Method of forming teeth for a cutting blade or guard

Abstract

The present invention relates to a method (200) for forming teeth of a cutting blade or guard, the method comprising: a) obtaining (210) a blank of material, the blank having an upper outer surface and a lower outer surface, wherein at least a portion of the lower outer surface is substantially planar and forms the plane of the blank; b) utilizing (220) a cutting device (20) comprising a first die (40) and a second die (50); c) placing (230) the blank in the cutting device; d) moving the first die and the second die relative to each other (240) such that the first plane moves toward and passes through the second plane such that each of a plurality of first elements passes at least partially between adjacent elements of the plurality of second elements; and e) after step d), utilizing a bending device (250) to bend an edge portion (82) of the teeth of the cutting blade or guard extending below the plane of the blank back toward the plane of the blank.

Description

Technical Field

[0001] The present invention relates to a method of forming a plurality of teeth of a cutting blade or guard, and a cutting and bending system for forming a plurality of teeth of a cutting blade or guard. Background Art

[0002] The performance of hair cutting systems, such as trimmers and shavers, depends on metal cutting edges that cut hair. These cutting edges are present on guards and / or cutting blades. As is well known, in order to obtain excellent hair cutting performance, it is preferred that the cutting edges have acute angles (angles less than 90 degrees) and are sharp. Typically, a sharp cutting edge is a cutting edge with a small tip radius.

[0003] This preferred geometry cannot be made using conventional cold forming techniques. For example, stamping will result in straight angles, while forging will result in blunt cutting edges. Other manufacturing techniques will make the geometry possible; however, these techniques are more complex and therefore more expensive.

[0004] For example, patent document EP 1354674 A1 discloses a method for manufacturing a hair clipper blade, which includes providing a blank having a comb-tooth-shaped cutting edge portion, and forging the cutting edge portion to have a sharp tip angle.

[0005] It is necessary to solve this problem. Summary of the invention

[0006] It would be advantageous to have an improved device for manufacturing teeth of a guard and / or cutting blade of a shaver and / or trimmer. The objects of the invention are achieved by the subject matter of the independent claims, wherein further embodiments are incorporated in the dependent claims. It should be noted that the following described aspects and examples of the invention also apply to: a method of forming a plurality of teeth of a cutting blade or guard, a cutting blade or guard having a plurality of teeth formed by the method, and a cutting and bending system for forming a plurality of teeth of a cutting blade or guard.

[0007] In a first aspect, there is provided a method of forming a plurality of teeth of a cutting blade or guard, the method comprising:

[0008] a) obtaining a billet of material, the billet having an upper outer surface and a lower outer surface, wherein at least a portion of the lower outer surface is substantially planar and forms a plane of the billet;

[0009] b) using a cutting apparatus comprising a first die and a second die, wherein the first die comprises a plurality of first elements, and the second die comprises a plurality of second elements, wherein a first plane is defined relative to upper surfaces of the plurality of first elements; and a second plane is defined relative to lower surfaces of the plurality of second elements, and wherein each upper surface of the plurality of first elements has a central portion and an edge portion, the central portion being located in the first plane and the edge portion being below the first plane;

[0010] c) placing the blank in a cutting device so that a portion of the lower outer surface faces the upper surfaces of the plurality of first elements and a portion of the upper outer surface faces the lower surfaces of the plurality of second elements;

[0011] d) moving the first die and the second die relative to each other such that the first plane moves toward and through the second plane such that each of the plurality of first elements is at least partially between adjacent ones of the plurality of second elements, and wherein teeth of the cutting blade or guard are formed corresponding to the positions of the plurality of first elements, and wherein the teeth have a lower outer surface formed by a lower outer surface of the blank;

[0012] e) After step d), edge portions of the teeth of the cutting blade or guard extending below the plane of the blank are bent back towards the plane of the blank using a bending device.

[0013] In other words, a cutting element of a cutting piece / guard for hair cutting is formed using a cutting and bending process. The stamping of the process cuts the teeth of a cutting blade or guard, and the teeth intentionally have an edge portion protruding below the plane of the cutting blade or guard. Then, the bending portion of the process bends these edge portions back, basically bends back in the lower plane of the teeth, and these edge portions form the sharp and solid cutting edge of the teeth of the cutting blade or guard. Therefore, a process is provided to form this cutting blade / guard, teeth with these sharp cutting edges, and the process is more environmentally friendly than other technologies such as etching. The cutting edge can have a wedge angle less than 90 degrees.

[0014] Thus, the method can be used to form cutting blades (typically the moving part in a shaving / trimming device) as well as guard elements (e.g., elements that come into contact with the skin and cover the cutting element). The teeth formed for cutting blades and guards can be applied to all forms of shaving and trimming elements, e.g., linear or rotary systems, such as rotary shavers.

[0015] In an example, in step e), the bending device comprises a first plate comprising a substantially planar upper surface; and wherein the method comprises step f): bending an edge portion of a tooth of a cutting blade or guard by pushing the planar upper surface of the first plate against a lower outer surface of the tooth.

