JP7619804B2 - Application brush - Google Patents

Description

The present invention relates to an application brush for applying medicine to oral tissues.

To date, toothbrushes have been proposed that have bristles attached to the head to remove plaque and other substances that have adhered to the surfaces of the teeth. Toothbrushes are generally used to scrape plaque and other substances off the surfaces of the teeth by pressing and sliding the tips of the bristles against the surfaces of the teeth (see, for example, Patent Documents 1 and 2).

JP 2006-180973 A JP 2010-253107 A

Unlike the above-mentioned removal of plaque, application brushes are used to apply medicines to oral tissues (e.g., teeth, gums, oral wall, and tongue). Specifically, this type of application brush is used, for example, to apply medicines containing fluoride to the teeth of infants and children, or to apply medicines containing moisturizing ingredients to the oral wall of elderly people. Since the main users of this type of application brush are infants, children, guardians of infants and children, elderly people, and caregivers of elderly people (collectively referred to as "infants, etc."), different performance from the above-mentioned toothbrush is required in terms of operability of the application brush in the oral cavity and safety, such as preventing the application brush from damaging oral tissues when excessive external force is applied to the application brush.

One of the objectives of the present invention is to provide an application brush that is easy to use and safe when applying medicine to oral tissues.

In order to achieve the above-mentioned object, the application brush according to the present invention is characterized by the following [1] to [3].
[1]
1. An application brush for applying a drug to oral tissue, comprising:
The applicator includes a head portion having an application protrusion, a handle portion for application operation, and a neck portion connecting the head portion and the handle portion and capable of elastic deformation,
The neck portion is
The application brush has a shaft member extending in an axial direction of the application brush, and a covering member made of a material softer than a material constituting the shaft member and covering at least a portion of the shaft member,
The shaft member is
The shaft portion has a circular cross section perpendicular to the axial direction, a protrusion protruding from the shaft portion in a direction intersecting the axial direction at a location closer to the handle portion than a center location of the shaft portion in the axial direction, and a tapered portion extending from the protrusion toward the head portion along the shaft portion and having a shape in which the area of the cross section perpendicular to the axial direction becomes smaller as the distance from the protrusion increases.
It is an application brush.
[2]
In the application brush according to the above item [1],
The shaft member is
The shaft extends continuously from the neck portion toward the handle portion, and a cross-sectional area of the shaft portion perpendicular to the axial direction is smaller than a cross-sectional area of the shaft member in the handle portion perpendicular to the axial direction.
It is an application brush.
[3]
In the application brush according to the above [1] or [2],
The shaft portion of the shaft member is
the shaft portion has an elliptical shape in a cross section perpendicular to the axial direction, the width of the shaft portion in a protruding direction in which the coating projection protrudes from the head portion being smaller than the width of the shaft portion in a direction perpendicular to the protruding direction and the axial direction;
It is an application brush.

According to the application brush having the configuration of [1] above, the neck portion connecting the head portion and the handle portion has an axial member having an axial portion with a circular cross section, and a soft covering member covering at least a part of the axial member. This allows for both a soft feel due to the soft covering member being located on the outer surface of the neck portion that may come into contact with the lips during use, and a moderate feeling of use (so-called stiffness) due to the neck portion having bending stiffness and elasticity caused by the relatively hard axial member. Furthermore, since the cross section of the axial portion is circular, the neck portion can be bent with approximately the same ease in any direction intersecting the axial direction of the application brush, compared to when the cross section has a square shape or the like. This allows the medicine to be applied to any oral tissue with approximately the same pressing force without the need to change the handle portion according to the arrangement of the oral tissue to be applied (e.g., teeth, gums, oral wall, tongue, etc.), thereby allowing the medicine to be applied uniformly to the oral tissue. In addition, regardless of where the application brush is located in the oral cavity, if excessive external force is applied to the application brush, the neck bends in a direction that releases the external force, preventing the head from damaging oral tissue.

Furthermore, the neck has a protrusion protruding from the shaft at a position closer to the handle than the center of the shaft in the axial direction. In addition, a tapered portion is provided on the head side of the protrusion, which extends from the protrusion along the shaft and has a smaller cross-sectional area (i.e., a tapered tip) as it moves away from the protrusion. This makes the stiffness of the shaft greater around the point where the protrusion is provided than the stiffness of the shaft at its center. In other words, the center of the neck is more easily bent than the base end of the neck on the handle side. Therefore, when applying a drug to tissue on the front side of the oral cavity, such as the front teeth, the center of the neck is preferentially curved in response to the operation, reducing the load on the tissue. On the other hand, when applying medication to tissues at the back of the oral cavity, such as molars, and inserting the head part between the oral cavity wall and the teeth along the dentition, the center part of the neck part is sandwiched between the oral cavity wall and the teeth, naturally preventing bending, and the base end part of the neck part has appropriate rigidity, preventing unintended bending, making it easier to insert the application brush into the back of the oral cavity.

In this way, unlike ordinary toothbrushes, the applicator brush of this configuration has a structure that allows even infants and small children to use it easily and properly. In other words, the applicator brush of this configuration is easy to use and safe when applying medicine to oral tissues.

