EP4375453A1 - Tool for finishing and smoothing joints - Google Patents

Abstract

The present invention shows a tool (10) for reworking and smoothing joints filled with a joint compound, comprising a substantially plate-shaped body (12) with at least three end faces (1, 2, 3) that preferably run perpendicular to the plane of the plate and/or are each delimited by two lateral edges (6), of which a first end face (1) has a flat profile and a second end face (2) has a convex profile. It is provided that a projection (20) is arranged on a third of the three end faces (1, 2, 3), which projects from the third end face (3) and has a rounded end section (22).

Description

The present invention relates to a tool for reworking and smoothing joints filled with a joint compound, according to the preamble of claim 1.

Such joints come in a wide variety of shapes and sizes, for example between tiles or between a pane of glass and a frame, and are usually filled with elastic joint compounds such as mortar or silicone for sealing purposes. The joint compound is typically introduced into the joint in a deformable state and hardens after a while. Various tools are known from the state of the art to smooth the joint compound and give the final joint a pleasing visual appearance.

The EP 0 711 887 A1 a tool for reworking joints, which consists of a plate with a surrounding edge that protrudes perpendicularly to the plate plane on both sides. The plate has an essentially triangular shape, with one of the front sides being curved and two of the front sides being straight. The longer of the two straight front sides and the curved front side form an acute angle and merge into one another in an arc, so that this curved corner can be used to remove excess joint compound. and the creation of concave joint surfaces. The shorter of the two straight front sides and the curved front side also form an acute angle with each other, but merge into each other via a sharp or non-rounded edge, so that other joint surfaces can be achieved with this corner of the tool, especially between components that are perpendicular to each other.

The disadvantage of this tool, however, is that it is difficult to create joints in hard-to-reach places and often results in poor visual results. One challenge is, for example, grouting corners between three components that are perpendicular to each other, such as tiles that meet in the corner of a room. If the joint compound of the vertical joint is processed first and then the horizontal joint running across the corner is smoothed, part of the joint compound of the vertical joint is often removed. The same problem arises if the order is reversed.

To create dam-like joint fillings between perpendicular components, an additional front side can be created by "capping" a right-angled corner of the tool, as shown in the EP 1 666 683 A1 is disclosed. The additional edge and the adjacent front sides of the tool are bevelled on one side so that they form a sequence of adjacent cutting edges that are intended to facilitate the removal of removed joint compound. However, joint processing with this solution remains complex and the handling of the tool is limited. In addition, with this geometry, removed joint material can fall off the tool and contaminate the area around the joint.

Against this background, the present invention is based on the object of specifying a tool for reworking and smoothing joints filled with joint compound, which avoids the aforementioned disadvantages of the prior art and enables simple, flexible and effective joint processing.

This object is achieved according to a first aspect of the present invention by a tool having the features of claim 1. Advantageous embodiments of the invention emerge from the subclaims and the following description.

Accordingly, a tool for reworking and smoothing joints filled with a joint compound is proposed, which comprises a substantially plate-shaped body. The body comprises at least three end faces. These preferably each run perpendicular to the plate plane (i.e. to the plane along which the substantially plate-shaped body extends) and/or are each delimited by two lateral edges, which preferably run parallel to one another. Of the three end faces, a first end face has a flat or level profile and a second end face has a convex, i.e. convexly curved profile. The body preferably has three end faces and/or preferably an essentially triangular shape overall.

According to the invention, a projection is arranged on a third end face of the three mentioned end faces, which projection protrudes from the third end face. The projection has a rounded end section, i.e. the end of the projection protruding from the third end face is at least partially rounded. The end section is preferably rounded not only in one direction, but in several directions, so that an overall curved end section results.

In particular, the end portion can have a rounded shape both in a cutting plane which runs parallel to the plate plane and in a cutting plane which runs perpendicular to the plate plane.

