Patent Publication Number: US-7223124-B2

Title: Connector and a method of assembling it

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to a connector and a method of assembling it. 
   2. Description of the Related Art 
   A female connector has a housing formed with cavities for receiving female terminal fittings and a lock is formed at a side surface of each cavity for retaining the female terminal fitting in the cavity. The retained female terminal fitting is connected with a tab of a male terminal fitting inserted through a front opening of the cavity. 
   Mold-removal holes are left in the front surface of the housing as the locks are formed. Thus, leading ends of the tabs may erroneously enter the mold-removal holes if the male and female connectors are not positioned properly during connection. Erroneous insertion of the tabs has become more common in view of recent trends to miniaturize connectors. Accordingly, there is a demand for a connector that makes such erroneous insertion unlikely. 
   A terminal fitting to be accommodated in the cavity of the female connector generally has a tubular main portion with a front end and a tab insertion opening in the front end. A barrel is arranged behind the box portion and can be crimped into connection with an end of a wire. A resilient contact is folded back from the front end of the main portion and into the main portion. 
   A tab of a male terminal fitting enters the tubular main portion through the tab insertion opening when the female connector is connected properly with a mating male connector. Thus, the tab contacts the resilient contact to establish an electrical connection therebetween (see e.g. U.S. Pat. No. 5,336,540). 
   An electrical connection test for the female connector is carried out by inserting an electrically conductive probe through the tab insertion opening of the female terminal fitting to directly contact the resilient contact of the female terminal fitting. However, the probe could permanently set or plastically deformed the resilient contact. 
   The present invention was developed in view of the above problem and an object thereof is to avoid the erroneous insertion of a tab. 
   Another object of the invention is to avoid damaging the resilient contact during an electrical connection test. 
   SUMMARY OF THE INVENTION 
   The invention relates to a connector with a housing that has at least one cavity for receiving a terminal fitting. A lock is formed at an inner wall of the cavity and is configured to engage the terminal fitting. A mold-removal hole is formed in the front wall of the housing as the lock is being formed, and hence substantially aligns with the lock. A mating tab can be inserted into the cavity from the front for connection with the terminal fitting in the cavity. A flat plate-shaped front wall is mountable at the front of the housing and has at least one tab insertion hole that can communicate with the cavity. The mating tab is inserted through the tab insertion hole of the front wall and into the cavity of the housing as the connectors are connected. However, the tab cannot be inserted into the mold-removal hole. 
   The terminal fitting preferably has a main portion for receiving the tab and a resilient contact is in the main portion for contacting the tab. A detecting portion is at a position on the main portion different from the resilient contact and enables an electrical connection test to be performed. 
   The front wall preferably has at least one jig insertion hole for permitting insertion of an unlocking jig to disengage the lock from the terminal fitting. 
   The front wall preferably is held on the housing for movement between a partial locking position and a full locking position. The detecting portion substantially faces the jig insertion hole when the front wall is at the partial locking position. Thus, a jig for an electrical connection test can be inserted into the jig insertion hole from the front and can contact the detecting portion when the front wall is at the partial locking position. 
   The tab insertion hole communicates with the cavity and the jig insertion hole communicates when the mold-removal hole when the front wall is at the full locking position. Thus, a tab can pass through the tab insertion hole when the front wall is at the full locking position and can enter the main portion for contacting a resilient contact of a terminal fitting that has been inserted properly into the cavity. Additionally, an unlocking jig can pass through the jig insertion hole when the front wall is at the full locking position and can enter the mold-removal hole for displacing the lock in an unlocking direction. 
   The jig for the electrical connection test can be inserted through the jig insertion hole and into contact with the detecting portion when the front wall is at the partial locking position on the housing. The detecting portion is at a position different from the resilient contact. Thus, the electrical connection test can be conducted without touching the resilient contact, and the resilient contact will not be damaged by the probe during the electrical connection test. 
   The jig insertion hole of the front wall permits passage of the unlocking jig when the front wall is at the full locking position and permits passage of the jig for electrical connection test when the front wall is at the partial locking position. Thus, it is not necessary to separately form both holes in the front wall, and the front wall can be the simpler and smaller. 
   A front opening of the tubular main portion of the terminal fitting and the tab insertion hole of the front wall are displaced from each other when the front wall is at the partial locking position. Thus, the leading end of the jig for electrical connection test does not enter the main portion if the jig for electrical connection test is inserted inadvertently into the tab insertion hole. Thus, the contact of the jig and the resilient contact can be avoided. 
   The main portion preferably is formed with a detecting plate for at least partly covering the front opening of the main portion except an area where the tab passes. The detecting portion preferably is on the front surface of the detecting plate. Thus, a large area of contact is assured for the jig for electrical connection test and the detecting portion to increase the reliability of the electrical connection test. 
   The front wall may be joined to be integrally or unitarily with the housing by at least one hinge, thereby meeting a demand for fewer parts. 
