Roller sharpener comprising a multi-part, hollow body

Abstract

The present invention relates to a roller sharpener (3) for sharpening and / or polishing a cutting edge (2a) of a cutting tool (2), preferably of a household knife, wherein the roller sharpener (3) consists substantially of two running rollers (4), a body (5) to be rotatably arranged between the rollers (4) and relative thereto, and a shaft (6) to be rotatably mounted in the body (5), and one or both of the running rollers (2) has / have a sharpening or polishing surface (4a) arranged thereon. The aim of the invention is to provide a weight-reducing magnetic sharpening jig (1). According to the invention, this is achieved in that the roller sharpener (3) has a body (5) which consists of two assembled components (9, 10) and is hollow at least in some sections.

Description

[0001] Roller grinder with multi-part, hollow body

[0002] The present invention relates to a roller grinder, in particular for grinding a cutting tool to be ground or polished.

[0003] A generic roller grinder according to the preamble of claim 1 is known from EP 3 278 928 A1 or DE 10 2020 123 501 A1

[0004] The roller grinder known from the prior art has a body for gripping the roller grinder, which is made of wood, plastic, or metal, for example. The body is solid and thus extremely stable, ensuring a secure grip of the roller grinder even when high forces are applied to the blade during grinding or polishing. While such one-piece components have the advantage of being easy to manufacture, they require a high level of raw materials and thus result in high production costs. Furthermore, the solid construction of the body required for stability is accompanied by a high weight. This increases the transport costs for the raw materials and for delivery per manufactured product.

[0005] The present invention is therefore based on the object of providing a roller grinder with low weight and high stability that is resource-efficient and easy to manufacture.

[0006] To achieve this object, the present invention provides the roller grinder according to claim 1. The roller grinder according to the invention is used in particular for grinding a cutting tool with a magnetizable blade that is to be ground or polished. The roller grinder comprises a body and at least one grinding or polishing wheel that is rotatable relative to the body. According to the invention, the roller grinder has a body that consists of two assembled components and is hollow at least in sections.

[0007] The key advantage of the present invention over the prior art is that a hollow body can be manufactured from the assembled components with little effort. Due to the multi-part design of the body, a cavity in the center of the body can be easily created by bringing the components together, without having to avoid undercuts during production. The weight of a body that is at least partially hollow is significantly lower than that of a magnetic grinding gauge body, which is made from a single piece and solid wood, plastic, or metal. The hollow body thus serves to save weight and increase resource efficiency, since fewer raw materials are required to manufacture the body.

[0008] It can be advantageous if at least two components are made of plastic, preferably by injection molding. Plastic is a cost-effective material with excellent stability and processing properties. Injection molding has the advantage that complex component structures can be manufactured quickly and cost-effectively in large quantities.

[0009] It can prove useful if one of the components forms a housing component with a receptacle, preferably in the axial direction, into which the other component is inserted as an insert component. This supports intuitive assembly of the components and minimizes the number of joints on the outer contour of the body. The body is thus protected from dirt and liquids that could penetrate the body. The axially arranged receptacle ensures that when the insert component is inserted independently into the housing component, a shell surface of the body remains free of steps, draft angles, or distortions.

[0010] It can be beneficial if the housing component encloses the insert component in such a way that a bottom surface of the insert component and an edge of the housing component are flush in a frontal plane. The flushness of the bottom surface and the edge of the components indicates correct assembly of the components and ensures a flat frontal plane of the body, which rotates stably on the axis between the rollers.

[0011] It can prove helpful if the two components are cylindrical or cup-shaped, with one component being inserted coaxially into the other in an assembled state, preferably with the base sections of the components facing each other. Due to their circular cross-sections, the shape of the cylinder or cup exhibits a very high structural capacity against compression and torsion. Closed cross-sections, such as those of cylindrical components, have a high torsional resistance. This is particularly suitable for the grip of the rolling element.

[0012] It can be advantageous if the two components have a distinguishable framework structure, at least in sections, particularly in a star, honeycomb, rib, or lattice structure. The different framework structures of the components in star, honeycomb, rib, or lattice form enable individual design of the components for an optimum balance between lightweight construction and stability. It can be useful if rib and groove structures and / or a shoulder are formed on the contact surfaces of the components that are inserted into one another, which serve as an engagement structure. The ribs and grooves ensure that the components are assembled correctly and that they are protected against rotation when assembled.

