GB2127746A

GB2127746A - Process and apparatus for continuous relief printing

Info

Publication number: GB2127746A
Application number: GB08325011A
Authority: GB
Inventors: Seihachiro Shimamura
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-09-24
Filing date: 1983-09-19
Publication date: 1984-04-18
Also published as: GB8325011D0; JPS5954561A; IT8322987A0; IT1168725B; DE3333906A1; FR2533503A1

Abstract

A process and apparatus for continuous relief printing in which an extremely long sheet of paper (1), tens of meters in length, is moved in its longitudinal direction and passed through and between one or more pairs of a plate cylinder (2, 12, 22, 32) and an impression cylinder (3, 13, 23, 33) for printing. A plurality of flexible relief plates (4) having different impressions are successively fed from a plate accumulating section (5) to the plate cylinder and wound one by one around the plate cylinder in a separable manner. Thereafter, the printing of different impressions in series are continuously effected on the paper passing between the plate cylinder and the impression cylinder. After printing, the relief plates are separated one by one from the plate cylinder under the suction of a vacuum separator (15) and then returned to the plate accumulating section in preparation for the subsequent printing operation. <IMAGE>

Description

SPECIFICATION Process and apparatus for continuous relief printing This invention relates to a process and an apparatus for continuous relief printing, and more particularly to a process and an apparatus in which an extremely long sheet of paper, tens of meters in length may be printed with a series of continuous impressions in a sequential manner.

In conventional printing processes, printing machines which are generally classified, according to printing type, into three categories including platen presses, cylinder presses and rotary presses, have been employed, and two kinds of paper for printing which include paper in rolls and paper in sheets have been used. In the case where a book is to be printed by such conventional printing processes, a plate is used to print a certain number of copies of a page, and then the plate thus printed is replaced with another plate so as to print a certain number of copies of another page. Thereafter, the above procedure is repeated in succession until the remaining papers have been printed. After the completion of printing, the printed copies of the pages are gathered and put into order for bookbinding.In this case, unless the pages are arranged in good order, there arise inconveniences such as defective and/or incorrect coliation. Further, since in the conventional printing processes, the area that can be printed on is limited to a fixed amount, printing of extended material unavoidably requires follow-up work such as the joining together of separately printed sheets, thus resulting as well in an increase in the amount of work required and in a reduction in quality.

In view of the above, it is an object of the present invention to provide a novel and improved process and an apparatus for relief printing which are capable of overcoming the inconveniences mentioned above and deficiencies inherent in the prior art.

To achieve the above object, the present invention provides a process and an apparatus for relief printing in which an extremely long sheet of paper is moved in its longitudinal direction and passed through and between one or more pairs of a plate cylinder and an impression cylinder for printing, and which is characterized by successively feeding a plurality of flexible relief plates having different impressions to the plate cylinder, winding the relief plates one by one around the plate cylinder in a separable manner, and continuously effecting the printing of different impressions in series on the paper passing between the plate cylinder and the impression cylinder.

The above and other objects and features of the present invention will be more readily understood from the following detailed description of a number of preferred embodiments of the invention when seen in conjunction with the accompanying drawings.

The invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a schematic view illustrating a preferred embodiment of the present invention; Figure 2 is a schematic view of another preferred embodiment in which the arrangements of the plate accumulating section and the plate transmitting conveyor are different from those in Figure 1; and Figure 3 shows the relation between the plate cylinder and a power source.

Referring first to Figure 1, there is schematically illustrated a preferred embodiment of a relief printing machine or apparatus constructed in accordance with the principles of the present invention. In this Figure, a long sheet of paper 1 is delivered from a paper feeder 11 to be inserted between a plate cylinder 2 and an impression cylinder 3. A plurality of flexible relief plates 4, which are formed of plastic and each of which has a different impression, are accumulated in a plate accumulating section 5 and transferred therefrom one by one through a chain conveyor 6 toward and between a pulley 8 and a plate cylinder 2.In this connection, the relief plates 4 are each provided at their side edges with sprocket perforations (not shown) which are adapted to be engaged with sprockets (not shown) provided at the corresponding side edges of the conveyor 6 so as to be conveyed thereby. For a relief plate, there may be employed plastic relief plates having magnetizable segments of magnetizable plastic or a similar material embedded therein. In this case, in place of a chain belt, there by may be used a flat belt which is coated on its surface with a thin permanent magnet layer, with transmission sprockets being provided on the belt or omitted as desired. The magnetizable relief plates may or may not be formed at their side edges with sprocket perforations as desired.

