Patent Publication Number: US-6654979-B2

Title: Electric toothbrush

Description:
This is a Divisional of Ser. No. 09/603,500 filed Jun. 26, 2000, now U.S. Pat. No. 6,446,295. 
    
    
     The present invention concerns an electric toothbrush comprising a handle and a head, characterised in that the head has a rubbery cleaning element. 
     Electric toothbrushes are well known in the art and typically comprise a motor element housed within the brush handle and a head, which is usually replaceable. 
     Most electric brushes effect cleaning by rapidly moving the brush head (hereinafter known as oscillating brushes) but some merely vibrate (hereinafter known as vibrating brushes). 
     There is a multitude of oscillating brushes on the market and some have particular oscillating patterns, e.g. longitudinally oscillating elements, or they may have multiple brush heads, such as the one marketed by Phillips under the tradename ‘Plaque Remover ®’, which comprises a rotating head and a laterally oscillating array of bristles distal to the brush handle. 
     An example of a vibrating brush is sold by J&amp;J under the tradename ‘Powerbrush®’. 
     Manual brushes with rubbery bristles are well-known in the prior art and may provide a polishing, cleaning or gum managing benefit. For example, WO 98/22000 (Asher) discloses a brush comprising at least one plaque removing member which is surrounded by a plurality of bristles. 
     In our co-pending application GB 9912923.1 we describe a brush comprising a housing for a motor and a brush head which is flexible. 
     SUMMARY OF THE INVENTION 
     We have found that the benefits provided by a brush head comprising a rubbery cleaning element can be greatly enhanced if provided on an electric toothbrush. 
     An object of the present invention is to provide a cheap electric toothbrush, which provides an improved cleaning benefit. 
     We have found that an electric toothbrush can provide an improvement upon the prior art when the brush head comprises rubbery cleaning elements. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The invention will now be described with reference to the non-limiting figures in which: 
     FIG. 1 is a side elevational view of an electric toothbrush according to the present invention; 
     FIG. 2 is a front elevational view of the toothbrush according to FIG. 1; and 
     FIG. 3 is a partial view of a brush head for rotational movement. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Accordingly, the present invention provides an electric toothbrush, characterised in that it comprises a rubbery cleaning element. 
     By rubbery cleaning element is meant a cleaning element, e.g. a bristle, which is made of a rubbery material ie. one which exhibits flexible and resilient characteristics. 
     In a preferred embodiment, the rubbery cleaning element is in the form of fingers which are generally thicker than conventional nylon bristles. 
     In a particularly preferred embodiment, the rubbery cleaning element is in the form of a flap or lamella. Such a flap or lamella may be either linear or arcuate in a cross-section parallel to the brush head base. 
     Depending on the size of the rubbery element it is envisaged that any number of rubbery elements may be present on the brush and may be in combination with any member of bristle tufts. 
     A rubbery cleaning element is an enlarged bristle made of a rubbery material. By rubbery is meant that the material has some elastic nature. Given that electric toothbrushes vibrate at an extremely high frequency it is anticipated that a high elastic nature is not necessary and a material with a Shore A hardness of less than 100 is suitable for use in the present invention. 
     In a preferred embodiment, the rubbery material has a Shore A hardness of less than 100, more preferably less than 80, and especially less than 55. Preferably the rubbery material also has a minimum Shore A hardness of 15, more preferably 25. 
     Particularly suitable rubbery material include elastomeric materials such as those described in WO97/20484, the contents of which are incorporated by reference. 
     It is also envisaged that the head of the brush according to the invention is replaceable. 
     The rubbery cleaning element may also serve to provide a polishing benefit to the teeth surfaces. 
     It is also possible for the rubbery cleaning element to additionally comprise abrasive materials such as silicas to enhance the cleaning or polishing benefit. 
     In an alternative aspect the invention provides an electric toothbrush with improved sensory benefits. The brush according to the invention provides an improved feel in the oral cavity, due to the presence of the rubbery material. This is particularly so when the non-bristle bearing surfaces of the head is significantly covered by a rubbery material and contacts the buccal lining. This sensory benefit is seen as an important consumer positive. 
     The head of the brush according to the invention may either be a vibrating head or an oscillating head. For example, the rubbery cleaning element may merely vibrate to effect cleaning or it may be fixed on a rotating head. 
     FIG. 1 is an elevation of a brush according to the invention. It shows a brush ( 1 ) comprising a handle ( 2 ) and a head ( 3 ). The head ( 3 ) comprises a bristle bearing portion ( 4 ) and a neck portion ( 5 ). The bristle bearing portion ( 4 ) comprises a rubbery cleaning element ( 6 ) and conventional bristle tufts ( 7 ). 
     Typically, the handle ( 2 ) will comprise a motor element which vibrates or oscillates at least the brush head ( 3 ). 
     FIG. 2 is a plan view of the brush shown in FIG. 1 showing the layout of the rubbery cleaning members and the conventional bristle tufts. 
     FIG. 3 is a plan view of a brush head designed to rotate around a central point ( 9 ). 
     Shown are rubbery cleaning elements in the form of fingers ( 10 ) and lamellae ( 8 ) as well as conventional bristles ( 7 ).