Abstract:
A toothbrush comprising a toothpaste dispenser that is removably connectable to a head, wherein when connected the toothpaste dispenser can dispense toothpaste from a dispensing aperture, through a passage formed in a shaft of the head and out through at least one aperture formed in a brush portion of the head. As the head is removably connected to the dispenser it is possible for a user to replace either the head or dispenser when needed. For example, a dispenser can be changed when it is empty. Alternatively, a head can be replaced when a different user wants to use the toothbrush when a head is too worn or when it a user desires to use a different shape or hardness head.

Description:
FIELD OF INVENTION 
       [0001]    The present invention relates to oral hygiene and provides an improved toothbrush that can dispense toothpaste or gel through a removable and interchangeable head. 
       BACKGROUND 
       [0002]    People brush their teeth using a toothbrush and a toothpaste, gel or other similar product. Typically they will use a simple handheld toothbrush onto the head of which they will place a suitable amount of toothpaste or gel dispensed either from a tube or a mechanical dispenser. As an alternative to a simple toothbrush, some people use electric toothbrushes. Electric toothbrushes generally have head portions that can be removably connected to a base portion wherein the base portion includes a battery and a motor which serves to oscillate and/or rotate and/or reciprocate an attached head when in use. The heads are replaceable to enable multiple users to use a single base portion and to allow a user to replace worn out head portions without the need to replace the much more expensive base portion. 
         [0003]    There have been attempts to combine toothpaste or gel dispensers with toothbrushes. This has been done for reasons of convenience. In particular, it would no longer be necessary to have separate toothpaste and toothbrush in order to brush one&#39;s teeth. This might be particularly advantageous when travelling. However, none of these attempts have produced a commercially viable product. In light of this there is a need for an improved combined toothpaste or gel dispenser and toothbrush. Any such device should be robust, practical and commercially viable. 
       SUMMARY OF INVENTION 
       [0004]    This is a toothbrush comprising a toothpaste dispenser that is removably connectable to a head, wherein when connected the toothpaste dispenser can dispense toothpaste from a dispensing aperture, through a passage formed in a shaft of the head and out through at least one aperture formed in a brush portion of the head. As the head is removably connected to the dispenser it is possible for a user to replace either the head or dispenser when needed. For example, a dispenser can be changed when it is empty. Alternatively, a head can be replaced when a different user wants to use the toothbrush when a head is too worn or when it a user desires to use a different shape or hardness head. 
         [0005]    In one embodiment, the present invention provides a toothbrush comprising: 
         [0006]    a toothpaste dispenser having a dispensing aperture located within a connector; and 
         [0007]    a head having a connecting portion at a first end, a brush portion and a shaft formed between the first end and the second end; wherein a passage for transport of toothpaste from the connecting portion to the brush portion is formed through the shaft, the passage having an opening at the connecting portion at a first end and being connected to at least one aperture formed in the brush portion at a second end; 
         [0008]    wherein the head is removably connectable to the dispenser and when connected, the connecting portion of the head is connected to the connector of the toothpaste dispenser and toothpaste may be dispensed from the dispensing aperture of the dispenser, through the passage, to the brush portion of the head; and 
         [0009]    the connector of the toothpaste dispenser and the connecting portion of the head cooperate to form a removable snap-fit connection and the connector and connecting portion are substantially oval in shape such that they can not rotate relative to one another when they are removably connected. 
         [0010]    Further features and advantages of the present invention will be apparent from the preferred embodiments that are shown in the drawings and are discussed below. 