[0013] It can be useful to have a circumferential shoulder on the contact surfaces of the nested components on the front side of the body, where the components are preferably welded together, even more preferably ultrasonically welded. The shoulder ensures a precise fit of the components. By welding the components at the shoulder, the components can be easily and reliably connected to one another. Welding connects the components and seals the contact surface. The body is thus protected from dirt and liquids that could penetrate the body.

[0014] It can be advantageous if the rotational axis of the body, the rotational axis of the rollers, and the rotational axis of the axle coincide. This results in a concentric position of the components relative to each other and enables a constant rolling motion of the body with the rollers. This ensures comfortable operation for the user.

[0015] It may prove advantageous if the roller grinder has two rollers between which the body is arranged, with the body and the rollers having exactly or substantially identical outer diameters, preferably such that a peripheral surface of the body and a peripheral surface of the rollers are arranged flush with one another. This design has an attractive aesthetic appearance and reduces the risk of injury to a user because there are only small gaps between the rotating parts and no rotating parts protrude. Ideally, the peripheral surfaces of the body and the rollers are exactly or substantially cylindrical.

[0016] It can be useful if the rollers each have a circumferential rubber ring, which is preferably arranged in at least one groove on the outer circumference of the rollers, wherein the rubber ring preferably has the largest diameter with respect to an axis of the roller grinder, so that the rubber ring rolls on the base when the roller grinder is moved over the base. Due to its elastic properties, the rubber ring can ensure that the rollers roll on the base without slipping. Optionally, the ring can be reversibly transferred from the groove on the outer circumference of the roller into a groove on the outer circumference of the roller, so that when the device is moved over a base by exerting force on the handle, the rollers - rotating relative to the handle - roll on the base and the roller grinder is thereby set in rotation.Preferably, the ring is arranged optionally in one of several grooves on the outer circumference of the roller, wherein the grooves have different diameters, wherein the ring in each of these grooves has the largest diameter with respect to an axis of the device (of all components of the device), so that the ring rolls on the base when the device is moved over the base. The different diameters make it particularly easy to change the rolling circumference of the roller. In order to be able to arrange it in the different grooves on the outer circumference of the roller, a particularly elastic ring is recommended, e.g. made of rubber, which can be stretched accordingly and adapts to the corresponding outer diameter of the grooves.

[0017] A further aspect of the invention relates to a set comprising a roller grinder according to one of the preceding embodiments and a magnetic grinding gauge, preferably a magnetic grinding gauge according to EP 4 210 901 A. Such a magnetic grinding gauge holds the cutting tool to be ground by means of magnetic force and positions it relative to the roller grinder.

[0018] Further advantageous embodiments result from combinations of the features disclosed in the claims, the description and the drawings.

[0019] Short description of the characters

[0020] They show:

[0021] Fig. 1 : a schematic view of an arrangement comprising a magnetic grinding gauge, a cutting tool to be ground or polished and a grinding and / or polishing tool in the form of a roller grinder, wherein the blade of the cutting tool is held in contact with the magnetic grinding gauge so that the back of the blade is at a distance from the substrate and the cutting edge of the cutting tool is directed away from the substrate.

[0022] Fig. 2: the arrangement according to Fig. 1 from a different perspective.

[0023] Fig. 3: an exploded perspective view of a roller grinder.

[0024] Fig. 4A: A first perspective view of a housing component and an insert component of a body in a state prior to assembly into the body. Fig. 4B: A second perspective view of the housing component and the insert component of the body from Fig. 4A.

[0025] Fig. 5: a sectional view of the assembled body.

[0026] Fig. 6: a sectional view of the assembled body installed in a roller grinder.

[0027] Detailed description of the preferred embodiments

[0028] A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0029] A roller grinder 3 is a grinding device that can be moved in a rolling manner over a base U, so that a front-end grinding and / or polishing wheel 4 is rotated in order to grind the cutting edge 2a of a cutting tool 2 held against the wheel 4. The roller grinder 3 according to the invention serves to grind the cutting tool 2 to be ground or polished, having a magnetizable blade 2a, which is held, for example, by a magnetic grinding gauge 1 by means of magnetic force. According to the invention, the roller grinder 3 comprises a body 5 that consists of two assembled components 9, 10 and is hollow at least in sections. The roller grinder 3 is stressed independently of the cutting tool 2 and its blade 2a.

