Cutting tool with support section for pre- grinding angle

Abstract

The invention relates to a cutting tool (1), in particular a tool, comprising at least one tool body (2) with a blade (2a) and a cutting edge (2b). In order to enable a precise grinding or polishing of the cutting tool (1) even without a grinding jig, it is provided according to the invention that the cutting tool (1) has at least one bearing section (4) which defines a bearing plane (AE), on which the cutting tool (1) can be stably placed against a planar base (U) for grinding and / or polishing the cutting edge (2b) such that the blade (2a) is oriented at a working angle (a) in the range of 65 to 80° to the base (U). Also disclosed is a kit for grinding and / or polishing a cutting tool (1) and a corresponding method.

Description

TECHNICAL FIELD

[0001] The invention relates to a cutting tool, in particular a knife, for example a kitchen knife, comprising at least one blade with a blade and a cutting edge. BACKGROUND

[0002] For grinding or polishing the cutting edge, a grinding or polishing tool with a rotating grinding or polishing surface can be used. Such a grinding or polishing tool, also known as a "roll grinder", is known, for example, from DE 20 2020 001 180 U1 or EP 3 278 928 A.

[0003] For positioning the blade relative to the grinding or polishing tool, a so-called grinding jig can be used. With this grinding jig, the blade is positioned relative to the grinding surface at a predetermined grinding angle in order to grind the cutting edge at the predetermined grinding angle by the grinding jig.

[0004] In order to achieve a satisfactory processing result, three components are indispensable and must act together, namely the cutting tool, the grinding jig and the grinding / polishing tool. Thereby, for the user, the logistical and coordination effort for the grinding or polishing processing of the cutting tool is increased. SUMMARY

[0005] To solve this problem, the invention provides a cutting tool according to claim 1, a kit according to claim 8 and a method according to claim 10.

[0006] The cutting tool according to the invention is in particular a knife or kitchen knife comprising at least one blade with a blade and a cutting edge, wherein the cutting tool has at least one bearing section which determines a bearing plane, said cutting tool being able to rest stably on a planar base with the bearing plane for grinding and / or polishing the cutting edge, such that the blade (or its extension plane) is oriented at a working angle in the range of 65 to 80° to the base. The working angle denotes the angle between the blade (or its extension plane) and the bearing plane. The working angle denotes the angle between the blade (or its extension plane) and the base when the bearing plane is resting on the base. The grinding angle denotes the angle between the extension plane of the blade and the grinding surface. In the roll grinder mentioned at the outset, the grinding surface rotates in a plane which is oriented perpendicular to the base. Thus, the grinding angle β is calculated from the working angle a by formula I:

[0007] Formula I: β = 90° - a.

[0008] "stable" in the context of the present application means that the cutting tool rests on the base with the support plane even during grinding or polishing machining while maintaining the working angle. Here, the cutting tool is preferably held by the user on the handle and pressed with the support plane against the base. Ideally, but not necessarily, the cutting tool can be stably rested on the base with the support section autonomously, that is to say without external force. When the cutting tool is rested on the base with the support section, the center of gravity of the cutting tool preferably lies in the projection of the cutting tool on the base in the area of the support section (between the support points). However, in order to exert a counterforce on the forces exerted by the grinding / polishing tool on the blade during grinding or polishing machining, it has proven advantageous if the cutting tool is held by the user and pressed with the support section against the base during grinding or polishing machining. During grinding or polishing machining, the cutting edge of the blade preferably faces away from the base and the back of the blade faces the base (see Figure 4 ). However, it is also possible in principle for the support section to be arranged on the cutting tool such that the cutting edge of the blade faces the base during grinding or polishing machining and the back of the blade faces away from the base. The working angle can be determined in the range from 65 to 80° when manufacturing the cutting tool or, if necessary, by adjusting the support section before the start of grinding or polishing machining. The working angle is preferably constant during grinding or polishing machining in order to grind the cutting edge uniformly and sharpen it.

[0009] An advantageous development of the present application is the content of the dependent claims.

