Abstract:
A run channel in an automobile door includes a U-shaped run channel body. An inner lip extends from a bottom end portion of an inner wall of the run channel body towards a peak portion. An upper lip is formed above the inner lip and extends from an intermediate portion of the inner wall to the peak portion. When a door glass abuts on the inner lip, the door glass presses the inner lip towards the inner wall to cause a distal end portion of the inner lip to press on the upper lip, whereby a reaction force of the upper lip is applied to the distal end portion of the inner lip. The inner lip in turn produces a reaction force slowing upward movement of the door glass, causing its upper edge to slowly abut on the peak portion of the run channel, thus reducing a glass striking sound.

Description:
FIELD OF THE INVENTION 
   The present invention relates generally to a run channel structure and, in particular, to a run channel structure including a run channel body for receiving an edge portion of a door glass, and inner and outer lips provided to the run channel body. 
   BACKGROUND OF THE INVENTION 
   Door glass ascent/descent systems include window regulators for moving door glasses of vehicles upward or downward. The door glass is moved upward by the window regulator for closing a window of a vehicular door. When the door glass is moved upward and then an upper edge of the door glass hits a run channel, the door glass is prevented from moving further upward. At this time, a load exceeding a threshold level is applied to the window regulator. Such an excessive load is detected to thereby stop an operation of an electric motor with the result that the door glass stops at a closed position (i.e., at an uppermost position). 
   The above run channel is attached to a window sash of a front side door, as disclosed in, for example, JP-A-2003-72383. 
   The disclosed run channel has a U-shaped cross-sectional configuration formed by an inner wall, an outer wall and a peak portion. Inner and outer lips extend from the inner and outer walls for sealing engagement with inner and outer surfaces of the door glass, respectively. 
   As for the run channel, a window regulator raises the door glass and thereby presses an upper edge of the door glass against the peak portion of the run channel. With the upper edge of the door glass thus pressed against the peak portion, the door glass is not raised any more and a load exceeding a threshold level is applied to the window regulator. Such an excessive load is detected to thereby stop an operation of an electric motor with the result that the door glass stops at a closed position (i.e., an uppermost position). 
   As for the run channel, a problem arises that the window regulator raises and strikes the upper edge of the door glass onto the peak portion of the run channel at a predetermined speed whereupon an unpleasant strike sound is produced. 
   There has been a demand for a run channel arranged to reduce a strike sound of the door glass when the door glass moves to the closed position. 
   SUMMARY OF THE INVENTION 
   According to one aspect of the present invention, there is provided a run channel structure for guiding a door glass, comprising: a run channel body of generally U-shaped cross-section, the run channel body including an inner wall, an outer wall and a peak portion interconnecting top end portions of the inner and outer walls; an inner lip extending from a bottom end portion of the inner wall towards the peak portion; an outer lip extending from a bottom end portion of the outer wall towards the peak portion; an upper lip disposed above the inner lip and extending from an intermediate portion of the inner wall to the peak portion; and wherein, when the door glass abuts on the inner lip, the door glass presses the inner lip towards the inner wall to cause a distal end portion of the inner lip to press the upper lip. 
   When the door glass abuts on the inner lip, the door glass presses the inner lip towards the inner wall to thereby cause the distal end portion of the inner lip to press the upper lip. By the distal end portion of the inner lip thus pressing the upper lip, a reaction force of the upper lip is applied to the distal end portion of the inner lip to thereby make relatively large a reaction force of the inner lip to be applied to the door glass. By virtue of such a relatively large reaction force of the inner lip, an ascent speed of the door glass is satisfactorily reduced. Thus, an upper edge of the door glass relatively slowly abuts on the peak portion of the run channel structure while a reduced glass strike sound of the door glass is produced. The term “glass strike sound” as used herein means a sound produced when the upper edge portion of the door glass abuts on the peak portion of the run channel structure. 
   Preferably, the upper lip, the inner wall and the peak portion jointly define a hollow cross-sectional portion of generally triangular configuration. Namely, the upper lip is one side of the hollow cross-sectional portion of the generally triangular configuration with opposite ends of the upper lip supported. With this arrangement, a relatively large reaction force of the upper lip is securely produced when the distal end portion of the inner lip presses the upper lip. Such a relatively large reaction force of the upper lip is applied to the distal end portion of the inner lip to thereby cause the inner lip to produce a sufficient reaction force to be applied to the door glass. The application of the reaction force of the inner lip to the door glass satisfactorily reduces the ascent speed of the door glass with the result that the upper edge portion of the door glass relatively slowly abuts on the peak portion of the run channel structure. 
