EP3903632A1 - Brosse à dents - Google Patents

Brosse à dents Download PDF

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Publication number
EP3903632A1
EP3903632A1 EP19905494.1A EP19905494A EP3903632A1 EP 3903632 A1 EP3903632 A1 EP 3903632A1 EP 19905494 A EP19905494 A EP 19905494A EP 3903632 A1 EP3903632 A1 EP 3903632A1
Authority
EP
European Patent Office
Prior art keywords
displacement amount
reversal
threshold value
repulsive force
surface side
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP19905494.1A
Other languages
German (de)
English (en)
Other versions
EP3903632A4 (fr
Inventor
Reona NODA
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Lion Corp
Original Assignee
Lion Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Lion Corp filed Critical Lion Corp
Publication of EP3903632A1 publication Critical patent/EP3903632A1/fr
Publication of EP3903632A4 publication Critical patent/EP3903632A4/fr
Pending legal-status Critical Current

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Classifications

    • A—HUMAN NECESSITIES
    • A46—BRUSHWARE
    • A46B—BRUSHES
    • A46B5/00—Brush bodies; Handles integral with brushware
    • A46B5/002—Brush bodies; Handles integral with brushware having articulations, joints or flexible portions
    • A46B5/0054—Brush bodies; Handles integral with brushware having articulations, joints or flexible portions designed to allow relative positioning of the head to body
    • A46B5/0062—Brush bodies; Handles integral with brushware having articulations, joints or flexible portions designed to allow relative positioning of the head to body being flexible or resilient during use
    • A46B5/0066—Flexible resilience by elastic deformation of the material
    • A—HUMAN NECESSITIES
    • A46—BRUSHWARE
    • A46B—BRUSHES
    • A46B5/00—Brush bodies; Handles integral with brushware
    • A—HUMAN NECESSITIES
    • A46—BRUSHWARE
    • A46B—BRUSHES
    • A46B5/00—Brush bodies; Handles integral with brushware
    • A46B5/02—Brush bodies; Handles integral with brushware specially shaped for holding by the hand
    • A46B5/021—Grips or handles specially adapted to conform to the hand
    • A—HUMAN NECESSITIES
    • A46—BRUSHWARE
    • A46B—BRUSHES
    • A46B7/00—Bristle carriers arranged in the brush body
    • A46B7/06—Bristle carriers arranged in the brush body movably during use, i.e. the normal brushing action causing movement
    • A—HUMAN NECESSITIES
    • A46—BRUSHWARE
    • A46B—BRUSHES
    • A46B9/00—Arrangements of the bristles in the brush body
    • A46B9/02—Position or arrangement of bristles in relation to surface of the brush body, e.g. inclined, in rows, in groups
    • A46B9/04—Arranged like in or for toothbrushes
    • A—HUMAN NECESSITIES
    • A46—BRUSHWARE
    • A46B—BRUSHES
    • A46B2200/00—Brushes characterized by their functions, uses or applications
    • A46B2200/10—For human or animal care
    • A46B2200/1066—Toothbrush for cleaning the teeth or dentures

Definitions

  • the present invention relates to a toothbrush.
  • Root caries is caries of dentin exposed due to gingival recession, and since dentin has a higher composition ratio of organic components than enamel, caries progresses faster.
  • One example of a causes of gingival recession is over-brushing, in which brushing is performed at a brushing pressure larger than that of an appropriate value.
  • reducing the brushing pressure can be achieved by at least one of reducing the load and increasing the bristle tufting area.
  • a toothbrush having a specification designed to incline a neck portion above a bristle tufting surface in advance, to bend the neck portion when brushing, and to be brushed with a force straightening the neck portion when brushing a soft toothbrush having a specification that uses bristles with a small diameter, a toothbrush having a specification in which the center of gravity of a grip portion is disposed closer to a rear end portion of a handle so that force is not easily applied to a bristle tufting portion, or the like is commercially available.
  • a toothbrush having a wide head width and the like are commercially available. Incidentally, in these specifications, although it is possible to reduce the brushing pressure, it is difficult to make all users recognize the appropriate brushing pressure at the same level and control the brushing pressure.
  • examples of means for causing a user to recognize an appropriate brushing pressure include a toothbrush disclosed in Patent Document 1.
  • the toothbrush disclosed in Patent Document 1 has a two-beam structure disposed between a head portion and a grip portion, and including a rear side beam to which compressive stress is applied and a facial side beam to which tensile stress is applied during normal use.
  • the toothbrush disclosed in Patent Document 1 can cause the user to recognize that the appropriate brushing pressure is exceeded by reversing the rear side beam.
  • the present invention has been made in consideration of the above points, and an object thereof is to provide a toothbrush that enables an appropriate brushing pressure to be recognized with high versatility and good usability.
  • a toothbrush including: a head portion provided on a tip end side in a long axis direction and having a bristle tufting surface; a grip portion disposed on a rear end side from the head portion; and a neck portion disposed between the bristle tufting surface and the grip portion; in which a sensing portion for sensing that an external force in a first direction orthogonal to the bristle tufting surface exceeds a predetermined value is provided on a rear end side from the bristle tufting surface, the sensing portion changes a relationship between a displacement amount of the head portion when a load is applied to the head portion in the first direction toward a back surface side opposite to the bristle tufting surface and a repulsive force generated according to the displacement amount from an increase to a decrease in the repulsive force at a first threshold value according to an increase in the displacement amount, and stops the decrease in the repulsive force at a second threshold value where the displacement amount
  • the repulsive force A is 1.0 N or more and 5.0 N or less.
  • a value represented by D - C is 0 mm or more and 1.5 mm or less.
  • the displacement amount C is 28 mm or less.
  • the sensing portion when the displacement amount exceeds the second threshold value, causes the repulsive force to increase according to the increase in the displacement amount.
  • a rate of increase in the repulsive force until the displacement amount of the head portion reaches 4 mm is 0.015 or more.
  • the toothbrush in the sensing portion, when a load is applied to the back surface side to stop at least the decrease in the repulsive force and thereafter the load is released, a relationship between the displacement amount and the repulsive force after the release remains the same as before the load is applied.
  • the sensing portion includes a reversal portion that connects a first region on the tip end side from the sensing portion and a second region on the rear end side from the sensing portion, and that snaps, buckles, and reverses as the head portion is displaced to the back surface side opposite to the bristle tufting surface in the first direction due to the external force exceeding the threshold value, and an elastic deformation portion that is disposed with a gap from the reversal portion, connects the first region and the second region, and elastically deforms at least up to the external force at which the reversal portion snaps, buckles, and reverses, and the reversal portion is located between an outer contour on the bristle tufting surface side and an outer contour on the back surface side in the elastic deformation portion in a side view viewed in a direction orthogonal to the long axis direction and the first direction.
  • a path where the elastic deformation portion is deformed due to the external force in the first direction and a path where the reversal portion is deformed due to the external force in the first direction are provided in a non-interfering manner.
  • the elastic deformation portion and the reversal portion are disposed with a gap in a second direction orthogonal to the first direction and the long axis direction.