[0010] It can be advantageous if the working angle is in the range from 70 to 75°. In practice, a grinding angle of 15° or 20° has proven to be particularly advantageous. A grinding angle of 15° is used for grinding very sharp blades, for example the blades of a slicing knife for cutting meat. In the case of a grinding angle of 20°, the cutting edge is less sharp, but is less prone to wear. Depending on the choice of the grinding angle in the range from 15 to 20° (corresponding to a working angle of 70 to 75°), the sharpness and the wear properties of the cutting edge can be adjusted.

[0011] It can prove advantageous if the cutting tool has a handle body, wherein the handle body preferably has at least one support section, wherein the support section is preferably arranged on the side of the handle which faces away from the cutting edge (for example on the back of the handle). In particular during grinding or polishing machining, a pressing force can be exerted on the handle body in order to press the cutting tool resting on the base with the support plane in the machining position against the base. In this way, the adhesive friction between the cutting tool and the base can be improved.

[0012] It can be advantageous if the support section has at least three support points in the support plane, which are not located on a line, wherein preferably at least 25%, 30% or 40% of the total length of the cutting tool, measured between the blade tip and the end of the handle body remote from the blade tip, is located between two of the support points, wherein preferably at least one of the support points has a distance from the extension plane of the blade which is greater than 1%, 2% or 3% of the total length of the cutting tool. The dimensions of the support section are not decisive for the stability of the arrangement, but rather the distance in the support plane between the support points, in particular perpendicular to the extension plane of the blade, is decisive. Although the relative movement between the cutting edge and the grinding / polishing tool usually takes place in or parallel to the extension plane of the blade body, there are usually still forces during grinding or polishing machining which act transversely to the extension plane of the blade body and press the blade body and the cutting tool out of the normal machining position. A large contact surface between the cutting tool and the base increases the adhesive friction between the cutting tool and the base and stabilizes the cutting tool in the machining position. It can be advantageous if the support section is configured to be resilient, in particular as a silicone coating. Thereby, the adhesive friction between the cutting tool and the base can be further improved.

[0013] It can prove to be suitable if the cutting tool has two such support sections, which are arranged on different sides of the blade (extension plane) and each determine a support plane on which the cutting tool can be stably placed against a planar base for grinding the cutting edge, such that the blade (or its extension plane) is each oriented with the same working angle to the base. In this way, both sides of the cutting edge can be ground or polished particularly uniformly.

[0014] It can be practical if the support section is adjustably arranged on the cutting tool. Thereby, the cutting edge can be ground or polished with a specific grinding angle depending on the use case.

[0015] It can prove to be advantageous if the support section can be adjusted between at least two different positions in order to change the working angle, wherein preferably the working angle is 70° in a first position of the support section and 75° in a second position of the support section. Thus, the grinding angle is 20° in the first position and 15° in the second position.

[0016] A further aspect of the application relates to a kit comprising a cutting tool according to one of the preceding embodiments and a grinding and / or polishing tool having at least one grinding and / or polishing face which rotates in a plane oriented perpendicular to the base when the grinding and / or polishing tool is rolled.

[0017] If the grinding and / or polishing tool has a cylindrical handle body, it can be advantageous if such a grinding and / or polishing face is arranged at each axial end of the handle body. These design forms of the grinding / polishing tool prove to be versatile and in practice prove to be particularly effective.

[0018] A further aspect of the present application relates to a method for grinding and / or polishing a cutting tool according to one of the preceding embodiments, wherein the method comprises the following steps:

[0019] - Step A: Arranging the cutting tool with the support plane on a planar base so that the blade is arranged at a working angle in the range of 65 to 80 degrees to the base. Here, the cutting tool is preferably pressed with force by the user with the support section against the base, so that the blade is distanced from the base.

[0020] - Step B: Resting the blade against a grinding and / or polishing face of a grinding and / or polishing tool which is oriented perpendicular to the base. A roll grinder known, for example, from EP 3 278 928 A has a (cylinder with two lateral faces) grinding or polishing face which rotates in a plane oriented perpendicular to the base when the roll grinder rolls on a planar base.

