Patent Application
20090223394
This application claims the priority, under 35 U.S.C. ยง119, of German Patent Application DE 10 2008 013 315.9, filed Mar. 10, 2008; the prior application is herewith incorporated by reference in its entirety.
The invention relates to a printing unit having an impression cylinder as well as a printing form cylinder which can be pivoted around the impression cylinder about a pivot axis running parallel to the axis of rotation of the impression cylinder. A spacing between the axes of rotation of the printing form cylinder and of the impression cylinder can be varied and the printing form cylinder and the impression cylinder can be set against each other, so that a press nip is formed in which a substrate can be printed. A first fixed-location drive for producing a rotational movement of the printing form cylinder is provided. The invention furthermore relates to a printing press having such a printing unit and a process for producing labels in a printing press.
Particularly high requirements are increasingly placed on printing presses conceived or employed for label printing or packaging printing, with regard to economy and simplicity of operation, with maximized variability for the product manufacture at the same time. For instance, such a printing press is intended to cause as few rejects as possible, for example during conversion between various print jobs, as well as between different printing processes or printing lengths. Familiar narrow web in-line printing presses constructed for label printing, in particular self-adhesive label printing, normally have a machine structure in which a printing material or a substrate is led over a large number of cylinders and rollers between various process levels (for example for printing and for drying), so that a not inconsiderably long web section is stored in the printing press and corresponding rejects can potentially arise. A label printing press that can be converted between different printing processes is described in International Publication No. WO 2005/028202 A1, corresponding to U.S. Patent Application Publication No. US 2006/0156934 A1. In order to ensure that only a comparatively short web section is stored in the printing press for a different machine structure, it is primarily a printing unit configuration that is needed, which firstly permits the desired variability in relation to printing processes and printing lengths and secondly permits a short web path.
In order to set individual cylinders on and off in a printing unit, provision is frequently made for the cylinders to be held in such a way that they can be pivoted. In German Published, Non-Prosecuted Patent Application DE 44 35 986 A1, corresponding to U.S. Pat. No. 5,690,029, an offset printing unit having a corresponding device for setting the blanket cylinder on and off is disclosed. Setting of the optimal pressure and adaptation to the printing material thickness can be achieved through the use of displacing swinging arms. For example, a printing unit with a variable printing length for offset printing is described in European Patent Application EP 1 101 611 A1, corresponding to U.S. Pat. No. 6,694,877. Bearing arms are pivoted about an axis through the use of spindle drives in order to move the axes of rotation of the printing form cylinder, of the blanket cylinder and of the impression cylinder away from one another or toward one another. Printing press cylinders and blanket cylinders of different formats can be used in the printing unit.
In UK Patent GB 1,147,778, corresponding to U.S. Pat. No. 3,443,516, an embodiment of an offset printing unit of a sheet-fed printing press is described in which, in order to set it on and off, the blanket cylinder can be pivoted through the use of a bearing arm about the axis of rotation of the printing form cylinder, and it is possible for the blanket cylinder to be raised off the printing form cylinder at the same time in a superimposed radial movement.
It is accordingly an object of the invention to provide a compact printing unit, a printing press and a process for producing labels in a printing press, which overcome the hereinafore-mentioned disadvantages of the heretofore-known devices and processes of this general type and in which a printing form cylinder can be set off the cylinders making contact with it for the purpose of format variation.
With the foregoing and other objects in view there is provided, in accordance with the invention, a printing unit, comprising an impression cylinder having an axis of rotation and a printing form cylinder having an axis of rotation. The printing form cylinder is configured to be pivoted around the impression cylinder about a pivot axis running parallel to the axis of rotation of the impression cylinder. The axes of rotation of the impression cylinder and of the printing form cylinder define a variable spacing therebetween. The impression cylinder and the printing form cylinder are configured to be set against each other to form a press nip in which a substrate can be printed. A first fixed-location drive is provided for producing a rotational movement of the printing form cylinder. A drive train connects the first drive to the printing form cylinder and the drive train includes at least one component having a torque axis running through the impression cylinder.
The torque axis has the orientation of the torque acting on the component of the drive train and runs through the point of the component at which the torque acts. Advantageously, a compact drive train for producing the rotational movement of the printing form cylinder can be implemented. The printing unit according to the invention only needs little overall space and is assembled inexpensively from a few components.