The end section of the projection preferably has an ellipsoidal shape at least in sections, ie the surface of the projection has in the region of the end section at least in sections a profile that is curved in accordance with the surface of an ellipsoid. Such a surface profile is characterized in that the surface in this section has a positive curvature in more than one direction of curvature or a Gaussian curvature greater than zero. The ellipsoidal shape of the projection also includes a spherical shape, ie the end section of the projection can have, at least in sections, a surface profile that corresponds to a spherical surface.

The rounded or curved projection enables easy and gentle processing of joints that do not run in a common plane and meet at a common point, e.g. at corners between three tiles that are perpendicular to each other, as is often found in sanitary areas. The rounded shape of the projection means that a previously smoothed vertical joint is not damaged when the horizontal joints are subsequently smoothed (or vice versa), as the projection is not only curved along the direction of movement of the tool when smoothing the horizontal joint, but also transversely in the direction of the vertical joint. This multi-dimensional curvature of the projection prevents the already smoothed joint compound from being "scraped out".

The projection according to the invention is therefore particularly suitable for reworking joints in corners and in hard-to-reach places where several joints meet. Of course, the projection can also be used to smooth conventional joints outside corner areas.

The rounded projection can have a wide variety of shapes. For example, the projection can be designed as a partial sphere (i.e. a sphere cut off at a certain height, such as a hemisphere) that borders directly on the third end face. The curved or rounded section of the projection does not have to be spherical, but can also have the surface of a true ellipsoid in which two or all three semi-axes differ from one another. Another possibility is that the projection has a flat section on its upper side (spaced from the third end face) that is surrounded by one or more curved sections. A parabolic curvature or a rounded Forms that correspond neither to an ellipsoid nor to a parabola nor to any other analytically describable geometry are conceivable.

In one possible embodiment, the projection protrudes from the third end face along the plane of the panel or extends from the third end face along the plane of the panel. This makes it particularly easy to reach joints in corner areas and other hard-to-reach places that are to be worked on using the projection. The projection preferably protrudes perpendicularly from the third end face. This means in particular that the projection has a longitudinal axis that extends along the plane of the panel and in particular protrudes perpendicularly from the third end face. In the case of a projection that is rotationally symmetrical in plan view, said longitudinal axis can be an axis of symmetry of the projection or generally an axis that runs through one or more planes of symmetry of the projection.

In a further possible embodiment, it is provided that the third end face borders on the first and/or second end face and the projection is arranged in an area of the third end face bordering on the first or second end face. The projection can preferably merge continuously into the first or second end face, so that no joint compound can be deposited in any gaps between the projection and the end face. In addition, a continuous joint processing surface is created, which makes handling easier. The side of the projection that is flush with the first or second end face can optionally have a curved course, which in the case of the second end face preferably follows the curvature of the second end face. Optionally, the projection can have a maximum width perpendicular to the plate plane that essentially corresponds to the maximum width of the first or second and/or third end face.

Alternatively, the projection can be designed in such a way that it does not fit flush with the first or second end face, but protrudes beyond the first or second end face. For example, the projection as a whole could have the shape of a truncated Ball that extends slightly over the corner edge between the first or second and third end faces and possibly also over the side edges of the third end face. This ensures that when reworking joints, the side edges of the end faces do not touch the joint compound and scrape it out.

In a further possible embodiment, the projection and the body are formed in one piece. The tool is preferably made of an elastic plastic, in particular a thermoplastic or elastomer, in order to achieve sufficient flexibility to adapt the tool to different joint shapes as well as sufficient strength at the edge and sufficient abrasion resistance.

In a further possible embodiment, it is provided that the end section of the projection directly borders the third side surface. In order to increase the distance of the rounded area or end section from the third end face and thereby achieve better accessibility of corners, the end section can also be further away from the third end face and merge into the third side surface via an intermediate section. The intermediate section can, for example, be cylindrically shaped, which includes a circular cylindrical shape as well as an elliptical cylinder (i.e. a cylinder with an elliptical cross-section) or a cylinder whose cross-section includes both straight and curved or rounded sections. Instead of a cylindrical shape, the intermediate section can also be conical in shape, with the intermediate section preferably tapering towards the end section. The cross-section of the conical section can correspond to a circle or an ellipse or can include both straight and curved sections.

