Patent Application
20140208966
This application claims the priority, under 35 U.S.C. §119, of German Patent Application DE 10 2013 001 247.3, filed Jan. 25, 2013; the prior application is herewith incorporated by reference in its entirety.
The invention relates to a rotary embossing device for embossing flat materials such as sheets, blanks, webs of paper, cardboard, plastics and composite materials. The rotary embossing device includes a drive shaft and at least one embossing tool disposed thereon. The embossing tool has a roller body, a mounting system and a tool sleeve. The tool sleeve is mounted to the roller body by the mounting system.
Folding boxes are packages made of cardboard or corrugated board or, to a more limited extent, of plastics. Depending on their construction, glue is applied to one or more locations of such a folding box during the folding process. In general, folding boxes are produced from blanks. The blanks are usually cut out in a flat-bed or rotary die cutter. The blank needs to be folded along multiple lines and to be glued at least along one edge. The folded boxes are flat when they exit the folder-gluer and may be stacked in compact stacks or packaged in cardboard shipping boxes. The folding boxes may be erected and filled manually or automatically in a packing machine.
In addition to the folds required to produce folding boxes, further crease lines are pre-folded in the folder-gluer as a preparation of the following production step. That is done to facilitate the erection and the subsequent filling of the box.
If the folding boxes are used to package pharmaceuticals, it is mandatory for the name of the product to be written, for example embossed, onto the folding box in letters for the blind, also referred to as Braille letters. Such a requirement frequently also applies to blister packs, which also need to be embossed with Braille letters or other types of embossments.
In accordance with the prior art, the Braille letters may be embossed during the die cutting process in the die cutting machine when the blanks are being produced. However, that is a laborious process since a sheet to be cut contains multiple blanks, and for each blank, a pair of tools formed of a male tool and a female tool needs to be provided.
Alternatively, the embossment may be created in a rotary embossing device that includes two rotating embossing tools and may, for instance, be part of a folder-gluer.
Known Braille embossing devices in general are formed of an upper rotary tool, the male braille tool, and a lower rotary tool, the female Braille tool. The male Braille tool has a defined number of raised Braille embossing dots on its embossing side. The female Braille tool in general has the maximum possible number of Braille dot depressions so that it is a universally usable tool. The number of depressions or cells depends on whether the Braille embossment to be applied is based on the common 6-dot system or on the 8-dot system.
A plurality of different Braille embossments is necessary in particular for producing packaging for pharmaceuticals. For that purpose, the male Braille tool needs to be changed for every new job to be produced, requiring a plurality of male Braille tools to be kept in stock in a tool storage room.
German Utility Model DE 20 2008 017 133 U1 discloses leaving the roller bodies unchanged and only changing the tool to reduce storage requirements. The tool is attached to the circumferential surface of the roller body by magnets and is held thereon during operation by magnetic force.
German Patent Application DE 10 2010 036 011 A1, corresponding to U.S. Patent Application Publication No. 2012/0048131, discloses a tool for a rotary embossing device for embossing flat, sheet-shaped material. The device includes two rotating embossing tools in the form of a male tool and a female tool for creating the embossments. At least the male tool is formed of a roller body to which a continuous, annular tool sleeve or a slotted tool sleeve is attached. The tool sleeves are fixed by mounting systems that are described in detail. The male tool sleeve has raised embossment dots on its circumferential outer surface, in accordance with the job to be embossed. Those dots interact with corresponding depressions in the circumferential outer surface of the universal female tool.
The disadvantages of mounting systems of that type include the fact that they have high mass inertial forces, which may result in imbalances, and that they are difficult to access by a machine operator, a fact which makes changing the embossment sleeve a complex and time-consuming process.
A further disadvantage is that when two or more male embossing tools are mounted to the same drive shaft, relative synchronization between the two is impossible. However, for reasons of manufacturing tolerances, such synchronization is necessary to produce high-quality printed products. That is true in particular for meeting the legal requirements for embossing Braille letters for the blind. The prior art only discloses ways to synchronize the male embossing tool and the associated female embossing tool by rotating their drive shafts relative to each other. However, that method only allows both (or several) male embossing tools to be corrected by the same angular degree.