[0016] Thus, the substantially planar upper surface of the plate can be pushed upwardly against a portion of the cutting blank, which may be flat or curved but is substantially flat over the area where the teeth have been cut, and the plate pushing upwardly against that portion of the blank bends the cutting edge of the tooth to form a sharp cutting edge of the tooth.

[0017] In the example, the first die and the second die of the cutting device are configured so that in step d), when each of the plurality of first elements passes at least partially between adjacent elements of the plurality of second elements, elements of the plurality of first elements are laterally spaced apart from elements of the plurality of second elements by a distance less than or equal to 10% of the thickness of the blank, wherein the thickness of the blank is equal to the distance between a portion of the upper outer surface and a portion of the lower outer surface.

[0018] Therefore, the spacing between the dies used for cutting is less than normal, and it has been found advantageously that this forms teeth with edge portions of the correct size, which can then be bent back to form the cutting edges of those teeth. The smaller spacing means that the edge portions formed "stick out", meaning that the width from edge portion to edge portion is greater than the width of the body of the tooth.

[0019] In an example, each element of the plurality of first elements includes a curved upper surface.

[0020] In an example, each element of the plurality of first elements is chamfered.

[0021] In an example, the bending device includes a second plate comprising a plurality of recesses, wherein the depth of each recess is less than the thickness of the blank, wherein the thickness of the blank is equal to the distance between a portion of the upper outer surface and a portion of the lower outer surface; and wherein in step f), bending the edge portion of the teeth of the cutting blade or guard includes: positioning the teeth within the plurality of recesses and moving the first plate and the second plate toward each other.

[0022] In this way, in a simple process of pushing two plates together, sandwiching the teeth of the cutting blade or guard therebetween, the edges of the teeth can be bent back, essentially into the bottom plane of the teeth.

[0023] In an example, openings of the plurality of recesses are located in a lower surface of the second plate, wherein a width of each opening at the lower surface is wider than a width of each cutting tooth, and wherein in step f), the lower surface of the second plate faces an upper surface of the first plate.

[0024] In this manner, the edge portion, when bent back "upwardly," may have an edge extent from one side of the cutting tooth to the opposite side that is wider than the body of the cutting tooth.

[0025] The tooth need not have a wider width at the location of the cutting edge formed by the bent edge portion than in the rest of the tooth.

[0026] In an example, each bottom of the plurality of recesses has a flat portion and has rounded corners on both sides of the recess, the width of the flat portion being smaller than the width of each cutting tooth, the rounded corners extending from the flat portion to side portions on both sides of the recess, the side portions being spaced apart from each other by a distance greater than the width of each cutting tooth.

[0027] This provides additional force applied to the edge of the tooth where it is desired to bend the edge portion back, thereby providing improved bending and the material can be bent back further so that the bottom surface of the material moves towards the bottom plane of the tooth of the cutting blade or guard.

[0028] In a third aspect, there is provided a cutting and bending system for forming a plurality of teeth of a cutting blade or guard, the cutting and bending system comprising:

[0029] - cutting equipment; and

[0030] - Bending equipment.

[0031] The cutting device includes a first die and a second die. The first die includes a plurality of first elements, and the second die includes a plurality of second elements. A first plane is defined relative to the upper surfaces of the plurality of first elements, and a second plane is defined relative to the lower surfaces of the plurality of second elements. Each upper surface of the plurality of first elements has a central portion located in the first plane and an edge portion below the first plane. The cutting device is configured so that a blank of material can be placed in the cutting device. The blank includes an upper outer surface and a lower outer surface. At least a portion of the lower outer surface is substantially planar and forms a plane of the blank. When the blank is placed in the cutting device, a portion of the lower outer surface faces the upper surfaces of the plurality of first elements, and a portion of the upper outer surface faces the lower surfaces of the plurality of second elements. The first die and the second die of the cutting device are configured to move relative to each other so that the first plane moves toward and passes through the second plane so that each of the plurality of first elements passes at least partially between adjacent elements of the plurality of second elements. When the blank is placed in the cutting device and cut by the cutting device, the teeth of the cutting blade or guard are formed corresponding to the positions of the plurality of first elements. The teeth have a lower outer surface formed by the lower outer surface of the blank. When the blank has been cut by the cutting device, the edge portion of the teeth of the cutting blade or guard extends below the plane of the blank. The bending device is configured to bend the edge portion of the teeth of the cutting blade or guard extending below the plane of the blank back towards the plane of the blank after cutting.

[0032] In examples, at least a portion of the upper outer surface is substantially planar.

[0033] In an example, a portion of the upper outer surface is substantially parallel to a portion of the lower outer surface.

[0034] In an example, a portion of the upper outer surface is angled with a portion of the lower outer surface.

[0035] In an example, the bending device comprises a first plate including a substantially planar upper surface. The bending device is configured to bend an edge portion of a tooth of a cutting blade or guard including the planar upper surface of the first plate urged against a lower outer surface of the tooth.

[0036] In an example, the first die and the second die of the cutting apparatus are configured such that when each of the plurality of first elements passes at least partially between adjacent elements of the plurality of second elements, an element of the plurality of first elements is laterally spaced apart from an element of the plurality of second elements by a distance less than or equal to 10% of a thickness of the blank, the thickness of the blank being equal to a distance between a portion of the upper outer surface and a portion of the lower outer surface.

