DE20022441U1 - Device for supporting workpieces - Google Patents

Description

Friz Maschinenbau GmbH

In Holderbusch 7

D-74189 Weinsberg

DEVICE FOR SUPPORTING AND FIXING ITEMS TO BE LAMINATED

WORKPIECES

Field of the invention

The invention relates to a device for supporting and fixing workpieces to be laminated on press tables.

Workpieces are laminated with various surface materials, such as wood veneers and plastic films, in presses. Presses with and without membranes can be used. Such a press system includes press tables on which the workpieces to be laminated are arranged and fixed. These press tables can usually be moved from an easily accessible loading position outside the actual press room into the press and vice versa.

Devices for supporting the workpieces are provided on the press tables, either integrated into them or attachable. These devices are used to hold the workpieces in place during lamination. They also help to prevent the film from indenting too much in the area of the underside of the workpiece. This largely prevents film breakage, which leads to rejects.

State of the art

Various systems are known in technology for such a device for supporting workpieces.

In one of these systems, which is not documented in print, the press tables, which are generally referred to as loading tables, are equipped with support elements at the points where the workpieces are arranged for processing. These support elements are usually in the form of plate-shaped supports, the outlines of which correspond to the contour of the workpiece to be processed, but are set back by a few millimeters, i.e. are smaller. This means that the edges of the workpieces protrude a few millimeters beyond the plate-shaped support. The plate-shaped supports are individually adapted for each workpiece contour. This means in particular that if the contours of the workpieces are more detailed, these must also be reflected in the supports. This means that appropriate supports must be provided for each workpiece shape to be processed, which may have to be manufactured separately in the case of complicated contours or special applications.

Alternatively, systems are known that work with pin- or stamp-like support elements that are mounted in the press table or a corresponding support structure of the press table so that they can be extended and lowered. EP 0 505 668 Bl describes a work table with vacuum suction of the support elements for machine tools. The workpiece table contains a large number of suction heads, several of which are extended via an actuator depending on the workpiece contour. The suction cups can be arranged in groups with different pitches, which means that different workpiece formats and sizes can be supported.

Another support device is described in DE 297 19 589. It provides a number of supports that are mounted vertically in openings in a table top. The

workpiece. Again, an appropriate number of supports can be extended to reproduce the workpiece contour and to support the workpiece well. The base under the supports is designed as a conveyor belt.

DE 195 00 400 describes another corresponding device. A plug-in plate on the table has a large number of plug-in and receiving holes. Support plugs can be inserted into the plug-in holes and, when not needed, stored in the receiving holes. Depending on the arrangement of the plug-in holes, the plugs can be used to support different contours of a workpiece.

In order to prevent a coating film from tearing, which has only limited stretchability when heated, it is necessary to prevent the film from indenting too much on the underside of the workpieces lying on support elements on the workpiece table. This is particularly critical because the film itself is often directly impacted by an air cushion. Therefore, according to DE 198 26 494 Cl, a method is proposed in which, beneath each workpiece, through the workpiece table, with the coating film lying on the workpiece table, supporting air is pressed into the space defined by the underside of the workpiece, the film and the top of the table in such a way that the film is prevented from arching in this space until it reaches the tear limit.

Description of the invention

The invention is based on the object of creating a device for supporting and fixing workpieces, which is suitable for supporting workpieces of various geometries without causing a strong indentation of a

coating material during laminating on presses.

This object is achieved by a device for supporting workpieces having the features of claim 1.

The invention is based on the idea of using a system in which the support and fixing is created from one or more support elements. The support elements have geometries from which geometries can in turn be assembled according to the contours of the workpiece. These support elements must be freely movable and fastened on the press table. For this purpose, the press table or an insert or support of the press table has a corresponding adhesive device that forms an immovable connection with an adhesive piece provided on the support element during the pressing process. The support elements can thus be positioned and fixed in any position on the table. The free positioning of the support elements, without being tied to holes or predetermined locations of supports in the press table, means that almost any workpiece geometry can be supported by the support elements. This only depends on the geometries of the support elements. The outer contour of the support elements can thus be individually adapted to that of the workpiece without a special support having to be manufactured or provided for each workpiece. Rather, with some standard support elements, any geometries can be created that adapt to the workpiece contours in such a way that indentation of a coating as a surface material is prevented during the pressing process.

Advantageous embodiments are characterized by the remaining claims.

According to a preferred embodiment, the top or insert is integrated into the press table. This enables a compact design of the press table without the need for additional securing devices for the top or insert.

