Abstract:
A shielded connector assembly has first and second housings ( 11, 31 ). The first housing ( 11 ) has a fitting space ( 17 ) formed with coupling ribs ( 16 ). A shielding shell ( 26 ) is in the fitting space ( 17 ) and has slits ( 27 ) that receive the coupling ribs ( 16 ). A preventing groove ( 29 ) is formed in a peripheral surface of a fitting space ( 17 ) and receives a projection ( 37 ) of the second housing ( 31 ) when the housings ( 11, 31 ) are connected properly. The preventing groove ( 29 ) is aligned with the slit ( 27 ) so that the slit ( 27 ) also receives the projection ( 37 ). Thus, it is unnecessary to form a separate notch to receive the projection ( 37 ).

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to a shielded connector, to a mating shielded connector connectable therewith and to a shielded connector assembly. 
   2. Description of the Related Art 
   A known shielded connector has terminal fittings accommodated in a housing made of a synthetic resin. The connector further includes a tubular metallic shielding shell assembled into the housing to absorb noise from the terminal fittings and to prevent leakage of noise to the outside of the housing. 
   The housing of one known shielding connector has a terminal accommodating portion surrounded by a tubular fitting. The outer peripheral surface of the terminal accommodating portion and the inner peripheral surface of the tubular fitting are coupled by a coupling rib, and a fitting space is defined between the terminal accommodating portion and the tubular fitting portion for accommodating a shielding shell. The shielding shell is formed with a slit that receives the coupling rib as the shielding shell is inserted into the fitting space. 
   The above-described shielded connector is used with a mating shielded connector as a mating partner of this shielded connector that has terminal fittings accommodated in a housing. Outer surfaces of the housing and a receptacle formed on the housing are surrounded by a shielding shell. The receptacle is fit into the fitting space when the housing and the mating housing are connected to bring both shielding shells into contact so that the peripheral surfaces of the shielding shells overlap. 
   Japanese Unexamined Patent Publication No. 2002-319458 discloses a shielded connector with many of the features described above. 
   Most connector assemblies have a projection formed on the outer peripheral surface of one connector and a groove formed in a fitting space of the other connector. The projection and the groove prevent the connectors from being connected erroneously in an inverted orientation. 
   The above-described erroneous connection preventing means could be applied to shielded connectors. However, the shielding shell would have to be formed with a notch for avoiding interference with the projection in addition to the slit for avoiding the interference with the coupling rib. The slit and the notch can be paths for leaking noise to the outside of the shielding shells. Thus, a shielding function of the shielding shells may be reduced. 
   The present invention was developed in view of the above problem, and an object thereof is to suppress a reduction in a shielding function. 
   SUMMARY OF THE INVENTION 
   The invention relates to a shielded connector that is connectable with a mating shielded connector. The shielded connector has a housing with at least one terminal accommodating portion that is at least partly surrounded by a tubular fitting. The outer peripheral surface of the terminal accommodating portion and the inner peripheral surface of the tubular fitting are coupled by at least one coupling rib so that a fitting space is defined between the terminal accommodating portion and the tubular fitting. The connector further includes a substantially tubular shielding shell formed with at least one slit extending from an end edge of the shielding shell. The shielding shell is mounted in the fitting space so that the slit engages the coupling ribs. The mating shielded connector has a mating housing that is configured to fit into the fitting space. The peripheral surface of the fitting space where the shielding shell is provided is formed with at least one erroneous connection preventing portion for preventing an improper assembling of the housing with the mating housing. The erroneous connection preventing portion is at a location in the fitting space substantially corresponding to the slit. 
   The erroneous connection preventing portion may comprise a projection and/or a recess. 
   The shielded connector preferably is connectable to the mating shielded connector by at least partly overlapping the peripheral surfaces of the shielding shell with a mating shielding shell of the mating shielded connector. 
   A movable member such as a lever or a slider preferably is provided and displays a cam action to assist or perform the connection of the shielded connector with the mating shielded connector. 
   The invention also relates to a shielded connector assembly comprising the above-described shielded connector and a mating shielded connector that are connectable with each other. 
