JP7515394B2 - Replaceable toothbrush - Google Patents

Description

The present invention relates to a replaceable toothbrush.

In recent years, as environmental problems have become more serious, there has been a demand to reduce the amount of resin waste, and in the field of toothbrushes, replaceable toothbrushes in which the head is replaced have been proposed.
For example, a replaceable toothbrush is known in which a replacement brush can be detachably attached to the tip side of the brush body by inserting a shaft portion extending in the longitudinal direction from the tip of the brush body into a hole formed at the rear end of the replacement brush (Patent Document 1).

JP 2013-17670 A

However, with the replaceable toothbrushes, when trying to remove the replacement brush, the hand may slip along the longitudinal axis of the toothbrush and accidentally touch the head, which can be perceived as unhygienic by users.

A possible mechanism for preventing hands from slipping in the long axis direction when attaching or detaching a replacement brush is to form a groove-shaped shaft insertion part on the outer periphery of the replacement brush that extends in the long axis direction and reaches the rear end, and insert the shaft part extending from the tip of the brush body into the shaft insertion part from an opening on the outer periphery side of the replacement brush. With such a mechanism, the shaft part is moved in the short axis direction when replacing the replacement brush, so that hands are less likely to slip in the long axis direction and hands are prevented from accidentally touching the head part.
However, in replaceable toothbrushes that use this mechanism, the long, grooved shaft insertion section is noticeable even when the replacement brush is attached, and the shaft inside the shaft insertion section is visible from the opening on the outer surface of the replacement brush, which may make the user feel that the toothbrush is unhygienic.

The present invention aims to provide a replaceable toothbrush that is hygienic and prevents the hand from slipping along the longitudinal axis when replacing the replacement brush, and makes the shaft and shaft insertion part less noticeable when the replacement brush is attached.

The present invention has the following aspects.
[1] A replaceable toothbrush comprising a brush body and a replacement brush removably attached to a tip side of the brush body,
The brush body includes a handle portion and a shaft portion extending in a longitudinal direction from a tip of the handle portion,
The replacement brush includes an attachment portion attached to a tip side of the brush body,
The mounting portion is formed with a groove-shaped shaft insertion portion that opens on an outer circumferential surface and a rear end surface of the mounting portion and extends in a longitudinal direction,
The shaft portion is inserted into the shaft insertion portion from an opening on the outer circumferential surface side of the attachment portion, whereby the replacement brush is attached to the brush body portion,
A replaceable toothbrush, wherein when the replacement brush is attached to the brush body, at least a portion of the shaft within the shaft insertion portion is shielded by a shielding portion when viewed from the opening on the outer circumferential surface side of the attachment portion.
[2] The shielding portion extends in the longitudinal direction from the tip of the handle portion and is disposed closer to the outer circumferential surface of the handle portion than the shaft portion,
The replaceable toothbrush of [1], wherein both the shielding portion and the shaft portion are inserted into the shaft insertion portion, and the shaft portion is shielded by the shielding portion when viewed from the opening on the outer peripheral surface side of the attachment portion.
[3] The shielding portion and the shaft portion are connected to form a connecting body,
The replaceable toothbrush according to [2], wherein the replacement brush is attached to the brush body by inserting the connecting body into the shaft insertion portion from an opening on the outer peripheral surface side of the attachment portion.
[4] A recess is formed between the shielding portion and the shaft portion on at least one of the tip side and the side surface side of the connector,
a leaf spring portion into which the shaft portion inserted into the shaft insertion portion is fitted is provided inside the mounting portion,
The replaceable toothbrush according to [3], wherein the shaft portion of the connector inserted into the shaft insertion portion, where the recessed portion is formed, is fitted into the leaf spring portion.
[5] A replaceable toothbrush as described in [4], in which the recess is formed between the shielding portion on the tip side of the connecting body and the shaft portion, and the tip portion of the shaft portion is fitted into the leaf spring portion.
[6] A leaf spring portion into which the shaft portion inserted into the shaft insertion portion is fitted is provided inside the mounting portion,
The leaf spring portion includes a pair of spring pieces surrounding the shaft portion from both sides when viewed in the longitudinal direction,
The replaceable toothbrush according to [1], wherein, when viewed from the opening on the outer circumferential surface side of the attachment portion, the pair of spring pieces act as the shielding portion and shield at least a portion of the shaft portion.
[7] The pair of spring pieces each have a facing surface that is parallel to a radial direction from an opening on an outer peripheral surface side of the mounting portion toward a central axis and faces each other,
The replaceable toothbrush according to [6], wherein the length of the opposing surface is greater than the length of the shaft portion in the radial direction.
[8] A replaceable toothbrush as described in [6], wherein, when viewed in the longitudinal direction, at least one of the pair of spring pieces has an inclined surface that approaches the other spring piece as it moves from the tip to the base end.

The present invention provides a hygienic replaceable toothbrush that prevents the hand from slipping along the longitudinal axis when replacing the replacement brush, and makes the shaft and shaft insertion part less noticeable when the replacement brush is attached.

