Nail file

Abstract

To provide a nail file that is easy for handling and that can precisely file nails down to the last detail.SOLUTION: A nail file is composed of a roughly square plate-like member 1 which has a front face 2 and a rear face 3 and which has four sides 4a-4d composed of relative two sets of two sides and has four corner parts 5a-5d. Each of the four sides 4a-4d is designed to be a curve bulging toward outer side of the roughly squares in the inner sides rather than both ends of each side, with four corner parts 5a-5d made obtuse angles. Further, on the inner sides surrounded by the four sides 4a-4d of the plate-like member 1, there are formed finger holes 6 penetrating the front face 2 and the rear face 3. Also, along the sides 4a, 4c in the front face 2 and the rear face 3, and in a manner that includes the four corner parts 5a-5d, there is formed a file part 7.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] TECHNICAL FIELD The present disclosure relates to nail files. [Background technology]

[0002] Conventionally, nail files have been configured with a grip portion disposed at one end of a long, plate-shaped main body on which a file portion is formed (see, for example, Patent Document 1). When using the nail, a user holds the grip portion in their hand and grinds the nail by pressing the file portion against the nail or pressing the nail against the file portion. The long, plate-shaped main body is a flat plate or a curved plate formed by bending a flat plate, and has a structure in which the file portion is provided on the surface side. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 7-30905 Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional nail files have a structure in which a grip part is disposed at one end of a long plate-shaped main body, so the file part and the grip part are thin and difficult to grip. This makes it difficult to handle when in use, and the file part is easily removed from the nail, making it difficult to file the nail accurately. In addition, it is difficult to file the lateral nail plate edge at both ends of the nail, that is, the nail near the boundary with the skin, with the part of the file part located on the long side of the main body. Even if a file part is provided at the tip of the main body, the nail is filed with the tip away from the grip, and in addition, the tip is sharp, so the file part hits and gets caught on the flesh around the nail, making it difficult to file the nail accurately down to the fine details.

[0005] An object of the present disclosure is to provide a nail file that is easy to handle and capable of accurately filing even the finest details of a nail. [Means for solving the problem]

[0006] In order to achieve the above object, the nail file described in claim 1 is composed of a plate-like member (1) having a surface (2) and a back surface (3) opposite the surface, four sides (4a-4d) formed by two pairs of opposing sides, and four corners (5a-5d) formed by the four sides. A finger insertion hole (6) penetrating the surface and back surface is formed inside the plate-like member surrounded by the four sides, and file portions (7, 7a-7d) are formed on at least one of the surface and back surfaces along each of two sides of one pair of opposing sides and including the four corners.

[0007] By making such a nail file, it is possible to give it a wide outer shape, making it easy to handle when in use, and making it difficult for the file part to come off the nail when using it to grind the nail. Also, since it has a finger insertion hole, if you insert part of your finger into the finger insertion hole and hold the nail file with your finger in contact with the inner wall of the finger insertion hole, you can grip it and hold the nail file more stably. Therefore, it is possible to make a nail file that is easy to handle and can accurately file even the smallest details of the nail.

[0008] In the invention described in claim 2, each of the four corners is rounded. By rounding the four corners in this way, it is possible to prevent the corners from catching on the skin when filing the nail with the file, and it is possible to make the sensation of the four corners hitting the skin softer than when they are sharp.

[0009] In the inventions described in claims 3 and 5, the four corners are obtuse angles. In this way, if the four corners are obtuse angles, the four corners with obtuse angles can also be provided with file parts on at least one of the front and back surfaces. Therefore, by using the file parts on the corners, fine areas such as the outer edge of the nail including the lateral nail plate edge can be well ground, and the problem of the file part hitting the flesh of the finger can be eliminated. In addition, if the four corners are right angles or acute angles, the file area of ​​the corners is reduced, making it easy for the nail to slip off the file part and making it difficult to file the nail evenly over a wide area. However, since the four corners are obtuse angles, the file area of ​​the corners can be made large, making it possible to file the nail evenly over a wide area while filing the fine details. Therefore, a nail file can be made that is easy to handle and can accurately file even the fine details of the nail.

[0010] For example, as described in claim 4, each of the four sides can be curved such that the distance between the two opposing sides is wider on the inside than at both ends of each side. In that case, as described in claim 6, each of the four sides can be rounded and the four corners can also be rounded, with the radius of curvature of the rounded shapes of the four corners being smaller than the radius of curvature of the rounded shapes of the four sides, and each of the four corners can be configured such that the angles at which the tangents intersect at both ends of the rounded portion of each corner are obtuse angles.

[0011] In the invention described in claim 7, the plate-shaped member has two opposing pairs of two sides (4a, 4c) of one pair that are symmetrical about a first line (L1) passing through the center (O) of the plate-shaped member, and the other pair of two sides is symmetrical about a second line (L2) that passes through the center and is perpendicular to the first line, and the front surface is curved such that it bulges as it approaches the second line from the other pair of two sides, and the back surface is curved such that it bulges as it approaches the second line from the other pair of two sides, and the back surface is curved such that it bulges as it approaches the second line from the other pair of two sides.