It is accordingly an object of the invention to provide a rotary embossing device with a mounting system and an angular adjustment, which at least partly overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and which allows easy mounting and adjustment of a tool sleeve.
With the foregoing and other objects in view there is provided, in accordance with the invention, a rotary embossing device for embossing flat or planar materials such as sheets, blanks and webs of paper, cardboard, plastics and composite materials. The rotary embossing device of the invention comprises a drive shaft and an embossing tool disposed thereon, the embossing tool including a roller body, a mounting system, and a tool sleeve, which is mounted to the roller body by the mounting system. A rotary counter-tool may be mounted to a parallel further drive shaft. In order to process the planar material, the material is transported between the two tools. In accordance with the invention, the mounting system includes at least one mounting ring disposed between the roller body and the roller sleeve and used to mount the tool sleeve. In contrast to the mounting systems of the prior art, the mounting ring has a low mass moment of inertia. Advantageously, the at least one mounting ring is in engagement with an adjustment device for rotating the at least one mounting ring to adjust the angular position of the tool sleeve about an axis of rotation of the embossing tool. Thus, the tool sleeve is likewise rotated relative to the drive shaft. The rotation is attained by a displacement of the mounting ring along the roller body surface, which is preferably cylindrical. This feature provides adjustability of the angular position of the mounting ring and thus of the tool sleeve relative to the drive shaft and thus relative to a counter-tool that may potentially be provided. If multiple embossing tools are provided on one and the same drive shaft, it is possible for the tool sleeves of the embossing tools to experience different angular adjustments and thus to be adjusted relative to each other.
In accordance with another particularly advantageous and thus preferred development of the rotary embossing device of the invention, the adjustment device in particular includes a positioning element that is movable in particular in an axial direction and is assigned an adjustment mechanism in particular disposed inside the roller body, and a groove is formed on the interior surface of the mounting ring, the positioning element being displaceable in the groove, with a displacement causing an adjustment of the mounting ring. The groove in the mounting ring is in particular aligned at an acute angle relative to the axial direction. The adjustment mechanism is easily accessible from outside the embossing tool, easily allowing the operator to adjust the mounting ring by actuating the adjustment mechanism. A further advantage is that the adjustment device has a very compact construction and has only a low moment of inertia.
In accordance with a further alternative embodiment of the rotary embossing device of the invention, the adjustment device includes a cam disc that is supported in the roller body and the rotation of which causes the mounting ring to be adjusted.
In accordance with an added alternative embodiment of the invention, the adjustment device includes a worm gear/spur gear system and the interior surface of the mounting ring has a toothing. A rotation of the worm gear is transmitted to the mounting ring by the spur gear and the toothing causes the mounting ring to be adjusted.
With the objects of the invention in view, there is also provided a rotary embossing device, in particular a rotary embossing device constructed in accordance with the above description. In accordance with the invention, the mounting system includes a mounting ring disposed between the tool body and the tool sleeve to mount the tool sleeve. The mounting ring advantageously includes at least one elastomeric ring and the mounting system further includes a mounting cover that is axially movable to compress the at least one elastomeric ring. When the at least one elastomeric ring is compressed by the mounting cover, the at least one elastomeric ring expands in the radial direction, resulting in a mounting of the tool sleeve. This construction of the rotary embossing tool advantageously provides easy mounting of the tool sleeve, in that the tool sleeve may firstly be slid onto the mounting ring and then the tool sleeve is mounted by a rotation of the mounting cover and is thus fixed to the roller body.
In accordance with another particularly advantageous and thus preferred development of the rotary device of the invention the mounting ring includes a plurality of elastomeric rings and in particular a respective stiff spacer ring between each two elastomeric rings. This allows the mounting force of the mounting system to be particularly evenly distributed and to act onto a large area of the tool sleeve to hold the tool sleeve in a particularly secure way.
