Patent Publication Number: US-6702626-B2

Title: Connector

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a connector provided with a retainer for locking terminal fittings. 
     2. Description of the Related Art 
     Japanese Unexamined Utility Model Publication No. 6-58570 discloses a known connector with a housing and a retainer that is mounted on the housing for movement from a partial mounting position to a full locking position. Terminal fittings can be inserted into the housing and partially locked when the retainer is in the partial mounting position. The retainer then is pushed to the full locking position for doubly locking terminal fittings. 
     The retainer and the housing have means for locking the retainer at the partial locking position and at the full locking position. Specifically, the retainer has a resilient locking piece that extends parallel to the pushing direction of the retainer from the partial locking position to the full locking position. A partial locking projection is formed at a leading end of the resilient locking piece and a full locking projection is formed more toward the base end of the resilient locking piece than the partial locking projection. The housing is formed with one fastening projection common to both partial and full locking projections. 
     The fastening projection is held between the partial locking projection and the full locking projection when the retainer is in the partial locking position. The retainer then can be pushed to the full locking position. The pushing force causes the full locking projection to deform away from the fastening projection and then to move over the fastening projection. Thus, the resilient locking piece engages the fastening projection to prevent a returning movement of the retainer toward the partial locking position. 
     A jig can be used to return the retainer from the full locking position to the partial locking position so that the terminal fitting can be withdrawn from the housing. As a result, the resilient locking piece deforms and the full locking projection disengages from the fastening projection. The resilient locking piece is restored resiliently as the full locking projection moves over the fastening projection. As a result, the fastening projection is held between the full and partial locking projections and in the partial locking position. 
     An excessively large force must be exerted on the retainer during the retainer returning operation because of the need to disengage the full locking projection from the fastening projection and the need to deform the resilient locking piece against its resilient force. There is a possibility that the large force required to move the retainer back to the partial locking position will inadvertently drive the partial locking projection over the fastening projection. Thus, the retainer may come out of the housing. 
     The invention was developed in view of the above problem and an object thereof is to prevent a retainer from coming out of a housing when the retainer is moved from a full locking position to a partial locking position. 
     SUMMARY OF THE INVENTION 
     The invention relates to a connector with a housing and a retainer that is moveable between first and second positions on the housing. At least one terminal fitting is inserted into the housing when the retainer is at the first position. The retainer then can be pushed to the second position to lock the terminal fitting in the housing. At least one resilient locking piece is cantilevered on the retainer and extends substantially in the pushing direction of the retainer from the first position to the second position. A first projection is near the free end of the resilient locking piece and a second projection is closer to the base end of the resilient locking piece. A fastening projection is formed in the housing and causes the resilient locking piece to deflect as the retainer is moved between the first and second positions. However, the resilient locking piece is restored resiliently when the retainer is in either of the first or second positions. Thus, the fastening projection engages the first projection when the retainer is in the first position and engages the second projection when the retainer is in the second position. A preventing means is provided for limiting deflection of the resilient locking piece when the first projection is engaged with the fastening projection, and hence prevents the retainer from disengaging from the housing in response to forces exerted for moving the retainer from the second position to the first position. 
     The fastening projection is engaged between the first and second projections to prevent loose movement of the retainer from the first position. 
     The second projection preferably is engageable with the free end side fastening projection to restrict the retainer from making a return movement toward the first position. 
     The preventing means prevents the free end of the resilient locking piece from displacing in response to forces in a direction for detaching the retainer from the housing. Thus, the resilient locking piece effectively is supported at both ends instead of being supported only at the base end. Accordingly, an apparent resilient force of the resilient locking piece is high, and deformation of the resilient locking piece is more difficult. The preventing means also prevents the first projection from moving over the fastening projection as the resilient locking piece is deformed resiliently. As a result, the retainer can be held at the first position. 
     Preferably, the second projection projects from the resilient locking piece less than the first projection. 
     The resilient locking piece is supported only at one end and is angularly displaceable. Thus, if the projecting distances of the first and second projections are equal, a degree of inclination of the resilient locking piece is larger when the first projection (closer to the free end) moves over the fastening projection than when the second projection (more distant from the free end) moves over the fastening projection. Therefore a larger force is required to move the retainer from the second position to the first position, and a design with equal projecting distances of the first and second projections is not preferable in view of operability. 
