Cutting tool having a rest with a preset sharpening angle

Abstract

The present invention relates to a cutting tool (1), particularly a knife, including at least one blade (2) having a blade cutting portion (2a) and a cutting edge (2b). To enable the cutting tool (1) to be sharpened and / or polished with high precision without the use of a sharpening jig, the cutting tool (1) of the present invention includes at least one mounting portion (4), which defines a mounting plane (AE) on which the cutting tool (1) can be stably placed on a flat underside (U) so that the blade cutting portion (2a) is oriented at a working angle (α) in the range of 65 to 80° relative to the flat underside (U) for sharpening and / or polishing the cutting edge (2b). A set for sharpening and / or polishing the cutting tool (1) and a corresponding method are also disclosed.

Description

[Technical field]

[0001] The present invention relates to a cutting implement, in particular a knife such as a chef's knife, comprising at least one blade having a blade cutting portion and a cutting edge. [Background technology]

[0002] For sharpening or polishing the cutting edge, sharpening or polishing tools with a rotating sharpening or polishing surface can be used. Such sharpening or polishing tools, also called "Rorschleifers" (rotary sharpeners), are known, for example, from DE 202020001180 A1 or EP 3278928 A1.

[0003] To position the blade relative to the sharpening or grinding tool, a so-called sharpening jig can be used, which positions the blade at a predefined sharpening angle relative to the sharpening surface, and sharpens the cutting edge at the sharpening angle determined by the sharpening jig.

[0004] There are three elements that must work together to achieve a satisfactory process result: cutting tool, sharpening fixture, and sharpening / polishing tool. This increases the logistical and coordination costs for users in the sharpening or polishing process of cutting tools. Summary of the Invention

[0005] To solve the above problems, the present invention provides a cutting tool according to claim 1, a set according to claim 8 and a method according to claim 10.

[0006] The cutting tool of the present invention is in particular a knife or kitchen knife, and comprises at least one blade having a blade cutting portion and a cutting edge, said cutting tool comprises at least one mounting portion, said mounting portion defining a mounting plane on which said cutting tool can be stably mounted on said lower surface portion so that said blade cutting portion (or the extension plane of the blade cutting portion) is oriented at a working angle in the range of 65 to 80° with respect to the flat lower surface portion for sharpening and / or grinding said cutting edge. The working angle refers to the angle between the blade cutting portion (or the extension plane of the blade cutting portion) and the mounting plane. When the mounting plane is placed on the lower surface portion, the working angle is the angle between the blade cutting portion (or the extension plane of the blade cutting portion) and the lower surface portion. The sharpening angle refers to the angle between the extension plane of the blade cutting portion and the sharpening surface. In the case of the Rörschleifer mentioned at the beginning, the sharpening surface rotates in a plane oriented perpendicular to the lower surface portion. Therefore, the sharpening angle β is calculated from the working angle α using the following formula I: Formula I: β=90°-α

[0007] In the present invention, "stable" means that the cutting tool is placed on the lower surface on the placement plane while maintaining the above-mentioned working angle even during the sharpening and / or polishing process. In this case, the user preferably holds the cutting tool by the gripping part and presses it against the lower surface on the placement plane. It is desirable, but not essential, that the cutting tool can be placed stably on the lower surface on the placement part independently, i.e. without the action of external forces. Preferably, when the cutting tool is placed on the lower surface on the placement part, the center of gravity of the cutting tool is located within the area of ​​the placement part (between the placement points) when projected onto the lower surface. However, in order to apply a counterforce to the force exerted on the blade by the sharpening / polishing tool during the sharpening or polishing process, it has been found to be advantageous for the user to fix the cutting tool and press it against the lower surface on the placement part during the sharpening or polishing process. During the sharpening or polishing process, the cutting edge of the blade is preferably arranged on the opposite side to the lower surface and the blade back is arranged on the lower surface side (see FIG. 4). In principle, however, it is also possible to arrange the rest on the cutting tool so that during the sharpening or grinding process the cutting edge of the blade faces the underside and the blade back is located opposite the underside. If the rest is adjusted during manufacture of the cutting tool or before the sharpening or grinding process begins, this allows the working angle to be set in the range of 65-80°. During the sharpening or grinding process, the working angle is preferably constant, so that the cutting edge is sharpened uniformly and sharply.