The support elements advantageously have round, square or irregular contours. By providing a large number of different support elements, whereby different cuboid, square or circular shapes as well as irregular geometries can be realized, it is possible to adapt the support base to the workpiece contour without any problems. In particular, the geometries of the increasingly detailed contours can be reproduced by this large number of different support elements. Of course, the support elements can be aligned differently on the press table, so that a support element with a semicircular contour, for example, can be used with both the straight side and the round side facing outwards to reproduce the contour of the workpiece.

Advantageously, the support elements used have the same height. This means that any combination of support elements is possible without having to pay attention to their height. However, different heights can alternatively be used to support workpieces with a non-flat underside.

According to an advantageous embodiment, the support elements are attached to the top or insert for the press table with a suction button device that interacts with a corresponding smooth surface. The suction buttons can be provided on both the side of the press table and on the side of the support elements. Accordingly, the smooth surface is attached to the other of the two elements. A suction connection

enables quick, reliable fastening of the support elements to the top or insert for the press table.

Alternatively, the adhesive connection between the support elements and the top or insert of the press table can be advantageously implemented using Velcro elements. In this case, either the support element has a Velcro element with loops and the top or insert for the press table has a counterpart with hooks or pins, so that a normal Velcro connection can be made. The arrangement of the loop piece and the hook or pin piece can also be different, so that the top or insert for the press table is formed by the loop piece. This option also ensures a reliable, secure connection.

According to a further preferred embodiment, the adhesive connection between the support elements and the overlay or insert for the press table is made using magnets and steel elements. Again, the magnet itself can be mounted both in the support elements and in the overlay or insert. If the magnet is provided in the support elements, it is advantageously placed near the end of the support elements facing the press table. Accordingly, the overlay or insert, or in the second case the support element, has a steel element that creates an adhesive connection with the magnet.

Another advantageous alternative for creating the adhesive connection is to provide a smooth surface on the one hand and an anti-slip mat on the other. Again, it is irrelevant whether the anti-slip mat is attached to the support element or the support or insert for the "press table". The other element should be designed as a smooth surface accordingly. Both the alternative of the magnetic connection and the route via a

Anti-slip mats ensure that the support elements are attached quickly, precisely and securely.

According to a preferred embodiment, the counter device in or on the top or insert for the press table is designed in the form of a mat or plate and extends essentially over the entire press table. For structural reasons, it may alternatively be advantageous to put together several strip-shaped or plate-shaped elements and thereby form the counter device. By having a mat or plate-shaped counter device that extends essentially over the entire press table, it is possible to use the entire surface of the press table to position the support elements. This makes it easier to use the entire press table to position several workpieces that can be laminated at the same time. This enables economical, rapid and therefore cost-effective production.

According to a preferred embodiment, the counter device, particularly if it is in mat or plate form, has markings that facilitate the positioning of the support elements. This enables rapid orientation on the press table, which in turn shortens the positioning time for the support elements and thus speeds up the entire manufacturing process.

According to a preferred embodiment, the support element or elements are designed to taper upwards. This can be the case over the entire circumference or only over parts of it. This conical design prevents the film used to cover the workpiece from sticking to the support element, which in turn supports an economical manufacturing process. On the other hand, the connection surfaces to other support elements are preferably

not conical, so that the support elements fit together well without any gaps.

According to a preferred embodiment, the device further comprises an automatic positioning device for positioning the support element(s). This means that during a loading process of the press table, the support elements are automatically placed on the table. This in turn allows, with suitable control, the surface of the press table to be used optimally in order to laminate as many workpieces as possible at the same time.

According to a preferred embodiment, an optical verification device is also provided which, after positioning the support element(s), compares the position of the support elements with a predetermined pattern. Incorrect positioning of the support elements can thus be virtually ruled out.

Preferably, the support elements are provided with a material on their side surfaces that counteracts the adhesion of the laminating film. This also prevents indentations up to the support element. This in turn serves to largely rule out tearing of the laminating film or laminating material.

Preferably, the support elements have a device on the side facing the workpiece for non-slip fastening of the workpiece to the support elements. This anti-slip device can in turn be implemented using suction cups, anti-slip films or similar. This prevents the position of the workpiece on the support elements from shifting and, in some areas, an excessively large protruding edge of the workpiece over the support element, which would lead to indentation and thus tearing of the laminating material.

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Short description of the drawings

The invention is described below purely by way of example with reference to
attached figures, in which:

Fig. 1 is a sectional view through an inventive
Device with workpiece and laminating material placed on it
is;

Fig. 2 shows a side view of a support element in a first embodiment;

Fig. 3 shows a plan view of a support element;

Fig. 4 shows a plan view of another support element;

Fig. 5 shows a side view of another support element;

Fig. 6 shows a plan view of the support element of Fig. 5;

Fig. 7 shows a side view of a support element with a circumferential conical taper;

Fig. 8 shows a plan view of a support element with a conical taper;

Fig. 9 shows a plan view of another embodiment of a support element with conical support;

Fig. 10 is a sectional view of a support element with
Velcro device as adhesive element;

Fig. 11 a sectional view of a support element with magnet
as a detention facility;

Fig. 12 shows a press table insert or support designed as a steel plate with perforation;

Fig. 13 shows an insert or support of a press table, which is designed as a Velcro element; and

Fig. 14 shows an arrangement of various support elements in plan view for supporting a workpiece.