FIG. 1 is a front view of a replaceable toothbrush according to a first embodiment. FIG. 2 is a side view of the replaceable toothbrush of FIG. 1 . 3A, 3B, and 3C are diagrams showing a replacement brush for the replaceable toothbrush of FIG. 1, in which FIG. 3A is a front view, FIG. 3B is a side view, and FIG. 3C is a bottom view. FIG. 2 is an enlarged perspective view of a shaft portion of the brush body of the replaceable toothbrush of FIG. 1 . 2 is a front view showing a state in which a replacement brush is attached to a brush body in the replaceable toothbrush of FIG. 1. [0023] FIG. 2 is a cross-sectional view of the replaceable toothbrush of FIG. 1 along the line AA. FIG. 11 is a cross-sectional view of a mounting portion of a replaceable toothbrush according to another embodiment. FIG. 11 is an enlarged perspective view of a shaft portion of a brush body of a replaceable toothbrush according to another embodiment. 9 is a cross-sectional view of the mounting portion of the brush body of FIG. 8 in a state where a replacement brush is mounted. FIG. 11 is an enlarged perspective view of a shaft portion of a brush body of a replaceable toothbrush according to another embodiment. FIG. 11 is a front view of a replaceable toothbrush according to a second embodiment. FIG. 12 is an enlarged perspective view of the shaft portion of the brush body of the replaceable toothbrush of FIG. 11 . 12 is a cross-sectional view of the replaceable toothbrush shown in FIG. 11 along the line B-B. 12 is an enlarged side view showing the shaft insertion portion of the replaceable toothbrush of FIG. 11 as viewed from the opening side. FIG. FIG. 11 is a cross-sectional view of a mounting portion of a replaceable toothbrush according to another embodiment.

Below, an example of an embodiment of the replaceable toothbrush of the present invention will be described with reference to the drawings. Note that the following embodiment shows one aspect of the present invention, does not limit the present invention, and can be modified as desired within the scope of the technical concept of the present invention. In addition, in the following drawings, the scale and number of each structure are different from the actual structure in order to make each component easier to understand.

[First embodiment]
As shown in FIGS. 1 and 2, a replaceable toothbrush 1 of the first embodiment includes a brush body 2 and a replacement brush 3 that is detachably attached to the tip side of the brush body 2.

As shown in Figures 1, 2, and 3(A) to (C), the replacement brush 3 comprises an attachment part 6 attached to the tip side of the brush body 2, a head part 7 provided on the tip side of the attachment part 6, and a neck part 8 connecting the head part 7 and the attachment part 6. In the replaceable toothbrush 1, bristle bundles 12 are planted in a plurality of bristle planting holes 10 formed in the bristle planting surface 7a of the head part 7 to form the bristle planting part 14, making it possible to brush the teeth.

In the following description, the side of the head portion 7 on which the bristle surface 7a is provided (the bristle surface side) is referred to as the front side of the replaceable toothbrush 1, and the side opposite the side on which the bristle surface 7a of the head portion 7 faces is referred to as the back side of the replaceable toothbrush 1.
In addition, the direction in which the brush body 2 extends is the long axis direction,
A direction perpendicular to the long axis direction and extending from an opening on the outer circumferential surface 6 a side of the mounting portion 6 in the shaft insertion portion 16 described later toward the bottom is defined as a short axis direction.
The direction parallel to the bristle implantation surface 7a and perpendicular to the longitudinal direction is the width direction of the replaceable toothbrush 1,
The direction perpendicular to the bristle surface 7a is the thickness direction of the replaceable toothbrush 1.
The side where the replacement brush 3 is provided is the leading end side, and the side where the brush body 2 is provided is the trailing end side.

(Head part 7)
The replacement brush 3 of this example has a head portion 7 that is generally rectangular in front view and is provided on the tip side of a cylindrical mounting portion 6 with a neck portion 8 interposed therebetween.
Boundary P1 (not shown) between the head and neck portions is the end point of the curve that forms the corner cutting near the neck portion 8 in the planar shape of head portion 7, i.e., the position where the bending direction of the curve that forms the corner cutting changes. In other words, boundary P1 between the head and neck portions is the position where the curve or straight line that forms both edges where the width of the corner cutting portion near the neck portion in the head portion in planar view changes to a curve or straight line that widens in width, or a straight line of the same width.

The shape of the head portion 7 is not limited to a generally rectangular shape when viewed from the front, and any known shape can be used without restriction. The dimensions of the head portion 7 can be set appropriately, for example, the length can be 10 mm or more and 33 mm or less, the width can be 7 mm or more and 13 mm or less, and the thickness can be 2 mm or more and 5 mm or less.

The manner in which the bristle bundle 12 is planted in the bristle implantation hole 10 formed in the bristle implantation surface 7a of the head portion 7 is not particularly limited. For example, a plurality of bristles (filaments) may be bundled together and folded in half, with a metal stopper (not shown) called a flat wire sandwiched between them, before being driven into the bristle implantation hole 10.

The number of the tufting holes 10 is not particularly limited and may be, for example, from 10 to 40. The arrangement pattern of the tufting holes 10 is not particularly limited and may be appropriately designed.
The diameter of the tufting hole 10 can be set appropriately, for example, to be 1.2 mm or more and 3.0 mm or less.

The bristles constituting the bristle bundle 12 are not particularly limited, and examples thereof include straight bristles, bristles whose diameter gradually decreases toward the tip (tapered bristles), and bristles with branched ends. The material of the bristles is not particularly limited, and examples thereof include polyamide, polybutylene terephthalate, polytrimethylene terephthalate, polyolefin (polypropylene, etc.), styrene-based elastomers, polyester-based elastomers, and polyurethane-based elastomers.
The dimensions of the bristles can be set appropriately, for example, the bristles length can be 6 mm or more and 13 mm or less, and the bristles diameter can be 4 mil or more and 13 mil or less.

(Neck portion 8)
The shape of the neck portion 8 is not particularly limited, and any known shape can be adopted without restriction.
The neck portion 8 connecting the head portion 7 and the mounting portion 6 extends from a boundary P1 between the head portion and the neck portion toward the mounting portion 6 with approximately the same diameter, and then expands in diameter to reach a boundary P2 (not shown) with the mounting portion 6. The boundary P2 is the end point of the expansion of the neck portion 8, that is, the end point of the straight lines forming both edges of the widening portion in a plan view, or the position where the bending direction of the curved lines forming both edges of the widening portion changes. In the case of Figure 1, the boundary P2 between the neck portion and the handle portion is the position where the straight lines or curved lines forming both edges of the widening portion in a plan view change to a curved line where the width gradually narrows.