Furthermore, as another effect, when the covering member is molded by injection molding so as to cover at least a portion of the shaft member, the provision of a tapered portion adjacent to the protrusion promotes the flow of molten resin around the protrusion, and suppresses the generation of air bubbles (voids) around the protrusion. By suppressing the generation of such air bubbles, the strength and durability of the neck can be improved. Furthermore, the molten resin is encouraged to reach the end portion of the molded object (e.g., the head portion or application protrusion) that is located on the tip side of the protrusion (i.e., downstream of the molten resin flow), and the generation of chips (short shots) at the end portion can be suppressed. By suppressing such chipping, the original application function of the application brush can be properly exerted, and the aesthetics and productivity of the application brush can be improved.

The above "circular shape" refers to a round shape including a perfect circle, an ellipse, and an oval. Furthermore, the above "material softer than the material constituting the shaft member" refers to a material having a lower hardness than the material constituting the shaft member, for example, in terms of hardness measured in a test (type A durometer) conforming to JIS K 6253 (2012). The same applies to the above "hard".

According to the application brush having the configuration of [2] above, the cross-sectional area of the shaft portion located at the neck is smaller than the cross-sectional area of the shaft member located at the handle. This makes it easier for the neck to bend than the handle. Therefore, the range of displacement of the head portion when bending (in other words, the amplitude of the head portion's swing) is smaller than when the handle portion is bent, so that the excellent operability and safety described above can be properly demonstrated even for users with small oral cavities, such as infants and small children.

According to the application brush having the configuration of [3] above, the neck is slightly less likely to bend in the direction perpendicular to the protruding direction and the axial direction (i.e., the lateral direction when the head is viewed from the front) than in the protruding direction in which the application projections protrude from the head (i.e., the depth direction when the head is viewed from the front). This appropriately suppresses lateral positional deviation of the head when the head is moved back and forth along the axial direction with the application projections of the head in contact with the teeth, gums, etc., during application of the medicine. This improves the accuracy of the application work. Furthermore, by making the neck more easily bent in the protruding direction, the load on the oral tissue during application can be further reduced.

The present invention provides an application brush that is easy to use and safe when applying medicine to oral tissues.

The present invention has been briefly described above. The details of the present invention will become clearer by reading the following description of the embodiment of the invention (hereinafter referred to as "embodiment") with reference to the attached drawings.

FIG. 1 shows an application brush according to the present invention, with FIG. 1(a) being a left side view thereof and FIG. 1(b) being a front view thereof. 2(a) is a cross-sectional view taken along line A-A in FIG. 1(b), FIG. 2(b) is an enlarged view of part B in FIG. 2(a), and FIG. 2(c) is a front view of a part corresponding to part B in FIG. 2(a). 3A is a cross-sectional view taken along line CC of FIG. 2A, and FIG. 3B is a cross-sectional view taken along line DD of FIG. 2A. FIG. 4(a) is a diagram showing how the neck of the application brush according to the present invention bends in the front-to-back direction, and FIG. 4(b) is a diagram showing how the neck of the application brush according to the present invention bends in the left-to-right direction.

<Embodiment>
Hereinafter, an application brush 1 according to an embodiment of the present invention will be described with reference to the drawings. As shown in Fig. 1, the application brush 1 has an overall rod-like shape, and is used, for example, when applying a fluoride-containing medicine (such as a gel-like medicine) to the teeth of infants and children, or when applying a medicine containing a moisturizing component to the inner walls of the oral cavity of elderly people.

For ease of explanation, unless otherwise specified, "left," "right," "front," and "rear" are defined as follows. When describing the "left-right direction" or "left-right," "left" refers to the "left" when the application brush 1 is viewed from the front. Similarly, when describing the "left-right direction" or "left-right," "right" refers to the "right" when the application brush 1 is viewed from the front. Note that "front view" refers to the case where the application brush 1 is viewed as in FIG. 1(b). Furthermore, the "front-rear direction" refers to the direction toward the "front" and "rear" when the application brush 1 is viewed from the front, "front" refers to the "front side" when the application brush is viewed from the front, and "rear" refers to the "rear side" when the application brush is viewed from the front.

As shown in FIG. 1, the application brush 1 comprises a head portion 20 having a plurality of application projections 10, an elastically deformable neck portion 30, and a handle portion 50. As shown in FIG. 2(a), each of the head portion 20, neck portion 30, and handle portion 50 comprises an axial member 60 and a covering member 80 made of a material softer than the material constituting the axial member 60 and covering the axial portion 62 and tapered portion 66a (details will be described later) of the axial member 60. The axial member 60 and covering member 80 extend continuously over the entire axial direction of the application brush 1 from the head portion 20 to the handle portion 50.

By covering the shaft 62 of the neck 30 with a soft covering member 82, the user can be provided with a soft feel due to the soft covering member 82 being located on the outer surface of the neck 30 that may come into contact with the lips during use, and a moderate feel (so-called firmness) due to the relatively hard shaft member 60 inside.

The head unit 20 has a plate-like member 20a having a front surface 21 and a back surface 22, and has multiple application protrusions 10 on both the front surface 21 and the back surface 22. When applying a medicine, the medicine (e.g., a gel-like medicine or a liquid medicine) is applied to the application protrusions 10 of the head unit 20, and the medicine is applied to the teeth, gums, etc. Depending on the position of the oral tissue to which the medicine is to be applied, it is also possible to select whether to apply the medicine to the application protrusions 11 on the front surface 21 of the head unit 20 or to the application protrusions 12 on the back surface 22 of the head unit 20.

