EP3488968B1 - Device for fixing a sanding shoe - Google Patents

Description

The invention relates to a sanding shoe holder according to claim 1.

State of the art

Sanding shoes and sanding shoe carriers or sanding shoe mounts are known from the prior art. However, these differ in essential features from the present invention.

In this context, the EP 2 189 243 A2 which forms the basis of the preamble of claim 1. There, a sanding pad is disclosed which, in various designs, can be positively introduced into a sanding pad receptacle and has different shapes for this purpose.

In the WO 2006/012843 A1 discloses a sanding shoe in which the receiving or carrier rail is made of metal. The same applies to the one in the DE 203 15 291 U1 shown grinding shoe. In this context, however, the use of metal brings several disadvantages, such as high

Thermal expansion, inflexibility and other properties that negatively affect the grinding process.

Furthermore, grinding shoes are known in which compressed air is used, such as in the DE 10 2005 054 213 A1 are revealed. There, so-called material strips are blown up using compressed air so that the contact pressure on a sanding belt can be controlled. However, an intermediate material that takes on a damping function is missing here.

the DE 4114819 C1 shows a system in which a tubular and inflatable pressure bag is used. This has a similar function as the material strips from the above DE 10 2005 054 213 A1 and is also filled with compressed air. Again, the support plate is made of sheet metal or another metal. In addition, replacing the pressure element or the sanding pad is expensive.

Disclosure of Invention task

The object of the present invention is to overcome the disadvantages of the prior art. In particular, a sanding shoe mount is to be provided that overcomes the disadvantages of previously known sanding shoe mounts. In this context, the saving of material and the associated costs should also be defined as a task.

solution of the task

The features of claim 1 lead to the solution of the problem.

A part of the invention is a sanding pad for a belt sander. This sanding pad consists of, among other things, a carrier. It can also consist of an intermediate material and a grinding belt activator.

The first layer of the sanding pad forms a backing.

This carrier advantageously consists of a flexible material such as textile fabric, hard paper, paper, cardboard, soft plastic film made of PU foam or PES or a mixture of these materials. This allows the carrier to be flexible, which has several advantages compared to conventional carriers or plates made of metal or hard plastic.

A major advantage of this carrier is that there is a low material thickness tolerance, which is of great importance for the grinding process in order to be able to achieve the lowest possible thickness tolerances of the ground plate.

Furthermore, the carrier of the sanding pad has only a very low thermal expansion, which leads to further advantages in the grinding process, especially compared to carriers made of plastic or metal.

Another advantage of the sanding pad with the carrier made of a flexible material such as textile fabric, hard paper, paper, cardboard, soft plastic film made of PU foam or PES or a mixture of these materials is that, compared to conventional sanding pads, after the use can be easily and easily disposed of in an incineration process.

Furthermore, the shape in connection with a sanding pad receptacle leads to a further advantage, which is expressed in the way that the sanding pad can be changed or exchanged more quickly and easily.

The second layer of the sliding shoe, the intermediate material, can have different thicknesses and/or different degrees of hardness and, depending on the requirements, consist of different plastics or plastic compounds, such as PES, PU foam, fleece or latex fleece. This achieves an excellent padding and cushioning function. By varying the intermediate material, it is possible to provide grinding shoes for a wide variety of and sometimes very special belt grinding processes. It is also possible to give the intermediate material certain shapes through the application process or through a removal process and to adapt it to individual requirements in the belt grinding process.

The intermediate material can be glued to the flexible carrier over the entire surface or only partially. Depending on the requirements of the machine, the specialist can make a selection of intermediate materials that are bonded over the entire surface or only partially.

If, for example, the intermediate material is not glued or glued to the carrier at the longitudinal edges, there is the advantage that material stresses when the sanding pad is pushed in are reduced and the entire process of pushing in the sanding pad is thus facilitated. For example, the intermediate material can be in a range of 3-10 mm, preferably 5 mm, on the longitudinal edges of the sanding shoe and can be glued. In detail, this means that, for example, a carrier which has a width of 70 mm is glued in the middle over about 60 mm and is not glued on the longitudinal walls over 5 mm. In other cases, however, provision can also be made for the carrier to be extended over its entire width of 70 mm can be glued. In other exemplary embodiments, it is conceivable that the intermediate material is glued to the carrier only at certain points.

The third layer of the sliding shoe is formed by the abrasive belt activator, the basic component of which is graphite. As a rule, this upper layer is less thick than the intermediate material. The grinding belt activator advantageously forms a sliding layer and therefore fulfills a sliding function for the grinding belt.

A new grinding shoe carrier according to the invention, hereinafter referred to as a grinding shoe holder, is also available for receiving the grinding shoe.

