JP2023084285A - toothbrush - Google Patents

Abstract

To provide a toothbrush that can demonstrate a high impact relaxation effect, can maintain excellent operability and cleanability in normal use, can be molded easily, and can be efficiently manufactured.SOLUTION: There is provided a toothbrush in which a handle part 4 includes a core material part 5 made of a first rigid resin integrally formed with a neck part 3 and a coating body 6 formed so as to coat the core material part 5 with a second rigid resin having low adhesion properties low in weldability to the first rigid resin, an external surface of the coating body 6 functioning as a grip part. The core material part 5 and the coating body 6 are provided with an engaging protrusion part 7a and an engaged part 7b which engage with each other for inhibiting the core material part 5 from relatively moving to a base end side of the coating body 6. When force exceeding predetermined force is applied, the engagement state between the engaging protrusion part 7a and the engaged part 7b is released when the engaging protrusion part and the engaged part are separated from each other or the engaging protrusion part is broken, thereby permitting the relative movement.SELECTED DRAWING: Figure 2

Description

The present invention consists of a head portion in which hair bundles are implanted, a neck portion connected to the base end side of the head portion, and a handle portion connected to the base end side of the neck portion and serving as a handle. In particular, it relates to a toothbrush that can reduce the impact when the throat is poked.

As a toothbrush of this kind, conventionally, a toothbrush for infants has been proposed in which a cushioning portion made of a thermoplastic elastomer is provided on the proximal end of the handle to reduce the impact when the throat is poked (for example, patent Reference 1).

However, conventional ones absorb the impact by bending the elastomer material. The cleanability is remarkably lowered, and it is difficult to achieve both, and the material is expensive, and molding is difficult.

Japanese Unexamined Patent Application Publication No. 2018-202004

Therefore, in view of the above-mentioned situation, the present invention aims to solve a toothbrush that has a high shock mitigation effect, can maintain good operability and cleanability during normal use, is easy to mold, and can be manufactured efficiently. in that it provides

The present invention includes the following inventions.
(1) A head portion having a bundle of hair implanted therein, a neck portion connected to the base end of the head portion, and a handle portion connected to the base end of the neck portion to serve as a handle. In addition, the handle portion is formed by a core portion made of a first hard resin integrally formed with the neck portion, and a second hard resin having a property of low adhesion to the first hard resin. and a cover formed to cover a core portion, wherein the outer surface of the cover functions as a grip portion, wherein the core portion and the cover are engaged with each other. An engaging projection or an engaged portion is provided for inhibiting the core portion from moving relative to the base end of the cover, and the engaging projection and the engaged portion exceed a predetermined force. A toothbrush configured to disengage from the engaged state by separating from each other or by breaking the engaging projections when a force is applied, thereby allowing the relative movement.

(2) The toothbrush according to (1), wherein at least a partial region of the boundary surface between the core portion and the cover is an inclined surface whose peripheral length increases toward the base end side.

(3) The toothbrush according to (2), wherein the inclined surface is a tapered surface with an inclination angle of 5° or less.
(4) The toothbrush according to any one of (1) to (3), which is manufactured using a mold with a top-and-bottom split structure.

In the toothbrush according to the present invention as described above, the engaging projection and the engaged portion are separated from each other or the engaging projection is broken when a force exceeding a predetermined force acts, so that the engaged state is broken. Since it is constructed so as to allow disengagement and relative movement, it is highly effective in alleviating impact, and it is easy to maintain good operability and cleanability during normal use.

In other words, instead of deforming an elastomer material to absorb the impact as in the conventional art, the engaging protrusion and the engaged portion are disengaged from each other to form the core portion and the gripping portion. are moved relative to each other in the axial direction to alleviate the impact, it is easy to set the force when the engagement is released by the structural design of the engaging projection and the engaged portion to a predetermined value as intended. Therefore, it is possible to easily achieve both the impact mitigation effect and the operability and cleanability during normal use.

In addition, there is no need to use a specific expensive elastomer, and the material selection is relatively wide, so costs can be reduced.In addition, it can be manufactured easily and efficiently by two-color molding instead of assembling multiple parts. .

