Arrangements for securing cylinder jackets

Abstract

A jacket-securing arrangement is disclosed for mounting in a cylinder, which cylinder (220) has an outer surface and at least one recess (320) in the outer surface for receiving an inwardly turned edge of a replaceable jacket (225) overlying at least part of the outer surface of the cylinder. The jacket-securing arrangement is mountable within the recess so as not to project beyond the outer surface of the cylinder when the jacket is secured thereto, and includes a clamping lever pivotable about a shaft located within the recess between a clamping position in which the edge of the replaceable jacket is clamped between the lever and a side wall of the recess and a release position in which the lever is spaced from the side wall of the recess. A magnet is provided to retain the lever in the clamping position. The clamping lever is formed of two or more members assembled around the shaft and defining between them a bearing surface engaging an outer surface of the shaft. The shaft may be a gripper shaft including a plurality of grippers for securing a printing substrate sheet to the outer surface of a substrate transport cylinder of a printing system, the jacket-securing arrangement being disposed between grippers.

Description

[0001] Related Application Cross Reference [0002] This application claims Paris Convention priority from UK Patent Application No. 1903768.8 filed 19 March 2019, the entire contents of which are incorporated herein by reference as if fully set forth herein. technical field [0003] The present invention relates to a device and a method for securing a cylinder jacket to a cylinder, eg as used in printing systems. Background technique [0004] Printing can be divided into direct printing and indirect printing, depending on the surface on which the ink image is first deposited. In the former printing method, the ink image is deposited directly on the printing substrate, while in the latter method, the ink image is first formed on the intermediate surface. Conventional offset printing processes include lithography, flexographic printing, gravure printing and screen printing. But ink images can also be created digitally through a variety of techniques. The printing device m...

AI Technical Summary

Problems solved by technology

The latter type of indirect printing can lead to several problems such as surface wear due to repeated contact with another surface or dirt and debris that accumulates over time on the ITM and the surfaces that contact the ITM

This problem is exacerbated when relatively high pressure is applied to induce contact between different surfaces, for example the outer surface of an impression cylinder at the image transfer location may experience an increased rate of degradation

Furthermore, if the printing system performs double-sided printing, the so-called reverse transfer can lead to the transfer of dried ink and / or other undesired material from the previously printed image to the surface of the "duplex printing" impression cylinder, which Added an additional cause of performance degradation on the drum surface

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