Cutter sharpener

Abstract

Provided is a cutter sharpener comprising a body and a first polishing body that is disposed in the body and polishes a first blade that is a first type of blade, the body having, in a bottom surface, a bottom surface recess formed so as to be recessed toward an upper surface side in a width direction at a center part in a longitudinal direction, a cross section perpendicular to the longitudinal direction in the center part in the longitudinal direction of the body having a U-shape protruding downward, and a first slit being formed in a groove shape in the width direction in an upper surface of the body, and the first slit guiding a blade edge toward the first polishing body.

Description

knife sharpener

[0001] One aspect of the present invention relates to a knife sharpener for sharpening the cutting edge of a knife.

[0002] Conventionally, there is an electric grinding wheel that includes a motor, a grinding wheel fixed to the motor shaft, and a spring, as described in Patent Document 1. On the other hand, there is a blade sharpening tool that does not have a motor, as described in Patent Document 2, which includes a support that supports the grinding body, a base, and an elastic member and a guide member that are positioned between the support and the base.

[0003] Japanese Utility Model Application Publication No. 48-73893 Japanese Patent Application Publication No. 2018-122382

[0004] In recent years, the 3Rs have been advocated: Reduce, which refers to using things carefully and reducing waste; Reuse, which refers to repeatedly using usable items; and Recycle, which refers to reusing waste as a resource. As mentioned above, traditional razor blade cartridges were often made of resin and metal, but there is a need to replace them with materials that are easier to recycle. Furthermore, Goal 12 of the 17 Sustainable Development Goals (SDGs) adopted at the United Nations Summit, "Responsible Consumption and Production," calls for ensuring sustainable production and consumption patterns and drastically reducing waste generation. For example, Goal 12-5 calls for significantly reducing waste generation by 2030 through waste prevention, reduction, recycling, and reuse. Under these circumstances, there is a need to reduce waste generation in the field of blades, including kitchen knives.

[0005] On the other hand, knife sharpeners (knife sharpeners) for sharpening knives have not yet been widely adopted in ordinary households. The reasons for the lack of widespread adoption of knife sharpeners in ordinary households include the impression that they are difficult to use easily and safely, and the lack of storage space. Furthermore, conventional relatively compact knife sharpeners are difficult to install stably and prevent misalignment, resulting in the body moving during use. Furthermore, few sharpeners are designed to sharpen multiple types of blades. The present invention aims to address at least some of these issues while popularizing knife sharpeners in ordinary households, enabling blades to be used comfortably for extended periods of time and reducing waste generation.

[0006] The present invention provides a knife sharpener having the following configuration, for example.

[0007] One aspect of the present invention is a knife sharpener comprising: a main body; and a first sharpening body arranged within the main body for sharpening a first blade, which is a first type of blade; wherein the main body has a bottom recess formed in the center of the longitudinal direction so as to be recessed toward the upper surface across the width; a cross section of the main body at the center of the longitudinal direction, taken perpendicular to the longitudinal direction, is U-shaped with a convex downward side; and a first slit formed in the top surface of the main body is grooved across the width and forms a guide for the cutting edge toward the first sharpening body.

[0008] The above-mentioned knife sharpener features a recessed bottom surface, improving gripping, allowing the user to hold the sharpener securely and prevent it from slipping out of position. This prevents the sharpener from moving in the direction of the blade during use, ensuring safe use. While conventional sharpeners often require a guard member between the handle and the slit into which the blade tip is inserted to prevent the user's hand from slipping toward the slit, this sharpener is designed for sufficient safety without the need for such a guard member. Because the above-mentioned knife sharpener does not require such a guard member, its height can be reduced, making it easier to store compactly. Furthermore, the force applied by the user to the blade is effectively transferred to the blade tip, allowing the sharpener to be sharpened with relatively little force.

[0009] In the above-mentioned blade sharpener, preferably, a second sharpening body for sharpening a second blade of a different type from the first blade is further disposed within the main body, and a second slit is further formed on the upper surface of the main body in the shape of a groove extending in the width direction to guide the cutting edge toward the second sharpening body, and the first slit and the first sharpening body are disposed on one side of the main body in the longitudinal direction relative to the central portion, and the second slit and the second sharpening body are disposed on the other side of the main body in the longitudinal direction relative to the central portion.

