drum within said gap and having an arcuate surface connected by passageways with the interior of the container, means for forcing ink from the container to said arcuate surface, and means for transferring ink from said arcuate surface to the printing surface.

5. The combination of a drum having a gap, means for securing a printing surface on the drum, a hollow container located in the gap, said container having a perforated arcuate top, a movable bottom in the container spring-pressed toward the top, and means for transferring ink from the top of said container to the printing surface.

6. The combination of a drum having a gap, means for holding a printing surface thereon, a hollow container located in the gap and having a perforated arcuate surface surmounted by a fabric surface, a movable bottom in the container, maintaining an ink-tight connection with the container walls, means for pressing said bottom toward the top, means for supplying ink to the interior of the container, and a plurality of mutually connected inking rollers adapted to engage the printing surface and the fabric surface, two such rollers being located such distance apart that when one of them is at the space between the edge of the top and the printing surface the other is engaging either the printing surface or such top.

7. The combination of a movable printing member, means for securing thereon a printing plate and a non-printing plate having an inkretaining surface, the printing plate and nonprinting plate being at the same radial distance and traveling in the same path as the member moves, and an inking roller adapted to coact successively with the printing and non-printing plates, and an ink-supply roller coacting with the inking roller and adapted to deliver ink thereto.

8. The combination of a printing drum, having a gap, means for securing a printing plate thereon, a: bridge located in the gap, and having an arcuate surface carried by two radial end portions and means for securing the radial end portions to the drum.

9. The combination of means adapted to carry a printing surface and having a gap, a member located in said gap and having an internal ink carrier and having an exposed exterior surface, and a roller which may coact successively with the printing surface and ink-supply surface.

10. In the combination with a movable member for carrying a printing surface, of a hollow ink-supply device carried by said member, means whereby ink may pass from the interior of said device to the exterior, and an inking roller adapted to engage successively the printing surface and the inking device due to the movement of said movable member.

11. In the combination of a movable member carrying a printing surface, a hollow container mounted on said member and having a perforated top, a fabric covering over said top, and means for transferring ink from the fabric to the printing surface.

12. In a printing machine, the combination of a roller, a plurality of segmental printing plates thereon, ink distributing plates located on the roller between the printing plates and at the same radial distance, and an inking system having a form roller the axis of which does not move during operation, said form roller being adapted to coact alternately with the printing plates and the ink distributing plates.

13. A drum adapted to carry a printing surface, an ink container located within the drum, means to force ink from the container to the exterior of the drum, and an inking roller adapted to pick up such ink and engage the printing surface.

14. The combination of a drum adapted to carry an arcuate printing surface and having a gap, a hollow container located within the drum and having an arcuate top at the gap, means in the container adapted to press ink therein to said arcuate top, and an inking roller adapted to engage with the arcuate top and the printing surface.

15. In a printing machine, the combination of a form-carrying drum having a gap, an ink-supply device in the gap comprising a hollow container having a perforated top with a fabric covering held over the perforations and exposed at the periphery of the drum, a movable bottom in the container, springs for. pressing the bottom toward the top, and packing at the edges of the bottom for maintaining a close engagement between the bottom and the container walls.

GEORGE S. ROWELL.

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