Patent Publication Number: US-10758327-B2

Title: Electric toothbrush with rigidly connected grip portion and brush portion

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     This application claims the benefit of priority to Japanese Patent Application Serial No. 2016-051505, filed Mar. 15, 2016, the entirety of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     (1) Field of the Invention 
     The present invention relates to an electric toothbrush having a grip portion and a brush portion, and more particularly, to the structure of the electric toothbrush. 
     (2) Description of Related Art 
     The electric toothbrush in the market has the grip portion and the brush portion with an indicator located in the grip portion. Also, the electric toothbrush in the market has the brush portion angled or inclined with respect to the grip portion. Such an electric toothbrush is disclosed, for example, in US Patent Publication No. 2011-0056033 (corresponding to Japanese Patent Publication No. 2009-268828). 
     According to US Patent Publication No. 2011-0056033, the indicator is provided on only one side of the electric toothbrush where the bristle is provided, so that the user can view the indicator only when the electric toothbrush is held at a certain angle. It is difficult for the user to see the indicator when the electric toothbrush is held in sideways, particularly when the user is brushing the inside surface of the tooth. 
     Also, according to US Patent Publication No. 2011-0056033, since the brush portion is angled or inclined with respect to the grip portion, the tension or stress observed at a joint between the grip portion and brush portion will be relatively high, particularly when the user pushes the brush hard against the teeth. There is no detailed description in US Patent Publication No. 2011-0056033 on the structure of connection between the grip portion and the brush portion. 
     BRIEF SUMMARY OF THE INVENTION 
     (1) Problems to be Solved 
     The prior art electric toothbrush has such problem that the tension between the grip portion and the brush portion will be relatively high, as explained above. An object of the present invention is to provide an electric toothbrush which has a rigid connection between the grip portion and the brush portion. 
     (2) Means for Solving the Problems 
     According to the present invention, an electric toothbrush having a grip portion and a brush portion with an axis of the brush portion being angled or inclined a predetermined angle with respect to an axis of the grip portion, comprises: a stem accommodated in the brush portion, said stem having a cavity for installing a vibration generator, a first screw groove formed at a bottom of the stem, and a first engage member formed adjacent the first screw groove; a cylindrical body included in the grip portion and having a receiving opening; and a stem joint arrangement including a stem joint for connecting the brush portion and the grip portion, wherein said stem joint having an upper cylinder portion and a lower cylinder portion, with an axis of the upper cylinder portion being inclined a predetermined angle with respect to an axis of the lower cylinder portion, and wherein the upper cylinder portion is formed with a second screw groove, and a second engage member adjacent the second screw groove, whereby the lower cylinder portion is inserted in the receiving opening formed in the cylindrical body, and the first screw groove engages with the second screw groove in a screwing manner, and the first engage member engages with the second engage member. 
     According to an embodiment, the first screw groove is a male screw groove, and the second screw groove is a female screw groove. 
     According to an embodiment, the first engage member is a projection, and the second engage member is a recess. 
     According to an embodiment, the stem joint arrangement further includes a stem packing made of rubber and a rubber cover covering the lower cylinder portion. 
     According to an embodiment, the cylindrical body is formed with a plurality of blocks in the receiving opening, and the lower cylinder portion is formed with a plurality of indents which engage with the blocks. 
     According to the electric toothbrush of the present invention, since a stem joint having an upper cylinder portion and a lower cylinder portion inclined to each other is used, the grip portion and the brush portion will not be easily separated even when a tension or stress is applied therebetween. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a side view of an electric toothbrush according to an embodiment of the present invention. 
         FIG. 2  is an exploded view of the electric toothbrush shown in  FIG. 1 . 
         FIG. 3  is a perspective view of a circuit board shown in  FIG. 2 . 
         FIG. 4  is a perspective partial view of a chassis shown in  FIG. 2 . 
         FIG. 5A  is a side view of an illumination ring body shown in  FIG. 2 . 
         FIG. 5B  is a top plan of the illumination ring body shown in  FIG. 5A . 
         FIG. 6  is a cross-sectional view of the illumination ring body taken along line VI-VI shown in  FIG. 5B . 
         FIG. 7  is a cross-sectional partial view of the electric toothbrush shown in  FIG. 1 . 
         FIG. 8  is a cross-sectional partial view taken along line VIII-VIII shown in  FIG. 7 . 