[0010] According to the above-mentioned blade sharpener, the first slit and first sharpening body, and the second slit and second sharpening body are arranged on one side and the other side of the center in a balanced manner, so that each sharpening body can sharpen different types of blades, while still achieving a compact configuration. Furthermore, since the center of gravity can be positioned near the center, it is less likely to shift position, making it more stable during use.

[0011] In the above-described blade sharpener, the first blade is preferably a blade with a wavy cutting edge, and the second blade is preferably a blade with a straight or curved cutting edge.

[0012] When sharpening blades with wavy edges, blade sharpeners are particularly prone to misalignment, but the above-mentioned blade sharpener can stabilize the position during use.Furthermore, in recent years, high-quality bread has become more widely distributed than before, and as a result, the frequency of use of wavy-edged knives has increased.We can provide a blade sharpener that can sharpen both such wavy-edged knives and blades with straight or curved edges.

[0013] In the above-mentioned blade sharpener, preferably, a third sharpening body for sharpening the second blade is further disposed within the main body, a third slit is further formed on the upper surface of the main body in the shape of a groove extending in the width direction and for guiding the cutting edge toward the third sharpening body, and the third slit and the third sharpening body are disposed on the other side of the main body in the longitudinal direction relative to the central portion.

[0014] The above-described blade sharpener is configured to include the second and third sharpening bodies as sharpening bodies for sharpening a second blade having a straight or curved cutting edge, thereby enabling the effective sharpening of a second blade that is used more frequently. Furthermore, the second slit, the second sharpening body, the third slit, and the third sharpening body for sharpening the second blade are arranged adjacent to each other on the other side of the central portion, making it easy to sharpen the second blade.

[0015] In the above-described blade sharpener, the main body is preferably a substantially rectangular parallelepiped.

[0016] According to the above-described knife sharpener, it is possible to make it more compact, so that it can be easily stored, for example, in a kitchen drawer.

[0017] In the above-described blade sharpener, the bottom recess is preferably formed symmetrically with respect to the center of the body in the width direction.

[0018] According to the above-mentioned blade sharpener, when the first and second sharpening bodies are arranged on one side and the other side of the longitudinal center, respectively, the main body can be easily gripped by hooking the fingers into the recessed bottom surface regardless of which sharpening body is being used.Furthermore, the main body can be easily gripped regardless of dominant hand.

[0019] One aspect of the present invention is a knife sharpener comprising: a main body; and a sharpening body disposed within the main body; the main body has a bottom recess formed in the longitudinal center portion on the bottom surface thereof so as to be recessed in the width direction toward the upper surface; a cross section of the main body at the longitudinal center portion thereof perpendicular to the longitudinal direction is U-shaped with a convex downwards; the top surface of the main body has a slit formed in the shape of a groove extending in the width direction to guide the cutting edge toward the sharpening body; and no member protruding upwards is provided on the top surface of the main body.

[0020] The above-mentioned knife sharpener features a recessed bottom surface, improving grip and allowing the user to hold the sharpener securely without slipping. This prevents the sharpener from moving in the direction of the blade during use, ensuring safe use. While conventional sharpeners often require a guard member, projecting upward from the top surface of the body between the grip and the slit into which the blade is inserted, to prevent the user's hand from slipping into the slit, this sharpener is designed for sufficient safety without the need for such a guard member. Because the above-mentioned knife sharpener does not require such a guard member, its height can be reduced, allowing for compact storage. Furthermore, the force applied by the user to the blade is effectively transferred to the blade, allowing the sharpener to be sharpened with relatively little force.

