Fastening device

Abstract

The invention relates to a fastening device for fastening a grinding and / or polishing plate (20) to a tool receptacle (12) of a power tool (10), in particular a tool receptacle (12) of an angle grinder, comprising at least one carrier plate (16) for holding and / or supporting the grinding and / or polishing plate (20), said carrier plate having a through-hole (17); and a clamping sleeve (18) for inserting into the through-hole (17) and for forming a frictional engagement between the grinding and / or polishing disc (20) and the carrier disc (16). According to the invention, the fastening device has at least one intermediate element (22) for arrangement between the clamping sleeve (18) and the grinding and / or polishing disc (20) in order to enhance the frictional engagement.

Description

Background Art

[0001] A fastening device for fastening a grinding disc on an angle grinder has been proposed. The fastening device has a fastening sleeve which presses the grinding disc directly onto a carrier disc. Summary of the invention

[0002] The invention relates to a fastening device for fastening a grinding and / or polishing disc to a tool receiving part, in particular a tool receiving part of an angle grinder, the fastening device having at least one carrier plate for holding and / or supporting the grinding and / or polishing disc, the carrier plate having a preferably central through hole, and a clamping sleeve for being inserted into the through hole and for forming a friction lock between the grinding and / or polishing disc and the carrier plate.

[0003] The invention proposes that the fastening unit has at least one intermediate element for being arranged between the clamping sleeve and the grinding and / or polishing disk in order to increase the frictional connection.

[0004] The embodiment of the fastening device according to the invention makes it possible to achieve good holding of the grinding and / or polishing pad.

[0005] "Grinding and / or polishing sheet" is to be understood as a consumable item, which is arranged to place an electric tool, especially an electric hand tool, with a tool receiving portion in motion. The grinding and / or polishing sheet can especially have a flexible carrier material, on which a grinding and / or polishing agent, especially a material of high hardness and / or low particle size is applied. Alternatively, the entire grinding and / or polishing sheet can be made of the same material. For example, the workpiece surface can be ground and / or polished by means of the grinding and / or polishing sheet. The grinding and / or polishing sheet can be configured as a fiber sheet and, for example, has a fiber material as a carrier material. The electric tool can be arranged to place the grinding and / or polishing sheet in a rotational and / or oscillating motion, especially around an axis of motion extending through a through hole and / or at least perpendicular to the extension of the grinding and / or polishing sheet.

[0006] The carrier disc can, for example, consist at least for the most part of rubber or a rubber-like material. The clamping sleeve is advantageously provided for at least fastening, in particular clamping, the carrier disc on the tool receptacle. The carrier disc can have a form-locking element which is provided for interacting with a form-locking element of the tool receptacle in order to form a rotationally fixed connection between the tool receptacle and the carrier disc, in particular with respect to the axis of movement. Alternatively, the carrier disc can be fastened to the tool receptacle only by force locking, in particular by means of the clamping sleeve, with respect to a rotational and / or oscillating movement about the axis of movement.

[0007] Preferably, the grinding and / or polishing sheet consists of a flexible material. The intermediate element may be arranged to partially offset and / or deform the grinding and / or polishing sheet. The intermediate element may offset the grinding and / or polishing sheet or a portion thereof so that the intermediate element extends below the grinding surface formed by the grinding disc. The intermediate element may be partially placed on the grinding surface. The grinding surface is defined, for example, by a surface of the carrier disc surrounding the through hole. Preferably, the grinding and / or polishing sheet is placed flat and / or planar on the carrier disc so as to form the grinding surface.

[0008] The clamping sleeve and / or the intermediate element are provided, for example, for fixing the grinding and / or polishing disc and / or the carrier disc on the tool receiving part in a form-locking manner relative to the direction along the axis of movement. The clamping sleeve can be made of a material different from that of the intermediate element. The clamping sleeve is preferably made of metal, in particular aluminum, tool steel or stainless steel. The clamping sleeve advantageously has a hollow cylindrical shape.

[0009] According to another embodiment, the clamping sleeve can have an interface for a tool-free, form-locking connection with a tool receiver. For example, the tool receiver is designed as an X-Lock tool receiver. This can in particular enable rapid tool assembly and / or rapid replacement of grinding and / or polishing pads.

[0010] The intermediate element is advantageously designed to be annular and surround the clamping sleeve. This can achieve a high durability in particular. According to an alternative, the fastening device can have, for example, a plurality of intermediate elements, which are arranged at different points around the clamping sleeve.