     In this respect, the projecting distance of the second projection is smaller than the projecting distance of the first projection according to the preferred embodiment. Thus, improved operability can be realized by reducing the force required to move the retainer between the second position and the first position while still preventing detachment of the retainer from the housing. 
     The free ends of the resilient locking pieces preferably are brought substantially into contact to restrict displacements of the free ends. 
     Two resilient locking pieces and two fastening projections preferably are provided and are substantially symmetrical. Thus, the free ends of the resilient locking pieces contact each other to restrict displacements of the free ends when the resilient locking pieces try to deform in directions that would disengage the first projections from the fastening projections with the retainer held at the first position. 
     The preventing means preferably is formed only by the resilient locking piece of the retainer, and the housing needs no preventing means. Thus, the housing has a simpler shape. 
     The second projections preferably are substantially symmetrically to each other. 
     The projecting distance of one of the second projections preferably is different than the projecting distance of the other of the second projections. 
     The retainer preferably is inserted into the housing at an angle to the inserting direction of the terminal fitting into the housing. 
     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 an exploded perspective view of a connector according to one embodiment of the invention. 
     FIG. 2 is a horizontal section showing a state where a retainer is detached from a housing. 
     FIG. 3 is a horizontal section showing an intermediate stage of mounting the retainer into the housing. 
     FIG. 4 is a horizontal section showing a state where the retainer is mounted at a partial locking position in the housing. 
     FIG. 5 is a horizontal section showing an intermediate stage of a movement of the retainer between the partial and full locking position. 
     FIG. 6 is a horizontal section showing a state where the retainer is mounted at a full locking position in the housing. 
     FIG. 7 is a horizontal section showing a state immediately after the retainer at the full locking position is moved to the partial locking position. 
     FIG. 8 is a front view of the retainer. 
     FIG. 9 is a front view of the connector. 
     FIG. 10 is a section along  10 — 10  of FIG.  9 . 
     FIG. 11 is a partial enlarged plan view of the retainer. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A connector according to the invention includes a housing  10 , a retainer  20  and terminal fittings  30 , as shown in FIGS. 1 to  11 . The housing  10  is made e.g. of a synthetic resin, and a sealing member  11  is mounted on the outer peripheral surface of the housing  10  for sealing a portion to be connected with a mating connector (not shown). Cavities  12  are formed at substantially a front half of the housing  10 , and a front holder  16  is fit to the front of the housing  10  for locking the sealing member  11  in the housing  10 . 
     The terminal fittings  30  are inserted into the cavities  12  from behind along an inserting direction ID. Each terminal fitting  30  has a first lock  31  engaged with a cavity lock  13  in the cavity  12  and a second lock  32  that faces an accommodation space  14  from the front when the terminal fitting  30  is inserted properly. 
     The accommodation space  14  extends transversely into the left side surface of the housing  10  substantially normal to the inserting direction ID and communicates with each cavity  12 . The retainer  20  is inserted into the accommodation space  14  from the left side of the housing  10  along a retainer inserting direction RID that is substantially normal to the inserting direction ID. A first fastening projection  15 F projects back from the front inner surface at the right end of the accommodation space  14 , and a second fastening projection  15 R projects forward from the rear inner surface. The first and second fastening projections  15 F,  15 R have substantially the same shape and dimensions and are substantially symmetric along forward and backward directions. Receiving surfaces  15   a  are formed at the left surfaces of the fastening projections  15 F,  15 R and extend substantially normal to the inserting direction RID of the retainer  20  into the accommodation space  14 , whereas slanted guide surfaces  15   b  are formed at the right surfaces thereof and are aligned oblique to the inserting direction RID of the retainer  20 . 
