Toothbrush

Abstract

The utility model provides a toothbrush which reliably transmits force applied to a holding part to a bristle planting part while restraining bending of a neck so as to give consideration to operability in an oral cavity and reliable tooth brushing feeling. A toothbrush (100) is provided with a brush body (110), and the brush body (110) is provided with: a head part (10) that is disposed on the tip side in the longitudinal direction and that has a bristle planting surface (11); a neck part (20) disposed on the rear end side of the head part (10); and a grip section (30) disposed at a position closer to the rear end than the neck section (20), the neck section (20) being a linear shape having an elongated, flat, substantially quadrilateral cross-sectional shape, the length D1 and the length W1 being constant when the length of the neck section (20) in the thickness direction is D1 and the length of the neck section (20) in the width direction is W1, and the grip section (30) being disposed at a position closer to the rear end than the neck section (20). The length (W1) and the length (D1) satisfy the relationship D1 > W1 and extend in the long axis direction.

Description

Technical Field

[0001] This utility model relates to a toothbrush. Background Technology

[0002] Typically, a toothbrush needs to balance operability within the mouth and a reliable brushing sensation; the design of the neck and handle is important in achieving these. In particular, to achieve a reliable brushing sensation, it is necessary to control the deflection from the neck to the handle.

[0003] Currently, to ensure operability in the oral cavity, many toothbrushes have necks with a narrow cross-sectional shape. In particular, from the viewpoint of ensuring the strength of the boundary between the neck and the handle, the neck is mostly wide and thick, gradually increasing in width and thickness towards the handle, and connected in a gentle R-shape. However, such a shape flexes from the neck throughout the entire handle during brushing, resulting in a loss of force applied to the handle, raising concerns about a reduction in reliable brushing sensation.

[0004] In addition, Patent Document 1 discloses a toothbrush with an S-shaped neck for intraoral operation.

[0005] Prior art literature

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 7086002 Utility Model Content

[0008] The problem to be solved by the utility model

[0009] The toothbrush in Patent Document 1 improves operability in the oral cavity by setting the neck to an S-shape, but on the other hand, it is difficult to directly transmit the force from the handle to the bristle part relative to the brushing direction (the direction in which brushing pressure is applied), which raises concerns about a decrease in reliable brushing sensation.

[0010] At least one embodiment of the present invention was made in view of the above circumstances. Specifically, a toothbrush is provided that can reliably transmit the force applied to the handle to the bristle section while suppressing the flexion of the neck, so as to take into account both operability in the oral cavity and reliable brushing sensation.

[0011] Technical solutions for solving the problem

[0012] The above-mentioned objective of this utility model is achieved by any one of the following (1) to (7).

[0013] (1) A toothbrush having a brush body comprising: a head disposed at a front end in the long axis direction and having a bristle-embedded surface; a handle disposed at a rear end of the head; and a neck connecting the head to the handle, the neck being a straight line having a longitudinally elongated and flattened generally quadrilateral cross-sectional shape, wherein when the length in the thickness direction of the neck is defined as D1 and the length in the width direction is defined as W1, the lengths D1 and W1 are constant values, and the lengths W1 and D1 extend along the long axis direction satisfying the relationship D1 > W1.

[0014] (2) The toothbrush according to (1) above, wherein the ratio of the length W1 of the neck to the length D1, W1 / D1, is less than 0.8.

[0015] (3) The toothbrush according to (1) or (2) above, wherein the toothbrush has a transition portion between the neck and the handle portion, the length in the width direction and the length in the thickness direction of the transition portion increase from the neck toward the handle portion, and when the length in the long axis direction of the neck is set as L1 and the length in the long axis direction of the transition portion is set as L2, the ratio of the length L2 to the length L1, L2 / L1, is less than 0.6.

[0016] (4) The toothbrush according to any one of (1) to (3) above, wherein the length D2 that forms the minimum thickness of the head is 2.0 mm or more and 3.5 mm or less, the ratio of the length D2 to the length D1, D2 / D1, is less than 0.8, the length W2 that forms the maximum width of the head is 10.0 mm or more and 15.0 mm or less, and the ratio of the length W1 to the length W2, W1 / W2, is less than 0.4.

[0017] (5) The toothbrush according to any one of (1) to (4) above, wherein the grip portion is a straight shape having a generally quadrilateral cross-sectional shape, and when the length that will become the maximum thickness of the grip portion is set as D3 and the length that will become the maximum width of the grip portion is set as W3, the length D3 and the length W3 are constant values, and the surface of the grip portion extends in a constant shape along the long axis direction parallel to the bristle surface, the ratio of the length D3 to the length D1, D1 / D3 is greater than 0.3, the ratio of the length W1 to the length W3, W1 / W3 is less than 0.5, the transition portion connects the ridge line formed in the area of ​​the neck and the area formed in the grip portion, and the width and thickness of the transition portion increase from the front end toward the base end.