[0037] In an example, each element of the plurality of first elements has a cut corner.

[0038] In an example, the outer edge of the chamfer is located below the first plane at a distance greater than 6% of the thickness of the blank. The thickness of the blank is equal to the distance between a portion of the upper outer surface and a portion of the lower outer surface.

[0039] In an example, the bending device includes a second plate including a plurality of recesses. The depth of each recess is less than the thickness of the blank. The thickness of the blank is equal to the distance between a portion of the upper outer surface and a portion of the lower outer surface. The second plate is configured so that the teeth of the cutting blade or guard can be located in the plurality of recesses, wherein each tooth is located in a separate recess. The bending device is configured to bend the edge portion of the teeth of the cutting blade or guard, which includes moving the first plate and the second plate toward each other.

[0040] In an example, the openings of the plurality of recesses are located in the lower surface of the second plate. The width of each opening at the lower surface is wider than the width of each cutting tooth. The lower surface of the second plate faces the upper surface of the first plate.

[0041] In an example, each bottom of the plurality of recesses has a flat portion having a width less than the width of each cutting tooth, and has rounded corners on both sides of the recess extending from the flat portion to side portions on both sides of the recess, the side portions being spaced apart from each other by a distance greater than the width of each cutting tooth.

[0042] Advantageously, the benefits provided by any of the above aspects also apply to all other aspects, and vice versa.

[0043] The above aspects and examples will be apparent from and elucidated with reference to the embodiments described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Exemplary embodiments will be described below with reference to the following drawings:

[0045] Figure 1 A method of forming a plurality of teeth of a cutting blade or guard is shown;

[0046] Figure 2 A schematic illustration of a plurality of teeth of a cutting blade or guard showing cutting;

[0047] Figure 3 Schematic illustration showing teeth of a cutting blade or guard being bent;

[0048] Figure 4 Schematic illustration showing the teeth of a cutting blade or guard to be cut;

[0049] Figure 5 On the left side, it indicates Figure 4 A forming step after that, showing a schematic example of a cutting blade or a tooth of a guard being cut, and a forming step subsequent to the cutting step, showing a schematic example of a cutting blade or a tooth of a guard being bent, are shown on the right;

[0050] Figure 6 A schematic illustration of a plurality of teeth of a cutting blade or guard being cut is shown;

[0051] Figure 7 As shown in Figure 6 Schematically shown, Figure 6 An example of a bottom cutting die in the area within the box shown, but where a top cutting die is not present;

[0052] Figure 8 a schematic illustration showing the teeth of a cutting blade or guard being cut; and

[0053] Fig. 9 and Fig.10 Examples of teeth of a cutting blade or guard formed by the new method are shown. DETAILED DESCRIPTION

[0054] Figure 1 A method 200 of forming a plurality of teeth of a cutting blade or guard is shown in its basic steps, wherein the necessary steps are shown in solid lines. The method 200 comprises:

[0055] In an acquisition step 210, also referred to as step a), a blank of material is acquired, the blank having an upper outer surface and a lower outer surface, wherein at least a portion of the lower outer surface is substantially planar and forms a plane of the blank;

[0056] In utilizing step 220, also referred to as step b), utilizing a cutting apparatus 20 comprising a first die 40 and a second die 50, wherein the first die comprises a plurality of first elements 42, and the second die comprises a plurality of second elements 52, wherein a first plane 60 is defined relative to upper surfaces of the plurality of first elements, and a second plane 70 is defined relative to lower surfaces of the plurality of second elements, and wherein each upper surface of the plurality of first elements has a center portion 44 located in the first plane and an edge portion 46 below the first plane;

[0057] In a placing step 230, also referred to as step c), the blank is placed in a cutting device so that a portion of the lower outer surface faces the upper surfaces of the plurality of first elements and a portion of the upper outer surface faces the lower surfaces of the plurality of second elements;

[0058] In a moving step 240, also referred to as step d), the first die and the second die are moved relative to each other such that the first plane moves toward and through the second plane such that each of the plurality of first elements passes at least partially between adjacent elements of the plurality of second elements, and wherein teeth 80 of the cutting blade or guard are formed corresponding to the positions of the plurality of first elements, and wherein the teeth have a lower outer surface formed by a lower outer surface of the blank;

[0059] In utilization step 250, also referred to as step e), after step d), a bending device 30 is utilized to bend edge portions 82 of the teeth of the cutting blade or guard extending below the plane of the blank back toward the plane of the blank.

[0060] In one example, at least a portion of the upper outer surface is substantially planar.

[0061] In one example, a portion of the upper outer surface is substantially parallel to a portion of the lower outer surface.

[0062] In one example, a portion of the upper outer surface is angled with a portion of the lower outer surface.

[0063] Thus, a portion of the blank may be generally flat and planar, such that the teeth have a constant thickness along their length toward the end. However, a portion of the blank may have a generally flat bottom surface and a generally flat upper surface angled to the bottom, and therefore have a variable thickness, such that the teeth change their thickness along their length. However, the entire blank may be curved, but above a portion of the blank (e.g., covering a lateral region in which two or more teeth are formed) is as described above. Thus, in general, the blank may be curved or pre-bent, such as for a rotating razor cutter / guard. Importantly, when the blank is cut, the teeth are cut so that they have an edge on the bottom surface that protrudes below the surface in the direction in which the second die 50 moves. Therefore, for flat or curved blanks, this still applies as described above.

