Printing – Inkers – Roller
Reexamination Certificate
2000-11-29
2003-07-29
Eickholt, Eugene H. (Department: 2854)
Printing
Inkers
Roller
C101S365000
Reexamination Certificate
active
06598525
ABSTRACT:
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a device for sealing off an ink supply, such as an ink duct or fountain, on printing machines, whether the latter are web-fed or sheet-fed printing machines.
The published European Patent Document EP 0 812 687 A2 discloses an ink fountain for printing machines and a method of operating a printing machine. The improvement described therein is concerned with sealing off the side surfaces of an ink fountain provided at an ink-fountain roller of an inking unit operating in accordance with the anilox principle, for example. Arranged at the ink fountain is the ink-fountain roller, against which an inking chamber is set, which is bounded or defined by two doctor blades. The two doctor blades are a metering doctor blade and a doctor blade that removes contaminants, both being accommodated on the end surfaces bounding the inking chamber. The end surfaces which bound the inking chamber and accommodate the metering doctor blade and the doctor blade that removes the contaminants are all supported on the ink-fountain roller. In the construction disclosed in the aforementioned European Patent Document EP 0 812 687 A2, a first pressure is exerted upon the ink-fountain roller by the end surface, and a second, higher pressure is exerted upon the metering doctor blade and the doctor blade that removes the contaminants. In addition, recesses are provided in the end surfaces and are closed by a circumferential closed bridge or stud, in order to produce a great local stiffness at the doctor clamping locations than at the roller surface.
The published German Patent Document DE 34 08 183 C1 discloses an ink fountain for printing machines, having a lower part forming an ink knife. This ink knife can be adjusted with respect to the ink-fountain roller, the ink supply being located between the lower part and the ink-fountain roller, and being bounded at both ends by ink-fountain jaws which seal off the ink fountain with respect to the circumferential or jacket surface of the ink-fountain roller by a sealing surface. The ink that emerges as a result of leakage losses is fed back to the ink supply again, whereby contamination of the inking unit is avoided. For this purpose, on the ink-fountain jaws, more specifically on the respective sealing surfaces thereof facing towards the ink-fountain roller, a contact surface is formed, which covers part of the width of the ink-fountain jaw and extends obliquely with respect to the latter, so that the lower end of the contact surface is directed towards the inner side of the ink fountain. In addition to the formation of a contact surface that extends obliquely to the ink-fountain jaw, this contact surface can also be formed to extend spirally.
The sealing action of the contact surface disclosed in t5he aforementioned German Patent Document DE 34 08 183 C1 depends mainly upon the manufacturing precision of the ink-fountain jaws, and also upon the positioning accuracy thereof relative to the ink-fountain roller. A deviation in the curvature of the ink-fountain jaw and the ink-fountain roller remains, because of manufacturing tolerances which inevitably occur. The resilient elastomeric material used for the ink-fountain jaws is subject to moisture and temperature fluctuations, to which the printing machine is subjected relative to a wide range of production conditions. The dimensional stability of a synthetic material is not ensured under these environmental influences. Consequently, in spite of an initially functioning sealing action, leaks at the ink fountain can occur over the course of operation of the printing machine.
French Patent 2 734 51.2 has disclosed a further ink fountain for a printing machine, wherein the ink-fountain jaws are likewise set against the ink-fountain roller surface by an adjusting device in order to achieve a sealing action. By using the aforementioned adjusting device, determined inaccuracies which result during the manufacture of the ink-fountain jaws are intended to be compensated for. The contact surface of the ink-fountain jaws on the ink-fountain roller should extend cylindrically in order to ensure continuous contact around the surface of the ink-fountain roller. With the construction disclosed by French Patent 2 734 512, the cylindricity of the contact surfaces cannot be maintained, because, with this construction, only part of the surface curvature of the contact surface of the ink-fountain jaw is deformed. It is therefore not possible for an optimum sealing action to be achieved by using the construction disclosed in French Patent 2 734 512.
SUMMARY OF THE INVENTION
Starting from the outlined state of the prior art, it is an object of the invention to provide a device for sealing off an ink supply in printing machines, which effectively ensures the sealing off of an ink-accepting reservoir during all operating phases of a printing machine.
With the foregoing and other objects in view, there is provided, in accordance with one aspect of the invention, a device for receiving an ink supply in an ink feed device in an inking unit of a printing machine, the ink supply being received in a reservoir having elements formed with laterally bounding surfaces, and contact surfaces for sealing off the ink supply with respect to a rotating surface, comprising unipartite side parts, respectively, constituting the elements formed with the bounding surfaces and the contact surfaces, the contact surfaces being engageable with respective contact areas on an ink-fountain roller formed with the rotating surface, said side parts having lip-shaped sealing elements bearing resiliently on the ink-fountain roller.
In accordance with another feature of the invention, the sealing elements are formed with free spaces extending therebehind.
In accordance with a further feature of the invention, the free spaces, respectively, follow a course corresponding to the course of a curvature of the respective sealing elements.
In accordance with an added feature of the invention, the sealing elements, respectively, are formed with a contact surface by which they are seated on an ink knife.
In accordance with an additional feature of the invention, the sealing elements, respectively, have cross-sectional courses tapering towards the contact surfaces, respectively.
In accordance with yet another feature of the invention, the sealing elements of the side parts are formed with rounded contours.
In accordance with yet a further feature of the invention, the sealing elements are resilient.
In accordance with yet an added feature of the invention, one of the side parts functions as a dividing element between two ink supplies.
In accordance with yet an additional feature of the invention, the one side part has a sealing element with a double lip formed with continuously tapering areas extending from a web, and having a decreasing cross-sectional course.
In accordance with another aspect of the invention, there is provided an ink fountain in an inking unit of a printing machine, for receiving an ink supply in a reservoir having elements formed with laterally bounding surfaces, and contact surfaces for sealing off the ink supply with respect to a rotating surface, comprising unipartite side parts, respectively, constituting the elements formed with the bounding surfaces and the contact surfaces, the contact surfaces being engageable with respective contact areas on an ink-fountain roller formed with the rotating surface, the side parts having lip-shaped sealing elements bearing resiliently on the ink-fountain roller.
In accordance with a further aspect of the invention, there is provided an inking unit of a printing machine having a device for receiving an ink supply, the device being formed with laterally bounding surfaces, and contact surfaces for sealing off the ink supply with respect to a rotating surface, comprising unipartite side parts formed with the bounding surfaces, and the contact surfaces, the contact surfaces being engageable with respective contact areas on an ink-fountain roller forme
Eickholt Eugene H.
Greenberg Laurence A.
Heidelberger Druckmaschinen AG
Locher Ralph E.
Stemer Werner H.
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