The dimensions of the neck portion 8 can be set appropriately, for example, the length can be 40 mm or more and 70 mm or less, the width can be 3 mm or more and 5 mm or less, and the thickness can be 3 mm or more and 5 mm or less.

(Mounting part 6)
The shape of the mounting portion 6 is not limited to a cylindrical shape, and may be, for example, a truncated cone shape.
In the replaceable toothbrush 1, a groove-shaped shaft insertion portion 16 that opens at the outer circumferential surface 6a and rear end surface 6b of the mounting portion 6 and extends in the longitudinal direction is formed in the mounting portion 6 of the replacement brush 3. In this example, the shaft insertion portion 16 is formed so as to open on the side surface of the outer circumferential surface 6a of the mounting portion 6 when the replacement brush 3 is viewed from the front side. Note that the shaft insertion portion 16 may be formed so as to open on the front side or rear side of the outer circumferential surface 6a of the mounting portion 6.

(Shaft insertion portion 16)
The shaft insertion portion 16 is formed in a groove shape for receiving therein a shaft portion 5 and a shielding portion 9 of the brush body 2, which will be described later, as shown in Figs.
The length in the longitudinal direction of the shaft insertion portion 16 need only be long enough to accommodate the shaft portion 5 and the shielding portion 9 therein, and it is preferable that the length be the same as the length of the shielding portion 9 since the shaft insertion portion 16 and the shaft portion 5 are less noticeable when the replacement brush 3 is attached.
The length of the shaft insertion portion 16 in the major axis direction is preferably 5 mm or more and 40 mm or less, and more preferably 10 mm or more and 25 mm or less.

The length of the shaft insertion portion 16 in the direction perpendicular to the minor axis direction as viewed from the major axis direction is defined as L1 as shown in Fig. 3(B), and the length of the shaft insertion portion 16 in the minor axis direction, i.e., the depth of the shaft insertion portion 16 from the opening on the outer circumferential surface 6a side of the mounting portion 6 toward the bottom, is defined as L2 as shown in Fig. 3(A). In this case, L1 and L2 have a relationship of L1<L2.
L1 may be any length that is sufficient to accommodate the shaft portion 5 and the shielding portion 9 therein, and since the shaft insertion portion 16 and the shaft portion 5 are less noticeable when the replacement brush 3 is attached, it is preferable that the length be the same as the length perpendicular to the minor axis direction of the shielding portion 9 when viewed from the major axis direction.
L2 may be any length that can receive both the shaft portion 5 and the shielding portion 9, and is preferably a length that extends from the outer peripheral surface 6a of the mounting portion 6 to the central axis.

The resin constituting the attachment portion 6, head portion 7, and neck portion 8 may be only hard resin, only soft resin, or both hard and soft resin. In terms of suppressing the amount of deflection during brushing, it is preferable to use only hard resin as the resin constituting the attachment portion 6, head portion 7, and neck portion 8. The resin constituting the attachment portion 6, head portion 7, and neck portion 8 may be one type, or two or more types.

Examples of hard resins include polypropylene (PP), polyacetal (POM), polycyclohexylene dimethylene terephthalate (PCT), polyethylene terephthalate (PET), polycarbonate (PC), acrylonitrile-butadiene-styrene resin (ABS), and polymethyl methacrylate (PMMA). Biodegradable resins, plant-derived resins, paper-blended resins, plant-blended resins, and the like may also be used. Among these, PP is preferred in terms of excellent moldability and cost advantages.
Examples of the soft resin include olefin-based elastomers, styrene-based elastomers, polyester-based elastomers, and polyurethane-based elastomers.

As shown in FIG. 6 , a leaf spring portion 30 is provided inside the mounting portion 6 , into which the shaft portion 5 (described later) inserted into the shaft insertion portion 16 is fitted.
The leaf spring portion 30 includes a base 31 and a pair of spring pieces 32, 33 protruding from the base 31. When viewed in the longitudinal direction, the base 31 of the leaf spring portion 30 is located on the opposite side to the bottom opening side of the shaft insertion portion 16. Furthermore, the pair of spring pieces 32, 33 each protrude in an arc shape from the base 31 toward the opening side of the shaft insertion portion 16, and their tip portions protrude into the shaft insertion portion 16 from the inner wall surfaces on both opposing sides of the shaft insertion portion 16.

The minimum thickness of each of the spring pieces 32, 33 at the opening side (tip portion) of the shaft insertion portion 16 is preferably 0.5 mm to 4.0 mm, more preferably 1.0 mm to 2.5 mm. If the minimum thickness of the spring pieces 32, 33 is equal to or greater than the lower limit of the range, the retention force of the shaft portion 5 is sufficient, making it easier to prevent the replacement brush 3 from coming off unexpectedly during use. If the minimum thickness of the spring pieces 32, 33 is equal to or less than the upper limit of the range, the elasticity of the spring pieces 32, 33 is sufficient, making it easier to fit the shaft portion 5 into the leaf spring portion 30.

(Brush body 2)
As shown in FIGS. 1, 2 and 4, the brush body 2 includes a handle portion 4 and a shaft portion 5 extending from a tip end 4a of the handle portion 4 in the longitudinal direction.
In addition, the brush body 2 further includes a shielding portion 9 extending in the longitudinal direction from the tip 4a of the handle portion 4 and positioned closer to the outer circumferential surface 4b of the handle portion 4 than the shaft portion 5 when viewed from the tip side.
As shown in FIG. 4 , in the replaceable toothbrush 1 , a connector 20 is formed by connecting the shielding portion 9 extending from the tip side of the handle portion 4 and the shaft portion 5 via a connecting portion 18 .

