Patent Publication Number: US-8979584-B2

Title: Board-mounted connector

Description:
TECHNICAL FIELD 
     The present invention relates to a board-mounted connector which includes a shield shell for noise resistance or the like, and can be attached onto a circuit board. 
     BACKGROUND ART 
       FIGS. 8 to 10  are views illustrating a board-mounted connector disclosed in the following Patent Document 1. 
     This board-mounted connector  101  includes an external shield shell  111  and a housing assembly  121 . 
     A lower surface  112  which is one surface of the external shield shell  111  is attached onto a circuit board (not shown) such that an electromagnetic shielding space  114  is formed between the external shield shell  111  and the circuit board as shown in  FIG. 9 . The external shield shell  111  has a front side  113  which is one side perpendicular to a surface of the circuit board and is open for fitting a counterpart connector. 
     The housing assembly  121  is fit into the external shield shell  111 . The counterpart connector is inserted from the open portion on one side of the external shield shell  111  and is fit into the housing assembly  121 , thereby being connected to the housing assembly  121 . 
     As shown in  FIG. 9 , the housing assembly  121  includes a connection terminal member  122  having one end that is a lead terminal  122   a  to be connected to a contact node on the circuit board and the other end that is a connector terminal  122   b  to be fit into a connection terminal of the counterpart connector, thereby being connected thereto, an internal housing  123  that is made of an insulating resin and accommodates the connection terminal member, an internal shield shell  125  that covers the outer circumference of the internal housing  123  and can be conductively connected to a corresponding shield member of the counterpart connector, and an external housing  126  that is made of an insulating resin and accommodates and holds the internal shield shell  125 . 
     An arrow X 1  shown in  FIG. 8  represents an insertion/extraction direction (fitting direction) of the counterpart connector with respect to the board-mounted connector  101 , which is a direction parallel to the surface of the circuit board. 
     In a case of the board-mounted connector  101 , from the beginning, the external shield shell  111  is formed in a shape shown in  FIG. 10 . In other words, a wall member  116  to be a rear wall to face the open front side  113  is formed in a shape extending in the extension direction of a top wall  117  and open on the rear side as shown in  FIG. 10 . After the housing assembly  121  is fit from the rear side of the external shield shell  111  into the external shield shell  111 , the wall member  116  is bent in a direction shown by an arrow X 2  in  FIG. 10 , thereby holding the housing assembly  121  inside the external shield shell  111 . 
     Also, when the housing assembly  121  is fit into the external shield shell  111 , as shown in  FIGS. 8 and 10 , protrusions  126   a  provided to protrude from the outer surfaces of the external housing  126  are engaged with notches  118  formed at corresponding positions of the external shield shell  111 , whereby guiding in the insertion direction is made. 
     PRIOR ART DOCUMENT 
     Patent Documents 
     Patent Document 1: JP-A-2009-64716 
     &lt;Defects of Board Mounted Connector Disclosed in Patent Document 1&gt; 
     However, in a process of assembling the board-mounted connector  101  of Patent Document 1, after the housing assembly  121  is fit into the external shield shell  111 , it takes a lot of time and trouble to bend the wall member  116  to be the rear wall of the external shield shell  111 . Therefore, there is a problem in which workability in the assembling is poor. 
     Also, when the wall member  116  is bent, since a large load is applied to the external shield shell  111 , the inner wall surface of the external shield shell  111  or the like may be deformed, and when the counterpart connector is fit into the board-mounted connector, thereby being connected to the board-mounted connector, this deformation of the external shield shell  111  may cause a trouble such as a bad connection. 
     &lt;Board-Mounted Connector as Prior Invention of this Application&#39;s Invention&gt; 
     For this reason, in order to overcome the defects (poor workability in assembling, and a reduction in assembly accuracy attributable to deformation of the external shield shell) of the board-mounted connector disclosed in Patent Document  1 , the applicant of this application considered a board-mounted connector having an assembly fitting opening provided on the attachment surface side of an external shield shell onto a circuit board so as to allow a housing assembly to be fit from the assembly fitting opening. 
       FIG. 11  is a perspective view illustrating a board-mounted connector of the prior invention considered in that way, and  FIG. 12  is an exploded perspective view illustrating the board-mounted connector shown in  FIG. 11 . 