   The front wall can be rotated about the hinge to a rotation ending position on the front surface of the housing. Thus, the front wall can be mounted on the front surface of the housing through one movement, thereby improving mounting operability. 
   A retainer mount hole is formed in a side surface of the housing for receiving a retainer that will retain a terminal fitting is at least partly mountable. The front wall can be rotated about 90° in an opening direction from the rotation ending position to an initial position. Thus, the tab insertion hole and the retainer mount hole are open in the substantially same direction when the front wall is at the initial position. Thus, the tab insertion hole can be formed by a mold for forming the retainer mount hole merely by setting the posture of the front wall at the initial position while molding the housing. Therefore, the mold can be simplified. 
   A frame preferably is mounted on the front surface of the housing for covering the side edges of the front wall. Thus, the side edges of the front wall are protected by the mounting frame, and the front wall cannot be detached inadvertently from the front surface of the housing by external matter. 
   At least one part of a surface of the front wall around the tab insertion hole can function as a front stop wall for the terminal fitting when the terminal fitting is being inserted into the cavity. 
   The invention also relates to a method of assembling a connector. The method includes providing a housing with at least one cavity, inserting at least one terminal fitting into the cavity, and engaging a lock formed in the cavity with the terminal fitting to lock the terminal fitting. The method also includes mounting a front wall on the front surface of the housing. The step of mounting the front wall on the housing may include mounting the front wall at a partial locking position, performing an electrical connection test and then moving the front wall to a final locking position so that a mating tab can be inserted into the cavity for connection with the terminal fitting. 
   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 front view of a connector according to a first embodiment of the invention when a front wall is at a full locking position. 
       FIG. 2  is a front view of the connector when the front wall is at a partial locking position. 
       FIG. 3  is an enlarged front view showing an essential portion when the front wall is at the full locking position. 
       FIG. 4  is an enlarged front view showing an essential portion when the front wall is at the partial locking position. 
       FIG. 5  is a section of the connector when the front wall is at the full locking position and connection with a tab is established. 
       FIG. 6  is a section of the connector when the front wall is at the partial locking position. 
       FIG. 7  is a section of the connector when the front wall is at the partial locking position and detection probes are brought into contact. 
       FIG. 8  is a front view of a female housing. 
       FIG. 9  is a top plan view of the female housing. 
       FIG. 10  is a side view of the female housing. 
       FIG. 11  is a front view of the front wall. 
       FIG. 12  is a rear view of the front wall. 
       FIG. 13  is a front view of a retainer. 
       FIG. 14  is a side view of the retainer. 
       FIG. 15  is a section of the retainer. 
       FIG. 16  is an exploded side view of a connector according to a second embodiment of the invention. 
       FIG. 17  is a front view of the connector showing a state where a front wall is mounted. 
       FIG. 18  is a front view showing a state before the front wall is mounted. 
       FIG. 19  is a bottom view showing a state before the front wall is mounted. 
       FIG. 20  is a section showing a state before the front wall is mounted. 
       FIG. 21  is a section showing a state where the front wall is mounted. 
       FIG. 22  is a front view of a retainer. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A female housing according to a first embodiment of the present invention is identified by the numeral  10  in  FIGS. 1 to 15 . The female housing  10  is connectable with a male housing (not shown). In the following description, a side to be connected with the male housing is referred to as the front. 
   The female housing  10  is made e.g. of a synthetic resin substantially into a block preferably having a wide cross section. As shown in  FIG. 8 , the female housing  10  is formed internally with cavities  11  at upper and lower stages. The cavities  11  penetrate the female housing  10  substantially in forward and backward directions FBD. Female terminal fittings  40  can be accommodated into the cavities  11  from behind, and front openings of the cavities  11  permit the passage of tabs  70  of male terminal fittings at least partly accommodated in the male connector housing. 
   Each female terminal fitting  40 , as shown in  FIG. 5 , is formed unitarily and has opposite front and rear ends. A main portion  41  is at the front end and a wire connection portion is at the rear end. The wire connection portion has a wire barrel  42  and an insulation barrel  43  that are configured to be crimped, bent or folded into connection with a wire W. The main portion  41  is formed into a box of substantially rectangular cross section by bending, folding and/or shaping an electrically conductive metal sheet in a width direction. More particularly, the main portion  41  has a ceiling plate  41 A, a bottom plate  41 B and left and right side plates  41 E, as shown in  FIG. 3 . A stabilizer  44  projects up from one of the side plates  41 E. The stabilizer  44  can slide in contact with an escaping groove (not shown) formed along one corner of the upper surface of each cavity  11  to prevent an improper (e.g. upside-down) insertion of the female terminal fitting  40  because of an unmatched positional relationship of the stabilizer  44  and the escaping groove when the female terminal fitting  40  is inserted improperly oriented (e.g. upside down). 
