Patent Description:
Conventionally, an interdental cleaning tool for cleaning an interdental space is known. For example, <CIT> discloses an interdental cleaning tool including a base structure portion made of synthetic resin, and a soft portion made of elastomer. The base structure portion includes a core base structure portion having a shape insertable in an interdental space, and a handling base structure portion having a shape that can be held by fingers. The soft portion includes a covering portion that covers an outer circumferential surface of the core base structure portion, and a plurality of protruding portions each provided on an outer circumferential surface of the covering portion. Each of the protruding portions has a shape extending outward from the outer circumferential surface of the covering portion in a direction perpendicularly intersecting an axial direction of the core base structure portion.

Further previously known examples of interdental cleaning tools are derivable from <CIT>, <CIT>, <CIT>, <CIT>, and <CIT>. <CIT> discloses an interdental cleaning tool comprising: a base portion including a shaft portion having a shape insertable in an interdental space; and a cleaning portion that covers at least a portion of the shaft portion and is capable of cleaning an interdental space, wherein the cleaning portion includes a plurality of bristles each having a shape protruding outward from an outer circumferential surface of the shaft, each of the plurality of bristles is a type of base end-oriented bristles having a shape tilting at an angle to a base end side of the shaft portion as advancing away from the outer circumferential surface of the shaft, the angle being formed between a plane perpendicularly intersecting an axial direction of the shaft portion and a direction in which the each of the plurality of bristles protrudes from the shaft.

In the interdental cleaning tool described in <CIT>, there have been the needs of enhancing the capability of scraping out deposits from an interdental space. Therefore, it has been considered to make protruding portions larger or give a higher rigidity to them. However, the employment of such configuration causes an increased resistance when inserting the tool in the interdental space or withdrawing the tool from the interdental space.

An object of the present invention is to provide an interdental cleaning tool that can reduce at least oner of the resistance against insertion in an interdental space and the resistance against withdrawal from an interdental space, and has a high capability of scraping out deposit from an interdental space.

To solve the problem described above, an interdental cleaning tool according to claim <NUM> is provided.

Specifically, the present invention provides an interdental cleaning tool including: a base portion including a shaft portion having a shape insertable in an interdental space; and a cleaning portion that covers at least a portion of the shaft portion and is capable of cleaning an interdental space, in which the cleaning portion includes a cleaning portion body that covers at least a portion of the shaft portion, and a plurality of bristles each having a shape protruding outward from an outer circumferential surface of the cleaning portion body, and each of the plurality of bristles is a type of base end-oriented bristles having a shape tilting at an angle θ to a base end side of the shaft portion as advancing away from the outer circumferential surface of the cleaning portion body. The angle θ is formed between a plane perpendicularly intersecting an axial direction of the shaft portion and a direction in which the each of the plurality of bristles protrudes from the cleaning portion body. The angle θ is set so as to be smaller along a direction from a top end side to a base end side of the cleaning portion body (<NUM>).

Since the plurality of bristles of the interdental cleaning tool includes at least one of the type of top end-oriented bristles and the type of base end-oriented bristles, at least one of the resistance against insertion of the cleaning portion in the interdental space and the resistance against withdrawal of the cleaning portion from the interdental space can be reduced, and the capability of the cleaning portion of scraping out deposit from the interdental space can be raised. Specifically, the top end-oriented bristle causes a high resistance against insertion in the interdental space while having a high capability of scraping out deposit during insertion in the interdental space, and causes a low resistance against withdrawal from the interdental space, compared to a conventional bristle having a shape protruding from an outer circumferential surface of a cleaning portion body in a direction perpendicularly intersecting an axial direction of a shaft portion (hereinafter referred to as "non-tilted bristle"). Meanwhile, the base end-oriented bristle causes a high resistance against withdrawal from the interdental space, but has a low resistance against insertion in the interdental space and has a high capability of scraping out deposit during withdrawal from the interdental space, compared to the conventional non-tilted bristle.

The cleaning portion of the interdental cleaning tool is made of a composite material containing elastomer and a reinforcing material.