  • the reversal portion has a protrusion shape toward the back surface side when the external force in the first direction is equal to or less than the predetermined value, and is reversed in the protrusion shape toward the bristle tufting surface side when the external force in the first direction exceeds the predetermined value.
  • the reversal portion includes a groove portion extending in the second direction on at least one of the bristle tufting surface side and the back surface side in a region including an apex of the protrusion shape.
  • the reversal portion is made of a hard resin
  • a portion of the elastic deformation portion is made of a resin having a hardness different from that of the hard resin.
  • the gap is a through-hole extending in the first direction.
  • the present invention can provide a toothbrush that enables an appropriate brushing pressure to be recognized with high versatility and good usability.
  • Fig. 1 is a front view of a toothbrush 1.
  • Fig. 2 is a cross-sectional view of the toothbrush 1 along a plane including a center in a width direction (vertical direction in Fig. 1 ).
  • the toothbrush 1 of the present embodiment is provided with a head portion 10 disposed on a tip end side in the long axis direction (hereinafter, simply referred to as a tip end side) and on which a bristle bundle (not illustrated) of bristles is tufted, a neck portion 20 extending on a rear end side of the head portion 10 in the long axis direction (hereinafter, simply referred to as a rear end side), a sensing portion 70 extending to a rear end side of the neck portion 20, and a grip portion 30 extending to a rear end side of the sensing portion 70 (hereinafter, the head portion 10, the neck portion 20, the grip portion 30, and the sensing portion 70 are collectively referred to as a handle body 2).
  • the toothbrush 1 of the present embodiment is a molded body in which a hard portion H made of a hard resin and a soft portion E made of a soft resin are integrally molded.
  • the hard portion H constitutes at least a portion of each of the head portion 10, the neck portion 20, the grip portion 30, and the sensing portion 70.
  • the soft portion E constitutes a portion of each of the grip portion 30 and the sensing portion 70 (details will be described later).
  • the head portion 10 includes a bristle tufting surface 11 on one side in the thickness direction (direction orthogonal to a paper surface in Fig. 1 ).
  • the bristle tufting surface 11 side in the thickness direction is defined as a front surface side in a front surface direction
  • the side opposite to the bristle tufting surface is defined as a back surface side
  • a direction orthogonal to the thickness direction and the long axis direction is defined as a width direction (or as appropriate, a side surface direction).
  • a plurality of bristle tufting holes 12 are formed on the bristle tufting surface 11.
  • a bristle bundle of bristles (not illustrated) is tufted in the bristle tufting hole 12.
  • a width of the head portion 10, that is, a length in the width direction parallel to the bristle tufting surface 11 on the front surface side and orthogonal to the long axis direction (hereinafter, simply referred to as a width), is not particularly limited, and is preferably 7 mm or more and 13 mm or less, for example.
  • a width is the above lower limit value or more, a sufficient area for tufting the bristle bundle can be secured, and when the width is the above upper limit value or less, the operability in the oral cavity is further enhanced.
  • the length of the head portion 10 in the long axis direction (hereinafter, simply referred to as a length) is not particularly limited, and is preferably 10 mm or more and 33 mm or less, for example.
  • a length of the head portion 10 is the above lower limit value or more, a sufficient area for tufting the bristle bundle can be secured, and when the length is the above upper limit value or less, the operability in the oral cavity is further enhanced.
  • a boundary between the neck portion 20 and the head portion 10 in the long axis direction in the present embodiment is a position where the width of the neck portion 20 is a minimum value from the neck portion 20 toward the head portion 10.
  • the length of the head portion 10 in the thickness direction (hereinafter, simply referred to as a thickness) can be determined in consideration of the material and the like, and is preferably 2.0 mm or more and 4.0 mm or less.
  • a thickness can be determined in consideration of the material and the like, and is preferably 2.0 mm or more and 4.0 mm or less.
  • the thickness of the head portion 10 is the above lower limit value or more, the strength of the head portion 10 is further enhanced.
  • the thickness of the head portion 10 is the above upper limit value or less, the reachability to the rear of the molars can be enhanced and the operability in the oral cavity is further enhanced.
  • the bristle bundle is a bundle of a plurality of bristles.
  • the length (bristle length) from the bristle tufting surface 11 to the tip end of the bristle bundle can be determined in consideration of a bristle waist and the like required for the bristle bundle, and is, for example, 6 to 13 mm. All the bristle bundles may have the same bristle length or may be different from each other.
  • a thickness of the bristle bundle can be determined in consideration of the bristle waist and the like required for the bristle bundle, and is set to, for example, 1 to 3 mm. All the bristle bundles may have the same bristle bundle diameter or may be different from each other.
  • Examples of the bristles constituting the bristle bundle include bristles in which diameters gradually decrease toward a tip of the bristle and have sharpened tips of the bristles (tapered bristles), and bristles in which diameters from the bristle tufting surface 11 toward a tip of the bristle are substantially the same as each other (straight bristles).
  • Examples of a straight bristle include a bristle in which a tip of the bristle is a plane substantially parallel to the bristle tufting surface 11, and a bristle in which a tip of the bristle is hemispherically rounded.
  • Examples of the material of the bristle include polyamides such as 6-12 nylon (6-12NY), 6-10 nylon (6-10NY), polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), polyolefins such as polypropylene (PP), elastomer resins such as polyolefin-based elastomers and styrene-based elastomers, and the like. These resin materials can be used alone or in a combination of two or more.
  • examples of the bristle include a polyester bristle with a multi-core structure having a core portion and at least one or more layers of sheath portions provided on the outside of the core portion.
  • the cross-sectional shape of the bristle is not particularly limited, and may be a circular shape such as a perfect circle or an ellipse, a polygonal shape, a star shape, a three-leaf clover shape, a four-leaf clover shape, or the like.
  • the cross-sectional shapes of all the bristles may be the same as each other or different from each other.
  • a plurality of bristles having different thicknesses may be used in any combination in consideration of usability, brushing feeling, cleaning effect, durability, and the like.
  • the length of the neck portion 20 is preferably 40 mm or more and 70 mm or less in terms of operability.
  • the width of the neck portion 20 is formed to gradually increase from a position where the minimum value is obtained toward the rear end side.
  • the neck portion 20 in the present embodiment is formed to gradually increase from a position where the width has a minimum value toward the rear end side.
  • the neck portion 20 is formed to gradually increase from a position where the thickness has a minimum value toward the rear end side.
  • the width and thickness of the neck portion 20 at the minimum position are preferably 3.0 mm or more and 4.5 mm or less.
  • the width and thickness of the neck portion 20 at the minimum position are the above lower limit value or more, the strength of the neck portion 20 is further enhanced.
  • the width and thickness are the above upper limit value or less, the lips are likely to be closed, the reachability to the molars is enhanced, and the operability in the oral cavity is further enhanced.
  • the width and thickness of the neck portion 20 formed to gradually increase from the position where the minimum value is obtained toward the rear end side can be appropriately determined in consideration of the material and the like.
  • the front surface side of the neck portion 20 in the side view is inclined toward the front surface side and toward the rear end side.
  • the back surface side of the neck portion 20 in the side view is inclined toward the back surface side and toward the rear end side.
  • the neck portion 20 is inclined in a direction where a distance from the center in the width direction increases toward the rear end side in a front view.