   A resilient contact  45  is cantilevered from the front of the ceiling plate  41 A and is bent back into the main portion  41 . The resilient contact piece  45  has an angled side view and is resiliently deformable up and down in a direction intersecting an inserting direction of the mating tab  70  into the main portion  41 . A contact point  45 A with the mating tab  70  projects at the tip of the resilient contact  45  to squeeze and contact the tab  70  in cooperation with a receiving portion  41  F formed inwardly on the bottom plate  41 B. 
   The base end of the resilient contact  45  is joined to the front end of the ceiling plate  41 A at a position deviated to one side (to left in  FIG. 3 ) from the widthwise center, and slants as it extends back. A tab insertion opening  41 G is formed at part of the front of the main portion  41  at a position immediately above the base end of the resilient contact  45  and hence toward one side from the widthwise center. A detecting plate  46  closes a remaining part of the front end of the main portion  41  near the tab insertion opening  41 G. The detecting plate  46  has a vertically long rectangular front view, and is formed by bending a forward projecting portion of the right side plate  41 E shown in  FIG. 3  inwardly at a substantially right angle. When the female terminal fitting  40  is viewed from the front, the base end of the resilient contact  45  is located adjacent to the detecting plate  46 . 
   As shown in  FIG. 5 , a lock  12  is formed unitarily at the upper surface of each cavity  11  of the female housing  10 . The lock  12  cantilevers substantially forward along the forward and backward directions FBD and is resiliently deformable up and down in a direction intersecting a mounting direction of the terminal fitting  40  into the cavity  11 . A locking projection  12 A extends from the free end of the lock  12  and projects towards the cavity  11 . A deformation space  13  is defined above the lock  12 . At least one mold-removal hole  14  is left in the front surface of the female housing  10  as the lock  12  is formed. More particularly, the mold removal hole  14  is before the lock  12  and the deformation space  13 , and communicates with the cavity  11 . The lock  12  interferes with the female terminal fitting  40  during insertion of the female terminal fitting  40  into the cavity  11 . As a result, the lock  12  is deformed up into the deformation space  13 . The lock  12  is restored resiliently when the female terminal fitting  40  is inserted properly so that the locking projection  12 A engages a locking hole  47  formed in the ceiling plate  41 A to retain the female terminal fitting  40 . 
   A lock arm  15  is formed at the widthwise center of the upper surface of the female housing  10 . The lock arm  15  cantilevers back substantially along the forward and backward directions FBD with the base end thereof supported on the front end of the upper surface of the female housing  10 . An operable portion  15 A is provided at or close to the free end of the lock arm  15  and a lock projection  15 B is formed at a substantially longitudinal middle position of the upper surface of the lock arm  15 . The lock projection  15 B can be engaged with the male connector housing to hold the housings together. 
   A slanted surface  15 E is defined on the lower side of the lock arm  15  behind the longitudinal middle and a rear area of the upper surface of the female housing  10  facing the slanted surface  15 E is lowered slightly as compared to a front area. Thus, a sufficient deformation space for the lock arm  15  is ensured between the rear area of the lock arm  15  and the rear area of the upper surface of the female housing  10 . Deformation spaces  13  for the locks  12  are formed inside the front area of the upper surface of the female housing  10  to reduce the height of the female housing  10 . 
   A turning preventing wall  16  projects on the upper surface of the female housing  10  and at least partly surrounds the operable portion  15 A of the lock arm  15 . The turning preventing wall  16  is substantially gate-shaped and has two legs  16 A connected with the opposite ends of the upper surface of the female housing  10  and a ceiling portion  16 B spanning between the legs  16 A. The operable portion  15 A is arranged inside the turning preventing wall  16 . The turning preventing wall  16  prevents the lock arm  15  from being turned up when the lock arm  15  gets caught by external matter such as by a looped wire W. As shown in  FIG. 9 , the ceiling portion  16 B of the turning preventing wall  16  is notched to form a operating hole  16 E so that a finger can push the operable portion  15 A. 
   As shown in  FIG. 10 , a retainer mount hole  17  is formed in three surfaces of the female housing  10  and extends from the bottom surface to the opposite side surfaces. The retainer mount hole  17  has a depth to communicate with the respective cavities  11 , thereby dividing the cavities  11  at the upper and lower stages into front and rear parts. The retainer mount hole  17  has inclined rear edges  17 A that incline up and to the front on the opposite side surfaces of the female housing  10 . Oblique finger placing projections  18  are formed at or close to the rear end of the bottom surface of the female housing  10  substantially continuous with the inclined edges  17 A. 
   Guide ribs  19  are on the opposite side surfaces of the female housing  10 . The guide ribs  19  extend substantially parallel with the inclined edges  17 A and partly cover the openings of the retainer mount hole  17 . Each guide rib  19  is an elongated plate with a first shorter side connected with the front upper end of the opening of the retainer mount hole  17  and with a second shorter side connected with a restricting wall  21 . The restricting wall  21  spans substantially horizontally between the second shorter side of the guide rib  19  and the front bottom end of the inclined edge  17 A. A guide hole  22  is defined between the guide rib  19  and the inclined edge  17 A. Locking projections  24  extend substantially in forward and backward directions FBD on recessed surfaces  23  slightly retracted from peripheral areas of the opposite side surfaces of the female housing  10  before the retainer mount hole  17 . 