The neck portion 30 is provided between the head portion 20 and the handle portion 50. The neck portion 30 is elastically deformable in the front-to-back direction (see FIG. 4(a)), the left-to-right direction (see FIG. 4(b)), and any diagonal direction (not shown) between the front-to-back direction and the left-to-right direction. As a result, when an infant or small child uses the application brush 1, even if an unintended external force is applied to the handle portion 50 of the application brush 1 due to a fall or collision, the neck portion 30 elastically bends in a direction that releases the external force, thereby preventing the tip of the head portion 20 from damaging oral tissue.

The handle portion 50 has a first convex portion 41 provided at the connection between the neck portion 30 and the handle portion 50, a second convex portion 42 provided at the end portion 51 of the handle portion 50 opposite the head portion 20, and a third convex portion 43 provided between the first convex portion 41 and the second convex portion 42. Providing the first to third convex portions 41, 42, and 43 on the handle portion 50 makes it easier for the user to grip the handle portion 50 and prevents the hand from slipping during use. Specifically, the first protrusion 41 is provided at the connection between the neck 30 and the handle 50, the second protrusion 42 is provided at the end 51 of the handle 50 opposite the head 20, and the third protrusion 43 is provided between the first protrusion 41 and the second protrusion 42. This allows the user's fingers to rest on at least one of the first to third protrusions 41 to 43 regardless of how the handle 50 is gripped or the size of the user's hand. Therefore, the application brush 1 can be used easily and properly whether it is used by infants, children, or the elderly themselves, or by guardians of infants and children or caregivers of the elderly.

The multiple application protrusions 11 provided on the front surface 21 of the head unit 20 each have a different longitudinal length (i.e., the tip height from the front surface 21 or back surface 22 of the head unit 20). This allows the front surface 21 of the head unit 20 to be used as a surface suitable for applying medicine to narrow areas such as between teeth, the cervical area, and back teeth. On the other hand, the multiple application protrusions 12 provided on the back surface 22 of the head unit 20 have approximately the same longitudinal length. This allows the back surface 22 of the head unit 20 to be used as a surface suitable for applying medicine to wide areas such as the surfaces of teeth, gums, tongue, and oral mucosa.

More specifically, the length of the coating protrusions 11 provided at the end of the front surface 21 opposite the neck 30 and the end of the front surface 21 on the neck 30 side is longer than the length of the coating protrusions 11 provided in the center of the front surface 21. In contrast, the length of the coating protrusions 11 may be determined so that the coating protrusions 11 become longer as they approach the end of the front surface 21 opposite the neck 30, or the length of the coating protrusions 11 may be determined so that the coating protrusions 11 become longer as they approach the end of the front surface 21 on the neck 30 side. Furthermore, the length of each coating protrusion 11 may be determined so that the coating surface formed by arranging the tips of multiple coating protrusions 11 has a shape with a peak protruding in a direction away from the front surface 21 and a valley recessed in a direction toward the front surface 21 (a so-called mountain-cut shape).

Furthermore, the cross section perpendicular to the protruding direction of the coating protrusions 11 preferably has a circular shape with a diameter of 0.5 to 1.5 mm, and more preferably has a circular shape with a diameter of 0.8 to 1.0 mm. In addition, the number of coating protrusions 11 is preferably 50 to 120, and more preferably 70 to 100.

The multiple coating protrusions 11 provided on the front surface 21 of the head unit 20 protrude in a direction perpendicular to the front surface 21. In contrast, these multiple coating protrusions 11 may protrude in a direction tilted at any angle from the direction perpendicular to the front surface 21 of the head unit 20. Similarly, the multiple coating protrusions 12 provided on the back surface 22 of the head unit 20 protrude in a direction perpendicular to the back surface 22 of the head unit 20. In contrast, these multiple coating protrusions 12 may protrude in a direction tilted at any angle from the direction perpendicular to the back surface 22 of the head unit 20.

The multiple coating protrusions 11 provided on the front surface 21 of the head unit 20 are regularly spaced apart at a predetermined interval as shown in FIG. 2(a). However, these multiple coating protrusions 11 may be irregularly arranged at any position on the front surface 21. Similarly, the multiple coating protrusions 12 provided on the back surface 22 of the head unit 20 are regularly spaced apart at a predetermined interval. However, these multiple coating protrusions 12 may be irregularly arranged at any position on the front surface 21.

As shown in Figures 1 and 2(a), multiple coating protrusions 11 are provided on almost the entire surface of the front surface 21 of the head unit 20. In contrast, the coating protrusions 11 may be provided only on a portion of the front surface 21 of the head unit 20. For example, multiple coating protrusions 11 may be provided only on the outer periphery of the front surface 21 of the head unit 20, and no coating protrusions 11 may be provided in the center of the front surface 21. Furthermore, the coating protrusions 11 may be provided around the entire outer periphery of the front surface 21, or the coating protrusions 11 may be provided only on a portion of the outer periphery of the front surface 21.

