toothbrush

Abstract

The present invention makes it possible to improve the material recyclability of a toothbrush and provide multiple types of toothbrushes by adopting a configuration in which a handle part and a brush part can be connected and separated, and also provides a toothbrush that can suppress decreases in usability that occur when brushing teeth via a configuration in which a handle part and a brush part can be connected and separated.　A toothbrush 10 comprises a handle part 100, a brush part 200, and a seal mechanism 300. The handle part 100 comprises: a handle body 110 configured so as to be graspable and in which a hollow internal space 113 is formed; and a handle-side neck section 120 disposed further toward a longitudinal tip-end side than the handle body, and in which is formed a hollow opening part 130 that communicates with the internal space. The brush part 200 comprises: a head section 210 in which bristle bundles 211 have been implanted; and a brush-side neck section 220 extending, from the head section, toward a base end in the longitudinal direction, and in which has been formed a connection part 230 that can connect with and separate from the opening part. The seal mechanism 300 maintains the airtightness of the internal space in a state in which the opening part and the connection part are connected. The brush-side neck section has a closed structure in which a space that causes the outside and the inside of the head section to communicate is not formed.

Description

[Technical Field]

[0001] The present invention relates to a toothbrush. [Background technology]

[0002] The oral conditions of toothbrush users vary widely, and toothbrush design preferences are also diverse. However, providing toothbrushes tailored to each individual user would significantly reduce productivity and increase costs. Furthermore, companies are now being asked to become more environmentally conscious in response to issues such as microplastics and global warming. Against this backdrop, toothbrushes are largely made of resin materials, and because they are made up of a combination of many different resin materials, their material recyclability is extremely poor. Therefore, there has been a demand in recent years for a fundamental improvement in the material recyclability of toothbrushes.

[0003] For example, Patent Document 1 discloses a toothbrush that includes a handle portion having an internal space filled with a medicinal solution and a brush portion having bristle bundles planted therein and configured to be connectable and detachable to the handle portion. A flow path is formed inside the brush portion that communicates with the internal space of the handle portion when the handle portion and the brush portion are connected. Furthermore, this flow path communicates with the outside of the brush portion via bristle planting holes in the brush portion.

[0004] The toothbrush of Patent Document 1 allows a user to crush and deform the handle by grasping and pressing the handle with their fingers, etc. When the handle is crushed and deformed, the medicinal solution filled in the internal space moves into the brush part.

[0005] When the handle and brush are configured to be connectable and detachable, as in the toothbrush of Patent Document 1, the handle and brush can be collected separately, or various types of handles and brushes can be selected and used in any combination. Therefore, the toothbrush of Patent Document 1 is highly recyclable, and it is thought that it is possible to provide a wide variety of toothbrushes. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-13375 Summary of the Invention [Problem to be solved by the invention]

[0007] However, as mentioned above, the toothbrush of Patent Document 1 has the problem that the handle is crushed and deformed when the user grips it, making it difficult to use when brushing teeth. To address this problem, if it were possible to maintain the airtightness of the internal space of the handle when the handle and brush head are connected, it would be possible to prevent the handle from easily deforming when the user grips it.

[0008] However, as mentioned above, the toothbrush of Patent Document 1 has a flow path formed inside the brush head that communicates with the bristle holes so that the medicinal solution can be delivered to the brush head. Therefore, with the toothbrush of Patent Document 1, the internal space of the handle head cannot be kept airtight when the brush head and handle head are connected. Therefore, when using the toothbrush of Patent Document 1 to brush teeth, it is difficult to avoid a decrease in usability caused by the easy deformation of the handle head.

[0009] Furthermore, when the handle and brush parts are configured to be connectable and detachable, as in the toothbrush of Patent Document 1, and the handle part is configured to be hollow, it is thought that the material recyclability of the toothbrush can be further improved by making the handle part thinner.

[0010] However, in the toothbrush of Patent Document 1, if the handle is formed thin, the handle becomes even more easily deformed. Therefore, in the toothbrush of Patent Document 1, if the handle is formed thin, usability when brushing teeth is significantly reduced. Therefore, with the toothbrush of Patent Document 1, it is difficult to significantly improve the material recyclability of the toothbrush while suppressing the reduction in usability when brushing teeth.

[0011] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a toothbrush that improves the material recyclability of toothbrushes and enables the provision of a wide variety of toothbrushes by configuring the handle portion and brush portion to be connectable and detachable, while also preventing the reduction in usability when brushing teeth that occurs when the handle portion and brush portion are configured to be connectable and detachable. [Means for solving the problem]

[0012] In order to achieve the above object, the toothbrush of the present invention has a handle portion including a handle body having a hollow internal space formed therein and configured to be grippable, and a handle-side neck portion that is positioned longitudinally distal to the handle body and has a hollow mouth portion formed therein that communicates with the internal space, a brush portion including a head portion having tufts of bristles implanted therein, and a brush-side neck portion that extends longitudinally from the head portion toward the base end and has a connecting portion formed therein that can be connected to and separated from the mouth portion, and a sealing mechanism that maintains the airtightness of the internal space when the mouth portion and the connecting portion are connected, and the brush-side neck portion has a closed structure in which no space communicating between the inside and outside of the head portion is formed. The outer diameter of the mouth portion is smaller than the outer diameter of the handle body, the handle side neck portion is formed longitudinally closer to the base end than the mouth portion and has a shoulder portion whose outer diameter gradually increases from the mouth portion side toward the handle body side, the connection portion has an insertion portion into which the mouth portion and shoulder portion can be inserted, and the sealing mechanism is composed of a fitting portion that maintains the airtightness of the internal space by fitting the brush side neck portion and the handle side neck portion together as the mouth portion and shoulder portion are inserted into the insertion portion. [Effects of the Invention]

