| 摘要 |
1. A toothbrush which comprises a head, from a bristle face of which extend bristles, integrally linked at the base end of the head to the head end of a grip handle, with a neck region between the head and the grip handle, all being disposed along a longitudinal axis and made integrally of plastics material, characterised in that in the neck region there is an integral thinned part which is of thinned cross section relative to the longitudinally adjacent pans of the neck and/or the head to which it is connected, the said part being laterally surrounded by a mass of elastomeric material bonded to the plastics material, the mass being of a shape which bulges laterally beyond the line of the surface of the longitudinally adjacent parts of the neck or the head to which it is connected. 2. A toothbrush according to Claim 1 characterised in that the thinned part is located at or immediately longitudinally adjacent to the base of the head, and links the head to the neck. 3. A toothbrush according to Claim 1 or 2 characterised in that the thinned part is in the form of a thin spine of the plastics material extending longitudinally between facing surfaces of the said longitudinally adjacent pans of the toothbrush. 4. A toothbrush according to any one of Claims 1, 2 or 3 characterised in that the part of the head, or of the neck to which the head end of the thinned pan is connected is of a concave shape as viewed in plan, to the deepest pan of which the thinned pan connects. 5. A toothbrush according to Claim 4 characterised in that the pan,. the head or neck to which the handle end of the thinned pan is connected is of a corresponding convex shape. 6. A toothbrush according to Claim 4 characterised in that the pan of the head or neck to which the handle end of the thinned pan is connected is also of a concave shape of opposite curvature, so as to form a rounded cavity bounded in pan at its longitudinal ends by these two respective concave surfaces. 7. A toothbrush according to any one of the preceding Claims characterised in that the thinned pan bridges a widthways aligned chasm across the neck of the toothbrush, or between the head, and the neck of the toothbrush. 8. A toothbrush according to Claim 7 characterised in that the chasm is a parallel sided slot or a curved sided slot. 9. A toothbrush according to Claim 8 characterised by the chinned pan being connected at head end to the base end of the thinned part is connected being of a concave shape, to the deepest pan of which the thinned par- connects, and the pan of the head or neck to which the handle end of the thinned pan is connected being of a corresponding convex shape, such that the facing surfaces of the head end of the neck and the base end of the head define a curved chasm between them. 10. A toothbrush according to any one of the preceding Claims characterised in that as viewed from the side the said facing surfaces are aligned at a non-perpendicular angle to the longitudinal toothbrush axis. 11. A toothbrush according to Claim 10 characterised in that the surfaces of the chasm between the head end of the neck and the base end of the head are inclined at an angle such that their extrapolation converges on the bristle surface side of the toothbrush. 12. A toothbrush according to any one of the preceding Claims characterised in that the thinned part bridges the longitudinally adjacent parts of the neck and/or the head nearer to one or other of the bristle face or the reverse face of the toothbrush. 13. A toothbrush according to any one of the preceding Claims characterised in that the cross section of the thinned part is 0.1-0.75 of the cross section of the immediately longitudinally adjacent parts of the toothbrush. 14. A toothbrush according to any one of the preceding Claims characterised in that the mass of elastomeric material is a rounded mass. 15. A toothbrush according to any one of the preceding Claims characterised in that the mass bulges laterally, in the direction perpendicular to the longitudinal axis of the toothbrush and generally in the bristle direction, to between about 1.5 to 4 times the thickness of the immediately adjacent part of the neck and/or the base end of the head. 16. A toothbrush according to any one of the preceding Claims characterised in that the thinned part links the head to the neck, and is in the form of a longitudinal spine bridging a curved chasm with the concave side of the chasm adjacent to the head and the convex side of the chasm adjacent to the neck. |