[0018] (6) The toothbrush according to any one of (1) to (5) above, wherein the difference between the length W2, which is the maximum width of the head, and the length W3, which is the maximum width of the grip, is within 2.0 mm.

[0019] (7) The toothbrush according to any one of (1) to (6) above, wherein the brush body is formed of hard resin.

[0020] Utility Model Effect

[0021] According to the toothbrush of this invention, the neck is a straight line with a generally quadrilateral cross-section. The length D1 in the thickness direction and the length W1 in the width direction of the neck are constant values, and the lengths W1 and D1 satisfy the relationship D1 > W1 and extend along the long axis. Therefore, the neck bends at the rear end (handle side), and the deflection of the neck in the width and thickness directions is minimized, while the force applied to the handle is transmitted to the head. Furthermore, since the neck is a straight line, the force applied to the handle is reliably transmitted to the teeth in the vertical direction. Therefore, the toothbrush of this invention can minimize the deflection of the neck while reliably transmitting the force applied to the handle to the bristle section, thus balancing intraoral operability and a reliable brushing feel. Attached Figure Description

[0022] Figure 1 This is a planar perspective view of the toothbrush involved in this utility model.

[0023] Figure 2 This is a perspective view of the bottom side of the toothbrush involved in this utility model.

[0024] Figure 3 This is a front view of the toothbrush involved in this utility model.

[0025] Figure 4 This is a rear view of the toothbrush involved in this utility model.

[0026] Figure 5 This is a top view of the toothbrush involved in this utility model.

[0027] Figure 6 This is a bottom view of the toothbrush involved in this utility model.

[0028] Figure 7 This is a left-side view of the toothbrush involved in this utility model.

[0029] Figure 8 This is a right-side view of the toothbrush involved in this utility model.

[0030] Figure 9 This is a partial enlarged top view of the toothbrush involved in this utility model, from the head to the front periphery of the handle.

[0031] Figure 10 This is a partial enlarged view of the toothbrush involved in this utility model from the head to the front periphery of the handle.

[0032] Figure 11 This is a diagram showing the boundaries P1 to P3 and line segment A1 of the toothbrush involved in this utility model.

[0033] Figure 12 This is a cross-sectional view along line A-A of the toothbrush involved in this utility model.

[0034] Figure 13 This is a B-B cross-sectional view of the toothbrush involved in this utility model.

[0035] Figure 14 This is a C-C cross-sectional view of the toothbrush involved in this utility model.

[0036] Figure 15 This is a D-D cross-sectional view of the toothbrush involved in this utility model. Detailed Implementation

[0037] Hereinafter, the embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. The embodiments shown herein are illustrative to concretize the technical concept of the present invention and are not intended to limit the present invention. Furthermore, all other methods, embodiments, and techniques that can be implemented by those skilled in the art without departing from the spirit of the present invention are included within the scope and spirit of the present invention, and are included within the scope of the patent claims and their equivalents.

[0038] In addition, for ease of illustration and understanding, the accompanying drawings may have been modified in a schematic manner relative to the actual object, such as in terms of scale, aspect ratio, and shape. However, this is only one example and does not limit the interpretation of this utility model.

[0039] In each figure, the arrows X1-X2 forming the X-axis indicate the length direction of the toothbrush 100. Arrow X1 indicates the front end side (head 10 side) of the toothbrush 100, and arrow X2 indicates the rear end side (handle 30 side) of the toothbrush 100. Additionally, the arrows Y1-Y2 forming the Y-axis in each figure indicate the width direction of the toothbrush 100. Furthermore, the arrows Z1-Z2 forming the Z-axis in each figure indicate the thickness direction of the toothbrush 100.

[0040] In this specification, "top view" refers to viewing the toothbrush 100 from the side of the bristle-embedded surface 11 of the head 10, and "bottom view" refers to viewing the toothbrush 100 from the side opposite to the bristle-embedded surface 11 of the head 10 (see reference). Figure 5 , Figure 6The main view refers to the view taken from a direction orthogonal to the thickness direction of the head 10 (see reference). Figure 3 ). Figure 4 The rear view shown is the same as Figure 3 The front view shown is symmetrically represented.

[0041] In addition, the "surface" of the holding part 30 refers to the surface facing the same direction as the hair-planting surface 11, which is the surface of the head 10 where hair bundles 13 are planted. The "back side" refers to the surface opposite to the "surface". The "side side" refers to the surface other than the "surface", "back side" and the surface of the base end side.