     The retainer  20  can be inserted into a partial locking or first position (see FIG. 4) in the accommodation space  14  of the housing  10  and then can be pushed further along the retainer inserting direction RID to a full locking or second position (see FIG.  6 ). The retainer  20  is made e.g. of a synthetic resin, and has a base  21  shaped to conform substantially to the outer side surface of the housing  10 , and an extending portion  22  that extends from the base  21  in substantially the same direction as the inserting direction RID into the accommodation space  14 . The extending portion  22  is a substantially flat plate and has terminal locks  23  on its lower surface for engaging the second locks  32  of the terminal fittings  30  in the cavities  12  when the retainer  20  is at the full locking position. The terminal locks  23  are retracted from the cavities  12  and outside the insertion paths of the terminal fittings  30  when the retainer  20  is at the partial locking position. Thus, the terminal fittings  30  can be inserted into and withdrawn from the cavities  12  along the inserting direction ID. 
     Front and rear resilient locking pieces  24 F,  24 R are formed at the end of the extending portion  22  remote from the base  21  for locking the retainer  20  at the partial locking position and at the full locking position. 
     The front resilient locking piece  24 F is at the front side of the extending portion  22  and extends substantially along the inserting direction RID of the retainer  20 . The front resilient locking piece  24 F is resiliently deformable along a deformation direction DD with a base end as a supporting point so that a free end  24   a  is displaced backward. Partial and full locking projections  25  and  26 F project forward from the front edge of the front resilient locking piece  24 F. 
     The partial locking projection  25  is at the free end  12   a  of the front resilient locking piece  24 F, and has a guide surface  25   a  and a locking surface  25   b . The guide surface  25   a  extends oblique to the inserting direction RID of the retainer  20  at the leading side of the partial locking projection  25  with respect to the inserting direction RID of the retainer  20 . The locking surface  25   b  extends substantially normal to the inserting direction RID of the retainer  20  at a side of the partial locking projection  25  that faces the base end of the front resilient locking piece  24 F. 
     The full locking projection  26 F is more toward the base end of the front resilient locking piece  24 F than the partial locking projection  25 , and a partial locking recess  27  (FIG. 4) is defined between the full locking projection  26 F and the partial locking projection  25  for receiving the fastening projection  15 F of the housing  10 . The full locking projection  26 F has a guide surface  26   a  and a locking surface  26   b . The guide surface  26   a  extends oblique to the inserting direction RID of the retainer  20  and is at a leading side of the full locking projection  26 F with respect to the inserting direction RID of the retainer  20 . The locking surface  26   b  is substantially normal to the inserting direction RID of the retainer  20  and is at a side of the full locking projection  26 F that faces the base end of the front resilient locking piece  24 F. A full locking surface  28  is formed more toward the base end than the full locking projection  26 F, and a full locking recess  29  is defined between the full locking projection  26 F and the full locking surface  28  for receiving the fastening projection  15 F of the housing  10 . 
     A projecting distance d of the full locking projection  26 F from the central axis of the extending portion  22  is less than the projecting distance D of the partial locking projection  25  from the central axis of the extending portion  22  (see e.g. FIG.  11 ). Thus, the front-end surface of the full locking projection  26 F is located more backward than that of the partial locking projection  25  with respect to the inserting direction ID of the terminal fittings  30 . 
     The rear resilient locking piece  24 R also extends substantially along the inserting direction RID of the retainer  20 , but along the rear side of the extending portion  22 . The rear resilient locking piece  24 R is resiliently inclinable with a base end as a supporting point such that a free end  24   a  is displaced forward toward the first resilient locking piece  24 F. The second resilient locking piece  24 R has partial and full locking projections  25  and  26 R that project back with respect to the inserting direction ID of the terminal fittings  30  from the rear edge of the rear resilient locking piece  24 R. 
     The partial locking projection  25  is at the free end  12   a  of the rear resilient locking piece  24 R, and has a guide surface  25   a  and a locking surface  25   b . The guide surface  25   a  extends oblique to the inserting direction RID of the retainer  20  at the leading end of the rear resilient locking piece  24 R with respect to the inserting direction RID of the retainer  20 . The locking surface  25   b  is substantially normal to the inserting direction RID of the retainer  20  at a side of the partial locking projection  25  that faces the base end of the rear resilient locking piece  24 R. 