[0021] One aspect of the present invention is a knife sharpener comprising: a main body; a first sharpening body arranged within the main body for sharpening a first blade which is a blade with a wavy cutting edge; a second sharpening body arranged within the main body for sharpening a second blade which is a blade with a straight or curved cutting edge; and a third sharpening body arranged within the main body for sharpening the second blade, wherein the third sharpening body has a finer grit than the second sharpening body; the main body has a bottom recess formed in the center of the longitudinal direction of the main body so as to be recessed towards the upper surface across the width direction, the bottom recess being formed symmetrically with respect to the center in the width direction of the main body; a cross section of the main body at the center of the longitudinal direction perpendicular to the longitudinal direction has a U-shape that is convex downward; and the top surface of the main body has: a first slit formed in the shape of a groove across the width direction to guide the cutting edge towards the first sharpening body; and a second slit formed in the shape of a groove across the width direction to guide the cutting edge towards the second sharpening body. a third slit formed in a groove shape across the width direction to guide the cutting edge toward the third grinding body, wherein the first slit and the first grinding body are arranged on one side of the body in the longitudinal direction relative to the central portion, and the second slit, the second grinding body, the third slit, and the third grinding body are arranged on the other side of the body in the longitudinal direction relative to the central portion.

[0022] In the above-mentioned blade sharpener, preferably, the first grinding body is made up of two plate-shaped grinding stones, the second grinding body is made up of grinding stones in the shape of two truncated cones connected to each other by their top surfaces, each of which has an area smaller than that of its bottom surface, and the third grinding body is made up of two cylindrical grinding stones.

[0023] Fig. 1 is a perspective view of a knife sharpener. Fig. 2 is a perspective view of the knife sharpener with the cover removed. Fig. 3 is a perspective view of the knife sharpener with the cover removed. Fig. 4 is a view of the cover as seen from the bottom side. Fig. 5 is a bottom view of the knife sharpener. Fig. 6 is a side view of the knife sharpener. Fig. 7 is a perspective view of the knife sharpener. Fig. 8 is a cross-sectional view of the knife sharpener at the position A-A in Fig. 6.

[0024] The knife sharpener of the present invention will be described in detail with reference to the drawings. However, the embodiment described below is merely an example of the present invention and is not intended to limit the technical scope of the present invention. In each drawing, the same components are given the same reference numerals, and their description may be omitted. In this specification, the upper and lower sides in the vertical direction are referred to as the upper and lower sides, respectively, based on the state in which the knife sharpener 1 is placed during use, and the lower surface is referred to as the bottom surface or lower surface, and the upper surface is referred to as the top surface.

[0025] <Configuration of Knife Sharpener> As shown in Figures 1 and 2, etc., knife sharpener 1 includes a base 2 and a cover 3. When base 2 and cover 3 are connected, knife sharpener 1 becomes main body 4, which includes multiple sharpening bodies for sharpening knives. As shown in Figure 1, main body 4 is a rounded, approximately rectangular parallelepiped, and its bottom surface is formed with a bottom surface recess 25, which will be described later. Knife sharpener 1 can sharpen serrated knives, which are blades with a wavy cutting edge, and double-edged knives, which are blades with a straight or curved cutting edge. In other words, main body 4 is the housing (case) of knife sharpener 1.

[0026] <Base 2> The base 2 is part of the main body 4 and constitutes the bottom of the blade sharpener 1. The base 2 supports the first abrasive body 21, the second abrasive body 22, and the third abrasive body 23, which are the respective components of the blade sharpener 1. That is, the first abrasive body 21, the second abrasive body 22, and the third abrasive body 23 are disposed inside the main body 4, which is made up of the base 2 and the cover 3. The base 2 has two screw holes 24, which are each a through-hole, and is connected to the cover 3 by screws 24a inserted through the screw holes 24. The screw holes 24 may have a screw thread formed therein, but may also be a through-hole without a screw thread formed therein.

[0027] As shown in Figures 1 and 6, the base 2 has a bottom recess 25 formed on its bottom surface in the longitudinal center portion, recessed toward the upper surface in the width direction. The bottom recess 25 has a seamless curved surface configuration. In other words, the bottom recess 25 is formed in a gently curved shape with rounded corners. Figure 8 is a cross-sectional view of the blade sharpener 1 taken along line A-A in Figure 6. That is, Figure 8 is a cross-sectional view of the blade sharpener 1 taken along a plane perpendicular to the longitudinal direction at the longitudinal center portion. As shown in Figure 8, in the cross-section perpendicular to the longitudinal direction of the base 2, the central portion of the base 2 has a U-shape that is convex downward. The bottom recess 25 is formed symmetrically with respect to the center in the width direction of the base 2. The bottom recess 25 is formed so that when the user grips the main body 4 of the knife sharpener 1 from above during use, the user's fingers can rest on it, thereby enabling the user to hold the knife sharpener 1 stably.