   The connector further includes a retainer  90  made e.g. of a synthetic resin similar to the female housing  10 . The retainer  90  includes a retainer main body  92  that can fit into the retainer mount hole  17  and supporting plate  93  bulges out substantially forward from the bottom end of the retainer main body  92 . 
   The retainer main body  92  is formed with as many window frames  94  as the cavities  11  at each stage of the female housing  10 . The respective window frames  94  are formed to substantially align with the cavities  11  at the lower stage of the female housing  10 . The front opening edges of the respective window frames  94  are substantially vertical to conform to the rear opening edges of the front parts of the respective divided cavities  11 . The rear opening edges of the window frames  94  have an inclination substantially corresponding to the inclination of the front opening edges of the rear parts of the divided cavities  11 . 
   The retainer  90  is movable between a partial locking position and a full locking position. When the retainer  90  is at the partial locking position, the lower and upper surfaces of the respective window frames  94  are substantially at the substantially same heights as the bottom surfaces of the corresponding cavities  11  to permit insertion and withdrawal of the female terminal fittings  40 . On the other hand, if the retainer  90  is moved to the full locking position, end surfaces of the respective window frames  94  oppose rear edges of the main portions  41  of the female terminal fittings  40  to lock the female terminal fittings  40  doubly in cooperation with the locks  12 . Engaging projections  91  are formed substantially along the inclination of the rear surfaces of the respective window frames  94  on the opposite side surfaces of the retainer main body  92 . 
   The supporting plate  93  of the retainer  90  is dimensioned to substantially fully close the opening of the retainer mount hole  17  in the bottom surface of the female housing  10  when the retainer  90  is at the full locking position. Two standing plates  95  project substantially vertically from the opposite ends of the supporting plate  93 . The standing plates  95  are spaced apart sufficiently to hold the opposite recessed side surfaces  23  of the female housing  10 , and are deformable in and out to change a spacing therebetween. The rear edges of the standing plates  95  are arranged to extend substantially along the front edges of the guide ribs  19  of the female housing  10 , and the guide ribs  19  are held between the standing plates  95  and the engaging projections  91 . Engaging projections  96  are formed on the inner surfaces of the upper ends of the standing plates  95  to substantially face each other. 
   The engaging projections  96  of the retainer  90  contact the lower surfaces of the locking projections  24  of the female housing  10  when the retainer  90  is at the partial locking position to prevent any further oblique upward movement of the retainer  90 . Simultaneously, the engaging projections  91  contact the upper edges of the restricting walls  21  to prevent the retainer  90  from coming off. The engaging projections  96  move onto the locking projections  24  in the process of moving the retainer  90  to the full locking position and the standing plates  95  deform to widen the spacing therebetween. The standing plates  95  are restored towards their initial postures and the engaging projections  96  engage the upper surfaces of the locking projections  24  when the retainer  90  reaches the full locking position, thereby holding the retainer  90  at the full locking position. 
   As shown in  FIG. 8 , a mounting frame  27  is formed on the front surface of the female housing  10  and has a substantially gate-shape defined by opposite side walls  25  and an upper wall  26 . A substantially flat plate-shaped front wall  50  made e.g. of a synthetic resin is fit from below and along a mounting direction MD into the mounting frame  27  along the front surface of the female housing  10 . 
   As shown in  FIG. 11 , the front wall  50  is formed with as many tab insertion holes  51  as the respective cavities  11 . The tab insertion holes  51  are arranged along the width direction at upper and lower stages and can communicate with the corresponding cavities  11 . The tab insertion holes  51  are dimensioned to be held in sliding contact with the tabs  70  to guide the tabs  70  to the corresponding cavities  11 . The front wall  50  also is formed with jig insertion holes  52  that can communicate with the mold-removal holes  14 . The jig insertion holes  52  are arranged at upper and lower stages and have an offset positional relationship along the mounting direction MD with the respective tab insertion holes  51 . The jig insertion hole  52  at the left end in  FIG. 11  of the upper stage opens in the upper end of the front wall  50 . 
   As shown in  FIG. 12 , ribs  53  are formed substantially side by side on the rear surface of the front wall member  50  and extend substantially vertically along the mounting direction MD. The ribs  53  can be connected with partition walls  28  partitioning the cavities  11  in the female housing  10 . A base  54  bulges out backward from the bottom end of the rear surface of the front wall  50 , and the base ends of the vertical ribs  53  are coupled to the upper surface of this base  54 . 