  • the boundary between the neck portion 20 and the sensing portion 70 in the present embodiment is the position of the tip end on the neck side 20 where an elastic deformation portion 90 that will be described later is provided.
  • the width is expanded from the neck portion 20 toward the grip portion 30 with an arcuate contour in both a front view and a side view, and a position of the center of curvature of the arc coincides with a changed position in the long axis direction.
  • the boundary between the neck portion 20 and the sensing portion 70 coincides with a position in the long axis direction where the center of curvature changes from the outside of the arcuate contour to the center side in the width direction in the front view illustrated in Fig. 1 .
  • the boundary between the neck portion 20 and the sensing portion 70 coincides with a position in the long axis direction where the center of curvature changes from the outside of the arcuate contour to the center side in the thickness direction in a side view illustrated in Fig. 2 .
  • the grip portion 30 is disposed in the long axis direction. As illustrated in Fig. 1 , a length of the grip portion 30 in the width direction gradually narrows from the boundary with the sensing portion 70 toward the rear end side, and then extends at a substantially constant length. As illustrated in Fig. 2 , a length of the grip portion 30 in the thickness direction gradually narrows from the boundary with the sensing portion 70 toward the rear end side, and then extends at a substantially constant length.
  • the boundary between the sensing portion 70 and the grip portion 30 in the present embodiment is the position of the tip end on the grip portion side 30 where the elastic deformation portion 90 that will be described later is provided.
  • the width is reduced from the sensing portion 70 toward the grip portion side 30 with an arcuate contour in both a front view and a side view, and a position of the center of curvature of the arc coincides with a changed position in the long axis direction.
  • the boundary between the sensing portion 70 and the grip portion 30 coincides with a position in the long axis direction where the center of curvature changes from the center side in the width direction to the outside of the arcuate contour in the front view illustrated in Fig. 1 .
  • the boundary between the sensing portion 70 and the grip portion 30 coincides with a position in the long axis direction where the center of curvature changes from the center side in the thickness direction to the outside of the arcuate contour in the side view illustrated in Fig. 2 .
  • the position in the long axis direction where the length of the grip portion 30 in the width direction gradually narrows from the boundary with the sensing portion 70 toward the rear end side and then is a substantially constant length, and the position in the long axis direction where the length of the grip portion 30 in the thickness direction gradually narrows from the boundary with the sensing portion 70 toward the rear end side and then is a substantially constant length are the same as each other.
  • the grip portion 30 includes a soft portion 31E at the center in the width direction on the front surface side.
  • the soft portion 31E constitutes a portion of the soft portion E.
  • the soft portion 31E gradually narrows from the boundary with the sensing portion 70 toward the rear end side in the front view, and then extends at a substantially constant length.
  • a side edge of the soft portion 31E and a side edge of the grip portion 30 on the outside in the width direction are formed at a substantially constant distance in the front view.
  • the grip portion 30 includes a hard portion 30H.
  • the hard portion 30H constitutes a portion of the hard portion H.
  • the hard portion 30H includes a hollow 31H in which a portion of the soft portion 31E is embedded on the front surface side.
  • the hollow 31H gradually narrows from the boundary with the sensing portion 70 toward the rear end side in the front view, and then extends at a substantially constant length.
  • a portion of the soft portion 31E protrudes from the hard portion 30H exposed on the front surface side.
  • the other soft portion 31E is substantially flush with the hard portion 30H exposed on the front surface side.
  • the grip portion 30 includes a soft portion 32E at the center in the width direction on the back surface side (refer to Figs. 1 and 2 ).
  • the soft portion 32E constitutes a portion of the soft portion E.
  • the soft portion 32E has substantially the same outer contour as the outer contour of the soft portion 31E in the front view. That is, the soft portion 32E gradually narrows from the boundary with the sensing portion 70 toward the rear end side, and then extends at a substantially constant length. In a rear view, a side edge of the soft portion 32E and a side edge of the grip portion 30 on the outside in the width direction are formed at a substantially constant distance.
  • the hard portion 30H includes a hollow 32H (refer to Fig. 2 ) in which a portion of the soft portion 32E is embedded on the back surface side.
  • the hollow 32H gradually narrows from the boundary with the sensing portion 70 toward the rear end side in the rear view, and then extends at a substantially constant length.
  • a portion of the soft portion 32E protrudes from the hard portion 30H exposed on the back surface side.
  • the other soft portion 32E is substantially flush with the hard portion 30H exposed on the front surface side.
  • the soft portion 31E is provided on the front surface side of the grip portion 30 and the soft portion 32E is provided on the back surface side, the grip property when the grip portion 30 is gripped is improved.
  • the sensing portion 70 senses that the external force in the first direction orthogonal to the bristle tufting surface 11 exceeds a predetermined value (hereinafter, external force threshold value).
  • the sensing portion 70 changes a relationship between the displacement amount of the head portion 10 when a load is applied to the head portion 10 in the thickness direction on the back surface side and a repulsive force generated according to the displacement amount from an increase to a decrease in the repulsive force at a first threshold value according to the increase in the displacement amount, and stops the decrease in the repulsive force at a second threshold value where the displacement amount is larger than the first threshold value (details will be described later).
  • the sensing portion 70 includes a reversal portion 80 and an elastic deformation portion 90 which connect the neck portion 20 on the tip end side from the sensing portion 70 and the grip portion 30 on the rear end side from the sensing portion 70.
  • Fig. 3 is a cross-sectional view of the sensing portion 70 along a plane parallel to a thickness direction and the width direction.
  • Fig. 4 is a cross-sectional view of the sensing portion 70 along a plane parallel to the thickness direction and a long axis direction.
  • the elastic deformation portions 90 are each provided with gaps S on both sides of the reversal portion 80 in the width direction.
  • the gaps S include a through-hole K penetrating in the thickness direction.
  • the through-hole K is formed in a rectangular shape in a plan view extending in the long axis direction.
  • the reversal portion 80 can be reversed (easily reversed) without interfering with the periphery structure.
  • the deformation of the reversal portion 80 does not follow the deformation of the elastic deformation portion (because there is no interference)
  • the functional roles (to be described later) of the reversal portion 80 and the elastic deformation portion 90 can be made independent.
  • the degree of freedom in design for obtaining the following effects can be enhanced. For example, vibration or sound when the reversal portion 80 that will be described later is reversed can be clearly generated.
  • the above effect is further improved.
  • the vector of the load applied to a brush portion (bristle) during brushing, the direction where the gaps open, and the direction where the reversal portion 80 and the elastic deformation portion 90 are deformed are made parallel to each other (refer to Fig. 7 ), and for example, it is easy to link the generation of vibration or sound due to reversing with the brushing load.
  • the movable region of the elastic deformation portion 90 which is responsible for the bending function of the toothbrush skeleton with respect to the load during brushing can be further expanded (the tensile behavior on the front surface and the compression behavior on the back surface due to bending are unlikely to be hindered).
  • the movable region of the elastic deformation portion 90 is narrow.
  • the reversal portion 80 is not assigned an opportunity to reverse in an appropriate load range, and it is assumed that the reversal portion 80 is reversed before reaching the appropriate load range, or is not reversed even within the appropriate load range.