[0042] Appropriate reference Figures 1-15 The toothbrush 100 according to this embodiment will be described. It should be noted that in each figure, lines representing the shape of a portion of the angle R are shown as needed for easy understanding of the shape.

[0043] Figures 1 to 8 The shape of the toothbrush 100 of this embodiment is shown. Figure 1 This is a three-dimensional view of toothbrush 100 viewed from a planar perspective (planar perspective three-dimensional view). Figure 2 This is a three-dimensional view of the toothbrush 100 viewed from the bottom side (bottom side three-dimensional view). Figure 3 This is a front view of toothbrush 100. Figure 4 This is a rear view of the toothbrush 100. Figure 5 This is a top-down view of the toothbrush 100. Figure 6 This is a diagram of a toothbrush 100 viewed from below (bottom view). Figure 7 This is a diagram of toothbrush 100 viewed from the left side (left-side view). Figure 8 This is a view of toothbrush 100 from the right side (right side view).

[0044] like Figures 1 to 8 As shown in any one of the embodiments, the toothbrush 100 has: a head 10 disposed at the front end in the long axis direction and having a bristle-embedded surface 11 in which bristle bundles 13 are embedded; a neck 20 disposed on a side further rearward than the head 10; a handle 30 disposed on a side further rearward than the neck 20; and a transition portion 40 disposed between the neck 20 and the handle 30. The toothbrush 100 has a brush body 110 having the head 10, the neck 20, the handle 30, and the transition portion 40.

[0045] The brush body 110 is integrally molded into a long strip shape and can be molded using a rigid resin. Examples of rigid resins constituting the brush body 110 include polypropylene (PP), polyacetal (POM), polycyclohexanediol terephthalate (PCT), polyethylene terephthalate (PET), polycarbonate (PC), acrylonitrile-butadiene-styrene resin (ABS), polymethyl methacrylate (PMMA), polystyrene (PS), acrylonitrile-butadiene-styrene resin (ABS), cellulose propionate (CP), and polyarylates. Furthermore, biodegradable resins, plant-derived resins, paper-mixed resins, and plant-mixed resins can also be used. Among these resins, polypropylene resin (PP) is preferred as it provides the most significant effects of this invention.

[0046] Furthermore, the brush body 110 is preferably formed entirely of the same hard resin. If the brush body 110 is formed of the same hard resin, the force applied to the grip portion 30 can be properly transmitted to the head 10. If a part of the grip portion 30 contains soft resin, the force when gripping is dispersed within the soft resin, making it difficult to reliably transmit the gripping force to the front end of the grip portion 30.

[0047] In this embodiment, the boundary P1 between the head 10 and the neck 20, the boundary P2 between the neck 20 and the transition portion 40, and the boundary P3 between the transition portion 40 and the gripping portion 30 are defined as follows.

[0048] The boundary P1 between the head 10 and the neck 20 is as follows Figure 5 , Figure 9 As shown, this is the position of the endpoint of the narrowing of the head 10 in the top view shape, or as... Figure 11 The figure shows the position of the end point of the thickness expansion of the head 10 in the main view shape. However, regarding the boundary P1, since the positions of the aforementioned end points are offset in the long axis direction, the position of the end point closer to the gripping part 30 is set as the boundary position.

[0049] The boundary P2 between the neck 20 and the transition section 40 is as follows Figure 5 , Figure 9 As shown, this is the starting point of the width expansion of the transition section 40 in the top view shape, or as... Figure 11 The figure shows the starting point of the thickness expansion of the transition portion 40 in the main view shape. However, regarding the boundary P2, since the positions of the aforementioned starting points are offset in the long axis direction, the position of the starting point closer to the head 10 side is set as the boundary position.

[0050] The boundary P3 between the transition section 40 and the holding section 30 is as follows Figure 5 , Figure 9 As shown, this is the position of the end point of the width expansion of the transition section 40 in the top view shape, or as... Figure 11 The figure shows the position of the end point of the thickness expansion of the transition portion 40 in the main view shape. However, regarding the boundary P3, since the positions of the aforementioned end points are offset in the long axis direction, the position of the end point closer to the grip portion 30 is set as the boundary position.

[0051] <Head>

[0052] like Figure 1 , Figure 3 , Figure 5 As shown, the head 10 is disposed on the front end side of the toothbrush 100 and has a structure integrally connected with the neck 20. The head 10 has a bristle-embedded surface 11 on one side in the thickness direction. Multiple bristle-embedded holes 12 are formed on the bristle-embedded surface 11, and bristle bundles 13 are embedded in the bristle-embedded holes 12. The multiple bristle bundles 13 constitute a brush portion 14. The toothbrush 100 can clean the oral cavity through the brush portion 14 of the head 10.