   Desirably, after the distal end portion of the inner lip presses the upper lip, the upper edge portion of the door glass abuts on the upper lip. Accordingly, it becomes possible to reduce the ascent speed of the door glass through the two steps, thereby causing the upper edge portion of the door glass to relatively slowly abut on the peak portion of the run channel structure. In addition, since the upper lip forms the one side of the hollow cross-sectional portion of the generally triangular configuration, an internal pressure within the hollow cross-sectional portion increases when the distal end portion of the inner lip presses the upper lip. This enables the upper lip to act as a cushion more effectively for producing a relatively large reaction force. Therefore, the ascent speed of the door glass is further satisfactorily reduced by the upper lip when the door glass abuts on the upper lip, with the result that the upper edge of the door glass relatively slowly abuts on the peak portion of the run channel structure. 
   Preferably, the hollow cross-sectional portion has an air releasing hole through which an inner space of the hollow cross-sectional portion communicates with the air. Thus, the internal pressure within the hollow cross-sectional portion can be easily adjusted and hence the reaction force of the upper lip and the reaction force of the inner lip to be applied to the door glass can be adjusted. This enables the satisfactory adjustment of the ascent speed of the door glass, such that the upper edge of the door glass abuts on the peak portion of the run channel structure at a preferable speed. 
   Preferably, the inner lip is formed to provide a greater size than the outer lip so as to facilitate an adjustment of a reaction force of the inner lip to be applied to the door glass when the door glass abuts on the inner lip. Thus, the inner lip can be relatively easily varied in configuration for easy adjustment of the reaction force of the inner lip to be applied to the door glass. By virtue of the inner lip, the ascent speed of the door glass can be satisfactorily adjusted, such that the upper edge of the door glass abuts on the peak portion of the run channel structure at a preferable speed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A certain preferred embodiment of the present invention will hereinafter be described in detail, by way of example only, with reference to the accompanying drawings, in which: 
       FIG. 1  is a side elevation view of a vehicle including a run channel structure according to the present invention; 
       FIG. 2  is a cross-sectional view taken along line  2 - 2  of  FIG. 1 ; 
       FIG. 3  is a view showing in cross-section the run channel structure and a door glass released from the run channel structure; 
       FIG. 4  is the view of  FIG. 3  with the door glass inserted into the run channel structure; 
       FIG. 5A  through  FIG. 5C  are views showing the door glass being raised towards the run channel structure according to the present invention; 
       FIG. 6A  through  FIG. 6C  are views showing how the door glass is inserted into the run channel structure according to the present invention; and 
       FIG. 7A  through  FIG. 7C  are views showing how a door glass is inserted into a run channel structure in a comparative example. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A vehicle  10  shown in  FIG. 1  includes a vehicle body  11  equipped with left and right front sash doors  12 ,  13  and left and right rear sash door  14 ,  15 . The vehicle body  11  has a roof  16  disposed over the left and right front sash doors  12 ,  13  and the left and right rear sash doors  14 ,  15 . 
   The right front sash door  13  includes a door body  17 , a sash body  18  provided on an upper part of the door body  17 , and a run channel structure  20  (see  FIG. 2 ) provided in the sash body  18 . The right front sash door  13  also includes a door glass  21 . 
   It is to be noted that the left and right front sash doors  12 ,  13  have the same structure and are symmetrically disposed while the left and right rear sash doors  14 ,  15  have the same structure and are symmetrically disposed. 
     FIG. 2  shows the right front sash door  13  in a closed position. 
   The sash body  18  of the right front sash door  13  is equipped with a weatherstrip  22  and the run channel structure  20 . The vehicle body  11  has a door opening part  23  provided therein for accommodating the sash body  18 . The door opening part  23  has an edge portion  24  to which a vehicle body side weatherstrip  25  is attached. 
   The weatherstrip  22  is attached to an outer peripheral wall  28  of the sash body  18  by means of a clip  29 . 