Similarly, as shown in Fig. 1 and Fig. 2(a), multiple coating protrusions 12 are provided on almost the entire surface of the back surface 22 of the head unit 20. In contrast, the coating protrusions 12 may be provided only on a portion of the back surface 22 of the head unit 20. For example, multiple coating protrusions 12 may be provided only on the outer periphery of the back surface 22 of the head unit 20, and no coating protrusions 12 may be provided in the center of the back surface 22. Furthermore, the coating protrusions 12 may be provided around the entire outer periphery of the back surface 22, or only on a portion of the outer periphery of the back surface 22. Furthermore, the coating protrusions 12 may be provided on almost the entire surface of the head unit 20, including the side of the plate-shaped member 20a between the front surface 21 and the back surface 22 of the head unit 20 and the tip of the plate-shaped member 20a.

Furthermore, the proportion of the coating protrusions 11 in the plate-shaped member 20a (i.e., the total cross-sectional area of the coating protrusions 11/the area of the front surface 21 or back surface 22 of the plate-shaped member 20a) is preferably 15-40%, and more preferably 25-35%. Note that the areas of the front surface 21 and back surface 22 of the plate-shaped member 20a also include the areas of the exposed portions of the central protrusions 68 of each.

The coating protrusions 11 provided on the front surface 21 of the head portion 20 and the coating protrusions 12 provided on the back surface 22 of the head portion 20 are made of an elastic material. The coating protrusions 11, 12 are preferably made of a low-resilience elastic material, and more preferably made of a soft elastic material or a soft low-resilience elastic material. Specifically, the coating protrusions 11, 12 are preferably made of an elastic material having a rubber hardness of 30 degrees or more and 60 degrees or less. The brush hardness of the aggregate of the multiple coating protrusions 11 provided on the front surface 21 of the head portion 20 is preferably 30 N/cm ² or less, and more preferably about 10 to 15 N/cm ^2. The brush hardness of the aggregate of the multiple coating protrusions 12 provided on the back surface 22 of the head portion 20 is also preferably 30 N/cm ² or less, and more preferably about 10 to 15 N/cm ² . The brush hardness values mentioned above are values measured by a measurement method using a compression tester in accordance with JIS S 3016 (1995).

As shown in Figures 2(a) and 2(b), the head 20, neck 30, and handle 50 of the application brush 1 have an internal shaft member 60 made of hard resin. The shaft member 60 is composed of the shaft member 61 (including the protrusion 68) of the head 20, the shaft member of the neck 30 (i.e., the shaft 62, the protrusions 66, 67, and the tapered portion 66a), and the shaft member 63 of the handle 50. The shaft member 61 of the head 20, the shaft member of the neck 30 (i.e., the shaft 62, the protrusions 66, 67, and the tapered portion 66a), and the shaft member 63 of the handle 50 are integrally formed using hard resin. That is, the shaft member 60 is provided from the tip to the rear end of the application brush 1. In other words, the shaft member 60 is disposed from the tip of the head portion 20 to the rear end of the handle portion 50 on the opposite side to the tip of the head portion 20.

It is preferable to use polypropylene as the hard resin that constitutes the shaft member 60. Polystyrene, polyethylene terephthalate, acrylonitrile butadiene styrene, polycarbonate, polyacetal, etc. may also be used as the hard resin that constitutes the shaft member 60.

The hard resin constituting the shaft member 60 preferably has a flexural modulus of 1000 MPa to 2500 MPa. For example, polypropylene with a flexural modulus of 1000 MPa to 2500 MPa can be used as the hard resin. It is preferable to use polypropylene with a flexural modulus of 1050 MPa to 2050 MPa as the hard resin, and it is even more preferable to use polypropylene with a flexural modulus of 1200 MPa to 1700 MPa.

When the hardness of the coating projections 11, 12 of the head portion 20 is A (N/ ^cm2 ) and the flexural modulus of the hard resin is B (MPa), the value of A/B is preferably 0.0003 to 0.03, more preferably 0.007 to 0.025, and even more preferably 0.01 to 0.02.

As shown in Figures 1 and 2(a), the shaft member 61 of the head unit 20 has a flat plate shape that is approximately rectangular or approximately elliptical when viewed from the front-to-rear direction, corresponding to the plate-shaped member 20a. In contrast, the shaft member 61 of the head unit 20 may be a plate shape of any polygonal or circular shape. Furthermore, the shape of the shaft member 61 of the head unit 20 is not limited to a plate shape, and may be any shape that includes at least a flat surface in at least a portion.

As shown in Figures 2(a) and 3(a), the shaft 62 located on the neck 30 has a generally cylindrical shape extending in the axial direction of the application brush 1. More specifically, as shown in Figure 3(a), the cross section of the shaft 62 (a cross section perpendicular to the axial direction of the application brush 1) has an elliptical shape with a width H1 in the front-to-rear direction (the direction in which the application projections 10 protrude from the head 20) that is slightly smaller than the width H2 in the left-to-right direction. The neck 30 and the shaft 62 may have a curved shape or a straight line shape.

By having the shaft 62 in a circular (elliptical) shape, the neck 30 can be bent with approximately equal ease in any direction perpendicular to the axial direction of the application brush 1, compared to when the cross section is square. Furthermore, the neck 30 is less likely to twist. This allows the drug to be applied to any oral tissue with approximately the same pressing force without the need to change the grip of the handle 50 according to the position of the oral tissue to be applied, thereby allowing the drug to be applied uniformly to the oral tissue. Furthermore, regardless of the position of the application brush 1 in the oral cavity, if excessive external force is applied to the application brush 1, the neck 30 can bend in a direction that releases the external force. Therefore, even infants and small children can use the application brush 1 easily and appropriately.