         FIG. 9  is a cross-sectional partial view taken along line XI-XI shown in  FIG. 8 . 
         FIG. 10  is a side view of a stem joint shown in  FIG. 2 . 
         FIG. 11  is a cross-sectional view of the stem joint shown in  FIG. 10 . 
         FIG. 12  is a perspective view of the stem joint shown in  FIG. 11 . 
         FIG. 13  is an exploded view of the stem joint and the stem. 
         FIG. 14  is a side view of the stem joint and the stem in the connected condition. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG. 1 , an electric toothbrush  1  according to an embodiment of the present invention is shown. The electric toothbrush  1  has a grip portion  2  and a brush portion  4 . An axis X 4  of the brush portion  4  is angled or inclined a predetermined angle θ, such as for example but not limited to between about 6 and about 10 degrees, most preferably about 8 degrees, with respect to an axis X 2  of the grip portion  2  so that a bristle portion  4   a  of the brush portion  4  can be easily held against a user&#39;s tooth when the grip portion  2  is held by the user proximate the user&#39;s mouth. As will be discussed below, the axis X 4  and the axis X 2  can be considered to be defined by the upper cylinder portion  42   a  and the lower cylinder portion  42   b  of the stem joint  42 , respectively, in certain embodiments. 
     Referring to  FIG. 2 , an exploded view of the electric toothbrush  1  is shown. The grip portion  2  of the electric toothbrush  1  includes an elongated body cover  10 , a chassis  20 , a battery holder  16 , a motor support  62 , and an elongated circuit board  50 . An intermediate portion including an illumination ring body  30 , a stem joint arrangement  40 , and a top cover  12 , is positioned between and arranged to couple the grip portion  2  to the brush portion  4 . The electric toothbrush further includes a stem  80  that is connected to and extends from the intermediate portion. The stem  80  accommodates a DC motor  60  having a cylindrical body, and a vibration shaft  70 . A top rubber cover  14  is also provided as part of the intermediate portion. The brush portion  4  includes a replaceable brush  90 . A battery to be inserted in the battery holder  16  is a rechargeable battery or a dry cell battery. The replaceable brush  90  is detachably mounted on the stem  80 . The replaceable brush  90  covers the stem  80  completely or partially. 
     In the specification, the term “top” or “upper” refers to the side of the electric toothbrush  1  where the replaceable brush  90  is provided, and the term “bottom” or “lower” refers to the side where the battery holder  16  is provided, such as shown in  FIG. 1 . 
     The body cover  10  has an interior cavity, which may be for example, cylindrical, for accommodating the chassis  20 , battery holder  16  and circuit board  50 . The body cover  10  has a top side and a bottom side opened. The body cover  10  is capable of being gripped or grasped by a user. 
     As shown in  FIG. 3 , the circuit board  50  has an elongated board  52  and a light emitting element support plate which is a U-shaped plate  54  firmly connected to a top end of the elongated board  52 . The U-shaped plate  54  has two arms  54   a  and  54   b  extending perpendicularly from the top end of the elongated board  52 . Two light emitting elements, such as light-emitting diodes (LEDs)  56   a  and  56   b  are mounted on one arm  54   a , and another two LEDs  56   c  and  56   d  are mounted on other arm  54   b , so that four LEDs  56   a ,  56   b ,  56   c  and  56   d  are located, when viewed from the top, at four corners of a rectangle, or a square. While four LEDs  56   a ,  56   b ,  56   c  and  56   d  are shown and described here, more or fewer LEDs may be located on the plate  54 . Moreover, the LEDs may be discrete LED sources or they could include one or more flexible printed or organic LED substrates capable of illumination. Turning ON and OFF of the LEDs  56   a ,  56   b ,  56   c  and  56   d  are controlled by a controller mounted on the circuit board  50 . The controller includes a micro-processor and an acceleration sensor. The acceleration sensor is used for detecting the angle of the toothbrush held by a user. As shown in  FIG. 2 , a connector  58  extends through the center of the U-shaped plate  54  for electrical connection with the DC motor  60 . 
     Referring to  FIG. 4 , a top portion of chassis  20  is shown. Chassis  20  has a pair of fingers  22   a  and  22   b  for holding the elongated board  52 , a pair of shoulders  24   a  and  24   b , and a neck portion  26 . The neck portion  26  has a center hole in the direction of axis X 2 , with recesses  26   a  and  26   b  formed at opposite sides thereof. Through-holes  28  and  29  are formed, respectively, under the shoulders  24   a  and  24   b . The through-holes  28  and  29  have bottom surfaces  28   a  and  29   a , respectively, which are flattened for receiving thereon, respectively, the two arms  54   a  and  54   b  of the U-shaped plate  54 . 