Further, when at least a partial region of the boundary surface between the core portion and the cover is an inclined surface whose peripheral length increases toward the base end side, the engagement protrusion and the engaged portion are separated from each other. It is possible to avoid a situation in which a gap is formed between the core member and the cover as soon as the concave-convex engagement is disengaged, and the movement of the relative movement is deteriorated due to friction. Also, even if it is thrust obliquely with respect to the axial direction, the engagement state is disengaged and the impact can be reduced. Furthermore, since reverse movement is prevented by such an inclined surface, even in a structure in which the core portion side protrudes toward the base end side of the cover, the core portion side may fall and be pushed by the floor or wall. When it tries to move to the tip side, the movement is blocked, and throat thrust can be prevented more reliably.

When the inclined surface is a tapered surface with an inclination angle of 5° or less, the inclination or outer diameter of the gripping portion does not become too large, and good gripping ability can be maintained.
In addition, when the mold is manufactured with a mold having a top-and-bottom split structure, the molded product can be taken out by opening only in one direction, so manufacturing can be performed efficiently.

1 is a perspective view showing a toothbrush according to a representative embodiment of the present invention; FIG. A longitudinal sectional view of the same toothbrush. Similarly, the disassembled perspective view of a toothbrush. (a) and (b) are explanatory diagrams showing the operation of the toothbrush for similarly mitigating the impact. Explanatory drawing which similarly shows a mode that the toothbrush is mitigating the impact. Explanatory drawing which shows the modification of an engaging protrusion and a to-be-engaged part. FIG. 11 is an explanatory diagram showing another modified example of the engaging protrusion and the engaged portion; FIG. 11 is an explanatory diagram showing still another modified example of the engaging projection and the engaged portion. (a) (b) is explanatory drawing which shows the modification of the toothbrush of this invention. Explanatory drawing which similarly shows the operation|movement which relieve|moderates the impact of the toothbrush of a modification. (a) and (b) are explanatory views showing other modifications of the toothbrush of the present invention. Explanatory drawing which similarly shows the operation|movement which relieve|moderates the impact of the toothbrush of another modification. (a) and (b) are explanatory views showing still another modification of the toothbrush of the present invention.

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, the toothbrush 1 of the present invention includes a head portion 2 having tufts of bristles 20 implanted thereon, and a substantially rod-shaped head portion 2 connected to the base end side (rear end portion) of the head portion 2 . and a handle 4 that is connected to the proximal end (rear end) of the neck and serves as a handle. The handle portion 4 includes a core portion 5 formed integrally with the neck portion 3 from a first hard resin such as polyacetal resin (POM), and a hard core portion 5 having a property of low adhesion to the first hard resin. A cover 6 formed so as to cover the core portion 5 with a resin, that is, a second hard resin that does not mix with the first hard resin during molding and has the property of being separated from each other after molding. and the outer surface of the cover 6 functions as a grip

For example, a crystallized resin made of polyacetal resin (POM), polyamide resin (PA), polybutylene terephthalate (PBT), polypropylene resin (PP), etc., when the other party is a crystallized resin (except for PP) , or in the case of non-crystallizing resins, have the property of low adhesion to each other.

For this reason, one of the first hard resin constituting the core part 5 and the second hard resin constituting the covering 6 is a crystallized resin such as polyacetal resin (POM), and the other is, for example, By using an amorphous resin such as acrylonitrile-butadiene-styrene resin (ABS), polycarbonate (PC) or acrylic resin (PMMA), the first hard resin and the second hard resin can be mixed during molding. Instead, the core part 5 and the cover 6 can be separated from each other after molding.

In addition, among the crystallized resins, polypropylene resin (PP) has high adhesion to each other. Even when both the first hard resin and the second hard resin are crystallized resins, it is possible to prevent the core member 5 and the cover 6 from being fused together.

For this reason, for example, one of the first hard resin constituting the core part 5 and the second hard resin constituting the covering 6 is a crystallized resin such as polyacetal resin (POM), and the other is , polyacetal resin (POM), polyamide resin (PA), polybutylene terephthalate (PBT), polypropylene resin (PP), or the like. and the second cured resin can be prevented from being mixed with each other, and the core member 5 and the cover 6 can be separated from each other after molding.