Subsequently, when a relief plate is moved forward or downward in Figure 1 by means of the conveyor 6 and reaches a location at which a conveyor pulley 8, provided at one end of the conveyor 6 adjacent the plate cylinder 2, is in rolling contact with the plate cylinder 2, the sprocket perforations (not shown) are brought out of engagement with a sprocket (not shown) on the belt 6 and into engagement with guide pins (not shown) provided on the side edges of the plate cylinder 2 so that the relief plate is wound around the plate cylinder 2 for rotation therewith. With rotation of the plate cylinder 2, the relief plate as wound around the plate cylinder 2 is inked by means of ink rollers 9.

The circumferential surface of the plate cylinder 2 may be formed of divided electromagnets.

Figure 3 shows a side elvation of the plate cylinder 2 in which near the circumferential surface of the plate cylinder 2, there are implanted a plurality of electromagnetic segments M .... in circumferentially spaced relation with each other, and each of the segments M, .... . has a pair of projections 2', 2", each 2' being for connection with a positive electrode and each 2" being for a negative electrode, which extend from one end face of the plate cylinder 2 and are radially spaced from each other. An electric source 20 in the form of a disk has an arch-shaped positive electrode 20' and an arch-shaped negative electrode 20" both formed at one end face of the electric source 20 in radially spaced relation with each other.The positive and negative electrodes 20', 20" are adapted to come into or out of contact with the positive and negative projections 2', 2", respectively, of the electromagnetic segments M, .... . of the plate cylinder 2 during rotation of the latter. As the plate cylinder 2 rotates, the electromagnetic segments M, M, . . . are energized When the related positive and negative projections 2', 2" come into contact with the positive and negative electrodes 20', 20", whereas the electromagnetic segments are deenergized when the respective positive and negative projections 2', 2" break contact with the positive and negative electrodes 20', 20". In the case that the relief plate 4 is formed of magnetizable plastic, it is magnetically attracted to the surface of the plate cylinder by switching on the electromagnetic segments M, M ....In this case, since the attractive force of the electromagnetic segments M, M,... exerted on the relief plate 4 is stronger than that of the permanent magnet of the conveyor 6, the relief plate 4 is magnetically attracted from the conveyor 6 to the plate cylinder 2 for printing. The relief plate 4, after being subjected to printing operation, is separated from the plate cylinder 2 under the suction of a vacuum suction device or separator 15, which is disposed adjacent the plate cylinder 2.In the case of a plate cylinder having its surface coated with electromagnetic material, it is designed such that, when the plate cylinder is rotated or moved to a certain angular position at which the relief plate 4 is separated from the plate cylinder, the electromagnetic segments in the surface area now positioned adjacent or in a faceto-face relation to the vacuum suction device 15, are switched off so that the relief plate 4 can be readily separated from the plate cylinder under the suction of the vacuum suction device 1 5.

In this manner, a plurality of relief plates 4, successively fed from the conveyor 6 to the plate cylinder 2, are pressed for printing on the paper 1 delivered from the feeder reel 11 between the plate cylinder 2 and the impression cylinder 3, and thereafter separated from the plate cylinder by means of the separator 15. Thus, a series of consecutive pages corresponding in number to the relief plates 4 are continuously printed on a long sheet of paper 1. After the completion of printing of all the pages for a book, the relief plates 4, separated from the plate cylinder 2 in the above manner, are coilected and accumulated again in the plate accumulating section 5 in preparation for the subsequent printing of another book. Thus, the present invention is characterized in that all of the pages for a book can be continuously printed in a most efficient manner.