Furthermore, because the cross section of the shaft 62 has an elliptical shape as shown in FIG. 3(a), the neck 30 is slightly less likely to bend in the left-right direction than in the front-back direction (the direction in which the applicator protrusions 10 protrude from the head 20). As a result, when applying a drug, the head 20 is less likely to shift in position left-right when the head 20 is moved back and forth along the axial direction with the applicator protrusions 10 of the head 20 in contact with the teeth, gums, etc., thereby improving the accuracy of the application work. Furthermore, because the neck 30 is more likely to bend in the protruding direction, the load on the oral tissue during application can be further reduced.

As shown in Figures 1 and 2(a), the shaft member 63 of the handle portion 50 has a first shaft body protrusion 71 provided at the connection between the shaft member of the neck portion 30 (particularly the shaft portion 62 and the protrusion portion 66) and the shaft member 63 of the handle portion 50, similar to the external shape of the handle portion 50, a second shaft body protrusion 72 provided at the end portion 64 of the shaft member 63 of the handle portion 50 on the opposite side to the shaft member 61 of the head portion 20, and a third shaft body protrusion 73 provided between the first shaft body protrusion 71 and the second shaft body protrusion 72.

As shown in FIG. 3B, the cross section of the shaft member 63 of the handle portion 50 (cross section perpendicular to the axial direction of the application brush 1) has a perfect circle shape near the neck portion 30. The cross section of the handle portion 50 at the second shaft body protrusion 72 and the third shaft body protrusion 73 away from the neck portion 30 is not limited to a perfect circle shape, and may have an elliptical shape, a polygonal shape, a polygonal shape with rounded corners, etc. As can be understood from a comparison of FIG. 3A and FIG. 3B, the cross-sectional area of the shaft portion 62 is smaller than the cross-sectional area of the shaft member 63 of the handle portion 50. This makes it easier for the neck portion 30 to bend than the handle portion 50. Therefore, the range of displacement of the head portion 20 when bending (in other words, the swing range of the head portion 20) is smaller than when the handle portion 50 is bent, so that the above-mentioned excellent operability and safety can be properly demonstrated even for users whose oral cavity itself is small, such as infants and children. Furthermore, the cross-sectional area of the connection between the shaft member of the neck portion 30 (particularly the shaft portion 62 and the protrusion portion 66) and the shaft member 63 of the handle portion 50 gradually increases (i.e., expands in diameter) toward the handle portion 50.

The first shaft body protrusion 71 and the third shaft body protrusion 73 of the shaft member 63 of the handle part 50 have a substantially ellipsoid shape. Specifically, the first shaft body protrusion 71 provided at the connection part between the shaft member of the neck part 30 (particularly the shaft part 62 and the protrusion part 66) and the shaft member 63 of the handle part 50 has a convex shape that protrudes in a direction substantially perpendicular to the longitudinal direction of the shaft member 63 of the handle part 50 when viewed from any direction perpendicular to the axial direction of the application brush 1. Similarly, the third shaft body protrusion 73 provided between the first shaft body protrusion 71 and the second shaft body protrusion 72 also has a convex shape that protrudes in a direction substantially perpendicular to the longitudinal direction of the shaft member 63 of the handle part 50 when viewed from any direction perpendicular to the axial direction of the application brush 1.

On the other hand, the second shaft protrusion 72 provided at the end 64 of the shaft member 63 of the handle portion 50 does not have a convex shape that protrudes in a direction approximately perpendicular to the longitudinal direction of the shaft member 63 of the handle portion 50 when viewed from the left-right direction, and has a convex shape that protrudes in a direction approximately perpendicular to the longitudinal direction of the shaft member 63 of the handle portion 50 when viewed from the front-back direction.

In correspondence with the first shaft body protrusion 71 and the third shaft body protrusion 73 of the shaft member 63 of the handle portion 50 having a substantially ellipsoidal shape, the first protrusion 41 and the third protrusion 43 of the handle portion 50 also have a substantially ellipsoidal shape, as shown in Figures 1 and 2(a).

That is, the first convex portion 41 provided at the connection between the neck portion 30 and the handle portion 50 has a convex shape that protrudes in a direction approximately perpendicular to the longitudinal direction of the handle portion 50 when viewed from any direction perpendicular to the axial direction of the application brush 1. Similarly, the third convex portion 43 provided between the first convex portion 41 and the second convex portion 42 also has a convex shape that protrudes in a direction approximately perpendicular to the longitudinal direction of the handle portion 50 when viewed from any direction perpendicular to the axial direction of the application brush 1.

On the other hand, the second protrusion 42 provided on the end 51 of the handle portion 50 does not have a protruding shape that protrudes in a direction that is approximately perpendicular to the longitudinal direction of the handle portion 50 when viewed from the left-right direction, and has a protruding shape that protrudes in a direction that is approximately perpendicular to the longitudinal direction of the handle portion 50 when viewed from the front-back direction.