   The mating shielded connector preferably has a mating housing, and a mating shielding shell surrounds the second housing. The shielded connectors are connected by fitting the mating housing into the fitting space and overlapping the peripheral surfaces of the shielding shells. The fitting space and the mating housing have erroneous connection preventing portions in the form of a projection and a recess for preventing an improper assembly of the housings. The erroneous connection preventing portion of the fitting space is at a position corresponding to the slit. 
   The shielding shell must have a notch corresponding to the erroneous connection preventing portion of the fitting space to engage the erroneous connection preventing portion of the mating housing. According to the invention, the erroneous connection preventing portion of the fitting space is disposed to correspond to the slit. The slit for avoiding interference with the coupling rib also is the notch for engaging the erroneous connection preventing portions. Thus, it is not necessary to form the notch and a separate slit and noise leakage paths are reduced. 
   These and other objects, features and advantages of the present invention will become more apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings. It should be understood that even though embodiments are separately described, single features thereof may be combined to additional embodiments. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a first shielded connector. 
       FIG. 2  is a front view of the first shielded connector. 
       FIG. 3  is an exploded perspective view of the first shielded connector. 
       FIG. 4  is a perspective view of a second shielded connector. 
       FIG. 5  is a front view of the second shielded connector. 
       FIG. 6  is an exploded perspective view of the second shielded connector. 
       FIG. 7  is a vertical section showing a state where the two shielded connectors are connected. 
       FIG. 8  is a horizontal section showing a state where the two shielded connectors are separated. 
       FIG. 9  is a horizontal section showing the state where the two shielded connectors are connected. 
       FIG. 10  is a front view of a first shielding shell. 
       FIG. 11  is a section along X—X of  FIG. 10 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A shielded connector assembly according to the invention has first and second shielded connectors  10  and  30 , as shown in  FIGS. 1 to 11 . The first and second shielded connectors  10  and  30  are configured to be connected with and separated from each other. Mating sides of the first and second shielded connectors  10  and  30  are referred to as the front herein. 
   The first shielded connector  10  includes a first housing  11  that is molded integrally or unitarily of e.g. a synthetic resin. The first housing  11  has block-shaped terminal accommodating portions  12  and a rectangular tubular fitting  13  that substantially surrounds the terminal accommodating portions  12 . The terminal accommodating portions  12  are arranged substantially side-by-side and are coupled to one another at their rear ends. First terminal fittings  14  are inserted into the respective terminal accommodating portions  12  from behind. An unshielded wire  15  is connected with the rear end of each first terminal fitting  14 , and is drawn out of the first housing  11  through the rear end of the terminal accommodating portion  12 . 
   The tubular fitting  13  extends in forward and backward directions FBD from the front ends of the terminal accommodating portions  12  to a position behind the rear ends of the terminal accommodating portions  12 . Left and right coupling ribs  16  are formed at the rear ends of upper and lower outer peripheral surfaces of the terminal accommodating portions  12  to couple the terminal accommodating portions  12  and the tubular fitting  13  and to hold a specified positional relationship. A substantially rectangular fitting space  17  is defined between the outer peripheral surfaces of the terminal accommodating portions  12  and the tubular fitting  13 . The fitting space  17  has an open front end and is substantially continuous over substantially the entire periphery. An accommodation space  18  is defined in area in the tubular fitting  13  behind the terminal accommodating portions  12  for accommodating a connection shell  19 . The connection shell  19  is to be secured to an end of a shielding layer  20  (e.g. a braided wire or a metal shielding layer) for surrounding and shielding the wires  15  drawn out backward from the first housing  11 . 
   A lever  22  is mounted on the first housing  11  and is rotatable about supporting shafts  21  formed on the left and right outer surfaces of the tubular fitting  13 . Plate-like left and right arms  23  of the lever  22  are arranged along the outer side surfaces of the tubular fitting  13 , and cam grooves  24  are formed in the surfaces of the arms  23  facing the tubular fitting  13 . On the other hand, the tubular fitting  13  is formed with escaping grooves  25  that are substantially straight cuts formed to extend back from the front ends of the left and right walls of the tubular fitting  13 . 
