Abstract:
An electric toothbrush ( 10, 100 ) is disclosed as including an electric motor ( 22, 122 ), a shaft ( 56, 156 ) engaged with a brush head ( 18 ), and a coupling mechanism operatively associated with the motor ( 22, 122 ) and the shaft ( 56, 156 ) for coupling with the motor ( 22, 122 ) to drive the shaft ( 56, 156 ) to swivel about a longitudinal axis of the shaft ( 56, 156 ), the coupling mechanism including a reciprocating block ( 34, 134 ) reciprocable along a straight line perpendicular to the longitudinal axis of the shaft ( 56, 156 ).

Description:
[0001]    This is a Continuation-In-Part of U.S. patent application Ser. No. 10/202,678 filed on Jul. 25 2002. 
     
    
     
         [0002]    This invention relates to an electric toothbrush, and in particular, such a toothbrush with a shaft adapted to be engaged with a brush head, and to swivel about its longitudinal axis.  
         BACKGROUND OF THE INVENTION  
         [0003]    There are many different constructions of electric toothbrushes. In such existing electric toothbrushes, a coupling mechanism is arranged between an electric motor and a shaft to which a brush head is attached, so that the output of an output spindle of the motor is transmitted to cause the shaft, and thus the brush head, to perform a brushing movement. Conventional coupling mechanisms are usually rather complicated and, given the relatively small size of an electric toothbrush, costly to produce.  
           [0004]    It is thus an object of the present invention to provide a new electric toothbrush with a coupling mechanism of a relatively simple construction, and is thus less costly to manufacture, or at least to provide a useful alternative to the public.  
         SUMMARY OF THE INVENTION  
         [0005]    According to the present invention, there is provided an electric toothbrush including an electric motor, a shaft member adapted to be engaged with a brush member, and a coupling mechanism operatively associated with said motor and said shaft member for coupling with said motor to drive said shaft member to swivel substantially about a longitudinal axis of said shaft member, wherein said coupling mechanism includes a movable member adapted to reciprocate along a substantially straight line which is substantially perpendicular to said longitudinal axis of said shaft member. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]    Preferred embodiments of an electric toothbrush according to the present invention will now be described, by way of examples only, and by reference to the accompanying drawings, in which:  
         [0007]    [0007]FIG. 1 is a front perspective view of an electric toothbrush according to the present invention;  
         [0008]    [0008]FIG. 2A is an enlarged exploded view of a first coupling mechanism suitable for use in the electric toothbrush shown in FIG. 1;  
         [0009]    [0009]FIG. 2B is a further enlarged exploded view of the coupling mechanism shown in FIG. 2A with the top-open container removed;  
         [0010]    [0010]FIG. 3A is a top view of the reciprocating block of the coupling mechanism shown in FIG. 2A;  
         [0011]    [0011]FIG. 3B is a front view of the reciprocating block shown in FIG. 3A;  
         [0012]    [0012]FIG. 3C is a bottom view of the reciprocating block shown in FIG. 3A;  
         [0013]    [0013]FIG. 3D is a side view of the reciprocating block shown in FIG. 3A;  
         [0014]    [0014]FIGS. 4A to  4 D are top views of the relative positions of the components of the coupling mechanism shown in FIG. 2A during various stages of the operation of the electric toothbrush shown in FIG. 1;  
         [0015]    [0015]FIG. 5A is an enlarged exploded view of a second coupling mechanism of suitable for use in the electric toothbrush shown in FIG. 1;  
         [0016]    [0016]FIG. 5B is a further enlarged exploded view of the coupling mechanism shown in FIG. 5A with the top-open container removed;  
         [0017]    [0017]FIG. 6A is a top view of the reciprocating block of the coupling mechanism shown in FIG. 5A;  
         [0018]    [0018]FIG. 6B is a side view of the reciprocating block shown in FIG. 6A;  
         [0019]    [0019]FIG. 6C is a front view of the reciprocating block shown in FIG. 6A;  
         [0020]    [0020]FIG. 6D is a bottom view of the reciprocating block shown in FIG. 6A;  
         [0021]    [0021]FIG. 7A is a top view of the swiveling block of the coupling mechanism shown in FIG. 5A;  
         [0022]    [0022]FIG. 7B is a side view of the swiveling block shown in FIG. 7A;  
         [0023]    [0023]FIG. 7C is a front view of the swiveling block shown in FIG. 7A;  
         [0024]    [0024]FIG. 7D is a bottom view of the swiveling block shown in FIG. 7A; and  
         [0025]    [0025]FIGS. 8A to  8 D are top views of the relative positions of the components of the coupling mechanism shown in FIG. 5A during various stages of the operation of the coupling mechanism shown in FIG. 5A. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0026]    [0026]FIG. 1 shows a front perspective view of an electric toothbrush according to a first embodiment of the present invention, generally designated as  10 . The toothbrush  10  includes an elongate handle  12  including a slidable button  14  operable to activate or deactivate the toothbrush  10 , as desired. Extending from an upper end of the handle  12  is a hollow elongate tube  16 , which leads to a brush head  18 , with a number of bristles  20  for brushing. The brush head  18  is fixedly engaged with a shaft (to be discussed below) which extends through the hollow elongate tube  16  into the interior of the toothbrush  10  for engagement with a first coupling mechanism, to be discussed below. Housed in the handle  12  is a motor (to be discussed below) powerable by one or more dry batteries (not shown) also contained in the handle  12 , or by an a.c. source.  