As shown in FIG. 1, the second shaft protrusion 72 provided at the end 64 of the shaft member 63 of the handle portion 50 has an insertion hole 65. The second protrusion 42 provided at the end 51 of the handle portion 50 has an insertion hole 52. The insertion hole 52 of the second protrusion 42 corresponds to the insertion hole 65 of the second shaft protrusion 72, and a hook or string for storing the application brush 1 can be passed through these insertion holes 52, 65.

As shown in FIG. 2(a), the shaft 62 is provided with a protrusion 66 that protrudes in both the front and rear directions at a location closer to the handle 50 than the central location P in the axial direction of the shaft 62, and a protrusion 67 that protrudes in both the front and rear directions at a location closer to the head 20 than the central location P in the axial direction of the shaft 62. The shaft member 61 of the head 20 is provided with a protrusion 68 that protrudes in both the front and rear directions at approximately the central location in the axial direction of the shaft member 61.

In particular, as shown in Figs. 2(b) and 2(c), on the head 20 side of the protrusion 66, there is provided a tapered section 66a that extends from the protrusion 66 toward the head 20 along the axial direction of the shaft 62 and tapers toward the head 20 (the cross-sectional area becomes smaller). The tapered section 66a is continuous with the shaft 62 (cylindrical section) at a location adjacent to the head 20 side of the protrusion 66. The tip end 66b of the tapered section 66a is located between the protrusion 66 and the central location P. Note that no similar tapered section is provided on the base end side of the protrusion 67 (the side closer to the handle 50).

By providing the tapered portion 66a in this way, the rigidity of the shaft portion 62 around the portion where the protrusion 66 is provided is greater than the rigidity of the shaft portion 62 at the central portion P of the shaft portion 62. In other words, the central portion P of the neck portion 30 is easier to bend than the portion closer to the handle portion 50 than the central portion P. Therefore, when the head portion 20 bends in the front-rear direction (see FIG. 4(a)), and when the head portion 20 bends in the left-right direction (see FIG. 4(b)), the neck portion 30 will bend preferentially around the central portion P. Furthermore, since a similar tapered portion is not provided on the base end side of the protrusion 67, the rigidity of the portion where the protrusion 67 is provided is not as large as the rigidity of the portion where the protrusion 66 having the tapered portion 66a is provided. Therefore, the effect of the presence of the protrusion 67 on the ease of bending of the neck portion 30 can be reduced.

Therefore, when applying a medicine to tissues on the front side of the oral cavity, such as the front teeth, the central part P of the neck part 30 bends appropriately to reduce the load on the tissue. By bending the central part P of the neck part 30, the range of displacement of the head part 20 (in other words, the amplitude) can be made smaller than when the base end part of the neck part 30 bends. Since the range of displacement of the head part 20 is small, the application brush 1 can be used suitably for infants and children with small mouths. On the other hand, when applying a medicine to tissues on the back side of the oral cavity, such as molars, when the head part 20 is inserted between the oral cavity wall and the teeth along the dentition, the central part P of the neck part 30 is sandwiched between the oral cavity wall and the teeth to naturally suppress bending, and the base end part of the neck part 30 has appropriate rigidity to suppress unintended bending, making it easier to insert the application brush 1 into the back side of the oral cavity. Furthermore, when the covering member 80 is molded by injection molding to cover the shaft member 60, the tapered portion 66a is provided adjacent to the protrusion 66, which promotes the flow of molten resin around the protrusion 66 and suppresses the generation of air bubbles (voids) around the protrusion 66. By suppressing the generation of such air bubbles, the strength and durability of the neck portion 30 can be improved. In addition, the molten resin is encouraged to reach the end portions of the head portion 20 and the application protrusions 11 and 12, which are located on the tip side (i.e., downstream of the molten resin flow) of the protrusion 66, and the generation of chips (short shots) at the end portions can be suppressed. By suppressing such chipping, the original application function of the application brush 1 can be properly exerted, and the aesthetics and productivity of the application brush 1 can be improved.

In addition, the protrusions 66, 67, and 68 also have the function of maintaining the position of the shaft member 60 within the mold for molding the covering member 80 when the covering member 80 is molded to cover the shaft member 60.

As shown in FIG. 2(a) etc., the covering member 80 is composed of a covering member 81 for the head portion 20, a covering member 82 for the neck portion 30, and a covering member 83 for the handle portion 50. However, the top surfaces of the protrusions 66, 67 provided on the shaft portion 62 located on the neck portion 30, and the top surface of the protrusion 68 provided on the shaft member 61 of the head portion 20 are exposed and not covered by the covering member 80.

The covering member 80 is made of a material softer than the material constituting the shaft member 60 and covers the outer periphery of the shaft member 60 except for some exposed areas (i.e., the top surfaces of the protrusions 66, 67, 68 and the inner surface of the insertion hole 52). Here, "a material softer than the material constituting the shaft member 60" refers to a material that has a lower hardness than the material constituting the shaft member 60, for example, in terms of hardness measured in a test (type A durometer) conforming to JIS K 6253 (2012).

It is preferable that a low-resilience elastic material is used as the material constituting the covering member 80. Specifically, it is preferable that a silicone rubber or a thermoplastic elastomer is used as the elastic material constituting the covering member 80. Examples of the thermoplastic elastomer include polyolefin-based, styrene-based, polyester-based, and polyurethane-based thermoplastic elastomers.