[0008] Advantageous refinements of the invention are described in the dependent claims.

[0009] A working angle in the range of 70-75° can be advantageous. In practice, sharpening angles of 15° or 20° have proven to be particularly advantageous. A sharpening angle of 15° is used to sharpen very sharp blades, such as fillet knives used to cut meat. A sharpening angle of 20° results in a less sharp cutting edge, but with less wear. Depending on the choice of a sharpening angle in the range of 15-20°, which corresponds to a working angle of 70-75°, the sharpness and wear characteristics of the cutting edge can be adjusted.

[0010] It may be useful that the cutting tool comprises a gripping body, the gripping body preferably having at least one of the mounting parts, the mounting part preferably being arranged on the opposite side of the gripping part from the cutting edge (e.g., on the back of the gripping part, etc.). In particular, during sharpening or polishing processing, a pressing force can be applied to the gripping body to press the cutting tool placed on the underside part on the mounting plane in the processing position against the underside part. In this way, the static friction between the cutting tool and the underside part can be improved.

[0011] It may be useful that the resting part has at least three resting points located in the resting plane, the resting points being not in line, and preferably at least 25%, 30% or 40% of the total length of the cutting tool is located between two of the resting points, the total length being preferably measured between the blade tip and the end of the gripping body opposite the blade tip, and preferably the distance between at least one of the resting points and the extension plane of the blade cutting edge is greater than 1%, 2% or 3% of the total length of the cutting tool. It is not the size of the resting part that is crucial for the stability of the arrangement, but rather the distance between the resting points in the resting plane, in particular the distance perpendicular to the extension plane of the blade cutting edge. Even if the cutting edge and the sharpening / polishing tool usually move relative to each other in or parallel to the extension plane of the blade, there is usually a force component during the sharpening or polishing process that acts transversely to the extension plane of the blade and pushes the blade and the cutting tool out of the defined processing position. A large contact area between the cutting tool and the underside increases the static friction of the cutting tool against the underside and stabilizes the cutting tool in the treatment position. It may be advantageous to make the rest part elastic, in particular to have a silicone coating. This configuration can further increase the static friction between the cutting tool and the underside.

[0012] It may be useful for the cutting tool to have two mounting parts arranged on different sides (of the extension plane) of the blade, each of which defines a mounting plane on which the cutting tool can be stably mounted on the flat underside so that the orientation of the blade (or its extension plane) relative to the flat underside is at the same working angle in order to sharpen the cutting edge. Such a configuration allows both sides of the cutting edge to be sharpened or ground particularly uniformly.

[0013] It may be convenient to arrange the rest part so that it is adjustably positionable on the cutting tool, which allows sharpening or honing the cutting edge at an individual sharpening angle depending on the use case.

[0014] Advantageously, the rest is adjustable between at least two different positions to vary the working angle, preferably such that when the rest is in a first position the working angle is 70° and when the rest is in a second position the working angle is 75°, such that in the first position the sharpening angle is 20° and in the second position the sharpening angle is 15°.

[0015] Another aspect of the invention relates to a set comprising a cutting tool of any one of the above embodiments and a sharpening and / or polishing tool having at least one sharpening and / or polishing surface that rotates in a plane oriented perpendicular to the lower surface as the sharpening and / or polishing tool rolls.

[0016] It may be advantageous if the sharpening and / or polishing tool comprises a cylindrical gripping body, the sharpening and / or polishing surfaces being arranged at each axial end of the gripping body. The above-mentioned shapes of sharpening / polishing tools are versatile and have proven to be particularly advantageous in practice.

[0017] Another aspect of the invention relates to a method for sharpening and / or polishing a cutting tool of any one of the above embodiments, comprising the steps of: - Step A: The cutting tool is placed on the lower surface on the placement plane so that the blade cutting portion is at a working angle of 65 to 80 degrees relative to the flat lower surface. Preferably, in this step, the user applies force to press the cutting tool against the lower surface with the placement portion so that the cutting edge faces away from the lower surface. - Step B: applying the cutting edge to a sharpening and / or polishing surface of a sharpening and / or polishing tool, which is oriented perpendicularly to the underside. Rorschleifer, as known, for example from EP 3 278 928 A1, comprises (a cylindrical body with) sharpening or polishing surfaces (at its two ends), which rotate in a plane oriented perpendicularly to a flat underside as the Rorschleifer rolls over the underside. Step C: Sharpening and / or polishing the cutting edge by moving the sharpening and / or grinding surface and the cutting edge relative to one another. Preferably, the cutting tool remains fixed in position relative to the lower surface while the sharpening / polishing tool moves along the length of the cutting edge as it rolls over the lower surface. The slight contact pressure between the cutting tool and the sharpening / polishing tool causes the sharpening or polishing surface to remove material from the blade during the relative movement, sharpening or polishing the cutting edge.