         [0027]    As shown in FIGS. 2A and 2B, an electric motor  22  housed in the handle  12  has an output spindle  24  which is fixedly fitted in an opening  26  of a revolving disc  28 . Extending from and fixedly secured with an upper surface  30  of the disc  28  is a pin  32 , which is received within an underside of a reciprocating block  34 , in a manner to be discussed below. It can be seen that, when the motor  22  is activated, rotation of the spindle  24  will cause the disc  28  and the accompanying pin  32  to revolve about the longitudinal axis of the spindle  24 .  
         [0028]    The reciprocating block  34  has, on its upper part, a channel  36  running along its length. The channel  36  is generally circular in shape, but with a flat bottom surface  38 . A correspondingly sized and shaped generally cylindrical rod  40  is received within the channel  36 . As the rod  40  also has a partly flat outer surface which abuts the flat bottom surface  38  of the channel  36 , the block  34  may only slide relative to the rod  40  along its length, with no relative swivelling or rotational movement. Although it is preferred to provide a flat bottom surface  38  in the channel  36  and a partly flat outer surface on the rod  40  which complement with each other, both flat surfaces may be dispensed with without significantly affecting the performance of the coupling mechanism.  
         [0029]    As shown in FIG. 2A, the block  34  is hung and received within a cavity  42  of a top-open container  44  by the rod  40  for reciprocating movement. In particular, the container  44  has two ears  46  positioned on the upper edge of two opposite side walls  48 . Each ear  46  has a hole  50  shaped and sized as the channel  36  of the reciprocating block  34 . Thus, when the block  34  is placed in the cavity  42  of the container  44 , the rod  40  may be inserted through a hole  50  of one ear  46 , then through the channel  36 , and subsequently through the hole  50  of another ear  46 . By way of such an arrangement, the block  34  is hung within the cavity  42  for reciprocating movement relative to the rod  40 , and along an axis parallel to the length of the rod  40 .  
         [0030]    On each lateral side of the block  34  is a row of gear teeth  52   a ,  56   b . The gear teeth  52   b  are in mesh with a gear  54  fixed to a shaft  56 . The brush head  18  is fixedly engaged with an upper end of the shaft  56  for simultaneous movement. By way of such an arrangement, reciprocating movement of the block  34  will set the shaft  56 , and thus the brush head  18 , into swivelling movement about its longitudinal axis. It can also be seen that the longitudinal axis of the shaft  56  is perpendicular to the rod  40 .  
         [0031]    [0031]FIGS. 3A to  3 D show various views of the reciprocating block  34 . As can be seen more particularly in FIG. 3C, an elongate recess  58  is formed on an underside of the block  34  for receiving part of the pin  32  of the disc  28 . The recess  58  is of a width that is the same or slightly larger than the diameter of the pin  32 , to allow sliding movement of the pin  32  relative to the recess  58 . It can also be seen that the length of the recess  58  is perpendicular to the length of the block  34 .  
         [0032]    [0032]FIGS. 4A to  4 D show respective plan views of the relative position between the gear  54 , the block  34 , the rod  40  and the revolving disc  28  of the toothbrush  10 . It should be pointed out that the position of the longitudinal axis of the shaft  56 , and thus of the gear  54 , the longitudinal axis of the output spindle  24  of the motor  22 , and the rod  40  are fixed relative to one another.  
