Patent Application
20090114071
This invention relates in general to a rotating stamping apparatus for stamping blanks.
In many technical fields, stamped components of a defined size are required, which are made of materials like glass, ceramic or carbon material. For producing fibers comprising a defined length, suitable industrial methods and apparatuses have been developed. Thus, U.S. Pat. No. 4,638,934 discloses an apparatus for cutting fiberglass mats into small pieces. For this purpose, the fiberglass mats are initially cut into longitudinal strips by the rolling knives. The longitudinal strips are subsequently cut in a transversal direction. During the cutting processes, the fiberglass mat rests on an elastic cutting surface.
U.S. Pat. No. 3,921,874 describes another method and a suitable apparatus. In this publication, long threads of base material are submerged in a liquid, which is subsequently solidified through cooling. The frozen fiber strand is subsequently cut in transversal direction. After cooling and removing the liquid, short fibers are provided.
The disadvantage of the known method and apparatus is that a slippage can occur between the first and the second cutting process, so that the finished product can have different lengths. The method disclosed in the second U.S. publication furthermore only has a limited capacity and is thus less suitable for mass production.
The genus defining document DE 203 06 090 U1 describes an apparatus for rotating stamping of stamped pieces from extruded endless profiles, in particular for embossing and punching of endless profiles coming out of an extruder, wherein, however, stamping residuals are left over, which limit the productivity of the process.
This invention relates to an apparatus for rotational stamping of blanks with a defined geometry and size from a flat material. The apparatus comprises a tool that comprises plural cutting dies and cutting holes. A first tool support rotates about a first axis and a second tool support rotates about a second axis. The first axis and the second axis are disposed in parallel and at a radial distance from one another, so that a radial offset for forming a pass-through gap for the flat material is provided between the first tool support and the second tool support. The cutting dies penetrate the cutting holes fitting through counteracting rotation of the tool supports. The cutting dies and the cutting holes are disposed on the circumference of the first tool support and on the circumference of the second tool support in a seamless and alternating pattern, so that the flat material is processed into stamped blanks in a single step without lost or scrap pieces.
Various advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.
Embodiments of the invention are described in more detail in the subsequent description with reference to the drawing figures, wherein:
Referring now to the drawings, there is illustrated in
The apparatus 1 comprises a tool 8, comprising plural cutting dies 4 and cutting holes 6, wherein the tool comprises a first tool support 12 rotating about a first axis 10, wherein the tool support is configured as a drum, and the tool comprises a second tool support 16, which is also drum shaped and rotates about a second axis 14. Thus, the first axis 10 and the second axis 14 are parallel, co-planar and disposed with a radial offset from one another, so that a radial offset for forming a pass-through gap 18 for the flat material 2 is provided between the first tool support 12 and the second tool support 16 and the cutting dies 4 penetrate the cutting holes 6, precisely fitting through the counteracting rotation of the two tool supports 12, 16 similar to gears meshing with one another.
When the cutting dies 4 penetrate the cutting holes 6, a stamped blank 20, which corresponds to the cross section of the cutting die 4 or of the corresponding cutting hole 6, is stamped out of the flat material 2 and pressed into the cutting hole 6, wherein a friction locking between the rim of the stamped blank and the wall of the cutting hole occurs, depending on the tolerances and the elastic properties of the material of the flat material, wherein the friction locking tends to hold the stamped blank 20 in the cutting hole 6.
In a particularly preferred manner, the cutting dies 4 and the cutting holes 6 are configured, so that only stamped blanks 20 with identical geometry and size are stamped out, thus e.g. rectangular stamped blanks. As can be seen from
The tool supports 12, 16 each carry respective identical annular ribs 22 with cutting dies 4 and cutting holes, configured at their circumference in a seamless and alternating pattern, wherein the annular ribs are stacked in axial direction and respectively offset in circumferential direction by a pitch, so that cutting dies and cutting holes 6 also alternate in a seamless pattern in axial direction. The thickness of the annular ribs 22 thus is identical to the width of the stamped blanks 20. For reasons of clarity, the sectional view of
The annular ribs 22 are preferably comprised of steel, which is hardened or case hardened or provided with a wear resistant layer, e.g. made of hard metal, in particular in the portions of the cutting dies 4 and/or of the cutting holes 6. Due to their wear resistance, ceramic materials can be used for the annular ribs 22, e.g. in the form of a coating in the portion of the cutting dies 4 and/or of the cutting holes 6.
In a particularly preferred manner, the channels 24 extend from the inner circumference of the annular ribs 22 into the cutting holes 6.
According to a variant shown on the right side of
For radial actuation of the ejectors 26, the roller 34 is eccentrically supported at a fixed axle 36 in the interior of the rotating tool support 12 according to the embodiment on the right side of
According to another embodiment according to
According to another embodiment illustrated on the left side of
According to an embodiment, which is not shown here, a respective elastic element can be held in the cutting holes 6, e.g. provided as a rubber piece, which is compressed in a spring elastic manner, when the cutting die 4 penetrates the respective cutting hole 6, and which expands again after the cutting die 4 has retracted from the cutting hole 6, which ejects the stamped blank 20 held in the cutting hole 6.
The apparatus described above is used for stamping stamped blanks 20 with a defined geometry and size, preferably made of leather, fibrous layups or foils, without loss or residual pieces, wherein the fibrous layups are preferably provided as layups, cloths, paper, nonwoven materials or felts, and are comprised of natural fibers, synthetic fibers, glass or carbon fibers, with and without binder, and the foil is comprised e.g. of plastic, metal or expanded graphite.
In a preferred manner, fibrous materials, preferably carbon fibers, are used for the flat materials 2, which are provided with additives and/or a curable binder. The flat material can be provided in the form of sheets with one layer or with plural layers.
In a particularly preferred manner, stamped blanks 20 with a thickness of 5 μm to 5 mm, and a width of 0.1 mm to 10 mm, and a length 1 mm to 100 mm can be produced by the apparatus.
In accordance with the provisions of the patent statutes, the principle and mode of operation of this invention have been explained and illustrated in its preferred embodiment. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.
This application is a continuation of International Application No. PCT/DE06/00811, filed May 11, 2006. The disclosure of this application is incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/DE06/00811 | 5/11/2006 | WO | 00 | 11/10/2008 |