In accordance with another feature of the invention, the torque axis of the first drive and/or the pivot axis can in particular run through the impression cylinder. In other words, the torque axis of the first drive and/or the pivot axis can in particular lie within the contour of the impression cylinder, in particular intersect the body of the volume of the impression cylinder. Furthermore or alternatively, as the printing form cylinder is pivoted about the pivot axis, the impression cylinder can lie at least partly in a circular segment bounded by a line sweeping over the axis of rotation of the printing form cylinder. In other words, the printing form cylinder can be pivoted around the impression cylinder and not pivoted away from the latter. The pivot axis, as viewed from the axis of rotation of the printing form cylinder, can lie within the printing form cylinder or behind the printing form cylinder. The variation in the spacing of the axes of rotation can be carried out along a linear or straight path. In particular, an element that holds the printing form cylinder can be pivoted, and it is possible for the distance between the holder of the printing form cylinder and the pivot axis to be adjusted.
In accordance with a further feature of the invention, which is particularly advantageous for label printing, the printing unit according to the invention can be constructed to carry out a flexographic printing process or to carry out a book printing process or to carry out a gravure printing process.
In accordance with a group of advantageous embodiments of the printing unit according to the invention, the first drive is connected to the printing form cylinder through a train of gears coupled to one another by arms. The gear train in this group forms the drive train. In particular, the gear train can include first, second and third gears, of which the first gear is connected to the second gear by a first coupling arm, and the second gear is connected to the third gear by a second coupling arm.
In accordance with an added feature of the invention, in the printing unit, the torque axis of the first drive can preferably run parallel to a central cylinder axis of the impression cylinder and/or be identical to the central cylinder axis of the impression cylinder. Furthermore or alternatively, the pivot axis of the printing form cylinder can run along the central cylinder axis of the impression cylinder and/or the impression cylinder can be fixed in its location in the printing unit.
In accordance with an additional feature of the invention, in concrete terms, in the printing unit, in order to carry out a coupled pivoting movement and variation of the spacing of the printing form cylinder, a slider can be provided that can move in a slotted guide, which can be pivoted about the pivot axis, and that makes contact, with a guide cam follower connected to the printing form cylinder, against a guide cam that is fixed in its position or adjustable (in particular for fine adjustment).
In accordance with yet another feature of the invention, in an advantageous optional development of the printing unit, the impression cylinder is connected to a second fixed-location drive through another drive train. The second drive is different from the first drive. The other drive train is not identical to the drive train for the printing form cylinder. In particular, the second drive can be connected to the impression cylinder through a gear train. Furthermore or alternatively, the torque axis of the second drive can preferably run outside the impression cylinder. In addition, the first drive and/or the second drive can in each case be a servo motor.
In accordance with yet a further feature of the invention, the printing form cylinder can be held in such a way that it is connected detachably in the printing unit. The printing unit according to the invention can also have a variable format, in that printing form cylinders with different diameters can be accommodated in the printing unit. Alternatively thereto, intermediate sleeves with different diameters can be accommodated on the printing form cylinder.
With the objects of the invention in view, there is also provided a printing press, in particular a label printing press related to the concept according to the invention, comprising at least one printing unit according to the invention.
The printing press according to the invention is distinguished by at least one printing unit according to the invention having features or feature combinations according to this description. The printing press preferably has an in-line construction and/or is modular with regard to individual structural groups, in particular the printing units or printing unit groups, including their load-bearing structures. The printing press according to the invention can have a plurality of printing units, in particular four printing units for multicolor printing. The printing press can have a plurality of printing units according to the invention.
In accordance with another feature of the invention, the substrate can be in web form. In particular, the substrate can be a multilayer material web, especially a self-adhesive label material on a supporting web. The printing press can be a web-processing printing press. It can have a transport device for moving the web-like substrate through the printing press. The printing press can be a so-called narrow web printing press. The width of the web to be printed can be less than 900 mm, in particular less than 515 mm. Typical widths for embodiments of narrow web printing presses according to the invention are in particular 330 mm and 280 mm.
In accordance with a further feature of the invention, the printing press can, moreover, also have the following features, individually or in combination: a printing unit according to the invention can be held on a frame wall with the two fixed-location drives (first drive and second drive) integrated into the frame wall. The printing press can have holding elements, on which modules for different printing processes or for processing/finishing the substrate can be accommodated interchangeably in such a way that they can be connected in a detachable manner. Printing processes can be in particular: flexographic printing, gravure printing, book printing, offset printing, direct or indirect planographic printing, film embossing printing, screen printing, inkjet printing or xerographic printing. Processing can in particular be: stamping, cutting, punching out, perforating, grooving, folding or varnishing. Expressed in another way, the printing press can have a (standardized or neutral) interface, so that printing unit or processing unit components can be accommodated in such a way that they can be connected to the printing press. In particular, components that can be used through all these units or components supplementing all these units, in each case for functional serviceability, can directly be part of the printing press. The printing press can have a plurality of printing units which operate in accordance with mutually different printing processes. The order of the individually disposed printing units and/or processing units can be selected or adapted in accordance with a print job.
In accordance with an added feature of the invention, in a group of particularly preferred embodiments of printing presses, the printing unit according to the invention is held through the use of a bearing element in a load-bearing element fabricated at least partly from stone.