[0013] In the invention having the above configuration, the handle and head are connectable and separable, which improves material recyclability and enables the provision of a wide variety of toothbrushes. Furthermore, when the handle and head are connected, the internal space of the handle body can be maintained airtight, thereby increasing the strength of the handle body. This prevents the handle body from accidentally deforming while the user is holding it and brushing their teeth. This reduces the deterioration in usability that accompanies handle body deformation during toothbrushing. Furthermore, because the toothbrush of the present invention can increase the strength of the handle body, the handle body can be made even thinner. This further improves material recyclability. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a partial cross-sectional view showing a toothbrush according to an embodiment of the present invention. [Figure 2] 2 is an enlarged view of a portion 2A surrounded by a dashed line in FIG. 1. FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along the line 3A-3A of FIG. 2. [Figure 4] 10A to 10C are partial cross-sectional views showing an example of an operation procedure for separating the handle portion and the brush portion. [Figure 5] 10A to 10C are partial cross-sectional views showing an example of an operation procedure for separating the handle portion and the brush portion. [Figure 6] FIG. 10 is a partial cross-sectional view showing a part of a toothbrush according to a first modified example. [Figure 7] FIG. 10 is a partial cross-sectional view showing a part of a toothbrush according to a second modification. [Figure 8] FIG. 10 is a partial cross-sectional view showing a part of a toothbrush according to a second modification. [Figure 9] FIG. 10 is a partial cross-sectional view showing a toothbrush according to a third modification. [Figure 10] FIG. 10 is a partial cross-sectional view showing a toothbrush according to a third modification. [Figure 11] FIG. 10 is a partial cross-sectional view showing a toothbrush according to a third modification. [Figure 12] FIG. 10 is a partial cross-sectional view showing a part of a toothbrush according to a fourth modification. [Figure 13] FIG. 10 is a partial cross-sectional view showing a part of a toothbrush according to a fourth modification. [Figure 14] FIG. 10 is a partial cross-sectional view showing a part of a toothbrush according to a fourth modification. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that the dimensional proportions in the drawings are exaggerated for the sake of explanation and differ from the actual proportions.

[0016] 1 to 3 are diagrams showing the configuration of each part of the toothbrush 10 according to the embodiment. Figures 4 and 5 are diagrams showing an example of the operating procedure when the handle unit 100 and the brush unit 200 are separated.

[0017] Arrow X1 in each drawing indicates the tip side of toothbrush 10, and arrow X2 indicates the base side of toothbrush 10. The tip side and base side of handle portion 100 and brush head 200 are in the same direction as toothbrush 10. In the drawings, the central axis of toothbrush 10 is indicated by dashed dotted line c1.

[0018] <Toothbrush> As shown in FIG. 1, the toothbrush 10 includes a handle portion 100, a brush portion 200, and a sealing mechanism 300.

[0019] The toothbrush 10 can be used to clean the inside of a user's (natural person's) mouth. When using the toothbrush 10, the user can connect the handle portion 100 and the brush portion 200 as shown in Fig. 1. When the handle portion 100 and the brush portion 200 are connected, a sealing mechanism 300 is formed in the connection area between the handle portion 100 and the brush portion 200.

[0020] <Handle section> As shown in Figures 1 and 2, the handle portion 100 comprises a handle body 110 having a hollow internal space 113 formed therein and configured to be grippable, and a handle-side neck portion 120 that is positioned longitudinally further towards the tip side than the handle body 110 and has a hollow mouth portion 130 that communicates with the internal space 113.

[0021] As shown in Figure 1, handle body 110 is hollow. Therefore, toothbrush 10 can be manufactured using less resin than a handle body having a solid structure filled with resin.

[0022] The handle body 110 has a cylindrical shape with approximately the same outer diameter and approximately the same cross-sectional area over its entire length in the longitudinal direction. A recess can be formed in the base end surface (bottom surface) of the handle body 110, recessed toward the tip side of the handle body 110.

[0023] The outer diameter D1 of the handle body 110 (see FIG. 1) can be, for example, 8.4 mm or more and 50 mm or less. From the viewpoint of reducing the amount of resin in the handle body 110 while maintaining ease of use when the user brushes their teeth, the outer diameter D1 of the handle body 110 is preferably, for example, 10 mm or more and 40 mm or less, and more preferably 15 mm or more and 30 mm or less.

[0024] The outer diameter of a typical toothbrush handle is approximately 10 mm. However, considering usability for children, the elderly, and physically disabled, it is preferable to make the outer diameter of the handle as large as possible. For this reason, various tools are commercially available that can be attached to toothbrush handles (grip) to increase the outer diameter of the handle. For example, if a handle is manufactured using conventional injection molding to increase the diameter, the amount of resin used in manufacturing increases, resulting in issues such as increased weight, sink marks, and extended molding time. On the other hand, as described below, if the hollow handle body 110 is manufactured using blow molding, the amount of resin used in manufacturing the handle body 110 can be reduced while maintaining the strength of the handle body 110. This reduces the weight of the handle body 110, shortens the molding time, and prevents deterioration of the design and appearance due to sink marks. Furthermore, the handle body 110 can be more easily made larger in diameter than the handle body of the typical toothbrush exemplified above. Furthermore, reducing the amount of resin also reduces the environmental impact and costs.

[0025] The length L1 (see FIG. 1) of the handle body 110 along the longitudinal direction can be, for example, 50 mm or more and 150 mm or less. Furthermore, from the viewpoint of preventing the handle body 110 from being formed excessively long and the amount of resin in the handle body 110 from being unnecessarily large, the length L1 of the handle body 110 along the longitudinal direction is, for example, preferably 70 mm or more and 140 mm or less, and more preferably 90 mm or more and 120 mm or less.

[0026] The starting point and ending point serving as the measurement reference for the length L1 along the longitudinal direction of the handle body 110 are the tip and base ends of the handle body 110. The tip of the handle body 110 is located at the boundary between the handle body 110 and the shoulder 140. In the front view shown in FIG. 1, this boundary is the position where the curve or straight line where the outer diameter (width) expands from the shoulder 140 side to the handle body 110 side converges and the curvature changes, or the angle changes (to become parallel to the central axis c1). Note that the measurement reference for L1 can also be similarly applied to each modified example described later (for example, the modified example shown in FIG. 9). Furthermore, if the tip of the handle body 110 has an asymmetric shape in the circumferential direction (such as an asymmetric shape in the cross-sectional view shown in FIG. 2), the tip-side boundary serving as the reference for the length L1 along the longitudinal direction of the handle body 110 can be defined as the position where the measured length L1 is longest.