  • the "external force threshold value" at which the reversal portion 80 that will be described later reverses can be controlled in a fine range.
  • the gaps S may not penetrate in the thickness direction, and may be formed inside the elastic deformation portion 90 by a closed cavity extending in the long axis direction.
  • the gap S may include hollows (to be described later) that open on the front surface side or the back surface side.
  • Each elastic deformation portion 90 includes a hard portion 90H and a soft portion 90E. As illustrated in Fig. 1 , the hard portion 90H and the soft portion 90E connect a rear end of the neck portion 20 and a front end of the grip portion 30. As illustrated in Figs. 3 and 4 , a hollow (recessed portion) 71 that opens on the front surface side and a hollow (recessed portion) 72 that opens on the back surface side are provided between the pair of elastic deformation portions 90. The bottom portions of the hollow 71 and the hollow 72 on both end sides in the width direction are connected to the through-holes K. The reversal portion 80 is exposed and provided at the bottom portions of the hollow 71 and the hollow 72 at the center in the width direction.
  • the movable region of the elastic deformation portion that bears the bending function of the toothbrush skeleton with respect to the load during brushing can be further expanded, and the bending anisotropy in the thickness direction can be improved.
  • the hollows between the pair of elastic deformation portions 90 may not penetrate in the thickness direction, or may open in only one of the thickness directions.
  • a closed cavity extending in the long axis direction may be formed inside the elastic deformation portion 90, and the cavity may be interposed in the center to form a pair of elastic deformation portions in the width direction.
  • the end portions of the soft portions 90E in the long axis direction are connected to each other in the width direction on both the front surface side and the back surface side.
  • the soft portions 90E of the pair of elastic deformation portions 90 are provided at the periphery of the oval hollows 71 and 72 in the front view.
  • the rear end side of the soft portion 90E is connected to the soft portion 31E of the grip portion 30.
  • the soft portion 90E is connected in the width direction on both the tip end side and the rear end side of the elastic deformation portion 90, stress is unlikely to be concentrated on the end of the reversal portion 80 even when the reversing is repeated, and the bending is unlikely to occur.
  • the soft portion 90E is connected in the width direction, the amount of heat possessed by the soft resin (elastomer) during injection molding increases, which enhances the adhesiveness between the neck portion 20 and the sensing portion 70 (neck portion 20 and elastic deformation portion 90).
  • the anisotropy in the sensing portion 70 is increased by connecting the soft portions 90E in the width direction on both the tip end side and the rear end side of the elastic deformation portion 90.
  • the pair of elastic deformation portions 90 can be bent without twisting in the thickness direction with respect to the movement during brushing.
  • Fig. 5 is a partial front view in a vicinity of a hard portion 70H in the sensing portion 70.
  • Fig. 6 is a partial side view in the vicinity of the hard portion 70H in the sensing portion 70.
  • the hard portion 70H is formed in a rectangular shape in a plan view connecting the hard portion 20H which is the neck portion 20 and the hard portion 30H of the grip portion 30 in the long axis direction.
  • the tip end side of the hard portion 70H on the front surface side is connected to the hard portion 20H by a curved surface 73H having an arc shape in the side view.
  • the rear end side of the hard portion 70H on the front surface side is connected to the hard portion 30H by a curved surface 74H having an arc shape in the side view.
  • the arc centers of the curved surfaces 73H and 74H are located on the front surface side from the hard portion 70H in the side view.
  • the tip end side of the hard portion 70H on the back surface side is connected to the hard portion 20H by a curved surface 75H having an arc shape in the side view.
  • the rear end side of the hard portion 70H on the back surface side is connected to the hard portion 30H by a curved surface 76H having an arc shape in the side view.
  • the arc centers of the curved surfaces 75H and 76H are located on the back surface side from the hard portion 70H in the side view.
  • the hard portion 70H includes through-holes 73 provided on both sides of the reversal portion 80 in the width direction.
  • the through-holes 73 extend in the long axis direction.
  • the length of the through-hole 73 in the long axis direction is a length at which a tip end side end portion of the through-hole 73 is separated from the hard portion 20H and a rear end side end portion of the through-hole 73 is separated from the hard portion 30H.
  • the soft portion 90E is provided near the hard portion 90H in the width direction
  • the through-hole K is formed near the reversal portion 80 in the width direction.
  • the hard portion 90H since the hard portion 90H is disposed on both sides in the width direction with the reversal portion 80 as the center through the through-hole 73, even when a load is applied and the elastic deformation portion 90 is deformed, the shape of the reversal portion 80 can be maintained.
  • the reversal portion 80 of the sensing portion 70 is reversed in an attempt to release the accumulated strain energy. For example, in a case where the hard portion 70H is connected to the neck portion 20 and the grip portion 30 only by the reversal portion 80, since the energy cannot be accumulated, the hard portion 70H is immediately reversed.
  • the reversal portion 80 When the reversal portion 80 is integrally injection-molded with a first region A1 and a second region A2 that will be described later, the neck portion 20, the grip portion 30, and the hard portion 70H, the accumulated strain energy can be efficiently transferred to the reversal portion.
  • the hard portion 90H is formed on the outside of the hard portion 70H in the width direction from the through-hole 73. As illustrated in Fig. 3 , the hard portion 90H has a substantially rectangular cross-sectional shape.
  • the hard portion 90H is embedded in the soft portion 90E. Since the hard portion 90H is embedded in the soft portion 90E, the stress applied to the hard portion 90H can be relaxed from the viewpoint of strength. In addition, from the viewpoint of the degree of bending of the toothbrush 1 with respect to the load, it is possible to control the elastic behavior of the elastic deformation portion 90. In addition, the bending anisotropy of a sensing portion 70 is increased, and for example, the elastic deformation portion 90 can be bent without twisting in the thickness direction with respect to the movement during brushing.
  • Examples of the material of the hard portion H include a resin having a flexural modulus (JIS7171) of 1500 MPa or more and 3500 MPa or less, and for example, include a polyacetal resin (POM).
  • the flexural modulus of the hard portion H is more preferably 2000 MPa or more and 3500 MPa or less.
  • the material of the soft portion E preferably has a shore hardness A of 90 or less, and more preferably a shore hardness A of 50 to 80, so that the load when the snap buckling occurs is close to a recommended brushing load value.
  • the soft resin include elastomers (for example, olefin-based elastomers, styrene-based elastomers, polyester-based elastomers, and polyurethane-based thermoplastic elastomers) and silicones.
  • a styrene-based elastomer is preferable because styrene-based elastomers have excellent miscibility with polyacetal resins.
  • the reversal portion 80 extends in the long axis direction in the front view, and connects the first region A1 on the tip end side of the through-hole 73 and the second region A2 on the rear end side of the through-hole 73 in the hard portion 70H.
  • the reversal portion 80 is formed in substantially a V shape in the side view which gradually inclines toward the back surface side from both end portions in the long axis direction toward the center, in a first stable state (hereinafter referred to as a first state) illustrated in Fig. 4 in which no external force is applied to the back surface side of the head portion 10 (or an external force equal to or less than a predetermined external force threshold value that will be described later is applied). That is, in the first state, the reversal portion 80 is formed in a protrusion shape on the back surface side where the center in the long axis direction is the apex.