As the name already describes, this grinding shoe holder according to the invention accommodates the grinding shoe and fixes it in a simple and advantageous manner.

The sanding shoe mount is connected to a carrier mount rail of the belt grinder via a mount.

In one exemplary embodiment, the grinding shoe mount according to the invention has chamfers on both sides of the contact surface, which, depending on the application and grinding belt, can occupy an area of 1/8 to 1/4 of the contact surface. A rounding off or a flattening can also be considered here as a chamfer.

These chamfers cause the contact surface to be angled rather than flat. The main advantage of this is that the chamfers or the angled shape of the contact surface are transferred to the flexible sanding shoe. By transferring the angled shape of the contact surface given by the chamfers, the edges of the abrasive belt indicator are forced to be flattened. The flattening of those edges is from This is of particular importance, since the sanding shoe and then the sanding belt are often damaged if the edge is not flattened.

In order to achieve a flattening of the edges of the intermediate material or of the grinding belt activator, very complex and expensive additional processing steps were previously necessary. For example, the edges of the intermediate material were sanded before the layer with the sanding belt activator was applied, to create an angled shape with flattened edges.

This time-consuming processing of the edges of the sanding pad is no longer necessary thanks to the combination of the sanding pad with the flexible carrier made from, for example, textile fabric, laminated paper, paper, cardboard, soft plastic film made from PU foam or PES textile fabric, or a mixture of these materials and the abrasive belt holder according to the invention the locking chambers and the angled contact surface.

Furthermore, the present invention simplifies the production of grinding shoes and saves time and money by eliminating previously necessary work steps, for example grinding the edges of the intermediate material. This applies above all to the substitution of expensive metal with, for example, cheaper textile fabric or, for example, laminated paper. In this context, it has been found that ABS (acrylonitrile butadiene styrene) and wood can also be considered as materials for the carrier. Finally, it is important that the carrier material has sufficient flexibility to accommodate the functional characteristics described herein.

1. 1. Der Schleifschuh wird in die Schleifschuhaufnahme eingeschoben.
2. 2. Durch das Spannen des Schleifbandes wird der Schleifschuh auf die Kontaktfläche der Schleifschuhaufnahme gepresst. Somit ist der Schleifschuh gleichmäßig in der Schleifschuhaufnahme über die Kontaktfläche gespannt.
3. 3. Mit Hilfe von beispielsweise Druckluft wird ein Expansionselement expandiert und somit der Schleifschuh in der Schleifschuhaufnahme fixiert.
4. 4. Bei einem Schleifschuhwechsel wird das Expansionselement durch Ablassen des Expansionsmediums, beispielsweise Druckluft, entspannt und der Schleifschuh kann herausgezogen werden.

In addition, the sanding pad can be easily replaced by replacing the previously used metal or hard plastic such as ABS with, for example, hard paper for the wearer of the sanding pad be disposed of cheaply through an incineration process. There is no need for time-consuming disposal or recycling.

1. 1. The sanding pad is pushed into the sanding pad holder.
2. 2. By tensioning the sanding belt, the sanding pad is pressed onto the contact surface of the sanding pad holder. Thus, the sanding pad is evenly clamped in the sanding pad mount across the contact surface.
3. 3. With the help of compressed air, for example, an expansion element is expanded and the sanding pad is thus fixed in the sanding pad mount.
4. 4. When changing the sanding pad, the expansion element is relieved by releasing the expansion medium, for example compressed air, and the sanding pad can be pulled out.

In another exemplary embodiment, a flat pressure sensor is installed on the support surface or contact surface, preferably over a width of 55 mm and the respective plate length of the sanding pad carrier, and is connected to machine software.

The elastic insert then sits exactly on this bearing surface or contact surface and if there is a load, as is the case during grinding, the pressure generated and the exact distribution of the pressure over the bearing surface or contact surface are displayed in the software. Such a surface sensor can only be used with an elastic carrier. In the case of a rigid support, the pressure would not show up at specific points, but would be distributed over the entire rigid support.

In the embodiment shown here, on the other hand, the middle layer (PES, foam...) lies directly on the surface sensor. A significant advantage would be given by the fact that with an uneven distribution of pressure on the inserts, as is the case, for example, when the upper and lower insert in the If the machines are not parallel to each other or the insert is crooked, the pressure distribution over the entire contact surface or contact surface would be shown on a display and the machine operator would know immediately when he had to set up the inserts again or correct their position. Until now, the setting can only be checked using a complex process, such as using a bearing ring, ruler or the like.

character description

• Figur 1 eine geschnittene Darstellung einer Schleifschuhaufnahme 5 mit einem Schleifschuh 1,
• Figur 2 eine geschnittene Darstellung einer Schleifschuhaufnahme 5.1 einem Schleifschuh 1.1.

