Abstract:
The present invention relates to a replacement brush head for an electromagnetic driven toothbrush and to a method of manufacturing such a brush head. The brush head includes a bristle carrier, where the bristle carrier has blind-end holes in which a plurality of tooth cleaning bristles can be fixedly attached. The bristles are arranged in inwardly centered rows, one behind the other. Bristles in outer rows are arranged in groups on both sides of the bristle carrier. Bristle groups are arranged with an outward leaning angle for efficient cleaning of the tooth neck area and gum pockets. Bristles in the inner rows can be shorter than the ones in the outer rows.

Description:
FIELD OF INVENTION 
       [0001]    The present invention generally relates to replacement brush heads, for example for use with an electromagnetic assembly. Additionally, a method of manufacture of the same is described herein. 
       BACKGROUND OF THE INVENTION 
       [0002]    Plaque is the main cause to gingivitis and other gum diseases. It is a sticky material made of bacteria, mucus, and food debris and deposits particularly in the grooves and gum pockets evolved between the gum and teeth. Being concealed, technical level, conventional tooth brushes with right-angle bristles block rather than remove it when brushing the teeth. What is needed is a brush which is designed to remove plaque buildup at the neck of the tooth. 
       SUMMARY OF THE INVENTION 
       [0003]    It is an object of the present invention to provide a toothbrush head. In particular, a toothbrush head for use as a replaceable toothbrush head of an electronic toothbrush. 
         [0004]    It is an aspect of the present invention to provide a toothbrush head comprising a brush head housing coupled to a brush head shaft, a movable bristle carrier coupled to a pivoting axle of the brush head housing, and a mechanical linkage assembly ( 6 ) coupled to the pivoting axel. 
         [0005]    Additionally, the bristle carrier may contain a plurality of tooth cleaning elements which form bristle tufts, where a first portion of the bristle tufts are formed in to bristle tuft groups in a the outermost row(s) of a plurality of patterned rows, the bristle tuft groups being located on opposite sides of the bristle carrier on the brush head. 
         [0006]    Furthermore, it is an aspect of certain embodiments for at least two of the bristle tuft groups in the outermost row(s) are disposed at a pivoting angle of between 5° and 45°, preferably between 20° and 30° off of a median line of the bristle carrier. 
         [0007]    Still yet it is an aspect of certain embodiments for the median line of the bristle carrier to be disposed ±0° to 45°, for example 25°, from perpendicular from the longitudinal axis of the brush head shaft. Particularly, wherein the median line is disposed perpendicular to the longitudinal axis. 
         [0008]    Furthermore, it is an aspect of certain embodiments that the bristle tuft groups are disposed in an outward leaning angle compared to a central axis of the pivoting axle. For example, wherein the outward leaning angle is between 5° and 45° and preferably between 15° and 25°. 
         [0009]    The bristle tufts may have a round cross sectional shape, or other effective cross sectional shape. The first bristle tufts can also be at least 1.5× longer, preferably between 2× and 3× longer than the second bristle tufts. 
         [0010]    Additionally, there is described herein a method of manufacturing the same. 
         [0011]    In particular it is intended to improve the brushing efficiency of the teeth neck areas and gums. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1A  shows a perspective top view of an electromagnet driven toothbrush with a brush head according to an embodiment of the present invention. 
           [0013]      FIG. 1B  shows a perspective side view of the electromagnet driven toothbrush of  FIG. 1A . 
           [0014]      FIG. 2  is a perspective front view of the brush head of  FIG. 1  showing the bristle tufts on the bristle carrier. The outer row is arranged in groups containing one or more elongated tufts which can be used in order to provide improved cleaning of the gums and teeth neck area. 
           [0015]      FIG. 3  is a sectional side view of the brush head taken along the cut lines A-A in  FIG. 1 . The figure shows the brush head, brush head pivoting axle and bristle carrier pivoting mechanism. 
           [0016]      FIG. 4  is a top plan view of the brush head of  FIG. 1  showing the location of the bristle tuft groups on the outer or second outer bristle tuft rows on the bristle carrier and arranged on both sides of the brush head shaft. The width of the bristle tuft groups on the outer row can be determined by the pivoting angle. The width may be narrower but should exceed more than 20% the width of the arch of the pivoting angle measured on the radius determined by the centre of the pivoting and the location of the bristle group on the bristle carrier. 
           [0017]      FIG. 5  is a front view of the brush head in  FIG. 1  showing the outwardly inclined bristle tuft groups on both sides of the bristle carrier. As the bristle tuft groups are inclined into position where access to teeth neck and gum is optimized, these areas are more efficiently cleaned in brushing operation. This results in a decreased accumulation of plaque on the tooth neck. 
           [0018]      FIG. 6  is a perspective front view of the brush head in  FIG. 1  showing the elongation of the bristles in the bristle tuft groups according to an example of the invention. 