[0030] The magnetic grinding gauge 1 is designed in particular for positioning cutting tools 2 in the form of kitchen knives. Kitchen knives often have a stainless steel blade 2a with an approximately flat blade surface and a slightly curved, one-sided cutting edge 2b. However, it is fundamentally possible that, in addition to kitchen knives, other cutting tools 2 can also be positioned with the magnetic grinding gauge 1 according to the invention. The shape of the cutting tool 2 and the blade 2a are therefore not critical.

[0031] Figures 1 and 2 show the general composition and use of the magnetic grinding gauge 1, the cutting tool 2 to be ground or polished, and the roller grinder 3. To grind or polish a cutting tool 2 with the magnetic grinding gauge 1, the magnetic grinding gauge 1 is placed on a flat base U. A cutting tool 2 provided with a magnetizable blade 2a and cutting edge 2b, such as a kitchen knife with a stainless steel blade, is arranged with its magnetizable blade 2a in the magnetic field of the magnetic grinding gauge 1 as intended, so that the blade is aligned parallel to the contact surface of the contact element and only the magnetically attracted blade 2a comes into (full) contact with the contact element. The cutting edge 2b points away from the base U and the blade 2a is spaced from the base U.The blade 2a is therefore held in contact with the contact element 4 solely by the magnetic force of the magnetic grinding gauge 1.

[0032] The roller grinder 3 with body 5 is movable in a rolling manner over a base and has at least one frontal grinding or polishing surface. The roller grinder 3 with the frontal grinding or polishing surface is moved in a horizontal rolling manner over the flat base U and is held with the grinding or polishing surface aligned in a vertical plane in contact with the cutting edge 2b of the blade 2a of the cutting tool 2. The direction of movement of the roller grinder is approximately parallel to the direction of extension of the blade 2a. The grinding angle is defined by the plane of extension of the blade 2a, which is held in contact with the contact element as intended, and the vertical plane of the grinding or polishing surface. The body 5 serves as a handle for handling the device according to the invention or the roller grinder 3. The body 5 is therefore suitable for being held in the hand of a user while the roller grinder 3 moves over a base U, i.e.pushed or pulled.

[0033] Fig. 3 shows an exploded view of a conventional roller grinder 3. The body 3 is a cylinder that extends along a central axis X5 and has a cylindrical outer surface 5a, two parallel end faces 5b, and a cylindrical central bore 5c of uniform diameter. To fix the rolling bearings 12 described below, a bearing sleeve 11 is inserted into the central bore 5a from each end face 5a of the body 3, which is supported by a flange on the end face 5a of the body 3. The bottom of the bearing sleeve 11 is provided with an opening for the passage of the axle 6. Outside the body 5, rollers 4 are arranged on the axle 6, with the axle 6 extending through bearing bores 4b of the rollers 4.The outer diameter of the body 5 preferably corresponds to the outer diameter of the rollers 4, so that the outer surface 5a of the body 5 and the outer surfaces of the rollers 4 merge flush with one another in the intended assembly state. The axle 6 is designed as a stepped axle 6 with a central section 6a and stepped bearing sections 6b at the ends.

[0034] The rolling bearing 12 is, for example, a standard ball bearing. The inner diameter of the inner ring of the rolling bearing 12 is matched to the outer diameter of the bearing section 6b of the axle 6 and can be mounted on it, so that the inner ring is supported axially on the central section 6a of the axle 6. The outer diameter and axial length of the rolling bearing 12 are matched to the dimensions of the body 5. The rolling bearing 12 can therefore be precisely inserted into the central bore or bearing sleeve of the body 5 and can be supported axially with the outer ring on the bearing support section.

[0035] A bearing sleeve 11 is, for example, an annular disc or cylindrical sleeve that can be pushed onto the bearing section 6b of the axle 6 to bear against the inner ring of the rolling bearing 12 and a roller 4. Various types of bearing sleeves 11 are provided, each having a different axial length, in order to precisely adjust the distance between the rollers 4 to be attached to the axle 6, depending on the actual dimensions of the body 5—and thus the gap between each roller 4 and the body 5.

[0036] In the assembled state, the central axes X6 of the axis 6 as well as the rotation axis X4 of the connected roller 4 and the rotation axis X5 of the body 5 coincide on a common central or rotation axis.

[0037] The preferred embodiment of the roller grinder 3 according to the invention is explained below with reference to the figures (Figures 4A to 6).

[0038] The rolling body 3 according to the invention comprises a multi-part, at least partially hollow body 5. The body consists of at least two components 9, 10. The components 9, 10 are made of plastic, preferably recycled plastic, and are preferably manufactured by injection molding. This allows complex component structures to be manufactured quickly and in one piece. 3D printing is also conceivable as a manufacturing method for the components 9, 10.