Ways to implement the invention

Figure 1 shows a device for supporting workpieces 10 according to the present invention. A laminating film 12 is already laminated over a workpiece 14. Instead of a laminating film 12, a veneer or the like can of course also be used.

As can be seen from Figure 1, the workpiece 14 rests on a support element 20. The support element 20 in turn lies on a support or insert 30 of a press table (not shown). The support or insert 30 is provided with channels 32 which serve to suck out air and thus suck in a laminating film 12 or another laminating material. The support or insert 30 for the press table is thus designed to be porous.

Figure 2 shows a side view of a cylindrical support element 20. Figures 3 and 4 show possible top views of the same support element 20. As can be seen, the support element 20 can have round, rectangular or square contours in the top view. Other embodiments, such as oval, irregular or polygonal contours, are also conceivable.

An alternative to the embodiments of the support element 20 shown in Figures 2 to 4 is shown in Figure 5 in side view and Figure 6 in plan view. The support element 20 also has a cylindrical shape

, with the upper contour being formed by a hexagon, which can also be irregularly shaped.

Figures 7 to 9 show further support elements 20. In contrast to the support elements shown in Figures 2 to 6, these are not cylindrical but frustoconical. They therefore taper towards the top. In the case shown, the taper runs all the way around the support element. In the top view, as shown in Figures 8 and 9, round, rectangular or square shapes are also possible. Alternative shapes not shown, such as a completely free shape, oval shapes or similar, are also conceivable. The frustoconical shape helps to keep the space between the workpiece 14, the support element 20, the press table 30 and the laminating film 12 as small as possible before laminating, so that excessive stretching of the laminating film is prevented. This reduces the risk of cracking of the laminating film or other laminating material.

Figures 10 and 11 show a truncated cone-shaped support element 20 in a sectional view. In Figure 10, the underside of the truncated cone-shaped support element 20 is provided with an adhesion device 22 in the form of a Velcro strip. When the support element 20 is placed on a corresponding top or insert of the press table, as shown in Figure 13, the Velcro strip 22 can interact with this.

Figure 11 shows an alternative embodiment of the conical support element 20. In the case shown in Figure 11, the adhesion device 24 in the form of a magnet is inserted into the lower region of the conical support element 20. In this case, the plate-shaped support and insert of the press table is a steel plate with through holes, as shown in Figure 12.

The pads or inserts for the press table (not shown) shown in Figures 12 and 13 are porous. In Figure 13, this is achieved by channels 32 in the form of through holes in the steel plate. In the case of a Velcro mat from Figure 13, fine passages are usually already present in the Velcro mat without any additional precautions.

The supports or inserts 30 for the press table shown in Figures 12 and 13 preferably extend over the entire surface of the press table. This allows the entire surface of the press table to be utilized for arranging support elements 20.

Figure 14 shows an arrangement of several support elements 2 0. As can be seen from the top view shown in Figure 14, a cuboid-shaped contour with a rounded corner is created by, for example, five support elements 2 0. The contour is arranged in such a way that the outer contours of the support elements correspond to the contour of the workpiece 14, whereby the workpiece 14, as can best be seen in Figure 1, projects slightly beyond the contour edge formed by the support elements. It can also be seen that not the entire workpiece but primarily its edge must be supported.

The arrangement of the support elements on the press table and the subsequent laminating process are briefly described below.

First, a certain number of support elements are selected that can reproduce the contour of a workpiece as well as possible. This can be done, for example, with the help of electronic data processing. Differently shaped support elements can be selected simultaneously in order to reproduce the workpiece contour, as shown, for example, in Figure

14. In the configuration shown in Figure 14, five support elements are used to form a rectangular contour with a rounded corner. In particular, these are four rectangular support elements and one support element which is quarter-circular in plan view. These support elements are then arranged and fixed on the press table via the adhesion device 22, 24 on a support or insert which is essentially flat. In the example shown in Figure 14, if the underside of a workpiece 14 is an essentially flat surface, the support elements 20 are preferably all the same height so that the workpiece 14 rests flat on the support elements. If a workpiece 14 is selected which has a stepped underside, support elements 20 of different heights can also be used.

