EP3178606B1 - Sanding shoe and a method for fixing the sanding shoe - Google Patents

Description

The invention relates to a sanding shoe according to the preamble of claim 1 and a method according to claim 2.

State of the art

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

It is first on the GB 1,142,908 A pointed. There is disclosed a sanding pad, which is spring-loaded and thus reacts flexibly to impacts.

Next will be on the US 5,575,972 A1 which also discloses a spring construction in a grinding machine.

Also on the DE 843012 C1 referenced, which discloses a grinding and pressure shoe on belt grinding machines, wherein a directly resilient connection is shown in the form of a band steel spring.

In addition, on the DE 33 28 398 A1 pointed. There is a so-called pressure bar for belt grinding machines, in which an air cushion is provided above the sanding pad.

In the WO 2006/012843 A1 , which forms the basis for the preamble of claim 1, a sanding pad is disclosed in which the receiving or support rail is made of metal. The same applies to the in the DE 20315291 U1 shown grinding shoe. In this context, however, the use of metal involves several disadvantages, such as high thermal expansion, inflexibility and other properties that adversely affect the grinding process.

Furthermore, sanding shoes are known in which compressed air is used, such as those in the DE 10 2005 054 213 A1 are disclosed. There, so-called material strips are inflated by means of compressed air, so that the contact pressure can be controlled on a grinding belt. An intermediate material, which assumes damping function, is missing here however.

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

Disclosure of the invention task

The object of the present invention is to overcome the disadvantages of the prior art. In particular, a method is to be provided which overcomes the disadvantages of previously known sanding shoes and abrasive shoe carrier. In this context, the saving of material and associated costs should be defined as a task.

Solution of the task

To achieve the object, the features according to claims 1 and 2.

A part of the invention is an abrasive shoe according to the invention for a belt grinding machine. This sanding shoe consists of three layers: a carrier, an intermediate material and a sliding layer.

The first layer of the abrasive shoe according to the invention forms a carrier. This support is advantageously made of a flexible material such as textile fabric, kraft paper, paper, cardboard, soft plastic film of PU foam or a mixture of these materials. This allows the carrier to be flexible, which has several advantages over conventional metal or hard plastic carriers.

A significant advantage of this inventive carrier is that a low material thickness tolerance is given, which is of great importance for the grinding process in order to achieve the smallest possible thickness tolerances of the ground plate.

Furthermore, the carrier according to the invention of the sanding pad has only a very low thermal expansion, this leads in particular compared to plastic or metal supports to further advantages in the grinding process.

Another advantage of the inventive sanding pad with the support of a flexible material such as textile fabric, paper, cardboard, soft plastic film made of PU foam or a mixture of these materials is that this, compared to the conventional Sanding shoes that can be disposed of easily and easily in a combustion process after use.

Furthermore, the shaping according to the invention in conjunction with a sanding shoe receptacle according to the invention leads to a further advantage, which manifests itself in the sense that a quick and uncomplicated replacement or replacement of the sanding pad is possible.

The second layer of the sliding shoe according to the invention, the intermediate material, may have different thicknesses and / or different degrees of hardness and, depending on requirements, consist of different plastics or plastic compounds, such as a PU foam, nonwoven or latex nonwoven. This achieves an excellent padding and damping function. The variation of the intermediate material makes it possible to provide sanding shoes for a wide variety of very special belt sanding processes. It is also possible to give the intermediate material certain formations by the application process or by a removal process and adapt to individual requirements in the belt grinding process.

The intermediate material can be glued over the entire surface or only partially to the flexible support. Depending on the requirements of the machine, the skilled person can make a selection of intermediate or only partially bonded intermediate materials for this purpose.

If, for example, the intermediate material at the longitudinal edges is not glued or glued to the carrier, there is the advantage that material tensions during insertion of the grinding shoe are reduced and thus the entire insertion process of the grinding shoe is facilitated. Thus, the intermediate material, for example, in a range of 3-10 mm, preferably 5 mm at the longitudinal edges of the sanding pad and glued executed. This means in more detail that, for example, a carrier, which has a width of 70 mm is glued to the center of about 60 mm and is not glued to the longitudinal walls to 5 mm. In other cases, however, it can also be provided that the carrier can be glued over its entire width of 70 mm. In other embodiments, in turn, it is conceivable that the intermediate material is only selectively bonded to the carrier. The third layer of the sliding shoe according to the invention forms the sliding layer, the basic component of which is graphite. This upper layer is usually less thick than the intermediate material. The sliding layer therefore fulfills a sliding function for the grinding belt.

For receiving the abrasive shoe according to the invention, a sanding shoe carrier, hereinafter referred to as a sanding shoe mount, is also available.

This abrasive shoe holder, as the name already describes, supports the inventive sanding shoe and fixes it in a simple and advantageous manner.

The grinding shoe holder is connected via a receptacle with a carrier receiving rail of the belt grinding machine.

Essential to the grinding shoe holder is the new device for receiving and fixing the sanding pad. For this purpose, the sanding shoe holder has expansion elements. These expansion elements are arranged in corresponding fixing chambers and expandable by the introduction of an expansion medium. By introducing an expansion medium into the interior of the flexible expansion elements, these expand and expand into the space provided for expansion.