  • the elastic deformation portion 90 and the reversal portion 80 are elastically deformed according to the magnitude of the external force in the sensing portion 70.
  • the sensing portion 70 changes a relationship between the displacement amount of the head portion 10 according to the magnitude of the external force and a repulsive force (bending repulsive force) generated according to the displacement amount from increasing to decreasing the repulsive force at a first threshold value according to the increase in the displacement amount of the head portion 10, and stops the decrease in the repulsive force at a second threshold value where the displacement amount of the head portion 10 is larger than the first threshold value.
  • a repulsive force bending repulsive force
  • the elastic deformation portion 90 elastically deforms according to the magnitude of the external force exceeding the external force threshold value.
  • the reversal portion 80 snaps, buckles, and reverses to a second stable state (hereinafter referred to as a second state) when the neck portion 20 is deformed.
  • the reversal portion 80 is reversed in a direction that is substantially a reversed V shape in the side view which gradually inclines toward the front surface side toward the center.
  • the reversal portion 80 is formed in a protrusion shape on the front surface side where the center in the long axis direction is the apex.
  • the reversal portion 80 shifts from the first state to the second state, since the energy accumulated in the reversal portion 80 is released until the reversal portion 80 reaches the second state, the displacement amount of the head portion 10 increases, but the repulsive force decreases. In addition, since the reversal portion 80 is in a stable state when the reversal portion 80 is in the second state, the decrease in the repulsive force is stopped.
  • the reversal portion 80 snaps, buckles, and reverses from the first state to the second state, in a state where the bending strength of the sensing portion 70 is ensured.
  • the through-hole K is provided between the reversal portion 80 and the elastic deformation portion 90, the reversal portion 80 and the elastic deformation portion 90 can be deformed independently of each other, and the reversal portion 80 can be easily reversed.
  • the reversal portion 80 can be bent after only the elastic deformation portion 90 is first bent without either hindering the deformation behavior of the other.
  • the space between the reversal portion 80 and the elastic deformation portion 90 does not necessarily penetrate, and a gap S may be formed.
  • the user who grips the grip portion 30 can sense an over-brushing state in which the external force applied to the head portion 10 on the back surface side exceeds the external force threshold value.
  • the repulsive force increases in a state where the reversal portion 80 in which the decrease in the repulsive force is stopped at the second threshold value is formed in a protrusion shape on the front surface side in the second state.
  • the repulsive force increases in the state where the reversal portion 80 is formed in the protrusion shape on the front surface side in the second state, a series of brushing pressure behavior is rapidly restored even when the external force applied to the head portion 10 decreases, so that it is possible to suppress the occurrence of operational problems. Therefore, the user who grips the grip portion 30 senses the change in the repulsive force in two stages of a repulsive force that is decreased when the displacement amount of the head portion 10 exceeds the first threshold value, and a repulsive force in which the decrease is stopped when the displacement amount of the head portion 10 is at the second threshold value, and can more accurately sense the over-brushing state.
  • the sensing portion 70 maintains the same relationship between the displacement amount of the head portion 10 after release and the repulsive force as before the load is applied.
  • the values represented by B/A are preferably 0.3 or more and 0.9, and more preferably 0.65 or more and 0.85 or less. In a case where the value represented by B/A is less than 0.3, the attenuation from the repulsive force A to the repulsive force B is large, which may impair the usability. In addition, when the displacement amount of the head portion 10 exceeds the second threshold value and increases, the increase in the repulsive force is large, which may impair the usability.
  • the value represented by B/A exceeds 0.9, the attenuation from the repulsive force A to the repulsive force B is small, and the over-brushing state may not be recognized. Therefore, by setting the value represented by B/A to 0.3 or more and 0.9 or less, it is possible for the repulsive force in which the displacement amount of the head portion 10 exceeds the second threshold value and increases to be fully recognized so that the over-brushing state is perceived without impairing the usability.
  • the repulsive force A is preferably 1.0 N or more and 5.0 N or less, more preferably 1.5 N or more and 4.0 N or less, and even more preferably 1.5 N or more and 3.0 N or less. In a case where the repulsive force A is less than 1.0 N, sufficient cleaning power may not be obtained. When the repulsive force A exceeds 5.0 N (approximately 500 g), it may cause harm to the gingiva. Therefore, by setting the repulsive force A to 1.0 N or more and 5.0 N or less, a sufficient cleaning power can be secured and the harmful effect on the gingiva can be suppressed. In addition, the value of the repulsive force A is set to a value within the above preferable range and not exceeding a recommended brushing pressure that will be described later.
  • the value represented by D - C is preferably 0 mm or more and 1.5 mm or less, more preferably 0 mm or more and 1.0 mm or less, and even more preferably 0 mm or more and 0.5 mm or less.
  • the value represented by D - C exceeds 1.5 mm, the displacement amount of the head portion 10 exceeds the first threshold value and the repulsive force decreases, and thereafter the displacement amount increases until the displacement amount of the head portion 10 exceeds the second threshold value and the repulsive force increases. Therefore, the synergistic effect of recognizing the change in the repulsive force in two steps may decrease.
  • the displacement amount C of the first threshold value is preferably 28 mm or less. When the displacement amount C exceeds 28 mm, the bending amount during brushing increases, and it is difficult for the user to perform the oral cleaning. Therefore, by setting the displacement amount C to 28 mm or less, it is possible to secure the role of oral cleaning.
  • the displacement amount C of the first threshold value is more preferably 24 mm or less.
  • the lower limit value of the displacement amount C is more preferably 10 mm or more. By setting the lower limit value of the displacement amount C to 10 mm or more, the brushing load applied to the gingiva can be relaxed.
  • the repulsive force up to the displacement amount C preferably increases in proportion to the displacement amount, and more preferably the proportional relationship does not change (the degree of increase in the repulsive force is not relaxed) even when the displacement amount C is approached.
  • a rate of increase in the repulsive force for each displacement amount of 1 mm up to the displacement amount C is preferably 0.05 or more, more preferably 0.08 or more, and even more preferably 0.09 or more.
  • a rate of increase in the repulsive force until the displacement amount of the head portion 10 reaches 4 mm is preferably 0.015 or more.
  • the rate of increase in the repulsive force from the displacement amount D of the second threshold value to the displacement amount of the head portion 10 of 4 mm is less than 0.015, the increase in the repulsive force after the reversal portion 80 is reversed is poor and the usability may be impaired.
  • the reversal portion 80 includes a groove portion 81 at the center in the long axis direction on the front surface side, that is, in a region including an apex of the protrusion shape.
  • the reversal portion 80 includes a groove portion 82 at the center in the long axis direction on the back surface side, that is, in a region including the apex of the protrusion shape.
  • the groove portions 81 and 82 extend in the width direction.
  • the groove portion 81 is formed in an arc shape in the side view in which the center of the arc is disposed on the front surface side.
  • the groove portion 82 is formed in an arc shape in the side view in which the center of the arc is disposed on the back surface side.