   Two first latches  55  are formed at the opposite side edges of the front wall  50  at substantially the same height, and two second latches  56  are formed above and at a specified distance to the first latches  55 . The first and second latches  55 ,  56  have identical shapes and sizes. The latches  55 ,  56  have slanted upper surfaces  57  that incline down towards the projecting ends and slanted lower surfaces  58  that incline upward toward the projecting ends. 
   On the other hand, as shown in  FIG. 10 , two first receiving portions  31  are formed on the opposite side walls  25  of the mounting frame  27  at substantially the same height, and two second receiving portions  32  are formed at substantially the same height above and at a specified distance from the first receiving portions  31 . The receiving portions  31 ,  32  are rectangular holes of identical shape and size that penetrate the side walls  25  in a thickness direction and can receive the respective first and second latches  55 ,  56 . Front parts of the first and second receiving portions  31 ,  32  are partitioned by disengagement preventing walls  33  formed by thinning the outer surfaces of the side walls  25  to prevent front wall member  50  from coming off forward. 
   The front wall  50  is held at the partial locking position  1 P by resiliently fitting the second latches  56  into the first receiving portions  31  as shown in  FIG. 2  while being held at the full locking position  2 P by resiliently fitting the second latches  56  into the second receiving portions  32  and the first latches  55  into the first receiving portions  31 , as shown in  FIG. 1 . As a result, the front wall  50  is movable substantially up and down along the mounting direction MD between the partial locking position  1 P and the full locking position  2 P. In the process of moving the front wall  50  from the partial locking position  1 P to the full locking position  2 P, the second latches  56  move over partition walls  34  between the first and second receiving portions  31 ,  32  while resiliently pushing the partial walls  34  out. Thus, the first latches  55  move over end walls  35  below the first receiving portions  31  while pushing the end walls  35  out. The first and second latches  55 ,  56  can smoothly move over the partition walls  34  and the end walls  35  by bringing the slanted surfaces  57  as the upper surfaces of the first and second latches  55 ,  56  into sliding contact with the lower surfaces of the partition walls  34  and the end walls  35 . Likewise, in the process of moving the front wall  50  from the full locking position  2 P to the partial locking position  1 P, the first and second latches  55 ,  56  can move smoothly over the partition walls  34  and the end walls  35  by bringing the slanted lower surfaces  58  of the first and second latches  55 ,  56  into sliding contact with the upper surfaces of the partition walls  34  and the end walls  35 . 
   The front surface of the front wall  50  is substantially continuous and flush with the front surface of the mounting frame  27  and the lower surface of the front wall  50  is substantially continuous and flush with the bottom surface of the female housing  10  when the front wall  50  reaches the full locking position  2 P. Further, a guide hole  36  vertically penetrates the upper wall  26  of the mounting frame  27 . At least one pressing projection  59  is formed at the upper end as seen in the mounting direction MD of the front wall  50  and can fit into the guide groove  36 . The pressing projection  59  is fit into the guide groove  36  and the upper end is exposed at the upper surface of the female housing  10  when the front wall  50  reaches the full locking position  2 P, as shown in  FIG. 1 . The front wall  50  can be moved to the partial locking position  1 P by pressing this exposed upper end down in a direction substantially opposite to the mounting direction MD. 
   The tab insertion holes  51  communicate with the cavities  11  and the jig insertion holes  52  communicate with the mold-removal holes  14  when the front wall  50  reaches the full locking position  2 P. Accordingly, the tabs  70  can be inserted into the tab insertion holes  51  from the front in this state. Thus, the leading ends of the tabs  70  pass through the tab insertion holes  51  and enter the main portions  41  of the female terminal fittings  40  in the cavities  11  to contacting the resilient contacts  45  in the main portions  41  and to establish electrical connection. An unlocking jig (not shown) for disengaging the lock  12  from the female terminal fitting  40  can be inserted into the jig insertion hole  52  from the front so that the leading end of the jig enters the mold-removal hole  14  to contact with the front surface of the locking projection  12 A at the leading end of the lock  12 . As a result, the lock  12  can be pushed up towards the deformation space  13  in the unlocking direction. 
   The tab insertion holes  51  are displaced from the cavities  11  when the front wall  50  is at the partial locking position  1 P shown in  FIG. 2 . Thus, the tabs  70  cannot enter the main portions  41  of the female terminal fittings  40  even if inserted into the displaced tab insertion holes  51 . Further, the front lower parts of the detecting plates  46  of the female terminal fittings  40  face the jig insertion holes  52 . Thus, detection probes  60  can be inserted into the jig insertion holes  52  from the front, and leading ends of the probes  60  contact the front lower parts of the detecting plates  46 . Whether the female terminal fittings  40  are inserted properly in the cavities  11  can be detected based on electrical connections between the probes  60  and the detecting plates  46 . 