The expansion medium to be introduced may be a gas, a gas mixture or a suitably usable liquid.

If the sanding shoe with the free ends of the support is inserted via slot-shaped openings into the fixing chamber of the sanding shoe holder, the sanding shoe is fixed there via the expansion elements brought to expansion. In another embodiment, it may also be provided that the grinding shoe can be fixed in the carrier without the expansion of the fixing chambers. For this purpose, the sanding pad on appropriate dimensions that it can be fixed in the carrier by inserting. The fixing chambers are used in the presence then as an additional double backup. Should a double backup not be necessary in individual cases, then the sanding pad can be kept without expansion of the fixing chambers in the carrier.

Advantageously, this is done by extending the expanding expansion elements in the corresponding expansion space and there press the free ends of the wearer of the sanding pad to an inner wall of the fixing chamber. As free ends of the carrier or carrier strip, the two-sided free surfaces of the carrier are referred to, which are not covered by the intermediate material and the sliding layer.

The expansion elements have corresponding devices with which the control of the supply or the outlet of the expansion medium takes place. These may, for example, be valves or other controllable inlet and outlet devices.

A corresponding pressure-generating device can be integrated in the belt grinding machine, or be present as an additional device. This can be handled differently depending on the application.

In a preferred embodiment, the abrasive shoe holder according to the invention has chamfers on both sides of the contact surface which, depending on the application and abrasive belt, can occupy an area of ⅛ to ¼ of the contact surface. As bevel comes here also a rounding or flattening into consideration.

These chamfers cause the contact surface is not flat, but formed angled. The essential advantage of this is that the bevels or the angled shape of the contact surface are transferred to the flexible sanding shoe. By transferring the angled shape of the contact surface provided by the chamfers, the edges of the abrasive belt indicator are forced to flatten. The flattening of those edges is of particular importance, as with a non-flattened edge, first the sanding pad and then the sanding belt are often damaged. In order to achieve a flattening of the edges of the intermediate material or the sliding layer, previously very expensive and expensive additional processing steps were necessary. For example, the edges of the intermediate material were sanded before the layer was placed with the sliding layer, so that an angled form with flattened edges.

This complex processing of the edges of the sanding pad is now eliminated by the combination of the inventive sanding pad with the flexible support of, for example, textile fabric, paper, cardboard, soft plastic film of PU foam or textile fabric, or a mixture of these materials and the sanding belt recording with the Fixing chambers and the angled contact surface.

Furthermore, of course, it is also conceivable that the grinding shoe holder does not have above-mentioned chamfers and thus a flat contact surface. This may still be advantageous for individual sanding shoes and special sanding operations.

For easy replacement of the inventive abrasive shoe after its wear, or because another sanding pad is required, a corresponding device, such as an exhaust valve, for example, via a computer-aided control, so that the expansion medium, such as compressed air, can escape from the expansion element. As a result, the expansion element contracts in the fixing chamber and releases the free strips of the support of the grinding shoe, which was previously pressed against an inner wall. The sanding pad can now be removed from the sanding shoe holder or the belt sanding machine.

Thereafter, a new sanding pad is placed on the contact surface of the sanding shoe holder and inserted with the free strips of the carrier over the slot-shaped openings in the fixing chambers of the sanding shoe holder.

When this is done, the expansion element is filled by a computer-aided command by means of a corresponding device, such as a supply valve, with a corresponding expansion medium, such as compressed air, whereupon the expansion medium expands again and presses the free strip of the carrier to an inner wall of the fixing chamber via the expansion chamber, so sets and protects against slipping.

Furthermore, of course, it is also conceivable that the control of the expansion elements can be done manually. A combination of manual and computer-aided control is possible.

In addition, the expansion element delivery device and outlet device may also be combined in a combined device.

By this inventive method in conjunction with the inventive sanding pad and the sanding shoe recording, numerous disadvantages that hitherto related to the prior art are eliminated.

Furthermore, the present invention simplifies the production of sanding shoes and saves time and money by saving previously necessary operations, such as sanding the edges of the intermediate material. This is especially true for the substitution of expensive metal by, for example, cheaper textile fabric or, for example, hard paper. In this context, it has been found that ABS (acrylonitrile-butadiene-styrene) and wood are also suitable as the material for the carrier. Ultimately, it is important that the wearer's material have sufficient flexibility to cope with the functional features 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 das 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 inventive abrasive shoe by the substitution of the previously used metal or hard plastic such as ABS by, for example, hard paper for the wearer of the sanding pad, be disposed of easily and conveniently by a combustion process. A complex disposal or supply for recycling is eliminated.

1. 1. The sanding pad is pushed into the sanding shoe holder.
2. 2. By clamping the sanding belt, the sanding pad is pressed onto the contact surface of the sanding shoe holder. Thus, the sanding pad is evenly stretched in the sanding shoe receiving over the contact surface.
3. 3. With the help of, for example, compressed air, the expansion element is expanded and thus fixed the sanding pad in the sanding shoe holder.
4. 4. When changing the sanding shoe, the expansion element is released by releasing the expansion medium, for example compressed air, and the sanding pad can be pulled out.