The multiple coating protrusions 10 of the head unit 20 and the covering member 81 of the head unit 20 are integrally formed from the same elastic material. That is, the coating protrusions 11 on the front surface 21 of the head unit 20, the coating protrusions 12 on the back surface 22 of the head unit 20, and the covering member 81 of the head unit 20 are integrally formed from the same elastic material.

Thus, unlike ordinary toothbrushes, the coating protrusions 11 on the front surface 21 of the head part 20 are not planted on the front surface 21. Similarly, the coating protrusions 12 on the back surface 22 of the head part 20 are not planted on the back surface 22. The coating protrusions 11, 12 protrude from the front surface 21 or back surface 22 of the head part 20 and are integrated with the front surface 21 or back surface 22 of the head part 20. Therefore, unlike the bristles of ordinary toothbrushes, the medicine does not soak into the spaces between the fine bristles that make up the bristles or into the planted parts of the bristles, so the coating protrusions 11, 12 can hold the medicine at the center of the tip parts of the coating protrusions 11, 12, and the medicine can be applied without waste. Furthermore, the coating protrusions 11, 12 are easy to clean and are excellent in terms of hygiene. In addition, the coating protrusions 11, 12 are also excellent in durability because they are less likely to deteriorate, such as the bristles spreading out, as in ordinary toothbrushes.

<Action and Effects>
The main functions and effects of the application brush 1 described above will be summarized again below.
According to the application brush 1, the neck portion 30 connecting the head portion 20 and the handle portion 50 has an axis member 60 having an axis portion 62 having a circular cross section, and a soft covering member 82 covering the axis portion 62 and the like. This allows for both a soft feel due to the soft covering member 82 being located on the outer surface of the neck portion 30 that may come into contact with the lips during use, and a moderate feeling of use such as stiffness due to the bending hardness and elasticity caused by the relatively hard axis member 60. Furthermore, since the cross section of the axis portion 62 is circular, the neck portion 30 can be bent with approximately the same ease in any direction perpendicular to the axial direction of the application brush 1, compared to when the cross section has a square shape or the like. This allows the drug to be applied to any oral tissue with approximately the same pressing force without the need to change the grip of the handle portion 50 according to the arrangement of the oral tissue to be applied, thereby allowing the drug to be applied uniformly to the oral tissue. In addition, regardless of the position of the application brush 1 in the oral cavity, if excessive external force is applied to the application brush 1, the neck portion 30 bends in a direction to release the external force, thereby preventing the head portion 20 from damaging oral tissue, etc.

Furthermore, the neck 30 has a protrusion 66 protruding from the shaft 62 at a position closer to the handle 50 than the central point P of the shaft 62 in the axial direction. In addition, a tapered portion 66a is provided on the head 20 side of the protrusion 66, which extends from the protrusion 66 along the shaft 62 and tapers toward the head 20. This makes the rigidity of the shaft 62 greater around the point where the protrusion 66 is provided than the rigidity of the shaft 62 at the central point P. In other words, the central point P of the neck 30 is more easily bent than the base end portion on the handle 50 side of the neck 30. Therefore, when applying a drug to tissue on the front side of the oral cavity, such as the front teeth, the central point P of the neck 30 is preferentially curved in response to the operation, thereby reducing the load on the tissue. On the other hand, when applying a medicine to tissues at the back of the oral cavity, such as molars, and inserting the head portion 20 between the oral cavity wall and the teeth along the dentition, the center point P of the neck portion 30 is sandwiched between the oral cavity wall and the teeth, naturally suppressing bending, and the base end portion of the neck portion 30 has an appropriate strength, suppressing unintended bending, making it easier to insert the application brush 1 into the back of the oral cavity.

In this way, unlike ordinary toothbrushes, the application brush 1 has a structure that allows even infants and small children to use it easily and properly. In other words, the application brush 1 is easy to use and safe when applying medicine to oral tissues.

Furthermore, with the application brush 1, the cross-sectional area of the shaft 62 located at the neck 30 is smaller than the cross-sectional area of the shaft member 63 inside the handle 50. This makes it easier for the neck 30 to bend than the handle 50. Therefore, the range of displacement of the head 20 when bending (in other words, the amplitude of the head 20's swing) is smaller than when the handle 50 is bent, so the excellent operability and safety described above can be properly demonstrated even for users with small oral cavities, such as infants and children.

Furthermore, with the application brush 1, the neck 30 is slightly less likely to bend in the left-right direction (i.e., the horizontal direction when the head 20 is viewed from the front) than in the front-rear direction (i.e., the depth direction when the head 20 is viewed from the front). This appropriately suppresses misalignment of the head 20 in the left-right direction when the head 20 is moved back and forth along the axial direction with the application projections 10 of the head 20 in contact with the teeth, gums, etc., during application of the medicine. This improves the accuracy of the application work. Furthermore, by making the neck 30 more likely to bend in the protruding direction, the load on the oral tissue during application can be further reduced.

In addition, with the application brush 1, the application protrusions 11 and 12 protrude from the plate-like member 20a of the head portion 20 toward one side and the other side in the thickness direction, respectively. This makes it possible to easily apply the medicine to any oral tissue without the need to change the grip of the handle portion 50 according to the position of the oral tissue to be applied.