According to a second aspect of the present invention, which may also represent a further possible embodiment of the first aspect of the invention, but is also independent of this subject matter of the present invention, the body has an additional cutting edge which is at an angle to the first Front side runs continuously between the first or second front side and the third front side. The cutting edge preferably also runs at a certain angle to the third front side and forms a "clipped corner" between the first or second front side and the third front side. This additional working edge allows the tool to form dam-like joints between components that are perpendicular to one another, such as a pane of glass and a frame, and to remove excess joint material with pinpoint accuracy. The third front side preferably has a flat profile, although an arched profile for the third front side is also conceivable. In the latter case, the type of formation of the dam-like joint depends on which of the two front sides adjacent to the cutting edge the tool is placed on during production of the joint.

The cutting edge is preferably formed by the first or second end face and the third end face each tapering from their two lateral edges towards the middle. The cutting edge is therefore not as in the EP 1 666 683 A1 shown is a continuation of the already existing bevel of a front side, but the taper takes place from both sides of the front sides that do not form a cutting edge towards the middle, so that the cutting edge as a whole runs centrally in relation to the lateral edges of the front sides. This makes it possible to use the tool according to the invention to remove joints from both sides or in different directions, which increases the ease of use and the flexibility of handling the tool, while still achieving sufficient stability in the area of the cutting edge. The cutting edge preferably runs in a middle plate plane, which divides the body into two equal-sized and in particular symmetrical halves.

The cutting edge preferably forms an obtuse angle (90° ≤ α < 180°) with the first end face or second end face and/or with the third end face. The cutting edge preferably has no kink or curvature, but runs linearly between the first or second end face and the third end face.

Preferably, the lateral edges of the first, second and third end faces run parallel to one another everywhere except for the tapers forming the cutting edge. Only in the area of the cutting edge, where the first and third end faces taper towards the middle, do the lateral edges of the first or second end face and the third end face not run parallel, but rather run towards one another at an acute angle.

The length of the cutting edge is preferably less than the length of the first or second end face and/or the third end face. The length of the cutting edge may also be less than the width of the first or second end face and the third end face (outside the tapered sections).

In a further possible embodiment, it is provided that the first or second end face tapers towards a first end point and the third end face tapers towards a second end point, wherein the cutting edge runs linearly between the first and second end points. The two end points preferably lie in the middle plate plane described above.

In a further possible embodiment, the body has two opposite side surfaces, which are each delimited by the lateral edges of the first, second and third end faces (and the cutting edge, if present). The side surfaces are preferably identical, so that the tool according to the invention preferably has a mirror-symmetrical shape overall. This means that the tool can be used from both sides or joints can be removed in both directions.

In a further possible embodiment, the side surfaces each comprise a concavely shaped area which is at least partially surrounded by a seam. The concave areas can serve as handles or gripping surfaces and thus increase the ergonomics when holding and guiding the tool. In addition, the concave areas Removed joint material so that it does not fall off the tool when working on the joints and contaminate the area around the joint.

The circumferential seam has a flat profile and preferably a constant width and at least partially surrounds the respective concave area. To the outside, the seam of a side surface is limited by the respective lateral edges of the first, second and third end faces, while the seam preferably merges continuously inwards (i.e. towards the middle of the respective side surface), i.e. in particular without an abrupt step or 90° edge, into the concavely shaped area.

On the one hand, the seam serves to stiffen the body at its edges, so that stable edge areas or front sides are created that do not break or break away after only a little use. In addition, the seam running around the concave area of a side surface encloses any joint material that has accumulated or accumulated in the concave area, so that this can be removed from the body after use or at regular intervals. Because the seam continues continuously into the concave area and there is no sharp edge, no joint material can settle there and dry out, which would be difficult to remove.