  • the reversal portion 80 In a case where the reversal portion 80 is not provided with the groove portions 81 and 82, stress is uniformly generated in the entire reversal portion 80, and snap buckling is unlikely to occur. On the other hand, when the groove portions 81 and 82 are provided in the reversal portion 80, stress is intensively generated in the groove portions 81 and 82, and snap buckling is likely to occur.
  • the radius of the arc-shaped groove portions 81 and 82 in the side view is preferably 1 mm or more and 2 mm or less. In a case where the radius of the groove portions 81 and 82 is less than 1 mm, the reversal portion 80 may not be reversed. In a case where the radius of the groove portions 81 and 82 exceeds 2 mm, the vibration of the reversal portion 80 at the time of reversing is decreased, and it may be difficult to sense that the reversal portion 80 is in the over-brushing state.
  • the groove portion 81 is deeper than the groove portion 82.
  • the reversal portion 80 is unlikely to be reversed even in a case where the magnitude of the external force exceeds a predetermined external force threshold value.
  • the reversal portion 80 can be guided to be more likely to snap and buckle on the front surface side.
  • the reversal portion 80 is provided with the groove portions 81 and 82 in the region including the apex of the protrusion shape, the region including the apex of the protrusion shape is thinner than the other regions. Therefore, the strain energy accumulated by the deformation of the reversal portion 80 due to the external force exceeding the external force threshold value can be instantly released starting from the groove portions 81 and 82, and the reversal portion 80 can be reversed.
  • the positions of the groove portions 81 and 82 in the thickness direction can be adjusted to adjust the position where the reversal portion 80 reverses from the first state to the second state.
  • the groove portions 81 and 82 are formed in an arc shape in the side view, for example, as compared with the case where the groove portions 81 and 82 are formed in a V shape on two intersecting planes, even when the apex of the reversal portion 80 including the groove portions 81 and 82 moves in the thickness direction, the stress concentration at the apex can be relaxed.
  • the external force threshold value of the external force applied to the head portion 10 on the back surface side is, for example, an upper limit value of an appropriate brushing pressure.
  • the external force threshold value corresponds to the first threshold value in the displacement amount of the head portion 10 described above.
  • the angle ⁇ at which the reversal portion 80 is inclined to the plane parallel to the long axis direction and the width direction is preferably 5 degrees or more and 11 degrees or less, and more preferably 7 degrees or more and 11 degrees or less.
  • the inclination angle ⁇ is less than 5 degrees, since the reversal portion 80 is deformed without snap buckling, it may be difficult to sense that it is in the over-brushing state.
  • the reversal portion 80 may break and lose reversibility.
  • the thickness of the reversal portion 80 is preferably 1 mm or more and 2 mm or less, excluding the groove portions 81 and 82. In a case where the thickness of the reversal portion 80 is less than 1 mm, the reversal portion 80 does not snap and buckle when deformed, and it may be difficult to sense that it is in an over-brushing state. When the thickness of the reversal portion 80 exceeds 2 mm, it may be difficult for the reversal portion 80 to snap, buckle, and reverse due to the over-brushing pressure, or when the reversal portion 80 snaps, buckles, and reverses, the reversal portion 80 may break and lose reversibility.
  • T/t the maximum thickness of the reversal portion 80
  • t the maximum thickness of the sensing portion 70
  • the reversal portion 80 In a case where the value represented by T/t is less than 0.05, although the reversal portion 80 also deforms in a form that follows the bending of the sensing portion 70 (elastic deformation portion 90), the reversal portion 80 does not snap and buckle, and therefore it can be difficult to sense an over-brushing state. When the value represented by T/t exceeds 0.35, it may be difficult for the reversal portion 80 to snap, buckle, and reverse due to the over-brushing pressure, or when the reversal portion 80 snaps, buckles, and reverses, the reversal portion 80 may break and lose reversibility.
  • the bending strength of the reversal portion 80 is flexible at a constant ratio for the elastic deformation portion 90, and the reversal portion 80 can be operated with a slight delay for the bending of the elastic deformation portion 90 that bears the handle skeleton.
  • the reversal portion 80 can be operated with a slight delay for the bending of the elastic deformation portion 90 that bears the handle skeleton.
  • the maximum width of the reversal portion 80 is L (mm) and the maximum width of the sensing portion 70 is W (mm)
  • L/W a value represented by L/W
  • the value represented by L/W is preferably 0.05 or more and 0.35 or less, and more preferably 0.10 or more and 0.35 or less.
  • the reversal portion 80 In a case where the value represented by L/W is less than 0.05, although the reversal portion 80 also deforms in a form that follows the bending of the sensing portion 70 (elastic deformation portion 90), the reversal portion 80 is unlikely to snap and buckle, and therefore it can be difficult to sense an over-brushing state. When the value represented by L/W exceeds 0.35, the reversal portion 80 is unlikely to be deformed and reversed due to the bending of the handle body 2 that occurs in the range of normal brushing.
  • the reversal portion 80 may break and lose reversibility. That is, by setting L/W within the above ranges, the bending strength of the reversal portion 80 is made flexible at a constant ratio for the elastic deformation portion 90, and the reversal portion 80 can be operated with a slight delay for the bending of the elastic deformation portion 90 that bears the handle skeleton. Therefore, even when an excessive brushing load is applied, it is possible to control the ease of reversing of the reversal portion 80 and the timing (external force threshold value) that triggers the reversal portion 80 to reverse.
  • the length of the reversal portion 80 in the long axis direction is preferably 15 mm or more and 30 mm or less, more preferably 15 mm or more and 25 mm or less, and even more preferably 15 mm or more and 20 mm or less.
  • the position of the tip end side end portion of the reversal portion 80 is the position of the tip end side end portion of the through-hole 73.
  • the position of the rear end side end portion of the reversal portion 80 is the position of the rear end side end portion of the through-hole 73.
  • the length of the reversal portion 80 in the long axis direction is less than 15 mm, it may be difficult for the reversal portion 80 to snap, buckle, and reverse due to the normal brushing pressure, and the deformation required for snap buckling to develop may not be generated.
  • the length of the reversal portion 80 in the long axis direction exceeds 30 mm, the displacement required for snap buckling is significantly increased, which significantly reduces the usability, and the deformation behavior of the reversal portion 80 may be the same as that of the elastic deformation portion 90.
  • the reversal portion 80 is located between the outer contour of the bristle tufting surface side 11 and the outer contour of the back surface side of the elastic deformation portion 90 in the side view. More specifically, the position of the reversal portion 80 in the thickness direction is set so as not to protrude from the thickness of the elastic deformation portion 90 in the side view so that the reversal portion 80 does not form the outermost contour of the toothbrush. Therefore, for example, it is possible to prevent the reversal portion from coming into contact with the user during use. Specifically, it is preferable that the elastic deformation portion 90 be on the back surface side of the position where the thickness is halved.
  • the possibility of the apex of the reversal portion 80 protruding from the front surface on the front surface side of the elastic deformation portion 90 and coming into contact with the user's finger can be reduced.
  • the reversal portion 80 is disposed on the back surface side of the position where the thickness of the elastic deformation portion 90 is halved, when the reversal portion 80 is bent, the back surface side is compressed rather than the front surface side, and therefore energy that triggers the reversing easily accumulates, and the strain energy can be efficiently transferred to the reversal portion 80.