[0064] It should also be noted that the above method provides a process for forming the teeth of a cutting blade or guard, and likewise, there may be other process steps required to form the finished cutting blade or guard using steps before and / or after the above steps.

[0065] It should be noted that in one implementation, the above method does not need to form all teeth of the cutting blade or guard. For example, the method can be applied for the first time to cut a first plurality of teeth, and the method can be applied for the second time to cut a second plurality of teeth, and so on. In addition, the method can be applied for the first and more times using the same first and second molds. However, the method can be applied multiple times using different first and second molds to cut all teeth of the cutting blade or guard, but the same method steps as defined above are utilized using molds that meet the functional characteristics described above. Therefore, for example, multiple teeth in a trimmer guard can be cut using multiple cutting pieces, but only one cutting piece (mold pair) can be used, depending on the outer contour that needs to be cut. In other words, method steps a to d can be applied once or multiple times to cut different groups of teeth of the entire cutting piece / guard, and step e) can be applied once, or steps a to e can be applied once or multiple times to cut different groups of teeth of the entire cutting piece / guard. Therefore, in fact, the first and second molds described above can be considered as each single element, or composed of multiple elements. Therefore, the first and second molds can be a pair of elements for cutting teeth, or a group of multiple elements for cutting teeth.

[0066] In one example, step e) includes bending edge portions of the teeth of the cutting blade or guard using a rolling process.

[0067] According to one example, in step e), the bending device comprises a first plate 90 comprising a substantially planar upper surface 92. Then, the method comprises step f) bending 260 the edge portion of the teeth of the cutting blade or guard by pushing the planar upper surface of the first plate against the lower outer surface of the teeth.

[0068] In examples, the second plate interacts with the upper outer surface of the tooth, while the first plate is pushed against the lower outer surface of the tooth.

[0069] According to an example, the first die and the second die of the cutting device are configured so that in step d), when each element of the plurality of first elements passes at least partially between adjacent elements of the plurality of second elements, an element of the plurality of first elements is laterally spaced from an element of the plurality of second elements by a distance 100 that is less than or equal to 15% of a thickness 110 of the blank. The thickness of the blank is equal to the distance between a portion of the upper outer surface and a portion of the lower outer surface.

[0070] In an example, when each element of the plurality of first elements passes at least partially between adjacent elements of the plurality of second elements, elements of the plurality of first elements are laterally spaced apart from elements of the plurality of second elements by a distance 100 that is less than or equal to 13% of a thickness 110 of the blank,

[0071] In a particularly preferred example, when each element of the plurality of first elements passes at least partially between adjacent elements of the plurality of second elements, elements of the plurality of first elements are laterally spaced apart from elements of the plurality of second elements by a distance 100 that is less than or equal to 10% of a thickness 110 of the blank,

[0072] In an example, when each element of the plurality of first elements passes at least partially between adjacent elements of the plurality of second elements, elements of the plurality of first elements are laterally spaced from elements of the plurality of second elements by a distance 100 that is less than or equal to 8% of a thickness 110 of the blank,

[0073] In an example, when each of the plurality of first elements passes at least partially between adjacent elements of the plurality of second elements, elements of the plurality of first elements are laterally spaced from elements of the plurality of second elements by a distance 100 that is less than or equal to 6% of a thickness 110 of the blank.

[0074] According to an example, each element of the plurality of first elements comprises a curved upper surface 47 .

[0075] According to an example, each element of the first plurality of elements has a cut corner 48 .

[0076] In an example, the outer edge of the chamfer is below the first plane by a distance 120 that is greater than 6% of the thickness of the blank.

[0077] According to an example, the bending device comprises a second plate 130 comprising a plurality of recesses 140. The depth 150 of each recess is less than the thickness of the blank, wherein the thickness of the blank is equal to the distance between a portion of the upper outer surface and a portion of the lower outer surface. In step f), the bending of the edge portion of the teeth of the cutting blade or guard comprises placing the teeth in the plurality of recesses and moving the first plate and the second plate towards each other.

[0078] According to an example, the openings in the plurality of recesses are located in the lower surface 160 of the second plate. The width 170 of each opening at the lower surface is wider than the width of each cutting tooth. In step f), the lower surface of the second plate faces the upper surface of the first plate.

[0079] According to an example, each bottom of the plurality of recesses has a flat portion having a width less than the width of each cutting tooth, and has rounded corners on either side of the recess, the rounded corners extending from the flat portion to side portions on either side of the recess, the side portions being spaced apart from each other at a distance greater than the width of each cutting tooth.

[0080] Therefore, according to Figure 1 The method described allows for the manufacture of a cutting blade or guard having teeth formed from a blank of material.