In a further possible embodiment, the side surfaces in the area of the cutting edge are beveled flat towards the latter, with the bevels forming the previously described tapers of the first or second and third end faces. The cutting edge and the said tapers of the end faces are thus formed in particular by the bevels running from the two side surfaces to the center of the body in the corner areas between the first or second and third end faces. The bevels can have a substantially triangular shape.

The two bevels and thus in particular also the respective tapered lateral edges of the first or second and third end faces preferably enclose an acute angle (0° < α ≤ 90°) with each other.

In a further possible embodiment, the bevels run from the cutting edge into the concavely shaped areas of the side surfaces, i.e. the peripheral seam is interrupted by the respective bevel. As a result, in a plan view of the cutting edge along the middle plate plane, the upper and lower edges of the bevels that do not run parallel to the first or second and third end faces (i.e. the edges between the bevels and the concave areas) have a concave profile. The peripheral seam of each side surface is preferably only interrupted by the respective bevel and otherwise runs continuously around the concave area.

The concave shape of these upper and lower edges of the bevels is due to the fact that the bevels extend into the concave areas of the side surfaces. These concave indentations in the bevels ensure that when joint material is removed using the additional cutting edge, the removed material can reach the concave areas of the side surfaces. These indentations in the bevels, which function as "channels", allow excess joint material to "flow" more easily into the concave areas of the side surfaces.

In a further possible embodiment, it is provided that the third end face has a flat profile at least in sections, in particular overall. Preferably, the third end face (or in the case of an only partially flat profile of the third end face, the imaginary extension of this flat section) intersects the second or first end face at an obtuse angle.

In a further possible embodiment, it is provided that the third end face forms an acute angle with the first or second end face.

As a result, the projection arranged on the third end face is offset backwards or towards the middle of the body relative to the corner or the transition between the first or second and the third end face in relation to a perpendicular to the first or second end face, so that the projection does not hit or get in the way when processing joints with a working edge other than the end section of the projection. The transition between the first or second and the third end face is preferably formed by the cutting edge described above. The acute angle between the first or second and the third end face means that joints can be processed with the cutting edge without the projection hitting one of the components.

Regardless of its course, the third end face is preferably shorter than the first and/or second end face.

In a further possible embodiment, it is provided that the first and second end faces continuously merge into one another over a curved area, i.e. the transition or the "corner" between the first and second end faces is not a sharp edge, but rounded. The curved area has a curvature with a smaller radius of curvature than a curvature of the second end face, i.e. the curved area is more curved than the second end face. The curved area can represent an end of the body opposite the third end face.

The continuous transition of the curvature from the small radius of curvature of the rounded corner to the larger radius of curvature of the curved second face allows a variable recess of the smoothed joint as required. For example, the second face of the tool according to the invention can be used to create floor joints due to the comparatively large radius of curvature, while the more curved area or the rounded corner between the first and second In comparison, smaller rounded joints can be produced on the front sides, such as bathroom or balcony joints.

The previously described projection on the third end face of the tool preferably has a curvature along the plane of the panel with a smaller radius of curvature than the curvature of the curved area between the first and second end faces, i.e. the rounded end section of the projection is preferably more curved parallel to the plane of the panel than the said curved area. Rounded joints such as bathroom or balcony joints can also be produced with the curved projection.

In a further possible embodiment, it is provided that the body has an inner cavity, which can be filled with air, for example. This makes it possible to design the tool according to the invention in such a way that it floats in water and does not sink. This effect can also be achieved as an alternative or in addition to a cavity filled with a gas or a liquid by the body, which is made of a first material (e.g. a first thermoplastic or a first elastomer), having an inner region made of at least a second material (e.g. a second thermoplastic or a second elastomer) and at least partially enclosing it. It is conceivable, for example, to use a two-component injection molding. The various materials can be selected in such a way that the body has a stable, elastic structure that enables good joint processing, while at the same time the second material ensures that the tool floats.