     
    
     
       DRAWINGS 
         [0011]      FIG. 1  is a toothbrush; 
           [0012]      FIG. 2  is a cutaway diagram of the toothbrush of  FIG. 1 ; 
           [0013]      FIG. 3  is an exploded diagram of the toothbrush of  FIGS. 1 and 2 ; 
           [0014]      FIG. 4  is a cross-section of an upper cover of a toothpaste dispenser of the toothbrush of  FIGS. 1 to 3 ; 
           [0015]      FIG. 5  is a button of the toothbrush of  FIGS. 1 to 4 ; 
           [0016]      FIG. 6  is a cross-section of an upper portion of a toothpaste dispenser of the toothbrush of  FIGS. 1 to 5  including the upper cover of  FIG. 4  and the button of  FIG. 5 ; 
           [0017]      FIG. 7  is a cross-section of an upper cover of a toothpaste dispenser of a toothbrush according to an embodiment of the invention; 
           [0018]      FIG. 8  is a button of the toothbrush of the embodiment of the invention; 
           [0019]      FIG. 9  is a cross-section of an upper portion of a toothpaste dispenser of the toothbrush of the embodiment of the invention including the upper cover of  FIG. 7  and the button of  FIG. 8 ; 
           [0020]      FIG. 10  is a cross-section of a connecting portion of a head and a connector of a toothpaste dispenser according to an embodiment of the present invention wherein the head and the dispenser are not connected; 
           [0021]      FIG. 10   a  shows detail of the connector of  FIG. 10 ; 
           [0022]      FIG. 11  is a cross-section of a connecting portion of a head and a connector of a toothpaste dispenser according to the embodiment of  FIG. 10  wherein the head and the dispenser are connected; 
           [0023]      FIG. 12  is a cross-section of a connecting portion of a head and a connector of a toothpaste dispenser, wherein the head and the dispenser are not connected; 
           [0024]      FIG. 12   a  shows detail of the connector of  FIG. 12 ; 
           [0025]      FIG. 13  is a cross-section of a connecting portion of a head and a connector of a toothpaste dispenser according to the embodiment of  FIG. 12  wherein the head and the dispenser are connected; and 
           [0026]      FIGS. 14 to 19  show six alternative embodiments of the second end of a head according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]    It is to be noted that the term “toothpaste” used throughout this specification is intended to encompass any toothpaste, gel or similar product that might be dispensed from a dispenser and used with a toothbrush to clean one&#39;s teeth. Unless otherwise specified, none of the embodiments of the current invention are limited to any specific toothpaste or gel and it is to be understood that the skilled person would be immediately able to understand which toothpastes, gels or similar products are suitable for use with any given embodiment of the invention. 
         [0028]    The present invention is advantageous over previous toothbrushes that incorporated a toothpaste dispenser as it combines a removable head with a toothpaste dispenser. This allows more than one user to use the same toothbrush as each user may have their own disposable head that they simply attach to the toothpaste dispenser when they wish to use the toothbrush. Furthermore, having a removable head allows the toothpaste dispenser to be easily changed when it is empty without the need to change the head at the same time. This is advantageous as a toothbrush head may not necessarily be ready for replacement at the same time as the toothpaste dispenser becomes empty. Additionally, the toothbrush of the present invention dispenses toothpaste directly through the head. This can be significantly advantageous as it allows toothpaste only to be dispensed where it is actually used and may also allow additional toothpaste to be dispensed during use of the brush. 
         [0029]    The connecting portion of the head and the connector of the toothpaste dispenser form a removable connection when the head is connected to the toothpaste dispenser. The removable connection must be robust enough that the toothbrush can be used in a substantially conventional manner without the head becoming unintentionally detached from the dispenser. However, the head must be able to be easily removed from the dispenser when the user desires to do so. 
         [0030]    The connector of the toothpaste dispenser and the connecting portion of the head cooperate to form a removable snap-fit connection. That is the connector of the toothpaste dispenser and the connecting portion of the head are shaped and formed such that it is possible to push one into the other until a resilient member in one of the connector and the connecting portion engages a cooperative aperture or groove in the other of the connector and connecting portion thereby forming a relatively strong but removable connection. 
         [0031]    The connector and connecting portion are shaped such that they cannot rotate relative to one another when they are removably connected. In particular, the connection is not rotatable and substantially circular. Instead, the connector of the toothpaste dispenser and the connecting portion of the head are substantially oval in shape. 
         [0032]    In order to make the snap-fit connection it may be preferable that the connection is double-walled, rather than single-walled. That is, it may be preferable that one of the connector of the toothpaste dispenser and the connecting portion of the head comprises an inner wall surrounding and extending coaxially outwards from an end of the dispensing aperture or an end of the passage and a cooperative outer wall spaced from the inner wall and extending coaxially outwards from an end of the dispensing aperture or an end of the passage; and the other of the connector of the toothpaste dispenser and the connecting portion of the head comprises cooperatively formed apertures for receiving the inner wall and the outer wall when the head is removably connected to the dispenser. Having a double-walled snap-fit connection is advantageous as the removable connection may be subject to significant stress when the toothbrush is being used. A double-walled snap-fit connection is much more likely to be able to withstand such stress than a single-walled snap-fit connection. 
