EP0201232A1

EP0201232A1 - Improvements in or relating to toothbrushes

Info

Publication number: EP0201232A1
Application number: EP86302899A
Authority: EP
Inventors: Joseph Lai Ming
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-05-07
Filing date: 1986-04-17
Publication date: 1986-11-12
Also published as: GB8609437D0; GB2178304A; JPS61263407A; GB8511478D0

Abstract

© A toothbrush comprises a handle (1) and bristles (2) defining a brushing surface which is generally convex as viewed in transverse cross-section, in order to improve cleaning at the tooth-gum junction.

Description

THIS INVENTION relates to improvements in or relating to toothbrushes. Previously proposed toothbrush designs concerned either the shape of the handle or the hardness of the material(s) used for the bristles. The brushing surface is conventionally flat and parallel to the plane of the handle so that the bristles present a uniformly rectangular transverse cross section. It has also been proposed to provide a tuft of relatively long bristles at the front end of the brush, that is to say, the end remote from the handle. However, the transverse cross-sectional shape of the brushing surface has not been varied.
U.K. Patent No. 542715 (Jackson) discloses a toothbrush in which the bristles on the outside of the brush are shorter than the central bristles, thus causing the height of the brush to decrease towards the edges of the brush. The shorter outer bristles have the purpose of mutually reinforcing the central, longer bristles. The tops of the central bristles form a flat brushing surface, but the outer shorter bristles do not engage the teeth and so are not involved in the brushing operation.
The primary purpose of tooth-brushing is to get rid of organic matter between the gum and the teeth to avoid build-up of dental plaque. A recommended brushing method is to brush at an angle to the tooth and gum junction whilst making horizontal movements. However, with a conventional brush having a flat surface, one side of the brush meets with more pressure whilst the other side is left unused. Furthermore, cleaning is not very effective between the tooth and gum.
Accordingly, in one aspect of the present invention, the brushing surface is set at an angle to the plane of the handle, as viewed in transverse cross-section. However, because assymetrical, this does not allow for brushing upper, lower, inside and outside surfaces with the same brush. A preferred aspect of the invention therefore provides a toothbrush having a generally convex brushing surface, as viewed in transverse cross section. The brushing surface may either be curved or bevelled.
For a better understanding of the present invention, and to show how the same may be put into effect, reference will now be made, by way of example, to the accompanying drawing, in which:

FIGURES IA and IB are an end view of a prior art toothbrush and a corresponding schematic view thereof in use,
FIGURES 2, 3 and 4 are end views of toothbrushes in accordance with the present invention,
FIGURE 5 is a corresponding schematic view of the toothbrush of Figure 2 in use, and
FIGURE 6 is a corresponding schematic view of the toothbrush of Figure 3 or Figure 4 in use.

Referring now to the drawing, Figure I A shows a conventional toothbrush of uniformly rectangular transverse cross section. As can be seen in Figure IB, cleaning is not very effective at the junction between tooth and gum.
Figures 2 and 5 show a toothbrush in accordance with the invention in which the brushing surface is set at an angle to the plane of the handle 1, as viewed in transverse cross section. A similar effect could be obtained by keeping the brushing surface parallel to the plane of the handle I but setting the bristles 2 at an angle other than 90° to the plane of the handle I so that the bristles present a uniformly parallelogrammatic transverse cross-section.
Figures 3, 4 and 6 show toothbrushes in accordance with the invention in which the brushing surface is generally convex as viewed in transverse cross section. In Figure 3, the brushing surface is curved, whilst Figure 4 shows a toothbrush having an angled brushing surface made up of a number of smaller surfaces. The bristles 2 in both cases are shown as of varied length. However, the bristles 2 could be of constant length and the convex brushing surface achieved by providing a correspondingly convex handle I. Also, although the bristles 2 are shown as parallel, they could be splayed so as to extend along radii of curvature of the brushing surface.
As can be seen in Figures 5 and 6, the toothbrushes of the present invention improve cleaning at the tooth-gum junction.
The handle I may be a manually held handle or adapted to be connected to the vibrating mechanism of an electric toothbrush and can comprise any suitable material such as a tough moulded plastics material. The bristles can comprise any suitable material such as bristle or a synthetic material such as nylon.
In the description, features common to the various embodiments have been given the same reference numerals.
The features disclosed in the foregoing description, in the following claims and/or in the accompanying drawings may, both separately and in any combination thereof, be material for realising the invention in diverse forms thereof.

Claims

l. A toothbrush, which toothbrush comprises a plurality of bristles, which are substantially straight and substantially parallel to each other, at least some of the free ends of the bristles defining a brushing surface, and an elongate support means therefor comprising a handle, wherein, as viewed in cross-section, taken transverse to the longitudinal axis of the handle, the brushing surface defines at least one line which is inclined relative to the bristles and/or is curved.
2. A toothbrush according to Claim I, wherein, as viewed in transverse cross-section, the brushing surface defines a plurality of lines which are inclined relative to the bristles.
3. A toothbrush according to Claim I or 2, wherein, as viewed in transverse cross section, the brushing surface forms an obtuse angle with the bristles at one or both extremities of the brushing surface.
4. A toothbrush according to Claim 1, 2 or 3, wherein, as viewed in transverse cross-section, the brushing surface is convex.
5. A toothbrush according to any one of the preceding claims, wherein, as viewed in transverse cross-section, the bristles vary in length.
6. A head for a toothbrush, which head comprises a plurality of bristles, at least some of the free ends of which define a brushing surface, and is adapted to be mounted on elongate support means such that, as viewed in transverse cross-section, the brushing surface defines at least one line which is inclined relative to the bristles and/or is curved.