         [0033]    [0033]FIG. 4A shows the block  34  in the right-most position relative to the rod  40 . When the motor  22  is activated, the spindle  24  rotates so that the pin  32  of the disc  28  revolves around the longitudinal axis of the spindle  24  in the direction indicated by the arrow G, until the pin  32  reaches the position shown in FIG. 4B. As the pin  32  is confined within the recess  58  of the block  34 , and the movement of the block  34  is confined by the rod  40 , the block  34  will slide relative to the rod  40  in the direction indicated by the arrow H, thus causing the gear  54 , and the shaft  56  with which the gear  54  is secured, to rotate in the direction indicated by the arrow K. When the spindle  24  further rotates, the pin  32  will revolve around the spindle  24  in the direction indicated by the arrow J shown in FIG. 4B, until the pin  32  reaches the position shown in FIG. 4C. It can be seen that the block  34  has moved further relative to the rod  40  in the direction of the arrow H, and the gear  54  has rotated further in the direction indicated by the arrow K. In particular, in the position shown in FIG. 4C, the block  34  is in the left-most position relative to the rod  40 .  
         [0034]    When the pin  32  further revolves around the spindle  24  in the direction shown by the arrow M in FIG. 4C, the block  34  will start to move in the direction shown by the arrow P in FIG.  4 C, which is opposite to the direction indicated by the arrow H in FIG. 4A, and the gear  54  will start to rotate about its own longitudinal axis in the direction indicated by the arrow Q, which is opposite to the direction indicated by the arrow K in FIG. 4A. Further rotation of the pin  32  relative to the spindle  24  in the direction of the arrow M shown in FIG. 4C will bring the pin  32  to the position shown in FIG. 4D, thus causing the block  34  to slide relative to the rod  40  further in the direction indicated by the arrow P, which in turn causes the gear  54  to rotate further about its longitudinal axis in the direction indicated by the arrow Q. Further rotation of the spindle  24  in the same direction will bring the pin  32  back to the position shown in FIG. 4A, thus completing a cycle of rotational movement.  
         [0035]    It can be seen that, by way of the coupling mechanism discussed above, upon activation of the motor  22 , the spindle  24  will rotate, thus causing the block  34  to reciprocate along the rod  40 , which in turn causes the gear  54 , and the brush head  18  fixed thereto, to swivel back and forth about the longitudinal axis of the shaft  56 .  
         [0036]    A second coupling mechanism suitable for use in an electric toothbrush according to the present invention is shown in FIGS. 5A and 5B. An electric motor  122  housed inside the toothbrush has an output spindle  124  which is fixedly fitted with a revolving block  128  for simultaneous rotational movement. Extending from and fixed with an upper surface  130  of the block  128  is a pin  132 , which is received within an underside of a reciprocating block  134 , in a manner to be discussed below. When the motor  122  is activated, rotation of the spindle  124  will cause the revolving block  128  and the accompanying pin  132  to revolve about the longitudinal axis of the spindle  124 .  
         [0037]    The reciprocating block  134  has a generally circular channel  136  running through its body. A correspondingly sized and shaped generally cylindrical rod  140  is received within the channel  136 , for allowing the block  134  to slide relative to the rod  140 .  
         [0038]    The block  134  is hung and received within a cavity  142  of a top-open container  144  by the rod  140  for reciprocating movement. In particular, the container  144  has two ears  146  positioned on the upper edge of two opposite side walls  148 . Each ear  146  has a hole  150  shaped and sized as the channel  136  of the reciprocating block  134 . Thus, when the block  134  is placed in the cavity  142  of the container  144 , the rod  140  may be inserted through a hole  150  of one ear  146 , then through the channel  136 , and subsequently through the hole  150  of another ear  146 . By way of such an arrangement, the block  134  is hung within the cavity  142  for reciprocating movement relative to, and along an axis parallel to the length of, the rod  140 .  
         [0039]    A pin  102  is received within a hole  106  of the block  134  for simultaneous reciprocating movement with the block  134 . The pin  102  extends upward from the reciprocating block  134 , and its top end is received within an underside of a swiveling block  104  for relative movement, in a manner to be discussed below. A shaft  156  is fixedly received within a hole  108  of the swiveling block  104  for simultaneous swiveling movement. A brush head (not shown) is fixedly engaged with an upper end of the shaft  156  for simultaneous movement. By way of such an arrangement, reciprocating movement of the block  134  will set the shaft  156 , and thus the brush head, into swiveling movement about its longitudinal axis. It can also be seen that the longitudinal axis of the shaft  156  is perpendicular to the rod  140 .  