[0053] The material of the bristles constituting the bristles 13, the number of bristles in each bristle 13, and the number of bristle 13 configurations can be arbitrarily selected. Examples of bristle shapes include bristles whose diameter gradually decreases towards the bristle tip (conical bristles) and bristles whose diameter is approximately the same from the bristle-planting surface 11 towards the bristle tip (straight bristles). Examples of straight bristles include those with bristle tips set on a plane approximately parallel to the bristle-planting surface 11, and those with bristle tips rounded into a hemispherical shape. The cross-sectional shape of the bristles is not particularly limited and can be circular, oval, polygonal, star-shaped, clover-shaped, four-leaf clover-shaped, etc. All bristles can have the same or different cross-sectional shapes.

[0054] like Figure 10 As shown, the length D2 that constitutes the minimum thickness of the head 10 can be defined as the thickness of the head 10 at the position where the thickness of the head 10 is minimum in the Z-axis direction. The lower limit of the aforementioned length D2 is preferably 2.0 mm or more. The upper limit of the aforementioned length D2 is preferably 3.5 mm or less.

[0055] like Figure 9 As shown, the length W2, which represents the maximum width of the head 10, can be defined as the width of the head 10 at the position where the width of the head 10 is maximum in the Y-axis direction. The lower limit of the aforementioned length W2 is preferably 10.0 mm or more, more preferably 11.0 mm or more. The upper limit of the aforementioned length W2 is preferably 15.0 mm or less, more preferably 12.5 mm or less.

[0056] The head 10 preferably has ribs 15 on the bottom surface 16 on the rear end side, and can be configured to have a continuous shape in which the thickness transitions from the minimum thickness of the head 10 to the thickness of the neck 20, the length D2.

[0057] like Figure 11 As shown, the head 10 is preferably configured to overlap with the extension of the line segment A1 connecting the midpoint of the grip portion 30 in the thickness direction when viewed from the front (and rear) view. Furthermore, the head 10 is more preferably configured to completely overlap with the extension of the line segment A1 connecting the midpoint of the grip portion 30 in the thickness direction (a position penetrating the interior of the head 10 when viewed from the side). Thus, the toothbrush 100 can reliably transmit the force applied to the grip portion 30 to the teeth in the vertical direction.

[0058] <Neck>

[0059] like Figure 1 , Figure 3 , Figure 5 As shown, the front end of the neck 20 is adjacent to the base end of the head 10, and the base end of the neck 20 is adjacent to the front end of the transition portion 40. The neck 20 is formed into a straight line shape with a longitudinally elongated and flat (longitudinal flattened) approximately quadrilateral cross-section. It should be noted that "approximately quadrilateral" refers to a shape with an angle R of 5.0 or less.

[0060] Figure 12 This is a cross-sectional view of the boundary P1 between the head 10 and the neck 20. (See diagram below.) Figure 12 As shown, the length D1 of the neck 20 in the thickness direction can be defined as the thickness of the neck 20 in the Z-axis direction. The lower limit of the aforementioned length D1 is preferably 5.0 mm or more. The upper limit of the aforementioned length D1 is preferably 6.0 mm or less.

[0061] like Figure 12 As shown, the length W1 of the neck 20 in the width direction can be defined as the thickness of the neck 20 in the Y-axis direction. The lower limit of the aforementioned length W1 is preferably 3.0 mm or more. The upper limit of the aforementioned length W1 is preferably 4.0 mm or less.

[0062] like Figure 9 As shown, the length L1 of the neck 20 in the major axis direction can be defined as the total length of the neck 20 in the X-axis direction. The lower limit of the aforementioned length L1 is preferably 30 mm or more. The upper limit of the aforementioned L1 is preferably 40 mm or less.

[0063] like Figure 12 As shown, regarding the neck 20, when the length in the thickness direction is set as D1 and the length in the width direction is set as W1, both lengths D1 and W1 remain constant, satisfying the relationship D1 > W1 and extending along the major axis. It should be noted that "constant" means that both lengths D1 and W1 are ±0.5mm or W1 / D1 is ±0.1mm.

[0064] In conventional toothbrushes, if the lengths of the neck in both the width and thickness directions are set to D1 > W1, there is a concern about the neck bending in the width direction. In contrast, the toothbrush 100 of this embodiment has a neck 20 with a longitudinally elongated and flattened, approximately quadrilateral cross-sectional shape. Furthermore, the lengths D1 and W1 are constant values, and the relationship D1 > W1 is satisfied as the neck extends from the base of the head 10 towards the handle 30 along its long axis. As a result, the neck 20 bends at the rear end (handle 30 side), making it less prone to bending. That is, in the case of the toothbrush 100, when the bending point is located at the rear end of the neck 20, the distance from the head 10 (point of action) becomes greater, and the bending point is located in the transition portion 40 where resin content is high, thus making it less prone to bending. As a result, the toothbrush 100 can minimize the deflection in the thickness and width directions of the neck 20 while ensuring operability in the oral cavity, and transmit the force applied to the handle 30 to the head 10, thus achieving a reliable brushing sensation.