As shown in FIG. 5, when attaching the replacement brush 3 to the tip side of the brush body 2, the replacement brush 3 and the brush body 2 are moved toward each other in the short axis direction, and the shaft 5 is inserted into the shaft insertion part 16 from the opening on the outer circumferential surface 6a side of the attachment part 6. At this time, as shown in FIG. 1 and FIG. 2, the connector 20 is inserted into the shaft insertion part 16 from the shaft 5 side. That is, both the shaft 5 and the shielding part 9 are inserted into the shaft insertion part 16 so that the shaft 5 is on the central axis side (bottom side) of the shaft insertion part 16. When the replacement brush 3 is attached to the tip side of the brush body 2, the central axis of the brush body 2 and the central axis of the replacement brush 3 are aligned. In addition, when the replacement brush 3 is attached to the tip side of the brush body 2, it is preferable that the shaft 5 is located at the bottom of the shaft insertion part 16 when viewed from the opening on the outer circumferential surface 6a side of the attachment part 6.

When removing the replacement brush 3, the replacement brush 3 and the brush body 2 are moved away from each other in the short axis direction, and are removed from the shaft insertion portion 16 through the opening on the outer circumferential surface 6a side of the attachment portion 6. In this way, in the replaceable toothbrush 1, the replacement brush 3 and the brush body 2 are moved in the short axis direction when replacing the replacement brush 3. Therefore, there is no action to pull the replacement brush 3 out of the brush body 2 in the long axis direction when replacing it, and the hand holding the replacement brush 3 is less likely to slip in the long axis direction, which prevents the hand from accidentally touching the head portion 7.

When the replacement brush 3 is attached to the brush body 2, the shielding portion 9 is located inside the shaft insertion portion 16, closer to the opening than the shaft portion 5. Therefore, when viewed from the opening on the outer circumferential surface 6a side of the attachment portion 6, at least a portion of the shaft portion 5 inside the shaft insertion portion 16 is shielded by the shielding portion 9, making the shaft portion 5 less noticeable. In addition, because the portion of the shaft insertion portion 16 closer to the opening than the shaft portion 5 is filled with the shielding portion 9, the shaft insertion portion 16 is also less noticeable. For these reasons, users are more likely to feel that the replaceable toothbrush 1 is hygienic.

(Shaft portion 5)
The shaft portion 5 in this example is cylindrical and is provided at the tip 4a of the handle portion 4 so as to coincide with the central axis of the handle portion 4. The shape of the shaft portion 5 is not limited to a cylindrical shape, and may be, for example, a square prism shape, as long as the replacement brush 3 can be attached to the brush body 2 by inserting it into the shaft insertion portion 16. The position of the shaft portion 5 at the tip 4a of the handle portion 4 is not limited to a position that coincides with the central axis of the handle portion 4, and may be offset from the central axis.

The length of the shaft 5 in the longitudinal direction is preferably 5 mm or more and 40 mm or less, and more preferably 10 mm or more and 25 mm or less. If the length of the shaft 5 in the longitudinal direction is equal to or greater than the lower limit of the above range, the retention force between the brush body and the replacement brush will be weak, and the replacement brush will be more likely to come off during use. If the length of the shaft 5 in the longitudinal direction is equal to or less than the upper limit of the above range, it will be difficult to fit the replacement brush into the brush body.

The length of the connector 20 in the minor axis direction is L3 as shown in Fig. 4, and the length of the shaft portion 5 in the direction perpendicular to the minor axis direction as seen from the major axis direction is L4 as shown in Fig. 4. At this time, L3 and L4 have a relationship of L4<L3.
L3 is preferably more than 1.0 mm and not more than 10 mm. If L3 is equal to or greater than the lower limit of the range, the retention force between the brush body and the replacement brush is weakened, and the replacement brush is likely to come off during use. If L3 is equal to or less than the upper limit of the range, it is difficult to fit the replacement brush into the brush body.
L4 is preferably 1.0 mm or more and 5.0 mm or less, and more preferably 1.5 mm or more and 3.5 mm or less.
From the viewpoint of ease of insertion and fixation after insertion, the relationship between L1 and L4 is preferably L1≧L4, and the relationship between L2 and L3 is preferably L2≧L3.

(Shielding portion 9)
The shielding portion 9 in this example is cylindrical, and is provided so that the outer peripheral surface of the shielding portion 9 coincides with the outer peripheral surface 4b of the handle portion 4 in a plan view seen from the tip side. Note that the shape of the shielding portion 9 is not limited to a cylindrical shape as long as it can shield the shaft portion 5 when inserted into the shaft insertion portion 16, and may be, for example, a square prism shape.

The position of the shielding portion 9 at the tip 4a of the handle portion 4 may be closer to the outer peripheral surface 4b of the handle portion 4 than the shaft portion 5, and is preferably closer to the outer peripheral surface 4b of the handle portion 4 in order to make the shaft insertion portion 16 less noticeable. The position of the shielding portion 9 may be closer to the center than the outer peripheral surface 4b of the handle portion 4.