     In a case of the board-mounted connector  1  of the prior invention shown in  FIGS. 11 and 12 , an external shield shell  11  capable of accommodating an housing assembly  21  and having one surface attachable to a circuit board has an assembly fitting opening  34  which is provided on the attachment surface side onto the circuit board such that the housing assembly  21  can be fit. 
     As shown in  FIG. 12 , the housing assembly  21  includes an internal housing  23  that is made of an insulating resin and accommodates a plurality of connection terminal members  22  at predetermined arrangement pitches, an internal shield shell  25  that is formed with a metal plate, covers the outer circumference of the internal housing  23 , and can be conductively connected to a corresponding shield member of a counterpart connector, and an external housing  26  that is made of an insulating resin and accommodates and holds the internal shield shell  25 . 
     Each connection terminal member  22  accommodated in the internal housing  23  has one end that is a lead terminal  22   a  to be connected to a contact node on the circuit board and the other end that is a connector terminal  22   b  to be fit into a connection terminal of the counterpart connector, thereby being connected thereto. By insert molding, the connection terminal members  22  are integrally supported by the internal housing  23 . 
     The internal housing  23  is fit into the internal shield shell  25  as shown by an arrow X 3 , and then the internal shield shell  25  is fit into the external housing  26  as shown by an arrow X 4 , whereby the housing assembly  21  becomes an integral assembly. 
     The assembled housing assembly  21  is fit from the assembly fitting opening  34  of the external shield shell  11  into the external shield shell  11  as shown by an arrow X 5  in  FIG. 12 , thereby being assembled with the external shield shell  11 . 
     Also, in the case of the board-mounted connector  1  of the prior invention, at both side walls of the external shield shell  11 , notch portions  39  are provided for positioning the housing assembly  21 . When the housing assembly  21  is assembled with the external shield shell  11 , protrusions  26  formed to protrude from both sides of the external housing  26  are fit into the notch portions  39 , whereby the housing assembly  21  is positioned with respect to the external shield shell  11 . 
     &lt;Problems of Prior Invention&gt; 
     However, the internal housing  23  is a small component separate from the external housing  26  and thus is hard to deal with. Therefore, the above-mentioned housing assembly  21  has a problem in which ease of assembly is bad. 
     Also, the shielding performance of the external shield shell  11  may be reduced due to the notch portions  39 . 
     SUMMARY OF INVENTION 
     Problems to be Solved by Invention 
     For this reason, objects of the present invention are to provide a board-mounted connector which has an assembly fitting opening that is provided on the attachment surface side of an external shield shell onto a circuit board such that a housing assembly can be fit from the assembly fitting opening into the external shield shell, and is capable of improving the ease of assembling the housing assembly, and a board-mounted connector which has an assembly fitting opening that is provided on the attachment surface side of an external shield shell onto a circuit board such that a housing assembly can be fit from the assembly fitting opening into the external shield shell, and is capable of improving the shielding performance of the external shield shell. 
     Means for Solving Problems 
     The above-mentioned objects of the present invention can be achieved by the following configurations. 
     (1) A board-mounted connector comprising an external shield shell having one surface that is attached onto a circuit board so as to form an electromagnetic shielding space between the external shield shell and the circuit board and one side that is perpendicular to a surface of the circuit board and is open for fitting a counterpart connector, and a housing assembly that is fit into the external shield shell and into and to which the counterpart connector is fit and connected from the one side of the external shield shell, 
     wherein the housing assembly includes connection terminal members each of which has one end that is a lead terminal which is connected to a contact node on the circuit board, and the other end that is a connector terminal which is fit into and connected to a connection terminal of the counterpart connector, an internal housing that is made of an insulating resin and accommodates the connection terminal members, an internal shield shell that covers an outer circumference of the internal housing and is conductively connected to a corresponding shield member of the counterpart connector, and an external housing that is made of an insulating resin and accommodates and holds the internal shield shell, and 
     wherein the external shield shell is provided with an assembly fitting opening which is formed on an attachment surface side with respect to the circuit board such that the housing assembly can be fit thereinto, and 
     wherein the internal housing and the external housing which constitute the housing assembly are integrally formed. 
     (2) The board-mounted connector according to (1), 
     wherein on inner surfaces of both side walls of the external shield shell, positioning spring members are provided to extend along a fitting direction of the housing assembly, and 
     wherein at both side surfaces of the external housing, guide grooves are provided to be engaged with the positioning spring members during fitting into the external shield shell, thereby performing positioning. 
