Abstract:
A lock arm ( 12 ) on a female housing ( 1 ) is deformed at an intermediate stage of connecting the female housing ( 1 ) with a mating male housing ( 20 ). A lock ( 13 ) at the leading end of the lock arm ( 12 ) contacts an edge ( 23 D) of an engaging portion ( 23 ) on the male housing ( 20 ) and then parts therefrom by canceling a rubbing state. The lock arm ( 12 ) then restores resiliently and the lock ( 13 ) engages the engaging portion ( 23 ) to lock the housings ( 1, 20 ) in a properly connected state. At least one of the lock ( 13 ) and the edge ( 23 D) of the engaging portion ( 23 ) that rub against each other immediately before the proper connection of the two housings ( 1, 20 ) has a resistance alleviating portion ( 13 C) with an apex locally projecting toward the other rubbed part.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     2. Field of the Invention  
         [0002]     The invention relates to a connector.  
         [0003]     2. Description of the Related Art  
         [0004]     U.S. Pat. No. 5,336,101 discloses a connector assembly with male and female housings that can be connected together. A lock arm is provided on an upper surface of the female housing and a lock is formed on the leading end of the lock arm. The lock arm can pivot about the base end so that the lock at the leading end of the lock arm displaces. An engaging projection is provided on the upper surface of the male housing. The lock moves onto the engaging projection during the connection of the male and female housings. The lock then contacts the rear edge of engaging projection and parts from the rear edge that have been rubbed against. The lock arm then returns resiliently while following a pivoting path. In this way, the lock engages the engaging projection to lock the male and female housings in their connected state.  
         [0005]     The rear edge of the leading end of the above-described lock and the rear edge of the engaging projection are in line contact with each other along the width direction when they part from each other in the connecting process. Thus, the rear edge of the leading end of the above-described lock and the rear edge of the engaging projection cannot part smoothly from each other due to contact resistance therebetween. Accordingly, a connection feeling upon connecting or separating the two housings deteriorates.  
         [0006]     The invention was developed in view of the above problem and an object thereof is to improve connection feeling and separation feeling upon connecting and separating two connectors.  
       SUMMARY OF THE INVENTION  
       [0007]     The invention relates to a connector with first and second housings that are connectable with each other. A resiliently deformable lock arm is provided on the first housing and includes a lock. An engaging portion is provided on the second housing. The lock arm deforms resiliently at least at an intermediate stage of a connecting operation of the two housings. The lock contacts an edge of the engaging portion immediately before proper connection of the two housings. As a result, the lock arm is restored resiliently so that the lock engages the engaging portion to lock the two housings in a properly locked state. At least one of the lock and the edge of the engaging portion that rub together immediately before the proper connection of the housings has a resistance alleviating portion with an apex that projects locally towards the mating rubbed part.  
         [0008]     The lock preferably is at the leading end of the lock arm.  
         [0009]     The lock preferably parts from the edge by canceling a rubbed state against the edge at or after the proper connection of the two housings. Thus the lock arm is restored resiliently.  
         [0010]     The resistance alleviating portion achieves point contact when the lock contacts the edge of the engaging portion in the process of connecting the two housings. As a result, contact resistance is reduced and the lock arm hits the mating housing with a force that makes a loud hitting or clicking sound with an audible and tactile indication of connection. Therefore, connection feeling is improved. Similarly, the lock and the edge of the engaging portion are in point contact when the lock contacts the edge during the separation the two housings. Thus, separation feeling is improved and the separating operation is completed without a dragging feeling.  
         [0011]     The lock arm preferably is cantilevered forward, and the lock is at or near the leading end of the lock arm. The engaging portion preferably is a projection on an outer surface of the other housing.  
         [0012]     The resistance alleviating portion preferably is a cone or a polygonal pyramid at a part of the lock to be rubbed against the rear edge of the engaging portion and has an apex oriented substantially towards an engaging side.  