[0028] 3, the base 2 is rectangular in plan view from above. The base 2 has a first abrasive body 21 on one side of the longitudinal center of the blade sharpener 1, and a second abrasive body 22 and a third abrasive body 23 on the other side. These abrasive bodies are arranged in the order of the first abrasive body 21, the third abrasive body 23, and the second abrasive body 22 from one side of the blade sharpener 1.

[0029] As shown in Figures 5 and 7, a U-shaped hook 26 is provided on the bottom surface of the base 2. The hook 26 is rotatably connected to the bottom surface of the base 2 at two connecting portions 26a. By rotating the hook 26 around the connecting portions 26a as a rotation axis, the hook 26 can be changed from the stored state shown in Figure 5 to the unfolded state shown in Figure 7. In the unfolded state shown in Figure 7, the hook 26 can be stored by hanging it on a hook or the like provided on a wall in the kitchen.

[0030] <First abrasive body 21, second abrasive body 22, third abrasive body 23> As shown in Figures 2 and 3, the first abrasive body 21 is arranged below the first slit 31. The first abrasive body 21 is a grindstone for grinding a serrated blade knife, and is made up of two plate-shaped grindstones, the first grindstones 21a. The first grindstones 21a are made of, for example, cemented carbide. Each end face of the first grindstones 21a abuts against the cutting edge of the serrated blade knife, allowing the grindstone to be ground. The first abrasive body 21 is supported by being clamped at its bottom and sides by the base 2.

[0031] As shown in Figures 2 and 3, the second grinding body 22 is positioned below the second slit 32. The second grinding body 22 is a whetstone for initially sharpening a double-edged knife, and is made of a second grinding stone 22a, which is a grinding stone in the shape of two truncated cones, each with an upper surface that is smaller than the bottom surface and connected to each other. The second grinding stone 22a is made of, for example, ceramic. The side of the second grinding stone 22a abuts against the cutting edge of the double-edged knife, allowing it to sharpen the double-edged knife. The second grinding body 22 has a central axis 22b that passes through the center, and this central axis is supported by the base 2.

[0032] As shown in Figures 2 and 3, the third grinding body 23 is disposed below the third slit 33. The third grinding body 23 is a whetstone for finish grinding of the double-edged knife that has been ground by the second grinding body 22, and is a whetstone with a finer grit than the second grinding body 22. The third grinding body 23 is made of two cylindrical grinding stones, the third grinding stones 23a. The third grinding stones 23a are formed from, for example, ceramic. The side surfaces of the third grinding stones 23a come into contact with the cutting edge of the double-edged knife, allowing the double-edged knife to be ground. The side surfaces and bottom end of the third grinding stone 23a are supported by the base 2.

[0033] <Cover 3> The cover 3 is part of the main body 4 and constitutes the upper part of the blade sharpener 1. As shown in FIGS. 1 and 2 , a first slit 31, a second slit 32, and a third slit 33 are formed on the top surface of the cover 3. The first slit 31, the second slit 32, and the third slit 33 are each formed as a groove extending from the top surface of the cover 3 downward across the width of the cover 3. The first slit 31, the second slit 32, and the third slit 33 are each formed as a linear groove extending vertically. The first sharpening body 21, the second sharpening body 22, and the third sharpening body 23, which are supported by the base 2, are disposed below the first slit 31, the second slit 32, and the third slit 33, respectively. The first slit 31 is located on one side of the longitudinal center of the blade sharpener 1, and the second slit 32 and the third slit 33 are located on the other side. These slits are formed in the order of first slit 31, third slit 33, and second slit 32 from one side of the blade sharpener 1. The first slit 31, second slit 32, and third slit 33 guide the cutting edge of the blade to be sharpened toward the first sharpening body 21, second sharpening body 22, and third sharpening body 23, respectively.

