Printing – Rolling contact machines – Rotary
Reexamination Certificate
2002-09-26
2004-09-07
Hirshfeld, Andrew H. (Department: 2854)
Printing
Rolling contact machines
Rotary
C101S248000, C101S475000, C101S375000, C101S382100, C101S415100, C492S018000, C492S039000
Reexamination Certificate
active
06786147
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to printing presses, and more particularly to a web-fed, multicolor printing press having a plurality of printing units for printing different color images on a continuous web of paper or like printable material. Still more particularly, the invention deals with such a press wherein each plate cylinder is split into three parts, each with a lateral dimension equal to two newspaper pages, for independently carrying as many printing plates thereby concurrently to print images in transverse juxtaposition on the web. Even more particularly, the invention concerns improvements in or relating to means in such a multicolor printing press for fine, independent readjustment of both lateral and circumferential positions of the three parts of each plate cylinder with a view to exact registration of different color images on the web.
2. Description of the Prior Art
It has been known and practiced extensively to split a plate cylinder into two or more parts that are capable of both lateral and circumferential displacement relative to each other. An example is the multicolor newspaper printing press in which each plate cylinder is split into a pair of halves each having two-newspaper-page width. Japanese Patent Publication No. 59-31467 and Japanese Utility Model Publication Nos. 6-11769 and 6-38681 are hereby cited as teaching such split plate cylinders.
Japanese Patent Publication No. 59-31467 and Japanese Utility Model Publication No. 6-11769 both suggest a plate cylinder comprised of a first cylinder part having a reduced diameter core extending coaxially therefrom, and a second cylinder part of tubular shape slidably fitted over the core and having an outside diameter equal to the diameter of the first cylinder part. Adjustments are provided for independently varying the lateral and circumferential positions of the two plate cylinder parts. According to Japanese Patent Publication No. 59-31467, the lateral and circumferential adjustments for the two cylinder parts are both disposed outside the pair of confronting framing walls between which the split plate cylinder is supported. Japanese Utility Model Publication No. 6-11769 differs in providing the lateral and circumferential adjustments for one plate cylinder part on the outside of one framing wall, and those for the other plate cylinder part on the inside of the same framing wall.
Japanese Utility Model Publication No. 6-38681 teaches a plate cylinder comprised of a pair of halves of tubular shape, both slidably mounted on a core of cylindrical shape. The lateral and circumferential adjustments for one plate cylinder half are provided on the outside of one framing wall, and those for the other plate cylinder half on the outside of the other framing wall. Driving torque is first transmitted to the core and thence to the pair of tubular halves, in order that the three constituent parts may be jointly rotatable, and that the pair of tubular halves may be independently adjustable circumferentially.
The three foregoing citations are alike in teaching two-part plate cylinders but silent on the division of a plate cylinder into three. Japanese Utility Model Publication No. 6-11769 in particular has an additional problem arising from the placement of all the lateral and circumferential adjustments for the two plate cylinder parts in the neighborhood of one of the pair of framing walls. As one lateral, and one circumferential, adjustment are positioned on the inside of that one framing wall, the distance between the two framing walls must of necessity be much longer than in the absence of such adjustments. The long span between the walls has made it necessary to provide a plate cylinder having a pair of correspondingly elongate trunnions, which of course are much slender than the plate cylinder itself. The plate cylinder has therefore been easy to sag under its own weight, with consequent difficulties in lateral and circumferential displacement of the two plate cylinder parts due to a rise in frictional resistance.
It has also been known to split a plate cylinder into four parts, each one newspaper page wide, as disclosed for example in Japanese Patent No. 2,726,716. The four-part plate cylinder comprises a solid cylinder part which has one or two newspaper pages width and which has rod-like cores of smaller diameter extending coaxially therefrom, and hollow cylinder parts which are each one or two newspaper pages wide and which are slidably mounted to the cores. Lateral and circumferential adjustments are provided for each of the solid and hollow plate cylinder parts. The adjustments for the solid plate cylinder part lie on the outside of one of the pair of framing walls, and those for each hollow plate cylinder part on the outside of that one of the pair of framing walls which is closer to that hollow plate cylinder part. Where two lateral, and two circumferential, adjustments are provided, the lateral adjustment for the plate cylinder part located centrally of the plate cylinder is mounted to the bearing sleeve supporting the plate cylinder, and the circumferential adjustment for that plate cylinder part is mounted to the blanket cylinder adjoining the plate cylinder in question.
An objection to this prior art four-part plate cylinder is the extreme complexity of the lateral and circumferential adjustments. Another serious disadvantage is that the lateral displacement of the solid plate cylinder part causes simultaneous displacement of a helical gear constituting a part of the drive linkage to that plate cylinder part, resulting in simultaneous angular displacement of the plate cylinder part by reason of the twisted gear teeth. Lateral displacement has thus been not independent of circumferential displacement.
Attempts have been made in recent years to make plate cylinders greater in diameter or length with a view to higher production, aside from an increase in printing speed. Japanese Unexamined Patent Publication No. 9-141826 represents an example of such conventional attempts at longer plate cylinders. It is not disclosed, however, to divide such a long plate cylinder into several parts that are independently displaceable both laterally and circumferentially.
SUMMARY OF THE INVENTION
The present invention has it as an object to provide a three-part plate cylinder for use in a web-fed, multicolor offset printing press or the like, so made that the three plate cylinder parts are independently adjustable both laterally and circumferentially for registration.
Another object of the invention is to make the three-part plate cylinder itself and the lateral and circumferential adjustments therefor as simple, compact and inexpensive as feasible in construction.
Still another object of the invention is to arrange the lateral and circumferential arrangements in such a manner that the span between the pair of confronting framing walls is kept at a minimum in order to prevent the three-part plate cylinder from sagging under its own weight.
Briefly, the present invention concerns, in a web-fed printing press having a series of printing units for printing images on a continuous web of paper or like material, a three-part plate cylinder apparatus included in each printing unit. The three-part plate cylinder apparatus comprises a plate cylinder which is rotatably supported between a pair of spaced-apart framing walls or like means and which is split into three. The three parts of the plate cylinder are capable of displacement both laterally and circumferentially independently of one another for registration. Drive means are coupled to the three parts of the plate cylinder for jointly driving them during printing. Also included are lateral adjustment means which are mounted outside the framing means and which are coupled to the three parts of the plate cylinder for causing lateral displacement of each part independently of the other parts, and circumferential adjustment means which are mounted outside the framing means and which are coupled to the three parts of the plate cylin
Shiba Noriyuki
Tomita Yuko
Crenshaw Marvin P.
Kabushiki Kaisha Tokyo Kikai Seisakusho
Rader & Fishman & Grauer, PLLC
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