[0012] In this way, by warping the nail file into a curved shape, the file surface of the file portion can be curved to accommodate various nail shapes.

[0013] In the invention described in claim 8, one set of two sides of the plate-like member is longer than the other set of two sides, the direction along the first line is the long side and the direction along the second line is the short side, and the finger insertion hole is elliptical in shape with the long axis along the first line and the short axis along the second line.

[0014] In this way, by making the finger hole into an oval shape without any corners, the load on the fingers can be evenly distributed evenly, even when the nail file is held in such a way that force is applied to the inner peripheral wall of the finger hole.

[0015] In the invention described in claim 9, the file portions are formed on both the front and back surfaces, and the file portion formed on the front surface is configured to have a first file portion (7a) formed along one of the two sides of one set and a second file portion (7b) formed along the other of the two sides of the one set, and the file portion formed on the back surface is configured to have a third file portion (7c) formed along one of the two sides of the one set and opposite the first file portion, and a fourth file portion (7d) formed along the other of the two sides of the one set and opposite the second file portion.

[0016] In this way, the file parts are provided on different curved surfaces, the front surface being a convex surface and the back surface being a concave surface, so different types of file parts can be provided on the front side and the back side. Therefore, by using different types of file parts depending on the part of the nail you want to file, you can file the nail more precisely.

[0017] In the invention described in claim 10, the first file portion and the second file portion have different roughnesses, and the third file portion and the fourth file portion have different roughnesses. In this way, when two file portions with different roughnesses are provided on both the front and back surfaces, two file portions with different roughnesses can be configured on each of the front surface, which is a convex surface, and the back surface, which is a concave surface, and a total of four file portions with different roughnesses can be configured on the front and back surfaces. Therefore, the four types of file portions can be used to file nails more finely.

[0018] There are also four different types of files, with two different combinations of coarse and fine surfaces, and two different textured surfaces, and the corners can also be used, meaning a total of five different types of files can be used in different ways. All of these files are compact, thin, and do not require a handle. This means that you can care for your nails with just this one file, without having to prepare multiple types of files. For example, it is compact and easy to carry in a makeup pouch.

[0019] In the invention described in claim 11, the first file portion and the third file portion have the same roughness, and the second file portion and the fourth file portion have the same roughness. By making the roughness of the file portions located on the same side on the front and back the same, whether the nail is filed on the front or back, the user can recognize that the file portion with the same roughness is on the same side and file the nail. Therefore, when turning the nail file over to file, the user can easily file the nail without checking the roughness of the file portion.

[0020] Note that the reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and specific components described in the embodiments described below. [Brief description of the drawings]

[0021] [Figure 1] 1A, 1B, and 1C are diagrams showing a nail file according to a first embodiment of the present disclosure, in which (a) is a front view, (b) is a right side view of (a), and (c) is a rear view. [Diagram 2] FIG. 2 is a perspective view of the nail file shown in FIG. 1(a) as viewed from diagonally front right. [Diagram 3] FIG. 1 is a diagram illustrating how to use a nail file. [Figure 4] FIG. 1 is a diagram illustrating how to use a nail file. [Diagram 5] FIG. 1 is a diagram illustrating how to use a nail file. [Figure 6] This is a diagram showing a nail file and a sword tsuba stacked on top of each other. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following, including other embodiments described below, the same reference numerals will be used to denote the same or equivalent parts in each embodiment.

[0023] (First embodiment) Hereinafter, a nail file 1 according to a first embodiment of the present disclosure will be described with reference to Figs. 1 to 5.

[0024] [Nail file configuration] The nail file shown in Figs. 1 and 2 is held by a user and is used to grind the nails of fingers and toes.

[0025] In addition, the drawings attached to this specification show the X-axis, Y-axis, and Z-axis. As shown in Fig. 1, the up-down direction when the nail file is viewed from the front is called the X-axis, the left-right direction of the nail file perpendicular to the X-axis is called the Y-axis, and the thickness direction of the nail file perpendicular to the X-axis and Y-axis is called the Z-axis. In addition, the side of the nail file shown in Fig. 1(a) is called the front side, and the side shown in Fig. 1(c) is called the back side.

[0026] As shown in Fig. 1(a) to (c), the nail file is composed of a curved metal plate-shaped member 1. The plate-shaped member 1 has a front surface 2, which is one surface on the front side, as shown in Fig. 1(a), and a back surface 3, which is the opposite surface of the front surface 2 and is one surface on the back side, as shown in Fig. 1(c). When viewed from the front, the plate-shaped member 1 is composed of an approximately quadrangle having four sides 4a to 4d formed by two pairs of opposing sides and four corners 5a to 5d formed by the four sides 4a to 4d. Note that the approximately quadrangle shape here means a shape in which the corners 5a to 5d are formed between adjacent sides of each of the sides 4a to 4d, and each of the sides 4a to 4d does not have to be a straight line, and the corners 5a to 5d do not have to be corners where straight lines intersect each other.