Figur 1:

das erfindungsgemäße Werkzeug gemäß einem ersten Ausführungsbeispiel in einer Seitenansicht;

Figur 2:

das erfindungsgemäße Werkzeug gemäß einem zweiten Ausführungsbeispiel in einer Seitenansicht;

Figur 3:

das Werkzeug gemäß Figur 1 in einer Draufsicht auf die dritte Stirnseite;

Figur 4:

das Werkzeug gemäß Figur 2 in einer Draufsicht auf die dritte Stirnseite; und

Figur 5:

eine schematische Skizze der Schnittkante des erfindungsgemäßen Werkzeugs in einer perspektivischen Draufsicht auf die Schnittkante.

Further features, details and advantages of the invention emerge from the embodiments explained below with reference to the figures. They show:

Figure 1:

the tool according to the invention according to a first embodiment in a side view;

Figure 2:

the tool according to the invention according to a second embodiment in a side view;

Figure 3:

the tool according to Figure 1 in a plan view of the third front side;

Figure 4:

the tool according to Figure 2 in a plan view of the third front side; and

Figure 5:

a schematic sketch of the cutting edge of the tool according to the invention in a perspective top view of the cutting edge.

In the Figure 1 a first embodiment of the tool 10 according to the invention is shown in a side view. The tool 10 comprises a substantially plate-shaped and substantially triangular body 12, which can be made of an elastic plastic such as a thermoplastic or an elastomer. The body 12 has a first end face 1 with a flat or straight profile, a second end face 2 with an arcuate, more precisely convexly curved profile, and a third end face 3 with a flat or straight profile. In the embodiment, the end faces 1, 2, 3 run perpendicular to the plate plane along which the body extends, and have a constant width perpendicular to the plate plane (except for the area of the bevels 30, which will be discussed further below).

In an alternative embodiment, the second end face 2 could have a flat or straight profile and the first end face 1 could have an arcuate or convexly curved profile. Furthermore, the third end face could be curved.

As exemplified in the Figure 3 which shows a top view of the third end face 3, the end faces 1, 2, 3 are each connected by two lateral edges 6, which (except for the area of the bevels 30) run parallel to each other and in the embodiment of the Figures 1 and 3 define the maximum width of tool 10.

The body 12 has two side surfaces, one of which is in the Figure 1 shown in plan view. The side surfaces each have a concavely shaped region 14 which is surrounded by a flat seam 16 with preferably constant width towards the edges 6 of the end faces 1, 2, 3. The seam 16 is only interrupted by bevels 30, as will be explained later.

The second end face 2 can have a constant curvature over its entire course, although a course with varying curvature is also conceivable. The second end face 2 merges continuously into the straight first end face 1 via a curved region 5, the region 5 being more curved than the second end face 2 and thus forming a rounded corner of the essentially triangular tool 10. It can be provided that the first end face 1 encloses an acute angle with each tangent adjacent to the second end face 2 (outside the curved region 5).

Due to the first and second end faces 1, 2 converging and ending in the curved region 5, i.e. due to the shape of the body 12 tapering towards the curved region 5, it is generally possible to process joints even in spatially difficult to access areas.

At its end opposite the curved region 5, the second end face 2 borders on the third end face 3 and preferably forms an obtuse angle of e.g. 90-120° with the latter at the transition. In an area in which the third end face 3 borders on the second end face 2, the third end face 3 has a projection 20 which projects outwards from the third end face 3. The statement that the third end face 3 forms an obtuse angle with the second end face 2 at the transition refers to the imaginary extension of the third end face 3 through the projection 20 and neglects its course.

According to the invention, the projection 20 has a rounded end section 22, which enables gentle processing of joints in corner areas. In the embodiment of the Figures 1 and 3 the end section 22 has, in sections, essentially the shape of an ellipsoid, more precisely, essentially the shape of a hemisphere (as a special case of a (partial) ellipsoid). The end section 22 merges seamlessly or without edges into an intermediate section 24, which in the present embodiment has a conical shape with a circular cross-section and, starting from the end section 22, widens slightly towards the third end face 3 and merges into it. The Figure 3 shows the projection 20 in a top view. In the Figure 1 It can also be seen that the projection 20 continuously borders on the second end face 2 or merges into it. As a result, no excess joint compound can accumulate and dry in the area of the projection 20.

