Patent Publication Number: US-7722381-B2

Title: Connector

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to a connector. 
   2. Description of the Related Art 
   Japanese Unexamined Patent Publication No. 2001-307819 discloses a connector with two housings that are connectable with each other. One housing has a tubular receptacle and the other has a tower with cavities for accommodating terminal fittings. Ribs are provided on the inner peripheral surface of the receptacle and project towards the outer surface of the tower to prevent the tower from shaking in the receptacle. Japanese Unexamined Patent Publication No. 2003-229195 discloses another connector with a cap-shaped front holder mounted on the tower. A front wall of the holder forms front walls of the cavities. 
     FIG. 7  herein shows a connector with a front holder  1  that can be fit on a tower  2 , and then fit in a receptacle  3 . A clearance is defined between the inner peripheral surface of the receptacle  3  and the outer peripheral surface of the tower  2  at least by the thickness of a surrounding wall of the front holder  1 . Ribs  4  project from the inner peripheral surface of the receptacle  3  and have a projecting distance sufficient to fill up the clearance. However, the rib  4  becomes weaker as the projecting distance becomes large. 
   The invention was developed in view of the above situation, and an object thereof is to prevent a tower and a receptacle from shaking relative to each other without increasing a projecting distance of shake preventing projections in the case where the receptacle is fit on a tower having a front holder mounted thereon. 
   SUMMARY OF THE INVENTION 
   The invention relates to a connector with first and second housings that are connectable with each other. The first housing has a tubular receptacle and the second housing has a tower with at least one cavity for accommodating at least one terminal fitting. A front holder is mountable on the tower from the front and has a front wall. A surrounding wall projects from the peripheral edge of the front wall for covering at least part of the outer peripheral surface of the tower. The receptacle is fit from the front onto the tower while the front holder is mounted thereon. 
   Outer projections are provided on the outer peripheral surface of the surrounding wall and project towards the inner peripheral surface of the receptacle to substantially fill a clearance between the outer peripheral surface of the surrounding wall and the inner peripheral surface of the receptacle. Inner projections are provided on the inner circumferential surface of the surrounding wall and project towards the outer circumferential surface of the tower to substantially fill a clearance between the inner peripheral surface of the surrounding wall and the outer circumferential surface of the tower. The projections prevent the front holder and the tower from shaking in the receptacle. Additionally, the projections project from both the outer and inner peripheral surfaces of the surrounding wall of the front holder. Thus, projecting distances of the outer and inner projections are reduced and the strengths of the outer and inner projections are greater than shake preventing projections that project from only one of the receptacle and the tower. 
   The outer projections and the inner projections preferably are aligned respectively with one another with the surrounding wall therebetween. Thus, rigidity is improved in parts of the surrounding wall where the outer and inner projections are arranged to prevent deformation of these parts of the surrounding wall when subjected to an external force. 
   The contact position of mating terminal fittings could displace and impair connection reliability if the tower and the receptacle shake relative to one another. Accordingly, the outer projections or the inner projections preferably are arranged at substantially the same position as the contact position of the terminal fittings with respect to the width direction. Thus, loose movements of the tower in the receptacle are suppressed at a position close to the contact position of the both terminal fittings. Therefore, the connection reliability of the terminal fittings is maintained. 
   The projecting distance of the outer projections preferably is smaller than that of the inner projections. 
   At least one front-stop wall for the terminal fitting preferably is formed for the cavity. 
   An opening edge of a part of a tab insertion opening preferably is formed in the front-stop wall, and a slanted surface for guiding the male tab preferably is formed at the front surface of the opening edge. 
   These and other features of the invention will become more apparent upon reading the following detailed description of preferred embodiments and accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a front view of a female housing before a front holder is mounted in one embodiment. 
       FIG. 2  is a vertical section showing an essential portion of both female and male housings in a connected state. 
       FIG. 3  is a plan view of the female housing. 
       FIG. 4  is a front view of the front holder. 
       FIG. 5  is a rear view of the front holder. 
       FIG. 6  is a plan view of the front holder. 
       FIG. 7  is a section schematically showing a prior art. 