[0027] Specifically, of the four sides 4a to 4d, the two opposing sides 4a, 4c of one set extending in the X-axis direction are longer than the two opposing sides 4b, 4d of the other set extending in the Y-axis direction. Therefore, the plate-like member 1 is a flattened, approximately quadrilateral shape in which the two sides 4a, 4c are longer than the two sides 4b, 4d. In addition, the two sides 4a, 4c are both curved, and the two sides 4a, 4c are curved such that the inner sides of the two sides 4a, 4c bulge toward the outside of the approximately quadrangle, that is, along the Y-axis direction. Similarly, the two sides 4b, 4d are both curved, and the two sides 4b, 4d are curved such that the inner sides of the two sides 4b, 4d bulge toward the outside of the approximately quadrangle, that is, along the X-axis direction. In other words, the two opposing sides 4a, 4c and the two opposing sides 4b, 4d are curved such that the distance between the two opposing sides is wider on the inner side than on both sides.

[0028] Here, a straight line parallel to the X-axis direction passing through the center O of the approximately rectangular shape formed by the plate-like member 1 is defined as a first straight line L1, and a straight line parallel to the Y-axis direction passing through the center O is defined as a second straight line L2. The two sides 4a and 4c are symmetrical with respect to the first straight line L1, and the intersections with the second straight line L2 are defined as points Pa and Pc, respectively. As the points Pa and Pc approach the sides 4b and 4d, the shortest distance from the first straight line L1 gradually approaches the curve. In the case of this embodiment, the two sides 4a and 4c are curved with a different radius of curvature between the inner part intersecting with the second straight line L2 and both ends connected to the corners 5a to 5d on both sides, for example, and are curved in an R shape with a radius of curvature of 80.0 mm for the inner part and a radius of curvature of 100 mm for both ends, that is, a circular arc-shaped curve.

[0029] On the other hand, the two sides 4b and 4d are also symmetrical with respect to the second straight line L2, and are curved such that the intersections with the first straight line L1 are points Pb and Pd, respectively, and the shortest distance between the two sides and the second straight line L2 gradually decreases as the points Pb and Pd approach the sides 4a and 4c. In this embodiment, the two sides 4b and 4d are rounded with a radius of curvature of, for example, 41.5 mm.

[0030] Since the two sides 4a and 4c are longer than the two sides 4b and 4d, the dimension from point Pb where the first straight line L1 intersects with the two sides 4b and 4d to point Pd is greater than the dimension from point Pa where the second straight line L2 intersects with the two sides 4a and 4c to point Pc. That is, the plate-shaped member 1 is substantially rectangular in shape with the X-axis direction along the first straight line L1 as the longitudinal direction and the Y-axis direction along the second straight line L2 as the transverse direction. For example, the plate-shaped member 1 has a longitudinal dimension of 55.0 mm and a transverse dimension of 40.0 mm at a position passing through the center O. The plate-shaped member 1 also has a constant thickness of 0.8 mm.

[0031] The four corners 5a to 5d are formed between adjacent sides of each of the sides 4a to 4d, and are rounded by being formed of a curved line with a larger curvature than each of the sides 4a to 4d. Each of the corners 5a to 5d is R-shaped and has a constant curvature larger than the curvature of the R-shape of each of the sides 4a to 4d. In the present embodiment, each of the corners 5a to 5d is R-shaped with a curvature radius of 3.25 mm, that is, a circular arc shape. Here, each of the corners 5a to 5d is formed with a R-shape with a constant curvature, but the curvature does not necessarily have to be constant. For example, the curvature may be different between the boundary position between each of the corners 5a to 5d and the part inside the boundary position. The same applies to the sides 4b and 4d, and the curvature radius may be different between the inner part intersecting with the first straight line L1 and both ends connected to each of the corners 5a to 5d on both sides. Conversely, the sides 4a and 4c may have a constant curvature.

[0032] In addition, since each of the sides 4a to 4d is curved and bulges outward, each of the corners 5a to 5d is an obtuse angle rather than an acute angle.

[0033] Here, the angle of a polygon including a quadrangle is generally the angle formed by two adjacent sides constituting a corner. In this embodiment, the angle of each corner 5a to 5d means the angle formed by two adjacent sides constituting each corner 5a to 5d, but is indicated by the angle formed by tangent lines drawn at the boundary positions of the two adjacent sides and each corner 5a to 5d. Each corner 5a to 5d may be formed by directly intersecting the two adjacent sides, or may be formed in an R-shape with a larger curvature than each side 4a to 4d as in this embodiment. Even if each corner 5a to 5d is R-shaped, if the angle at which the tangent lines drawn at the boundary positions of the two adjacent sides and each corner 5a to 5d intersect is an obtuse angle, it can be said that each corner 5a to 5d is formed at an obtuse angle. In this case, the contour of each of the corners 5a to 5d is positioned closer to the center O than a tangent line drawn at the boundary between each of the two adjacent sides and each of the corners 5a to 5d.