     The full locking projection  26 R is more toward the base end of the rear resilient locking piece  24 R than the partial locking projection  25 , and a partial locking recess  27  is defined between the full locking projection  26 R and the partial locking projection  25  for receiving the fastening projection  15 R of the housing  10 . The full locking projection  26 R has a guide surface  26   a  and a locking surface  26   b . The guide surface  26   a  extends oblique to the inserting direction RID of the retainer  20  and is at a leading side of the full locking projection  26 R with respect to the inserting direction RID of the retainer  20 . The locking surface  26   b  extends substantially normal to the inserting direction RID of the retainer  20  and is at a side of the full locking projection  26 R that faces the base end of the rear resilient locking piece  24 R. A full locking surface  28  is formed more toward the base end than the full locking projection  26 R, and a full locking recess  29  is defined between the full locking projection  26 R and the full locking surface  28  for receiving the fastening projection  15 R of the housing  10 . 
     At the second resilient locking piece  24 R, A projecting distance of the full locking projection  26 R from the central axis of the rear resilient locking piece  24 R is substantially equal to the projecting distance of the partial locking projection  25  from the central axis of the rear resilient locking piece  24 R (see e.g. FIG.  11 ). Thus, the rear end surface of the full locking projection  26 R and the rear end surface of the partial locking projection  25  are substantially flush with each other along a direction parallel with the inserting direction RID of the retainer  20 . Further, the projecting distance of the partial locking projection  25  of the rear resilient locking piece  24 R is substantially equal to that of the partial locking projection  25  of the front resilient locking piece  24 F. 
     The connector is assembled by inserting the retainer  20  into the accommodation space  24 . The resilient locking pieces  24 F,  24 R deform toward each other during this insertion to bring the front ends  24   a  of the resilient locking pieces substantially into contact, as shown in FIG.  3 . As a result, the partial locking projections  25  can move over the corresponding fastening projections  15 F,  15 R. Sufficient insertion of the retainer  20  enables the partial locking projections  25  to pass the fastening projections  15 F,  15 R. Thus, the resilient locking pieces are restored resiliently and the fastening projections  15 F,  15 R engage in the partial locking recesses  27  between the partial locking projections  25  and the full locking projections  26 F,  26 R to hold the retainer  20  at the partial locking position (see FIG.  4 ). 
     Assembly proceeds by inserting the terminal fittings  30  into the respective cavities  12  in the inserting direction ID. As a result, the locks  13  in the cavities  12  engage the locks  31  on the inserted terminal fittings  30 . 
     The retainer  20  then is pushed in the insertion direction RID from the partial locking position to the full locking position. The resilient locking pieces  24 F,  24 R deform toward each other during this pushing process to bring the front ends  24   a  thereof into contact, as shown in FIG.  5 . As a result, the full locking projections  26 F,  26 R move over the corresponding fastening projections  15 F,  15 R. The resilient locking pieces  24 F,  24 R are restored resiliently when the full locking projections  26 F,  26 R pass the fastening projections  15 F,  15 R. Thus, the fastening projections  15 F,  15 R engage the full locking recesses  29  between the full locking projections  26 F,  26 R and the full locking surfaces  28 . As a result, the retainer  20  is held at the full locking position (see FIG.  6 ). In this state, the terminal locks  23  of the retainer  20  engage the second locks  32  of the terminal fittings  30  for locking. The terminal fittings  30  are held securely by the engagement of the terminal locks  23  and the second locks  32  and the engagement of the locks  13  and the first locks  31 . 
     The locked terminal fitting  30  can be withdrawn from the housing  10  by returning the retainer  20  from the full locking position to the partial locking position. This movement is achieved by inserting the leading end of a narrow jig (not shown) into a jig receiving portion  21   a  of the base  21 . The full locking projections  26 F,  26 R are disengaged from the fastening projections  15 F,  15 R by the leverage action of the jig so that the retainer  20  may be moved. The full locking projections  26 F,  26 R move over the corresponding fastening projections  15 F,  15 R in the process of moving the retainer  20  to the partial locking position, and the resilient locking pieces  24 F,  24 R deform toward each other to bring the front ends  24   a  of the resilient locking pieces  24 F,  24 R substantially into contact, as shown in FIG.  5 . The resilient locking pieces  24 F,  24 R are restored resiliently when the full locking projections  26 F,  16 R pass the fastening projections  15 F,  15 R. Thus, the fastening projections  15 F,  15 R engage in the partial locking recesses  27  to hold the retainer  20  at the partial locking position. 