     According to the above-mentioned configuration (1), the fitting of the housing assembly into the external shield shell is performed from the assembly fitting opening provided on the attachment surface side of the external shield onto the circuit board. Therefore, after the housing assembly is fit, bending a wall member of the external shield shell requiring a lot of time and trouble is unnecessary. 
     Therefore, workability in assembling is good. 
     Further, since bending a wall member having caused a large load to be applied to the external shield shell becomes unnecessary, it is possible to achieve a high-accuracy assembled state without causing deformation of the inner wall surface of the external shield shell or the like during assembling. 
     Also, according to the above-mentioned configuration (1), the internal housing and the external housing which are components of the housing assembly are integrally formed. Therefore, it is possible to reduce the number of components of the housing assembly, thereby simplifying the assembling process. Further, since the internal housing and the external housing are integrally formed, the assembly component has a size easy to deal with, and thus the ease of handling during assembling is improved. 
     Therefore, it is possible to improve the ease of assembling the housing assembly. 
     According to the above-mentioned configuration (2), when the housing assembly is fit into the external shield shell, the positioning spring members on the inner surfaces of both side walls of the external shield shell are engaged with the guide grooves of both side surfaces of the external housing, whereby the external housing and the external shield shell are positioned. Therefore, it becomes unnecessary to provide notch portions for positioning the external housing at the external shield shell. As a result, it is possible to improve the shielding performance of the external shield shell. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a first embodiment of a board-mounted connector according to the present invention. 
         FIG. 2  is an exploded perspective view of the board-mounted connector of the first embodiment. 
         FIG. 3  is a front view of an external shield shell shown in  FIG. 2 . 
         FIG. 4  is a perspective view of a second embodiment of the board-mounted connector according to the present invention. 
         FIG. 5  is an exploded perspective view of the board-mounted connector of the second embodiment. 
         FIG. 6  is an explanatory view of a process of assembling the board-mounted connector of the second embodiment. 
         FIG. 7  is a bottom view of the board-mounted connector of  FIG. 3 . 
         FIG. 8  is a perspective view of a board-mounted connector according to the related art. 
         FIG. 9  is a longitudinal sectional view of the board-mounted connector of  FIG. 8 . 
         FIG. 10  is an explanatory view of a process of assembling the board-mounted connector shown in  FIG. 9 . 
         FIG. 11  is a perspective view of a board-mounted connector of a prior invention. 
         FIG. 12  is an exploded perspective view of the board-mounted connector shown in  FIG. 11 . 
     
    
    
     EMBODIMENTS OF INVENTION 
     Hereinafter, appropriate embodiments of a board-mounted connector according to the present invention will be described in detail with reference to the drawings. 
     [First Embodiment] 
       FIGS. 1 and 2  show a first embodiment of the board-mounted connector according to the present invention,  FIG. 1  is a perspective view of the board-mounted connector of the first embodiment of the present invention,  FIG. 2  is an exploded perspective view of the board-mounted connector of the first embodiment, and  FIG. 3  is a front view of an external shield shell shown in  FIG. 2 . 
     The board-mounted connector  1 A of the first embodiment includes an external shield shell  11 A and a housing assembly  21 A. 
     The external shield shell  11 A is formed by pressing a metal plate. The basic configuration of the external shield shell  11 A may be the same as that of the external shield shell  11  of the prior invention shown in  FIG. 12 . 
     A lower surface  12  which is one surface of the external shield shell  11 A becomes an attachment surface to be attached onto a circuit board (not shown). The external shield shell  11 A attached on the circuit board forms an electromagnetic shielding space  14  between the external shield shell and the circuit board. Also, the external shield shell  11 A has a front side  13  which is one side surface perpendicular to the surface of the circuit board and is open for fitting a counterpart connector. An arrow X 1  shown in  FIG. 1  represents the insertion direction of the counterpart connector. 
     On the lower surface  12  side of the external shield shell  11 A, lag portions  31  and locked pieces  32  for preventing the external shield shell from falling out are provided to protrude toward the circuit board such that the lag portions and the locked pieces can be fit into fitting holes formed at the board. 
     In a case of the present embodiment, the external shield shell  11 A has an assembly fitting opening  34  which is formed at the attachment surface onto the circuit board (that is, the lower surface  12 ) such that the housing assembly  21 A can be fit thereinto. 