As shown in FIGS. 1 to 3, the core part 5 and the cover 6 have engaging protrusions that engage with each other to prevent the core part 5 from moving relative to the base end of the cover 6. 7a or the engaged portion 7b is provided. In this embodiment, as the engaged portion 7b, a notch groove 50 opened toward the proximal end is symmetrical about the axis in the outer peripheral portion of the proximal end of the core portion 5 (the outer peripheral portion of the rear end). The notch grooves 50 are formed at two positions corresponding to the notch grooves 50 on the inner circumference of the proximal end (inner circumference of the rear end) of the cover 6 as the engaging protrusions 7a. A protruding piece 61 is formed in a state of being engaged with projections and recesses (fitting into projections and recesses).

When a force exceeding a predetermined force (for example, 2 kgf, which can be set to an appropriate size) acts, such as when the user puts the toothbrush too far into the back of the mouth and pokes the throat, the force shown in FIGS. , the protruding piece 61 (engaging protruding portion 7a) of the core portion 5 is broken, the engagement state with the notch groove 50 (engaged portion 7b) is released, and the main body including the core portion 5 The side is designed to move relatively to the base end side of the gripped cover 6 to mitigate the impact force. A reference numeral 610 indicates a broken piece formed by breaking and breaking the projecting piece 61 .

In this embodiment, as shown in FIGS. 1 to 3, at least a partial region of the boundary surface 40 between the core member 5 and the cover 6 is an inclined surface whose peripheral length increases toward the base end side. As a result, the cover 6 is prevented from slipping out toward the base end during normal toothbrushing. In this example, the entire area of the boundary surface 40 is composed of a tapered surface that is inclined at a substantially constant angle. That is, the outer peripheral surface of the core portion 5 and the inner peripheral surface of the cover 6 are tapered.

Providing an inclined surface on the boundary surface 40 in this way has other effects. That is, with such an inclined surface, as shown in FIG. A gap 41 is formed between the member 5 and the cover 6 . Therefore, it is possible to prevent the friction between the core member 5 and the covering body 6 even after the concave-convex engagement is released, resulting in poor movement and reduced shock absorbing effect.

Further, even if the projection is made obliquely to the axis, if the tapered surface is formed as in this example, a force acts on at least one of the engaging projections 7a in a direction perpendicular to the projecting direction. As expected, it becomes easy to break, and when one breaks, force acts on the others, making them easier to break. However, if the inclination angle of the inclined surface becomes too large, the inclination or the outer diameter of the gripping portion becomes large, and the gripping property deteriorates.

The engaging projection 7a and the engaged portion 7b may be a combination other than the combination of the projecting piece 61 on the covering body 6 side and the notch groove 50 on the core member 5 side described above. In this example, the projecting piece 61 and the notch groove 50 are formed at the edges of the base end (rear end) of the cover 6 and the core member 5, respectively. A protrusion 61 and a concave portion may be provided at the inserted position. However, in this case, the broken protruding piece 61 may get caught between the cover 6 and the core part 5, and may become a resistance between the two. formed in the part.

Alternatively, as shown in FIG. 6, a protrusion 51 may be provided on the core member 5 side as the engaging protrusion 7a, and a concave portion 60 may be provided on the cover 6 side as the engaged portion 7b. A reference numeral 510 indicates a broken piece formed by breaking and breaking the projecting piece 51 . As shown in FIG. 7, the engaged portion 7b for the protruding piece 61 on the side of the cover 6 engages with the outer peripheral edge portion 52 of the base end surface (rear end surface) of the core portion 5 as shown in FIG. It can also be a structure that fits. However, in this case, the core part 5 and the covering body 6 are engaged in the circumferential direction while allowing relative movement in the axial direction so that the core part 5 and the covering body 6 do not rotate relative to each other in the circumferential direction about the axis. It is preferable to separately form a concave-convex engaging structure.

The engaging projection 7a and the engaged portion 7b exemplified above show an example in which the engagement projection 7a is broken and the uneven engagement is released. A structure in which the concave-convex engagement is released by separating them from each other may be employed. For example, in FIG. 8(a), a projecting piece 61 formed on the cover 6 as the engaging projection 7a is formed between a pair of through grooves 62 along the axial direction opened to the base end surface of the cover 6. It has an L-shaped structure.

According to such a structure, when a force exceeding a predetermined force acts, such as when the throat is poked, as shown in FIG. and is separated from the notch groove 50 (engaged portion 7b) of the core member 5, the engaged state is released, and the main body side including the core member 5 is held by the user's hand. It can relatively move to the base end side of the cover 6 to reduce the impact force.