     In this way, the secondary locking of the terminal fittings  30  by the retainer  20  is canceled. A jig (not shown) then may be used to disengage the lock  13  from the first lock  31 , and the terminal fitting  30  may be withdrawn. 
     An excessively large force could be exerted on the retainer  20  as the retainer  20  is moved from the full locking position toward the partial locking position with force. Therefore, there is a danger that such a force could inadvertently deform the resilient locking pieces  24 F,  24 R again and drive the partial locking projections  25  over the fastening projections  15 F,  15 R. Hence, the retainer  20  could come out of the housing  10  without stopping at the partial locking position. 
     However, a preventing means  19  limits displacements of the free ends  24   a  of the resilient locking pieces  24 F,  24 R. More particularly, the free ends  24   a  of the resilient locking pieces  24 F,  24 R are brought substantially into direct contact (see FIG. 7) while the partial locking projections  25  are still engaged with the fastening projections  15 F,  15 R. The restriction on the displacements of the free ends  24   a  makes the resilient locking pieces  24 F,  24 R supported at both the base ends and the free ends  24   a  instead of being supported only at the base ends. This increases apparent resilient forces of the resilient locking pieces  24 F,  24 R and makes it difficult for the resilient locking pieces  24 F,  24 R to undergo resilient deformation. This also prevents the partial locking projections  25  from moving over the fastening projections  15 F,  15 R as the resilient locking pieces  24 F,  24 R are deformed. As a result, the retainer  20  can be held at the partial locking position. 
     Accordingly, deformation of the resilient locking pieces  24 F,  24 R is restricted when the full locking projections  26 F,  26 R move over the fastening projections  15 F,  15 R and the resilient locking pieces  24 F,  24 R are restored resiliently upon the arrival of the retainer  20  at the partial locking position. Thus, the partial locking projections  25  cannot move over the fastening projections  15 F,  15 R. The retainer  20 , therefore, stops securely at the partial locking position, with the fastening projections  15 F,  15 R held between the full locking projections  26 F,  26 R and the partial locking projections  25 . As a result, the retainer  20  cannot be detached from the housing  10 . 
     The resilient locking pieces  24 F,  24 R each are supported at only one end and are inclinably displaceable. The partial locking projections  25  and full locking projections  26 F,  26 R could be made with equal projecting distances. In this situation, the degree of deformation of the resilient locking pieces  24 F,  24 R would be larger when the full locking projections  26 F,  26 R, which are more distant from the free ends  24   a , move over the fastening projections  15 F,  15 R. This would mean that a larger force would be required to move the retainer  20  from the full locking position to the partial locking position. Such a construction would not provide preferable operability for moving the retainer  20  from the partial locking position to the full locking position nor for preventing detachment of the retainer  20  from the housing  10 . 
     However, the projecting distance d of the full locking projection  26 F is less than the projecting distance D of the partial locking projection  25  on the front resilient locking piece  24 F of this embodiment. Therefore, an improved operability can be realized by reducing a force required to move the retainer  20  between the full locking position and the partial locking position without reducing a function of preventing the detachment of the retainer  20  from the housing  10 . 
     The means for restricting displacement of the free ends  24   a  of the resilient locking pieces  24 F,  24 R is realized by bringing the free ends  24   a  of the resilient locking pieces  24 F,  24 R into direct contact. Thus, no preventing means is required on the housing  10 , and the housing  10  has a simpler shape. 
     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 pair of the resilient locking pieces and the pair of the fastening projections are substantially symmetrical in the foregoing embodiment, only one resilient locking piece and only one resilient fastening projection may be provided according to the present invention. In such a case, the displacement of the free end of the resilient locking piece is prevented by bring the free end into contact with the housing. 
     The free ends contact to restrict displacement of the resilient locking pieces in the foregoing embodiment. However, the housing may have a receiving portion to be positioned between the resilient locking pieces for restricting displacement of the free ends. 
     The projecting distance of one full locking projection is less than that of the corresponding partial locking projection in the foregoing embodiment. However, the former projecting distance may be set equal to or larger than the latter projecting distance according to the present invention. 
     Although the projecting distances of the full and partial locking projections are differed on only one of the two resilient locking pieces in the foregoing embodiment, they may be differed in both resilient locking pieces.