[0021] - Step C: Grinding and / or polishing the blade by carrying out a relative movement between the grinding and / or polishing face and the blade. Here, it is preferred that the cutting tool remains positionally fixed relative to the base, while the grinding / polishing tool is moved along the blade when rolling on the base in the longitudinal direction of the blade. By means of the slight contact pressure between the cutting tool and the grinding / polishing tool, the grinding or polishing face grinds the material of the blade body during the relative movement, so that the blade is ground or polished.

[0022] Further advantageous developments of the present application are obtained by the combination of the features disclosed in the description, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0023] The drawings show:

[0024] Figure 1 is a schematic side view of a cutting tool according to the present application, in the form of a kitchen knife, with a blade body, a handle body and a support section arranged on the handle body which determines a support plane for supporting the cutting tool on a planar base;

[0025] Figure 2 is Figure 1 a schematic side view of the cutting tool shown from the other side;

[0026] Figure 3 is a sectional view along the sectioning plane A-A in Figure 1 ;

[0027] Figure 4 is a schematic front view of the cutting tool from the perspective of the blade tip, wherein the cutting tool is conventionally resting with one of the support surfaces on a planar base such that the blade is oriented with the base at a predetermined working angle, wherein the cutting edge of the blade is machined using a grinding and / or polishing tool. DETAILED DESCRIPTION

[0028] A preferred embodiment of the present application is explained in detail below with reference to the accompanying drawings.

[0029] Figure 1 A side view of the cutting tool 1 of the present application is shown, which is configured as a kitchen knife. The kitchen knife 1 comprises a flat, elongated blade body 2 having a blade 2a, a convexly curved lower side cutting edge 2b, a straight upper side blade back 2c and a front tip 2d. The blade body 2 extends in a plane of extension E and is connected with a handle 3, for example approximately cuboid or as an alternative cylindrical, which extends along the line of extension of the blade body 2. As shown in Figure 1 and 2 The handle 3 has a concave recess on the lower side for the fingers of the user. The handle 3 can be configured as a one-piece handle body. As a further alternative, it is also possible to provide two handle half-shells on different sides of the blade body 2 instead of one complete handle body 3, or the blade body 2 is arranged sandwich-like between the two handle half-shells.

[0030] On the upper side or back of the handle 3, there is a support section 4 on each side of the blade body 2, which is oriented at an angle a to the plane of extension E of the blade body 2 and determines a support plane AE, in order to be able to rest the cutting tool 1 stably on a planar base U, for example a kitchen worktop, in order to grind or polish the cutting edge 2b. The support sections 4 are arranged symmetrically on both sides of the cutting tool 1 with respect to the plane of extension E of the blade 2a, so that the cutting edge 2b can be ground symmetrically with respect to the plane of extension E of the blade 2a at the same grinding angle β.

[0031] In the present embodiment, each bearing segment 4 is configured as a continuous plane on the back of the handle 3. The two bearing segments 4 converge in the extension plane E of the blade 2a at the spine of the handle 3 and form an overblunt angle of 360° - 2*α. It is not necessary for each bearing segment 4 to be configured as a continuous plane itself. It is also possible for a plurality of separate and mutually spaced bearing segments 4 or bearing points 4a, 4b, 4c to jointly determine the bearing plane AE. In this way, for example, two mutually spaced projections as bearing segments 4 or bearing points 4a, 4b, 4c can be configured at the (tip 2d-facing) front end and the (away from the tip 2d) rear end of the handle 3 to determine the bearing plane AE. The advantage of this variant is that, for the user's normal use, the handle 3, in particular at the handle back, can be shaped ergonomically, without the user having to perceive the bearing segments 4 when holding the handle 3. When at least three different bearing points 4a, 4b, 4c of each bearing segment 4 are spaced as far apart from one another as possible, in particular along the longitudinal direction L of the cutting tool 1 and perpendicular to the extension plane E of the blade 2a, the blade 2a is able to engage with the grinding / polishing surface 5a at a constant working angle α during normal grinding / polishing machining, which contributes to the stability of the cutting tool 1 in the normal machining position. In the present example, the kitchen knife 1 has a total length L of approximately 30 cm. In this case, the two bearing points 4a, 4b of the bearing segments 4 on the front end and the rear end of the handle 3 are ideally spaced apart from one another by a distance X that corresponds to at least 30% of the length L. In the present example, the distance X is ideally at least 9 cm. In this way, for example, it is possible to prevent the knife back 2d from coming into contact with the base U during normal grinding / polishing machining of the blade 2b. Ideally, the centre of gravity of the cutting tool 1 in the projection onto the bearing plane AE determined by the bearing segments 4 lies exactly in the region of the bearing segments 4 or in the plane determined by the bearing points 4a, 4b, 4c. Figure 2 The distance X between the bearing points 4a and 4b is shown in Figure 2 , which is preferably measured along the total length of the cutting tool 1 and is therefore at least 9 cm. In this way, for example, it is possible to prevent the knife back 2d from coming into contact with the base U during normal grinding / polishing machining of the blade 2b. Ideally, the centre of gravity of the cutting tool 1 in the projection onto the bearing plane AE determined by the bearing segments 4 lies exactly in the region of the bearing segments 4 or in the plane determined by the bearing points 4a, 4b, 4c.