[0034] In addition, the plate-like member 1 has a finger hole 6 penetrating the front surface 2 and the back surface 3 inside the area surrounded by the four sides 4a-4b. The finger hole 6 is elliptical with the major axis along the first straight line L1 and the minor axis along the second straight line L2. For example, the major axis of the finger hole 6 is 36 mm, and the minor axis is 17 mm. The ratio of the major axis to the minor axis of the finger hole 6, that is, the ellipticity, is set according to the curvature of the two sides 4a, 4c located on both sides of the finger hole 6, and the contour of the ellipse is made close to the shape of the two sides 4a, 4c. Therefore, the width of the portion of the plate-like member 1 located between the two sides 4a, 4b and the finger hole 6 gradually increases as it moves away from the second straight line L2, but is almost the same width.

[0035] The outer surface of plate-shaped member 1 and the inner wall surface of finger hole 6 are rounded in the Z-axis direction, which is the thickness direction of plate-shaped member 1, making the nail file easier to hold and providing end faces that provide a soft feel when held. Also, the inner wall surface of finger hole 6 may be straight in the Z-axis direction without being rounded.

[0036] Furthermore, as shown in FIG. 1(b) and FIG. 2, the plate-shaped member 1 has a curved shape in which the surface 2 bulges from the two sides 4b, 4d toward the second straight line L2 passing through the center O, and the back surface 3 is recessed from the two sides 4b, 4d toward the second straight line L2. In other words, the plate-shaped member 1 is warped so that the surface 2 is a convex surface and the back surface 3 is a concave surface. As shown in FIG. 1(b), when the nail file is viewed from the right side of the paper, the nail file is warped so that the radius of curvature at the center of the plate thickness of the plate-shaped member 1 is, for example, 80.0 mm. In this embodiment, the nail file is warped so that the radius of curvature of the curved surface formed by the plate-shaped member 1 is constant in the cross section passing through the first straight line L1, but the radius of curvature does not have to be constant throughout the plate-shaped member 1. For example, the side of the plate-like member 1 closer to the second straight line L2, for example the area where the finger insertion hole 6 is formed, may be configured with a constant radius of curvature, and the radius of curvature may be made larger as it approaches the two sides 4b, 4d, or may be made closer to the XY plane.

[0037] Then, a file portion 7 is formed along a pair of opposing sides 4a, 4c of the front surface 2 and back surface 3 of the plate-like member 1 shaped as described above, so as to include four corners 5a to 5d. On the front surface 2 of the file portion 7, the portion along the side 4a is called the first file portion 7a, the portion along the side 4c is called the second file portion 7b, on the back surface 3, the portion along the side 4a is called the third file portion 7c, and the portion along the side 4c is called the fourth file portion 7d.

[0038] The first and third file portions 7a, 7c are formed over the entire area of ​​the portion of the plate-like member 1 located between the finger hole 6 and the side 4a on the front surface 2 and the back surface 3, respectively. Furthermore, the first and third file portions 7a, 7c are formed outside the finger hole 6 with approximately the same width as the dimension between the finger hole 6 and the side 4a on the second straight line L2, and are formed to reach the sides 4b, 4d.

[0039] The second and fourth file portions 7b, 7d are also formed over the entire area of ​​the portion of the plate-like member 1 located between the finger hole 6 and the side 4c on the front surface 2 and the back surface 3. Furthermore, the second and fourth file portions 7b, 7d are also formed outside the finger hole 6 with approximately the same width as the dimension between the finger hole 6 and the side 4c on the second straight line L2, and are formed to reach the sides 4b, 4d.

[0040] For this reason, the first file portion 7a and the second file portion 7b have convex file surfaces, and are laid out so that their longitudinal direction is along the X-axis, and they are arranged side by side on both sides of the Y-axis with the finger hole 6 in between. The third file portion 7c and the fourth file portion 7d have concave file surfaces, and are laid out so that their longitudinal direction is along the X-axis, and they are arranged side by side on both sides of the Y-axis with the finger hole 6 in between.

[0041] The first file portion 7a and the second file portion 7b formed on the front surface 2 side are each composed of a file surface of different grits, that is, different roughness. The third file portion 7c and the fourth file portion 7d formed on the back surface 3 side are also composed of a file surface of different grits. The first file portion 7a and the third file portion 7c formed on one side of the same Y-axis direction with respect to the finger insertion hole 6, that is, along the same side 4a, are composed of file surfaces of the same grit. Similarly, the second file portion 7b and the fourth file portion 7d formed on the other side of the same Y-axis direction with respect to the finger insertion hole 6, that is, along the same side 4c, are composed of file surfaces of the same grit. The roughness of the file surfaces of the first file portion 7a and the third file portion 7c and the second file portion 7b and the fourth file portion 7d can be set arbitrarily. For example, the former can be made to have a coarser file surface than the latter for rough grinding of nails, and the latter can be made to have a finer file surface than the former for fine grinding of nails. The file surfaces constituting the first to fourth file portions 7a to 7d can be formed by, for example, an etching process. The file surfaces may also be formed by other methods, such as machining.

[0042] In addition, the portion of the front surface 2 located between the first file portion 7a and the second file portion 7b, and the portion of the back surface 3 located between the third file portion 7c and the fourth file portion 7d are mirror-finished, but may be used as space for adding letters, patterns, etc.

[0043] [How to use a nail file] Next, a method of using the nail file configured as above will be described. Although a nail can be ground by using any one of the first to fourth file portions 7a to 7d provided on the nail file, one example will be described here.