[0034] The cover 3 has curved recesses 3 b formed on both side surfaces 3 a thereof, the curved recesses 3 b being curved upward along the bottom recesses 25 .

[0035] The cover 3 is formed with two screw holes 34 into which the screws 24a inserted through the screw holes 24 of the base 2 are inserted. The screw holes 34 are internally threaded.

[0036] As shown in FIG. 6 , icons 31a, 32a, and 33a are provided on the side surface 3a of the cover 3 adjacent to the first slit 31, the second slit 32, and the third slit 33, respectively, as usage guides. The icons 31a, 32a, and 33a indicate the type of blade to be sharpened in the adjacent first slit 31, the second slit 32, and the third slit 33, respectively, and indicate the number of times the blade to be sharpened should be slid when sharpening. The icons 31a to 33a are provided not only on one side surface 3a of the cover 3 shown in FIG. 6 , but also on the side opposite to this side surface 3a. Providing the icons 31a to 33a on both sides makes the icons 31a to 33a easier to see, regardless of the user's dominant hand.

[0037] 6 and 1, the length L1 of the main body 4 of the knife sharpener 1 in the longitudinal direction is 135 mm, the length L2 in the width direction is 36 mm, and the length in the vertical direction, i.e., the height L3, is 40 mm. The length L4 of the bottom recess 25 in the longitudinal direction is 74 mm, and the length in the vertical direction, i.e., the height L5, is 28 mm. The height L6 of the bottom recess 25 at the center in the width direction, where the height is lowest, is 13 mm.

[0038] This size improves grip, and when a user holds the main body 4, the user's fingers can fit into the bottom recess 25 to some extent, making the main body 4 less likely to tip over and making it easier to apply force from above during use. In addition, the curved shape of the bottom recess 25 allows the user to hold the main body 4 with a good feel.

[0039] <Using the Knife Sharpener 1> As described above, the knife sharpener 1 can be used to sharpen serrated knives and double-edged knives. When sharpening a serrated knife, the user can recognize that the first slit 31 and the first sharpening body 21 are for sharpening a serrated knife by looking at the icons 31a to 33a (especially icon 31a). The user inserts the cutting edge of the serrated knife to be sharpened through the first slit 31 and, guided by the first slit 31, brings the cutting edge into contact with the first sharpening body 21. The user then sharpens the cutting edge of the serrated knife by sliding it toward themselves. The user can repeat this sharpening operation the number of times indicated by the guide of the icon 31a. In this manner, the knife sharpener 1 can be used to sharpen a serrated knife.

[0040] On the other hand, when sharpening a double-edged knife, the user can recognize by looking at the icons 31a to 33a (especially icons 32a and 33a) that the double-edged knife should first be sharpened using the second slit 32 and the second sharpening body 22, and then using the third slit 33 and the third sharpening body 23. The user first inserts the cutting edge of the double-edged knife to be sharpened through the second slit 32 and brings the cutting edge into contact with the second sharpening body 22 while being guided by the second slit 32. The user then sharpens the cutting edge of the double-edged knife by sliding it toward themselves. The user can repeat the sharpening operation using the second sharpening body 22 the number of times indicated by the guide of the icon 32a. The user then inserts the cutting edge of the double-edged knife to be sharpened through the third slit 33 and sharpens the cutting edge using the third sharpening body 23 in the same manner. The user can repeat the sharpening operation using the third sharpener 23, using the number of times indicated by the guide icon 33a as a guide. In this manner, the double-edged knife can be sharpened using the blade sharpener 1.

[0041] <Modifications> The knife sharpener of the above embodiment can employ the following modifications. Note that the modifications described below should not be interpreted as limiting the present invention, but are described as specific examples.

[0042] In the embodiment, a serrated knife and a double-edged knife are the blades to be sharpened, but for example, a serrated knife and a single-edged knife, or a double-edged knife and a single-edged knife may also be the blades to be sharpened. In this case, a sharpening body suitable for the blade to be sharpened is used. However, it is preferable to configure the embodiment so that a double-edged knife and a serrated knife, which are often used in ordinary households, are the blades to be sharpened.

