Brush head assembly
A brush head assembly comprising: a hard platen; a plurality of bristle tufts, each of which comprises a plurality of bristle strands, each bristle tuft having a proximal end and a free end; and a flexible matrix at least partially comprised of a shear-thickening material for coupling the plurality of bristle tufts to the hard platen, wherein the flexible matrix is arranged such that there is shear-thickening material between the proximal ends of the plurality of bristle tufts and the hard platen. A method of manufacturing the brush head assembly for use with a personal care appliance.
1. A brush head assembly comprising:
a hard platen;
a plurality of bristle tufts, each of which comprises a plurality of bristle strands, each bristle tuft having a proximal end and a free end; and
a flexible matrix at least partially comprised of a shear-thickening material for coupling the plurality of bristle tufts to the hard platen, wherein the flexible matrix is arranged such that there is shear-thickening material between the proximal ends of the plurality of bristle tufts and the hard platen.
2. The brush head assembly of claim 1 , wherein the proximal end of the bristle strands in each bristle tuft are formed into a proximal end portion that is in contact with the flexible matrix.
3. The brush head assembly of claim 1 , further comprising at least one retention element to secure the bristle tufts in the flexible matrix, the retention element at least partially encompassed in the flexible matrix.
4. The brush head assembly of claim 1 wherein the shear-thickening material is soft or deformable without application of motion or vibration to the brush head.
5. The brush head assembly of claim 1 wherein the shear-thickening material is in the form of a foam or polymer that is soft or deformable without application of motion or vibration to the brush head assembly.
6. The brush head assembly of claim 1 , wherein the shear-thickening material is rigid with application of motion or vibration to the brush head.
7. The brush head assembly of claim 1 , wherein the shear-thickening material is such that the rigidity or viscosity of the shear-thickening material increases with increasing frequency of a vibration applied to the brush head.
8. The brush head assembly of claim 7 , wherein the vibration frequency is greater than 50 Hz.
9. The brush head assembly of claim 7 , wherein the vibration frequency is in the range of 250-300 Hz.
10. The brush head assembly of claim 1 , wherein the flexible matrix is bonded to at least a portion of the hard platen.
11. The brush head assembly of claim 1 , wherein the flexible matrix is bonded to the proximal end of the bristle tufts.
12. A personal care appliance comprising:
a handle including a drive train and a drive shaft;
a motor controller for controlling operation of the drive train to produce a mechanical stimulus; and
a brush head assembly as claimed in claim 1 .
13. A method of manufacturing a brush head assembly for use with a personal care appliance, the method comprising:
providing a hard platen and a plurality of bristle tufts, each of which comprising a plurality of bristle strands, each bristle tuft having a proximal end and a free end; and
coupling the plurality of bristle tufts to the hard platen using a flexible matrix at least partially comprised of a shear-thickening material, wherein the flexible matrix is arranged such that there is shear-thickening material between the proximal ends of the plurality of bristle tufts and the hard platen.