     The two arms  54   a  and  54   b  of the U-shaped plate  54  are inserted in the through-holes  28  and  29 , respectively, as shown in  FIG. 2 , and the elongated board  52  is firmly held between the fingers  22   a  and  22   b . Also, the connector  58  extends through the center hole in the neck portion  26 . When the arms  54   a  and  54   b  of the U-shaped plate  54  are placed on bottom surfaces  28   a  and  29   a  of the through-holes  28  and  29 , the LEDs  56   a ,  56   b ,  56   c  and  56   d  on the two arms  54   a  and  54   b  face the top, i.e., in the direction of axis X 2 . 
     The through-holes  28  and  29  further have top slanted surfaces  28   b  and  29   b  which are for reflecting purposes and are angled about 45 degrees with respect to the direction of axis X 2  so that light rays emitted from the LEDs, particularly, from  56   a  and  56   c  reflect on the slanted surfaces  28   b  and  29   b , and direct outwardly in a radial or otherwise substantially perpendicular direction with respect to the axis X 2 . In  FIG. 4 , only two slanted surfaces  28   b  and  29   b  are shown, but there are two more slanted surfaces  28   c  and  29   c  on the other side in  FIG. 4 . The slanted surfaces  28   b ,  28   c ,  29   b  and  29   c  are angled about 45 degrees with respect to axis X 2  in radial direction, so that slanted surfaces  28   b ,  28   c ,  29   b  and  29   c  are arranged in a manner similar to an umbrella surface. Each of the slanted surfaces  28   b ,  28   c ,  29   b  and  29   c  is flat, but it may be curved. The light rays emitted from the LEDs  56   a ,  56   b ,  56   c  and  56   d  in the direction of axis X 2  are reflected on the slanted surfaces  28   b ,  28   c ,  29   b  and  29   c , and are further directed in the radial direction or otherwise substantially perpendicular with respect to the axis X 2 . 
     Referring to  FIGS. 5A and 6 , the illumination ring body  30  is shown which is made of a substantially transparent or translucent material, such as synthetic resin. The illumination ring body  30  has hollow cylindrical body  30   a  with an illumination ring  30   b  circumferentially surrounding the cylindrical body  30   a . The illumination ring  30   b  is an annular structure that protrudes from the outer surface of the illumination ring body  30 , thereby forming an annular flange. The illumination ring  30   b  is inclined or angled a predetermined angle θ, such as for example but not limited to between about 6 degrees and about 10 degrees, most preferably about 8 degrees, with respect to a plane perpendicular to the axis X 2 . The cylindrical body  30   a , which is a part of the grip portion  2 , has opposite ends opened, and has an internal plate  30   c  inside the cylindrical body  30   a  so as to provide a skirt wall  30   d  below the internal plate  30   c . The center of the internal plate  30   c  is formed with an opening  30   e  ( FIG. 5B ) in a shape of semi-circle to fittingly match the semi-circle cross-section of the neck portion  26  with recesses  26   a  and  26   b , as best shown in  FIG. 8 . Above the internal plate  30   c , the cylindrical body  30   a  has a receiving opening  30   i  for fittingly receiving a lower cylinder portion  42   b  of the stem joint  42  covered with a bottom rubber cover  46 , as will be described later. While the illumination ring body  30 , including the cylindrical body  30   a  and illumination ring  30   b , is shown and described as being cylindrical, one of skill in the art will recognize that other shapes and geometries are possible depending on the shape and design of the grip portion  2  of the electric toothbrush  1 . 
     As shown in  FIG. 5B , on the top surface of the internal plate  30   c , there are three blocks  30   f ,  30   g  and  30   h  formed at corners between the internal plate  30   c  and the cylindrical body  30   a.    
     On the outside of the illumination ring body  30 , a pair of projections  30   p  are provided, as shown in  FIG. 5A . 
     The chassis  20  provided with the circuit board  50  is inserted into the body cover  10  from the bottom opening, and held inside the body cover  10  at a position shown in  FIG. 4 , so that the top end of the chassis  20  stays a little below the top opening of the body cover  10 . 
