The present invention generally concerns a raising apparatus for being in a holding slot of a tool, for lifting punching parts or sheets of material, wherein the raising apparatus has a spring element.
When working on paper-based products e.g. paper, cardboard or cartons, raw sheets of material are typically used over tools like presses, punches or stripping tools. It is especially important when punching and stripping that parts punched or stripped from a curve sheet are reliably and quickly removed, since they will otherwise lead to problems with further processing stages. For example, cardboard elements punched out and not removed can lead to stoppages in the following processing machines. Besides that, it is important in the case of such applications that the sheets of material from which parts are punched or stripped are reliably transported further and do not become entangled in the tools. When removing entangled or jammed punching parts or sheets of material from machine tools, valuable time and work expenditure is wasted and unnecessary costs are incurred.
As an example of the state of the art, US 2008/0066595 A1 describes a bendable raising apparatus for lifting punching or stripping parts or sheets of material. The fact that simply a spring element with an unchanging spring rate is provided to lift the punching or stripping parts or sheets of material is, however, a problem in the raising apparatus described. Due to the single spring rate, it can happen that stripping or punching parts or sheets of material are lifted too quickly or too vigorously or too unreliably or too slowly, depending upon which materials or raw materials are being used.
It is a task of the present invention to rectify the disadvantages in the abovementioned state of the art, or at least to reduce them. It is in particular a task of the present invention to create a raising apparatus to lift punching parts or stripping parts or sheets of material which is adapted to lift punching or stripping parts or sheets of material from different raw materials reliably and quickly.
An aspect of the present invention is the provision of a raising apparatus for being in a holding slot of a tool, for lifting one or more punching parts and/or sheets of material, wherein the raising apparatus has first and second spring elements with different spring rates. Another aspect of the present invention is a method of using the raising apparatus.
In comparison with the state of the art, the invention has the advantage that, with the availability of a second spring element, a great degree of flexibility is achieved, whereby punching or stripping parts or sheets of material from different materials can be lifted quickly and reliably.
It is an intention of the present invention to have a raising apparatus to lift punching or stripping parts or sheets of material or materials, whereby the raising apparatus is usable in a holding slot of a tool, preferably a stripping tool or a punching tool. In doing so, the raising apparatus includes a first spring element with a first spring rate, as well as a second spring element with a different spring rate from the first spring element. The raising apparatus is particularly suitable for lifting cardboard punching parts, carton punching parts, paper punching parts, plastic punching parts or metal punching parts or stripping parts or sheets of material made of cardboard, carton, paper, plastic or metal.
A beneficial way to have the raising apparatus is with a stop block. This stop block is typically usable manually in the tool's holding slot. The stop block is typically cuboid or has at least one curve. The advantage of such a stop block lies in the fact that, with the help of this stop block, the raising apparatus is positioned precisely and held firmly in the holding slot.
A beneficial way to have the raising apparatus is with the spring rates of the first spring element being larger or smaller than the spring rates of the second spring element. The preferred mode for carrying out the invention is with the spring rate of the first spring element at 50% to 100%, preferably 60% to 400%, larger than the spring rate of the second spring element. It is preferable that in the invention the spring rate of the first spring element is 70% to 300% larger than the spring rates of the second spring element. With the particularly beneficial way to have the raising apparatus, the different spring rates of the first spring element and the second spring element result from the spring elements being different from one another in shape, size or material.
For typical modes of carrying out the invention, the raising apparatus includes at least a further spring element with a further spring rate, which differs from the spring rate of the other spring element or the spring rate of the second spring element. The beneficial way to have the invention is where a spring rate is at least not fixed in advance, but is freely applicable with the help of an adjusting device. The spring rate is set preferably continuously or in stages. The advantage of a raising apparatus with more than one spring element, wherein the different spring elements have different spring rates, lies in the fact that a greater flexibility is achieved with regard to processing different materials.
A beneficial way to have the invention is to have the raising apparatus made from metal or plastic. Typical raising apparatuses are made from metal and plastic according to the invention.
A beneficial way to have the invention is to have the first spring element or the second spring element of the raising apparatus in each case include a label to easily differentiate between the two spring elements. It is advantageous to have labelling on at least one spring element to easily differentiate a geometric form or to have a coloured label on at least one spring element. Such labelling offers the advantage that a user, when using the raising apparatus, can quickly and easily recognise which operating position shall be used, so which spring element is on top, when applying the raising apparatus in the stripping tool, and which spring rate takes effect on the workpiece or the punching parts or the stripping parts.
A beneficial way to have the invention is to have the raising apparatus include at least one shape in the place where the spring elements meet the stop block. This shape typically leads to improved mechanical stability of the connection between the stop block and the spring elements. An advantage of such a shape lies in the fact that breaking off or bending the raising apparatus in the area where the stop block and spring elements meet is prevented.
A beneficial way to have the invention is to have the thickness of a raising apparatus stop block greater than the width of a holding slot of the stripping tool. A width of the first spring element and a width of the second spring element is typically smaller than the width of the holding slot, so that the first spring element and the second spring element are extendable in the holding slot. The holding slot typically includes a holding socket, wherein the thickness of the stop block is smaller than the width of the holding socket, so that the stop block can be inserted in the holding socket. Due to the fact that the stop block cannot be inserted in each position in the holding slot, but simply in the holding socket of the holding slot, it is guaranteed that the raising apparatus is positioned correctly in the holding slot.
A beneficial way to have the invention is to have the stop block contain at least one curve. Particularly good modes of the invention include there being several curves or curved edges of the cuboid stop block, or rounded features of the cuboid stop block. The benefit of such a curve or curving is simplified insertion of the stop block in the holding socket.
When the raising apparatus is used according to the invention, the raising apparatus shall initially be used with the first spring element or initially with the second spring element in the holding slot of the stripping tool, the spring element initially in use sticks out at least partly from the holding slot of the raising apparatus in a still position. If a workpiece, work material or sheet of material is positioned over the raising apparatus and is then punched or stripped, the workpiece, work material or the sheet of material shall be squeezed by a pressure element, whereby also the spring element sticking out from the tool is squeezed from the still position into a punching position. Finally, a punch shall be made from the work material using typical shapes. As soon as the spring rate of the spring element sticking out is sufficient to lift the punching part or stripping part or sheet of material, work material or workpiece punched out, the raising apparatus turns from the punching position back to the still position, whereby the punching or stripping part, or sheet of material, work material or workpiece is lifted.
In the following the invention is explained in more detail using schematic illustrations, which show:
The invention is not limited to the examples presented above. Rather, the scope of protection is defined by the claims presented below.
Number | Date | Country | Kind |
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102010036476.2 | Jul 2010 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2011/003575 | 7/18/2011 | WO | 00 | 1/17/2013 |