In accordance with a further advantageous development at least one end of the roller body has an exterior threading and the mounting cover has a complementary interior threading to screw the mounting cover onto the roller body, fixing the mounting ring on the roller body. At the same time, screwing on the mounting cover causes the mounting cover to be axially displaced and the elastomeric ring to be compressed.
In accordance with an added feature of the invention, the elastomeric material may in particular be acrylonitrile butadiene rubber.
In accordance with a first embodiment, the tool sleeve is tubular and has a continuous circumferential surface. In accordance with an alternative second embodiment, the tool sleeve is likewise tubular, but has a slotted circumferential surface. In the second case, in accordance with a particularly advantageous embodiment, the mounting ring includes a connecting piece and the two longitudinal edges of the tool sleeve are connectible to the connecting piece, in particular in a form-locking way. The elastomeric rings and spacer rings may be fixed to the connecting piece. The groove of the adjustment device may likewise be disposed in the connecting piece. A form-locking connection is one which connects two elements together due to the shape of the elements themselves, as opposed to a force-locking connection, which locks the elements together by force external to the elements.
In accordance with a concomitant feature of the invention, the tool may advantageously be used in a Braille embossing device in a folder-gluer.
Other features which are considered as characteristic for the invention are set forth in the appended claims, noting that any combination of the described invention and the described advantageous further developments of the invention also form an advantageous further development of the invention. Further advantages and embodiments that are advantageous in structural and functional terms are set forth in the dependent claims and the description of exemplary embodiments with reference to the appended figures.
Although the invention is illustrated and described herein as embodied in a rotary embossing device with a mounting system and an angular adjustment, 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, in which corresponding elements and components are indicated by identical reference symbols and in which, for reasons of clarity, the figures are not drawn to scale.
Referring now to the figures of the drawings in detail and first, particularly, to
This device is used to receive job-dependent tool sleeves 17 having different structures which may, for instance, be provided with raised portions to create Braille dots. In the illustrated case, the tool sleeve is a slotted tool sleeve 17. This tool sleeve 17 may be slid onto the mounting ring 31 without difficulty. The longitudinal edges of the tool sleeve 17 in the region of its slot engage in specifically formed grooves of the connecting piece 34, causing the tool sleeve 17 to be fixed on the mounting ring 31. In order to ensure a secure fit of the tool sleeve 17, tension needs to be created in the mounting system 30. This is done by screwing the mounting cover 36 further onto the roller body 4. This screwing movement causes the elastomeric rings 32 to be compressed or squeezed and to expand in a radial direction. Due to the expansion of the elastomeric rings 32, the tool sleeve 17 is mounted and is securely pressure-fitted onto the roller body 4. A screwing movement s for mounting purposes is indicated by a double-headed arrow in
If an angular adjustment of the tool sleeve 17 needs to be made relative to a non-illustrated counter-tool or relative to a (non-illustrated) further rotary embossing tool 2 mounted to the shaft 12, the angular adjustment may easily be achieved by actuating the adjustment device 20. For this purpose, the adjustment device 20 includes a positioning element 21, which is pin-shaped and may be actuated by an adjustment mechanism 23. The adjustment mechanism 23 includes a threaded pin that has a hexagonal socket, for example, which is easily accessible from outside of the male tool 2. Actuation of the hexagonal socket causes the headless screw to be rotated. The positioning element 21 has a matching interior threading and is displaced in an axial direction by the rotation. The adjustment mechanism 23 is integrated in the roller body 4. Only a pin of the positioning element 21 protrudes from the offset circumferential surface of the roller body 4. This pin of the positioning element 21 engages in a groove 22 formed on the interior side of the connecting element 34. A groove 22 (indicated by a dashed line in
| Number | Date | Country | Kind |
|---|---|---|---|
| 102013001247.3 | Jan 2013 | DE | national |