   The front wall  50  first is fit loosely into the mounting frame  27  from below and along the mounting direction MD. In this state, the front  50  is pushed in the mounting direction MD to let the second latches  56  resiliently move over the end walls  35  of the female housing  10  and to fit the second latches  56  into the first receiving portions  31 . Thus, the front wall  50  is at the partial locking position  1 P, as shown in  FIG. 2 . The front wall  50  can be moved towards the full locking position  2 P as shown in  FIG. 1  by pushing the front wall  50  up in the mounting direction MD to fit the second latches  56  into the second receiving portions  32  and to fit the first latches  55  into the first receiving portions  31 . Subsequently or concurrently, the retainer  90  is set in the female housing  10  and held at the partial locking position. 
   The female terminal fitting  40  then is inserted into the cavity  11  from behind and is locked by the lock  12 . At this time, a part of the rear surface of the front wall  50  around the tab insertion hole  51  faces the front edge of the female terminal fitting  40 . After the insertion of all the female terminal fittings  40  is completed, the retainer  90  is pushed obliquely up and forward in the inserting direction to the full locking position for doubly locking the female terminal fittings  40 . In this state, the tab insertion holes  51  of the front wall  50  substantially align with the tab insertion openings  41 G of the main portions  41  of the female terminal fittings  40 , and the jig insertion holes  52  of the front wall  50  communicate with the mold-removal holes  14  of the female housing  10 . 
   The male connector housing then is connected from the front so that the tabs  70  of the male terminal fittings pass through the tab insertion holes  51  of the front wall  50  and enter the main portions  41  of the respective female terminal fittings  40 , as shown in  FIG. 5 . The tabs  70  could enter at positions displaced from proper position due to an error in positioning the two housings. However, the displaced tabs  70  will contact the opening edges of the tab insertion holes  51 . Accordingly, the erroneous entrance of the tabs  70  into the mold-removal holes  14  can be prevented. In addition, slanted surfaces  51 A for guiding the tabs  70  are formed around the tab insertion holes  51  in the front surface of the front wall  50 . Thus, the positions of the tabs  70  are corrected to guide the tabs  70  into the main portions  41  of the female terminal fittings  40 . 
   The retainer  90  is returned to the partial locking position or detached to remove the female terminal fittings  40 . An unlocking jig then is inserted through the jig insertion hole  52  from the front and enters the mold-removal hole  14  to bring the leading end of the jig into contact with the leading end of the lock  12 . As a result, the lock  12  can be deflected up towards the deformation space  13 . After being disengaged from the lock  12 , the female terminal fitting  40  is withdrawn. 
   To conduct an electrical connection test for the female terminal fittings  40 , the front wall  50  is moved to the partial locking position  1 P as shown in  FIG. 6 . At the partial locking position  1 P, the jig insertion holes  52  of the front wall  50  align with the front lower parts of the detecting plates  46  of the female terminal fittings  40  in the cavities  11 . As shown in  FIG. 7 , the detection probes  60  then are inserted through the jig insertion holes  52  of the front wall  50  from the front and contact with the detecting plates  46  to conduct the electrical connection test. 
   The tab insertion holes  51  are offset from the centers of the tab insertion openings  41 G of the main portions  41  of the female terminal fittings  40  in the cavities  11  when the front wall  50  is at the partial locking position  1 P. Accordingly, detection probes  60  that are inserted inadvertently into the tab insertion holes  51  of the front wall  50  in this state will contact the front edges of the terminal fittings or the front surface of the female housing  10  and cannot enter the main portions  41 . As a result, the detection probes  60  cannot contact the resilient contacts  45 . 
   As described above, the front wall  50  prevents erroneous insertion of the tabs  70 . Thus, this construction is particularly effectively for small-size connectors where such an erroneous insertion of the tabs  70  is likely to occur. 
   Further, the detection probes  60  for electrical connection test pass through the jig insertion holes  52  of the front wall  50  at the partial locking position  1 P and contact parts of the female terminal fittings  40  different from the resilient contacts  45 . Thus, the electrical connection test can be conducted without touching the resilient contacts  45  and deformation of the resilient contacts  45  can be prevented during the electrical connection test. The detection probes  60  for electrical connection test could be inserted into the tab insertion holes  51 , but they cannot enter the main portions  41 . Thus, contact of the detection probes  60  and the resilient contacts  45  is prevented. 
   The jig insertion holes  52  function as through holes for permitting the unlocking jig to reach the lock  12  at the full locking position  2 P of the front wall  50  while functioning as through holes for permitting the detection probes  60  to reach the front lower parts of the detecting plates  46  at the partial locking position  1 P of the front wall  50 . Thus, it is not necessary to form two kinds of such through holes, and the construction of the front wall  50  can be simplified. 
   The detection probes  60  contact the detecting plates  46  of the female terminal fittings  40  during the electrical connection test. Thus, large contact areas with the detection probes  60  can be ensured, thereby improving the reliability of the electrical connection test. 