     Also, the assembly fitting opening  34  is set to be far from the front side  13  open for fitting the counterpart connector by a distance L 1  as shown in  FIG. 1 . A portion of the lower surface  12  of the external shield shell  11 A adjacent to the front side  13  and corresponding to the distance L 1  is composed of connection walls  37  and  38  which connect both side walls  35  and  36  of the external shield shell  11 A. The paired connection walls  37  and  38  extend toward the center of the shell along the surface of the circuit board from the lower ends of the both side walls  35  and  36 , and are connected in a state where their end portions are face to face with each other. In the case of the present embodiment, the end portions of the connection walls  37  and  38  facing each other are connected by dovetail groove joining T as shown in  FIG. 1 . 
     The paired connection walls  37  and  38  lead the bottom surface of the counterpart connector (not shown) into the external shield shell  11 A, and functions as a housing which supports the bottom surface of the counterpart connector inserted in the external shield shell  11 A and holds the counterpart connector. 
     On the inner surfaces of the both side walls of the external shield shell  11 A as shown in  FIG. 1 , spring pieces  41  for pressing the side surfaces of the counterpart connector (not shown) inserted in the external shield shell  11 A are formed by cutting and raising. Each of the spring pieces  41  is set to have a protruding length from a corresponding side wall such that a pressing force against the corresponding side wall of the counterpart connector becomes desired strength. 
     Also, as shown in  FIG. 3 , on the inner surfaces of the both side walls  35  and  36  of the external shield shell  11 A, positioning spring members  71   a  and  71   b  are provided to extend along the fitting direction of the housing assembly  21 A. The positioning spring members  71   a  and  71   b  position the housing assembly  21 A in the left/right direction inside the external shield shell  11 A. 
     As shown in  FIG. 2 , the external shield shell  11 A includes notch portions  39  and locking holes  46  as positioning means during fitting of the housing assembly  21 A. 
     The notch portions  39  are portions which are engaged with engagement confirming protrusions  26   c  provided on an external housing  26  to be described below when the fitting of the housing assembly  21 A into the external shield shell  11 A is completed. The notch portions  39  are formed at positions visible from the outside of the external shield shell  11 A (specifically, the lower edge portions of the both side walls  35  and  36  of the external shield shell  11 A) such that the notch portions connect the inside and outside of the external shield shell  11 A. 
     When the fitting of the housing assembly  21 A into the external shield shell  11 A is completed, the locking holes  46  are engaged with engagement protrusions  26   b  of the external housing  26  to be described below, thereby fixing the housing assembly  21 A. 
     Next, the housing assembly  21  A will be described. 
     As shown in  FIG. 2 , the housing assembly  21 A is fit from the assembly fitting opening  34  into the external shield shell  11 A. The counterpart connector is inserted from an open portion on one side of the external shield shell  11 A and then is fit into the housing assembly  21 A, thereby being connected thereto. 
     As shown in  FIG. 2 , the housing assembly  21 A includes connection terminal members  22  each of which has one end that is a lead terminal  22   a  to be connected to a contact node on the circuit board and the other end that is a connector terminal  22   b  to be fit into a connection terminal of the counterpart connector, thereby being connected thereto, an internal housing  23  that is made of an insulating resin and accommodates the plurality of connection terminal members  22  at predetermined arrangement pitches, an internal shield shell  25  that is formed with a metal plate, covers the outer circumference of the internal housing  23 , and can be conductively connected to a corresponding shield member of the counterpart connector, and an external housing  26  that is made of an insulating resin and accommodates and holds the internal shield shell  25 . 
     The cross-sectional shape of the internal housing  23  perpendicular to the insertion direction of the connection terminal members  22  is almost a rectangular shape. 
     The internal shield shell  25  includes a rectangular-tube-like cylindrical portion  25   a  having a cross-sectional shape corresponding to the cross-sectional shape of the internal housing  23 . 
     In the case of the present embodiment, the internal housing  23  and the external housing  26  are made into a single complex housing  51  by integral forming Also, when the complex housing  51  is formed, the plurality of connection terminal members  22  is formed to be accommodated and held in the internal housing  23  by the insert molding. 
     The internal shield shell  25  is fit into the complex housing  51  such that the internal housing  23  is accommodated in the internal shield shell  25 , whereby assembling of the housing assembly  21 A of the present embodiment is completed. 