[0011] It is further proposed that the intermediate element is made of a deformable material. In particular, the intermediate element is provided to adapt its shape to unevenness of the grinding and / or polishing disc. Advantageously, at least one intermediate element is made of rubber or a rubber-like material. This can in particular achieve a high friction-locking reinforcement effect.

[0012] Furthermore, the intermediate element and the carrier plate can each have a contact surface for clamping the grinding and / or polishing pad between these contact surfaces. This can achieve a good friction fit in particular.

[0013] Preferably, the contact surfaces have conical surfaces that are complementary to one another. The two parts having "complementary" conical surfaces should be understood in particular to mean that the two parts each have a cone and that when the two parts are placed against one another, the cone of one part rests flush and over a large area on the cone of the other part. For example, the contact surface of the carrier plate surrounds the through-hole and is in turn surrounded by the grinding surface. The contact surface of the carrier plate can have such a cone that the further away the points of the contact surface are from the grinding plane on which the grinding surface lies, the closer they are to the through-hole. Thus, in particular a large contact surface and a good friction fit can be provided.

[0014] Furthermore, the clamping sleeve can have a radial projection on the outer end for transmitting the holding force from the clamping sleeve to the intermediate element and / or to the grinding and / or polishing disc. This can make it possible to achieve a large force transmission in particular. Advantageously, the intermediate element is designed separately from the clamping sleeve. The intermediate element can have a groove in which the radial projection engages.

[0015] According to an alternative embodiment, the clamping sleeve can be designed without radial projections and the at least one intermediate element can be fastened, in particular adhesively bonded, to the outer end of the clamping sleeve.

[0016] Furthermore, the invention proposes that the radial projection and the intermediate element have conical surfaces which are complementary to each other.

[0017] Furthermore, the cone of the contact surface can be steeper than the cone between the intermediate element and the radial projection. The steeper the cone, the smaller the cone angle between the cone generatrix and the axis of motion, wherein the cone generatrix intersects the axis of motion and extends parallel to the surface with the cone. Preferably, the contact surface has cones with the same cone angle around the axis of motion. Advantageously, the clamping sleeve and the intermediate element have cones with a constant cone angle around the axis of motion. According to an alternative embodiment, it is conceivable that the cone angles of the cones around the axis of motion are different.

[0018] The invention furthermore provides an electric tool, advantageously an electric hand tool, in particular an angle grinder, which has a fastening device as described above.

[0019] The fastening device according to the invention and the hand tool according to the invention are not to be limited to the applications and embodiments described above. In particular, the fastening device according to the invention and the hand tool according to the invention can have a number of individual elements, components and units that differ from the number described here in order to meet the working method described here. In addition, within the value range given in the present disclosure, the values ​​within the stated limits should also be regarded as disclosed and can be used arbitrarily. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Further advantages are apparent from the following description of the drawings. Embodiments of the invention are shown in the drawings. The drawings, the description and the claims contain features in a plurality of combinations. A person skilled in the art may also consider the features individually and combine them into other meaningful combinations.

[0021] Figure 1 : A schematic diagram of a power tool according to the invention with a fastening device according to the invention in a disassembled state;

[0022] Figure 2 :according to Figure 1 A schematic cross-sectional view of the fastening device in an assembled state;

[0023] Figure 3 : A schematic three-dimensional view of the clamping sleeve of the fastening device in the exploded state, viewed from below. DETAILED DESCRIPTION

[0024] Figure 1 The electric tool 10 is shown with a tool receptacle 12 and a fastening device 14 for fastening a grinding and / or polishing pad 20 to the tool receptacle 12. The electric tool 10 is designed as an electric hand tool. The electric tool 10 is designed as an angle grinder.

[0025] The fastening device 14 has a carrier plate 16 for holding and / or supporting the grinding and / or polishing pad 20. The carrier plate 16 has a through hole 17. The fastening device 14 also has a clamping sleeve 18 for insertion into the through hole 17 and for forming a friction fit between the grinding and / or polishing pad 20 and the carrier plate 16. The diameter of the through hole 17 is selected to be just large enough to allow the clamping sleeve 18 to be inserted flush.

[0026] The fastening device 14 has an intermediate element 22 which is arranged between the clamping sleeve 18 and the grinding and / or polishing pad 20 in order to increase the frictional connection.