   When the right front sash door  13  is in the closed position, that is, when the sash body  18  is accommodated in the door opening part  23 , an inner wall portion  27  of the sash body  18  contacts the vehicle body side weatherstrip  25  while the weatherstrip  22  contacts the door opening part  23 . The weatherstrip  22  and the vehicle body side weatherstrip  25  thus arranged seal a gap between the door opening part  23  of the vehicle body  11  and the sash body  18 . 
   The run channel structure  20  is attached to the inside of the sash body  18 . When the door glass  21  slides in a direction of an arrow (an up-and-down direction), the run channel structure  20  guides the door glass  21  and is in a sealing engagement with the door glass  21 . 
     FIG. 3  shows the run channel structure with the door glass released therefrom. 
   The run channel structure  20  shown in  FIG. 3  is an elastic member made from an elastic material such as rubber and soft resin. The run channel structure  20  includes a run channel body  31 , an inner lip  36  and an outer lip  38 . The run channel body  31  is of U-shaped cross-section formed by an inner wall  32  provided on an interior side of the vehicle body  11  ( FIG. 1 ), an outer wall  33  provided on an exterior side of the vehicle body  11 , and a peak portion  34  interconnecting a top end portion  32   a  of the inner wall  32  and a top end portion  33   a  of the outer wall  33 . The inner lip  36  extends from a bottom end portion  32   b  of the inner wall  32  towards an outer end portion  34   a  of the peak portion  34 . The outer lip  38  extends from a bottom end portion  33   b  of the outer wall  33  towards an inner end portion  34   b  of the peak portion  34 . 
   When an upper edge portion  21   a  of the door glass  21  is inserted into the run channel body  31 , the inner lip  36  and the outer lip  38  guide the door glass  21  while being in a sealing engagement with the door glass  21 . 
   The run channel structure  20  also includes a lip  41  extending from the bottom end portion  32   b  of the inner wall  32  inward of the vehicle body  11  with a fitting portion  42  formed at the bottom end portion  32   b  of the inner wall  32 . The inner wall  32  has a hook-shaped projecting portion  43  disposed above the fitting portion  42 . The outer wall  33  has upper and lower locking projection portions  44 ,  45  provided at the top and bottom end portions  33   a ,  33   b  thereof. The peak portion  34  has inner and outer lips  46 ,  47  provided at the inner and outer end portions  34   b ,  34   a  thereof, respectively. 
   The fitting portion  42  is fitted with an inner wall lower end portion  51  of the sash body  18 . The hook-shaped projecting portion  43  is interlocked with an inner wall projecting portion  52  of the sash body  18 . The upper locking projection portion  44  is interlocked with an outer wall step portion  53  of the sash body  18 . The lower locking projection portion  45  is interlocked with an outer wall lower end portion  54  of the sash body  18 . 
   The inner and outer lips  46 ,  47  are pressed against a portion  56  of the sash body  18  which faces to the peak portion  34 . Such a portion  56  facing to the peak portion  34  is hereinafter referred to as “sash peak portion  56 ”. 
   The run channel structure  20  includes an upper lip  58  extending obliquely outwardly of the vehicle body  11  from an intermediate portion  32   c  of the inner wall  32  and reaching the outer end portion  34   a  of the peak portion  34 . The upper lip  58  is disposed above the inner lip  36  such that, when the door glass  21  abuts on the inner lip  36 , the door glass  21  presses the inner lip  36  towards the inner wall  32  to thereby cause a projection  61   a  (a tip end) provided at a distal end portion  61  of the inner lip  36  to press the upper lip  58 . 
   The upper lip  58  has an upper end portion  58   a  connected to the peak portion  34  and a lower end portion  58   b  connected to the intermediate portion  32   c  of the inner wall  32 , with the upper lip  58 , an upper portion  32   d  of the inner wall  32  and the peak portion  34  jointly defining a hollow cross-sectional portion  62  of generally triangular configuration. The upper lip  58  is convexly curved outwardly of the hollow cross-sectional portion  62 . 
   The reason why the hollow cross-sectional portion  62  is defined by the upper lip  58 , the upper portion  32   d  of the inner wall  32  and the peak portion  34  will be set forth later. 
   The peak portion  34  constituting one part of the hollow cross-sectional portion  62  has an air releasing hole  63  provided therein. By virtue of the air releasing hole  63  provided in the peak portion  34 , an inner space  64  of the hollow cross-sectional portion  62  communicates with the air. 