[0044] (1) When grinding the nail plate FIG. 3 shows a case where the nail file is held in the right hand 10 and the nail 12 of the left hand 11 is ground using the third file part 7c on the far side of the paper. As described above, the first to fourth file parts 7a to 7d provided on the nail file are formed along the two long sides 4a, 4c of the approximately rectangular plate-like member 1. For this reason, as shown in FIG. 3, when the nail file is held in the right hand 10 and the nail 12 of the left hand 11 is ground, if the nail plate 12a is ground, for example, the two short sides 4b, 4d of the approximately rectangular plate-like member 1 are pinched with the fingertips. At this time, it is convenient to hold the third file part 7c to be used so that it is positioned on the outside of the right hand 10 and faces the left hand 11.

[0045] Then, the nail plate 12a is pressed against the third file portion 7c on the far side of the paper in Fig. 3, and the right hand 10 is moved to stroke the nail file along the longitudinal direction of the third file portion 7c as indicated by the dashed arrow in the figure. This allows the nail plate 12a to be roughly ground using the third file portion 7c, whose file surface is configured as a concave surface.

[0046] When performing rough grinding, if one wishes to use not only the concave third file portion 7c but also the convex first file portion 7a, the nail file is rotated around the second straight line L2 as the central axis and held upside down in the right hand 10. Then, as in the case of using the third file portion 7c, the nail plate 12a is pressed against the first file portion 7a and the nail file is stroked along the longitudinal direction of the first file portion 7a. This allows the nail plate 12a to be roughly ground using the first file portion 7a whose file surface is configured as a convex surface.

[0047] On the other hand, if you want to perform finish grinding using the fourth file portion 7d, rotate the nail file 180° clockwise from the state shown in FIG. 3 with the center O as the central axis, and hold the nail file upside down with the right hand 10. Then, while pressing the nail plate 12a against the fourth file portion 7d, stroke the nail file along the longitudinal direction of the fourth file portion 7d. This allows the nail plate 12a to be finish ground using the fourth file portion 7d, whose file surface is configured as a concave surface. Furthermore, if you want to perform finish grinding using the second file portion 7b, you can rotate the nail file with the second straight line L2 as the central axis when using the fourth file portion 7d.

[0048] In addition, the tip of the nail often has a convex curve that bulges outward from the finger 13, so when filing the entire width of the nail 12, the concave surface on the back surface 3 can be used to file efficiently, and when filing only a part of the nail 12, the convex surface on the front surface 2 can be used to file only part of the nail. It can be used in different ways according to the user's intentions.

[0049] (2) When grinding the lateral nail edge FIG. 4 shows a case where the nail file is held in the right hand 10 and the tip side of the lateral nail edge 12b of the nail 12 of the left hand 11 is ground using the part of the fourth file portion 7d located at the corner 5c. As shown in FIG. 4, when grinding the lateral nail edge 12b, the nail 12 is ground using, for example, the corner 5c. That is, the nail file is held so that the sides 4c and 4d face the outside of the right hand 10 and the side 4a faces the inside. At this time, if a part of the index finger 13a is inserted into the finger insertion hole 6, the index finger 13a contacts the inner wall surface of the finger insertion hole 6, and the thumb 13b contacts the vicinity of the side 4a, the nail file can be gripped and held more stably. In addition, it is easier to apply a load to the corner 5c when grinding the lateral nail edge 12b. Furthermore, by inserting a part of the middle finger 13c into the finger insertion hole 6 and gripping the nail file together with the index finger 13a and thumb 13b, the nail file can be held more firmly and stably. The position shown in Fig. 4 on the lateral nail edge 12b, that is, the boundary position between the part that is in contact with the skin on the toe side and the part that is not in contact with the skin on the toe side, becomes the load point 12c. When filing the nail 12 at this load point 12c, by filing using the corner 5c, the nail file can be held stably and can be used, and the fine parts on the toe side of the lateral nail edge 12b can be filed stably.

[0050] Then, the portion of the fourth file portion 7d near the corner 5c is pressed against the lateral nail edge 12b, and the corner 5c is finely slid along the lateral nail edge 12b to grind the lateral nail edge 12b. This allows the lateral nail edge 12b, which is difficult to grind, to be ground using the fourth file portion 7d formed at the corner 5c. In particular, in the nail file of this embodiment, the corner 5c is configured at an obtuse angle, so that the corner 5c does not get caught even when it hits the flesh around the lateral nail edge 12b, and it is possible to accurately grind even the fine details of the nail 12.

[0051] Furthermore, in the nail file of this embodiment, the corners 5c are rounded. Therefore, even if the corners 5c come into contact with the flesh around the side nail edge 12b, they can move smoothly, and the side nail edge 12b can be more smoothly ground.

[0052] FIG. 5 shows a case where the nail file is held in the right hand 10, and the part of the second file portion 7b located at the corner 5c is used to grind the tip side of the lateral nail edge 12b of the nail 12 of the left hand 11. As shown in this figure, when grinding the lateral nail edge 12b, the corner 5c of the second file portion 7b may be used to grind the nail 12. In that case, for example, the nail file is held with the side 4d facing the outside of the right hand 10 and the side 4b facing the inside. Then, by inserting a part of the index finger 13a into the finger insertion hole 6, the index finger 13a is in contact with the inner wall surface of the finger insertion hole 6, and the thumb 13b is in contact with the vicinity of the side 4c, the nail file can be gripped and held more stably. In this way, the same effect as in FIG. 4 can be obtained.