     As shown in  FIGS. 7 and 8 , the illumination ring body  30  is mounted on the shoulders  24   a  and  24   b  of the chassis  20  such that neck portion  26  of the chassis  20  is fittingly inserted into the opening  30   e . At this position, the bottom surface of the internal plate  30   c  rests on the shoulders  24   a  and  24   b  of the chassis  20 , and the skirt wall  30   d  circumferentially surrounds, at least in part, the slanted surfaces  28   b ,  28   c ,  29   b  and  29   c . The outer surface of the illumination ring body  30  below the illumination ring  30   b  is fittingly inserted into the top opening of the body cover  10  such that the projections  30   p  on the illumination ring body  30  engage with complementary recesses (not shown) formed on the inside surface of the body cover  10  to couple the body cover  10  to the illumination ring body  30 . 
     As shown in  FIG. 9 , the light emitted from the LEDs, such as  56   a  and  56   b , reflects on the slanted surfaces  28   b  and  28   c , and direct toward the skirt wall  30   d , so that the light is optically transmitted within inside and throughout the illumination ring body  30 . Some of this light will be transmitted into the illumination ring  30   b  and exit an outer annular surface of the illumination ring  30   b  that forms a portion of the exposed outer surface of the electric toothbrush. 
     As shown in  FIG. 7 , a majority of the illumination ring body  30  is concealed such that the portion below the illumination ring  30   b  is concealed by body cover  10 , and the portion above the illumination ring  30   b  is concealed by top cover  12 . Body cover  10  and top cover  12  may both be substantially opaque and may be made from the same or different materials. In this embodiment, only the illumination ring  30   b  can be viewed directly from the outside of the electric toothbrush  1 . 
     The outside surface of the illumination ring body  30 , with the exception for the illumination ring  30   b , can be coated with a reflector paint so that light that has entered the illumination ring body  30  from the inside surface of the skirt wall  30   d  can be maintained within the illumination ring body  30  until said light can exit the illumination ring  30   b . Stated simply, the reflector paint will prevent and/or minimize leakage of light. Thus, light from the illumination ring  30   b  can be outputted with high intensity outside the electric toothbrush  1 . 
     Since the illumination ring  30   b  is provided in a viewable manner completely, i.e., 360 degrees, around the electric toothbrush  1  just above the grip portion  2 , it is possible for the user to view the lighting of the illumination ring  30   b  no matter which angle the electric toothbrush  1  is held. It should be noted, however, that while the illumination ring  30   b  is an annular continuous structure in the illustrated embodiment, in other embodiments the illumination ring  30   b  may be in the form of spaced-apart segments that collectively define a segmented ring structure. 
     The lighting of the illumination ring  30   b  can be effected in various occasions in various modes, as explained below. 
     The first occasion is when a bristle portion of the electric toothbrush  1  is held at about 45 degrees above or below the plane level so that the bristle touches the tooth pockets of the upper or lower tooth from the outside or inside the tooth. 
     The second occasion is when the electric toothbrush  1  is held at about 90 degrees above or below the plane level so that the bristle touches the occlusal surface of the molar or pre-molar tooth. 
     The third occasion is when the electric toothbrush  1  is held at about the plane level so that the bristle touches the front face or back face of the tooth perpendicularly. 
     Each of the above occasions can be detected by the acceleration sensor in a manner disclosed, for example, in U.S. Publication No. 2012/0251975 (corresponding to Japanese Publication No. JP2011-156204) or Japanese Publication JP2009-291316, which are herein incorporated by reference in its entirety. 
     The lighting mode can be changed with respect to different occasions. For example, a first lighting mode can be an ON and OFF mode such that the LEDs are turned ON when the above explained target angle is detected. 
     A second lighting mode can be a graduation variable mode such that the LEDs change the strength of the light (i.e., the intensity of the light) to glow brighter as the toothbrush angle reaches the target angle. 
     A third lighting mode can be a blinking mode such that the frequency of ON and OFF of the LEDs becomes higher as the toothbrush angle reaches the target angle. 
     In one embodiment, the lighting can be effected only in one of the three occasions explained above using any one of the three lighting modes. 
     Referring to  FIG. 2 , the stem joint arrangement  40  includes a stem joint  42 , a stem packing  44  and a bottom rubber cover  46 . 