   The reason why the air releasing hole  63  is provided in the hollow cross-sectional portion  62  will be set forth later. 
     FIG. 4  shows the run channel structure with the edge portion of the door glass inserted thereinto. 
   The door glass  21  has an inner surface pressing the distal end portion  61  of the inner lip  36  of the run channel structure  20 . The door glass  21  has an outer surface pressing the outer lip  38 . The upper edge portion  21   a  of the door glass  21  abuts on the upper lip  58  of the run channel structure  20 . With this arrangement, the door glass  21  is held in the closed position. 
   By the door glass  21  pressing the distal end portion  61  of the inner lip  36 , the projection  61   a  provided at the distal end portion  61  of the inner lip  36  presses the upper lip  58 . 
   By the abutment of the upper edge portion  21   a  of the door glass  21  on the upper lip  58 , the upper lip  58  is deformed inwardly of the hollow cross-sectional portion  62  into a concave curve configuration to thereby reduce a volume of the inner space  64  of the generally triangular hollow cross-sectional portion  62 . 
   Additionally, by the abutment of the upper edge portion  21   a  of the door glass  21  on the upper lip  58 , the peak portion  34  of the run channel structure  20  abuts on the sash peak portion  56 . 
   The inner lip  36  is formed to provide a larger size than the outer lip  38 . More specifically, the inner lip  36  has a proximal portion  36   a  having a width W 1  set to be greater than a width W 2  of a proximal portion  38   a  of the outer lip  38 . The inner lip  36  has a thickness T 1  set to be greater than a thickness T 2  of the outer lip  38 . The inner lip  36  has a length L 1  set to be greater than a length L 2  of the outer lip  38 . 
   The width W 1  of the proximal portion  36   a , the thickness T 1  and the length L 1  are properly adjustable such that a reaction force to be exerted by the inner lip  36  on the door glass  21  when the door glass  21  abuts on the inner lip  36  is easy to adjust 
   Operation of the run channel structure according to the present invention will be discussed with reference to  FIG. 5A  through  FIG. 7C . 
     FIG. 5A  through  FIG. 5C  show an instance in which the door glass is raised towards the run channel structure. 
   In  FIG. 5A , an electric motor (not shown) of the window regulator is driven to move the door glass  21  upward from below the run channel structure  20 , as indicated by an arrow a. 
   In  FIG. 5B , the upper edge portion  21   a  of the door glass  21  abuts on the distal end portion  61  of the inner lip  36 . Upon the abutment of the door glass  21  on the inner lip  36 , the inner lip  36  is pressed by the door glass  21  towards the inner wall  32  of the run channel structure  20 . 
   The distal end portion  61  of the inner lip  36  is turned on the proximal portion  36   a  towards the inner wall  32  of the run channel structure  20 , as indicated by an arrow b, to thereby bring the projection  61   a , provided at the distal end portion  61  of the inner lip  36 , into abutment on the upper lip  58 . 
   In  FIG. 5C , by thus abutting on the upper lip  58 , the projection  61   a  of the inner lip  36  presses the upper lip  58 . 
   Because the projection  61   a  of the inner lip  36  presses the upper lip  58 , the upper lip  58  exerts a reaction force on the projection  61   a  of the inner lip  36 . This causes the inner lip  36  to exert a relatively large reaction force on the door glass  21 , such that a speed (ascent speed) at which the door glass  21  moves upward in the direction of the arrow a is satisfactorily reduced by the reaction force of the inner lip  36 . In this state, the upper edge portion  21   a  of the door glass  21  abuts on the outer lip  38 . 
   Next, the reason why the hollow cross-sectional portion  62  is defined by the upper lip  58 , the upper portion  32   d  of the inner wall  32  and the peak portion  34  will be explained. 
   Because the upper lip  58  is one side of the generally triangle of the hollow cross-sectional portion  62 , the upper and lower end portions  58   a ,  58   b  (opposite end portions) of the upper lip  58  are supported. With this arrangement, a relatively large reaction force of the upper lip  58  is securely produced when the projection  61   a  of the inner lip  36  presses the upper lip  58 . 