Of course, other shapes of the projection are conceivable, which also enable reworking of joints in corner areas, for example projections with a cross-section in the form of a true ellipse or projections which, in plan view, are extended over a straight section in one direction (e.g. lengthwise or transversely to the lateral edges 6 of the third end face 3).

Another possibility for designing projection 20 is in the Figures 2 and 4 shown using a second embodiment, wherein the Figure 2 a side view of the body 12 and the Figure 4 shows a plan view of the third end face 3. The second embodiment differs from the first embodiment only in the shape of the projection 20, so that the other features of the tool 10 will not be discussed again.

In the second embodiment, the projection 20 has the shape of a ball, more precisely a flat cut ball, which borders with the flat cut side on the third end face 3. This description serves in particular for the purpose of mere geometric illustration and says nothing about the manufacture of the tool 10. Preferably, the projection 20 is formed in one piece with the body 12 (also in the first embodiment). In this case, the projection 20 essentially consists of the rounded end section 22, while no intermediate section 24 is provided. In the second embodiment shown here, less than half of the ball is "cut off", so that the projection 20 at its widest point protrudes beyond the edge between the second and third end faces 2, 3 and beyond the lateral edges 6 of the third end face 3. Of course, it is also conceivable to form the projection 20 as a hemisphere or as a ball with a smaller volume than a hemisphere.

In both embodiments, the projections 20 are rotationally symmetrical, with the axis of rotation being perpendicular to the third end face 3.

In the Figures 1 and 2 It can be seen that in the embodiments shown here, the radius of curvature of the projection 20 parallel to the plate plane is smaller than the radius of curvature of the opposite curved region 5, so that different joint shapes or radii can be achieved in each case.

In the area of the transition between the first end face 1 and the third end face 3, an additional working edge in the form of a cutting edge 4 is provided, which represents a quasi-cut corner between the first and third end faces 1, 3 and extends continuously between these two end faces 1, 3.

In the embodiments discussed here, the third end face 3 forms an acute angle with the second end face 2, with the cutting edge 4 preferably forming an obtuse angle with both the first and the third end face 1, 3. In addition, the cutting edge 4 has a linear profile.

The Figure 5 shows a top view of the cutting edge 4 looking along the plane of the plate. The first and third end faces 1, 3 can be seen, the parallel lateral edges 6 of which taper towards the middle of the plate or converge at a preferably acute angle, thereby forming the cutting edge 4. The cutting edge 4 thus runs in a middle plate plane, which divides the body 12 into two symmetrical halves.

As can be seen in the figures, the tapering of the first and third end faces 1, 3 and the cutting edge 4 are formed by the body 12 being bevelled on the side surfaces in the area of the corner or the transition between the first and third end faces 1, 3 from both sides towards the middle of the plate. The essentially triangular bevels 30 begin on the respective side surface in the concave area 14 and meet at the cutting edge 4. Because the bevels 30 extend into the concave areas 14 of the side surfaces, the edges 32 between the flat bevels 30 and the concave areas 14 (in the Figure 5 as upper and lower edges 32 represented by dotted lines) also have a concave course. The concave indentations of these edges 32 act as channels through which excess joint material can reach or "flow" into the concave areas 14 of the side surfaces when joint compound is removed using the cutting edge 4.

The seam 16, which preferably does not merge over an edge but continuously into the concave region 14, is only interrupted by the bevels 30 and otherwise completely surrounds the concave region 14.