In accordance with an additional feature of the invention, the printing unit according to the invention can be held through the use of a bearing element in a load-bearing element fabricated at least partly from stone, in particular natural stone or a composite material having natural stone. A printing press having a load-bearing element fabricated at least partly from stone is described in German Published, Non-Prosecuted Patent Application DE 10 2006 042 884 A1, corresponding to U.S. Patent Application Publication No. US 2008/0063458, which will become known to a person skilled in the art addressed by this description of the printing unit according to the invention and the complete contents of the disclosure of which links the person skilled in the art with this description of the printing unit according to the invention. Both documents with the complete contents of the disclosure thereof are hereby incorporated by explicit reference into the disclosure of this application.
In connection with the invention, the term stone used herein is understood to mean a solid mineral mass or any individual object being formed of such material. Stone can be natural stone or artificial stone. Natural stone is a solid mineral mass produced over the course of the history of the Earth, part of the inorganic constituents of the Earth's crust or an individual object being formed of this material. Natural stone can be produced by solidification of molten minerals (basalt, granite, volcanic rocks) or loose material as a result of compaction (sandstone, limestone). Artificial stones, on the other hand, can be obtained by industrial processes.
The load-bearing element in these embodiments is formed of stone, in particular of one or more stones, preferably entirely of stone. In particular, large parts of the machine load-bearing structure or the entire machine load-bearing structure can be fabricated from stone. The entire printing unit is preferably accommodated in the load-bearing element. In some of the embodiments of the printing press according to the invention, a plurality of printing units can be accommodated in the one load-bearing element. Furthermore or alternatively to this, the machine load-bearing construction can have a plurality of load-bearing elements which are fabricated from stone. The load-bearing element or elements can be fabricated from a monobloc or a monolith. In particular, the load-bearing element fabricated from stone for the printing press according to the invention can be a base frame, a machine frame, a machine foundation, a base plate, a base unit, a printing unit frame, a printing unit lower part, a side cheek, a side wall, a side frame, a load-bearing wall, a portal support or a connecting profile.
In a first group of embodiments of the printing press according to the invention, the stone is a natural stone. In other words, the load-bearing element can be fabricated from a naturally occurring stone. In particular, the natural stone can be an igneous rock, a deep-seated rock, or a metamorphic rock. The natural stone is preferably a granite, a granite-like rock, a granite porphyry, a gneiss or a marble. In particularly advantageous embodiments, the natural stone is a black granite, a gabbro or an impala granite.
The printing unit according to the invention can also be a compact printing unit having further features as are described in German Published, Non-Prosecuted Patent Application DE 10 2007 045 876 A1, or part of a compact printing press having further features as described in German Published, Non-Prosecuted Patent Application DE 10 2007 045 876 A1. That publication will also become known to the person skilled in the art addressed by this description of the printing unit according to the invention. German Published, Non-Prosecuted Patent Application DE 10 2007 045 876 A1 with the complete contents of the disclosure thereof is hereby incorporated by explicit reference in the disclosure of this application.
With the objects of the invention in view, there is concomitantly provided a method for producing labels or self-adhesive labels in a printing press. According to the invention, a printing press having features or feature combinations according to this description is operated and processes a web-like substrate which is suitable for the production of labels or self-adhesive labels.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a printing unit, a printing press and a process for producing labels in a printing press, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
Referring now to the figures of the drawings in detail and first, particularly, to
In the illustration of the individual printing units 10 in
Another drive train 78 is provided for the rotational movement of the impression cylinder 14 in this embodiment. A drive gear 82 of the second drive 40 is disposed on a drive axis 80 of the second drive 40. A torque axis of the second drive 40 runs parallel to the axis of rotation of the impression cylinder 14 and outside the impression cylinder 14. This drive gear 82 meshes with a second intermediate gear 84, which in turn meshes with a driven gear 86 for the impression cylinder 14. The first and the second drives 38, 40 are synchronized with each other. The swinging arm 18 of the printing unit 10 has a slotted guide 88, in which a slider 90 is accommodated in such a way that it can move linearly, in order to implement a combined or correlated pivoting movement with variation of the spacing. The slider 90 presses a guide cam follower 92, connected to the printing form cylinder 12, against a guide cam 94, which is accommodated in the printing unit 10 and has a position which is adjustable for the purpose of fine adjustment. The slider 90 can be moved through the use of an actuating element 96. The linear movement of the slider 90 leads firstly to a variation in the spacing of the axes of rotation of the impression cylinder 14 and of the printing form cylinder 12 and secondly, due to the action of the guide cam, also to a pivoting movement of the printing form cylinder 12 around the impression cylinder 14 (in this regard, also see
In
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2008 013 315.9 | Mar 2008 | DE | national |