         [0013]     An unlocking lever preferably is provided separately from the lock arm. The unlocking lever does not deform during connection of the two housings. However, an operable portion can be operated to deform the unlocking lever, and deformation of the unlocking lever deforms the lock arm in an unlocking direction so that the housings can be separated.  
         [0014]     Protection walls preferably are formed at the sides of the engaging portion and preferably extend in forward and backward directions over substantially the entire length.  
         [0015]     At least one guiding wall may slide in contact with surfaces of the protection walls for guiding the connection.  
         [0016]     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  
       [0017]      FIG. 1  is a longitudinal section showing a state before male and female connector housings are connected.  
         [0018]      FIG. 2  is a plan view showing the state of  FIG. 1 .  
         [0019]      FIG. 3  is a longitudinal section showing a state attained by completing the connection of the male and female connector housings.  
         [0020]      FIG. 4  is a plan view showing the state of  FIG. 3 .  
         [0021]      FIG. 5  is a longitudinal section showing an intermediate state of a connecting operation of the male and female connector housings.  
         [0022]      FIG. 6  is a perspective view partly in section showing a lock portion. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0023]     A connector assembly according to the invention is illustrated in FIGS.  1  to  6 . The connector assembly has male and female connectors that are connectable with each other substantially along a connecting direction CD. In the following description, reference is made to  FIG. 1  concerning the vertical direction. The vertical direction in  FIG. 2  is referred to as the width direction WD, the transverse direction in  FIG. 1  is referred to as forward and backward directions FBD, and ends to be connected are referred to as the front.  
         [0024]     The male connector includes a male housing  20  made e.g. of a synthetic resin, and male terminals  30  are inserted into the male housing  20  from behind. The male housing  20  has a wide block-shaped main portion  21  and a receptacle  22  projects unitarily from the front surface of the main portion  21 . The male housing  20  has locks  25  that lock the male terminals  30  in positions so that tabs of the male terminals  30  project from the back surface of the receptacle  22 . A retainer  26  is thrust under the leading end of the locks  25  to retain the male terminals  30 . The retainer  26  also serves as a front-stop for the male terminals  30 .  
         [0025]     The female connector has a female housing  1  made e.g. of a synthetic resin. The female housing  1  has a wide block-shaped terminal accommodating portion  2  and a tubular portion  3  at least partly covers the terminal accommodating portion  2 . The receptacle  22  can fit between the tubular portion  3  and the terminal accommodating portion  2 . Cavities  4  extend in substantially forward and backward directions in the terminal accommodating portion  2 , and female terminals  6  are insertable into the cavities  4  from behind and along an inserting direction ID. A lock  5  is formed at the bottom surface of each cavity  4 .  
         [0026]     Each female terminal  6  is crimped, bent or folded into connection with a wire W and with a waterproof rubber plug  7  at an end of the wire W. Additionally, each female terminal  6  is configured to be connected with the male terminal  30 . The female terminals  6  can be inserted into the cavities  4  from behind. As a result, the female terminal  6  contacts the lock  5  and deforms the lock  5  out in a direction intersecting the inserting direction ID. The lock  5  is restored resiliently to lock the female terminal  6  when the female terminal  6  reaches a proper position. A retainer  9  is mountable from the front of the terminal accommodating portion  2  to prevent outward deformation of the locks for doubly locking the female terminals  6 . The retainer  9  also retains a seal ring  8  fit at or near the base side of the terminal accommodating portion  2  to provide sealing between the two housings  1 ,  20 .  
         [0027]     An engaging portion  23  is formed on the upper surface of the receptacle  22  of the male housing  20  in a substantially middle position with respect to forward and backward directions FBD and a width direction WD that is substantially normal to the forward and backward directions FBD. A slanted or rounded guiding surface  23 B is formed at the front of the engaging portion  23 , and an upright engaging surface  23 A is formed at the rear of the engaging portion  23 . The engaging surface  23 A is substantially normal to the connecting direction CD. Protection walls  24  are formed on the upper surface of the receptacle  22  and extend in substantially forward and backward directions FBD at opposite widthwise sides of the engaging portion  23 .  