The length of the shielding portion 9 in the longitudinal direction is preferably the same as the length of the shaft portion 5 in the longitudinal direction or longer than that of the shaft portion 5, within the range in which the shielding portion 9 can be inserted into the shaft insertion portion 16. This allows the shaft portion 5 inside the shaft insertion portion 16 to be shielded by the shielding portion 9, making the shaft portion 5 less noticeable.
The length of the shielding portion 9 in the minor axis direction is preferably equal to or greater than the length of the shank 5 in the minor axis direction within the range that it can be inserted into the shaft insertion portion 16. The length of the shielding portion 9 in the direction perpendicular to the minor axis direction as viewed from the major axis direction is preferably equal to or greater than the length L4 of the shank 5 within the range that it can be inserted into the shaft insertion portion 16. This allows the shank 5 inside the shaft insertion portion 16 to be shielded by the shielding portion 9, making the shank 5 less noticeable.

As shown in FIG. 7, in the replaceable toothbrush 1, it is preferable that the shape of the opening side of the outer circumferential surface 9a of the shielding portion 9 when inserted into the shaft insertion portion 16 conforms to the shape of the outer circumferential surface 6a of the attachment portion 6, so that when the replacement brush 3 is attached, there is no step between the outer circumferential surface 9a of the shielding portion 9 and the outer circumferential surface 6a of the attachment portion 6, and the shaft insertion portion 16 is completely filled. This makes the shaft insertion portion 16 even less noticeable when the replacement brush 3 is attached, making the user feel that the replaceable toothbrush 1 is more hygienic.

(Connecting portion 18)
4, in the long axis direction, the length of the connecting part 18 is shorter than the long axis lengths of the shaft part 5 and the shielding part 9, and a recessed part 22 is formed between the shielding part 9 and the shaft part 5 on the tip side of the connecting body 20. In addition, the length of the connecting part 18 in a direction perpendicular to the short axis direction as viewed from the long axis direction is shorter than the length L4 of the shaft part 5 and the length of the shielding part 9 in a direction perpendicular to the short axis direction as viewed from the long axis direction, and a recessed part 24 extending in the long axis direction is formed between the shielding part 9 and the shaft part 5 on the side side of the connecting body 20.

As shown in FIG. 6, where the recess 22 is formed in the connecting body 20, the tip portion of the shaft 5 exists independently, and the tip portion of the shaft 5 is fitted into the leaf spring portion 30 within the shaft insertion portion 16. This makes it difficult for the shaft 5 to come off unexpectedly from the shaft insertion portion 16, so that the replacement brush 3 can be attached stably. In the replaceable toothbrush 1, the recess 22 is formed on the tip side of the connecting body 20, so that the tip portion of the shaft 5 can be firmly surrounded and held by the pair of spring pieces 32, 33 of the leaf spring portion 30, making the replacement brush 3 more stably attached.

In FIG. 4, the difference ΔH in the length in the longitudinal direction between the shaft portion 5 and the connecting portion 18, i.e., the depth of the recessed portion 22, is preferably 20 mm or less, and more preferably 10 mm to 15 mm. If the difference ΔH in the length between the shaft portion 5 and the connecting portion 18 is equal to or less than the upper limit of the range, the shaft portion 5 can be easily held by the leaf spring portion 30. If the difference ΔH in the length between the shaft portion 5 and the connecting portion 18 is equal to or greater than the lower limit of the range, the holding force of the leaf spring portion 30 on the shaft portion 5 is improved, and the replacement brush 3 can be more stably attached.

The resin constituting the brush body 2 may be only hard resin, only soft resin, or both hard and soft resins. In terms of suppressing the amount of deflection during brushing, it is preferable to use only hard resin as the resin constituting the brush body 2. In particular, hard resin is preferable as the resin constituting the shielding portion 9, shaft portion 5, and connecting portion 18. The resin constituting the brush body 2 may be one type, or two or more types.

It is preferable that the color of the shielding portion 9 is the same as the color of the attachment portion 6. This makes the shaft insertion portion 16 even less noticeable when the replacement brush 3 is attached, making it more likely for the user to feel that it is hygienic.

The manufacturing method of the replaceable toothbrush 1 is not particularly limited. For example, examples of molding methods for the brush body 2, the attachment part 6 of the replacement brush 3, the neck part 8, and the head part 7 include injection molding and blow molding, with injection molding being preferred. The runner for injection molding may be a cold runner or a hot runner, with a hot runner being preferred. The gate for injection molding is not particularly limited, with a direct gate being an example.

As described above, in the replaceable toothbrush 1, when replacing the replacement brush 3, the replacement brush 3 and the brush body 2 are moved in the short axis direction relative to each other to attach and detach the replacement brush 3, so there is no action of pulling the replacement brush 3 out of the brush body 2 in the long axis direction. Therefore, when replacing the replacement brush 3, the hand holding the replacement brush 3 is less likely to slip in the long axis direction, so that the hand is prevented from accidentally touching the head part 7. In addition, when the replacement brush 3 is attached to the brush body 2, the shielding part 9 is located closer to the opening side than the shaft part 5 in the shaft insertion part 16. Therefore, when viewed from the opening on the outer circumferential surface 6a side of the attachment part 6, at least a part of the shaft part 5 in the shaft insertion part 16 is shielded by the shielding part 9, and the part of the shaft insertion part 16 closer to the opening side than the shaft part 5 is filled with the shielding part 9. As a result, the shaft part 5 and the shaft insertion part 16 are less noticeable when the replacement brush 3 is attached, so that the user feels that the replaceable toothbrush 1 is hygienic.

The replaceable toothbrush of the first embodiment is not limited to the replaceable toothbrush 1 described above.
For example, a recess may be formed only on one of the tip side and side side of the connecting body in which the shaft part and the shielding part are connected. Specifically, for example, as shown in Fig. 8, the brush body 2 may include a connecting body 20A in which the shaft part 5 and the shielding part 9 are connected by a connecting part 18A of the same length as them, and the recess 24 is formed only in the part between the shaft part 5 and the shielding part 9 on the side side. In the case of the connecting body 20A, as in the case of the connecting body 20, the shaft part 5 and the shaft insertion part 16 are less noticeable when the replacement brush 3 is attached, so that the user feels that the replaceable toothbrush 1 is hygienic.