   In addition, because the upper lip  58  is the one side of the generally triangle of the hollow cross-sectional portion  62 , an air within the inner space  64  of the hollow cross-sectional portion  62  does not flow out through the air releasing hole  63  immediately after the projection  61   a  of the inner lip  36  presses the upper lip  58 . This arrangement increases an internal pressure within the inner space  64  of the hollow cross-sectional portion  62 . The increase in internal pressure enables the upper lip  58  to act as a cushion more effectively to thereby ensure production of a relatively large reaction force of the upper lip  58 . 
   Because the reaction force of the upper lip  58  is applied to the projection  61   a  of the inner lip  36 , production of a sufficient reaction force to be exerted by the inner lip  36  on the door glass  21  is ensured. The reaction force of the inner lip  36  more satisfactorily reduces the ascent speed of the door glass  21 . 
     FIG. 6A  through  FIG. 6C  show an instance in which the upper edge portion of the door glass is inserted into the run channel structure. 
   In  FIG. 6A , after the projection  61   a  of the inner lip  36  presses the upper lip  58 , the upper edge portion  21   a  of the door glass  21  abuts on the upper lip  58 . 
   The door glass  21  abuts on the upper lip  58  after abutting on the inner lip  36 . Namely, the ascent speed at which the door glass  21  moves upward, as indicated by the arrow a, is reduced through the two steps. Accordingly, the ascent speed of the door glass  21  is more effectively reduced. 
   In  FIG. 6B , after the door glass  21  abuts on the inner lip  36 , the inner lip  36  abuts on the upper lip  58  whereupon the air within the inner space  64  of the hollow cross-sectional portion  62  flows into the air through the air releasing hole  63  and an opening portion  66  formed in the sash peak portion  56 , as indicated by an arrow c. 
   Because the upper lip  58  has undergone a pressing force of the door glass  21  since the abutment of the door glass  21  on the upper lip  58 , the upper lip  58  is sufficiently curved into a concave configuration. This causes the upper lip  58  to produce a large reaction force for satisfactorily reducing the speed (ascent speed) at which the door glass  21  moves upward in the direction of the arrow a. 
   Because the hollow cross-sectional portion  62  has the air releasing hole  63  communicating with the air, it becomes possible to easily adjust an increase in internal pressure of the hollow cross-sectional portion  62  which occurs when the projection  61   a  of the inner lip  36  presses the upper lip  58 . The adjustment of the internal pressure of the hollow cross-sectional portion  62  enables adjustment of the reaction force of the inner lip  36  and adjustment of the reaction force of the upper lip  58 . Therefore, the ascent speed of the door glass  21  can be satisfactorily adjusted. 
   For the purpose of adjustment of increase in the internal pressure of the hollow cross-sectional portion  62 , the number of the air releasing holes  63  or the diameter of the air releasing hole  63  may be adjusted. 
     FIG. 6B  shows the sash peak portion  56  having the opening portion  66  formed therein for the purpose of facilitating an understanding of the flow of the air, however, there is no need to form the opening portion  66  in the sash peak portion  56  so long as the air having flowed through the air releasing hole  63  of the hollow cross-sectional portion  62  towards the sash peak portion  56  is released into the air. 
   In  FIG. 6C , when the door glass  21  moves further upward, the upper lip  58  is lifted up by the door glass  21 . The peak portion  34  is lifted up, together with the upper lip  58 , into abutment on the sash peak portion  56 . This abutment of the peak portion  34  on the sash peak portion  56  prevents further upward movement of the door glass  21 . At this time, a load exceeding a threshold level is applied to the window regulator (not shown) and an operation of the electric motor (not shown) of the window regulator is stopped with the result that the upward movement of the door glass  21  is stopped. 
   As explained above, when the door glass  21  moves to the closed position, the door glass  21  firstly abuts on the inner lip  36  and then the projection  61   a  of the inner lip  36  presses the upper lip  58 . As a result, the reaction force of the inner lip  36  becomes relatively large. By virtue of such a relatively large reaction force of the inner lip  36 , the ascent speed of the door glass  21  is satisfactorily reduced. 
   The upper and lower end portions  58   a ,  58   b  of the upper lip  58  are supported because the upper lip  58  is the one side of the hollow cross-sectional portion  62  of the generally triangle. This arrangement ensures the production of the relatively large reaction force of the upper lip  58 . 