         [0033]    The brush portion of the head may have either a single aperture connected to the passage or a plurality of apertures connected to the passage. In some embodiments of the invention a single aperture may be preferred due to simplicity of design. However, it is generally envisaged that is preferable that the brush portion of the head will have a plurality of apertures connected to the passage. This is because a plurality of apertures can allow toothpaste to be distributed to all parts of the brush portion and that distribution can be much more even than would be possible with a single aperture. 
         [0034]    If the brush portion has a plurality of apertures the apertures may all be substantially the same size and shape. Alternatively, each of the plurality of apertures may be sized and/or shaped such that, when in use, substantially the same amount of toothpaste is dispensed from each aperture. It is anticipated that the skilled person will be readily able to determine a suitable size and shape for each aperture in order to meet this requirement. For example, apertures that are a further distance from the toothpaste dispenser may be larger than apertures that are closer to the toothpaste dispenser. The size and shape of each aperture may be dependent on the distance from the toothpaste dispenser and/or their position in the brush portion of the head. 
         [0035]    In some embodiments of the invention which comprise a plurality of apertures in the brush portion of the head it may be preferable that the apertures are positioned in a single row, which extends along the direction in which the passage extends. This construction may be preferred as it is simpler than alternative constructions. In particular, it can allow a relatively narrow and straight passage to be used. 
         [0036]    Alternatively, it may be preferable that the plurality of apertures are positioned in two or more rows, each extending along the direction in which the passage extends or in any other pattern on the brush portion of the head. Such constructions may be preferred as they may provide a more even distribution of toothpaste over the brush portion of the head when the toothbrush is in use. 
         [0037]    The, or each, at least one aperture will extend from the passage to an outer surface of the brush portion and may have any shape that allows toothpaste to pass therethrough. For example, it may be preferable that the, or each, aperture is tubular. This may be preferred as it is a simple shape that is easily formed. Alternatively, the, or each, aperture may be frustoconical. This may be preferred as it may provide more even distribution of toothpaste than a tubular aperture and may be less likely to become blocked with toothpaste in between uses of the toothbrush. A frustoconical aperture may be oriented with either its wider radius substantially at the outer surface of the brush portion or at the passage. The choice of aperture shape will depend upon considerations such as the even distribution of dispensed toothpaste, the potential blocking of the apertures by toothpaste between uses of the toothbrush and aesthetic considerations. 
         [0038]    Advantageously, the dispenser of the toothbrush may be substantially any type of dispenser that could easily be held by a user and used as a toothbrush handle when the toothbrush is in use. In such embodiments the head and the passage will be relatively short and the user will hold the dispenser to operate the toothbrush. However, it is to be understood that it is possible for the head and the passage to be relatively longer and that a user may hold the head portion when using the toothbrush. In advantageous embodiments of the invention the head portion is relatively short, the dispenser is held by a user when the toothbrush is in use and the dispenser is a conventional plunger-type dispenser. 
         [0039]    The dispenser comprises a button for activating the dispensing of toothpaste from the dispenser. This may be particularly preferable if the dispenser is a plunger-type dispenser. It is preferable that the dispenser is substantially cylindrical and the button and the dispensing aperture are located at a first end of the dispenser. A cylindrical dispenser may be preferred as it can result in a toothbrush that has substantially the same form as a conventional electronic toothbrush and, as a result, users will be comfortable with using the resulting toothbrush. Positioning the button at the same end of a tubular dispenser as the dispensing aperture may be advantageous as it may be a more ergonomic and intuitive position for such a button than any other position. Furthermore, positioning a button on an end of a tubular dispenser, rather than one a side, will reduce the likelihood of the button being accidentally pressed by a user when they are gripping the dispenser in order to use the toothbrush. 
         [0040]    If the button and dispensing aperture are positioned on an end of a tubular dispenser it may be preferable that the dispensing aperture and the button are positioned to extend in a direction parallel to an axis of the dispenser. Additionally or alternatively, the dispensing aperture may be positioned to extend in a direction parallel to an axis of the dispenser and the button may be positioned such that when the head is connected to the dispenser the button is positioned substantially behind the head or substantially in front of the head. It is currently considered advantageous to position a button either directly behind the head or directly in front of the head when the head is removably connected to the dispenser. However, the button may be located in any other position that is considered appropriate by a designer of a toothbrush according to the present invention. 