As shown in FIG. 9, even in this embodiment, the replacement brush 3 can be stably attached to the brush body 2 by fitting the shaft 5 into the leaf spring 30 at the portion where the recess 24 of the connecting body 20A is formed. Note that in the connecting body 20A, the recess 24 is formed entirely from the tip to the rear end in the longitudinal direction, but the recess on the side of the connecting body may be formed partially in the longitudinal direction.

The connecting body in which the shaft portion and the shielding portion are connected may have no recesses on either the tip or side. For example, as shown in FIG. 10, it may be a flat connecting body 20B in which the shaft portion 5 and the shielding portion 9 are connected and integrated. In the case of connecting body 20B, as in the case of connecting body 20, the shaft portion 5 and shaft insertion portion 16 are less noticeable when the replacement brush 3 is attached, so that the user feels that the replaceable toothbrush 1 is hygienic.

As shown in Fig. 10, the ratio of the length L in the direction perpendicular to the minor axis direction of the connecting body 20B to the minimum length D in the minor axis direction is preferably 1.0 to 10, more preferably 1.3 to 4.6. If the ratio is equal to or greater than the lower limit of the range, the retention force of the brush body and the replacement brush is weakened, and the replacement brush is likely to come off during use. If the ratio is equal to or less than the upper limit of the range, it is difficult to fit the replacement brush into the brush body.
The length of L may be the same as L3 described above, and the length of D may be the same as L4.

[Second embodiment]
As shown in FIG. 11, a replaceable toothbrush 41 of the second embodiment includes a brush body 42 and a replacement brush 43 detachably attached to the tip side of the brush body 2 .

As shown in Figure 12, the brush main body 42 is similar to the brush main body 2 of the first embodiment, except that it does not have a shielding portion 9 or a connecting portion 18, and only the shaft portion 5 is provided at the tip 4a of the handle portion 4.
11 and 13, the replacement brush 43 is similar to the replacement brush 3 of the first embodiment, except that a leaf spring portion 50 into which the shaft portion 5 inserted into the shaft insertion portion 16 is fitted is provided instead of the leaf spring portion 30. The same parts in Figures 11 to 13 as those in Figures 1, 4, and 6 are designated by the same reference numerals and will not be described.

The leaf spring portion 50 has a base 51 and a pair of spring pieces 52, 53. The base 51 is columnar and extends in the longitudinal direction, and is located on the opposite side to the bottom opening of the shaft insertion portion 16 when viewed from the longitudinal direction. The pair of spring pieces 52, 53 are each plate-shaped and extend in the longitudinal direction, and protrude in an arc shape from the base 51 to the opening side of the shaft insertion portion 16 when viewed from the longitudinal direction, with their tip portions protruding into the shaft insertion portion 16 from the inner wall surfaces on both opposing sides of the shaft insertion portion 16.

In the replaceable toothbrush 41, similar to the replaceable toothbrush 1, the shaft 5 is inserted into the shaft insertion portion 16 from the opening on the outer circumferential surface 6a side of the attachment portion 6, thereby attaching the replacement brush 43 to the tip side of the brush body portion 42. As shown in FIG. 13, when the replacement brush 43 is attached to the tip side of the brush body portion 42, the shaft 5 inserted into the shaft insertion portion 16 is fitted into the leaf spring portion 50. When removing the replacement brush 43, the replacement brush 43 is moved away from the brush body portion 42 in the short axis direction, and the shaft 5 is detached from the leaf spring portion 50 and pulled out to the outside of the shaft insertion portion 16.

In this way, in the replaceable toothbrush 41, as in the replaceable toothbrush 1, there is no action of pulling out the replacement brush 43 from the brush body 42 in the longitudinal direction when replacing the toothbrush, and the hand holding the replacement brush 43 is less likely to slip in the longitudinal direction, so that the hand is prevented from accidentally touching the head 7. Also, as shown in Figures 13 and 14, when the replacement brush 3 is attached, a pair of spring pieces 52, 53 surround the periphery of the shaft 5 of the shaft insertion part 16 from both sides, and the tip parts of the pair of spring pieces 52, 53 are located closer to the opening side than the shaft 5 of the shaft insertion part 16. The tip parts of the pair of spring pieces 52, 53 function as shielding parts 9A, 9A, and when viewed from the opening on the outer circumferential surface 6a side of the attachment part 6, at least a part of the shaft 5 in the shaft insertion part 16 is shielded by the shielding parts 9A, 9A, making the shaft 5 less noticeable. In addition, because the portion of the shaft insertion portion 16 closer to the opening than the shaft portion 5 is covered by the shielding portions 9A, 9A, the shaft insertion portion 16 is also less noticeable. For these reasons, users feel that the replaceable toothbrush 41 is hygienic.

Since the shaft portion 5 is less noticeable when viewed from the opening on the outer peripheral surface 6a side of the mounting portion 6, it is preferable that the length in the longitudinal direction of the pair of spring pieces 52, 53 of the leaf spring portion 50 is equal to or greater than the length in the longitudinal direction of the shaft portion 5.

In this example of the leaf spring portion 50, the opposing surface 52a of the spring piece 52 facing the spring piece 53 and the opposing surface 53a of the spring piece 53 facing the spring piece 52 are both parallel in the radial direction from the opening on the outer circumferential surface 6a side of the mounting portion 6 toward the central axis.
Also, as shown in Figure 13, in the radial direction from the opening on the outer circumferential surface 6a side of the mounting portion 6 toward the central axis, the maximum length d1 in the minor axis direction of the parallel opposing surfaces 52a, 53a of a pair of spring pieces 52, 53 is greater than the maximum length d2 in the minor axis direction of the shaft portion 5.