   When the projection  61   a  of the inner lip  36  presses the upper lip  58 , the internal pressure of the hollow cross-sectional portion  62  increases. This causes the upper lip  58  to act as a cushion more effectively for producing a relatively large reaction force. Accordingly, the ascent speed of the door glass  21  is satisfactorily reduced by the reaction force of the inner lip  36 . 
   Next, the upper edge portion  21   a  of the door glass  21  abuts on the upper lip  58 . After the door glass  21  abuts on the inner lip  36 , the inner lip  36  abuts on the upper lip  58 . Therefore, the ascent speed at which the door glass  21  moves upward as indicated by the arrow a is reduced through the two steps. As a result, the ascent speed of the door glass  21  is satisfactorily reduced. 
   At this time, the air within the inner space  64  of the hollow cross-sectional portion  62  flows into the air. Then, the upper lip  58  is sufficiently curved into a concave configuration for producing a large reaction force. Thus, the ascent speed of the door glass  21  is reduced more satisfactorily and the upper edge portion  21   a  of the door glass  21  abuts on the peak portion  34  with the peak portion  34  abutting on the sash peak portion  56 . Therefore, “glass strike sound”, namely, a sound produced when the upper edge portion  21   a  of the door glass  21  abuts on the peak portion  34  of the run channel structure  20  can be reduced. 
     FIG. 7A  through  FIG. 7C  show an instance in which an upper edge portion  81   a  of a door glass  81  is inserted into a run channel structure  80  such as provided in a comparative example. The run channel structure  80  in this comparative example is the run channel structure  20  of the present invention, but with selected structural features removed including the upper lip  58 , the air releasing hole  63 , and the projection  61   a  structures (see  FIGS. 3 and 4 ) to help facilitate discussion of some advantages of the present invention over the comparative example. 
   As shown in  FIG. 7A , an electric motor (not shown) of a window regulator is driven to raise the door glass  81  from below the run channel structure  80  of the comparative example, as indicated by an arrow d. 
   As shown in  FIG. 7B , the upper edge portion  81   a  of the door glass  81  abuts on a distal end portion  83  of an inner lip  82 . Upon the abutment of the door glass  81  on the inner lip  82 , the inner lip  82  is pressed by the door glass  81  towards an inner wall  84  of the run channel structure  80  of the comparative example. In this state, a reaction force of the inner lip  82  is applied to the door glass  81 . 
   This reaction force of the inner lip  82  is less large relative to the preferred embodiment of the invention because the distal end portion  83  of the inner lip  82  is a free end. Accordingly, the reaction force of the inner lip  82  is insufficient to satisfactorily reduce an ascent speed of the door glass  81 . 
   As shown in  FIG. 7C , the upper edge portion  81   a  of the door glass  81  comes into abutment on a peak portion  86  of the run channel structure  80  of the comparative example at a relatively high speed as compared against the preferred embodiment of the invention. The peak portion  86  is pushed upward by a pressing force of the door glass  81  into abutment on a sash peak portion  87 . This abutment of the peak portion  86  on the sash peak portion  87  prevents the door glass from moving further upward. At this time, a load exceeding a threshold level is applied to the window regulator (not shown) to thereby stop an operation of the electric motor (not shown) of the window regulator with the result that the door glass  81  stops moving upward. 
   As discussed above, the upper edge portion  81   a  of the door glass  81  abuts on the peak portion  86  of the run channel structure  80  at the relatively high speed as compared against the preferred embodiment of the invention. Thus, it is difficult using structure of the comparative example such as shown in  FIG. 7A  through  FIG. 7C  to reduce “glass strike sound”, that is, a sound produced when the upper edge portion  81   a  of the door glass  81  abuts on the peak portion  86  of the run channel structure  80 . 
   Although the present invention has been described as being applied to the run channel structure  20  of the right front sash door  13  in the illustrated embodiment, the run channel structure  20  is also applicable to the left front sash door  12  or the left and right rear sash doors  14 ,  15  in the same manner. 
   Although in the illustrated embodiment, the projection  61   a  is provided at the distal end portion  61  of the inner lip  36  and the projection  61   a  presses the upper lip  58 , the distal end portion  61  of the inner lip  36  may not have the projection  61   a  and may press the upper lip  58 . 
   Obviously, various minor changes and modifications of the present invention are possible in the light of the above teaching. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.