[0018] Further advantageous refinements of the invention result from the combination of what is stated in the description, the claims and the drawings. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic side view of a cutting instrument of the present invention in the form of a kitchen knife having a blade, a handle, and a mounting portion disposed on the handle, the mounting portion defining a mounting plane for mounting the cutting instrument on a flat underside. [Diagram 2] 2 is a schematic side view of the cutting instrument of FIG. 1, seen from another side. [Diagram 3] 2 is a cross-sectional view taken along the cross-sectional plane AA of FIG. 1; [Figure 4]FIG. 1 is a schematic front view of a cutting tool of the present invention, seen from the blade tip side, where the cutting tool is placed on a flat underside of one of the mounting surfaces as specified, with the blade cutting edge oriented at a predetermined working angle relative to the underside, and the cutting edge of the blade being treated with a sharpening and / or polishing tool. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0021] FIG. 1 is a side view of a cutting tool 1 of the invention configured as a kitchen knife. The kitchen knife 1 has a flat, elongated blade 2, which has a blade cutting edge 2a, a lower convexly curved cutting edge 2b, an upper straight blade back 2c, and a front tip 2d. The blade 2 extends in a plane (in an extension plane E) and is connected to a handle 3 extending in the extension of the blade 2, which handle 3 is, for example, substantially rectangular or optionally cylindrical. The handle 3 has a concave receiving portion for receiving a user's finger on the underside, as shown in FIGS. 1 and 2. The handle 3 can be formed as a single-piece handle. Alternatively, instead of a continuous handle 3, two handle half shells can be arranged on different sides of the blade 2, or the blade 2 can be sandwiched between these two handle half shells.

[0022] On the upper side or back of the grip 3, a mounting portion 4 is arranged on each side of the blade 2, and the orientation of the mounting portion 4 with respect to the extension plane E of the blade 2 is at an angle α, and the mounting portion 4 defines a mounting plane AE for allowing the cutting tool 1 to be stably placed on a flat underside U (e.g., a kitchen worktop, etc.) for sharpening or polishing the cutting edge 2b. The above-mentioned mounting portions 4 are arranged symmetrically on both sides of the cutting tool 1 with respect to the extension plane E of the blade 2, so that the cutting edge 2b can be sharpened symmetrically with respect to the extension plane E of the blade cutting portion 2a at an equal sharpening angle α.

[0023] In this embodiment, each of the mounting parts 4 is formed as a continuous surface of the back of the grip part 3. The mounting parts 4 meet at the back of the grip part 3 within the extension plane E of the blade cutting part 2a, forming an easy angle of 360°-2×α. Each of the mounting parts 4 does not have to be a continuous flat surface. It is also possible for a plurality of separate mounting parts 4 or mounting points 4a, 4b, 4c spaced apart from each other to be joined together to define the mounting plane AE. For example, two separate projections can be formed as the mounting parts 4 or mounting points 4a, 4b, 4c at the end of the front side (the tip 2d side) and the end of the rear side (the opposite side to the tip 2d) of the grip part 3 to define the mounting plane AE. This variant has the advantage that the handle 3, in particular the handle back, can be anatomically shaped for the user's regular use, without the user being tactilely aware of the rest 4 when holding the handle 3. In order to stabilize the cutting tool 1 in a regular processing position, it is useful for at least three different rest points 4a, 4b, 4c of each one of the rests 4 to be as far apart as possible from one another, in particular in the longitudinal direction L of the cutting tool 1 and in a direction perpendicular to the extension plane E of the blade 2a, so that the blade 2a can be held in engagement with the sharpening / polishing surface 5a at a constant working angle α during a regular sharpening / polishing process. In this example, the total length L of the kitchen knife 1 is about 30 cm. Here, ideally, the two rest points 4a, 4b of the rests 4 at the front and rear ends of the handle 3 are separated from one another by a distance X that corresponds to at least 30% of the length L. The distance X between the resting points 4a, 4b is preferably measured along the entire length of the cutting tool 1 and is shown in Fig. 2, where it is at least 9 cm. Such an arrangement prevents, for example, the blade back 2d from coming into contact with the underside U when the sharpening / grinding process of the cutting edge 2b is performed as specified. Ideally, when projected perpendicularly onto the resting plane AE defined by the resting part 4, the centre of gravity of the cutting tool 1 lies exactly within the area of ​​the resting part 4 or in the plane defined by the resting points 4a, 4b, 4c.