           [0019]      FIGS. 7A-C  are perspective front views showing example variations of bristle tufts arrangement in the brush head of  FIG. 1 . 
           [0020]      FIGS. 8A  &amp; B show two examples of manufacturing methods according to the present invention. For example, in  FIG. 8A  the bristle tuft groups are inserted on the outer row of the bristle carrier and are bent outwardly by a fixture. The position can then be secured by wedges glued in place between the bristle tuft groups and the next bristle row.  FIG. 8B  shows another example method of inserting the bristle tufts into blind bores in the bristle carrier. The bores can be drilled in any desired angle. 
           [0021]      FIGS. 9A-D  are examples of brush cleaning elements. 
           [0022]      FIG. 10  shows a top plan view of a brush head. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0023]    The present invention generally relates to a replacement toothbrush head for electric toothbrushes. According to certain embodiments, the toothbrush head may comprise, or consist of, some or all of the following elements; a driving electromagnet assembled in a toothbrush head  1 , a brush head shaft  3 , a brush head housing  2  comprising a bottom portion with a pivoting axle  5  in the centre and a movable bristle carrier  4  for carrying tooth cleaning bristles, a moveable bristle carrier  4  connected and/or coupled to a central pivoting axle  5 ; a brush head bottom member fixedly connected to and/or coupled to a brush head shaft  3  and said brush head shaft  3  fixedly connected and/or coupled to said brush head housing  2 ; a brush head shaft  3  including a mechanical linkage assembly  6 ; a mechanical linkage assembly  6  connected to a movable bristle carrier  4  and an electromagnetic drive such that the bristle carrier  4  can pivot around a brush head pivoting axle  5  when the electromagnet is actuated. 
         [0024]    The bristle carrier  4  can have blind-end bores in which a plurality of tooth cleaning bristles or other tooth cleaning elements can be fixedly attached. Examples of several types of tooth cleaning elements configured in to bristle tufts can be seen, for example, in  FIGS. 9A-9D . The bristles and/or other tooth cleaning elements can be arranged into bristle tufts  7  &amp;  7   a  each containing a plurality of the bristles or other tooth cleaning elements. 
         [0025]      FIGS. 1 and 1  a show an example of a toothbrush head  1  according to the present invention. The toothbrush head  1  comprises a brush head housing  2 , a brush head shaft  3  and a moveable bristle carrier  4 . The moveable bristle carrier  4  has an outer contour  10  which is shown as a circle. The outer contour  10  of the bristle carrier may be elliptical or any other desired symmetric or asymmetric shape. 
         [0026]    The bristle carrier  4  further comprises a brush assembly  7   b  having a first set of bristle tufts  7  and a second set of bristle tufts  7   a.    FIG. 2  shows another angle of the unit of  FIG. 1 . the first set of bristle tufts  7  are seen in two rows of bristle tuft groups  9  and  9   a,  and the second set of bristle tufts  7   a  are shown in four rows in-between groups  9  and  9   a.    
         [0027]      FIG. 3  shows a cutaway of the unit  1  of  FIG. 1  along the cut lines A-A. The toothbrush head unit  1  is shown comprising a mechanical linkage assembly  6  within the brush head shaft  3 . The mechanical linkage assembly  6  is coupled to a pivoting axel  5  within the brush head housing  2 . The brush head housing  2  may be an integral portion of the brush head shaft or they may be separate portions connected together during a manufacturing process. The pivoting axel  5  is connected long a central axis  17  to the movable bristle carrier  4 . 
         [0028]      FIG. 4  shows an arrangement of the bristle tufts on the bristle carrier with reference to the longitudinal axis  15  of the brush head shaft  3  and a median line  13  of the bristle carrier. 
         [0029]    The bristle tuft groups ( 9 ,  9   a ) in the outermost rows, which may be or may be considered as a single circular outer row, are disposed at a pivoting angle  14 . The pivoting angle is shown as a displacement with regards to the median line  13 . The pivoting angle  14  can be between 5° and 45° and is preferably between 20° and 30° off of a median line  13  of the bristle carrier  4 . 
         [0030]    Additionally, the median line  13  of the bristle carrier  4 , which should divide the bristle carrier in to two equal hemispheres, can be disposed ±0 to 45°, for example 25°, from perpendicular from the longitudinal axis  15  of the brush head shaft  3 . However, the median line  13  is preferably perpendicular to the longitudinal axis  15 . 
         [0031]      FIG. 5  shows an example of a brush head housing  2  wherein the bristle tuft groups  9 ,  9   a  are disposed in an outward leaning angle  16  compared to a central axis  17  of the pivoting axle  5 . The outward leaning angle  16  can be between 5° and 45° and preferably between 15° and 25°. 