[0027] The thickness t1 of the handle body 110 (see FIG. 1) can be, for example, 0.25 mm or more and 2.5 mm or less. From the viewpoint of effectively reducing the amount of resin in the handle body 110 while preventing the strength of the handle body 110 from becoming excessively weak, the thickness t1 of the handle body 110 is preferably, for example, 0.40 mm or more and 1.5 mm or less, and more preferably 0.50 mm or more and 1.25 mm or less. The thickness t1 of the handle body 110 exemplified above is the dimension at the thinnest part of the handle body 110.

[0028] In this embodiment, the handle portion 100, which is composed of the handle body 110 and the handle-side neck portion 120, can be manufactured as a single unit by, for example, stretch blow molding. By employing stretch blow molding to manufacture the handle portion 100, it is possible to improve dimensional accuracy compared to the case of employing a general direct blow molding method, and it is also possible to omit post-processing such as deburring. Furthermore, by employing stretch blow molding, it is possible to improve product strength by utilizing the high stretching effect of the parison, and therefore, even if the handle portion 100 is manufactured to be thin, it is possible to prevent the handle portion 100 from being crushed when gripped by a user.

[0029] The manufacturing method of the handle portion 100 is not limited to the stretch blow molding method, and it can also be manufactured by, for example, injection blow molding. Even when injection blow molding is used, it is possible to improve the product strength of the handle portion 100, just as when stretch blow molding is used.

[0030] When the handle portion 100 is manufactured by a blow molding method (stretch blow molding or injection blow molding), a cold parison method (two-stage method) can be used to improve production efficiency. However, the handle portion 100 can also be manufactured by a hot parison method (one-stage method).

[0031] The resin material used to manufacture the handle portion 100 is not particularly limited as long as it is a material to which the blow molding method can be applied, but is preferably a resin material whose main component is polyethylene, polypropylene, polyethylene terephthalate, polylactic acid, polyhydroxybutyrate, or polystyrene. Furthermore, the resin material used to manufacture the handle portion 100 is more preferably a resin material whose main component is polyethylene terephthalate. When a resin material whose main component is polyethylene terephthalate is used, the difference in specific gravity between the material constituting the head portion 210 (described below) becomes clear, allowing users to easily separate the handle portion 100 and the head portion 210. Furthermore, it becomes possible to utilize existing recycling systems that separate materials based on their specific gravity.

[0032] The handle body 110 may be printed or colored. However, from the viewpoint of recyclability, it is more preferable to manufacture the handle body 110 colorless.

[0033] To improve the design of the handle body 110, the internal space 113 can be filled with a solid material such as resin or paper, a semi-solid material such as gel, or a colored liquid. The solid or semi-solid material filled in the internal space 113 is preferably one that can be easily separated from the handle body 110. For example, it is preferable to use spherical beads or strip-shaped films.

[0034] Furthermore, a more preferable method for improving the design of the handle body 110 is to place a shrink label on the outer surface of the handle body 110. When the handle body 110 is decorated with a shrink label, the handle body 110 and the shrink label can be easily separated, improving material recyclability. The contact angle of the surface of the shrink label with respect to the outer surface of the handle body 110 is more preferably, for example, 60° or more. A contact angle of 60° or more can suppress slippage of the toothbrush and prevent water from penetrating the gap between the handle body 110 and the shrink label. Furthermore, it is preferable that the shrink label be antibacterial-treated to suppress bacterial growth.

[0035] As shown in FIGS. 1 and 2, the handle-side neck portion 120 is formed integrally with the handle body 110 and extends toward the tip end of the handle body 110.

[0036] The mouth portion 130 has a hollow structure similar to the handle body 110. Inside the mouth portion 130, a hollow portion 133 that communicates with the internal space 113 of the handle body 110 is formed.

[0037] The mouth portion 130 is disposed at the tip of the handle portion 100. A tip opening 131 is formed at the tip of the mouth portion 130.

[0038] The outer diameter D2 (see FIG. 2) of the mouth portion 130 is smaller than the outer diameter D1 (see FIG. 1) of the handle body 110. Note that, when the first recess 135 is formed in the mouth portion 130, the outer diameter D2 of the mouth portion 130 is the outer diameter of the portion other than the location where the first recess 135 is formed.

[0039] The outer diameter D2 of the mouth portion 130 can be, for example, 7.0 mm or more and 14.0 mm or less. Furthermore, taking into consideration the outer diameter D1 of the handle body 110 and the amount of stretching during molding when stretch blow molding is employed, the outer diameter D2 of the mouth portion 130 is preferably, for example, 8.0 mm or more and 13.0 mm or less, and more preferably 9.0 mm or more and 12.0 mm or less.

[0040] In toothbrush 10 according to this embodiment, the ratio (D1 / D2) of the outer diameter (D1) of handle body 110 to the outer diameter (D2) of mouth portion 130 can be set to 1.2 or more and 10 or less for the following reasons.

[0041] A large outer diameter ratio (D1 / D2) in toothbrush 10 indicates that more resin remains on the mouth portion 130 side during blow molding and that the resin is stretched further on the handle body 110 side. Therefore, it can be understood that the larger the outer diameter ratio (D1 / D2) of toothbrush 10, the thinner the handle body 110 is formed, and the amount of resin in the handle body 110 is accordingly reduced. On the other hand, if the outer diameter ratio (D1 / D2) is excessively large, the thinner the handle body 110 becomes, resulting in a significant decrease in the strength of the handle body 110. However, when blow molding is used, the strength of the handle body 110 can be improved by orienting the resin during stretching. Taking this into consideration, the outer diameter ratio (D1 / D2) is preferably 1.2 or greater and 10 or less, and more preferably 1.6 or greater and 6 or less.

[0042] When toothbrush 10 has an outer diameter ratio (D1 / D2) of 1.2 or more and 10 or less, outer diameter D1 of handle body 110 is preferably, for example, 20 mm, and outer diameter D2 of mouth portion 130 is preferably, for example, 8 mm.

[0043] The length L2 (see FIG. 1) along the longitudinal direction of the mouth portion 130 can be, for example, 5 mm or more and 20 mm or less. Furthermore, from the viewpoint of preventing breakage or the like around the mouth portion 130 due to the influence of the moment acting on the mouth portion 130 when brushing teeth, the length L2 along the longitudinal direction of the mouth portion 130 is, for example, preferably 5 mm or more and 16 mm or less, and more preferably 5 mm or more and 12 mm or less.