[0043] The abrasive bodies used in the knife sharpener 1 of the embodiment are not limited to the first abrasive body 21, the second abrasive body 22, and the third abrasive body 23 described in the embodiment, and can be changed as appropriate. Furthermore, in the configuration of the embodiment, the first abrasive body 21 is used as one abrasive body for the serrated blade knife, and the second abrasive body 22 and the third abrasive body 23 are used as two abrasive bodies for the double-edged blade knife, but the configuration is not limited to this. In other words, two or more abrasive bodies may be used for the serrated blade knife, and one or three or more abrasive bodies may be used for the double-edged blade knife. However, it is preferable to use the configuration of the embodiment in which the abrasive bodies are arranged in a balanced manner.

[0044] Although the blade sharpener 1 of the embodiment does not employ a configuration in which the sharpening bodies are rotationally driven by a motor or the like, the sharpening bodies may be rotationally driven by a motor or the like. In this case, only one of the sharpening bodies may be rotationally driven, or all of the sharpening bodies may be rotationally driven.

[0045] <Features of the embodiment> The knife sharpener of one embodiment described above by exemplifying the embodiment and the modified examples has the following features.

[0046] The knife sharpener 1 comprises a main body 4 including a base 2 and a cover 3, and a first sharpening body 21 disposed within the main body 4 for sharpening a first type of knife (e.g., a serrated knife). The main body 4 has a bottom recess 25 formed in the center of the longitudinal direction on the bottom surface, recessed in the width direction toward the upper surface. A cross section of the main body 4 at the center of the longitudinal direction, taken perpendicular to the longitudinal direction (see FIG. 8 ), has a U-shape with a downwardly convex shape. The top surface of the main body 4 has a first slit 31 formed in the shape of a groove extending in the width direction, which guides the cutting edge toward the first sharpening body 21.

[0047] The blade sharpener 1, with its bottom recess 25, provides enhanced grip, allowing the user to hold the sharpener 1 securely and without misalignment. This prevents the sharpener 1 from moving in the direction of the blade during use, ensuring safe use. While conventional sharpeners often require a guard member between the handle and the slit into which the blade tip is inserted to prevent the user's hand from slipping toward the slit, this configuration eliminates the need for such a guard member, making the sharpener 1 safer and more reliable. Because the blade sharpener 1 does not require such a guard member, its height can be reduced, allowing for easier compact storage. Furthermore, the force exerted by the user on the blade is effectively transferred to the blade tip, allowing the user to sharpen the blade with relatively little force.

[0048] In the above-described blade sharpener 1, it is preferable that the upper surface of the main body 4 (the upper surface of the cover 3) is not provided with any member that protrudes upward.

[0049] Furthermore, the knife sharpener 1 has a second sharpening body 22 disposed within the main body 4 for sharpening a second blade (e.g., a double-edged knife) of a different type from the first blade (e.g., a serrated blade knife). A second slit 32 is further formed on the top surface of the main body 4, in the shape of a groove extending across the width and guiding the cutting edge toward the second sharpening body 22. The first slit 31 and the first sharpening body 21 are disposed on one side of the longitudinal center of the main body 4, and the second slit 32 and the second sharpening body 22 are disposed on the other side of the longitudinal center of the main body 4.

[0050] With this blade sharpener 1, the first slit 31 and first sharpening body 21, and the second slit 32 and second sharpening body 22 are arranged on one side and the other side of the center in a balanced manner, allowing each sharpening body to sharpen different types of blades, while still achieving a compact configuration. Furthermore, since the center of gravity can be positioned near the center, it is less likely to shift position, making it more stable during use.

[0051] The knife sharpener 1 is configured to sharpen a serrated knife with a wavy cutting edge as the first knife, and to sharpen a straight or curved knife with a straight or curved cutting edge (for example, a double-edged knife) as the second knife.

[0052] When sharpening blades with wavy edges, blade sharpeners are particularly prone to misalignment, but the above-mentioned blade sharpener 1 can stabilize the position during use. In recent years, high-quality bread has become more widely distributed than before, and as a result, the frequency of use of wavy-edged knives has increased. This invention provides a blade sharpener that can sharpen both such wavy-edged knives and blades with straight or curved edges.