         [0032]      FIG. 6  shows the offset bristle length difference  18  between the lengths of the first and second set bristle tuft groups  7  and  7   a.  While first bristle tufts  7  can have some degree of variance, they can be, or can substantially be the same length. Similarly, while the second bristle tufts  7   a  can have some degree of variance, as shown in  FIG. 6  for example, they can be, or can substantially be the same length. However, the first bristle tufts  7  should be longer than the second bristle tufts  7   a.    
         [0033]    The difference in length between the two groups can be considered as the true difference, i.e. when stood parallel to each other, or as an offset bristle length difference  18  as shown in  FIG. 6  which takes in to consideration the disposition of the first bristle tufts  7  from the second bristle tufts  7   a  of the outward leaning angle  16 . Either the true difference or the offset bristle length difference  18  between the first and second bristle tufts should be greater than 50%, i.e. the first bristle tufts  7  should be more than 1.5 times longer than the second bristle tufts  7   a.  Preferably, the offset bristle length difference should be 100-200%. 
         [0034]      FIGS. 7A-7C  shows several examples of bristle patterns on the bristle carrier  4 . As can be seen, various arrangements according to the present invention can be implemented. 
         [0035]    The bristles or other cleaning elements rows can follow a circular outer edge of the bristle carrier. Additionally, the bristle tufts in the outer, or second outer row or rows can be arranged in groups containing one or more tufts of first and/or second bristle tufts  7 ,  7   a . The bristle tuft groups  9  and  9   a  can form a semi arch with the length of the arch determined by the size of the pivoting angle. 
         [0036]    Additionally, it is possible to arrange the first bristle tufts  7  in the outer or second outer row, advantageously in sectional groups covering each 10% to 40% of the total perimeter length of the row. Each of the sectional groups containing one or a plurality of individual bristle or other cleaning element tufts. Each bristle or other tooth cleaning element section formed by the bristle tufts can be located on the bristle carrier opposite to another similar section on the other side of the longitudinal axis of the brush head shaft. 
         [0037]    Brushing efficiency is improved by having the tooth cleaning tuft groups in the outer or second outer row and arranged in an outward leaning angle so that the tufts are better able to reach the tooth neck area where most of plaque is deposited. 
         [0038]    It should be understood from the design, and also proven in practice, that the shorter the inner row bristle tufts are in comparison with the outer row bristle tufts, the more the brushing efficiency is directed towards the outer rows. As bristle tufts in the outer rows, in accordance with this innovation, have been inclined outwards, they hence can better reach the tooth neck area and gum pockets where the plaque has been deposited during the day. The brushing efficiently of the outer row would reach the maximum if the inner bristles are cut all the way down. This would however reduce the overall brushing efficiency so an optimum between the overall brushing and tooth neck area brushing efficiencies is sought by adjusting the length of the middle row bristles accordingly. 
         [0039]    Furthermore, there is described herein methods of manufacturing a toothbrush head in accordance with the present invention. According to such methods, a bristle carrier is manufactured having a multiplicity of bristles fastened thereto. The manufacturing process is simplified as it is possible to use existing tuft setting equipment for setting the bristle tufts. 
         [0040]    The bristle or other tooth cleaning element tufts are fastened to the bristle carrier for example either by using a metal plate anchor, by the same plastic material used for injection molding of the bristle carrier or any other method known by the art. Additionally, as shown in  FIG. 8   b , the bristles can be affixed in blind ended bores  21  drilled, or otherwise manufactured in to the bristle carrier  4  at a desired outwardly leaning angle  16 . 
         [0041]    It is to be understood that the embodiments of the invention disclosed are not limited to the particular structures, process steps, or materials disclosed herein, but are extended to equivalents thereof as would be recognized by those ordinarily skilled in the relevant arts. For example,  FIG. 10  shows an arrangement of bristles in an alternative orientation with regards to the shaft. It should also be understood that terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting. 
         [0042]    Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. 
         [0043]    As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary. In addition, various embodiments and examples of the present invention may be referred to herein along with alternatives for the various components thereof. It is understood that such embodiments, examples, and alternatives are not to be construed as de facto equivalents of one another, but are to be considered as separate and autonomous representations of the present invention. 
         [0044]    Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of lengths, widths, shapes, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention. 
         [0045]    While the forgoing examples are illustrative of the principles of the present invention in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and without departing from the principles and concepts of the invention. Accordingly, it is not intended that the invention be limited, except as by the claims set forth below.
     1 —Toothbrush head     2 —Brush head housing     3 —Brush head shaft     4 —Moveable bristle carrier     5 —Pivoting axle     6 —Mechanical linkage assembly     7 —First bristle tufts     7   a —Second bristle tufts     7   b —Brush assembly     9  &amp;  9   a —Bristle tuft groups     10 —Outer contour of the bristle carrier     13 —Median line of the bristle carrier     14 —Pivoting angle     15 —Longitudinal axis of the brush head shaft     16 —Outward leaning angle     17 —Central axis of the pivoting axel     18 —Offset bristle length difference     19 —Wedge     21 —Blind ended bores