[0044] The starting point and ending point serving as the measurement reference for the length L2 of the mouth 130 along the longitudinal direction are the tip and base ends of the mouth 130. The base end of the mouth 130 is located at the boundary between the mouth 130 and the shoulder 140. In the front view shown in FIG. 1, this boundary is the position where the outer diameter (width) narrows from the curve or straight line from the shoulder 140 side to the mouth 130 side, and the narrowing diameter converges, changing the curvature, or the position where the angle changes (to become parallel to the central axis c1). Note that the measurement reference for L2 can also be similarly applied to each modified example described later (for example, the modified example shown in FIG. 9). Furthermore, when the mouth 130 has an asymmetric shape near its base end in the circumferential direction (such as an asymmetric shape in the cross-sectional view shown in FIG. 2), the base-side boundary serving as the reference for the length L2 along the longitudinal direction of the mouth 130 can be defined as the position where the measured length L2 is shortest.

[0045] In toothbrush 10 according to this embodiment, the length ratio (L1 / L2) of the length (L1) of handle body 110 along the longitudinal direction to the length (L2) of mouth portion 130 along the longitudinal direction can be set to 2.5 or more and 30 or less for the following reasons.

[0046] As shown in FIGS. 1 and 2 , when brushing teeth with the mouth portion 130 connected to the brush-side neck portion 220, the handle portion 100 is supported by the brush-side neck portion 220 via the mouth portion 130. Considering the load on the mouth portion 130, it is preferable that the mouth portion 130 have a length greater than or equal to a predetermined length. In particular, if the handle body 110 is formed long, the moment acting on the mouth portion 130 during toothbrushing also increases, making it necessary to form the mouth portion 130 long as a countermeasure. On the other hand, if the mouth portion 130 is formed excessively long, the handle portion 100 will be formed long, and the overall length of the toothbrush 10 will also increase. This will reduce the operability of the toothbrush 10 when brushing teeth. Furthermore, as the overall length of the toothbrush 10 increases, the amount of resin used in the toothbrush 10 will also increase. For these reasons, the length ratio (L1 / L2) is preferably 2.5 to 30, and more preferably 7.5 to 25.

[0047] When the length ratio (L1 / L2) of toothbrush 10 is 2.5 or more and 30 or less, the length L1 along the longitudinal direction of handle body 110 is preferably, for example, 120 mm, and the length L2 along the longitudinal direction of mouth portion 130 is preferably, for example, 8 mm.

[0048] The thickness t2 of the mouth portion 130 (see FIG. 2) can be, for example, 0.8 mm or more and 3 mm or less. Furthermore, from the viewpoint of preventing easy deformation of the mouth portion 130 when brushing teeth with the mouth portion 130 connected to the brush-side neck portion 220, the thickness t2 of the mouth portion 130 is, for example, preferably 0.9 mm or more and 2.5 mm or less, and more preferably 1.0 mm or more and 2.0 mm or less. Note that, when a first recess 135 is formed in the mouth portion 130, the thickness t2 of the mouth portion 130 refers to the thickness of the portion other than the location where the first recess 135 is formed.

[0049] As shown in FIG. 2, the outer peripheral surface of the mouth portion 130 may be formed with a first recess 135 recessed radially inward of the mouth portion 130 (in the same direction as the central axis c1 side).

[0050] The first recess 135 has a semicircular cross section and is formed near the approximate center position in the longitudinal direction of the mouth portion 130. The first recess 135 is formed along the entire outer periphery of the outer surface of the mouth portion 130.

[0051] The height of first recess 135 (corresponding to the thickness of opening 130 at first recess 135) is preferably, for example, 0.3 mm to 2.0 mm. When first recess 135 is formed with a height in this range, as shown in Fig. 2, when second protrusion 235 formed on inner cylinder 240 is placed in first recess 135, the engagement between first recess 135 and second protrusion 235 effectively prevents handle-side neck 120 and brush-side neck 220 from accidentally separating.

[0052] The positions at which the first recesses 135 are formed, the cross-sectional shape of the first recesses 135, the number of first recesses 135, etc. are not particularly limited and can be changed as appropriate. Furthermore, the mouth portion 130 may be provided with, for example, first protrusions that protrude radially outward from the mouth portion 130. The shape, position, number, etc. of the first protrusions are also not particularly limited. Furthermore, the mouth portion 130 may be provided with only the first recesses 135, only the first protrusions, or both the first recesses 135 and the first protrusions.

[0053] As shown in FIG. 1, the handle-side neck portion 120 has a shoulder portion 140 formed on the base end side of the mouth portion 130 in the longitudinal direction.

[0054] The outer diameter of shoulder portion 140 gradually increases from the mouth portion 130 side toward the handle body 110 side. Shoulder portion 140 has a hollow structure that communicates between a hollow portion 133 of mouth portion 130 located on the tip side of shoulder portion 140 and the internal space 113 of handle body 110.

[0055] 1, shoulder portion 140 has a curved shape in which the outer diameter gradually increases from the mouth portion 130 side toward the handle body 110 side. However, for example, shoulder portion 140 may be formed in a linear shape in which the outer diameter gradually increases from the mouth portion 130 side toward the handle body 110 side. Also, handle portion 100 may have a structure without shoulder portion 140. In such a configuration, handle portion 100 can be configured to be connectable to brush-side neck portion 220 via mouth portion 130.

[0056] The total length of the handle portion 100 along the longitudinal direction (the combined length of the handle body 110 and the handle-side neck portion 120) can be formed to be, for example, 55 mm or more and 180 mm or less.

[0057] <Brush section> As shown in Figures 1 and 2, the brush part 200 comprises a head part 210 in which bristle bundles 211 are implanted, and a brush-side neck part 220 that extends from the head part 210 toward the base end in the longitudinal direction and has a connection part 230 that can be connected and separated from the mouth part 130.

[0058] The connecting portion 230 is formed at the base end of the brush portion 200 (the base end of the brush-side neck portion 220).

[0059] 2, the connecting part 230 has an insertion part 231 into which the mouth part 130 and the shoulder part 140 can be inserted. In this embodiment, the insertion part 231 is formed by a space partitioned on the inner circumferential side of the inner cylindrical part 240 and the outer cylindrical part 250 provided in the connecting part 230.