[0081] According to the method described above, and according to Figures 2 to 10, one example relates to a cutting and bending system for forming a plurality of teeth of a cutting blade or guard. The cutting and bending system includes a cutting device 20 and a bending device 30. The cutting device includes a first die 40 and a second die 50. The first die includes a plurality of first elements 42, and the second die includes a plurality of second elements 52. A first plane 60 is defined relative to the upper surface of the plurality of first elements, and a second plane 70 is defined relative to the lower surface of the plurality of second elements. Each upper surface of the plurality of first elements has a center portion 44 located in the first plane and an edge portion 46 below the first plane. The cutting device is configured so that a blank of material can be placed in the cutting device. The blank includes an upper outer surface and a lower outer surface. At least a portion of the lower outer surface is substantially planar and forms a plane of the blank. When the blank is placed in the cutting device, a portion of the lower outer surface faces the upper surface of the plurality of first elements, and a portion of the upper outer surface faces the lower surface of the plurality of second elements. The first die and the second die of the cutting device are configured to move relative to each other so that the first plane moves toward and through the second plane. In this way, each of the plurality of first elements passes at least partially between adjacent elements of the plurality of second elements. When the blank is placed in the cutting device and cut by the cutting device, teeth 80 of the cutting blade or guard are formed corresponding to the positions of the plurality of first elements. The teeth have a lower outer surface formed by the lower outer surface of the blank. The cutting device is configured so that when the blank has been cut by the cutting device, an edge portion 82 of the teeth of the cutting blade or guard extends below the plane of the blank. The bending device is configured to bend the edge portion of the teeth of the cutting blade or guard back toward the plane of the blank after cutting, and the edge portion extends below the plane of the blank.

[0082] In one example, at least a portion of the upper outer surface is substantially planar.

[0083] In one example, a portion of the upper outer surface is substantially parallel to a portion of the lower outer surface.

[0084] In one example, a portion of the upper outer surface is angled with a portion of the lower outer surface.

[0085] According to an example, the bending device comprises a first plate 90 comprising a substantially planar upper surface 92. The bending device is configured to bend an edge portion of a tooth of a cutting blade or guard. The device performs the bending by pushing the planar upper surface of the first plate against the lower outer surface of the tooth.

[0086] According to an example, the first die and the second die of the cutting device are configured such that when each element of the plurality of first elements passes at least partially between adjacent elements of the plurality of second elements, an element of the plurality of first elements is laterally spaced from an element of the plurality of second elements by a distance 100 that is less than or equal to 10% of a thickness 110 of the blank. The thickness of the blank is equal to a distance between a portion of the upper outer surface and a portion of the lower outer surface.

[0087] In an example, when each of the plurality of first elements passes at least partially between adjacent elements of the plurality of second elements, elements of the plurality of first elements are laterally spaced from elements of the plurality of second elements by a distance 100 that is less than or equal to 8% of a thickness 110 of the blank.

[0088] In an example, when each of the plurality of first elements passes at least partially between adjacent elements of the plurality of second elements, elements of the plurality of first elements are laterally spaced from elements of the plurality of second elements by a distance 100 that is less than or equal to 6% of a thickness 110 of the blank.

[0089] In the example, each element of the first plurality of elements comprises a curved upper surface 47 .

[0090] According to an example, each element of the first plurality of elements has a cut corner 48 .

[0091] In an example, the cut corner has an angle of approximately 45 degrees.

[0092] In an example, the cut corner has an angle of approximately 40 degrees.

[0093] In an example, the cut corner has an angle of approximately 30 degrees.

[0094] In an example, the cut corner has an angle of approximately 25 degrees.

[0095] In an example, the cut corner has an angle of approximately 20 degrees.

[0096] According to an example, the outer edge of the chamfer is located below the first plane at a distance greater than 6% of the thickness of the blank, wherein the thickness of the blank is equal to the distance between a portion of the upper outer surface and a portion of the lower outer surface.

[0097] According to an example, the bending device includes a second plate 130, which includes a plurality of recesses 140. The depth 150 of each recess is less than the thickness of the blank, wherein the thickness of the blank is equal to the distance between a portion of the upper outer surface and a portion of the lower outer surface. The second plate is configured so that the teeth of the cutting blade or guard can be located in the plurality of recesses. Each tooth can be located in a separate recess. The bending device is configured to bend the edge portion of the teeth of the cutting blade or guard, including movement of the first plate and the second plate toward each other.

[0098] According to an example, the openings in the plurality of recesses are located in the lower surface 160 of the second plate. The width 170 of each opening at the lower surface is wider than the width 84 of each cutting tooth. The lower surface of the second plate faces the upper surface of the first plate.

[0099] According to one example, each bottom of the plurality of recesses has a flat portion whose width 180 is smaller than the width 84 of each cutting tooth, and has rounded corners 190 on both sides of the recess extending from the flat portion to side portions on both sides of the recess, and the side portions are spaced apart from each other by a distance 170 greater than the width of each cutting tooth.

[0100] Therefore, the method for forming a plurality of teeth of a cutting blade or guard as described above, a cutting blade or guard with a plurality of teeth formed by the method, and a cutting and bending system for forming a plurality of teeth of a cutting blade or guard have advantages. Traditional stamping causes a cutting edge angle greater than 90 °, while forging causes a blunt cutting edge due to the work hardening of steel, and etching is complicated and expensive. The new tooth forming method described herein causes a cutting edge angle less than 90 ° and a sharp cutting edge tip (tip radius can be less than 2 μm). At the same time, the manufacturing technology is not expensive because only metal forming technology is required and finishing technology is not required.