     Referring to  FIGS. 10 and 11 , the stem joint  42  has an upper cylinder portion  42   a  and a lower cylinder portion  42   b . The upper cylinder portion  42   a  has its axis aligned with axis X 4 , and the lower cylinder portion  42   b  has its axis aligned with axis X 2 . 
     The upper cylinder portion  42   a  has an inside surface formed with female screw groove  42   c . The top surface of the upper cylinder portion  42   a  is formed with a slanted projection  42   d  and a stopper projection  42   e . The slanted projection  42   d  has one side formed with a slanted wall and the other side formed with an upright wall. The stopper projection  42   e  has opposite sides formed with upright walls. A receiving recess  42   f , which is a second engage member (a first engage member will be described later), is formed adjacent the screw groove  42   c , such as between the projections  42   d  and  42   e , particularly between the upright wall of the slanted projection  42   a  and the upright wall of the stopper projection  42   e.    
     Referring to  FIG. 12 , the lower cylinder portion  42   b  has a recessed ring portion  42   g  and three legs  42   h ,  42   i  and  42   j . As shown, legs  42   i  and  42   j  are mirror images of one another and together are positioned diametrically opposite the leg  42   h . An indent  42   k  is formed between legs  42   h  and  42   i . An indent  42   l  is formed between legs  42   h  and  42   j . An indent  42   m  is formed between legs  42   i  and  42   j.    
     The stem packing  44  as shown in  FIGS. 2 and 7 , made of rubber or a like material, is fittingly inserted in the recessed ring portion  42   g  (see  FIGS. 10-12 ). The bottom rubber cover  46  as shown in  FIGS. 2 and 7  is fittingly mounted on the lower cylinder portion  42   b  covering each of the legs  42   h ,  42   i  and  42   j  separately (see  FIGS. 10-12 ). Accordingly, indents  42   k ,  42   l  and  42   m  appear on the outside of the bottom rubber cover  46 . 
     Next, the connection between the lower cylinder portion  42   b  and the illumination ring body  30  is explained. 
     With reference to  FIGS. 2 and 7 , the lower cylinder portion  42   b  mounted with the bottom rubber cover  46  is fittingly inserted in the receiving opening  30   i  of the hollow cylindrical body  30   a  of the illumination ring body  30  such that indents  42   k ,  42   l  and  42   m  existing on the outside of the bottom rubber cover  46  fittingly receive three blocks  30   g ,  30   h  and  30   f , respectively. Accordingly, the lower cylinder portion  42   b  is prevented from being freely rotated in the hollow cylindrical body  30   a.    
     As shown in  FIG. 7 , stem  80  has an elongated cavity  86  for receiving a vibration generator including the vibration shaft  70  and the DC motor  60 . The vibration shaft  70  includes an extension shaft  72  made, for example, of synthetic resin, such as POM (polyoxymethylene), and an eccentric shaft  73  which may be, for example, made of metal. The extension shaft  72  of the vibration shaft  70  includes a collar portion  74  provided close to a bottom end, a resilient shaft portion  75  and a connecting portion  76  which are integrally formed by synthetic resin. The bottom end face of the extension shaft  72  is formed with a recess to be engaged with a shaft of the DC motor  60 . DC motor  60  has two wires extending from a bottom face thereof for electric connection with the circuit board  50  through connector  58 . The vibration shaft  70  and the DC motor  60  are placed in the elongated cavity  86  and held in the cavity by the motor support  62 . 
     The eccentric shaft  73  of the vibration shaft  70  includes an eccentric portion  77  and an axial shaft portion  78 . The bottom end of the eccentric portion  77  is firmly connected to the connecting portion  76  by molding and the upper end of the eccentric portion  77  is provided with the axial shaft portion  78 . 
     When the vibration shaft  70  rotates about its axis by the DC motor  60 , the eccentric portion  77  generates a high frequency vibration which is transmitted to the stem  80  and to the brush  90 . The resilient shaft portion  75  has a flexibility to receive the high frequency vibration of the eccentric portion  77 . 
     Stem  80  is also formed by synthetic resin, such as for example, POM. A recessed hole  87  is formed at the end of the elongated cavity  86 . The recessed hole  87  slidably receives the axial shaft portion  78 . The elongated cavity  86  accommodates therein the vibration shaft  70  and the DC motor  60 . The vibration shaft  70  is freely rotated in the elongated cavity  86 . The recessed hole  87  serves as a bearing for freely holding the axial shaft portion  78 . The vibration shaft  70  freely rotates inside the elongated cavity  86  even under high frequency vibration. 