[0060] Brush-side neck portion 220 has a closed structure in which no space is formed that connects the inside and outside of head portion 210. Specifically, as shown in Fig. 2, connecting portion 230 of brush-side neck portion 220 has tip surface 232 that blocks communication between the inside of brush-side neck portion 220 and hollow insertion portion 231 that faces the outside of brush-side neck portion 220. Therefore, no space, passage, hole, etc. is formed inside brush-side neck portion 220 that connects the inside of head portion 210 with the outside of head portion 210.

[0061] As shown in FIGS. 2 and 3, the connecting portion 230 has an inner cylindrical portion 240 and an outer cylindrical portion 250 arranged to cover the inner cylindrical portion 240 with a gap g between them.

[0062] The connecting portion 230 formed at the base end of the brush-side neck portion 220 is shaped to form two cylindrical portions. Of the two cylindrical portions, the portion located on the inner periphery of the connecting portion 230 constitutes the inner cylinder portion 240, and the portion located on the outer periphery of the inner cylinder portion 240 constitutes the outer cylinder portion 250.

[0063] The connecting portion 230 does not have to be formed as a double-tube structure consisting of the inner tubular portion 240 and the outer tubular portion 250. For example, the connecting portion 230 may be formed as a recess defined on the inner circumferential side, where a single space into which the mouth portion 130 and the shoulder portion 140 can be inserted.

[0064] As shown in FIG. 2, the connecting portion 230 is formed with a second protrusion 235 that abuts against the outer peripheral surface of the first recess 135 when the mouth portion 130 and the shoulder portion 140 are inserted into the insertion portion 231.

[0065] The second protrusion 235 is provided on the inner circumferential surface of the inner cylindrical portion 240 that constitutes the connecting portion 230. The second protrusion 235 protrudes radially inward (in the same direction as the central axis c1 side) of the connecting portion 230. The second protrusion 235 has a semicircular cross-sectional shape that matches the shape of the first recess 135.

[0066] The second protrusion 235 is formed at a position corresponding to the position where the first recess 135 is formed. Moreover, the second protrusion 235 is formed along the entire circumference of the inner circumferential surface of the inner cylinder portion 240. Therefore, when the mouth portion 130 and the shoulder portion 140 are inserted into the insertion portion 231, the second protrusion 235 abuts against the outer circumferential surface of the first recess 135 over the entire circumference.

[0067] The height of the second convex portion 235 (corresponding to the thickness of the inner cylindrical portion 240 at the second convex portion 235) is preferably, for example, 0.3 mm or more and 2.0 mm or less, similar to the first concave portion 135.

[0068] The position at which the second convex portion 235 is formed, the cross-sectional shape of the second convex portion 235, the number of second convex portions 235, etc. can be changed as appropriate to correspond to the first concave portion 135. For example, when only the first concave portion 135 is formed in the mouth portion 130, only the second convex portion 235 can be formed in the connecting portion 230. Furthermore, when the first concave portion 135 and the first convex portion are formed in the mouth portion 130, the second convex portion 235 and a second concave portion that can abut against the first convex portion can be formed in the connecting portion 230.

[0069] The thickness ta (see FIG. 2) of the inner cylindrical portion 240 can be formed to be, for example, 0.3 mm or more and 1.5 mm or less from the viewpoint of inducing deflection of the inner cylindrical portion 240 with an appropriate amount of deformation when the mouth portion 130 and the shoulder portion 140 are inserted into the insertion portion 231. The thickness ta of the inner cylindrical portion 240 is, for example, preferably 0.4 mm or more and 1.3 mm or less, and more preferably 0.6 mm or more and 1.1 mm or less. Note that the thickness ta exemplified above is the dimension at the thinnest portion of the inner cylindrical portion 240, and in this embodiment is the thickness near the base end of the inner cylindrical portion 240.

[0070] The thickness tb (see FIG. 2) of the outer cylinder portion 250 can be formed to be, for example, 1 mm or more and 2 mm or less from the viewpoint of protecting the mouth portion 130 and the inner cylinder portion 240 from the outside when the mouth portion 130 is inserted into the insertion portion 231 and ensuring sealing performance at the connection portion 230. The thickness tb of the outer cylinder portion 250 is, for example, preferably 0.6 mm or more and 2.5 mm or less, and more preferably 0.8 mm or more and 1.8 mm or less. Note that the thickness tb exemplified above is the dimension at the thinnest portion of the outer cylinder portion 250, and in this embodiment is the thickness near the base end of the outer cylinder portion 250.

[0071] In the toothbrush 10 according to this embodiment, the thickness ratio (ta / tb) of the thickness ta of the inner cylinder 240 to the thickness tb of the outer cylinder 250 is preferably 0.15 or more and 1.5 or less for the following reasons.

[0072] When the mouth portion 130 and the shoulder portion 140 are inserted into the insertion portion 231, the toothbrush 10 deforms so as to be pushed open, thereby improving the ease of insertion of the mouth portion 130 and the shoulder portion 140. For this reason, it is undesirable to form the thickness ta of the inner tube portion 240 to be excessively large. Furthermore, from the viewpoint of protecting the mouth portion 130 and the inner tube portion 240 from the outside and ensuring a seal at the connection portion 230, it is undesirable for the outer tube portion 250 to be configured to be easily deformable like the inner tube portion 240. For the reasons described above, it is undesirable to form the thickness tb of the outer tube portion 250 to be excessively smaller than the thickness ta of the inner tube portion 240, and the thickness ratio (ta / tb) is preferably 0.15 or more and 1.5 or less, and more preferably 0.3 or more and 1.0 or less.

[0073] The distance tc (see Figure 3) of the gap g formed between the inner tube portion 240 and the outer tube portion 250 is preferably formed to be, for example, 1 mm or more and 3 mm or less, from the viewpoint of promoting deformation of the outer tube portion 250 during the pressing operation described below and making it easier to separate the connection portion 230 from the mouth portion 130 and shoulder portion 140.