The arrangement of the support elements 2 0 on the top or insert of the press table 30 can be carried out using an automatic positioning device which selects an optimal arrangement of the support elements using a suitable programmable control so that as much of the surface of the press table as possible is used for laminating. Alternatively, the arrangement of the support elements 20 can also be carried out manually. In this case, it is advantageous if markings are provided on the mat- or plate-shaped top or insert of the press table to make it easier to arrange the support elements. After the support elements have been arranged on the top or insert 30, an optical verification device can be used to check the position of the support elements and, if necessary, to determine any deviations from a previously determined optimal arrangement. These are then corrected. The workpieces 14 are then placed on the support elements 20. The workpieces 14 are placed in such a way that they protrude slightly beyond the support elements 2 0 at the outer edges of the support elements 2 0. This allows a laminating film

12 are placed around the workpiece 14 and are also attached to its underside.

The press table, which is usually designed to be movable, is then pushed into the actual press. The press is closed and the surface material is placed relatively loosely over the workpieces 14 placed on the support elements 20 and the press table. The press is then closed and, for example in the case of a membrane press, the film is preheated using the membrane if necessary. The actual pressing process then takes place. With and/or without a membrane, a negative pressure is generated between the surface material and the press table using the porous openings in the press table and/or the openings in its top or insert by sucking out the air between the press table and the surface material. The resulting negative pressure attracts the laminating film or veneer to the workpiece and the top or insert. Because only a relatively small protruding edge is provided between the workpiece and the support element, which is small all the way around the circumference, bulging inwards of the laminating film 12 during the pressing process is largely prevented. This bulging can otherwise lead to tearing of the laminating film 12 or the veneer. This means a defective workpiece and therefore rejects.

The essential aspect of the invention is that support elements can be moved freely on a support or insert of the press table and can be fixed in any position on the press table or its support by means of an adhesive connection, which is created by an adhesive element on the support elements and on the press table. This eliminates the need to specifically produce certain supports for certain workpieces and, on the other hand, there is no risk of the laminating film tearing due to high indentations during the pressing process.

Claims (15)

1. Device ( 10 ) for supporting and fixing workpieces ( 14 ) to be laminated on tables of presses for laminating the workpieces ( 14 ), comprising: - a porous, flat top or insert ( 30 ) for the press table; and - at least one support element ( 20 ) which is freely displaceable on the support or insert ( 30 ) and provided with a support surface for the workpiece; wherein the support element ( 20 ) comprises an adhesion device ( 22 , 24 ) which forms an adhesive connection with a corresponding counter-device in or on the support ( 30 ) for the press table. 2. Device ( 10 ) according to claim 1, characterized in that the overlay or insert ( 30 ) is integrated into the press table. 3. Device ( 10 ) according to one of the preceding claims, characterized in that the at least one support element ( 20 ) has a round, angular or irregular contour. 4. Device ( 10 ) according to one of the preceding claims, characterized in that several support elements ( 20 ) are provided which have the same height. 5. Device ( 10 ) according to one of the preceding claims, characterized in that either the adhesion device ( 22 , 24 ) or the counter device comprises at least one suction cup and the other of the devices comprises a smooth surface. 6. Device ( 10 ) according to one of claims 1 to 4, characterized in that the adhesion device ( 22 ) and the counter device are each Velcro elements which adhere to one another. 7. Device ( 10 ) according to one of claims 1 to 4, characterized in that either the adhesion ( 24 ) or the counter device comprises a magnet and the other of the devices comprises a steel element. 8. Device ( 10 ) according to one of claims 1 to 4, characterized in that either the adhesion or the counter device is a smooth surface and the other of the devices comprises an anti-slip mat. 9. Device ( 10 ) according to one of the preceding claims, characterized in that the counter device is mat- or plate-shaped and extends substantially over the entire press table. 10. Device ( 10 ) according to claim 9, characterized in that markings are applied to the mat or plate which facilitate the positioning of the support elements ( 20 ). 11. Device ( 10 ) according to one of the preceding claims, characterized in that the at least one support element ( 20 ) is designed to taper upwards. 12. Device ( 10 ) according to one of the preceding claims, further comprising an automatic positioning device for positioning the at least one support element ( 20 ). 13. Device ( 10 ) according to claim 12, further comprising an optical verification device which, after positioning the at least one support element ( 20 ), compares the position of the support elements with a predetermined pattern. 14. Device ( 10 ) according to one of the preceding claims, characterized in that the at least one support element ( 20 ) is provided on its lateral surfaces with a material which counteracts the adhesion of a laminating film ( 12 ). 15. Device ( 10 ) according to one of the preceding claims, characterized in that the at least one support element ( 20 ) is provided on its side facing the workpiece with a device for non-slip fastening of the workpiece ( 14 ).