[0101] This new method, by creating the edge of the material in a first cutting step using, for example, a chamfered die plate, and then pushing the edge back (by force) in a second coining / bending step, is applicable to all types of linear cutting elements, such as used in shavers and trimmers, and can also work for rotary cutting systems. Thus, the new two-step cold forming process or method enables guards and teeth of cutting blades with sharp edges to be manufactured in a cost-effective manner.

[0102] Reference Figures 2 to 10 , a method of forming multiple teeth of a cutting blade or guard, a cutting blade or guard having multiple teeth formed by the method, and a cutting and bending system for forming multiple teeth of a cutting blade or guard will now be described in more detail with respect to detailed specific examples.

[0103] Figure 2 On the left is shown a blank of material (such as steel) which is cut to form teeth or lamellae 80 so as to form excess material or edge portions 82 at the edges of the cuts. A first die (or cutting plate) 40 has a plurality of cutting elements 42 and a second die (or punch) 50 has a plurality of cutting elements 52. The center portion 44 of the cutting elements 42 of the first die 40 is above or raised above the edges and in this example, the cutting elements 42 have curved surfaces 47. In this way, when the blank is cut to form the teeth 80, each tooth has an edge portion 82 protruding downwardly, as shown in FIG. Figure 3 The teeth or sheet is shown above the cutting plate or element of the first die, while the scrap has been cut and is shown below the punch element of the second die. To help achieve this, the second die may have a Figure 2 The blank holder is shown lowered onto the teeth. However, the cutting process using the cutting elements of the first and second dies to produce teeth 80 of the correct form does not require a blank holder. It is necessary that the cutting elements 42 of the first die 40 have an edge 46 below the center of each cutting element 42. Back Figure 3 , the top image schematically shows Figure 2 The freshly cut tooth 80 is shown in FIG. Figure 3 In the bottom image of , the tooth 80 is shown after the edge portion 82 has been bent upward. Note that this is the cutting step of the forming process, and the tooth will be bent as discussed in detail below.

[0104] Figure 4-Figure 5 Examples of different detailed mechanisms for cutting and bending a blank material to form teeth 80 of a cutting blade or guard are shown. After the cutting process using the cutting device 20, a bending process using the bending device 30 is performed to form a plurality of teeth 80. Figure 4 In FIG. 4 , a blank material is placed on the cutting element 42 of the first die 40, and the cutting element 52 of the second die 50 is shown. The cutting element 42 again has a center 44 that is higher than an edge 46, which in this example is a cutting corner 48. A first plane 60 is formed relative to the center 44 of the cutting element 42 of the first die 40. A second plane 70 is formed relative to the lower surface of the cutting element 52 of the second die 50. As shown in FIG. Figure 5 As shown in the left-hand image of , the blank is cut by moving the first die toward the second die, or the second die toward the first die, or the first die and the second die relative to each other, so that the first plane 60 and the second plane 70 intersect each other, as shown in FIG. Figure 6 In this manner, the teeth 80 of the cutting blade or guard are cut, the teeth 80 having edge portions 82 extending below the bottom surface of the teeth. Figure 5As shown in the left-hand image of FIG. 5 , the discarded portion of the blank is shown below the cutting element 52 of the second die 50, which has been "cut away". Figure 5 As shown in the right-hand image of , the cut teeth 80 will then be bent to form the teeth of a guard or cutting blade of a shaver or trimmer. The teeth 80 are positioned within a recess 140 of a plate 130. The depth 150 of the recess is less than the thickness of the blank. The bottom of the recess has a rounded corner 190, and the width 180 of the bottom of the recess is less than the width of the tooth. However, the opening of the recess has a width 170 that is wider than the width 84 of the tooth at its lower surface. The upper surface 92 of the plate 90 is then pushed up against the teeth 80, and the downwardly protruding edge portion 82 is bent upward and forms a sharp and strong cutting edge. This configuration helps to bend the edge portion 82 upward, but the top plate can be just a flat plate, just like the bottom plate, and does not need to have a recess.

[0105] As mentioned above, Figure 6 Again the blank is shown being cut by the first die and the second die, and Figure 7 An image of a portion of the first mold 40 is shown, showing the cutting element 42. Figure 6 In FIG. 1 , a rectangle bisecting the first die 40 and its cutting element 42 is shown and is actually Figure 7 The hole shown is where the element 52 of the second die 50 will move during cutting. Figure 7 In the image of FIG. 4 , a portion of the top surface of the two elements 42 of the first mold 40 is shown, and the second mold 50 is not shown, but the elements 52 of the second mold will move downward and pass within the notches (or holes) shown.

[0106] The molds 40, 50 may be manufactured using known techniques.