[0074] The material constituting the brush unit 200 is not particularly limited, but examples thereof include polypropylene, polyethylene, polyethylene terephthalate, polybutylene terephthalate, polyacetal, polystyrene, nylon, and acrylonitrile-styrene resin. Polypropylene and polyethylene are particularly preferred resins constituting the brush unit 200. Furthermore, when the head unit 210 is manufactured by integral molding, the bristles constituting the bristle bundles 211 are preferably not bristles but elastomers with high hardness, particularly polyamide, polyester, polystyrene, polyurethane, and silicone resin. Furthermore, when the bristle bundles 211 and the head unit 210 are manufactured by integral molding, the bristles constituting the bristle bundles 211 are more preferably thermoplastic polyurethanes with an A hardness of 40 or higher.

[0075] The head portion 210 may have a structure in which the bristle bundles 211 are implanted by, for example, flat-line implantation or anchorless (anchor-free) implantation, or may have a structure in which the bristle bundles 211 are formed by integral molding with the head portion 210 as described above. When the bristles constituting the bristle bundles 211 are not formed by integral molding with the head portion 210, they can be made of known materials such as nylon, polybutylene terephthalate, or polyethylene terephthalate.

[0076] There are no particular limitations on the shape and size of the head portion 210, the material of the bristles that make up the bristle bundles 211, the number of bristles planted, the planted area, the outer diameter, etc., and any known structure can be used as appropriate.

[0077] The resin material constituting brush-side neck portion 220 is preferably hard. By selecting such a resin material, when a structure is adopted in which handle portion 100 and brush portion 200 are connected with connecting portion 230 covering mouth portion 130, as in toothbrush 10 of the present embodiment, the outer circumferential surface of mouth portion 130 can be covered with hard resin. This prevents inadvertent deformation of connecting portion 230 when handle portion 100 and brush portion 200 are connected, and effectively prevents a decrease in the airtightness of internal space 113 of handle body 110. As a combination of resin materials that will produce the above-mentioned effects, for example, polyethylene, polypropylene, and polyethylene terephthalate can be used as the resin material for the handle portion 100, and polyacetal, polybutylene terephthalate, PCTA (a resin composed of a dicarboxylic acid component whose main components are terephthalic acid and isophthalic acid, and a diol component whose main component is 1,4-cyclohexanedimethanoldiol), polyethylene terephthalate, acrylonitrile styrene, polypropylene, and polyethylene can be used as the resin material for the brush side neck portion 220.

[0078] <Sealing mechanism> As shown in FIG. 2, the toothbrush 10 has a sealing mechanism 300 that maintains the airtightness of the internal space 113 of the handle body 110 when the mouth portion 130 and the connecting portion 230 are connected.

[0079] The sealing mechanism 300 is composed of a fitting portion 310 that maintains the airtightness of the internal space 113 of the handle body 110 by fitting the handle side neck portion 120 and the brush side neck portion 220 together as the mouth portion 130 and shoulder portion 140 are inserted into the insertion portion 231.

[0080] When using toothbrush 10, a user can connect handle portion 100 and brush portion 200 by the simple operation of inserting mouth portion 130 and shoulder portion 140 into insertion portion 231. Furthermore, by connecting handle portion 100 and brush portion 200, the user can maintain the airtightness of internal space 113 of handle body 110 by means of seal mechanism 300 formed in the connection area between handle portion 100 and brush portion 200.

[0081] The fitting portion 310 partially brings the mouth portion 130 and the connecting portion 230 into tight contact with each other as the mouth portion 130 and the shoulder portion 140 of the handle-side neck portion 120 are inserted into the insertion portion 231 of the connecting portion 230 of the brush-side neck portion 220. The toothbrush 10 seals the periphery of the mouth portion 130 and the shoulder portion 140 through the fitting by the fitting portion 310. In the toothbrush 10, the first recessed portion 135 and the second protruding portion 235, the distal end surface 132 of the mouth portion 130 and the distal end surface 232 of the connecting portion 230, and the shoulder portion 140 and the base end surfaces 242, 252 of the tubular portions 240, 250 all cooperate to form the fitting portion 310.

[0082] The specific structure of the sealing mechanism 300 (fitting portion 310) is not limited as long as it can exhibit a sealing property capable of maintaining the airtightness of the internal space 113 of the handle body 110 when the handle-side neck portion 120 and the brush-side neck portion 220 are mechanically connected. For example, the sealing mechanism 300 may be configured to maintain the airtightness of the internal space 113 of the handle body 110 by having the outer circumferential surface of the mouth portion 130 come into close contact with the inner circumferential surface of the inner cylindrical portion 240 over the entire longitudinal length. Furthermore, for example, the sealing mechanism 300 may be configured to maintain the airtightness of the internal space 113 of the handle body 110 by threading a threaded portion formed on the outer circumferential surface of the mouth portion 130 into a threaded portion formed on the inner circumferential surface of the inner cylindrical portion 240 that constitutes the connecting portion 230.

[0083] 2, when the mouth portion 130 and the shoulder portion 140 are inserted into the insertion portion 231, the tip surface 132 of the mouth portion 130 abuts against the tip surface 232 of the connecting portion 230 located on the tip side of the insertion portion 231. Therefore, when the handle side neck portion 120 and the brush side neck portion 220 are connected, the tip surface 132 of the mouth portion 130 and the tip surface 232 of the connecting portion 230 are in close contact with each other, thereby improving the sealing performance of the sealing mechanism 300.

[0084] 2, the base end surface 242 of the inner cylinder 240 and the base end surface 252 of the outer cylinder 250 abut against the shoulder 140 when the mouth 130 and the shoulder 140 are inserted into the insertion portion 231. Therefore, when the handle-side neck 120 and the brush-side neck 220 are connected, the base end surface 242 of the inner cylinder 240 and the base end surface 252 of the outer cylinder 250 come into close contact with the shoulder 140, thereby further improving the sealing performance of the seal mechanism 300.

[0085] When the brush-side neck portion 220 includes an inner tubular portion 240 and an outer tubular portion 250, the sealing performance of the sealing mechanism 300 can be improved by configuring either the base end surface 242 of the inner tubular portion 240 or the base end surface 252 of the outer tubular portion 250 to abut against the shoulder portion 140. Therefore, the base end surfaces 242, 252 of the inner tubular portion 240 and the outer tubular portion 250 do not have to be configured to abut against the shoulder portion 140 as shown in this embodiment, and for example, only one of the base end surfaces may be configured to abut against the shoulder portion 140.