[0039] 4A and 4B each show a perspective view of two components 9, 10 of a body 5 in a state prior to assembly to form the body 5 from both directions of the rotation axis X5. The components 9, 10 are each cylindrical. The component 9 with the larger diameter shown in Figures 4A and 4B is a housing component 9. The component 10 with the smaller diameter shown in Figures 4A and 4B is an insert component 10. The housing component 9 is cup-shaped and has a receptacle 9a in the axial direction. The insert component 10 can also be cup-shaped. The cup-shaped components 9, 10 each have a base section 9b, 10b. In a state before the assembly of the components 9, 10, the bottom sections 9b, 10b are arranged such that the bottom sections 9b, 10b are opposite one another.During assembly, the insert component 10 is inserted coaxially into the housing component 9 so that the base sections 9b, 10b structurally close off the body 5 at the front.

[0040] The two components 9, 10 have a framework structure 9d, 10d at least in sections, preferably in the base sections 9b, 10b. In the present embodiment, the framework structure 9d, 10d is designed as a star structure, but can also be formed as a honeycomb, rib, or lattice structure. The framework structure 9d, 10d enables individual design of the components 9, 10 for an optimum balance between lightweight construction and stability of the components 9, 10. The less framework structure 9d, 10d required, the greater the proportion of hollow space in the components 9, 10, which reduces the weight of the components 9, 10.

[0041] The outer surfaces of the two components 9, 10 become contact surfaces 8 in the assembled state. The contact surfaces 8 of the components 9, 10 each have rib or groove structures 9e, 10e. Arranged on the outer surface of the insert component 10 are a plurality of ribs 10e which are configured to be inserted into grooves 9e on the inner outer surface of the housing component 9. The rib or groove structures 9e, 10e serve as an engagement structure. By guiding them during assembly, the ribs and grooves ensure flawless assembly of the components 9, 10 and prevent rotation in the assembled state. It is conceivable that the grooves and ribs generate a force-locking press fit between the components 9, 10. It is also conceivable that contact surfaces 8 do not have grooves and ribs, but are flat and generate a press fit, which in the assembled state generates a firm fit of the components 9, 10 to one another.

[0042] The housing component 9 has an edge side 9c on the outer edge of the receptacle 9a. The edge side 9c is stepped radially inward toward the inner surface of the housing component 9 by a shoulder 13. The insert component 10 has a bottom surface 10c on the outer edge of the bottom section 10a. The bottom surface 9c is stepped radially outward toward the lateral surface of the insert component 10 by a shoulder 14.

[0043] Fig. 5 shows a sectional view of the assembled body 5 in which the insert component 10 is inserted into the housing component 9. In the assembled state, the shoulders 13 and 14 flange together so that the housing component 9 encloses the insert component 10 such that the bottom surface 10c of the insert component 10 and the edge side 9c of the housing component 9 lie flush in a front plane S of the body 5. The flushness of the edge side 9c and the bottom surface 10c indicates the correct assembly of the components 9, 10 and ensures a flat front plane S of the body 5, which preferably runs parallel to an adjacent roller 4. The flanging shoulders 13, 14 are positioned close to the front plane S of the body 5. In order to connect the components 9, 10 to one another, the components 9, 10 are welded together in the circumferential direction. Preferably by ultrasonic welding.

[0044] Fig. 6 shows a sectional view of the welded body 5 with a weld seam 15. The welded body 5 is installed in a roller grinder 3. The body 5 accommodates the axle 6 via bearing bores 9a1 and 10a. The body 5 is rotatably mounted on the axle 6, and the rollers 4 are screwed onto the axle 6 from the outside. The configuration of the components of the roller grinder 3 is selected such that the body 5 and the rollers 4 have exactly or essentially identical outer diameters. The outer surface 5a of the body 5 and a outer surface 4d of the rollers 4 are arranged flush with one another.

[0045] As shown in Fig. 6, the rollers 4 each have a circumferential rubber ring 7. For this purpose, at least one groove 4c is arranged on the outer circumference of the rollers 4. The rubber ring 7 has the largest diameter, preferably with respect to the axis 6 of the roller grinder 3, so that the rubber ring 7 rolls on the base U when the roller grinder 3 moves over the base U.