[0107] Figure 8 Further details of the first die 40 and its cutting elements 42 and the second die 50 and its cutting elements 52 are shown. When the cutting elements pass through each other, a gap (d) 100 is provided between the cutting elements, which in this detailed example is 6% or less of the thickness (t) 110 of the blank. The gap may be larger than this gap, for example, in the order of 10% or less of the thickness of the blank. Figure 5 , Figure 6 and Figure 8As shown, when the blank is cut, the top portion of each tooth can be wider than the bottom portion having edge 82 (edge ​​82 extends below the bottom surface of the tooth). During the bending process, these edges are bent back toward the bottom plane or surface of the tooth, and the final width of the bottom surface, which now has a sharp cutting edge, can be wider than the top portion of the tooth or narrower than the top portion of the tooth (due to the top portion of the tooth having been flared outward during the cutting process). In fact, the second die 50 can have chamfered edges of its cutting elements 52 in order to produce a tooth with a correctly sized profile through its thickness. This is in Fig. 9 and Fig.10 This is shown in more detail in FIG, where an image of the final teeth of the cutting blade and guard are shown.

[0108] Then, Fig. 9 The top image shows teeth formed by the cutting and bending process described herein for a guard having a thickness of 0.11 mm, and the middle image shows teeth formed by the cutting and bending process described herein for a guard having a thickness of 0.3 mm. The bottom image shows teeth formed by the cutting and bending process described herein.

[0109] like Fig.10 As shown, the teeth have sharp edges, where the portion of the edge that previously protruded downward from the cutting step has then been bent back upward during the bending step. However, the sharp edge is part of a global area (indicated by the arrow) that is slightly lower than the entire bottom of the tooth, because this portion of the material will not normally be bent completely back into the plane of the bottom of the tooth. This is shown in FIG. Figure 9-10 In the cross section through the teeth shown and in Fig.10 This is clearly shown in the plan view of FIG. 1 , where the bent edge portions are clearly visible because they are not bent exactly back into the bottom plane. Figure 9-10 As shown, depending on the deformation of the tooth during the cutting and / or bending process, the body of the formed tooth can be wider than the cutting edge, or vice versa.

[0110] It should be noted that embodiments of the present invention are described with reference to different subject matters. Specifically, some embodiments are described with reference to method type claims, while other embodiments are described with reference to device type claims. However, a person skilled in the art will deduce from the above and following descriptions that, unless otherwise notified, any combination of features related to different subject matters, in addition to any combination of features belonging to one type of subject matter, is also considered to be disclosed by the present application. However, all features may be combined to provide a synergistic effect, rather than just a simple sum of these features.

[0111] Although the present invention has been illustrated and described in detail in the drawings and the foregoing description, such illustration and description are to be considered illustrative or exemplary rather than restrictive. The present invention is not limited to the disclosed embodiments. Other variations of the disclosed embodiments may be understood and effected by those skilled in the art in practicing the claimed invention by studying the drawings, the disclosure, and the dependent claims.

[0112] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. A method (200) of forming a plurality of teeth of a cutting blade or guard, the method comprising: a) obtaining (210) a billet of material, the billet having an upper outer surface and a lower outer surface, wherein at least a portion of the lower outer surface is substantially planar and forms a plane of the billet; b) utilizing (220) a cutting apparatus (20) comprising a first die (40) and a second die (50), wherein the first die comprises a plurality of first elements (42), and the second die comprises a plurality of second elements (52), wherein a first plane (60) is defined relative to upper surfaces of the plurality of first elements, and a second plane (70) is defined relative to lower surfaces of the plurality of second elements, wherein each upper surface of the plurality of first elements has a central portion (44) and an edge portion (46), the central portion (44) being located in the first plane, and the edge portion (46) being below the first plane; c) placing (230) the blank in the cutting device so that a portion of the lower outer surface faces the upper surfaces of the plurality of first elements and a portion of the upper outer surface faces the lower surfaces of the plurality of second elements; d) moving the first die and the second die relative to each other (240) such that the first plane moves toward and through the second plane such that each of the plurality of first elements passes at least partially between adjacent elements of the plurality of second elements, and wherein teeth (80) of the cutting blade or guard are formed corresponding to the positions of the plurality of first elements, and wherein the teeth have a lower outer surface formed by the lower outer surface of the blank; as well as e) After step d), utilizing (250) a bending device (30) to bend edge portions (82) of the teeth of the cutting blade or guard extending below the plane of the blank back toward the plane of the blank.

2. A method according to claim 1, wherein in step e), the bending device includes a first plate (90), the first plate (90) includes a substantially planar upper surface (92); and wherein the method includes step f): bending (260) the edge portion of the tooth of the cutting blade or guard by pushing the planar upper surface of the first plate against the lower outer surface of the tooth.

3. The method according to any one of claims 1 to 2, wherein: The first die and the second die of the cutting device are configured such that: in step d), when each of the plurality of first elements passes at least partially between adjacent elements of the plurality of second elements, the elements of the plurality of first elements are laterally spaced apart from the elements of the plurality of second elements by a distance (100), the distance (100) being less than or equal to 15% of the thickness (110) of the blank, wherein the thickness of the blank is equal to the distance between the portion of the upper outer surface and the portion of the lower outer surface.

4. The method according to claim 3, wherein the distance (100) is less than or equal to 10% of the thickness (110) of the blank.

5. The method according to any one of claims 1 to 2, wherein each element of the plurality of first elements comprises a curved upper surface (47).