The ratio (d1/d2) of the maximum length d1 in the minor axis direction of the parallel opposing surfaces 52a, 53a of the pair of spring pieces 52, 53 to the maximum length d2 in the minor axis direction of the shaft portion 5 is preferably 1.5 to 9.0, more preferably 2.0 to 4.6. If d1/d2 is equal to or greater than the lower limit of the range, the shaft portion 5 is difficult to see from the opening on the outer peripheral surface 6a side of the mounting portion 6, which makes the user feel more hygienic. If d1/d2 is equal to or less than the upper limit of the range, the shaft portion 5 can be easily fitted into the leaf spring portion 50.
d1 is preferably 1.5 mm or more and 9.0 mm or less, and more preferably 3.0 mm or more and 7.0 mm or less.
d2 is preferably 1.0 mm or more and 5.0 mm or less, and more preferably 1.5 mm or more and 3.5 mm or less.

The ratio (d4/d3) of the distance d4 between the opposing surface 52a of the spring piece 52 and the opposing surface 53a of the spring piece 52 to the maximum length d3 in the direction perpendicular to the minor axis direction of the shaft portion 5 as viewed from the major axis direction is preferably 0.1 to 0.5, more preferably 0.2 to 0.4. If d4/d3 is equal to or less than the upper limit of the range, the shaft portion 5 is difficult to see when viewed from the opening on the outer circumferential surface 6a side of the mounting portion 6, which makes the user feel more hygienic. If d4/d3 is equal to or more than the lower limit of the range, the shaft portion 5 can be easily fitted into the leaf spring portion 50.
d3 is preferably 1.0 mm or more and 5.0 mm or less, and more preferably 1.5 mm or more and 3.5 mm or less.
d4 is preferably 0.5 mm or more and 2.5 mm or less, and more preferably 0.6 mm or more and 2.0 mm or less.

The minimum thickness of the spring pieces 52, 53 as viewed in the longitudinal direction is preferably 0.5 mm to 4.0 mm, more preferably 1.5 mm to 3.5 mm. If the minimum thickness of the spring pieces 52, 53 is equal to or greater than the lower limit of the range, the holding force of the shaft 5 is sufficient, making it easier to prevent the replacement brush 43 from coming off unexpectedly during use. If the minimum thickness of the spring pieces 52, 53 is equal to or less than the upper limit of the range, the elasticity of the spring pieces 52, 53 is sufficient, making it easier to fit the shaft 5 into the leaf spring portion 50.

As described above, in the replaceable toothbrush 41, as in the replaceable toothbrush 1, the hand holding the replacement brush 43 is less likely to slip in the longitudinal direction when replacing the replacement brush 43, which prevents the hand from accidentally touching the head portion 7. In addition, the tip portions of the pair of spring pieces 52, 53 of the leaf spring portion 50 serve as shielding portions 9A, 9A, which shield the shaft portion 5, making the shaft portion 5 and the shaft insertion portion 16 less noticeable, which the user feels is more hygienic.

The replaceable toothbrush of the second embodiment is not limited to the replaceable toothbrush 41 described above. For example, as shown in FIG. 15, it may be a replacement brush 43 that includes a leaf spring portion 50A instead of the leaf spring portion 50. The leaf spring portion 50A includes a pair of spring pieces 54, 55 instead of the pair of spring pieces 52, 53.

When viewed from the longitudinal direction, the spring piece 54 has a tip-side inclined surface 54a that approaches the other spring piece 55 from the tip to the base end. The spring piece 54 also has a base-side inclined surface 54b that moves away from the other spring piece 55 from the rear end of the tip-side inclined surface 54a toward the base 51. Similarly, the spring piece 55 has a tip-side inclined surface 55a that moves toward the other spring piece 54 from the tip to the base end. The spring piece 55 also has a base-side inclined surface 55b that moves away from the other spring piece 54 from the rear end of the tip-side inclined surface 55a toward the base 51.

Except when the replacement brush 43 is being attached or detached, the rear end of the tip-side inclined surface 54a of the spring piece 54 and the rear end of the tip-side inclined surface 55a of the spring piece 55 are in contact with each other, and the leaf spring portion 50A is in a closed state. In other words, the pair of tip-side inclined surfaces 54a and 55a act as shielding portions 9B, 9B to shield the shaft portion 5. As a result, the shaft portion 5 inside the shaft insertion portion 16 cannot be seen from the opening on the outer circumferential surface 6a side of the attachment portion 6, which makes the user feel that it is hygienic.

In the case of the leaf spring portion 50A, the tip side inclined surfaces 54a, 55a of the spring pieces 54, 55 are pushed open from the outside by the shaft portion 5 inserted into the shaft insertion portion 16 and pushed toward the leaf spring portion 50A, so that the pair of spring pieces 54, 55 are pushed open from the outside. Therefore, even if the pair of spring pieces 54, 55 are closed before the replacement brush 43 is attached, it is easy to fit the shaft portion 5 into the leaf spring portion 50A.

Furthermore, when removing the shaft 5 fitted into the leaf spring 50A, the shaft 5 to be removed presses the base-side inclined surfaces 54b, 55b of the spring pieces 54, 55, pushing the pair of spring pieces 54, 55 open from the inside. Therefore, even if the pair of spring pieces 54, 55 are closed when the replacement brush 43 is attached, the shaft 5 can be easily removed from the leaf spring 50A. In this way, by using the leaf spring 50A, it is possible to easily attach and detach the replacement brush 3 while making the shaft 5 invisible.
Furthermore, in the leaf spring portion 50A, the tip side inclined surfaces 54a, 55a and base side inclined surfaces 54b, 55b of the spring pieces 54, 55 act as guides when inserting or removing the shaft portion 5. This makes it easy to insert the shaft portion 5 into or remove it from the leaf spring portion 50.