<Other forms>
The present invention is not limited to the above-described embodiments, and various modifications can be adopted within the scope of the present invention. For example, the present invention is not limited to the above-described embodiments, and appropriate modifications, improvements, etc. are possible. In addition, the material, shape, size, number, arrangement location, etc. of each component in the above-described embodiments are arbitrary as long as the present invention can be achieved, and are not limited.

For example, in the above embodiment, each of the head portion 20, neck portion 30, and handle portion 50 constituting the application brush 1 is composed of an axis member 60 and a covering member 80 that covers the outer periphery of the axis member 60. In contrast, as long as only the neck portion 30 is composed of an axis member 60 and a covering member 80 that covers the outer periphery of the axis member 60, at least one of the head portion 20 and the handle portion 50 may be composed of only the axis member 60.

Furthermore, in the above embodiment, the shaft portion 62 located at the neck portion 30 has a cross-sectional shape that is elliptical and elongated in the horizontal direction. In contrast, the shaft portion 62 may have a cross-sectional shape that is a perfect circle.

In addition, in the above embodiment, the head portion 20 has a coating protrusion 10 that protrudes toward both one side and the other side in the thickness direction of the plate-like member 20a. In contrast, the head portion 20 may have a coating protrusion 10 that protrudes toward only one side or the other side in the thickness direction of the plate-like member 20a.

In addition, in the above embodiment, the multiple application protrusions 10 of the head unit 20 and the covering member 81 of the head unit 20 are integrally formed from the same elastic material. In contrast, the application protrusions 10 and the covering member 81 may be formed from different types of elastic materials, or may be formed by preparing each separately and then assembling them together.

Here, the features of the embodiment of the application brush 1 according to the present invention described above will be briefly summarized and listed below in [1] to [3].
[1]
An application brush (1) for applying a drug to oral tissue, comprising:
The applicator comprises a head portion (20) having an application projection (10), a handle portion (50) for an application operation, and a neck portion (30) that connects the head portion (20) and the handle portion (50) and is elastically deformable,
The neck portion (30) is
The application brush has an axial member (60) extending in the axial direction of the application brush, and a covering member (80) made of a material softer than the material constituting the axial member (60) and covering at least a portion of the axial member (60),
The shaft member (60) is
the shaft portion (62) having a circular cross section perpendicular to the axial direction, a protrusion (66) protruding from the shaft portion (62) in a direction intersecting the axial direction at a location closer to the handle portion (50) than a central location (P) of the shaft portion (62) in the axial direction, and a tapered portion (66a) extending from the protrusion (66) toward the head portion (20) along the shaft portion (62) and having a shape in which the area of the cross section perpendicular to the axial direction becomes smaller with increasing distance from the protrusion (66),
Application brush (1).
[2]
In the application brush (1) described in the above [1],
The shaft member (60) is
The shaft portion (62) extends continuously from the neck portion (30) toward the handle portion (50), and a cross-sectional area of the shaft portion (62) perpendicular to the axial direction is smaller than a cross-sectional area of the shaft member (60) in the handle portion (50) perpendicular to the axial direction.
Application brush (1).
[3]
In the application brush (1) according to the above [1] or [2],
The shaft portion (62) of the shaft member (60) is
the shaft portion (62) has an elliptical shape in a cross section perpendicular to the axial direction, the width (H1) of the shaft portion (62) in a protruding direction in which the coating projection (10) protrudes from the head portion (20) being smaller than a width (H2) of the shaft portion (62) in a direction perpendicular to the protruding direction and the axial direction;
Application brush (1).

REFERENCE SIGNS LIST 1 Application brush 10 Application protrusion 11 Application protrusion 12 Application protrusion 20 Head portion 20a Plate-shaped member 30 Neck portion 50 Handle portion 60 Shaft member 62 Shaft portion 66 Protrusion portion 66a Tapered portion 80 Covering member P Central portion

Claims (3)

1. An application brush for applying a drug to oral tissue, comprising:
The applicator includes a head portion having an application protrusion, a handle portion for application operation, and a neck portion connecting the head portion and the handle portion and capable of elastic deformation,
The neck portion is
The application brush has a shaft member extending in an axial direction of the application brush, and a covering member made of a material softer than a material constituting the shaft member and covering at least a portion of the shaft member,
The shaft member is
The shaft portion has a circular cross section perpendicular to the axial direction, a protrusion protruding from the shaft portion in a direction intersecting the axial direction at a location closer to the handle portion than a center location of the shaft portion in the axial direction, and a tapered portion extending from the protrusion toward the head portion along the shaft portion and having a shape in which the area of the cross section perpendicular to the axial direction becomes smaller as the distance from the protrusion increases.
Application brush. 2. The application brush according to claim 1,
The shaft member is
The shaft extends continuously from the neck portion toward the handle portion, and a cross-sectional area of the shaft portion perpendicular to the axial direction is smaller than a cross-sectional area of the shaft member in the handle portion perpendicular to the axial direction.
Application brush. The application brush according to claim 1 or 2,
The shaft portion of the shaft member is
the shaft portion has an elliptical shape in a cross section perpendicular to the axial direction, the width of the shaft portion in a protruding direction in which the coating projection protrudes from the head portion being smaller than the width of the shaft portion in a direction perpendicular to the protruding direction and the axial direction;
Application brush.

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