         [0041]    In order to form a toothbrush that is easy to use and has a similar shape to current toothbrushes, it may be preferable that the dispenser is substantially cylindrical, the aperture is located at a first end of the dispenser and, when connected to the dispenser, the head extends in a direction substantially parallel to an axis of the dispenser. However, it is to be appreciated that, when connected to the dispenser, the head may extend in any other direction relative to the dispenser that a designer considers appropriate. 
         [0042]    If, when removably connected to a tubular dispenser, the head extends in a direction parallel to the axis of the dispenser it may be advantageous that the head extends substantially along the axis of the dispenser. This may be preferred as it may provide the most resilient construction of the toothbrush. However, in alternative embodiments of the invention it may be preferable for the head to extend parallel to the axis of a tubular dispenser but be offset from that axis for reasons of aesthetics or ergonomics. In particular, offsetting the head from the axis may better allow the positioning of the button on an end of a dispenser. 
         [0043]    A toothbrush  1  is shown in  FIGS. 1 to 3 . The toothbrush  1  comprises a head  2  and a toothpaste dispenser  3 . The head  2  and the dispenser  3  can be removably connected, as shown in  FIGS. 1 and 2 , by means of a snap-fit connection  4 . The snap-fit connection  4  is formed by connecting portion  5  formed at a first end of the head  2  and a connector  6  formed at an upper end of the dispenser  3 . 
         [0044]    The dispenser  3  is a substantially conventional tubular plunger-type dispenser and, as such, comprises a button  7  for dispensing toothpaste, a plunger  8 , a container  9 , a piston  10 , a stopper  16  and a lower cover  11 . The dispenser  3  also comprises a tube  12  that extends from an opening in the plunger  8 , through an upper cover  19 , to the connector  6  such that when the dispenser is operated toothpaste is dispensed through the connector. It is to be understood that the skilled person will readily understand the operation of a plunger-type dispenser and therefore its operation will not be discussed further. 
         [0045]    The dispenser  3  is substantially tubular and the button  7  and the connector  6  are located at an upper end of the dispenser  3 . They both extend in a direction parallel to the axis of the dispenser  3  but are offset from that axis. 
         [0046]    The head comprises a central passage  17  that extends from the connecting portion  5  to a brush portion  13 . For clarity, the brush portion  13  is shown without bristles. However, it is to be understood that in reality all of the brush portions illustrated in the Figures would have bristles. The brush portion  13  has a plurality of apertures  14  located at a brushing face  15 . The apertures  14  extend from the passage  17  through the brushing face  15  such that when toothpaste is dispensed from the dispenser  3  through the passage  12  the toothpaste will emerge through the apertures  14  at the brushing face  15  of the head  2 . 
         [0047]    The toothbrush  1  is operated in the following manner. When it is desired to use the toothbrush  1  a head  2  is removably connected to the dispenser  3  using the snap-fit connection  4 . Toothpaste is then dispensed from the dispenser  3  by pressing the button  7 . When toothpaste begins to be dispensed through the apertures  14  at the brush portion  13  of the head  2  the user will then brush their teeth, holding the container  9  of the dispenser  3 . If the user desires additional toothpaste at any time when brushing their teeth they may simply press the button  7  on the dispenser without the need to stop brushing their teeth. If a different user wishes to use the toothbrush  1  they may do so using their own head  2 . To do this they would first remove the head  2  that the previous user had been using and attach their own head  2  to the toothbrush using the connecting portion  5  of the head  2 . Similarly, if the dispenser  3  runs out of toothpaste it can be simply removed from a head  2  and either replaced with a full dispenser  3  or refilled and then reconnected to the head. 
         [0048]    The upper cover  19  of the dispenser  3  of the toothbrush  1  of  FIGS. 1 to 3  is shown in  FIG. 4 , the button  7  is shown in  FIG. 5  and an upper portion of the dispenser  3  including the upper cover  19  and the button  7  is shown in  FIG. 6 . Together  FIGS. 4 to 6  show how a substantially conventional plunger-type dispenser  3  has been modified to arrive at the dispenser  3 . In particular, the button  7  is formed such that it can be offset from the axis of the dispenser  3  but that pressing the button  7  downwards still presses the plunger  8  of the dispenser downwards and results in toothpaste being dispensed. Similarly, the Figures show how the passage  12  is formed such that toothpaste can pass out of the dispenser to the connector  6  when the button is pressed. 