[0053] Furthermore, the knife sharpener 1 further includes a third sharpening body 23 disposed within the main body 4 for sharpening a second blade (e.g., a double-edged knife). A third slit 33 is formed in the upper surface of the main body 4, and is groove-shaped across the width to guide the cutting edge toward the third sharpening body 23. The third slit 33 and the third sharpening body 23 are disposed on the other side of the center of the main body 4 in the longitudinal direction.

[0054] The blade sharpener 1 is configured to include the second sharpening body 22 and the third sharpening body 23 as sharpening bodies for sharpening a second blade having a straight or curved cutting edge (for example, a double-edged knife), so that it can be configured to effectively sharpen a second blade that is used more frequently. Also, the second slit 32, the second sharpening body 22, the third slit 33, and the third sharpening body 23 for sharpening the second blade are configured to be adjacent to each other on the other side of the center portion, so that it is easy to sharpen the second blade.

[0055] Furthermore, since the main body 4 of the knife sharpener 1 is a substantially rectangular parallelepiped, it can be made more compact and can be easily stored, for example, in a kitchen drawer.

[0056] Furthermore, in the knife sharpener 1, the bottom recess 25 is formed symmetrically with respect to the center in the width direction of the main body 4. The knife sharpener 1 is configured such that the first abrasive body 21 is disposed on one side of the center in the longitudinal direction, and the second abrasive body 22 and the third abrasive body 23 are disposed on the other side. Therefore, a user may grip one side to use the second abrasive body 22 and the third abrasive body 23, or may grip the other side to use the first abrasive body 21. In this case, as described above, the bottom recess 25 is formed symmetrically with respect to the center in the width direction of the main body 4, making it easy to grip the main body 4 by hooking a finger on the bottom recess 25 in either case. Furthermore, the main body 4 is configured to be easy to grip regardless of dominant hand.

[0057] As shown in the embodiment, the knife sharpener 1 can be configured to include a main body 4, a first abrasive body 21 arranged within the main body 4 for sharpening a first blade having a wavy cutting edge, a second abrasive body 22 for sharpening a second blade having a straight or curved cutting edge, and a third abrasive body 23 for sharpening the second blade. The third abrasive body 23 has a finer grit than the second abrasive body 22. The main body 4 has a bottom recess 25 formed in the longitudinal center of the main body 4, recessed toward the upper surface across the width. A cross section of the main body 4 at the longitudinal center, taken perpendicular to the longitudinal direction (see FIG. 8 ), is U-shaped with a convex downward projection. The top surface of the main body 4 has a first slit 31, a second slit 32, and a third slit 33. The first slit 31 is formed as a groove extending across the width and guides the cutting edge toward the first abrasive body 21. The second slit 32 is formed as a groove extending in the width direction and guides the cutting edge toward the second abrasive body 22. The third slit 33 is formed as a groove extending in the width direction and guides the cutting edge toward the third abrasive body 23. The first slit 31 and the first abrasive body 21 are arranged on one side in the longitudinal direction of the main body 4 with respect to the center part in the longitudinal direction of the main body 4, and the second slit 32, the second abrasive body 22, the third slit 33, and the third abrasive body 23 are arranged on the other side in the longitudinal direction of the main body 4 with respect to the center part.

[0058] Furthermore, in the above, the first polishing body 21 can be composed of two plate-shaped first grinding stones 21a, the second polishing body 22 can be composed of two second grinding stones 22a each having a shape of two truncated cones connected to each other by their top surfaces, each of which has an area smaller than that of the bottom surface, and the third polishing body 23 can be composed of two cylindrical third grinding stones 23a.

[0059] The knife sharpener 1, with its configuration and size as described above, is compact and can be stored in a convenient place such as a kitchen drawer, allowing for easy resharpening of knives, ensuring that knives are always sharp. It can also be stored in a kitchen drawer, helping to keep the kitchen tidy. Despite its compact size, the knife sharpener 1 can be held firmly and steadily to sharpen knives and other tools. The knife sharpener 1 can also sharpen multiple types of blades, despite its compact configuration.