[0024] Furthermore, the distance Y between the resting point 4b and the extension plane E of the blade cutting portion 2a is at least 1% of the total length of the cutting tool 1 (here 30 cm or 300 mm), i.e. 3 mm, as shown in FIG. 3. The greater the distance Y between the outermost resting point 4b in the resting plane AE and the extension plane E of the blade cutting portion 2a, the less the inclination of the cutting tool 1 when in the processing position. This prevents the working angle α from being changed unintentionally during the regular sharpening / polishing process. Basically, it is desirable to increase the distance Y in order to improve the stability of the cutting tool 1 when in the regular processing position as shown in FIG. 4, but the dimension of the distance A should not be so large as to adversely affect the handling of the cutting tool 1 when cutting.

[0025] In FIG. 3, the cross-sectional profile of the cutting tool 1 of the present invention is symmetrical.

[0026] In the present embodiment, the angle α between the rest plane AE and the extension plane E of the blade cutting portion 2a is 70°. When the cutting tool 1 is rested on the flat underside U with the rest plane AE, this angle α corresponds to the so-called working angle α between the extension plane E of the blade cutting portion 2a and the flat underside U. This naturally positions the blade cutting portion 2a at the ideal sharpening angle β of 20° with respect to the sharpening surface 5a of the sharpening / polishing tool 5 mentioned at the beginning. As is known, when such a sharpening / polishing tool 5 is rolled on the underside U in the prescribed manner, the sharpening / polishing surface 5a of the sharpening / polishing tool 5 rotates in a plane oriented perpendicular to the underside U.

[0027] For proper use, the cutting tool 1 is first placed or pressed on the flat underside U on a placement plane AE so that the blade cutting portion 2a is disposed at a predetermined working angle α of 20° relative to the underside U (step A). ​​The above-mentioned 20° working angle α corresponds to the angle between the placement part 4 and the extension plane E of the blade cutting portion 2a. Preferably, the user applies a pressing force to the grip part 3, so that the force applied to the grip part 3 acts on the underside U directly via the placement part 4 arranged on the grip part 3, and the cutting tool 1 is stabilized in the processing position.

[0028] Next, the cutting edge 2b is placed against a grinding or polishing surface 5b oriented perpendicular to the underside U of the grinding or polishing tool 5 (Step B), and then the grinding or polishing surface 5b and the cutting edge 2b are moved relative to each other in the longitudinal direction of the cutting edge 2b to grind or polish the cutting edge 2b (Step C).

[0029] In order to sharpen both sides of the cutting edge 2b, the cutting tool 1 is placed on the lower part U in a placement plane AE defined by the other placement part 4. Then, the above steps (A to C) are repeated.

[0030] An example embodiment (not shown) is basically based on the above-mentioned embodiment, but has the same configuration except for the following differences, in which the position of the support 4 is adjustable to change the working angle α, and in some cases the position of the support 4 can be adjusted between a first position where the working angle is, for example, 70° and a second position where the working angle is, for example, 75°. Ideally, the support 4 can be locked in both the first and second positions to prevent undesired changes in the working angle α.

[0031] Other advantageous refinements of the invention are possible within the scope of protection of the claims.