[0046] Although the invention has been described with reference to specific embodiments for the purpose of complete and clear disclosure, the appended claims are not to be so limited, but are to be interpreted to embody all modifications and alternative constructions that may reasonably occur to one skilled in the art that fall within the basic teachings presented herein. Additionally, the features of various implementation embodiments may be combined to form further embodiments of the invention.

[0047] List of reference symbols

[0048] 1 magnetic grinding gauge

[0049] 2 cutting tools (knives)

[0050] 2a blade

[0051] 2b Cutting edge

[0052] 3 roller grinders

[0053] 4 roller

[0054] 4a Grinding or polishing surface

[0055] 4b Bearing bore

[0056] 4c groove

[0057] 4d lateral surface

[0058] 5 bodies

[0059] 5a Shell surface

[0060] 5b front side

[0061] 5c Center hole

[0062] 6 axis

[0063] 6a Middle section

[0064] 6b stepped bearing section

[0065] 7 rubber ring

[0066] 8 Contact surface

[0067] 9 Component, housing component

[0068] 9a Recording

[0069] 9a 1 bearing bore

[0070] 9b floor section

[0071] 9c margin

[0072] 9d framework structure

[0073] 9e groove structure

[0074] 10 Component, insert component

[0075] 10a Bearing bore

[0076] 10b Floor section

[0077] 10c floor area

[0078] 10d framework structure

[0079] 10e rib structure

[0080] 11 Bearing sleeve

[0081] 12 rolling bearings

[0082] 13 paragraph

[0083] 14 paragraph

[0084] 15 Weld seam

[0085] X4, X5, X6 rotation axis

[0086] E Installation level

[0087] S frontal plane

[0088] Underground

Claims

Claims 1. A roller grinder (3) for grinding and / or polishing a cutting edge (2a) of a cutting tool (2), preferably a household knife, the roller grinder (3) comprising a body (5) and at least one grinding or polishing disc rotatable relative to the body (5), characterized in that the body (5) consists of two assembled components (9, 10) and is hollow at least in sections.

2. Roller grinder (3) according to the preceding claim, characterized in that the two components (9, 10) consist of plastic, preferably recycled plastic, and are preferably produced by injection molding.

3. Roller grinder (3) according to one of the preceding claims, characterized in that one of the components (9) forms a housing component (9) with a receptacle (9a), preferably in the axial direction, in which the other component (10) is inserted as an insert component (10).

4. Roller grinder (3) according to the preceding claim, characterized in that the housing component (9) encloses the insert component (10) in such a way that a bottom surface (10c) of the insert component (10) and an edge side (9c) of the housing component (9) lie flush in a front plane (S) of the body (5).

5. Roller grinder (3) according to one of the preceding claims, characterized in that the two components (9, 10) are cylindrical or cup-shaped, wherein in an assembled state one component (10) is inserted coaxially into the other component (9), preferably so that bottom sections (9b, 10b) of the components (9, 10) are opposite one another.

6. Roller grinder (3) according to one of the preceding claims, characterized in that the two components (9, 10) have at least in sections a framework structure (9d, 10d), in particular formed in a star, honeycomb, rib or lattice structure.

7. Roller grinder (3) according to one of the preceding claims, characterized in that rib and groove structures (9e, 10e) are formed on contact surfaces (11) of the components (9, 10) inserted into one another, which serve as engagement structures.

8. Roller grinder (3) according to one of the preceding claims, characterized in that on contact surfaces (11) of the components (9, 10) inserted into one another on the A circumferential shoulder (13, 14) is arranged on each end face (S) of the body (5), at which shoulder the components (9, 10) are preferably welded to one another, more preferably ultrasonically welded.

9. Roller grinder (3) according to one of the preceding claims, characterized in that the roller grinder (3) has two rollers (4) between which the body (5) is arranged, wherein the body (5) and the rollers (4) preferably have exactly or substantially identical outer diameters, preferably in such a way that a lateral surface (5a) of the body (5) and a lateral surface (4d) of the rollers (4) are arranged flush with one another.

10. Roll grinder (3) according to the preceding claim, characterized in that the rollers (4) each have a circumferential rubber ring (7), which is preferably arranged in at least one groove (4c) on the outer circumference of the rollers (4), wherein the rubber ring (7) preferably has the largest diameter with respect to an axis (6) of the roll grinder (3), so that the rubber ring (7) rolls on the base (U) when the roll grinder (3) is moved over the base (U).

11. Set comprising a roller grinder (3) according to one of the preceding claims and a magnetic grinding gauge (1), preferably a magnetic grinding gauge according to EP 4 210 901 A1.

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