[0053] In this example, the corner 5c is used to grind the lateral nail edge 12b, but by changing the nail file, the other corners 5a, 5b, and 5d can be used to grind the finer details of the nail 12. Even when using the corners 5a to 5d in this way, the first to fourth file portions 7a to 7d, which have four different file surfaces with different roughness and surface irregularities, can be appropriately selected, so that the nail 12 can be ground more finely.

[0054] The way of holding the nail file is arbitrary and is not limited to the way shown in Figures 4 and 5. For example, the nail file can be held with the index finger 13a in contact with the side 4a away from the corner 5d and part of the thumb 13b in the inner wall surface of the finger hole 6. Furthermore, the nail file can be held by grasping the sides 4a and 4c without using the finger hole 6. It is sufficient for the user to hold the nail file in a way that is more convenient for the user, but the finger hole 6 allows more diverse ways of holding the nail file and also allows the nail file to be held closer to the nail 12 using the finger hole 6, making it possible to perform more detailed work.

[0055] [Effects of a nail file] (1) The nail file of this embodiment is composed of a substantially rectangular plate-like member 1 having four corners 5a-5d formed by four sides 4a-4d formed by two sets of two opposing sides. In this way, by making the nail file into a substantially rectangular shape, it is possible to make the outer shape wide, making it easy to handle when in use, and when grinding the nail 12 using the file part 7, it is possible to make the file part 7 less likely to come off the nail 12. In addition, since the nail file of this embodiment does not have a structure in which a separate handle part is provided on the file part, it has a compact shape and is easy to hold. Furthermore, in the case of a long and thin nail file with a handle, the nail may come off the file surface during use, but the nail file of this embodiment does not come off and can be used stably.

[0056] In addition, since the nail file has a width, it is less likely to bend even when force is applied during use compared to conventional long, thin board-like ones, and since the file part 7 is less likely to come off the nail 12, grinding can be performed with a large stroke.

[0057] (2) The nail file is also provided with finger holes 6 penetrating the front surface 2 and the back surface 3 on the inside surrounded by the sides 4a to 4d. Thus, by providing finger holes 6, a user can insert part of a finger 13 into finger hole 6 and hold the nail file with finger 13 in contact with the inner wall surface of finger hole 6, thereby gripping the nail file more stably. Of course, when using the nail file, the user may hold the nail file with finger 13 touching only the four sides 4a to 4d, the front surface 2, and the back surface 3, but by utilizing finger holes 6, the grip can be improved depending on how the nail file is used.

[0058] Furthermore, because the plate-like member 1 has a structure in which finger holes 6 are provided on the inside of each of the sides 4a to 4d, it is possible to improve the grip by using the finger holes 6 no matter what angle the nail file is held at with respect to the center O. In particular, because the finger hole 6 is elliptical, the fingers 13 can easily come into contact with the finger hole 6 no matter what angle the nail file is held at, making it easier to grip.

[0059] Furthermore, because finger hole 6 is shaped without corners, such as an oval, the load on finger 13 can be evenly distributed even when holding the nail file so that force is applied to the inner peripheral wall of finger hole 6. Also, because finger hole 6 can be shaped to follow sides 4a, 4c, the width of the nail file can be ensured on both sides of finger hole 6, and the width of file portion 7 can be made approximately the same in the longitudinal direction. Therefore, the file portion can be configured to be wide on both sides of finger hole 6, and can be shaped to extend curvedly toward sides 4a, 4c with approximately the same width, giving the nail file a more attractive design.

[0060] (3) On at least one of the front surface 2 and the back surface 3 of the plate-shaped member 1 constituting the nail file, the file portion 7 is formed along one pair of opposing sides 4a, 4c and includes four obtuse angled corners 5a to 5d.

[0061] If the file part 7 of the corners 5a to 5d is used, when the lateral nail edge 12b is filed, the file part 7 is less likely to hit the flesh of the finger 13 than when the file part 7 is filed at the sides 4a and 4c. Therefore, fine areas such as the outer edge of the nail 12, including the lateral nail edge 12b, can be well ground, and the problem of the file part 7 hitting the flesh of the finger 13 can be eliminated. In addition, if the four corners 5a to 5d are right angles or acute angles, the file area of ​​the corners 5a to 5d is small, so the nail is easily displaced from the file part 7 and it is difficult to file the nail 12 evenly over a wide area. However, since the four corners 5a to 5d are obtuse angles, the file area of ​​the corners 5a to 5d can be made large, and it is possible to file the nail 12 evenly over a wide area while filing the fine details.

[0062] In addition, the four corners 5a to 5d are rounded, which further prevents the corners 5a to 5d from catching on the skin around the nail 12 when the nail 12 is filed with the file portion 7, and the feel when the corners hit the skin is softer than when the four corners 5a to 5d are sharp.