   

   DETAILED DESCRIPTION OF THE PREFERRED 
   A connector in accordance with the invention is described with reference to  FIGS. 1 to 6 . The connector of this embodiment is a fluid- or watertight connector with female and male housings  10 ,  60  that are connectable with each other. In the following description, ends of the housings  10 ,  60  to be connected are referred to as the front ends concerning forward and backward directions FBD, and reference is made to  FIG. 1  concerning vertical direction. 
   The male housing  60  is made e.g. of a synthetic resin and, although not shown in detail, includes a substantially tubular receptacle  61 , as shown in  FIG. 2 , in which male tabs (not shown) project. A lock  62  projects in a widthwise intermediate position of the upper wall of the receptacle  61  and protection walls  63  project from the upper wall of the receptacle  61  at the opposite sides of the lock  62 . Guide ribs  64  stand near the outer sides of the protection walls  63 . 
   The female housing  10  is made e.g. of a synthetic resin and has a tower  11  capable of accommodating female terminal fittings (not shown). A fitting tube  12  surrounds the tower  11 , as shown in  FIG. 1 . The female housing  10  further includes a front holder  13  to be mounted on the tower  11  from the front. Cavities  14  are arranged substantially in a transverse row and penetrate the tower  11  in forward and backward directions FBD. The terminal fittings are insertable into the cavities  14  from behind. Although not shown, the terminal fittings are crimped, bent or folded into connection with respective ends of wires preferably to which sealing members are mounted. 
   A pivotally displaceable resilient lock arm  15  is coupled to the upper wall of the tower  11  via a support  16 . As shown in  FIG. 3 , the lock arm  15  extends in forward and backward directions FBD, and a lock groove  17  is formed in a widthwise intermediate position thereof. The lock arm  15  moves onto the lock  62  and is displaced pivotally about a center on the support  16 . The lock  62  aligns with the lock groove  17  when the housings  10 ,  60  are connected properly, and the lock arm  15  resiliently restores so that the lock arm  15  engages the lock  62  to hold the two housings  10 ,  60  together. 
   A bulge  18  extends up and out on the upper wall of the fitting tube  2  and an accommodation space for the lock arm  15  is defined inside the bulge  18 . A rearwardly open escaping recess  19  is formed in the bulge  18 , and the lock arm  15  is exposed through the escaping recess  19 . Receiving grooves  21  extend in forward and backward directions FBD in the inner surface of the fitting tube  12  and receive the guide ribs  64  of the receptacle  61 . 
   Locks  22  extend substantially along inner walls of the cavities  14  in the tower  11 . Each lock  22  is cantilevered forward from a rear end that is connected with the inner wall of the cavity  14 , and is resiliently deformable up and down in a direction intersecting an insertion direction of the terminal fittings into the cavities  14 . A locking projection  23  is formed near the free front end of the lock  22  and projects towards the cavity  14 . Mold removal spaces  24  are left in the front wall of the tower  11  as the locks  22  are formed, and front-stop walls  25  for the terminal fittings are formed for the respective cavities  14  adjacent to the mold removal spaces  24 . Upper parts of the terminal fittings contact the rear surfaces of the front-stop walls  25 . Each front-stop wall  25  has a tab insertion opening  26 , and a slanted surface  27  is formed at the front surface of the opening edge for guiding the male tab. 
   The outer peripheral surface of the tower  11  is recessed slightly to form a facing surface to be covered by the surrounding wall  32  of the front holder  13 , and a seal (not shown) made of resilient material (such as rubber or gelatinous material) is mounted to a rear part of the facing surface. The seal is sandwiched in forward and backward directions FBD between the rear end of the front holder  13  and a step formed in the tower  11 . The seal  15  closely contacts the inner peripheral surface of the receptacle  61  and the outer peripheral surface of the tower  11  when the housings  10 ,  60  are connected to provide fluid- or watertight sealing between the housings  10 ,  60 . 
   The front holder  13  is made e.g. of a synthetic resin and has a front wall  31  for covering the front of the tower  11  to form at least part of front ends of the cavities  14 . The surrounding wall  32  projects back from the peripheral edge of the front wall  31  and covers the outer peripheral surface of the tower  11 , as shown in  FIGS. 4 to 6 . The front wall  31  has a wide rounded shape in front view, and windows  33  are arranged transversely in the upper part of the front wall  31  in conformity with the cavities  14 . The windows  33  receive the respective front-stop walls  25  of the tower  11 . Edges of the windows  33  in the front wall  31  are cut to form the lower parts of the tab insertion openings  26 , and slanted surfaces  27  are formed at the front surfaces of the opening edges for guiding the male tabs. 