Further advantages, features and details of the invention result from the following description of preferred exemplary embodiments and from the drawings; these show in:

• figure 1 a sectional view of a sanding shoe mount 5 with a sanding shoe 1,
• figure 2 a sectional view of a sanding shoe mount 5.1 a sanding shoe 1.1.

In figure 1 a sectional representation of an exemplary embodiment according to the invention of a sanding pad holder 5 with an inserted sanding pad 1 can be seen.

The grinding shoe 1 consists of three layers. An intermediate material 3 is arranged in the middle. On the one hand the intermediate material 3 is the carrier 2 consisting of hard paper. On the other hand the intermediate material 3 has a further layer applied which is referred to as the grinding belt activator 4 . The intermediate material 3 and the grinding belt activator 4 do not completely cover the carrier 2, so that a first carrier strip 16 and a second carrier strip 16.1 of the carrier 2 remain free.

The sanding shoe mount 5 has a contact surface 9 on the side O, on which the sanding shoe 1 rests. A first chamfer 10 on the one hand and a second chamfer 10.1 on the other hand are arranged on the contact surface 9 . This gives the contact surface 9 an angled shape. This angled shape of the contact surface 9 is transferred to the resting sanding pad 1, since this has a flexible carrier. As a result of this effect, the outer edges of the intermediate material 3 and of the abrasive belt indicator 4 bend slightly downwards in the direction of a side U.

The first bevel 10 and the second bevel 10.1 mark the respective transition to the fixing chambers 7 and 7.1 arranged on both sides and in mirror image. The two carrier strips 16 and 16.1 of the carrier 2 of the grinding shoe 1 are pushed into the fixing chambers 7 and 7.1 of the grinding shoe holder 5 via a slit-shaped opening 17 or 17.1.

Trapezoidal expansion elements 6 and 6.1 are arranged within the fixing chambers 7 and 7.1. The expansion elements 6 and 6.1 each have an expansion core 12 and 12.1.

An expansion chamber 8 or 8.1 is arranged between an inner wall 13 or 13.1 and the expansion element 6 or 6.1.

The first carrier strip 16 and the second carrier strip 16.1 of the carrier 2 are pushed into the fixing chamber 7 or 7.1 via the slot-shaped opening 17 or 17.1 in such a way that they are located between the inner wall 13 or 13.1 and the expansion space 8 or 8.1.

The grinding shoe mount 5 has a mount 14 on the side U. The mount 14 is T-shaped, with an additional groove-shaped recess 15 being present.

This in figure 2 illustrated embodiment not according to the invention shows a grinding shoe 1.1 and a grinding shoe mount 5.1.

In this exemplary embodiment, a contact surface 9.1 of the grinding shoe mount 5.1 is formed straight and does not have chamfers. The contact surface 9.1 merges directly into the slot-shaped opening 17 or 17.1 on both sides to the fixing chambers 7 and 7.1.

Due to the continuously flat shape of the contact surface 9.1, the contact pad 1.1 will not bend in the U direction. So that an angled shape of the grinding shoe 1.1 resting on the grinding shoe mount 5.1 is achieved, the intermediate material 3 has ground edges 11, 11.1. <b>Reference List</b> 1, 1.1 grinding shoe u side 2 carrier O side 3 between materials 36 4 sanding belt indicator 37 5, 5.1 sanding shoe mount 38 6, 6.1 expansion element 39 7, 7.1 retention chamber 40 8, 8.1 expansion space 41 9, 9.1 contact surface 42 10, 10.1 chamfer 43 11, 11.1 edge 44 12, 12.1 expansion core 45 13, 13.1 inner wall 46 14 Recording 47 15 recess 48 16, 16.1 carrier strips 49 17, 17.1 opening 50 18 51 19 52 20 53 21 54 22 55 23 56 24 57 25 58 26 59 27 60 28 61 29 62 30 63 31 64 32 65 33 66

Claims (2)

1. Sanding shoe holder (5, 5.1) for a sanding shoe (1, 1.1) with an elastic carrier (2), wherein a contact surface (9, 9.1) is provided for abutment of the carrier (2), wherein the contact surface (9) has a chamfer (10, 10.1),
   characterised in that
   the contact surface (9) has a surface sensor.
2. Sanding shoe holder according to claim 1, characterised in that the chamfer (10, 10.1) comprises 1/4 or 1/5 or 1/6 or 1/7 or 1/8 of the contact surface in each case.

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