In this way, the bristles are given a higher rigidity than a case where the cleaning portion is made only of elastomer. Accordingly, side surfaces of the teeth can effectively be cleaned.

Due to each of the plurality of bristles being the type of base end-oriented bristle, both reduction in the resistance against insertion in the interdental space and improvement in the scraping out capability during withdrawal from the interdental space can be achieved.

The present invention can provide, as described above, an interdental cleaning tool that can reduce at least one of a resistance caused when inserting the interdental cleaning tool in an interdental space and a resistance caused when withdrawing the interdental cleaning tool from an interdental space, and has a high capability of scraping out deposit from an interdental space.

An interdental cleaning tool <NUM> according to one embodiment of the present invention will be described with reference to <FIG>. As illustrated in <FIG>, the interdental cleaning tool <NUM> includes a base portion <NUM>, and a cleaning portion <NUM>.

The base portion <NUM> is made of a synthetic resin such as polypropylene, polyethylene, ABS, polybutylene terephthalate, polycarbonate, polyethylene terephthalate, polystyrene, and polyacetal. In the embodiment, the base portion <NUM> is made of polypropylene containing glass fibers by <NUM>% by weight. The base portion <NUM> includes a shaft portion <NUM>, and a grip portion <NUM>.

The shaft portion <NUM> has a shape extending straight in a specific direction (up-and-down direction in <FIG>) and insertable in an interdental space. The shaft portion <NUM> has a shape whose cross sectional size of the shaft portion <NUM> in a plane perpendicularly intersecting an axial direction of the shaft portion <NUM> (the up-and-down direction in <FIG>) gradually increases along a direction from a top end side to a base end side (opposite the top end side) of the shaft portion <NUM>. In the embodiment, the cross section of the shaft portion <NUM> in the plane is a circle. In other words, in the embodiment, the shaft portion <NUM> has a form of a column of which outer diameter gradually decreases from a base end portion to a top end portion of the shaft portion <NUM>. The cross section of the shaft portion <NUM> may be an oval shape or a polygonal shape.

The grip portion <NUM> extends in the axial direction of the shaft portion <NUM> away from the base end portion of the shaft portion <NUM> and has a shape that can be held by fingers. The grip portion <NUM> is formed into a flat shape.

The cleaning portion <NUM> is adapted for cleaning an interdental space and side surfaces of teeth. The cleaning portion <NUM> is made of a resin material having a lower hardness than the base portion <NUM>. Specifically, styrene elastomer is used as the resin material. Other materials, such as silicone, olefinic elastomer, and polyester elastomer, may also be used as the resin material. The cleaning portion <NUM> includes a cleaning portion body <NUM>, and a plurality of bristles <NUM>.

The cleaning portion body <NUM> covers at least a portion of the shaft portion <NUM> (the portion including the top end portion of the shaft portion <NUM>). The cleaning portion body <NUM> has a shape whose profile gradually increases along the direction from the top end side to the base end side of the shaft portion <NUM>.

Each of the bristles <NUM> is provided on an outer circumferential surface of the cleaning portion body <NUM>. The bristle <NUM> has a shape protruding outward from the outer circumferential surface of the cleaning portion body <NUM> in an intersecting direction that intersects the axial direction. In the embodiment, the bristle <NUM> has the shape of a cone. Each of the bristles <NUM> is a base end-oritented having a shape tilting to the base end side (lower side in <FIG>) of the shaft portion <NUM> as advancing away from the outer circumferential surface of the cleaning portion body <NUM>. As illustrated in <FIG>, a tilt angle θ of the base end oriented (angle between a plane perpendicularly intersecting the axial direction of the shaft portion <NUM> and a direction in which the base end-oriented bristle protrudes from the cleaning portion body <NUM>) is preferably set at a degree of 1or more and <NUM> or less, more preferably at <NUM> or more and <NUM> or less, furthermore preferably at <NUM> or more and <NUM> or less, and particularly preferably at <NUM> or more and <NUM> or less. The direction in which the base end-oriented bristle protrudes from the cleaning portion body <NUM> is the direction along the axis of the base end-oriented bristle.