     In the case of the board-mounted connector  1 A of the present embodiment, the assembled housing assembly  21 A is inserted into the assembly fitting opening  34  along a direction shown by an arrow Z 1  from the lower side of the external shield shell  11 A as shown in  FIG. 2 , and is fit into the external shield shell  11 A. 
     At both side surfaces of an external housing  26 B which is interposed between the both side walls  35  and  36  of the external shield shell  11 A, guide grooves  81  are provided to be passages for the positioning spring members  71   a  and  71   b.    
     Also, on both outer surfaces of the external housing  26  which is interposed between the both side walls  35  and  36  of the external shield shell  11 A, the engagement protrusions  26   b  and the engagement confirming protrusions  26   c  are provided as shown in  FIG. 2 . 
     When the external housing  26  is inserted up to a predetermined position inside the external shield shell  11 A such that the fitting is completed, the engagement protrusions  26   b  are locked by the locking holes  46  of the external shield shell  11 A. The locking of the engagement protrusions  26   b  by the locking holes  46  causes the housing assembly  21 A to be fixed inside the external shield shell  11 A. 
     When the external housing  26  is inserted up to the predetermined position inside the external shield shell  11 A such that the fitting is completed, as shown in  FIG. 1  the engagement confirming protrusions  26   c  are fit into the notch portions  39  formed at the both side walls  35  and  36  of the external shield shell  11 A. The engagement confirming protrusions  26   c  correspond to the formation positions of the notch portions  39  on the external shield shell  11 A, and are provided to protrude from the both outer surfaces of the external housing  26 . 
     In the board-mounted connector  1 A of the first embodiment described above, the fitting of the housing assembly  21 A into the external shield shell  11 A is performed from the assembly fitting opening  34  formed on the lower surface ( 12 ) side which is the attachment surface of the external shield shell  11 A onto the circuit board. Therefore, after the housing assembly  21 A is fit, bending a wall member of the external shield shell requiring a lot of time and trouble is unnecessary. Therefore, workability in assembling is good. 
     Further, since bending a wall member having caused a large load to be applied to the external shield shell  11 A becomes unnecessary, it is possible to achieve a high-accuracy assembled state without causing deformation of the inner wall surface of the external shield shell  11 A or the like during assembling. 
     Also, in the case of the board-mounted connector  1 A of the present embodiment, the internal housing  23  and the external housing  26  which are components of the housing assembly  21 A are integrally formed. Therefore, it is possible to reduce the number of components of the housing assembly  21 A, thereby simplifying the assembling process. Further, since the internal housing  23  and the external housing  26  are integrally formed, the assembly component has a size easy to deal with, so the ease of handling during assembling is improved. 
     Therefore, it is possible to improve the ease of assembling the housing assembly. 
     [Second Embodiment] 
       FIGS. 4 to 7  are views illustrating a second embodiment of the board-mounted connector according to the present invention,  FIG. 4  is a perspective view of the board-mounted connector of the second embodiment of the present invention,  FIG. 5  is an exploded perspective view of the board-mounted connector of the second embodiment,  FIG. 6  is an explanatory view of a process of assembling the board-mounted connector of the second embodiment, and  FIG. 7  is a bottom view of the board-mounted connector of  FIG. 4 . 
     The board-mounted connector  1 B of the second embodiment includes an external shield shell  11 B and a housing assembly  21 B. 
     The external shield shell  11 B of the second embodiment has been obtained by improving a portion of the external shield shell  11 A of the first embodiment. 
     The improved points are a point in which the guide grooves  81  of an external housing  26 A of the first embodiment has been used to position the positioning spring members  71   a  and  71   b  in the front/rear direction, and a point in which the notch portions  39  provided at the external shield shell  11 A of the first embodiment has been abolished. 
     In the case of the external shield shell  11 B of the second embodiment, components other than the above-mentioned improved points may be common to the first embodiment, and the components common to the first embodiment are denoted by the same reference symbols as those in the first embodiment and will not be described. 
     The housing assembly  21 B of the second embodiment is obtained by fitting the internal shield shell  25  into a complex housing  51 B as shown in  FIG. 5 . 
     The complex housing  51 B is obtained by integrally forming the internal housing  23  and the external housing  26 B, and the basic configuration as the housing assembly is common to the first embodiment. 