[0027] The carrier plate 16 defines a grinding surface 24 (see Figure 2 ). The grinding and / or polishing pad 20 rests on the grinding plane 24 in the working area of ​​the carrier disc 16. The carrier disc 16 consists mostly of rubber and can have grooves and / or corrugations in the working area, in particular in order to achieve a variable contact pressure during operation and / or in order to form an improved friction fit with the grinding and / or polishing pad 20. In the assembled state, the carrier disc 16 can have a metal base on the side facing the tool receptacle 12 in order to better hold it on the tool receptacle 12.

[0028] The grinding and / or polishing disc 20 has a through hole 17'. The clamping sleeve 18 is provided for insertion through the through hole 17'. The through hole 17' is designed to be just large enough to allow the clamping sleeve 18 to be inserted flush, so that when mounted on the carrier disc 16 and / or the tool receiving part 12, the grinding and / or polishing disc 20 is centered on the carrier disc 16. The grinding and / or polishing disc 20 has a slot 21 extending radially from the through hole 17'. The slot 21 allows the grinding and / or polishing disc 20 to be deformed outward from the grinding plane 24.

[0029] The intermediate element 22 can offset the grinding and / or polishing pad 20 and / or at least one region of the grinding and / or polishing pad 20 between the gaps 21 , so that the intermediate element 22 and the clamping sleeve 18 are located outside the grinding plane 24 .

[0030] The clamping sleeve 18 has an interface 19 for a tool-free, form-fitting connection to the tool receiver 12 (see Figure 3 ).

[0031] The intermediate element 22 is annular and surrounds the clamping sleeve 18. The intermediate element 22 is made of a deformable material. The intermediate element 22 is made of rubber.

[0032] The intermediate element 22 and the carrier plate 16 each have a contact surface 26, 26' for clamping the grinding and / or polishing pad 20 therebetween. The contact surface 26 of the carrier plate 16 is arranged between the working area and the through hole 17. The contact surfaces 26, 26' have mutually complementary cones.

[0033] The clamping sleeve 18 has a radial projection 28 at the outer end for transmitting the holding force from the clamping sleeve 18 to the intermediate element 22 and / or the grinding and / or polishing pad 20 .

[0034] The radial projection 28 and the intermediate element 22 have conical surfaces 30 , 30 ′ which are complementary to one another. The cone of the contact surface 26 , 26 ′ is steeper than the cone 30 , 30 ′ between the intermediate element 22 and the radial projection 28 .

Claims

1. A fastening device for fastening a grinding and / or polishing disc (20) to a tool receiving portion (12) of an electric tool (10), in particular a tool receiving portion (12) of an angle grinder, the fastening device comprising: at least one carrier plate (16) for holding and / or supporting the grinding and / or polishing plate (20), the carrier plate having a through hole (17); and a clamping sleeve (18) for being inserted into the through hole (17) and for producing a friction fit between the grinding and / or polishing disc (20) and the carrier disc (16), Features At least one intermediate element (22) is provided, which is arranged between the clamping sleeve (18) and the grinding and / or polishing disc (20) in order to increase the frictional connection.

2. The fastening device according to claim 1, characterized in that: The clamping sleeve (18) has an interface (19) for a tool-free, form-fitting connection to the tool receiver (12).

3. The fastening device according to claim 1 or 2, characterized in that: The intermediate element (22) is annular in shape and surrounds the clamping sleeve (18).

4. Fastening device according to any one of the preceding claims, characterized in that The intermediate element (22) is made of a deformable material.

5. The fastening device according to claim 4, characterized in that: The intermediate element (22) is made of rubber or a rubber-like material.

6. Fastening device according to any one of the preceding claims, characterized in that The intermediate element (22) and the carrier plate (16) respectively have contact surfaces (26, 26') for clamping the grinding and / or polishing disc (20) between the contact surfaces (26, 26').

7. The fastening device according to claim 6, characterized in that: The contact surfaces (26, 26') have conical surfaces which are complementary to each other.

8. Fastening device according to any one of the preceding claims, characterized in that The clamping sleeve (18) has a radial projection (28) at the outer end for transmitting the holding force from the clamping sleeve (18) to the intermediate element (22) and / or to the grinding and / or polishing disc (20).

9. The fastening device according to claim 8, characterized in that The radial projection (28) and the intermediate element (22) have conical surfaces (30, 30') which are complementary to each other.

10. The fastening device according to claims 7 and 9, characterized in that The cone of the contact surface (26, 26') is steeper than the cone (30) between the intermediate element (22) and the radial projection (28).

11. An electric tool, in particular an angle grinder, having a fastening device (14) according to any one of the preceding claims.

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