[0065] The ratio of the thickness length D1 of the neck 20 to the width length W1, W1 / D1, is less than 0.8. The lower limit of W1 / D1 is preferably 0.5 or more. The upper limit of W1 / D1 is preferably 0.75 or less.

[0066] In conventional toothbrushes, the ratio of the neck's length in the width direction to its length in the thickness direction is not specified because there is concern that increased deflection of the neck in the width direction would reduce its operability within the mouth. In contrast, the toothbrush 100 of this embodiment extends the neck 20 in a straight line along its long axis with a W1 / D1 < 0.8, thereby minimizing deflection of the neck 20 in both the thickness and width directions. Therefore, the toothbrush 100 can more effectively transmit the force applied to the grip 30 to the head 10.

[0067] When the length D2, which constitutes the minimum thickness of the head 10, is 2.0 mm or more and 3.5 mm or less, the ratio D2 / D1 of the length D2, which constitutes the minimum thickness of the head 10, to the length D1 in the thickness direction of the neck 20 is less than 0.8. The lower limit of D2 / D1 is preferably 0.3 or more. The upper limit of D2 / D1 is preferably 0.7 or less.

[0068] When the length W2 of the maximum width of the head 10 is 10.0 mm or more and 15.0 mm or less, the ratio W1 / W2 of the width direction length of the neck 20 to the length W2 of the maximum width of the head 10 is less than 0.4. The upper limit of the above-mentioned W1 / W2 is preferably 0.35 or less.

[0069] In conventional toothbrushes, when the head thickness is greater than 3.5 mm, the D2 / D1 ratio is 0.8 or more (D2 / D1≥0.8), and the W1 / W2 ratio is 0.4 or more (W1 / W2≥0.4), the thickness between the head and neck does not vary drastically, thus raising concerns about overall deflection of the head and neck. Furthermore, in such shapes, intraoral operability for molars may be reduced. In contrast, the toothbrush 100 of this embodiment has the following shape: the length D2, which constitutes the minimum thickness of the head 10, is 2.0 mm or more and 3.5 mm or less, and the D2 / D1 ratio is less than 0.8 (D2 / D1<0.8); the length W2, which constitutes the maximum width of the head 10, is 10.0 mm or more and 15.0 mm or less, and the W1 / W2 ratio is less than 0.4 (W1 / W2<0.4). As a result, the thickness (in the thickness and width directions) of the head 10 and neck 20 of the toothbrush 100 varies greatly, thus suppressing the flexing of the head 10 and neck 20 to achieve a reliable brushing sensation, and also improving operability in the oral cavity.

[0070] The lower limit of the difference between the length D1 of the neck 20 in the thickness direction and the minimum thickness D2 of the head 10 is preferably 1.5 mm or more. In addition, the upper limit of the difference between the length D1 and the D2 is preferably 4.0 mm or less.

[0071] The lower limit of the difference between the length W2, which is the maximum width of the head 10, and the length W1, which is the width direction of the neck 20, is preferably 8.0 mm or more. Furthermore, the upper limit of the difference between the aforementioned length W2 and the aforementioned length W1 is preferably 9.5 mm or less.

[0072] The value obtained by multiplying the ratio of the length D1 in the thickness direction of the neck 20 to the length W1 in the width direction of the neck 20 by the length L1 in the major axis direction of the neck 20 ((D1 / W1)×L1) is preferably greater than 30. The lower limit of (D1 / W1)×L1>30 is preferably 40 or more.

[0073] The larger the value obtained from the above formula ((D1 / W1)×L1), the longer and flatter the neck 20 becomes, with a longer straight area. Therefore, the toothbrush 100 can reliably transmit the force applied to the handle 30 to the head 10.

[0074] <Control Section>

[0075] like Figure 1 , Figure 3 , Figure 5 As shown, the front end of the holding part 30 is disposed adjacent to the base end of the transition part 40. The holding part 30 is held by the user with his / her fingers or the like when cleaning (brushing) the inside of the mouth.

[0076] The gripping part 30 is a straight line shape with a roughly quadrilateral cross-section. It should be noted that "roughly quadrilateral" means a shape with an angle R of 5.0 or less.