[0063] (4) The sides 4a and 4c are symmetrical about the first straight line L1, and the sides 4b and 4d are symmetrical about the second straight line L2. The nail file has a curved shape in which the front surface 2 bulges from the sides 4b and 4d toward the second straight line L2, and the back surface 3 is recessed from the sides 4b and 4d toward the second straight line L2.

[0064] In this way, by warping the nail file into a curved shape, the file surface of the file portion 7 can be curved to accommodate various nail shapes. Also, the curved shape creates a portion that is raised above the desk, making it easier to hold the nail file from the desk compared to when the nail file is flat.

[0065] The nail file has a curved shape, and is provided with a first file portion 7a and a second file portion 7b on the front surface 2, and a third file portion 7c and a fourth file portion 7d on the back surface 3.

[0066] In this way, the file portion 7 is provided on different curved surfaces, the front surface 2 which is a convex surface, and the back surface 3 which is a concave surface, so that different types of file portion 7 can be provided on the front surface 2 side and the back surface 3 side. Therefore, the nail 12 can be filed more finely by using different types of file portion 7 depending on the part of the nail 12 to be filed.

[0067] Furthermore, the first file portion 7a and the second file portion 7b formed on the front surface 2 are configured to have different roughnesses. Also, the third file portion 7c and the fourth file portion 7d formed on the back surface 3 are configured to have different roughnesses.

[0068] In this way, by providing file portions 7 of different coarseness on the same surface, the user can grind the nail 12 using file portions 7 of the coarseness that the user desires to use on the front and back of the nail file. It is also possible to first perform rough grinding with the coarse file portion 7, and then perform finish grinding with the fine file portion 7. This makes it possible to shorten the time required for finishing compared to performing all finish grinding.

[0069] Furthermore, when two file portions 7 with different roughness are provided on each of the front surface 2 and the back surface 3, two file portions 7 with different roughness can be configured on each of the front surface 2, which is a convex surface, and the back surface 3, which is a concave surface, so that a total of four file portions 7 with different roughness can be configured on the front and back surfaces. Therefore, the four types of file portions 7 can be used to file nails more finely.

[0070] In the configuration in which the first to fourth file portions 7a to 7d are formed, the first file portion 7a and the third file portion 7c formed along the same side 4a have the same roughness, and the second file portion 7b and the fourth file portion 7d formed along the same side 4c have the same roughness. In this way, by making the roughness of the file portions 7 located on the same side on the front and back of the nail file uniform, whether the nail is filed on the front or back, the nail can be filed while recognizing that the file portions 7 with uniform roughness are on the same side. Therefore, the nail 12 can be easily filed without checking the roughness of the file portions 7 when the nail file is turned over to file.

[0071] The nail file is manufactured by pressing a substantially rectangular flat plate to bend, and then performing an etching process to form the file portion 7. In the etching process, etching is performed to roughen the surface while masking the areas not to be etched. At this time, if the roughness of the first file portion 7a and the third file portion 7c along the same side 4a is made uniform, and the roughness of the second file portion 7b and the fourth file portion 7d along the same side 4c is made uniform, the etching process can be performed simultaneously by simply masking the areas not to be etched and turning the nail file over. For example, when forming the first file portion 7a and the third file portion 7c, the other areas are masked, and after forming the first file portion 7a by etching, the third file portion 7c can be formed by turning the nail file over. In this way, the manufacturing process of the nail file can be simplified.

[0072] (5) The nail file of this embodiment is composed of a plate-like member 1 having a substantially rectangular shape, and has a shape formed in the center with a finger hole 6 extending along a first straight line L1, that is, a shape reminiscent of a sword tsuba 100 as shown in FIG. 6. This allows the nail file to be a product that combines design and functionality by integrating the traditional Japanese shape with the function of a file, and it can also be used as an objet d'art when not in use. Furthermore, because the nail file is made of metal, it can be given a sense of solidity and high rigidity, and can also be given the image of a sword tsuba 100.

[0073] (Other embodiments) The present disclosure is not limited to the above-described embodiment, and can be appropriately modified within the scope of the claims. In addition, in the above-described embodiment, it goes without saying that the elements constituting the embodiment are not necessarily essential, except when they are specifically stated as essential or when they are clearly considered essential in principle. In addition, in the above-described embodiment, when the numbers, values, amounts, ranges, etc. of the components of the embodiment are mentioned, they are not limited to the specific numbers, except when they are specifically stated as essential or when they are clearly limited to a specific number in principle. In addition, in the above-described embodiment, when the shapes, positional relationships, etc. of the components are mentioned, they are not limited to the shapes, positional relationships, etc., except when they are specifically stated or when they are limited to a specific shape, positional relationship, etc. in principle.

[0074] For example, the above-mentioned method of using the nail file is an example, and the user may use it in a way that is convenient for the user. In particular, since the nail file has a file surface on a curved surface, it can be adjusted to various angles to grind the nail 12, so the user can use it in a way that suits them depending on the shape of their nail 12, the size of their hand, etc.