   The first connector  10  further has a rectangular tubular first shell  26  preferably formed by deep drawing a metal sheet (e.g. an aluminum alloy) to gradually deform the metal sheet by repeating a plurality of pressing operations. Thus, the tubular first shell  26  has no seam in the peripheral direction. Left and right slits  27  extend back from the front ends of the upper and lower plates of the first shielding shell  26  at positions corresponding to the coupling ribs  16 . The front end of the first shielding shell  26  is located at a position slightly behind the escaping grooves  25  of the tubular fitting  13 . 
   The first shielding shell  26  is mounted into the fitting space  17  of the first housing  11  substantially along the inner peripheral surface of the tubular fitting  13  from behind. In the assembling process, the slits  27  engage the coupling ribs  16 . When the first shielding shell  26  reaches a proper assembled position, the outer peripheral surface of the first shielding shell  26  is held in close contact with a great part of the inner peripheral surface of the tubular fitting  13 , a front part of the first shielding shell  26  is in a rear part of the fitting space  17 , and a rear part of the first shielding shell  26  is in the accommodation space  18 . The first shielding shell  26  shields rear parts of the first terminal fittings  14  inserted in the terminal accommodating portions  12  and areas of the wires  15  accommodated in the tubular fitting  13  by surrounding them substantially over the entire periphery. 
   The connection shell  19  is mounted into the accommodation space  18  from behind so that the outer peripheral surface of the connection shell  19  at least partly overlaps the inner peripheral surface of the rear end of the first shielding shell  26 . Resilient contact pieces  26   a  are formed close to the rear end of the first shielding shell  26  and contact the outer surfaces of the connection shell  19  to electrically connect the first shielding shell  26  and the connection shell  19 . The connection shell  19  is retained by a holder  28  mounted to the rear end of the first housing  11 . 
   The second shielded connector  30  includes a second housing  31  made e.g. of a synthetic resin. A receptacle  32  is formed at the front of the second housing  31  and is configured to fit in the fitting space  17 . The receptacle  32  is partitioned into three fitting recesses  33  having opening front ends, and long narrow second (male) terminal fittings  34  are accommodated in the respective fitting recesses  33 . A rectangular tubular second shielding shell  35  is mounted in close contact with the outer peripheral surface of the second housing  31 . The second shielding shell  35  is a united assembly of upper and lower divided elements  35   a ,  35   b , and surrounds the entire area of the second housing  31  from the front end to the rear end over substantially the entire periphery. Cylindrical cam followers  36  project out from the left and right outer side surfaces of the second housing  31 , and parts of the second shielding shell  35  corresponding to the cam followers  36  are notched. 
   Means also are provided for preventing connection of shielding connectors  10 ,  30  in improper postures or in an improper combination. 
   The first shielding connector  10  is formed with a preventing groove  29  of substantially rectangular cross section in the inner peripheral surface of the tubular fitting  13 , which is the peripheral surface on which the first shielding shell  26  is arranged. The preventing groove  29  is a substantially straight cut extending back from the front end of the tubular fitting  13  and is in an area from the front end of the tubular fitting  13  to the coupling ribs  16 . The preventing groove  29  is at a position substantially corresponding to the coupling ribs  16  with respect to transverse direction TD, and the width of the preventing groove  29  is substantially equal to the widths of the coupling ribs  16  and the slits  27 . Thus, the preventing groove  29  is located to correspond to the slit  27  and the coupling rib  16  is behind and on an extension of the preventing groove  29 . 
   On the other hand, the second shielded connector  30  has a least one projection  37  at the front end of the outer lower surface of the receptacle  32 . A front end of the second shielding shell  35  has a notch  38  only in an area where the projection  37  is formed. The projection  3  projects out and down through the notch  38 . If the first and second shielded connectors  10 ,  30  are connected in a correct combination and in substantially proper postures (e.g. without being vertical inverted), the connecting operation of the two shielded connectors  10 ,  30  progresses as the projection  37  is fit into the preventing groove  29 . Conversely, if an attempt is made to connect the first and second shielded connectors  10 ,  30  in a wrong combination or in improper postures (e.g. vertically inverted), the projection  37  contacts the front edge of the tubular fitting  13 , to hinder the connection of the two shielded connectors  10 ,  30 . 