[0077] Figure 13 This is a cross-sectional view of the boundary P3 between the transition section 40 and the holding section 30. Figure 14 This is a cross-sectional view of the portion of the gripping part 30 having the back side R part 31. Figure 15 This is a cross-sectional view of the portion of the gripping part 30 having a back-side R-section 31 on the other side. It should be noted that in this embodiment, the radius of curvature of the angle R of the back-side R-section 31 of the gripping part 30 varies slightly. (As...) Figure 13 , Figure 14 , Figure 15 As shown, the length D3 in the thickness direction of the gripping portion 30 can be defined as the thickness of the gripping portion 30 in the Z-axis direction. The lower limit of the aforementioned length D3 is preferably 10.0 mm or more. The upper limit of the aforementioned length D3 is preferably 15.0 mm or less.

[0078] like Figure 13 , Figure 14 , Figure 15 As shown, the length W3 of the gripping portion 30 in the width direction can be defined as the width of the gripping portion 30 in the Y-axis direction. The lower limit of the aforementioned length W3 is preferably 10.0 mm or more. The upper limit of the aforementioned length W3 is preferably 15.0 mm or less.

[0079] like Figure 15 As shown, regarding the gripping portion 30, when the length in the thickness direction is set to D3 and the length in the width direction is set to W3, both lengths D3 and W3 are constant values, and the surface of the gripping portion 30 extends in a constant shape in the long axis direction parallel to the flocking surface 11. It should be noted that "constant" means that both lengths D3 and W3 are ±0.5mm.

[0080] Since the lengths D3 and W3 of the gripping portion 30 are both constant values, and the surface of the gripping portion 30 is a straight line extending in a constant shape parallel to the bristle-embedded surface 11 in the long axis direction, the force applied to the gripping portion 30 can be reliably transmitted to the teeth in the vertical direction. In the gripping portion 30 of this embodiment, although the radius of curvature of the back side R portion 31 varies slightly, the difference in the radius of curvature is small, and the gripping portion 30 as a whole can achieve the aforementioned effect.

[0081] The ratio D1 / D3 of the thickness direction length D1 of the neck 20 to the thickness direction length D3 of the gripping portion 30 is preferably greater than 0.3. The lower limit of the above-mentioned D1 / D3 is preferably 0.4 or more. The upper limit of the above-mentioned D1 / D3 is preferably 0.5 or less.

[0082] The ratio W1 / W3 of the width direction length of the neck 20 to the width direction length W3 of the gripping portion 30 is less than 0.5. The upper limit of the above-mentioned W1 / W3 is preferably 0.4 or less.

[0083] In conventional toothbrushes, when the D1 / D3 ratio is 0.3 or less (D1 / D3≤0.3) and the W1 / W3 ratio is 0.5 or more (W1 / W3≥0.5), the neck tends to bend in the thickness direction, leading to concerns about reduced operability in the oral cavity. In contrast, the toothbrush 100 of this embodiment has a D1 / D3 ratio greater than 0.3 (D1 / D3>0.3) and a W1 / W3 ratio less than 0.5 (W1 / W3<0.5), thus ensuring operability in the oral cavity while ensuring the bending point of the neck 20 is on the rear end side (the gripping part 30 side). Therefore, the toothbrush 100 can suppress the bending of the neck 20 in the thickness direction and reliably transmit the force of the gripping part 30 to the neck 20.

[0084] The difference between the length W2 of the head 10 in the width direction and the length W3 of the gripping part 30 in the width direction is within 2.0 mm.

[0085] In conventional toothbrushes, when the difference between the width length of the head and the width length of the handle is 2 mm or more, it is impossible to reliably brush with a surface when force is reliably applied to the handle. In contrast, in the toothbrush 100 of this embodiment, the difference between the width length W2 of the head 10 and the width length W3 of the handle 30 is within 2.0 mm, therefore, it is possible to reliably brush with a surface depending on the magnitude of the force applied to the handle 30 during brushing.

[0086] The lower limit of the difference between the thickness direction length D3 of the holding part 30 and the thickness direction length D1 of the neck 20 is preferably 4.0 mm or more. In addition, the upper limit of the difference between the above-mentioned length D3 and the above-mentioned length D1 is preferably 10.0 mm or less.

[0087] The lower limit of the difference between the width length W3 of the gripping part 30 and the width length W1 of the neck 20 is preferably 6.0 mm or more. Furthermore, the upper limit of the difference between the aforementioned length W3 and the aforementioned length W1 is preferably 12.0 mm or less.

[0088] The ratio of the thickness direction length D2 of the head 10 to the thickness direction length D3 of the holding portion 30, D2 / D3, is less than 0.4. The upper limit of the above-mentioned D2 / D3 is preferably 0.35 or less.

[0089] The lower limit of the difference between the thickness direction length D3 of the holding part 30 and the thickness direction length D2 of the head 10 is preferably 6.5 mm or more. Furthermore, the upper limit of the difference between the aforementioned length D3 and the aforementioned length D2 is preferably 13.0 mm or less.