List of reference symbols:

1

First front side

2

Second front side

3

Third front side

4

Cutting edge

5

Curved area

6

Side edge

10

Tool

12

Corpus

14

Concave area

16

hem

20

head Start

22

End section

24

Intermediate section

30

bevel

32

Edge

Claims (15)

Tool (10) for reworking and smoothing joints filled with a joint compound, comprising a substantially plate-shaped body (12) with at least three end faces (1, 2, 3) which preferably run perpendicular to the plane of the plate and/or are each delimited by two lateral edges (6), of which a first end face (1) has a flat profile and a second end face (2) has a convex profile,
characterized,
that on a third of the three end faces (1, 2, 3) a projection (20) is arranged, which projects from the third end face (3) and has a rounded end portion (22). Tool (10) according to claim 1, wherein the third end face (3) borders on the first or second end face (2) and the projection (20) is arranged in a region of the third end face (3) bordering on the first or second end face (2), wherein the projection preferably merges continuously into the first or second end face (2) or protrudes beyond the first or second end face (2). Tool (10) according to claim 1 or 2, wherein the end portion has a rounded shape both in a cutting plane which runs parallel to the plate plane and in a cutting plane which runs perpendicular to the plate plane. Tool (10) according to one of the preceding claims, wherein the projection (20) and the body (12) are formed in one piece and are preferably made of an elastic plastic, in particular thermoplastic or elastomer. Tool (10) according to one of the preceding claims, wherein the body has three end faces and/or an overall substantially triangular shape. Tool (10) according to one of the preceding claims or according to the preamble of claim 1, wherein the body (12) has a cutting edge (4) which runs at an angle to the first or second end face (1) continuously between the first or second end face (1) and the third end face (3) and is formed in that the first or second and the third end face (1, 3) each taper from their two lateral edges (6) towards the middle, wherein the cutting edge (4) preferably runs in a middle plate plane which divides the body (12) into two equal-sized and in particular symmetrical halves. Tool (10) according to claim 6, wherein the first or second end face (1) tapers towards a first end point and the third end face (3) tapers towards a second end point, the cutting edge (4) extending linearly between the first and second end points. Tool (10) according to one of the preceding claims, wherein the body (12) has two opposite side surfaces, which are each delimited by the lateral edges (6) of the first, second and third end faces (1, 2, 3) and are preferably of identical design. Tool (10) according to claim 8, wherein the side surfaces each comprise a concavely shaped region (14) which is at least partially surrounded by a circumferential seam (16) with a flat profile and in particular a constant width, wherein the seam (16) is delimited outwards by the lateral edges (6) of the first, second and third end faces (1, 2, 3) and preferably merges continuously inwards into the concavely shaped region (14). Tool (10) according to one of claims 6 to 7 and according to one of claims 8 to 9, wherein the side surfaces in the region of the cutting edge (4) are flatly bevelled towards the cutting edge (4), wherein the bevels (30) form the tapers of the first or second and third end faces (1, 3) and preferably enclose an acute angle with one another. Tool (10) according to claims 9 and 10, wherein the bevels (30) extend from the cutting edge (4) into the concavely shaped regions (14) of the respective side surfaces, so that in a plan view of the cutting edge (4) along the central plate plane, the upper and lower edges (30) of the bevels (30), which do not run parallel to the first or second and third end faces (1, 3), each have a concave profile. Tool (10) according to one of the preceding claims, wherein the third end face (3) has a flat profile at least in sections, in particular overall, wherein preferably an imaginary extension of a flat section of the third end face (3) intersects the second or first end face (2) at an obtuse angle. Tool (10) according to one of the preceding claims, wherein the third end face (3) forms an acute angle with the first or second end face (1). Tool (10) according to one of the preceding claims, wherein the first and second end faces (1, 2) continuously merge into one another over a curved region (5), wherein the curved region (5) has a curvature with a smaller radius of curvature than a curvature of the second end face (2), wherein the tool (10) preferably has a projection (20) according to one of claims 1 to 5 and a curvature of the projection (20) along the plate plane has a smaller radius of curvature than the curvature of the curved region (5). Tool (10) according to one of the preceding claims, wherein the body (12) has an inner cavity and/or is made of a first material which at least partially encloses an inner region made of a second material.

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