Also, as shown in FIG. 8(b), one or a plurality of through grooves 63 along the axial direction, which are similarly opened in the base end face of the cover 6, are provided at positions different from the protruding pieces 61 to form a throat. When a force exceeding a predetermined force such as a thrust is applied, the entire base end portion of the cover 6 including the projecting piece 61 is deformed so as to swell outward, and similarly the projecting piece 61 (engagement projection 7a) is engaged with the core. It is separated from the notch groove 50 (engaged portion 7b) of the material portion 5, the engaged state is released, and the body side including the core portion 5 faces the base end side of the cover 6 gripped by hand. It can also be configured to move and absorb the impact force.

In the above example, the base end surface (rear end surface) of the core member 5 and the base end surface (rear end surface) of the cover 6 are substantially flush with each other, but the present invention is not limited to this. For example, as shown in FIG. 9, the base end of the core member 5 may be configured to project from the base end of the cover 6 in a normal state. In this case also, as in the above example, when a force exceeding a predetermined force acts, such as when the throat is poked, the protrusion 61 (engagement protrusion 7a) is broken as shown in FIG. The engaged state with the engaged portion 7b) is released, and the main body side including the core portion 5 relatively moves toward the base end side of the cover 6 gripped by the hand, so that the impact force can be alleviated. ing.

Also in this example, the inclined surface (tapered surface) is formed on the boundary surface to prevent reverse movement. Therefore, in the case of the structure in which the core part 5 side protrudes toward the base end side of the cover 6 as in this example, when the user falls, the base end part of the core part 5 is pushed by the floor or wall, Even when it tries to move to the right, the movement is blocked and the throat can be prevented.

In addition, in the structure in which the core part 5 protrudes toward the base end side of the cover 6 as in this example, the outer diameter of the cover 6 may become small, making it difficult to grip. As shown in 12, the thickness and shape of the outer peripheral surface of the cover 6 can be freely set, so that the thickness and shape can be appropriately set so as to be easily gripped without being affected by the slope of the boundary surface.

Further, as shown in FIG. 13, it is preferable to further include a narrow diameter portion 53 at the tip of the handle portion 4 so that the neck portion 3 can be relatively swung and displaced in a direction orthogonal to the axial direction. As a result, when the throat is poked, the head part 2 swings together with the neck part 3, and the impact can be further reduced. Since it is a structurally movable mechanism, it has a high degree of freedom in design without deteriorating cleanability and operability.

In this example, the tip portion of the core portion is configured to be bent and deformable as a small diameter portion 53 having a relatively smaller cross-sectional area than the front and rear, and the neck portion 3 at the tip portion of the corresponding cover 6 is swung. A through groove 64 opened at the tip side is provided to allow bending in the direction of the outer diameter without interfering with the bent small diameter portion. In this example, through grooves 64 are provided in the projecting direction (abdominal side) and the back side (dorsal side) of the hair bundles 20 of the head portion 2 so that the neck portion 3 can swing in these two directions.

A gap s1 is formed between the small-diameter portion 53 and the portion of the cover 6 other than the through groove 64. Since the through groove 64 exists in such a gap s1, upper and lower splitting is performed during two-color molding. It can be formed without problems with the secondary mold of the structure. Although the small-diameter portion 53 has a straight columnar shape, it is not limited to this, and various structures are possible.

Next, the manufacturing procedure of the toothbrush of the representative embodiment shown in FIGS. 1 to 3 will be described.

First, the primary mold for molding the primary molded product 11 (see FIG. 3) in which the toothbrush head portion 2, the neck portion 3, and the core portion 5 of the handle portion 4 are integrally connected was clamped. In this state, a first hard resin made of a crystallized resin such as polyacetal resin (POM) is injected into the primary mold to mold the primary molded product 11 . For the primary mold, a mold with an efficient upper and lower split structure can be adopted.

Next, after the primary mold is opened, the secondary mold for molding the secondary molded product 12 composed of the covering 6 is clamped, and the first hard material is placed in the secondary mold. Cured resins with properties of low adhesion to resins, such as acrylonitrile-butadiene-styrene resins (ABS), polycarbonate (PC), acrylic resins (PMMA), and other amorphous resins, or polyacetal resins (POM), polyamides A secondary molded product 12 is molded by injecting a second hard resin made of a crystallized resin such as resin (PA), polybutylene terephthalate (PBT), or polypropylene resin (PP). As for the secondary mold, it is possible to adopt a mold with an efficient upper and lower split structure.