   A second embodiment of the invention is described with reference to  FIGS. 16 to 22 . A connector of this embodiment has a female housing  10  connectable with a male connector housing (not shown), and a front wall  50  is coupled unitarily to the female housing  10  via one or more hinges  30  and is mountable on the front surface of the female housing  10 . Thus, the second embodiment differs from the first embodiment in that the front wall member  50  is unitary to the female housing  10 . In the following description, parts that are the same as or similar to the first embodiment are identified by the same reference numerals, but are not described again. 
   A mounting frame  27  projects from the front surface of the female housing  10 . The mounting frame  27  is gate-shaped and has opposite side walls  25  and an upper wall  26  formed at the front surface of the female housing  10 . The front wall  50  is made e.g. of a synthetic resin into a substantially flat plate, and is mounted onto the mounting frame  27  by being rotated. 
   The front wall  50  is formed to be unitary to the female housing  10  via hinges  30 . As shown in  FIG. 19 , the hinges  30  are resiliently deformable and are formed between pairs of slits  29  having open front ends at two positions of a bottom wall  10 A of the female housing  10  near the opposite sides. The lower surfaces of the hinges  30  are substantially continuous and flush with the bottom surface of the female housing  10 , and the upper surfaces thereof are substantially at the bottoms of bored portions  10 B formed at intermediate positions of the bottom wall  10 A of the female housing  10  with respect to thickness direction as shown in  FIG. 20 . Therefore, the hinges  30  are made thin to ensure flexible resilient deformations. 
   The front wall  50  is supported rotatably by both hinges  30  by being connected to ends of the hinges  30  at two bottom positions near the opposite sides. Accordingly, the connected positions of the front wall  50  and the hinges  30  are more backward than the front end of the female housing  10  including the mounting frame  27 , as shown in  FIG. 20 . 
   The front wall  50  is displaceable between a mounted position MP where the front wall  50  is mounted on the front surface of the female housing  10  and an unmounted position UMP where the front wall  50  is distanced from the front of the female housing  10  by being rotated about the hinges  30 . 
   As shown in  FIG. 20 , the front wall  50  can be molded while being at an initial position IP where the front wall  50  assumes a horizontal posture by being rotated about the hinges  30  by about 90° in the opening direction from the mounted position MP and the tab insertion holes  51 , the jig insertion holes  52  and the retainer mount holes  17  in the bottom surface of the female housing  10  are open in the same direction. Accordingly, the connector assumes the state shown in  FIG. 20  when being molded. Therefore, upon molding the front wall  50 , the tab insertion holes  51  and the jig insertion holes  52  can be formed using a mold for forming the retainer mount hole  17  (mold not shown) slidable along vertical direction in  FIG. 20 . 
   As shown in  FIGS. 17 and 21 , the front wall  50  fits into the mounting frame  27  at the mounted position MP. The front wall  50  is permitted to make substantially only rotary movements RM about the hinges  30 . If the unmounted position UMP is a rotation starting position, the mounted position MP is a rotation ending position. Movement other than the rotary movement RM is not permitted. Hence, movement parallel to the mounting frame  27  towards the front of the female housing  10  after the rotation of the front wall  50  is not permitted. In this case, the hinges  30  deal with the rotation RM of the front wall  50  by resiliently deforming the connected portions with the front wall  50 . 
   A lock piece  55  projects in a rear-half of the thickness of the front wall  50  at an intermediate position of the upper end of the front wall  50  (e.g. above two middle jig insertion holes  52  at the upper stage). The lock piece  55  has a wide shape with a base end connected with the vertical ribs  53 . A front surface thereof is a substantially vertical locking surface  55 A and the rear surface thereof is a slanted guide surface  55 B inclined up towards the front. 
   The upper wall  26  of the mounting frame  27  has a receiving portion  71  in the form of a wide slit formed by recessing an intermediate portion of the base end of the lock arm  15 . The receiving portion  71  is open in the rear surface of the base end of the lock arm  15  and in the lower surface of the upper wall  26 . The lock piece  55  of the front wall  50  is fit resiliently into the receiving portion  71  when the front wall  50  reaches the mounted position MP, so that the front wall  50  can be retained. The front surface of the receiving portion  71  is a substantially vertical engaging surface  71 A to ensure a strong locking force in cooperation with the locking surface  55 A of the lock piece  55 . The guide surface  55 B of the lock piece  55  slides in contact with the lower surface of the upper wall  26  before the front wall  50  reaches the mounted position MP. Thus, the smooth rotation RM of the front wall  50  is ensured. 