   Upon connecting the two shielded connectors in a correct combination and in substantially proper postures, the receptacle  32  is fit lightly into the fitting space  17  and the terminal accommodating portions  12  are fit lightly into the fitting recesses  33  while the projection  37  engages the preventing groove  29  and the slit  27 . The cam followers  36  then enter the cam grooves  24 . The movable member  22  then is operated, and the shielded connectors  10 ,  30  are pulled together by a cam action resulting from the engagement of the cam followers  36  and the cam grooves  24  to assist the connecting operation. During the connecting operation, the front part of the second shielding shell  35  enters the front part of the inner space of the first shielding shell  26  so that the outer peripheral surface of the second shielding shell  35  and the inner peripheral surface of the first shielding shell  26  overlap. 
   With the two shielded connectors  10 ,  30  connected, the second shielding shell  35  is partly inside the first shielding shell  26 , and the front ends of the two shielding shells  26 ,  35  overlap in longitudinal and transverse directions. Further, the resilient contact pieces  26   b  at the front end of the first shielding shell  26  resiliently contact the outer peripheral surface of the second shielding shell  35  so that the two shielding shells  26 ,  35  are connected electrically. In addition, front ends of the second terminal fittings  34  enter the terminal accommodating portions  12  to be connected electrically with the first terminal fittings  14 . The rear parts of the first terminal fittings  14  are surrounded by the first shielding shell  26  as described above. By connecting the two shielded connectors  10 ,  30 , front parts of the first terminal fittings  14  are surrounded by the second shielding shell  35 . In this way, conduction paths formed by the terminal fittings  14 ,  34  in the first and second housings  11 ,  31  are substantially shielded by the two shielding shells  26 ,  35 . 
   As described above, the preventing groove  29  is formed in the peripheral surface of the fitting space  17  and specifically in the inner peripheral surface of the tubular fitting  13 . Thus, the first shielding shell  26  needs to be formed with the notch corresponding to the preventing groove  29  to enable the engagement of the preventing groove  26  with the projection  37  as the error connection preventing portion of the second housing  31 . However, the preventing groove  29  corresponds to one of the slits  27 . Thus, the slit  27  is the means for avoiding the interference with the coupling rib  16  and also is the notch for enabling the engagement of the projection  37  and the preventing groove  29 . Accordingly, the first shielding shell  26  needs not be formed with a notch in addition to the slits  27 , thereby avoiding an increase in noise leakage paths in the first shielding shell  26  to suppress a reduction in the shielding function by the first shielding shell  26 . 
   The invention is not limited to the above described and illustrated embodiment. For example, the following embodiments are also embraced by the technical scope of the present invention as defined by the claims. Beside the following embodiments, various changes can be made without departing from the scope and spirit of the present invention as defined by the claims. 
   Although the first and second shielded connectors are connected using the lever in the foregoing embodiment, the invention is also applicable to connect the first and second shielded connectors without using the lever or having other movable members such as sliders for assisting or performing the connection of the first and second shielded connectors. 
   Although one projection and one preventing groove are provided as the erroneous connection preventing portions in the foregoing embodiment, a plurality of projections or ribs and/or a plurality of preventing grooves or recesses may be provided according to the present invention. 
   Although the first shielding shell and the erroneous connection preventing portion extend substantially along the inner peripheral surface of the tubular fitting in the foregoing embodiment, they may be provided to extend along the outer peripheral surfaces of the terminal accommodating portions. 
   Although the erroneous connection preventing portion of the fitting space is the preventing groove and that of the second housing is the projection in the foregoing embodiment, the erroneous connection preventing portion of the fitting space may be the projection and that of the second housing may be the preventing groove according to the invention.