In this manner, a toothbrush in which the core part 5 of the primary molded product 11 made of the first hard resin is covered with the coating 6 made of the second hard resin can be molded. A transparent material may be used as the second cured resin forming the coating 6 . The term "transparent" means that visible light can be permeated. Also, even a resin mixed with a small amount of a substance that does not transmit visible light (for example, lame, pigment, etc.) is considered transparent if it can transmit visible light.

As the transparent synthetic resin, it is particularly preferable to use a resin having a value of 80% or more as measured by the test method of JIS K 7105. If the cover 6 is made of the second cured resin made of a transparent material in this way, the pattern provided on the outer peripheral surface of the core part 5 can be seen through the cover 6, thereby designing the toothbrush. can improve sexuality.

In this manner, the head portion 2 having the hair bundles 20 implanted therein, the neck portion 3 connected to the head portion 2, and the handle portion 4 serving as a handle are formed integrally with the neck portion 3. a toothbrush in which a handle portion 4 is constituted by a core portion 5 made of a first hard resin and a cover 6 made of a second hard resin having a property of low adhesion to the first hard resin. , can be manufactured easily and inexpensively by two-color molding. Since the core part 5 of the primary molded product 11 and the cover 6 of the secondary molded product 12, which constitute the handle 4 of the toothbrush, are formed of a hard resin having a property of low adhesion to each other, the primary molded product Although the toothbrush in which 11 and the secondary molded product 12 are combined is formed by two-color molding, the core part 5 and the cover 6 are prevented from being fused together.

A user of the toothbrush can brush his teeth by bringing the bristle tufts 20 of the head portion 2 into contact with his teeth while stably gripping the cover 6 located on the outer peripheral portion of the handle portion 4 . In addition, it is possible to manufacture toothbrushes at low cost by selecting two types of hard resins that are less expensive than elastomers, instead of using soft resins such as elastomers that are expensive as in the past.

In addition, instead of the above-described embodiment in which the toothbrush composed of the primary side molded product 11 and the secondary side molded product 12 is formed by two-color molding, the head portion 2 and the neck portion 3 of the toothbrush are formed by the first cured resin. A molded product in which the core part 5 is integrally connected and a molded product in which the cover body 6 is formed of the second cured resin are separately formed by means of injection molding or the like, and then these are assembled. Integral coupling is also possible depending on the concave-convex engaging structure. However, in this case, the manufacturing process is complicated and the manufacturing cost is inevitably high. It is preferable to manufacture at low cost.

Although the embodiments of the present invention have been described above, the present invention is by no means limited to such embodiments, and can of course be embodied in various forms without departing from the gist of the present invention.

1 Toothbrush 2 Head Part 3 Neck Part 4 Handle Part 5 Core Material Part 6 Cover 7a Engaging Projection 7b Engaged Part 11 Primary Side Molded Product 12 Secondary Side Molded Product 20 Hair Bundle 40 Boundary Surface 41 Gap 50 Notch Groove 51 Protruding piece 52 Peripheral edge 53 Small diameter portion 60 Recess 61 Protruding piece 62 Through groove 63 Through groove 64 Through groove 510, 610 Broken piece s1 Gap

Claims (4)

a head section in which hair bundles are implanted;
a neck portion connected to the base end side of the head portion;
and a handle that is connected to the proximal end of the neck and serves as a handle,
The handle is
a core part made of a first hard resin integrally formed with the neck part;
a cover formed so as to cover the core portion with a second hard resin having a property of low adhesion to the first hard resin;
A toothbrush in which the outer surface of the covering functions as a grip,
The core part and the cover are provided with an engaging protrusion or engaged part that engages with each other to prevent the core part from moving relative to the base end of the cover,
When a force exceeding a predetermined force acts on the engaging protrusion and the engaged portion, the engaged state is released by separating from each other or the engaging protrusion is broken, thereby allowing the relative movement. A toothbrush characterized by comprising: 2. The toothbrush according to claim 1, wherein at least a part of the boundary surface between said core portion and said cover is an inclined surface whose peripheral length increases toward the base end side. 3. The toothbrush according to claim 2, wherein said inclined surface is a tapered surface with an inclination angle of 5[deg.] or less. The toothbrush according to any one of claims 1 to 3, which is manufactured with a mold having a top and bottom split structure.

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