In another embodiment, a sheet-like 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 abrasive shoe carrier and connected to a machine software.

The elastic insert then sits exactly on this support surface or contact surface and in a load case as it is during grinding, the pressure generated and the exact distribution of pressure over the support surface or contact surface in the software is displayed. The use of such a surface sensor is only possible with an elastic carrier. For a rigid support, the pressure would not be punctiform but would spread throughout the rigid support.

In contrast, in the exemplary embodiment shown here, the middle layer (foam) lies directly on the surface sensor. A significant advantage would be given by the fact that with an uneven pressure distribution on the inserts, as for example it is the case when the upper and lower insert in the machine are not parallel to each other or the insert is wrong, the pressure distribution over the entire bearing surface or contact surface on a display and the operator would know immediately if he has to re-set the inserts or correct their position. Until now, the adjustment can be controlled only with a complex process, such as with the help of a bearing ring, ruler or the like.

Overall, the area sensor is only an option that does not necessarily have to be provided.

figure 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 will become apparent from the following description of preferred embodiments and from the drawings; these show in:

• FIG. 1 a sectional view of a sanding shoe holder 5 with a sanding pad 1,
• FIG. 2 a sectional view of a sanding shoe holder 5.1 a sanding pad 1.1.

In FIG. 1 is a sectional view of an embodiment of a sanding shoe holder 5 with inserted inventive abrasive shoe 1 can be seen.

The sanding pad 1 consists of three layers. In the middle, an intermediate material 3 is arranged. On the one hand, the intermediate material 3 is made of the hard paper carrier 2. On the other hand, the intermediate material 3, a further layer is applied, which is referred to as a sliding layer 4. The intermediate material 3 and the sliding layer 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 holder 5 has on the side O via a contact surface 9, on which the sanding pad 1 rests. On the contact surface 9 on the one hand, a first chamfer 10 and on the other hand, a second chamfer 10.1 are arranged. This gives the contact surface 9 an angled shape. This angled shape of the contact surface 9 is transferred to the overlying sanding pad 1, since this has a flexible support. As a result of this effect, the outer edges of the intermediate material 3 and of the sanding belt indicator 4 bend slightly downward in the direction of a side U.

The first chamfer 10 and the second chamfer 10.1 mark the respective transition to the two-sided and mirror-image arranged fixing chambers 7 and 7.1. Via a slot-shaped opening 17 or 17.1, the two carrier strips 16 and 16.1 of the carrier 2 of the sanding pad 1 are inserted into the fixing chambers 7 and 7.1 of the sanding shoe holder 5.

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

Between an inner wall 13 and 13.1 and the expansion element 6 and 6.1 respectively an expansion space 8 and 8.1 is arranged.

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

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

This in FIG. 2 illustrated embodiment of the invention shows an inventive sanding pad 1.1 and a sanding shoe holder 5.1.

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

Due to the continuous flat shape of the contact surface 9.1 of the sanding pad 1.1 will not bend in the direction U. In order for an angled formation of the grinding shoe 1.1 resting on the sanding shoe receptacle 5.1 to be achieved, the intermediate material 3 has ground edges 11, 11.1. <B> LIST OF REFERENCES </ b> 1, 1.1 sanding pad U page 2 carrier O page 3 intermediate material 36 4 Sanding belt indicator 37 5, 5.1 Grinding shoe receiving 38 6, 6.1 expansion element 39 7, 7.1 Fixing chamber 40 8, 8.1 expansion space 41 9, 9.1 contact area 42 10, 10.1 chamfer 43 11, 11.1 edge 44 12, 12.1 expansion core 45 13, 13.1 inner wall 46 14 admission 47 15 recess 48 16, 16.1 carrier strip 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 (3)

1. Sanding shoe (1, 1.1) for a belt sanding machine, consisting of a sliding layer (4), the basic constituent of which is graphite, which fulfils a sliding function for the abrasive belt,
   an intermediate material (3)
   and a carrier (2) for inclusion in an sanding shoe holder, wherein the carrier (2) consists of a flexible material, and wherein the carrier (2) has two free ends or carrier strips which are not covered by the intermediate material and the sliding layer (4),
   characterised in that
   the flexible material is made of textile fabric, hard paper, paper, cardboard, soft plastic film made of PU foam or a mixture of these materials.
2. Method for the automated or manual fixing and releasing of a sanding shoe (1, 1.1) according to claim 1 with a carrier (2) in a sanding shoe holder (5, 5.1) with a fixing chamber (7, 7.1) with the following steps:

   - the carrier (2) of the sanding shoe (1, 1.1) is introduced into the fixing chamber (7, 7.1);

   - an expansion element (6, 6.1) in the fixing chamber (7, 7.1) is expanded by supplying an expansion medium into an expansion space (8), 8.1);

   - the carrier (2) is thereby pressed against an inner wall of the fixing chamber (7, 7.1).
3. Method according to claim 2, characterized in that the supply and removal of the expansion medium is controlled via a computer or a machine control or a manual operation.

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