   When the front wall  50  reaches the full locking position MP, the upper end and the opposite sides thereof are covered by the mounting frame  27  as shown in  FIG. 17 , the tab insertion holes  51  of the front wall  50  communicate with the cavities  11 , and the jig insertion holes  52  communicate with the mold-removal holes  14 . Accordingly, tabs can be inserted into the tab insertion holes  51  from the front in this state. Thus, the leading ends of the tabs pass through the tab insertion holes  51  and enter the main portions  41  of the female terminal fittings  40  in the cavities  11  to contact the resilient contacts  45  in the main portions  41  to establish electrical connections therebetween. On the other hand, an unlocking jig (not shown) for disengaging the lock  12  from the female terminal fitting  40  can be inserted into the jig insertion hole  52  from the front. Thus, the leading end of the jig enters the mold-removal hole  14  through the jig insertion hole  52  to contact the front surface of the locking projection  12 A at the leading end of the lock  12 . As a result, the lock  12  can be pushed up towards the deformation space  13  in the unlocking direction. 
   The front wall  50  at the unmounted position UMP is rotated about the hinges  30  in closing direction RD (direction of arrow in  FIG. 20 ) to reach the mounted position MP. Thus, the front wall  50  is mounted to the female housing  10  through a one-touch operation because of the resilient engagement of the lock piece  55  and the receiving portion  71 . At the mounted position MP, the side edges of the front wall  50  are covered by the mounting frame  27  so that the front wall  50  is hidden behind the mounting frame  27  when viewed from the side or above. 
   Subsequently or concurrently, the retainer  90  is set in the female housing  10  and held at the partial locking position. The female terminal fitting  40  is inserted into the cavity  11  from behind to a proper insertion position and is locked by the lock  12 . At this time, a part of the rear surface of the front wall  50  around the tab insertion hole  51  functions as a front stop for the female terminal fitting  40  by being opposed to the front of the female terminal fitting  40 . After the insertion of all the female terminal fittings  40  is completed, the retainer  90  is moved obliquely up and forward to the full locking position, thereby doubly locking the female terminal fittings  40 . 
   In this state, the tab insertion holes  51  of the front wall  50  substantially align with the front openings of the main portions  41  of the female terminal fittings  40  and the jig insertion holes  52  of the front wall  50  communicate with the mold-removal holes  14  of the female housing  10  as shown in  FIG. 21 . 
   A mating male connector housing can be connected from front so that the tabs of the male terminal fittings pass through the tab insertion holes  51  of the front wall  50  and enter the main portions  41  of the female terminal fittings  40 . The tabs may try to enter positions deviated from proper positions e.g. due to a positioning error between the two housings. Thus, the tabs are displaced from the tab insertion holes  51  of the front wall  50  to contact the opening edges of the tab insertion holes  51 . Accordingly, the erroneous insertion of the tabs into the mold-removal holes  14  is prevented. Further, slanted surfaces  51 A are formed in the front surface of the front wall  50  around the tab insertion holes  51  for guiding the tabs. Thus, displacements of the tabs are corrected to guide the tabs into the main portions  41  of the female terminal fittings  40 . 
   Upon withdrawing the female terminal fitting  40 , the unlocking jig is inserted into the jig insertion hole  52  from the front after the retainer  90  is returned to the partial locking position or detached from the female housing  10 . Then, the unlocking jig is inserted into the mold-removal hole  14  through the jig insertion hole  52  to bring the leading end thereof into contact with the leading end of the lock  12 . The lock  12  can be displaced up toward the deformation space  13 . The female terminal fitting  40  is pulled out after being disengaged from the lock  12 . 
   As described above, the front wall  50  is unitary with the female housing  10  and the hinges  30 . Thus, it is not necessary to separately form the front wall  50  and the female housing  10 , thereby reducing the number of parts and making it easier to mold the connector. 
   Further, since the front wall  50  is rotatable about the hinges  30  and the rotation ending position thereof along closing direction is the mounted position MP on the female housing  10 , the front wall  50  can be mounted on the front surface of the female housing  10  through one movement, improving mounting operability. 
   The position of the front wall  50  reached by rotating the front wall  50  by about 90° in opening direction from the mounted position MP is the initial position (IP) and the tab insertion holes  51  and the retainer mount hole  17  are open in the substantially same direction at this initial position IP. Thus, the mold can be simplified by setting the posture of the housing at the time of molding to the one where the front wall  50  is at the initial position IP. 
   When the front wall  50  is mounted on the front surface of the female housing  10 , the side edges thereof are protected by the mounting frame  27 . Thus, the front wall  50  will not be detached inadvertently from the front surface of the female housing  10  due to the intrusion of an external matter. 
   The invention is not limited to the above described and illustrated embodiments. 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 front lower part of the detecting plate serves as the detecting portion for the electrical connection test in the first embodiment, a front upper part of the detecting plate or a part of the main portion except the resilient contact piece may serve as the detecting portion for the electrical connection test according to the present invention. 
   Although the hinges are formed to have a rigidity to be substantially unfoldable in the second embodiment, they may be formed to have such a length as to be foldable according to the present invention. 
   Although two hinges are provided in the second embodiment, one, three or more hinges may be provided according to the present invention. 
   Although the connector into which the retainer is mounted is shown in the first and second embodiments, the invention is also applicable to connectors with no retainer.