         [0028]     An arch  10  bulges out at the front side of the upper surface of the tubular portion  3  and is hollow in forward and backward directions FBD. Guiding walls  11  are formed on the substantially opposite side surfaces of the arch  10 . The guiding walls  11  guide connecting movements of the two housings  1 ,  20  by the sliding contact of the outer surfaces of the protection walls  24  and the inner surfaces of the guiding walls  11 . As shown in  FIG. 2 , preventing walls  18  bulge out from the rear sides of the guiding walls  11  and then extend straight back.  
         [0029]     A lock arm  12  is formed in an area of the upper surface of the female housing  1  at least partly surrounded by the arch  10  and the preventing walls  18 . The lock arm  12  extends substantially in forward and backward directions FBD and substantially parallel to the connecting direction CD. A lock  13  is formed at the front end of the lock arm  12  and two substantially parallel arms  14  extend back from the lock  14 . The arms  14  are spaced apart by a distance slightly greater than the width of the engaging portion  23  of the male housing  20 . Bases  15  extend unitarily between rear ends of the arms  14  and a part of the upper surface of the female housing  1  behind the tubular portion  3 . The lock arm  12  cantilevers forward from the bases and can undergo a resilient pivoting movement with the bases  15  as supports. Thus, front portions of the lock arm  12 , including the lock  13 , can deflect resiliently up and down in a direction intersecting the connecting direction CD.  
         [0030]     An unlocking lever  17  is provided separately from the lock arm  12 , as shown in  FIG. 2 , and is configured for unlocking the lock arm  12 . The unlocking lever  17  extends substantially in forward and backward directions FBD between the arms  14  of the lock arm  12 . Auxiliary levers  19  are provided at the opposite widthwise sides of the unlocking lever  17  and between the preventing walls  18 . The auxiliary levers  19  extend substantially parallel with the unlocking lever  17 , and rear ends of the auxiliary levers  19  and the unlocking lever  17  are connected by an operable portion  17 A. Intermediate parts of the unlocking lever  17  and the auxiliary levers  19  are coupled to the upper surface of the terminal accommodating portion  2  on substantially the same line. Thus, a pressing force on the operable portion  17 A will cause the unlocking lever  17  and the auxiliary levers  19  to make inclining movements together with the respective coupled positions as fulcrums.  
         [0031]     Unlocking pieces  17 B are formed at the front end of the unlocking lever  17  and project laterally out from the lower third of the unlocking lever  17 . On the other hand, an unlock interacting piece  14 A projects laterally in from the upper third of each arm  14 . The lower surfaces of the unlock interacting piece  14 A oppose the upper surfaces of the corresponding unlocking piece  17 B with a small clearance therebetween. The lock arm  12  deforms resiliently during connection of the two housings  1 ,  20  and engages the engaging portion  23  without inclining the unlocking lever  17 . However, the operable portion  17 A can be pressed to incline the unlocking lever  17 . Accordingly, the unlocking pieces  17 B contact the unlock interacting pieces  14 A and the lock arm  12  inclines in unlocking direction together with the unlocking lever  17  so that the two housings  1 ,  20  can be separated.  
         [0032]     The lock  13  bridges the leading ends of the arms  14 , and a locking surface  13 A is defined at the rear of the lock  13 . As shown in  FIG. 6 , the locking surface  13 A has a vertical area  13 B extending substantially normal to the connecting direction CD and a resistance alleviating portion  13 C for alleviating resistance to the rear end of the upper surface of the engaging portion  23 . The resistance alleviating portion  13 C is substantially a section of a cone and has an apex substantially in the middle of the upper edge of the locking surface  13 A. The bottom of the resistance alleviating portion  13 C is close to the bottom edge of the locking surface  13 A and bulges out horizontally to define a separating point P substantially at the widthwise center of the bottom edge of the locking surface  13 A. The bulging amount of the resistance alleviating portion  13 C is reduced gradually and symmetrically from the separating point P toward the opposite sides. Accordingly, the lock  13  can move onto the engaging portion  23  immediately before the two housings  1 ,  20  are connected properly. Additionally, the upper surface of the engaging portion  23  contacts the lock  13  only at the separating point P in a moment when the lock  13  passes the upper surface of the engaging portion  23 .  
