US 12,144,415 B2
Toothbrush
Ryosuke Hachisuka, Tokyo (JP)
Assigned to Lion Corporation, Tokyo (JP)
Appl. No. 17/417,023
Filed by Lion Corporation, Tokyo (JP)
PCT Filed Dec. 26, 2019, PCT No. PCT/JP2019/051085
§ 371(c)(1), (2) Date Jun. 21, 2021,
PCT Pub. No. WO2020/138270, PCT Pub. Date Jul. 2, 2020.
Claims priority of application No. 2018-246149 (JP), filed on Dec. 27, 2018.
Prior Publication US 2022/0047064 A1, Feb. 17, 2022
Int. Cl. A46B 5/00 (2006.01); A46B 5/02 (2006.01); A46B 9/04 (2006.01)
CPC A46B 5/0066 (2013.01) [A46B 5/007 (2013.01); A46B 5/02 (2013.01); A46B 9/04 (2013.01); A46B 2200/1066 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A toothbrush comprising:
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;
a neck portion disposed between the bristle tufting surface and the grip portion; and
an anisotropic deformation portion provided on a rear end side from the bristle tufting surface, in which a bending strength in a first direction orthogonal to the bristle tufting surface is smaller than a bending strength in a second direction orthogonal to the long axis direction and the first direction,
wherein the anisotropic deformation portion includes an elastic deformation portion that connects a first region on the tip end side of the anisotropic deformation portion and a second region on the rear end side of the anisotropic deformation portion and is elastically deformable in the first direction and the second direction,
any bending load when the head portion is displaced in the first direction with a reference displacement amount of 10 mm, 20 mm, or 30 mm in a state where the grip portion is supported is lower than a bending load when the head portion is displaced in the second direction with a reference displacement amount of 10 mm in a state where the grip portion is supported,
wherein the elastic deformation portion includes a first hard portion made of a hard resin and connecting the first region and the second region, and a soft portion made of a soft resin and covering a periphery of the hard portion,
wherein the anisotropic deformation portion includes a recessed portion that is open on at least one of a surface on one side and a surface on the other side in the first direction, and provided side by side with the elastic deformation portion in the second direction,
two of the elastic deformation portions are provided,
wherein the elastic deformation portions are provided on both sides in the second direction with the recessed portion interposed therebetween, and
wherein the first hard portion includes a first portion whose thickness in the first direction is thinner at the center side than at both ends in the long axis direction on one side and the other side of the first direction, respectively, and a second portion connecting the center sides of the first portion.