[0075] In the above embodiment, the four corners 5a to 5d are configured with the same curvature, but they may have different curvatures. For example, two of the corners 5a to 5d that are diagonally or symmetrically arranged across the first straight line L1 may have the same curvature. In that case, two corners with different curvatures can be configured for the file portion 7 with the same roughness.

[0076] In addition, in the above embodiment, one example of finger insertion hole 6 is shown, but the shape and dimensions of finger insertion hole 6 are also shown as merely one example. The shape of finger insertion hole 6 is not limited to an ellipse, and other shapes are also acceptable, such as an oval shape whose major axis is along first straight line L1 and whose minor axis is along straight line L2. Finger insertion hole 6 only needs to have a size that allows part of finger 13 to fit therein, and does not need to have a size that allows finger 13 to fit in all the way to its base.

[0077] 1(a) and the like, the first to fourth file portions 7a to 7d may be formed on the inside of the nail file from the sides 4a to 4d, that is, away from the boundaries between the front surface 2 and back surface 3 and the end faces connecting them, or may be formed to be in contact with the boundaries. When the first to fourth file portions 7a to 7d are formed on the inside of the nail file from the sides 4a to 4d, the distances from the boundaries between the front surface 2 and back surface 3 and the end faces to the first to fourth file portions 7a to 7d may be set so that grinding is possible at the corners 5a to 5d.

[0078] In the above embodiment, each of the four sides 4a to 4d is curved such that the distance between the two opposing sides is wider on the inside than at both ends of each side. However, when viewed from the front of the nail file, all of the four sides 4a to 4d may be straight lines, or one pair of opposing sides may be curved and the other pair of opposing sides may be straight lines.

[0079] Furthermore, in the above embodiment, all of the four corners 5a to 5d are obtuse angles, but they do not necessarily have to be obtuse angles. For example, when the nail file is viewed from the front, the plate-shaped member 1 may have another shape having four sides 4a to 4d and four corners 5a to 5d, such as a substantial rhombus or a substantial parallelogram. [Explanation of symbols]

[0080] 1...plate-shaped member, 2...surface, 3...back surface, 4a-4d...sides, 5a-5d...corners, 6...finger insertion hole, 7...file portion, 7a-7d...first to fourth file portions, 10...right hand, 11...left hand, 12...nail, 12a...nail plate, 12b...lateral nail plate edge, 13...finger, 13a...index finger, 13b...thumb, 100...tsuba, L1...first straight line, L2...second straight line, O...center

Claims

1. The plate-like member (1) has a surface (2) and a back surface (3) opposite the surface (2), four sides (4a to 4d) formed by two pairs of opposing sides, and four corners (5a to 5d) formed by the four sides; The nail file has a finger hole (6) formed inside the plate-like member surrounded by the four sides, penetrating the front and back surfaces, and file portions (7, 7a to 7d) formed on at least one of the front and back surfaces along each of two sides of one of the two opposing pairs of sides and including the four corners.

2. 2. The nail file according to claim 1, wherein each of the four corners is rounded.

3. 2. The nail file of claim 1, wherein said four corners are obtuse angles.

4. 2. The nail file according to claim 1, wherein each of the four sides is curved such that the distance between the two opposing sides is wider on the inner side than on both ends of each side.

5. 5. The nail file of claim 4, wherein said four corners are obtuse angles.

6. each of the four sides is rounded and each of the four corners is rounded, and a radius of curvature of the R-shape of the four corners is smaller than a radius of curvature of the R-shape of the four sides; 6. The nail file according to claim 5, wherein each of the four corners has an obtuse angle formed by intersecting tangents at both ends of a rounded portion of the corner.

7. The nail file of any one of claims 1 to 6, wherein the two sides (4a, 4c) of one of the two opposing pairs of sides are linearly symmetrical with respect to a first straight line (L1) passing through the center (O) of the plate-shaped member, and the two sides (4b, 4d) of the other of the two opposing pairs of sides are linearly symmetrical with respect to a second straight line (L2) passing through the center and perpendicular to the first straight line, and the front surface bulges as it approaches the second straight line from the other pair of sides, and the back surface is curved in a concave shape as it approaches the second straight line from the other pair of sides.

8. The plate-like member has two sides of the one set longer than two sides of the other set, and a direction along the first straight line is a longitudinal direction and a direction along the second straight line is a lateral direction, The nail file according to claim 7, wherein the finger insertion hole is elliptical in shape with a major axis extending along the first straight line and a minor axis extending along the second straight line.

9. The file portion is formed on both the front surface and the back surface, The file portion formed on the surface includes a first file portion (7a) formed along one of the two sides of the one set, and a second file portion (7b) formed along the other of the two sides of the one set, The nail file of claim 8, wherein the file portion formed on the back surface is configured to have a third file portion (7c) formed along one of the two sides of the said set and opposite the first file portion, and a fourth file portion (7d) formed along the other of the two sides of the said set and opposite the second file portion.

10. The first file portion and the second file portion have different roughnesses, 10. The nail file of claim 9, wherein the third file portion and the fourth file portion have different roughnesses.

11. The first file portion and the third file portion have the same roughness, The nail file of claim 10, wherein the second file portion and the fourth file portion have the same roughness.

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