The above description relates to monocolor printing, but for the purpose of multicolor printing, it is necessary only to increase the number of printing units in accordance with the number of colors, each printing unit being comprised of a plate accumulating section 5, a conveyor 6, a conveyor pulley 8, inking rollers 9, a plate cylinder 2, an impression cylinder 3 and a vacuum separator 15. In this connection, it is to be noted that the embodiment as illustrated in Figure 1 is adapted for use with two-color printing, and a second color is printed by a second printing unit which includes a combination of a second plate cylinder 12 and a second impression cylinder 13.

In this Figure, although only the plate cylinder and the impression cylinder for printing the second color are shown while other components or elements are omitted, the second unit actually comprises the same equipment as that of the first unit as described above in detail. In order to print more than three colors, it is necessary only to increase the number of printing units employed in accordance with the number of colors.

In addition, if the back side of the paper 1 is to be printed, the paper 1 is reversed by means of a known reversing device 10, as shown in Figure 1, so that a first color is printed on the back side of the paper 1 by means of a third printing unit including a combination of a plate cylinder 22 and an impression cylinder 23, and then a second color is printed thereon by means of a fourth printing unit including a combination of a plate cylinder 32 and an impression cylinder 33. Thus, both the front and back sides of a long sheet of paper can be printed in two colors in a continuous manner.The paper thus printed is sent from the final printing unit to a delivery section 14 for further processing, in which there may be provided a zigzag folder for holding the paper in a zigzag manner without cutting, or a winder for winding the paper on a reel, or a sheet cutter four cutting the paper in specific lengths, or a bookbinder connected to the final printing unit, in order to process the long sheets of printed paper in accordance with the purpose of use.

It should be noted that, in the embodiment as illustrated in Figure 1 , the conveyor 6 for transmission of the relief plates 4 is so constructed as to move in a direction perpendicular to the surfaces of the relief plates accumulated in the plate accumulating section, but the relief plates in the accumulating section may be disposed parallel to the surface of the conveyor.

To summarize, according to the present invention there are provided the following remarkable advantages: it is possible to print on an extremely long sheet of paper, tens of meters in length, which has hitherto been impossible in the conventional printing processes, and the continuous changing of relief plates allows printed material having a number of pages to be printed one by one in a repeated manner so that the necessary number of copies can be produced as desired. Further, a single continuous sheet of paper can be used for printing all the pages cf a book so that such problems as defective and/or incorrect collation do not arise.

While the invention has been described and illustrated herein with reference to a number of suitable embodiments thereof, it should be obvious for those skilled in the art that these embodiments should not be construed as restricting but are merely explanatory and thus modifications and alterations can be carried out within the scope of the appended claims.

It will be understood that an apparatus according to the invention may also be used for printing by a conventional printing process described at the beginning of this specification.

Claims

1. A process for continuous relief printing wherein a long sheet of paper is moved in its longitudinal direction and passed through and between one or more pairs of a plate cylinder and an impression cylinder for printing, the process comprising the steps of: successively feeding a plurality of flexible relief plates having different impressions to said plate cylinder: winding said relief plates one by one around said plate cylinder in a separable manner; and continuously effecting the printing of different impressions in series on said paper passing between said plate cylinder and said impression cylinder.

2. An apparatus for continuous relief printing comprising in combination: a paper feeder for delivering a long sheet of paper in its longitudinal direction; one or more printing units each including a pair of a plate cylinder and an impression cylinder for rejief printing; a plurality of flexible relief plates each having different impressions and stored in a plate accumulating section; a conveyor for successively feeding said relief plates, one by one, to a first one of said printing units from said plate accumulating section; an ink supplying section for suppling ink to said plate cylinder; a vacuum separator disposed adjacent said impression cylinder for separating said relief plates from said plate cylinder; a first means provided between said relief plates and said conveyor for releasably connecting said relief plates with said conveyor; and a second means provided between said relief plates and said plate cylinder for separating said relief plates from said conveyor and then connecting said separated relief plates with said plate cylinder.

3. A process of continuous relief printing substantially as herein described with reference to the accompanying drawings.

4. An apparatus for continuous relief printing constructed, arranged and adapted to operate substantially as herein described with reference to, and as shown in, the accompanying drawings.

5. Printed matter printed by an apparatus according to Claim 2 or 4.