   The tab insertion openings  26  of the front holder  13  and of the front-stop walls  25  become substantially continuous in the circumferential direction, as shown in  FIG. 2 , when the front holder  13  is mounted properly on the tower  11 , and the slanted surfaces  27  extend continuously around the tab insertion openings  26 . Jig insertion openings  34  are formed in the front wall  31  of the front holder  13  adjacent the respective windows  33  and can receive a jig for canceling the locked state by the lock  22 . The mold removal spaces  24  of the tower  11  are at least partly inside the jig insertion openings  34 , and the leading ends of the locks  22  can be seen through the jig insertion openings  34 . The jig can be inserted into the jig insertion opening  34  from the front so that the leading end of the jig is brought into hooking engagement with the leading end of the lock  22 . The jig then is levered forcibly to deform the lock  22  in an unlocking direction and to cancel the locked state of the lock  22 . 
   A deformation preventing portion  35  projects back from the rear surface of the front wall  31  of the front holder  13  at a position below the respective window holes  33  and extends substantially in a width direction WD. The deformation preventing portion  35  projects at least partly into the mold removal spaces  24  of the tower  11  and enters deformation spaces for the locks  22  to hinder deformation of the locks  22  when the front holder  13  is mounted properly. Accordingly, the properly inserted terminal fittings are locked primarily in the cavities  14  by the locks  22  and are locked secondarily by the deformation preventing portion  35  to achieve double locking. 
   The surrounding wall  32  of the front holder  13  has two opposed wide planar panels  36  and two opposed arcuate panels  37  that extend between opposite sides of the planar panels  36 . The planar panels  36  have a thickness substantially equal to the height of the step of the tower  11  and extend straight in the width direction WD. Two locking arms  38  project in at intermediate height positions of the arcuate panels  37 . The locking arms  38  are resiliently deformable in and out, and hold the front holder  13  at a partial locking position and a full locking position on the tower portion  11  by engaging locking areas of the tower  11 . The front wall  31  is spaced forward from the front surface of the tower  11  when the front holder  13  is at the partial locking position and the deformation preventing portion  35  is retracted from the deformation spaces for the locks  22 . Thus, the locks  22  can deform and the terminal fittings can be inserted into the cavities  14 . On the other hand, the front wall  31  contacts the front surface of the tower  11  and the deformation preventing portion  35  enters the deformation spaces for the locks  22  from the front when the front holder  13  is pushed from the partial locking position to the full locking position. Thus, the locks  22  cannot deform and the terminal fittings are locked doubly. In other words, the front holder  13  also functions as a retainer. 
   Inner projections  43  project in from spaced apart positions on the inner peripheral surface of the surrounding wall  32  of the front holder  13 . Outer projections  45  project out from spaced apart positions on the outer peripheral surface of the surrounding wall  32  of the front holder  13 . The inner and outer projections  43 ,  45  are substantially flat trapezoidal ribs that extend in forward and backward directions FBD over substantially the entire length of the surrounding wall  32 , as shown in  FIG. 6 . The inner and outer projections  43 ,  45  have small projecting distances, and the projecting distance of the outer projections  45  is smaller than that of the inner projections  43 . 
   Two upper inner projections  43  and two lower inner projections  43  are arranged substantially symmetrically on the planar panels  36  of the surrounding wall  32  at opposite sides of the widthwise centers, and left and right inner projections  43  are arranged substantially in the centers of the arcuate panels  37  of the surrounding wall  32  in height direction. The outer projections  45  are arranged similar to the inner projections  43  and have a substantially back-to-back relationship with the inner projections  43  with the surrounding wall  32  therebetween. The inner and outer projections  43 ,  45  provided on the wide planar panels  36  are arranged at substantially the same positions as the widthwise centers of the inner two cavities  14  with respect to the width direction WD when the front holder  13  is in its mounted state. Thus, the inner projections  43  on the wide planar panels  36  can be seen through the windows  33  from the front. 