  • the reversal portion 80 forming a portion of the hard portion H can snap and buckle so that the over-brushing state can be perceived.
  • the flexural modulus of the reversal portion 80 to 3500 MPa or less, it is possible to prevent the reversal portion 80 from losing the reversibility due to breakage when the reversal portion 80 snaps, buckles, and reverses.
  • vibrations associated with snap buckling are intensively generated in a short time and are sensitive (sharp, large). As a result, the user can easily sense the over-brushing.
  • the moving distance of the apex of the protrusion shape in the thickness direction is preferably 0.2 mm or more and 5.0 mm or less.
  • the vibration at the time of snap buckling is decreased, and it may be difficult to sense the over-brushing state.
  • the moving distance of the apex in the thickness direction exceeds 5.0 mm, it may be difficult for the reversal portion 80 to snap, buckle, and reverse due to the over-brushing pressure, or when the reversal portion 80 snaps, buckles, and reverses, the reversal portion 80 may break and lose reversibility.
  • the vibration generated by the snap buckling is intensively generated in a short time and is sensitive (sharp, large). As a result, the user can easily sense the over-brushing.
  • the thickness of the hard portion 90H in the elastic deformation portion 90 is preferably 2.0 mm or less, and the width is preferably larger than the thickness. In a case where the thickness of the hard portion 90H is 2.0 mm or less, the hard portion 90H is in a plane stress state, and the hard portion 90H is unlikely to generate internal stress. As a result, the elastic deformation portion 90 is unlikely to break even when deformed, and the energy required for reversing the reversal portion 80 can be sufficiently accumulated.
  • the sensing portion 70 can be more easily deformed on the front surface side and the back surface side, and can be in a plane stress state where the sensing portion 70 is substantially not deformed in the long axis direction and the width direction. That is, in the toothbrush 1 of the present embodiment, the directions where the reversal portion 80 and the elastic deformation portion 90 are deformed are the thickness directions separated from each other in the width direction, and are not present on the same plane.
  • a path where the elastic deformation portion 90 is deformed due to the external force in the thickness direction and a path where the reversal portion 80 is deformed due to the external force in the thickness direction are provided in a non-interfering manner. Therefore, in the toothbrush 1 of the present embodiment, since the elastic deformation portion 90 and the reversal portion 80 are unlikely to be constrained by each other and can be deformed, it is possible to more sufficiently accumulate the energy required for the reversing of the reversal portion 80, stress is intensively generated in the reversal portion 80 (particularly the groove portions 81 and 82), and a sharp snap buckling is developed.
  • the toothbrush 1 of the embodiment since the toothbrush 1 of the embodiment is suppressed from being shaken in the width direction, the bending in the thickness direction due to brushing can be transmitted to the reversal portion 80 without loss.
  • the bending of the elastic deformation portion 90 and the reversing of the reversal portion 80 can be made independent and the timing can be shifted.
  • the elastic deformation portion 90 and the reversal portion 80 are disposed in the thickness direction, the roles of the bending of the elastic deformation portion 90 and the reversing of the reversal portion 80 may be hindered from each other.
  • the sensing portion 70 is provided so that the relationship between the displacement amount of the head portion 10 when a load is applied to the head portion 10 on the back surface side in the thickness direction and the repulsive force generated according to the displacement amount increases the repulsive force according to the increase in the displacement amount in a case where the displacement amount is equal to or less than the first threshold value, and decreases the repulsive force according to the increase in the displacement amount in a case where the displacement amount is equal to or less than the second threshold value larger than the first threshold value, and the value represented by B/A is 0.3 or more and 0.9 or less. Therefore, it is possible to fully recognize the repulsive force with high versatility and good usability and sense the over-brushing state.
  • the configuration in which the sensing portion 70 includes the elastic deformation portion 90 and the reversal portion 80 is exemplified, but the present invention is not limited to this configuration.
  • the configuration may have both a function of elastically deforming due to an external force in the thickness direction and a function of snapping and buckling.
  • Fig. 9(a) is a front view illustrating a modification example of the sensing portion 70.
  • Fig. 9(b) is a side view illustrating the modification example of the sensing portion 70.
  • Fig. 9(c) is a right side view of Fig. 9(a) .
  • the neck portion 20 and the grip portion 30 are not illustrated.
  • the sensing portion 70 of the modification example is formed in a rectangular shape in a front view.
  • the sensing portion 70 includes a hollow 70a that opens on the front surface side.
  • the sensing portion 70 includes an arcuate curved surface 70b having a protrusion shape on the back surface side in the side view.
  • the center of curvature of the curved surface 70b in the side view is further located on the front surface side in the thickness direction from the end portion of the curved surface 70b in the long axis direction.
  • the center of curvature of the curved surface 70b in the side view is located at the center of the sensing portion 70 in the long axis direction.
  • intersection angle intersection angle of a small value
  • intersection angle between the tangent of the curved surface 70b and a straight line parallel to the long axis direction in the side view is 0° (that is, parallel) at the center in the long axis direction.
  • the intersection angle between the tangent of the curved surface 70b and the straight line parallel to the long axis direction in the side view gradually increases from the center toward the end portion in the long axis direction.
  • the intersection angle between the tangent line of the curved surface 70b and the straight line parallel to the long axis direction in the side view is an acute angle or 0°.
  • the bottom surface of the hollow 70a in the side view is a curved surface 70b and a curved surface 70d disposed on the front surface side with a constant width.
  • the sensing portion 70 includes an arcuate curved surface 70c having a protrusion shape on the back surface side in the right side view.
  • the center of curvature of the curved surface 70c in the right side view is located on the front surface side in the thickness direction from the end portion of the curved surface 70c in the width direction.
  • the center of curvature of the curved surface 70c in the right side view is located at the center of the sensing portion 70 in the width direction.
  • An intersection angle (intersection angle of a small value) between the tangent of the curved surface 70c and a straight line parallel to the width direction in the right side view is 0° (that is, parallel) at the center of the width direction.
  • the intersection angle between the tangent of the curved surface 70c and the straight line parallel to the width direction in the right side view gradually increases from the center toward the end portion in the width direction. Since the center of curvature of the curved surface 70c is located on the front surface side in the thickness direction from the end portion of the curved surface 70c in the width direction in the right side view, the intersection angle between the tangent line of the curved surface 70c and the straight line parallel to the width direction in the right side view is an acute angle or 0°.
  • the bottom surface of the hollow 70a in the right side view is a curved surface 70c and a curved surface 70e disposed on the front surface side with a constant width.
  • the above-described hard resin, soft resin, metal, or the like can be used as the material of the sensing portion 70 of the modification example.
  • the above-described sensing portion 70 there is no limitation on the length and width in the long axis direction, and the maximum thickness is 5 mm or less.
  • the curved surface 70b having a protrusion shape on the back surface side in the side view and the curved surface 70c having a protrusion shape on the back surface side in the right side view are provided, and the bending strength on the back surface side in the thickness direction is large. Therefore, the back surface side is elastically deformed as an elastic deformation portion by an external force equal to or less than the external force threshold value.