     Since the recessed hole  87  serves as the bearing, it is not necessary to provide a separate bearing arrangement for rotatably holding the axial shaft portion  78 . 
     Referring to  FIG. 13 , a lower end portion of the stem  80  is shown in detail. Stem  80  includes a collar  82 , and a male screw groove  84  below the collar  82 . A projection  85 , which is a first engage member, is formed adjacent the screw groove  84 , such as immediately under the collar  82 , i.e., near the end of the screw groove  84 . 
     Stem  80  is firmly connected to the stem joint  42  such that the male screw groove  84  of stem  80  is driven into the female screw groove  42   c  of the stem joint  42 , as the stem  80  rotates about its axis X 4 . When the stem  80  rotates a predetermined number of turns, the projection  85 , which is the first engage member, slides over the slanted wall of the slanted projection  42   d , and falls into the receiving recess  42   f , which is the second engage member, as best shown in  FIG. 14 . At this point, stem  80  is prevented from a further rotation in either direction and is retained at a desired and predetermined rotated position from the viewpoint of balance as well as to ensure that the brush  90  is properly oriented relative to the grip portion  2  when attached. The projection  85 , which is the first engage member, and the receiving recess  42   f , which is the second engage member, can be formed in opposite relationship, or any other engaging or retaining arrangement can be used. The male and female screw grooves  84  and  42   c  can be provided in opposite relationship. 
     As shown in  FIGS. 2 and 7 , the top rubber cover  14  is mounted on the stem  80  such that the bottom face of the top rubber cover  14  abuts against the upper surface of the collar  82 . Then, the top cover  12  is mounted on the stem  80  such that the bottom face of the top cover  12  abuts against the upper surface of the illumination ring  30   b.    
     According to an embodiment, suitable bonding agent is used in at least in one or more of the following instances: (a) between elongated body cover  10  and illumination ring body  30 , (b) between illumination ring body  30  and stem joint  42 , and (c) between stem joint  42  and stem  80 . 
     According to the above described embodiment, the slanted surfaces  28   b ,  28   c ,  29   b  and  29   c  are provided in the chassis  20 , but can be provided at any other places, such as at the bottom surface of the internal plate  30   c  of the illumination ring body  30 . In still another embodiment, the slanted surfaces may be omitted and the light emitting elements  56   a - d  will be arranged to emit light directly into the illumination ring body  30 . Additionally, while the illumination ring  30   b  is illustrated as being between the grip portion  2  and the brush portion  4 , and more specifically the grip portion  2  and the intermediate portion, in other embodiment, the illumination ring  30   b  may be located at a lower position and entirely within the grip portion  4  or entirely within the intermediate portion. 
     INDUSTRIAL APPLICABILITY 
     The electric toothbrush can be used for oral health care. 
     KEYS TO THE REFERENCE NUMBERS 
       1  . . . electric toothbrush,  2  . . . grip portion,  4  . . . brush portion,  10  . . . body cover,  12  . . . top cover,  14  . . . top rubber cover,  16  . . . battery holder,  20  . . . chassis,  22   a ,  22   b  . . . fingers,  24   a ,  24   b  . . . shoulders,  26  . . . neck portion,  26   a ,  26   b  . . . recesses,  28 ,  29  . . . through-holes,  28   b ,  28   c ,  29   b ,  29   c  . . . slanted surfaces,  30  . . . illumination ring body,  30   a  . . . cylindrical body,  30   b  . . . illumination ring,  30   c  . . . internal plate,  30   d  . . . skirt wall,  30   e  . . . opening,  30   f ,  30   g ,  30   h  . . . blocks,  40  . . . stem joint arrangement,  42  . . . stem joint,  42   c  . . . female screw groove,  42   d  . . . slanted projection,  42   e  . . . stopper projection,  42   h ,  42   i ,  42   j  . . . legs,  42   k ,  42   l ,  42   m  . . . indents,  44  . . . stem packing,  46  . . . bottom rubber cover,  50  . . . elongated circuit board,  52  . . . elongated board,  54  . . . U-shaped plate,  56   a ,  56   b ,  56   c ,  56   d  . . . LEDs,  60  . . . DC motor,  62  . . . motor support,  70  . . . vibration shaft,  80  . . . stem,  90  . . . replaceable brush