The present invention refers to a method for tightening an embossing plate ring on a chuck of a rotary embossing press, wherein the chuck is intended to be connected to heating means for leading the ring to its working temperature. The invention may be used in a rotary press such as the press disclosed in U.S. application Ser. No. 10/643,615, which is U.S. Publication No. U.S. 2004/0035305 A1, incorporated by reference.
The fastening of hot processing embossing plates, which are heated by thermic transfer from the chuck of a rotary embossing press on which the embossing plates are fastened, causes problems that are not easily solvable and known solutions show various drawbacks. Fastening the embossing plates with screws has a drawback that the screws fastened into the chuck wall, where the wall is heated through an oil circulation, require that the holes obturated by screws should not extend through the wall of the chuck. Moreover, such an operation requires time. To overcome the problem due to this fastening method, one has already thought of enclosing the chuck with a honeycomb structure into which the embossing plates can easily be secured in the requested position.
On the one hand, that solution enables eliminating the screws and makes it easier to fasten the embossing plates. But, on the other hand, it strongly penalizes the thermic transfer between the heated chuck and the embossing plates, insofar as it greatly reduces the thermic transferring surface between the chuck and the embossing plates. This is a relatively important drawback related to the rotary embossing press capacities.
USPTO Backgrounds
USPTO Backgrounds