6. The method according to any one of claims 1 to 2, wherein each element of the plurality of first elements has a chamfer angle (48), the chamfer angle (48) being in the range of 20 to 45 degrees.

7. The method of claim 6, wherein the chamfer angle (48) is in the range of 25 to 30 degrees.

8. The method of claim 2, wherein the bending apparatus comprises a second plate (130), the second plate (130) comprising a plurality of recesses (140), wherein a depth (150) of each recess is less than a thickness of the blank, wherein the thickness of the blank is equal to a distance between the portion of the upper outer surface and the portion of the lower outer surface; and Wherein in step f), the bending of the edge portion of the teeth of the cutting blade or guard comprises positioning the teeth within the plurality of recesses and moving the first plate and the second plate toward each other.

9. A method according to claim 8, wherein the openings of the plurality of recesses are located in the lower surface (160) of the second plate, wherein the width (170) of each opening at the lower surface is wider than the width of each cutting tooth, and wherein in step f), the lower surface of the second plate faces the upper surface of the first plate.

10. The method according to any one of claims 8 to 9, wherein each bottom of the plurality of recesses has a flat portion and has rounded corners on both sides of the recess, the width of the flat portion being smaller than the width of each cutting tooth, and the rounded corners extending from the flat portion to side portions on both sides of the recess, the side portions being spaced apart from each other by a distance greater than the width of each cutting tooth.

11. A cutting and bending system (10) for forming a plurality of teeth of a cutting blade or guard, the cutting and bending system comprising: Cutting equipment (20); and Bending device (30); wherein the cutting apparatus comprises a first die (40) and a second die (50), wherein the first die comprises a plurality of first elements (42), and the second die comprises a plurality of second elements (52), wherein a first plane (60) is defined relative to upper surfaces of the plurality of first elements, and a second plane (70) is defined relative to lower surfaces of the plurality of second elements, and wherein each upper surface of the plurality of first elements has a central portion (44) located in the first plane and an edge portion (46) below the first plane; wherein the cutting apparatus is configured such that a blank of material can be placed in the cutting apparatus, wherein the blank comprises an upper outer surface and a lower outer surface, wherein at least a portion of the lower outer surface is substantially planar and forms a plane of the blank; and wherein when the blank is placed in the cutting apparatus, a portion of the lower outer surface faces the upper surfaces of the plurality of first elements and a portion of the upper outer surface faces the lower surfaces of the plurality of second elements; wherein the first die and the second die of the cutting apparatus are configured to move relative to each other so that the first plane moves toward and through the second plane so that each of the plurality of first elements passes at least partially between adjacent elements of the plurality of second elements, and wherein teeth (80) of the cutting blade or guard are formed corresponding to positions of the plurality of first elements when the blank is placed in and cut by the cutting apparatus, and wherein the teeth have a lower outer surface formed by the lower outer surface of the blank; wherein edge portions (82) of the teeth of the cutting blade or guard extend below the plane of the blank when the blank has been cut by the cutting device; and wherein the bending device is configured to, after cutting, bend the edge portions of the teeth of the cutting blade or guard extending below the plane of the blank back towards the plane of the blank; Wherein at least a portion of the upper outer surface is substantially planar.

12. A cutting and bending system according to claim 11, wherein the bending device includes a first plate (90), the first plate (90) includes a substantially planar upper surface (92), and wherein the bending device is configured to bend the edge portion of the tooth of the cutting blade or guard, which includes the planar upper surface of the first plate being pushed against the lower outer surface of the tooth.

13. A cutting and bending system according to any one of claims 11 to 12, wherein the first mold and the second mold of the cutting device are configured such that when each of the plurality of first elements passes at least partially between adjacent elements of the plurality of second elements, the elements of the plurality of first elements are laterally spaced apart from the elements of the plurality of second elements by a distance (100), and the distance (100) is less than or equal to 10% of the thickness (110) of the blank, wherein the thickness of the blank is equal to the distance between the portion of the upper outer surface and the portion of the lower outer surface.

14. The cutting and bending system according to any one of claims 11 to 12, wherein each element of the plurality of first elements has a cutting angle (48), the cutting angle (48) being in the range of 20 to 45 degrees.

15. The cutting and bending system of claim 14, wherein the cutting angle (48) is in the range of 25 to 30 degrees.

16. A cutting and bending system according to claim 14, wherein the outer edge of the cut angle is located below the first plane (120) at a distance greater than 6% of the thickness of the blank, wherein the thickness of the blank is equal to the distance between the portion of the upper outer surface and the portion of the lower outer surface.

17. A cutting and bending system according to claim 12, wherein the bending device includes a second plate (130), the second plate includes a plurality of recesses (140), wherein the depth (150) of each recess is less than the thickness of the blank, wherein the thickness of the blank is equal to the distance between the portion of the upper outer surface and the portion of the lower outer surface; and wherein the second plate is configured so that the teeth of the cutting blade or guard can be positioned within the plurality of recesses, wherein each tooth is positioned in a separate recess, and wherein the bending device is configured to bend the edge portion of the teeth of the cutting blade or guard, which includes moving the first plate and the second plate toward each other.

Images