[0060] REFERENCE SIGNS LIST 1... Knife sharpener 2... Base 21... First sharpener 22... Second sharpener 23... Third sharpener 24... Screw hole 24a... Screw 25... Bottom recess 26... Hook 3... Cover 31... First slit 32... Second slit 33... Third slit 31a to 33a... Icon 34... Screw hole 4... Main body

Claims

1. A knife sharpener comprising: a main body; and a grinding body disposed within the main body, wherein the main body has a bottom surface with a bottom surface recess formed in the longitudinal center part so as to be recessed toward the upper surface across the width direction, a cross section of the main body at the longitudinal center part perpendicular to the longitudinal direction has a U-shape that is convex downward, and the upper surface of the main body has a groove-like shape formed across the width direction and a slit that guides the cutting edge toward the grinding body.

2. A knife sharpener as described in claim 1, wherein the grinding body is a first grinding body for grinding a first blade, the slit is a first slit, a second grinding body for grinding a second blade of a different type from the first blade is further disposed within the main body, a second slit is further formed on the upper surface of the main body in the shape of a groove extending in the width direction and guiding the cutting edge toward the second grinding body, the first slit and the first grinding body are disposed on one side of the main body in the longitudinal direction relative to the central portion, and the second slit and the second grinding body are disposed on the other side of the main body in the longitudinal direction relative to the central portion.

3. The blade sharpener according to claim 2, wherein the first blade is a blade with a wavy cutting edge, and the second blade is a blade with a straight or curved cutting edge.

4. A knife sharpener as described in claim 2, wherein a third grinding body for grinding the second blade is further disposed within the main body, and a third slit is further formed on the upper surface of the main body, the third slit being groove-shaped across the width direction and guiding the cutting edge towards the third grinding body, and the third slit and the third grinding body are disposed on the other side of the main body in the longitudinal direction relative to the central portion.

5. The knife sharpener according to claim 2, wherein the main body is substantially rectangular.

6. The blade sharpener according to claim 2, wherein the bottom recess is formed symmetrically with respect to the center in the width direction of the main body.

7. A knife sharpener comprising: a main body; and a grinding body disposed within the main body, wherein the main body has a bottom surface with a bottom surface recess formed in the longitudinal center part so as to be recessed toward the upper surface across the width direction, a cross section of the main body at the longitudinal center part perpendicular to the longitudinal direction has a U-shape convex downward, the upper surface of the main body has a slit formed in a groove shape across the width direction for guiding the cutting edge toward the grinding body, and the upper surface of the main body is free of any member protruding upward.

8. A knife sharpener comprising: a main body; a first abrasive body arranged within the main body for sharpening a first blade having a wavy cutting edge; a second abrasive body arranged for sharpening a second blade having a straight or curved cutting edge; and a third abrasive body arranged for sharpening the second blade, wherein the third abrasive body has a finer grain size than the second abrasive body; the main body has a bottom surface recess formed in the longitudinal center of the main body so as to be recessed toward the upper surface across the width direction, the bottom surface recess being formed symmetrically with respect to the center in the width direction of the main body; a cross section of the main body perpendicular to the longitudinal direction at the longitudinal center has a U-shape convex downward; and the top surface of the main body has: a first slit formed in a groove shape across the width direction for guiding the cutting edge toward the first abrasive body; and a second slit formed in a groove shape across the width direction for guiding the cutting edge toward the second abrasive body. a third slit formed in a groove shape extending across the width direction and guiding the cutting edge toward the third abrasive body, wherein the first slit and the first abrasive body are positioned on one side of the body in the longitudinal direction relative to the central portion, and the second slit, the second abrasive body, the third slit, and the third abrasive body are positioned on the other side of the body in the longitudinal direction relative to the central portion.

9. A knife sharpener as described in claim 8, wherein the first grinding body is made of two plate-shaped grinding stones, the second grinding body is made of a grinding stone having a shape of two truncated cones connected to each other by their top surfaces, each of which has an area smaller than that of their bottom surfaces, and the third grinding body is made of two cylindrical grinding stones.

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