         [0049]    The upper cover  19  of the dispenser  3  of an embodiment of the invention is shown in  FIG. 7 , a button  7  of the embodiment is shown in  FIG. 8  and the upper portion of a dispenser  3  of the embodiment including the upper cover  19  and the button  7  is shown in  FIG. 9 . The toothbrush of  FIGS. 7 to 9  is substantially the same as the toothbrush of  FIGS. 1 to 6  the only differences being the form and mounting of the button  7  and the direction in which the button  7  is pressed to dispense toothpaste. Otherwise, all the features of the toothbrush of  FIGS. 7 to 9  are identical to those of the toothbrush of  FIGS. 1 to 6 . Therefore, the same reference numerals have been used to indicate the same features of each embodiment. 
         [0050]    In contrast with the toothbrush of  FIGS. 1 to 6 , the button  7  of the toothbrush of  FIGS. 7 to 9  is mounted normal to the axis of the dispenser  3 . That is, the button  7  is substantially horizontally mounted and must be pressed inwards in order for the dispenser  13  to dispense toothpaste. To allow the button  7  to function it has a cam surface  20  that is shaped such that it provides a downwards force on the plunger  8  when the button  7  is pressed inwards. Providing a horizontally mounted button  7  may be preferred as some users may find it more ergonomic and easier to use. 
         [0051]    A snap-fit connection  4  according to an embodiment of the present invention is shown in  FIGS. 10 ,  10   a  and  11 . The snap-fit connection  4  allows a head  2  to be removably connected to a toothpaste dispenser  3  such that the central passage  17  of the head is joined to the passage  12  of the dispenser  3  and that toothpaste may be dispensed through the passage  12  of the dispenser  3  into the central passage  17  of the head  2 . The snap-fit connection  4  is formed by a connecting portion  5  of the head  2  and a connector  6  of the dispenser. 
         [0052]    The snap-fit connection of  FIGS. 10 ,  10   a  and  11  is double walled in order to provide added strength and resilience as compared to a conventional single walled snap-fit connection. In particular, the connector  6  of the dispenser  3  comprises an inner wall  23  surrounding and extending coaxially outwards from the passage  12  of the dispenser  3  and a cooperative outer wall  24  spaced at a constant distance from the inner wall  23  and also extending coaxially outwards from the central passage. The outer wall  24  includes a circumferential groove  25 . The connecting portion  5  of the head  2  also comprises an inner wall  21  and an outer wall  22  in substantially the same manner as the connector  6  of the dispenser. The inner wall  21  of the connecting portion  5  includes a circumferential ridge  26  that is cooperatively located to engage with the circumferential groove  25  when the connecting portion  5  is removably connected to the connector  6 . 
         [0053]    The inner walls  21 ,  23  and outer walls  22 ,  24  are sized and shaped such that when the head  2  is removably connected to the dispenser  3  the inner wall  23  of the connector  6  fits inside the inner wall  21  of the connecting portion  5 , the outer wall  24  of the connector  6  fits around the inner wall  21  of the connecting portion  5  and inside the outer wall  22  of the connecting portion  5  and the outer wall  22  of the connecting portion  6  fits around the outer wall  24  of the connector  6 , as shown in  FIG. 11 . The snap-fit connection is formed by the circumferential ridge  26  being located within the circumferential groove  25 . 
         [0054]    As can be seen in  FIG. 10   a , in order to prevent rotation of the head  2  relative to the dispenser  3 , the inner and outer walls  21 ,  22 ,  23  and  24  are not circular but are substantially oval in shape. This means that the head  2  can only be attached to the dispenser  3  when they are in the correct rotational alignment and once connected they cannot be rotated relative to one another, for example when the toothbrush  1  is in use. 
         [0055]    A bayonet mount that is outside the scope of the present invention is shown in  FIGS. 12 ,  12   a  and  13 . The bayonet mount operates in a substantially conventional manner. In the embodiment of the Figures the connecting portion  5  forms a male side of the mount and has two connecting pins  27  and the connector  6  forms the female side of the mount and has a matching L-shaped receptor slots  28 . In order to engage the connecting portion  5  with the connector  6  the pins  27  are aligned with the slots  28 , the head  2  is pushed down such that the pins  27  enter the slots  28  and the head is then rotated until the pins  27  reach the end of the slots. The end of each slot  28  and the radially outer end of each pin  27  is formed such that there is a friction fit between the pins  27  and the slot  28  when the pins  27  are positioned at the end of each slot. This prevents the connection  4  being accidentally unconnected when a user is brushing their teeth. In order to remove a head  2  from a dispenser  3  the above process is reversed. 