     However, as compared to the external housing  26  of the first embodiment, the external housing  26 B of the second embodiment has the following improved point. 
     The improved point of the external housing  26 B of the second embodiment relative to the external housing  26  of the first embodiment is that guide grooves  81 B to position positioning spring members  71 A and  71 B in the front/rear direction and the vertical direction are provided at both side surfaces of the external housing  26 B as shown in  FIGS. 5 to 7 . The guide grooves  81 B have step portions  81   a  with which the front ends  71   a  of the positioning spring members  71  are engaged when being fit into the external shield shell  11 B as shown in  FIG. 6 , and performs positioning by the engagement with the positioning spring members  71 . The guide grooves  81 B are small as long as a play with the positioning spring members  71  in the front/rear direction is possible. 
     Further, in the external housing  26 B of the second embodiment, as an improved point according to the abolishment of the notch portions  39  in the external shield shell  11 B, the engagement confirming protrusions  26   c  included in the external housing  26  of the first embodiment are abolished. 
     In a case of the external housing  26 B of the second embodiment, components other than the above-mentioned improved points may be common to the first embodiment, and the components common to the first embodiment are denoted by the same reference symbols as those in the first embodiment and will not be described. 
     In the board-mounted connector  1 B of the second embodiment described above, in addition to the functions and effects of the first embodiment, the following functions and effects can be obtained. 
     In other words, in the board-mounted connector  1 B of the second embodiment, as shown in  FIGS. 6 and 7 , when the housing assembly  21 B is fit into the external shield shell  11 B, the positioning spring members  71  on the inner surfaces of the both side walls  35  and  36  of the external shield shell  11 B are engaged with the guide grooves  81 B at the both side surfaces of the external housing  26 B, whereby the external housing  26 B and the external shield shell  11 B are positioned in the front/rear direction and the vertical direction. Further, since the notch portions (the notch portions  39  of  FIG. 2 ) included in the external shield shell  11 A of the first embodiment are abolished in the second embodiment, as compared to the first embodiment, it is possible to improve the shielding performance. 
     Also, the board-mounted connector of the present invention is not limited to the above-mentioned individual embodiments, but can be appropriately modified and improved. Further, the materials, shapes, dimensions, and the like of the board-mounted connectors of the present invention are arbitrary as long as the objects of the present invention can be achieved, and are not limited. 
     Although the present invention has been described in detail with reference to the specific embodiments, it is apparent to those skilled in the art that it is possible to add various changes or modifications without departing from the sprit and scope of the present invention. 
     This application is based on Japanese Patent Application (Application No. 2010-194471) filed on Aug. 31, 2010 whose contents are incorporated herein by reference. 
     INDUSTRIAL APPLICABILITY 
     According to the board-mounted connectors based on the present invention, fitting of the housing assembly into the external shield shell is performed from the assembly fitting opening provided on the attachment surface side of the external shield shell onto the circuit board. Therefore, after the housing assembly is fit, bending a wall member of the external shield shell requiring a lot of time and trouble is unnecessary. 
     Therefore, workability in assembling is good. 
     Further, since bending a wall member having caused a large load to be applied to the external shield shell becomes unnecessary, it is possible to achieve a high-accuracy assembled state without causing deformation of the inner wall surface of the external shield shell or the like during assembling. 
     Also, according to the board-mounted connectors based on the present invention, the internal housing and the external housing which are components of the housing assembly are integrally formed. Therefore, it is possible to reduce the number of components of the housing assembly, thereby simplifying the assembling process. Further, since the internal housing and the external housing are integrally formed, the assembly component has a size easy to deal with, so the ease of handling during assembling is improved. 
     Therefore, it is possible to improve the ease of assembling the housing assembly. 
     DESCRIPTION OF REFERENCE NUMERALS 
       1 A,  1 B Board-Mounted Connector 
       11 A,  11 B External Shield Shell 
       13  Front Surface 
       21 A,  21 B Housing Assembly 
       22  Connection Terminal Member 
       23  Internal Housing 
       25  Internal Shield Shell 
       26 ,  26 B External Housing 
       26   b  Engagement Protrusion 
       34  Assembly Fitting Opening 
       35 ,  36  Side Wall 
       39  Notch Portion 
       41  Spring Piece 
       51 ,  51 B Complex Housing 
       71  Positioning Spring Member 
       81  Guide Groove