         [0040]    [0040]FIGS. 6A to  6 D show various views of the reciprocating block  134 . As can be seen more particularly in FIG. 6D, an elongate recess  158  is formed on an underside of the block  134  for receiving part of the pin  132  of the revolving block  128 . The recess  158  is of a width that is the same or slightly larger than the diameter of the pin  132 , to allow sliding movement of the pin  132  relative to the recess  158 .  
         [0041]    [0041]FIGS. 7A to  7 D show various views of the swiveling block  104 . As can be seen more clearly in FIG. 7D, an elongate recess  110  is formed on an underside of the block  104  for receiving the upper end of the pin  102  extending from the reciprocating block  134 . The recess  110  is of a width that is the same or slightly larger than the diameter of the pin  102 , to allow sliding movement of the pin relative to the recess  110 . It can be seen that the recess  110  is parallel to the length of the swiveling block  104 .  
         [0042]    [0042]FIGS. 8A to  8 D show respective plan views of the relative position between the swiveling block  104 , the reciprocating block  134 , the rod  140  and the revolving block  128  (shown in dashed line) of the toothbrush. It should be pointed out that the position of the longitudinal axis of the shaft  156 , the longitudinal axis of the output spindle  124  of the motor  122 , and the rod  140  are fixed relative to one another.  
         [0043]    [0043]FIG. 8A shows the block  134  in the right-most position relative to the rod  140 . When the motor  122  is activated, the spindle  124  rotates so that the pin  132  of the block  128  revolves about the longitudinal axis of the spindle  124  in the direction indicated by the arrow G′, until the pin  132  reaches the position shown in FIG. 8B. As the pin  132  is confined within the recess  158  of the reciprocating block  134 , and the movement of the block  134  is confined by the rod  140 , the block  134  will slide relative to the rod  140  in the direction indicated by the arrow H′. The movement of the block  134  will cause the pin  102  to also move in the direction indicated by the arrow H′. Because of the confinement of the pin  102  in the recess  110  of the swiveling block  104 , the swiveling block  104 , and thus the shaft  156  with which it is secured, will be caused to swivel in the direction indicated by the arrow K′ about the axis of the shaft  156 .  
         [0044]    When the spindle  124  further rotates, the pin  132  will revolve around the spindle  124  in the direction indicated by the arrow J′ shown in FIG. 8B, until the pin  132  reaches the position shown in FIG. 8C. It can be seen that the block  134  has moved further relative to the rod  140  in the direction of the arrow H′, and the swiveling block  104  has rotated further in the direction indicated by the arrow K′. In particular, in the position shown in FIG. 8C, the block  134  is in the left-most position relative to the rod  140 .  
         [0045]    When the pin  132  further revolves around the spindle  124  in the direction shown by the arrow M′ in FIG. 8C, the block  134  will start to move in the direction shown by the arrow P′ in FIG. 8C, which is opposite to the direction indicated by the arrow H′ in FIG. 8A, and the swiveling block  104  will start to rotate about the longitudinal axis of the shaft  156  in the direction indicated by the arrow Q′, which is opposite to the direction indicated by the arrow K′ in FIG. 8A. Further rotation of the pin  132  relative to the spindle  124  in the direction of the arrow M′ shown in FIG. 8C will bring the pin  132  to the position shown in FIG. 8D, thus causing the reciprocating block  134  to slide relative to the rod  140  further in the direction indicated by the arrow P′, which in turn causes the swiveling block  104  to rotate further about the longitudinal axis of the shaft  156  in the direction indicated by the arrow Q′. Further rotation of the spindle  124  in the same direction will bring the pin  132  back to the position shown in FIG. 8A, thus completing a cycle of rotational movement.  
         [0046]    It can be seen that, by way of the coupling mechanism discussed above, upon activation of the motor  122 , the spindle  124  will rotate, thus causing the block  134  to reciprocate along the rod  140 , which in turn causes the swiveling block  104 , and the brush head fixed thereto, to swivel back and forth about the longitudinal axis of the shaft  156 .  
         [0047]    It should be understood that the above only illustrates examples whereby the present invention may be carried out, and that various modifications and/or alterations may be made thereto without departing from the spirit of the invention.  
         [0048]    It should also be understood that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any appropriate sub-combinations.