[0032] In addition, as shown in Figure 3 , the bearing point 4b has a distance Y from the extension plane E of the blade 2a, which is at least 1% of the total length of the cutting tool 1, here 30 cm or 300 mm, that is to say 3 mm. The greater the distance Y of the outermost bearing point 4b in the bearing plane AE from the extension plane E of the blade 2a, the less the cutting tool 1 will tilt in the machining position. In this way, it is possible to prevent the working angle α from changing unintentionally during normal grinding / polishing machining. In principle, a greater distance Y is ideal for improving the stability of the cutting tool 1 in the normal machining position, as shown in Figure 4 , however the distance Y should not be so great that it adversely affects the handling of the cutting tool 1 in the cutting.

[0033] In the view according to Figure 3 The cutting tool 1 of the application has a symmetrical cross-sectional profile.

[0034] In the present embodiment, the angle a between the bearing plane AE and the extension plane E of the blade 2a is 70°. This angle a corresponds to the so-called working angle a between the extension plane E of the blade 2a and the planar base U when the cutting tool 1 is resting with the bearing plane AE against the planar base U. Thereby, the blade 2a is automatically positioned in the desired grinding angle β of 20° with respect to the grinding face 5a of the grinding / polishing tool 5 mentioned at the outset. When the tool 5 is conventionally rolled over the base U, the grinding / polishing face 5a of such a grinding / polishing tool 5 rotates in a plane oriented perpendicularly to the base U in a well-known manner.

[0035] For conventional use, the cutting tool 1 is first rested or pressed with the bearing plane AE against the planar base U such that the blade 2a is arranged in the predetermined working angle a of 20° with respect to the base U (step A), which working angle corresponds to the angle between the bearing section 4 and the extension plane E of the blade 2a. The user preferably exerts a pressure on the handle 3 such that the force introduced into the handle 3 acts directly on the base U via the bearing section 4 arranged on the handle 3 and stabilizes the cutting tool 1 in the machining position.

[0036] Subsequently, the cutting edge 2b is brought to bear against the grinding or polishing face 5b of the grinding or polishing tool 5 oriented perpendicularly to the base U (step B) and is then ground or polished by performing a relative movement between the grinding or polishing face 5b and the cutting edge 2b along the longitudinal direction of the cutting edge 2b (step C).

[0037] For grinding both sides of the cutting edge 2b, the cutting tool 1 is rested on the base U with the bearing plane AE determined by the other bearing section 4. Then, the above-described steps (A to C) are repeated.

[0038] In an embodiment not shown, which has the same features as the aforementioned embodiment except for the following differences, the bearing section 4 is adjustable for varying the working angle a and can be adjusted, if necessary, between a first position in which the working angle is, for example, 70° and a second position in which the working angle is, for example, 75°. Ideally, the bearing section 4 can be locked both in the first position and in the second position, thereby preventing an unintended change in the working angle a.

[0039] Further advantageous developments of the application are possible within the scope of protection of the claims.