The bristles <NUM> have respectively such shapes that their protruding lengths from the cleaning portion body <NUM> gradually increase along the direction from the top end side to the base end side of the shaft portion <NUM>. As illustrated in <FIG>, the bristles <NUM> are provided at positions spaced from one another along a circumferential direction of the cleaning portion body <NUM> in a plan view. Specifically, the bristles <NUM> are arranged at an interval of <NUM> degrees along the circumferential direction.

As described above, since the plurality of bristles <NUM> of the interdental cleaning tool <NUM> are the base end-oriented bristles, the resistance against insertion of the cleaning portion <NUM> in the interdental space can be reduced and at the same time the capability of scraping out deposit from the interdental space during the withdrawal of the cleaning portion <NUM> can be raised. Specifically, the base end-oriented bristle causes a high resistance against withdrawal from the interdental space while causing a low resistance against insertion in the interdental space, but has an increased capability of scraping out deposit during withdrawal from the interdental space, compared to a conventional bristle having a shape protruding from an outer circumferential surface of a cleaning portion body in a direction perpendicularly intersecting an axial direction of a shaft portion (hereinafter referred to as "non-tilted bristle").

Note that the embodiment disclosed above should be considered as illustrative in all aspects and not by means of limitation. The scope of the present invention is defined by the claims, not by the description on the embodiment described above, and includes all alterations within the scope of the meanings equivalent to the claims and within the scope of the claims.

For example, a plurality of bristles <NUM> may each be a type of top end-oriented bristles having a shape tilting to a top end side of the shaft portion <NUM> as advancing away from the outer circumferential surface of the cleaning portion body <NUM>. In this configuration, the resistance against withdrawal of the cleaning portion <NUM> from the interdental space can be reduced and the capability of scraping out deposit from the interdental space during insertion of the cleaning portion <NUM> can be raised. Specifically, the top end-oriented bristle causes a high resistance against insertion in the interdental space while having a high capability of scraping out the deposit during insertion in the interdental space, and causes a low resistance against withdrawal from the interdental space, compared to the non-tilted bristle.

Furthermore, a plurality of bristles <NUM> may include both the type of top end-oriented bristles and the type of base end-oriented bristles. In this case, the type of top end-oriented bristles and the type of base end-oriented bristles may alternately be arranged along the axial direction from the top end side to the base end side of the shaft portion <NUM>.

Furthermore, respective tilt angles θ of the bristles <NUM> may not be set at the same. For example, their respective tilt angles θ may be set so as to be smaller along the direction from the top end side to the base end side of the cleaning portion body <NUM>.

Each of the bristles <NUM> may have the shape of a polygonal pyramid or a plate (flat shape).

Claim 1:
An interdental cleaning tool (<NUM>) comprising:
a base portion (<NUM>) including a shaft portion (<NUM>) having a shape insertable in an interdental space; and
a cleaning portion (<NUM>) that covers at least a portion of the shaft portion (<NUM>) and is capable of cleaning an interdental space, wherein
the cleaning portion (<NUM>) includes
a cleaning portion body (<NUM>) that covers at least a portion of the shaft portion (<NUM>), and
a plurality of bristles (<NUM>) each having a shape protruding outward from an outer circumferential surface of the cleaning portion body (<NUM>),
each of the plurality of bristles (<NUM>) is a type of base end-oriented bristles having a shape tilting at an angle θ to a base end side of the shaft portion (<NUM>) as advancing away from the outer circumferential surface of the cleaning portion body (<NUM>),
the angle θ being formed between a plane perpendicularly intersecting an axial direction of the shaft portion (<NUM>) and a direction in which the each of the plurality of bristles (<NUM>) protrudes from the cleaning portion body (<NUM>), and
the cleaning portion (<NUM>) is made of a composite material containing elastomer and a reinforcing material,
wherein
the angle θ is set so as to be smaller along a direction from a top end side to a base end side of the cleaning portion body (<NUM>).