In the radial direction from the opening on the outer surface 6a side of the mounting portion 6 toward the central axis, the distance d5 from the contact point between the spring pieces 54 and 55 to the opening of the shaft insertion portion 16 is greater than the distance d6 from the tips of the pair of spring pieces 54, 55 to the opening of the shaft insertion portion 16.
The distance d6 is preferably 1.0 mm or more, and more preferably 1.5 mm or more and 3.0 mm or less. If the distance d6 is less than the lower limit of the range, the shaft portion 5 cannot be removed from the spring pieces 54, 55. If the distance d6 exceeds the upper limit of the range, it becomes difficult to attach and detach the shaft portion 5.

Distance d5 is greater than distance d6, and is preferably 1.0 mm to 9.0 mm, and more preferably 3.0 mm to 7.0 mm. If distance d5 is equal to or greater than the lower limit of the range, the tip side inclined surfaces 54a, 55a and base side inclined surfaces 54b, 55b of spring pieces 54, 55 act as guides. If distance d5 is equal to or less than the upper limit of the range, fitting and removing shaft portion 5 into leaf spring portion 50 becomes easier.

The leaf spring portion 50A may be such that only one of the pair of spring pieces 54, 55 has a tip-side inclined surface. The leaf spring portion may have only a tip-side inclined surface and not a base-side inclined surface.
In addition, the present invention can be implemented in various forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention.

1, 41...replaceable toothbrush, 2, 42...brush body, 3, 43...replacement brush, 4...handle, 5...shaft, 6...attachment, 6a...outer periphery, 6b...rear end, 7...head, 8...neck, 9, 9A...shielding, 10...hair implantation hole, 12...hair bundle, 14...hair implantation, 16...shaft insertion, 18...connecting, 20...connecting body, 22, 24...recess, 30...leaf spring, 31...base, 32, 33...spring piece, 50...leaf spring, 52-55...spring piece, 54a, 55a...tip side inclined surface, 54b, 55b...base side inclined surface.

Claims (5)

A brush body;
A replacement brush that is detachably attached to the tip side of the brush body;
A replaceable toothbrush comprising:
The brush body includes a handle portion and a shaft portion extending in a longitudinal direction from a tip of the handle portion,
The replacement brush includes an attachment portion attached to a tip side of the brush body,
The mounting portion is formed with a groove-shaped shaft insertion portion that opens on an outer circumferential surface and a rear end surface of the mounting portion and extends in a longitudinal direction,
The shaft portion is inserted into the shaft insertion portion from an opening on the outer circumferential surface side of the attachment portion, whereby the replacement brush is attached to the brush body portion,
When the replacement brush is attached to the brush body, the shaft portion in the shaft insertion portion is covered by a covering portion when viewed from an opening on an outer circumferential surface side of the attachment portion,
the shielding portion extends in a longitudinal direction from a tip of the handle portion and is disposed closer to an outer circumferential surface of the handle portion than the shaft portion;
The shielding portion and the shaft portion are connected to form a connecting body,
a recess is formed between the shielding portion and the shaft portion on at least one of the tip side and the side surface side of the connector,
a leaf spring portion into which the shaft portion inserted into the shaft insertion portion is fitted is provided inside the mounting portion,
The connector is inserted into the shaft insertion portion from an opening on the outer circumferential surface side of the mounting portion, and both the shielding portion and the shaft portion are inserted into the shaft insertion portion, thereby mounting the replacement brush to the brush body portion,
A replaceable toothbrush, wherein the shaft portion of the connector inserted into the shaft insertion portion, where the recessed portion is formed, is fitted into the leaf spring portion. The replaceable toothbrush according to claim 1, in which the recess is formed between the shielding part on the tip side of the connector and the shaft part, and the tip part of the shaft part is fitted into the leaf spring part. A brush body;
A replacement brush that is detachably attached to the tip side of the brush body;
A replaceable toothbrush comprising:
The brush body includes a handle portion and a shaft portion extending in a longitudinal direction from a tip of the handle portion,
The replacement brush includes an attachment portion attached to a tip side of the brush body,
The mounting portion is formed with a groove-shaped shaft insertion portion that opens on an outer circumferential surface and a rear end surface of the mounting portion and extends in a longitudinal direction,
The shaft portion is inserted into the shaft insertion portion from an opening on the outer circumferential surface side of the attachment portion, whereby the replacement brush is attached to the brush body portion,
a leaf spring portion into which the shaft portion inserted into the shaft insertion portion is fitted is provided inside the mounting portion,
The leaf spring portion includes a pair of spring pieces surrounding the shaft portion from both sides when viewed in the longitudinal direction,
When the replacement brush is attached to the brush body, the pair of spring pieces act as a shielding portion, shielding at least a portion of the shaft portion within the shaft insertion portion, as viewed from the opening on the outer peripheral surface side of the attachment portion. The pair of spring pieces each have a facing surface that faces each other and is parallel to a radial direction from an opening on an outer peripheral surface side of the mounting portion toward a central axis,
The replaceable toothbrush according to claim 3 , wherein a length of the opposing surface is greater than a length of the shaft portion in the radial direction. The replaceable toothbrush according to claim 3, in which at least one of the pair of spring pieces has an inclined surface that approaches the other spring piece from the tip to the base end when viewed in the longitudinal direction.

Images