[0090] Regarding the control section 30, such as Figure 13 , Figure 14 , Figure 15 As shown, in the cross-sectional shape of the grip portion 30, the angle R on the back side of the grip portion 30, i.e., the back side R portion 31, is preferably larger than the angle R on the surface side, i.e., the surface side R portion 32 (back side R portion > surface side R portion). That is, the radius of curvature of the R portion 31 is larger than the radius of curvature of the R portion 32. Therefore, regarding the toothbrush 100, the user can hold the grip portion 30 painlessly when holding it in a pen-like grip, and thus the force applied to the grip portion 30 can be reliably transmitted to the teeth in the vertical direction.

[0091] The gripping part 30 may have an anti-slip part 50 provided on at least a portion of its outer peripheral surface. For example... Figure 1 As shown, the anti-slip portion 50 can be constructed by arranging multiple wrinkled areas side-by-side in the long axis direction. The anti-slip portion 50 is preferably formed in the neck-side region (the front end side region of the grip portion 30) of the surface of the grip portion 30. Therefore, when the user grips the grip portion 30 with their palm, the anti-slip portion 50 abuts against the pad of the thumb, thus reliably gripping the grip portion 30 and reliably transmitting the force applied to the grip portion 30 to the teeth. It should be noted that there are no particular limitations regarding the shape, arrangement, or material of the anti-slip portion 50, as long as the structure provides an anti-slip function through contact with the fingers when the user grips the grip portion 30.

[0092] <Transition Section>

[0093] The front end of the transition portion 40 is adjacent to the base end of the neck 20, and the base end of the transition portion 40 is adjacent to the front end of the handle portion 30. The transition portion 40 connects the neck 20 and the handle portion 30 in the toothbrush 100. The length of the transition portion 40 in the width direction or the length in the thickness direction increases from the neck 20 toward the handle portion 30 in the long axis direction.

[0094] like Figure 9 As shown, the length L2 of the transition portion 40 in the major axis direction can be defined as the total length of the transition portion 40 in the X-axis direction. The lower limit of the aforementioned length L2 is preferably 5.0 mm or more. The upper limit of the aforementioned L2 is preferably 15.0 mm or less.

[0095] The ratio L2 of the length L2 along the major axis of the transition portion 40 to L1 of the length L1 along the major axis of the neck 20, L2 / L1, is less than 0.6. The lower limit of L2 / L1 is preferably 0.1 or more. The upper limit of L2 / L1 is preferably 0.5 or less.

[0096] In conventional toothbrushes, when the length of the neck along its long axis is shorter than that of the transition portion, the bending point of the neck moves towards the front end (head side), making the neck prone to flexing. In contrast, in the toothbrush 100 of this embodiment, the ratio of the length L2 of the transition portion 40 along its long axis to the length L1 of the neck 20 along its long axis, L2 / L1, is less than 0.6 (L2 / L1 < 0.6). Therefore, the bending point of the neck 20 of the toothbrush 100 can move towards the rear end (handle portion 30 side). Thus, the toothbrush 100 can minimize the flexing of the neck 20 in both the width and thickness directions, and can reliably transmit the force applied to the handle portion 30 to the head 10.

[0097] The transition portion 40 connects the various ridges formed in the area of ​​the neck 20 and the area formed in the grip portion 30, and its width and thickness increase from the front end toward the base end. In other words, the transition portion 40 has a third ridge 43 connecting the first ridge 21 formed in the neck 20 and the second ridge 33 formed in the grip portion 30. The first ridge 21 is the outline of the neck 20 in a top or front view. The second ridge 33 is the outline of the grip portion 30 in a top or front view.

[0098] The transition portion 40 increases in width or thickness from the front end toward the base end while connecting the respective edges (first edge 21, second edge 33) formed in the region of the neck 20 and the region of the gripping portion 30. This allows the neck 20 to bend only in either the thickness direction or the width direction, thereby suppressing torsion in the rotational direction.

[0099] Regarding transition section 40, such as Figure 10 As shown, in the front view, the radius of curvature of the first continuous surface 41 on the back side (bottom side) of the outer peripheral surface of the transition portion 40 is larger than the radius of curvature of the second continuous surface 42 on the surface side (planar side) of the outer peripheral surface of the transition portion 40. That is, the curvature of the second continuous surface 42 is more abrupt than that of the first continuous surface 41. Therefore, even when the length L2 of the transition portion 40 in the major axis direction is short, the toothbrush 100 can disperse stress concentration on the surface.

