Brushing – scrubbing – and general cleaning – Implements – Brush or broom
Reexamination Certificate
1998-05-26
2001-01-30
Till, Terrence R. (Department: 1744)
Brushing, scrubbing, and general cleaning
Implements
Brush or broom
C015S172000, C300S021000
Reexamination Certificate
active
06178582
ABSTRACT:
This invention relates to toothbrushes, in particular to toothbrushes having a flexibly linked region in their head.
BACKGROUND OF THE INVENTION
Toothbrushes having a flexibly linked region in their head are known. For example WO 92/17093 discloses a toothbrush in which the head is divided into two or more segments which are flexibly and resiliently linked to each other and/or to the handle of the toothbrush. A particular form of the toothbrush of WO 92/17093 has a head which has grooves in the reverse face of the head from which the bristles extend, these grooves being filled with an elastomeric material to modulate the flexibility. The embodiments disclosed in have their grooves distributed in a generally uniform distribution over the reverse face of the head, or around the longitudinal mid point of the head, so as to enable the whole head to accommodate itself to the curved shape of the teeth. WO 96/02165 discloses toothbrushes with flexible heads similar in construction to those of WO 92/17093, and having a generally concave profile of bristle ends. DE-G 87 05 474.4 discloses a toothbrush in which the tip region of the head is hinged to a base region of the head and an operating button on the handle allows the tip region to fold relative to the base region.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a toothbrush in which the flexibility of the head is concentrated in the tip of the head remote from the handle, so as to improve the ability of the toothbrush to clean surfaces of the teeth which face the back of the mouth.
According to this invention a toothbrush comprises a handle with a head, the head having a base end facing the handle and a tip end remote from the base end, the head adjoining the handle at the base end of the head, the head and handle being disposed along a longitudinal toothbrush axis, the head having bristles extending from a bristle face of the head, characterised in that the head comprises a substantially rigid base region adjoining the toothbrush handle and extending from the base end of the head to a link region situated between the base end and the tip end, and a tip region extending from the tip end of the head to the link region, both the base region and tip region being bristle bearing, the tip region being flexibly and resiliently linked at the link region to the base region.
DETAILED DESCRIPTION OF THE INVENTION
The above-described construction of toothbrush concentrates flexibility of the head at the tip end of the toothbrush, the linking of the tip region and base region is preferably in a manner which enables the tip region to fold or pivot resiliently relative to the base region during toothbrushing. The link provided at the link region between the tip region and the base region allows the tip region to fold or pivot during use about a fold or pivot axis which is in the plane of the bristle face and generally transverse to the longitudinal toothbrush axis such that bristles on the tip region can lean backwards, i.e so that the free ends of bristles in the tip region swing toward the handle, assisting the bristles to clean surfaces of the teeth which face the back of the mouth. The flexible linking also helps to prevent excessive brushing pressure from being applied during toothbrushing.
Normally the head of the toothbrush will adjoin the handle of the toothbrush via a neck region between the base of the toothbrush head and the part of the handle which is held during use.
The base region is substantially rigid, that is, during the operation of brushing the teeth the base region does not significantly flex beyond the usual limits of flexing of a plastics material toothbrush head.
The link region is preferably in the longitudinal half of the head furthest from the base of the head. Suitably the base region extends for at least 60%, for example at least 75% of the distance between the base end of the head and the tip of the head.
The tip region may also be substantially rigid, so that the tip region does not itself significantly flex apart from its folding or pivoting relative to the base region. The tip region may be of a variety of shapes accommodated to the shape of the tip of the head, e.g. circular, triangular (including ogival), rectangular, elongate, lozenge shape etc.
In its non-stressed condition, i.e when not being used, the bristle face of the tip region and base region of the toothbrush of this invention may be substantially coplanar, i.e with a substantially 180° angle between them. In a preferred embodiment of the toothbrush of this invention the bristle face of the tip region forms an angle of less than 180° with the bristle face of the base region, e.g 150°-179°, suitably 155°-170°. A suitable angle is one in which the free ends of the bristles on the handle side of the tip portion are in close proximity to, e.g touching, the free ends of bristles on the tip side of the base region.
The link region between the tip region and the base region in one embodiment of this invention comprises an aperture, space or chasm in the head material between the tip and base regions which is bridged by means of one or more thin links of flexible and resilient plastics material. In this construction the head is effectively in two regions linked by such links. Such links may comprise thin spines, thin strips, or a continuous thin membrane, made of a both flexible and resilient plastics material. These spines, thin strips or membrane may be in the same plane as a substantially planar head, or may slope or may be curved out of planarity. The plastics material may be the same plastics material as the tip and base regions but being flexible by virtue of thinness, e.g. the tip, base and bridge(s) may be integrally moulded.
In another embodiment of this invention the link region between the tip region and the base region may comprise a composite region between the tip region and base regions, the composite region having structural elements made of both plastics material and an elastomeric material. For example the composite region may comprise an aperture, space or chasm in the head material between the tip and base regions which is bridged by means of a combination of thin spines, strips or a continuous membrane of a both flexible and resilient plastics material, e.g integral with the head, and also by an elastomeric material in the aperture, space or chasm. These spines, thin strips or membrane may be in the same plane as a substantially planar head, or may slope or may be curved or folded out of planarity. In this construction the head is effectively in two regions linked by such links, and the links are embedded in a covering layer of rubber.
Such a composite region may for example comprise a net, ladder, latticework, cellular or trellis structure of plastics material integral with the material of the head, with interstices containing the elastomeric material. Such a composite region may for example comprise one or more, for example two, strips of a plastics material integral with the material of the head, the strips being thinner than the thickness of the head, and extending between the tip region and base region to bridge an aperture, space or chasm between the tip region and the base region, the aperture, space or chasm also containing an elastomeric material, suitably bonded to the sides of the space and to the strips and suitably substantially filling the aperture, space or chasm, optionally also bulging above the surface of the surrounding plastics material of the head . Relative to the thickness of the toothbrush head the strips in such a construction may be closer to the bristle face than to the back of the head. The plastics material parts in such a composite region may be thick enough to contribute materially to the flexibility and resilience of the link region, or alternatively they may be so thin as to contribute little to the flexibility and resilience of the link region, and may thus serve simply to retain the tip and head regions together before the elastomer is added.
In another embodiment of this inventi
Finnegan Henderson Farabow Garrett & Dunner
SmithKline Beecham Consumer Healthcare GmbH
Till Terrence R.
LandOfFree
Toothbrush comprising a resilient flex region does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Toothbrush comprising a resilient flex region, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Toothbrush comprising a resilient flex region will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2509241