[0032] The advantage of the invention is essentially that the cutting tool 1 according to the invention can be positioned at the appropriate sharpening angle β relative to the sharpening surface 5 without further auxiliary means. In particular, a knife 1 whose handle 3 has the inventive rest 4 can be tilted to the left or right and held at the appropriate sharpening angle β very simply and reliably without further auxiliary means. The handle 3 can be entirely flattened or it can be hollowed out in the longitudinal direction and only two sides are provided with rests or rest points. It is also possible to provide rounded and protruding rivets which serve as four-point rests. [Explanation of symbols]

[0033] 1. Cutting tools (knives) 2 Blades 2a Blade cutting edge 2b Cutting edge 2c Blade back 2d Blade Tip 3 Gripping part 4. Placement section 5 Sharpening and / or polishing equipment 5a Sharpening and / or polishing surfaces 5b Sharpening and / or polishing wheels 5c Grip AE mounting plane E (blade cutting edge) flat surface S Sharpening plane U bottom part

Claims

1. A cutting tool (1), in particular a knife, comprising at least one blade (2) having a blade cutting portion (2a) and a cutting edge (2b), The cutting tool (1) comprises at least one mounting portion (4), The mounting portion (4) defines a mounting plane (AE) on which the cutting tool (1) can be stably mounted on the flat lower surface portion (U) so that the blade cutting portion (2a) is oriented at a working angle (α) in the range of 65 to 80° with respect to the flat lower surface portion (U) in order to sharpen and / or polish the cutting edge (2b). A cutting tool (1).

2. The working angle (α) is in the range of 70 to 75°; A cutting tool (1) according to claim 1.

3. The grip portion (3) is provided. The gripping portion (3) has at least one placement portion (4), The placement portion (4) is preferably disposed on the opposite side of the grip portion (3) from the cutting edge (2b). A cutting tool (1) according to claim 1 or 2.

4. The placement portion (4) has at least three placement points (4a, 4b, 4c) located within the placement plane (AE) and not on a straight line, Preferably, at least 25%, 30% or 40% of the total length (L) of the cutting tool (1) is located between two of the placement points (4a, 4b, 4c), The total length (L) is preferably measured between the blade tip (2d) and the end of the gripping portion (3) opposite the blade tip (2d), Preferably, the distance (Y) between at least one of the placement points (4b) and the extension plane (E) of the blade cutting edge (2a) is greater than 1%, 2% or 3% of the total length (L) of the cutting tool (1); A cutting tool (1) according to any one of claims 1 to 3.

5. The blade cutting portion (2a) has two mounting portions (4) arranged on different sides thereof, Each of the mounting portions (4) defines a mounting plane (AE) on which the cutting tool (1) can be stably mounted on the flat lower surface portion (U) so that the orientation of the blade cutting portion (2a) relative to the flat lower surface portion (U) is the same working angle (α) in order to sharpen the cutting edge (2b). A cutting tool (1) according to any one of claims 1 to 4.

6. The placement portion (4) is arranged in the cutting tool (1) so as to be positionably adjustable. A cutting tool (1) according to any one of claims 1 to 5.

7. the mounting portion (4) is adjustable between at least two different positions to vary the working angle (α); Preferably, the working angle (α) is 70° when the mounting portion (4) is in the first position, and the working angle (α) is 75° when the mounting portion (4) is in the second position. A cutting tool (1) according to claim 6.

8. A set comprising a cutting tool (1) according to any one of claims 1 to 7 and a sharpening and / or polishing tool (5), The sharpening and / or polishing tool (5) has at least one sharpening and / or polishing surface (5b) that rotates in a plane (S) oriented perpendicular to the flat lower surface (U) as the sharpening and / or polishing tool (5) rolls on the lower surface (U). A set characterized by:

9. The sharpening and / or polishing tool (5) has a cylindrical gripping body (5c), The sharpening and / or polishing surfaces (5b) are arranged at each axial end of the gripping body (5c); The set according to claim 8.

10. A method for sharpening and / or polishing a cutting tool (1) according to any one of claims 1 to 7, comprising the steps of: a. placing the cutting tool (1) on the flat underside (U) in the placement plane (AE) such that the blade cutting edge (2a) is at a working angle (α) in the range of 65-80° with respect to the flat underside (U); b. placing said cutting edge (2b) against a sharpening and / or polishing surface (5b) of a sharpening and / or polishing tool (5) oriented perpendicular to said lower surface (U); c. sharpening and / or polishing said cutting edge (2b) by moving said sharpening and / or polishing surface (5b) relative to said cutting edge (2b) (in the longitudinal direction of said cutting edge (2b)); The method according to claim 1, further comprising:

Images