[0100] As described above, the toothbrush 100 of this embodiment has a brush body 110, which includes: a head 10 disposed at the front end in the long axis direction and having a bristle-embedded surface 11; a neck 20 disposed at a position further back than the head 10; and a handle 30 disposed at a position further back than the neck 20. The neck 20 is a straight line shape with a longitudinally elongated and flattened approximately quadrilateral cross-section. When the length in the thickness direction of the neck 20 is set as D1 and the length in the width direction is set as W1, the lengths D1 and W1 are constant values, and the lengths W1 and D1 extend along the long axis direction while satisfying the relationship D1 > W1.

[0101] With this structure, in the toothbrush 100 of this embodiment, the neck 20 is bent at the rear end side (the handle 30 side), making it less prone to bending. Therefore, while ensuring operability in the oral cavity and minimizing the bending of the neck 20 in the thickness and width directions, the force applied to the handle 30 is transmitted to the head 10 to achieve a reliable brushing sensation.

[0102] Symbol Explanation

[0103] 10: Head

[0104] 11: Hair transplanted surface

[0105] 12: Hair implantation pores

[0106] 13: hair bundle

[0107] 14: Brush Department

[0108] 15: Ribs

[0109] 16: The bottom of the head

[0110] 20: Neck

[0111] 21: First edge line

[0112] 30: Control Department

[0113] 31: Dorsal R-section

[0114] 32: Side R section

[0115] 33: Second ridge line

[0116] 40: Transition Section

[0117] 41: First Continuous Surface

[0118] 42: Second Continuous Surface

[0119] 43: Third ridge line

[0120] 50: Anti-slip section

[0121] 100: Toothbrush

[0122] 110: Refresh the main body

[0123] A1: Line segment connecting the midpoint of the thickness direction of the holding part

[0124] D1: Length of the neck in the thickness direction

[0125] D2: Minimum thickness of the head

[0126] D3: Maximum thickness of the gripping part

[0127] P1: The boundary between the head and neck

[0128] P2: Boundary between the neck and the transition area

[0129] P3: Boundary between the transition section and the holding section

[0130] L1: Length of the neck along its major axis

[0131] L2: Length of the transition section along its major axis

[0132] W1: Length of the neck in the width direction

[0133] W2: Maximum width of the head

[0134] W3: Maximum width of the holding part.

Claims

1. A toothbrush, characterized in that, The toothbrush has a brush body, which includes: a head disposed at the front end along its long axis and having a bristle-embedded surface; a neck disposed at the rear end of the head; and a handle disposed at the rear end of the neck. The neck is a straight line with a long, flat, roughly quadrilateral cross-section. When the length of the neck in the thickness direction is set as D1 and the length in the width direction is set as W1, the lengths D1 and W1 are constant values, and the lengths W1 and D1 extend along the major axis direction while satisfying the relationship D1 > W1.

2. The toothbrush according to claim 1, characterized in that, The ratio of the length W1 to the length D1 of the neck, W1 / D1, is less than 0.

8.

3. The toothbrush according to claim 1 or 2, characterized in that, The toothbrush has a transition section between the neck and the handle, the length of the transition section in both the width and thickness directions increasing from the neck toward the handle. When the length of the neck along its major axis is set as L1 and the length of the transition portion along its major axis is set as L2, the ratio of the length L2 to the length L1, L2 / L1, is less than 0.

6.

4. The toothbrush according to claim 1, characterized in that, The length D2, which constitutes the minimum thickness of the head, is 2.0 mm or more and 3.5 mm or less. The ratio of length D2 to length D1, D2 / D1, is less than 0.

8. The length W2, which becomes the maximum width of the head, is 10.0 mm or more and 15.0 mm or less. The ratio of the length W1 to the length W2, W1 / W2, is less than 0.

4.

5. The toothbrush according to claim 1, characterized in that, The gripping portion is a straight line shape with a roughly quadrilateral cross-section. When the length that will become the maximum thickness of the gripping portion is set to D3, and the length that will become the maximum width of the gripping portion is set to W3, the lengths D3 and W3 are constant values. Furthermore, the surface of the gripping portion extends in a constant shape along its long axis, parallel to the flocked surface. The ratio of length D3 to length D1, D1 / D3, is greater than 0.

3. The ratio of length W1 to length W3, W1 / W3, is less than 0.

5. The toothbrush has a transition section between the neck and the handle, the length of the transition section in both the width and thickness directions increasing from the neck toward the handle. The transition portion connects the ridge lines formed in the area of ​​the neck and the area formed in the gripping portion, and the width and thickness of the transition portion increase from the front end toward the base end.

6. The toothbrush according to claim 1, characterized in that, The difference between the length W2, which is the maximum width of the head, and the length W3, which is the maximum width of the gripping part, is within 2.0 mm.

7. The toothbrush according to claim 1, characterized in that, The brush body is formed from only one type of hard resin.

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