[0086] Next, the procedure for separating the brush-side neck portion 220 and the handle-side neck portion 120 will be described with reference to FIGS.

[0087] The fitting portion 310 is configured to be able to release the fitting between the connecting portion 230 and the mouth portion 130 and the shoulder portion 140 in response to a pressing operation that presses the connecting portion 230 of the brush-side neck portion 220 from the outer peripheral surface side. Specifically, as shown in FIG. 4 , a user can bend the outer cylindrical portion 250 toward the gap g by pinching the outer peripheral surface of the outer cylindrical portion 250 that constitutes the connecting portion 230 with fingers or the like and applying force F. When the outer cylindrical portion 250 is bent toward the gap g, the inner peripheral surface of the outer cylindrical portion 250 comes into contact with the inner cylindrical portion 240. When the outer cylindrical portion 250 is pressed against the outer peripheral side of the inner cylindrical portion 240, the second protrusion 235 is released from the engagement with the first recess 135.

[0088] As shown in Figure 5, the user can easily disconnect the handle portion 100 and the brush portion 200 by moving the handle portion 100 and the brush portion 200 relatively apart toward the tip end and base end when the second protrusion portion 235 is no longer caught in the first recess portion 135.

[0089] As described above, the toothbrush 10 according to this embodiment has a structure in which the handle portion 100 and the head portion 210 can be connected and separated, thereby improving material recyclability and enabling the provision of a wide variety of toothbrushes. Furthermore, when the handle portion 100 and the head portion 210 are connected, the internal space 113 of the handle body 110 can be maintained airtight, thereby increasing the strength of the handle body 110. This prevents the handle body 110 from accidentally deforming while a user is holding the handle body 110 and brushing their teeth. This reduces the deterioration in usability that would otherwise occur due to deformation of the handle body 110 during toothbrushing. Furthermore, because the strength of the handle body 110 can be increased, the toothbrush 10 can further reduce the thickness of the handle body 110. This further improves material recyclability.

[0090] Next, modified examples of the toothbrush according to the present invention will be described. In the description of each modified example, redundant explanations of the components and contents already explained in the above embodiment will be omitted.

[0091] <Variation 1> FIG. 6 shows a partial cross-sectional view of a toothbrush according to the first modification.

[0092] In the first modification, the fitting portion 310 is configured so that the fitting between the mouth portion 130 and the shoulder portion 140 and the insertion portion 231 can be released in accordance with a rotation operation that rotates the brush portion 200 and the handle portion 100 relative to each other.

[0093] As shown in Fig. 6, the inner and outer cylindrical portions 240 and 250 constituting the connecting portion 230 are configured so that their lengths along the longitudinal direction differ in a portion of the circumference relative to the central axis c1. In the example shown in Fig. 6, the inner and outer cylindrical portions 240 and 250 are formed so that the lower portions in the figure are longer than the upper portions. Furthermore, the shoulder portion 140 is formed in a cross-sectional shape such that a portion of the circumference forms an upright wall surface in accordance with the difference in the partial lengths of the inner and outer cylindrical portions 240 and 250.

[0094] When the user rotates the inner and outer cylinders 240 and 250 as shown by the arrow r in the figure, the longer portions of the inner and outer cylinders 240 and 250 can be brought into contact with the upright portion of the shoulder 140. This allows the user to release the engagement of the engaging portion 310, and the handle 100 and the brush 200 can be easily separated.

[0095] <Variation 2> 7 and 8 show partial cross-sectional views of a toothbrush according to the second modification.

[0096] In the toothbrushes according to Modifications 2 and 3, mouth portion 130 has a predetermined thick portion 138. Thick portion 138 is located closer to the base end than the tip of mouth portion 130, and is formed to be thicker than the tip of mouth portion 130. Toothbrushes with thick portion 138 have the following advantages.

[0097] When the handle portion 100 is manufactured by blow molding, forming the thick portion 138 allows the handle body 110 to be uniformly stretched and expanded along the longitudinal direction during blow molding, thereby preventing the handle body 110 from having locally reduced strength.

[0098] Thick portion 138 can be configured, for example, as a neck ring type (a ring shape with an increased outer diameter at a portion of mouth portion 130) as shown in Fig. 7, or as a neck shoulder type (a shape with an increased thickness partially extending from the base end side of mouth portion 130 toward shoulder portion 140) as shown in Fig. 8. When thick portion 138 is configured as a neck ring type, thick portion 138 can be hooked and transported during the toothbrush manufacturing process, thereby improving productivity.

[0099] The thickness ratio (t3 / t1) of the thickness t3 of the thick portion 138 to the thickness t1 of the mouth portion 130 (see FIG. 1) is, for example, preferably 1.2 to 3, and more preferably 1.5 to 2.5.

[0100] <Variation 3> 9 to 11 show a third modified example of the shape of the handle body 110. FIG.

[0101] The cross-sectional shape of the handle body 110 does not have to be a cylindrical shape that is formed substantially uniformly along the longitudinal direction as shown in FIG. 1. For example, from the viewpoint of improving strength, it can be formed into a barrel shape in which the cross-sectional area at the base end is larger than that at the tip end as shown in FIG. 9. Other than that, for example, the cross-section perpendicular to the central axis c1 may be formed into a polygonal shape, or a shape with a constricted shape in which the cross-sectional area periodically increases and decreases. Also, while palm grips and pen grips are well-known ways of holding toothbrushes, when holding the toothbrush in these ways, it is also possible to provide the toothbrush with recesses or indentations where the thumb, index finger, middle finger, etc. can be placed to enable the user to hold the toothbrush firmly.

[0102] Furthermore, by providing ribs (horizontal ribs) extending in the circumferential direction shown in FIG. 10 and / or ribs (vertical ribs) extending in the longitudinal direction shown in FIG. 11, the strength of the handle body 110 can be improved.

[0103] <Variation 4> 12 to 14 show a fourth modification relating to a device for improving the sealing performance of the sealing mechanism 300 (fitting portion 310).