  • the sensing portion 70 has a maximum thickness of 5 mm or less and is thin, when an external force exceeding the external force threshold value is transmitted, the sensing portion 70 snaps and buckles as a reversal portion and reverses to an arc shape of the protrusion shape on the front surface side.
  • the sensing portion 70 of the modification example can have both a function of elastically deforming by an external force in the thickness direction and a function of snapping and buckling without separately providing each of the elastic deformation portion and the reversal portion.
  • Example 4 is a sample of a toothbrush that does not include a soft portion of a sensing portion with respect to the sample of Example 1.
  • Example 6 is a sample that does not include a reversal portion and includes a first engaging portion having a base end located in a second region on the rear end side of the sensing portion and extending in the long axis direction toward a first region on the tip end side of the sensing portion, in which a second engaging portion having a base end is located in the first region and extending in the long axis direction toward the second region, is separated in the first direction when the external force in the first direction is equal to or less than the threshold value, and engages with the displacement of the head portion toward the back surface side opposite to the bristle tufting surface in the first direction due to the external force exceeding the threshold value, and in which the relative positional relationship in the first direction is reversed.
  • Example 7 is a toothbrush sample in which the radius of the groove portions 81 and 82 of the reversal portion is changed from 1.5 mm to 2 mm with respect to the sample of Example 1.
  • Example 9 is a toothbrush sample that includes a sensing portion of the modification example illustrated in Fig. 9 with respect to the sample of Example 1.
  • Comparative Example 1 "Tekiatsu-kun” manufactured by Wada Precision Dental Research Co., Ltd. was used as a sample.
  • Comparative Example 3 a toothbrush in which a gap S was filled with a soft resin was used as a sample with respect to the sample of Example 1.
  • the bristle tufting portions of the samples other than Comparative Example 1 had the same specifications as that of a Clinica Advantage toothbrush manufactured by Lion Corporation.
  • the grip portion 30 side was fixed from the boundary between the sensing portion 70 and the grip portion 30 so that the bristle tufting surface of the head portion was horizontal.
  • a test was performed in which a load was applied to the bristle tufting surface of the head portion on the back surface side in the thickness direction.
  • an autograph tester AGS-H, manufactured by SHIMADZU Corporation was used as an evaluation device.
  • a questionnaire was performed after each sample was used for one week. The survey was performed by 10 panelists. There were five questionnaire items of "awareness of vibration”, “usability immediately after vibration”, “harmfulness to gums”, “feeling that plaque in mouth is removed”, and “operability in mouth”, and each was evaluated on a 7-point scale. The average score obtained in each sample was used as the evaluation result and is illustrated in [Table 1]. In each evaluation, a case where the average score exceeded 4.0 was regarded as passing (OK), and a case of 4.0 or less was regarded as failure (NG). Details of each evaluation item are described below.
  • the vibration referred to here is a short and sensitive (sharp, large) vibration generated by the snap buckling.
  • the vibration was evaluated on a 7-point scale of significantly hard to feel (1 point), very hard to feel (2 points), slightly hard to feel (3 points), neither hard nor easy to feel (4 points), slightly easy to feel (5 points), very easy to feel (6 points), and significantly easy to feel (7 points).
  • the usability was evaluated on a 7-point scale of significantly bad (1 point), very bad (2 points), slightly bad (3 points), neither bad nor good (4 points), slightly good (5 points), very good (6 points), and significantly good (7 points).
  • the feeling that the plaque is removed was evaluated on a 7-point scale of the feeling is significantly lacking (1 point), the feeling is lacking (2 points), the feeling is slightly lacking (3 points), unclear (4 points), the feeling is slightly present (5 points), the feeling is present (6 points), and the feeling is significantly present (7 points) for the usability.
  • Fig. 8 is a graph illustrating the relationship between the pushing amount (mm) and the bending repulsive force (N) in the samples of Example 1, Example 4, Example 6, and Comparative Example 1 measured by the autograph tester.
  • the repulsive force A (N) at the pushing amount of the first threshold value, the repulsive force B (N) at the pushing amount of the second threshold value, the pushing amount (displacement amount) C (mm) at the first threshold value, the pushing amount (displacement amount) D (mm) at the second threshold value, B/A, and D - C (mm) are illustrated.
  • toothbrushes according to Examples 1 to 9 it is possible to fully recognize the repulsive force that is decreased when the displacement amount of the head portion 10 exceeds the first threshold value, and the stop of the decrease in the repulsive force when the displacement amount of the head portion 10 is at the second threshold value, and to sense the over-brushing state, without impairing the usability.
  • the value of the repulsive force A was within the range of 1.0 N or more and 5.0 N or less in the samples of Examples 1 to 9, and the value of the repulsive force A was outside of the range of 1.0 N or more and 5.0 N or less in the sample of Comparative Example 3.
  • the larger the value of the repulsive force A the greater the harmfulness to the gingiva.
  • the sample of Comparative Example 5 in which the value of the repulsive force A exceeded 5.0 N failed the evaluation of the harmfulness to the gums.
  • the samples of Examples 1 to 9 in which the value of the repulsive force A was in the range of 1.0 N or more and 5.0 N or less passed both of the evaluation of "feeling that plaque in mouth is removed" and the evaluation of "harmfulness to gums". Therefore, the toothbrushes according to Examples 1 to 9 can develop sufficient plaque removing force while suppressing irritation to the gingiva.
  • the configuration in which the sensing portion 70 is provided between the neck portion 20 and the grip portion 30 is illustrated, but the invention is not limited to this configuration.
  • the sensing portion 70 may have a configuration provided in the neck portion 20 or a configuration provided in the grip portion 30.
  • the invention is not limited to this configuration, and a configuration in which a plurality of reversal portions 80 are provided may be provided.
  • one is formed to have a thickness and inclination angle ⁇ that are reversed at the upper limit value of the appropriate brushing load, and the other is formed to have a thickness and inclination angle ⁇ that are reversed at the lower limit value of the appropriate brushing load. Therefore, it is possible to easily define both the upper limit value and the lower limit value of the brushing load.
  • the reversal portion 80 may be configured to be reversed in the width direction, or in a diagonal direction orthogonal to the long axis direction and intersecting the width direction and the thickness direction.
  • the reversal portion 80 is reversed in the diagonal direction, it is possible to sense over-brushing during brushing by a rolling method.
  • the present invention can be applied to a toothbrush.
EP19905494.1A 2018-12-27 2019-12-26 Brosse à dents Pending EP3903632A4 (fr)

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JP6914024B2 (ja) * 2016-10-28 2021-08-04 ライオン株式会社 歯ブラシおよび歯ブラシ製造方法
US10638829B1 (en) * 2018-11-14 2020-05-05 Zent, Llc Protective toothbrush

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JPWO2020138280A1 (ja) 2021-11-04
TW202034819A (zh) 2020-10-01
EP3903632A4 (fr) 2022-09-21
US20220015531A1 (en) 2022-01-20
CN113194784A (zh) 2021-07-30
CN113194784B (zh) 2023-04-14
WO2020138280A1 (fr) 2020-07-02
KR20210104678A (ko) 2021-08-25

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