Electric Toothbrush And Brush Head For An Electric Toothbrush

Abstract

A brush head for an electric toothbrush is disclosed. The brush head includes a plate-shaped bristle support including mounting means for the movable mounting of the bristle support, the bristle support carrying at least two outer bristle tufts and at least two inner bristle tufts, the outer bristle tufts having a greater height than the inner bristle tufts, such that in the working surface defined by the free ends of the tufts there is formed a central depression which has a groove-shaped concave bottom curved in one direction and extending substantially straight in the direction vertical thereto. At least one of the outer bristle tufts has a chamfer on its outer lying edge of its free end close to the circumferential side of the bristle support.

1 . A brush head for an electric toothbrush, comprising:
 a bristle support including mounting means for the movable mounting of the bristle support, the bristle support carrying at least two outer bristle tufts and at least two inner bristle tufts, the outer bristle tufts having a greater height than the inner bristle tufts,   a working surface being defined by the free ends of the bristles of the outer and inner bristle tufts and having a central depression which has a groove-shaped concave bottom curved in one direction, and   wherein at least one of the outer bristle tufts has a chamfer on an outer lying edge of its free end close to the circumferential side of the bristle support.   
     
     
         2 . The brush head according to  claim 1 , wherein the curvature of the central depression is continuous. 
     
     
         3 . The brush head according to  claim 1 , wherein the mounting means are suitable to enable a rotational oscillatory movement of the bristle support. 
     
     
         4 . The brush head according to  claim 1 , wherein the chamfer is inclined relative to a flat section of the free ends of the at least two outer bristle tufts at an angle (γ) ranging between about 20° and about 60°. 
     
     
         5 . The brush head according to  claim 1 , wherein the chamfer defines a plane surface. 
     
     
         6 . The brush head according to  claim 1 , wherein the chamfer has a curvature. 
     
     
         7 . The brush head according to  claim 1  wherein the at least two outer bristle tufts are inclined towards the circumferential side of the bristle support at an acute angle (α) in the range from about 1.5° to about 15°. 
     
     
         8 . The brush head according to  claim 1  wherein the at least two outer bristle tufts are trapezoidally shaped as seen in a longitudinal sectional view of the at least two outer bristle tufts, with the free end of the respective outer bristle tuft being wider than its inner end. 
     
     
         9 . The brush head according to  claim 1 , wherein an inner flank of the at least two outer bristle tufts, which faces the inner bristle tufts, extends substantially vertically to the surface of the bristle support and an outer flank of the at least two outer bristle tufts is inclined towards the circumferential side of the bristle support at an acute angle to a vertical on the bristle support. 
     
     
         10 . The brush head according to  claim 1 , wherein the at least two outer bristle tufts on a first circumferential side of the bristle support are of greater height than on a second circumferential side of the bristle support. 
     
     
         11 . The brush head according to  claim 1  wherein the mounting means of the bristle support define an axis of rotation for the bristle support suitable for producing an oscillatory rotational motion of the bristle support. 
     
     
         12 . The brush head according to  claim 1 , wherein the at least two outer bristle tufts are arranged on opposing sides of the central depression in a direction in which the groove-shaped concave bottom of the central depression has its curvature. 
     
     
         13 . The brush head according to  claim 1  wherein the groove-shaped bottom, which is formed by the free ends of the bristles, is constructed as part of a cylinder shape. 
     
     
         14 . The brush head according to  claim 13  wherein the radius of a section through the groove-shaped bottom or the cylinder shape is about 9 mm to about 15 mm. 
     
     
         15 . The brush head according to  claim 1  wherein the free ends of the at least two inner bristle tufts have inclined end surfaces, with different inner bristle tufts having end surfaces with different inclinations, such as to form the groove-shaped bottom. 
     
     
         16 . The brush head according to  claim 1  wherein the groove-shaped bottom of the central depression is shaped to raise more to one circumferential side of the bristle support than to the opposing circumferential side, exhibiting a substantially banana-shaped, asymmetric curvature. 
     
     
         17 . The brush head according to  claim 1  wherein a step-like jump in height between the at least two outer bristle tufts and the adjacent areas of the central depression is from about 0.5 mm to about 2 mm. 
     
     
         18 . A brush head for an electric toothbrush, comprising:
 a bristle support having mounting means for the movable mounting of the bristle support, the bristle support carrying at least two outer bristle tufts and at least two inner bristle tufts, the outer bristle tufts having a greater height than the inner bristle tufts,   a working surface being defined by the free ends of the bristles of the outer and inner bristle tufts and having a central depression which has a groove-shaped concave bottom that is continuously curved in one direction, and   wherein a step-shaped jump in height is provided between the central depression and the at least two outer bristle tufts.   
     
     
         19 . The brush head according to  claim 18 , wherein the height of the step-shaped jump in height is between about 0.5 mm and about 2.0 mm. 
     
     
         20 . The brush head according to  claim 18 , wherein at least one of the outer bristle tufts has a chamfer at the outer lying edge of its free end.