[0104] 12, the toothbrush may have a seal member 410 disposed between the distal end surface 132 of the mouth portion 130 and the distal end surface 232 of the connecting portion 230. By disposing the seal member 410 in the toothbrush, the tightness between the distal end surface 132 of the mouth portion 130 and the distal end surface 232 of the connecting portion 230 can be improved. This further improves the airtightness of the internal space 113 of the handle body 110. The seal member 410 can be formed, for example, from a known O-ring made of elastomer or the like, or a ring or sheet made of low-hardness PE or PP.

[0105] 13, the toothbrush may have a valve structure 420 on the distal end surface 232 of the connecting portion 230 to improve airtightness between the distal end surface 132 of the mouth portion 130 and the distal end surface 232 of the connecting portion 230. The valve structure 420 may be formed, for example, by a cusp valve portion in which a portion of the distal end surface 232 of the connecting portion 230 protrudes toward the central axis c1. By providing the valve structure 420, the toothbrush can improve adhesion between the distal end surface 132 of the mouth portion 130 and the distal end surface 232 of the connecting portion 230. This can further improve the airtightness of the internal space 113 of the handle body 110.

[0106] 14, the toothbrush may have an adhesive 430 disposed between the outer circumferential surface of the mouth portion 130 and the inner circumferential surface of the inner tube portion 240. The adhesive 430 is preferably, for example, a water-insoluble, water-repellent grease with an appropriately adjusted viscosity. By providing the adhesive 430, the toothbrush can improve the adhesion between the outer circumferential surface of the mouth portion 130 and the inner circumferential surface of the inner tube portion 240. This can further improve the airtightness of the internal space 113 of the handle body 110.

[0107] The structures described in the above-mentioned modifications can be selectively and arbitrarily combined with the toothbrush of the present invention, as long as the effects of each modification are not impaired.

[0108] The toothbrush according to the present invention has been described above through embodiments and modifications, but the present invention is not limited to the contents described in the specification and can be modified as appropriate based on the claims.

[0109] For example, the toothbrush described in the embodiment has been illustrated as having a structure in which the brush neck portion covers a portion of the handle neck portion when the handle portion and the brush portion are connected, but this structure is not limited to this. The toothbrush may have a structure in which the handle neck portion covers a portion of the brush neck portion when the handle portion and the brush portion are connected. In other words, the toothbrush may have a structure in which a portion of the brush neck portion is inserted into the handle neck portion. [Explanation of symbols]

[0110] 10 Toothbrush 100 Handle 110 Handle body 113 Interior Space 120 Handle side neck 130 Mouth 131 Tip opening 132 Tip of the mouth 133 Hollow part 135 First recess 138 Thick part 140 Shoulder 200 Brush section 210 Head 211 Hair Bundle 220 Brush side neck 230 Connection 231 Insertion part 232 Tip surface of connection part 235 Second convex part 240 Inner cylinder 242 Base end surface of inner cylinder 250 outer cylinder 252 Base end surface of outer cylinder 300 Sealing mechanism 310 Fitting part 410 Sealing material 420 Valve Structure 430 Adhesion material, D1 Outer diameter of handle body D2 Outer diameter of mouth c1 Central shaft of toothbrush g Gap t1 Handle body thickness t2 Thickness of the mouth t3 Thickness of thick part ta: inner cylinder wall thickness tb Outer cylinder wall thickness tc gap distance

Claims

1. a handle portion including a handle body having a hollow internal space formed therein and configured to be grippable, and a handle-side neck portion disposed on the distal end side of the handle body in the longitudinal direction and having a hollow opening formed therein that communicates with the internal space; a brush part including a head part in which tufts of bristles are implanted, and a brush-side neck part extending from the head part toward the base end in the longitudinal direction and having a connecting part formed therein that can be connected to and separated from the mouth part; a sealing mechanism that maintains the airtightness of the internal space when the opening and the connection portion are connected, the brush-side neck portion has a closed structure in which no space communicating between the inside and outside of the head portion is formed, The outer diameter of the mouth portion is smaller than the outer diameter of the handle body, the handle-side neck portion is formed on the base end side of the mouth portion in the longitudinal direction, and has a shoulder portion whose outer diameter gradually increases from the mouth portion side toward the handle body side, the connecting portion has an insertion portion into which the mouth portion and the shoulder portion can be inserted, The sealing mechanism is composed of a fitting portion that maintains the airtightness of the internal space by fitting the brush side neck portion and the handle side neck portion together as the mouth portion and the shoulder portion are inserted into the insertion portion.

2. The toothbrush according to claim 1 , wherein the tip surface of the mouth portion abuts against the tip surface of the connecting portion located at the tip side of the insertion portion when the mouth portion and the shoulder portion are inserted into the insertion portion.

3. a first recess recessed radially inward of the mouth portion and / or a first protrusion protruding radially outward of the mouth portion is formed on an outer peripheral surface of the mouth portion, A toothbrush as described in claim 1 or claim 2, wherein the connection portion is formed with a second convex portion that abuts against the outer surface of the first concave portion and / or a second concave portion that abuts against the outer surface of the first convex portion when the mouth portion and the shoulder portion are inserted into the insertion portion.

4. The toothbrush according to any one of claims 1 to 3, wherein the ratio (D1 / D2) of the outer diameter (D1) of the handle body to the outer diameter (D2) of the opening is 1.2 or more and 10 or less.

5. The toothbrush according to any one of claims 1 to 4, wherein the length ratio (L1 / L2) of the length (L1) of the handle body along the longitudinal direction to the length (L2) of the mouth portion along the longitudinal direction is 2.5 or more and 30 or less.

6. The toothbrush according to any one of claims 1 to 5, wherein the fitting portion is configured to be able to release the fitting in response to a pressing operation that presses the connection portion from the outer surface side, or a rotation operation that rotates the brush portion and the handle portion relative to each other.

7. the connecting portion has an inner cylindrical portion and an outer cylindrical portion arranged to cover the inner cylindrical portion with a gap between them, The toothbrush according to any one of claims 1 to 6, wherein the base end surface of the inner tube portion and / or the base end surface of the outer tube portion abuts against the shoulder portion when the mouth portion and the shoulder portion are inserted into the insertion portion.

8. The toothbrush according to any one of claims 1 to 7, wherein the mouth portion has a thick portion that is located closer to the base end than the tip of the mouth portion and is formed to be thicker than the tip of the mouth portion.

Images