[0040] The advantage of the present invention is essentially that the cutting tool 1 of the present invention can be positioned with the respective grinding angle β against the grinding surface 5 without additional auxiliary tools. In particular, the tool 1 with the shank 3 having the support section 4 of the present invention can be tilted to the left and / or to the right without additional auxiliary tools, very easily and reliably, in the respective grinding angle β. The entire shank can be ground flat. However, the shank 3 can also be ground hollow in the longitudinal direction, in order to have a support or supports only on two edges. Even round, convex rivets are conceivable, which constitute a four-point support.

[0041] List of reference signs

[0042] 1 cutting tool (tool)

[0043] 2 blade

[0044] 2a insert

[0045] 2b cutting edge

[0046] 2c back

[0047] 2d tip

[0048] 3 shank

[0049] 4 support section

[0050] 5 grinding and / or polishing tool

[0051] 5a grinding and / or polishing surface

[0052] 5b grinding and / or polishing wheel

[0053] 5c shank body

[0054] AE support plane

[0055] E plane (of the insert)

[0056] S grinding plane

[0057] U base

Claims

1. A cutting tool (1) comprising: At least one blade (2a) and a cutting edge (2b), wherein the cutting tool (1) has at least one bearing section (4) which defines a bearing plane (AE), on which the cutting tool (1) can be stably placed on a planar base (U) for grinding and / or polishing the cutting edge (2b) so that the blade (2a) is oriented at a working angle (a) in the range of 65 to 80° to the base (U).

2. The cutting tool (1) according to the preceding claim, characterized in that The working angle (a) is in the range of 70 to 75°.

3. The cutting tool (1) according to claim 1 or 2, characterized in that The cutting tool (1) has a handle (3), wherein the handle (3) has at least one of the bearing sections (4), wherein the bearing section (4) is arranged on the side of the handle (3) which is remote from the cutting edge (2b).

4. The cutting tool (1) according to claim 1 or 2, characterized in that The bearing section (4) has at least three bearing points (4a, 4b, 4c) in the bearing plane (AE), which are not located on a line, wherein at least 25%, 30% or 40% of the overall length (L) of the cutting tool (1) measured between the blade tip (2d) and the end of the handle (3) remote from the blade tip is located between two of the bearing points (4a, 4b), wherein at least one of the bearing points (4b) has a distance (Y) to the extension plane (E) of the blade (2a) which is greater than 1%, 2% or 3% of the overall length (L) of the cutting tool (1).

5. The cutting tool (1) according to claim 1 or 2, characterized in that The cutting tool (1) has two bearing sections (4) which are arranged on different sides of the blade (2a) and each define a bearing plane (AE), on which the cutting tool (1) can be stably placed on a planar base (U) for grinding the cutting edge (2b) so that the blade (2a) is oriented at the same working angle (a) to the base (U), respectively.

6. The cutting tool (1) according to claim 1 or 2, characterized in that The bearing sections (4) are adjustably arranged on the cutting tool (1).

7. The cutting tool (1) according to claim 1 or 2, characterized in that The bearing sections (4) are adjustable between at least two different positions in order to change the working angle (a), wherein the working angle (a) is 70° in a first position of the bearing section (4) and 75° in a second position of the bearing section (4).

8. Kit comprising a cutting tool (1) according to any one of the preceding claims and a grinding and / or polishing tool (5) having at least one grinding and / or polishing surface (5b) which rotates in a plane (S) oriented perpendicular to the base (U) when the grinding and / or polishing tool (5) is rolled on a planar base (U).

9. Kit according to the preceding claim, characterized in that, The grinding and / or polishing tool (5) has a cylindrical handle body (5c), wherein on each axial end of the handle body (5c) such a grinding and / or polishing surface (5b) is arranged.

10. Method for grinding and / or polishing a cutting tool (1) according to any one of the preceding claims, characterized in that, The method comprises the following steps: a. Arranging the cutting tool (1) with the bearing plane (AE) on a planar base (U) so that the blade (2a) is arranged at a working angle (a) in the range of 65 to 80° to the base (U), b. abutting the blade (2b) against a grinding and / or polishing face (5b) of the grinding and / or polishing tool (5) oriented perpendicular to the base (U), c. grinding and / or polishing the blade (2b) by performing a relative movement between the grinding and / or polishing face (5b) and the blade (2b) (in the longitudinal direction of the blade (2b)).

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