         [0056]    As the bayonet mount itself prevents relative rotation of a head  2  relative to a dispenser  3  when they are removably connected to one another and because it is necessary for the two portions of a bayonet mount to be circular, both the connector  6  and the connecting portion  5  are substantially circular. The circular connector  6  can be seen in  FIG. 12   a.    
         [0057]      FIGS. 14 to 19  show the upper part of six alternative embodiments of heads  2  of toothbrushes according to the present invention. As the heads  2  of the present invention are interchangeable any of the alternative heads  2  of  FIGS. 14 to 19  can be used with any dispenser that has a connector  6  that matches the connecting portion  5  of the head. It is to be noted that, for clarity,  FIGS. 14 to 19  show the heads  2  without bristles. Furthermore, only an upper part of each head  2  is shown and, as a result, the connector  6  of each head is not shown. 
         [0058]    A first head  2   a  is shown in  FIG. 14 . This head has three apertures  14 . The apertures  14  are equally spaced along a brushing face  15  of the head  2   a  and are aligned with the passage  17 . Each aperture  14  is tubular and has an axis that is substantially normal to an axis of the passage  17  and to the brushing face  15 . In order to allow equal paste dispensing through each aperture  14 , the apertures have different diameters. In particular, the aperture  14  closest to an upper end of the head  2   a  has the largest diameter and the aperture  14  closest to the connector  6  has the smallest diameter. 
         [0059]    A second head  2   b  is shown in  FIG. 15 . The head has six apertures  14 . The six apertures  14  are arranged in two lines of three. Each line of three apertures  14  are equally spaced along a brushing face  15  of the head  2   b  and are aligned with an edge of the passage  17 . Providing two rows of apertures  14 , rather than a single row, may be preferable in order to provide more even distribution of toothpaste through the bristles of the brush. In order to provide even paste dispensing, the diameter of each of the apertures  14  of each row of three apertures  14  is varied in the same manner as the apertures  14  of the head  2   a  of  FIG. 14 . Each aperture  14  is tubular. However, unlike the apertures  14  of  FIG. 14 , the apertures  14  of  FIG. 15  are angled away from a direction that is normal to the axis of the passage  17  to support more thorough dispensing through the bristles of the brush. It is to be understood that the specific angles shown in  FIG. 15  are an example only and the optimum angling of any specific aperture  14  would be able to be determined by a skilled person. 
         [0060]    A third head  2   c  is shown in  FIG. 16 . The third head  2   c  is substantially the same as the first head  2   a  except that each aperture  14  is frustoconical rather than tubular. The narrow end of each aperture  14  is positioned at the passage  17  and the wide end of each aperture  14  is positioned at the brushing face  15 . Having frustoconical apertures  14  may be advantageous as it may allow dried paste to be expelled from the apertures more easily. 
         [0061]    A fourth head  2   d  is shown in  FIG. 17 . The fourth head  2   d  is substantially the same as the first head  2   a  except that each of the apertures  14  is angled away from a direction that is normal to the axis of the passage  17  in the same manner as the apertures  14  of the second head  2   b . Angling the apertures  14  in this manner can provide improved paste dispensing. 
         [0062]    A fifth head  2   e  is shown in  FIG. 18 . The fifth head  2   e  has only a single aperture  14  that is positioned centrally in a small substantially circular brushing face  15 . The aperture  14  is tubular and is normal to the axis of the passage  17  in the same manner as the apertures  14  of the first head  2   a . Having a small brushing face  15  with a single aperture  14  may be advantageous as it can provide a toothbrush  1  that can access more areas of the mouth than a toothbrush using a larger head. 
         [0063]    A sixth head  2   f  is shown in  FIG. 19 . As with the fifth head  2   e , the sixth head  2   f  has only a single aperture  14  that is positioned centrally in a small substantially circular brushing face  15 . The aperture  14  is frustoconical and has an axis that is normal to the axis of the passage  17  in the same manner as the apertures  14  of the third head  2   c . This head  2   f  combines the advantages of the fifth head  2   e  and the third head  2   c.    
         [0064]    It is to be noted that any of the six heads  2   a ,  2   b ,  2   c ,  2   d ,  2   e ,  2   f  may be interchanged with one another by a user according to his needs and desires as appropriate. For example, a user may wish to use the second head  2   b  for the majority of their brushing and then switch to the sixth head  2   f  when a smaller head is required to reach less accessible areas.