         [0033]     The connector is assembled by mounting the seal ring  8  on the outer surface of the terminal accommodating portion  2 . The female terminals  6  then are inserted into the respective cavities  4  of the female housing  1  from behind and along the inserting direction ID. Each female terminal  6  deforms the respective lock  5  during the insertion. However, the lock  5  restores resiliently when the female terminal  6  reaches the proper position to lock the female terminal  6 . The retainer  9  then is fit from the front of the terminal accommodating portion  2  and into the space adjacent the locks  5  to prevent downward movement of the locks  5  and to lock the female terminals  6  redundantly. The retainer  9  also holds the seal ring  8  in position on the outer surface of the terminal accommodating portion  2 . Similar operations are performed to assemble the male terminals  30  into the male housing  20 .  
         [0034]     The receptacle  22  of the male housing  20  then is fit in the connecting direction CD between the terminal accommodating portion  2  and the tubular portion  3  of the female housing  1 . In this fitting process, the front-bottom of the lock  13  contacts the guiding surface  23 B. The lock arm  12  inclines independently of the unlocking lever  17  and in a direction intersecting the connecting direction CD as the connecting operation progresses. Thus, the lock  13  slides on and along the guiding surface  23 B and then moves onto the upper surface  23 C of the engaging portion  23 . The locking surface  13 A is oblique to the vertical surface and to the connecting direction CD. As a result, the separating point P advances while being held substantially in point contact with the upper surface  23 C. The locking surface  13 A contacts the rear edge  23 D of the engaging portion  23  only at the separating point P, and therefore can part more smoothly the rear edge  23 D of the engaging portion  23  because of smaller resistance as compared to the line contact as in the prior art. The lock  13  then is freed from the contact state with the engaging portion  23  and restores resiliently to follow a pivoting path towards the front-lower side of the rear edge  23 D. Thus, the locking surface  13 A and the engaging surface  23 A engage to lock the two housings  1 ,  20  in the connected state.  
         [0035]     The operable portion  17 C of the unlocking lever  17  is pressed down towards the housing  1  to separate the two housings  1 ,  20 . Thus, the unlocking pieces  17 B contact the unlock interacting pieces  14 A, and the lock  13  at the leading end of the lock arm  12  is lifted outwardly as the leading end of the unlocking lever  17  moves away from the housing  1 . The resistance alleviating portion  13 C of the lock  13  contacts the rear edge  23 D of the engaging portion  23  as the two housings  1 ,  20  are pulled apart from each other. At this time, the resistance alleviating portion  13 C and the rear edge  23 D are substantially in point contact. Hence, the two housings  1 ,  20  can be pulled part without any dragging feeling and the contact resistance is held down.  
         [0036]     As described above, the lock  13  and the engaging portion  23  are substantially in point contact with each other due to the resistance alleviating portion  13 C on the locking surface  13 A. By alleviating the contact resistance, it becomes possible to improve connection feeling and separation feeling.  
         [0037]     The invention is not limited to the above described and illustrated embodiment. For example, the following embodiments also are 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.  
         [0038]     Although the resistance alleviating portion assumes the shape of a section of a cone in the foregoing embodiment, it may assume another shape provided that the lock and the engaging portion can be held substantially in point contact. For example, the resistance alleviating portion may assume the shape of a triangular or polygonal pyramid or have a substantially elliptic or pointed protruding shape.  
         [0039]     Although the lock is formed with the resistance alleviating portion in the first embodiment, the engaging portion may be formed therewith provided that the lock and the engaging portion can be held substantially in point contact.  
         [0040]     Although the lock arm is cantilevered in the foregoing embodiment, it may be supported at both ends or have a substantially bridge-like shape. The lock arm may assume any shape provided that the lock and the engaging portion can be held substantially in point contact at their touching portions immediately before the lock arm starts being resiliently deformed.