   The terminal fittings are inserted into the cavities  14  of the tower  11  from behind with the front holder  13  held at the partial locking position. As a result, the locks  22  engage and hold the terminal fittings that have been inserted properly. The front holder  13  then is pushed to the full locking position. As a result, the deformation preventing portion  35  of the front holder  13  prevents deformation of the locks  22  to lock the terminal fittings redundantly. The leading end surfaces of the inner projections  43  of the surrounding wall  32  contact the outer peripheral surface of the tower  11  (contact state is shown in  FIG. 2 ) when the front holder  13  reaches the full locking position. 
   The tower  11  having the front holder  13  mounted thereon can be fit into the mating receptacle  61  to a proper depth. As a result, the male tabs in the receptacle  61  enter the cavities  14  through the tab insertion openings  26  and connect electrically with the terminal fittings in the cavities  14 . At this time, the terminal fittings and the mating male tabs have their contact positions substantially in the widthwise centers of the respective cavities  14 , and these widthwise centers of the cavities  14  are at substantially the same positions as the widthwise centers of the locks  22  with respect to the width direction WD. The leading end surfaces of the outer projections  45  of the surrounding wall  32  contact the inner peripheral surface of the receptacle  61  (contact state is shown in  FIG. 2 ) when the two housings  10 ,  60  are connected properly. 
   The terminal fittings and the male tabs could slide against each other and displace their connection positions within the range of a clearance between the receptacle  61  and the tower  11 , if the entire connector is vibrated while the housings  10 ,  60  are connected. This sliding movement could result in an unreliable connection between the terminal fittings and male tabs. However, the front holder  13  is interposed between the receptacle  61  and the tower  11 , and clearances to the outer peripheral surface of the tower  11  are filled by the inner projections  43  on the inner peripheral surface of the surrounding wall  32  of the front holder  13 . Similarly, clearances to the inner peripheral surface of the receptacle  61  are filled by the outer projections  45  on the outer peripheral surface of the surrounding wall  32  of the front holder  13 . Thus, loose movements of the front holder  13  and the tower  11  in the receptacle  61  are prevented, and relative positions of the receptacle  61  and the tower  11  are kept constant to avoid sliding movements of the terminal fittings. 
   The inner and outer projections  43  and  45  on the front holder  13  prevent the front holder  13  and the tower  11  from shaking in the receptacle  61 . More particularly, the front holder  13  is interposed between the receptacle  61  and the tower  11  and the clearances between the receptacle  61  and the tower  11  are filled substantially by the inner and outer projections  43  and  45  projecting from the inner and outer peripheral surfaces of the front holder  13 . Thus, as compared to the case where shake preventing projections project from only one of the receptacle  61  and the tower  11  toward the other, the projecting distances of the inner and outer projections  43  and  45  are reduced remarkably. As a result, the inner and outer projections  43  and  45  are stronger and surface sinks or the like during the molding can be prevented. 
   The inner and outer projections  43  and  45  are arranged to have a substantially back-to-back relationship (e.g. radial alignment) with the surrounding wall  32  therebetween. Thus, rigidity is improved in these parts of the surrounding wall  32 , and the surrounding wall  32  is less likely to deform plastically upon the exertion of an external force. 
   The inner and outer projections  43 ,  45  on the wide planar panels  36  of the surrounding wall  32  of the front holder  13  are arranged at substantially the same positions as the widthwise centers of the cavities  14  with respect to the width direction WD and substantially at the contact positions of the terminal fittings. Thus, loose movements of the tower  11  in the receptacle  16  can be suppressed at positions close to the contact positions of the both terminal fittings to maintain the connection reliability of the both terminal fittings. 
   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. 
   The front holder has the deformation preventing portion in the foregoing embodiment and functions as a retainer. However, the front holder may only function to form part of the front surface portions of the cavities without including the deformation preventing portion. 
   The inner and outer projections are ribs that extend substantially over the length of the surrounding wall of the front holder in the foregoing embodiment. However, the inner and outer projection may have short lengths in forward and backward directions FBD according to the invention. 
   The inner and outer projections are in back-to-back relationship in the foregoing embodiment. However, they may be displaced in the width direction WD with the surrounding wall therebetween. 
   Inner and outer projections are arranged substantially at the contact positions of the terminal fittings with respect to the width direction WD in the foregoing embodiment. However, only the inner or the outer projections may be arranged at the contact positions of the both terminal fittings with respect to the width direction according to the invention.