Patent Publication Number: US-6905355-B2

Title: Lever-type connector and connector housing therefor

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to a lever-type connector and a housing therefor. 
   2. Description of the Related Art 
   U.S. Pat. No. 5,476,390 discloses a lever-type connector with a female housing. A lever is mounted on the female housing and is formed with a cam groove. The cam groove is engageable with a cam pin on a mating male housing. The housings are positioned initially with the lever at a connection starting position and with the cam pin facing the entrance of the cam groove. The lever then is rotated so that the cam pin moves along the cam groove to pull the housings together. The connector relies on the leverage of the lever to connect the two housings with a small force. 
   The above-described housings may be left partly connected if the rotation of the lever is stopped before the housings are connected properly. An inertial locking mechanism has been studied to prevent the housings from being left partly connected. The inertial locking mechanism temporarily provides a large operation resistance to the lever in the connecting process. The resistance is reduced during the rotation and the lever is rotated to the ending position in a single a stroke. 
   The cam groove could have a steep area to give a high operation resistance to the lever. However, the increase of the maximum operation resistance on the lever could cause an operator to infer incorrectly that the connection is complete. Thus, the operator may stop the connecting operation prematurely, and the connector may be left partly connected. 
   The invention was developed in view of the above problem and an object thereof is to ensure that two housings can be connected properly with high reliability. 
   SUMMARY OF THE INVENTION 
   The invention relates to a lever-type connector with first and second housings that are connectable with each other. A lever is mounted rotatably on the first housing and is formed with a cam means. A mating cam means is provided on the second housing and is engageable with the cam means to display a cam action. The lever is positioned first at a connection starting position so that the cam means engages the mating cam means. An operable portion of the lever is moved away from center axes of the two housings along a connecting direction to an upright position and then is moved towards the center axes of the two housings along a connecting direction and towards an opposite side to bring the lever to a connection ending position for connecting the housings properly. A peak where a connection resistance between the housings and/or an operation resistance on the lever both are at their maximums is set to be reached while the lever is rotated from the upright position towards the connection ending position. Thus, the operation resistance is reduced when the lever is rotated beyond the peak. 
   The lever can be operated beyond the peak position and to the connection ending position at a single stroke by the pushing force exerted on the operable portion of the lever at the peak. The connection resistance between the housings and the operation resistance on the lever are at their maximums at or near the peak. Thus, resistance means for creating an additional inertial force is unnecessary and the maximum value of the operation resistance is lower in absolute value. Therefore, an operator is less likely to stop the connecting operation erroneously due to an increased operation resistance, and the housings can be connected properly with high reliability. 
   The cam means on the lever may be a cam groove, and the mating cam means may be a cam pin. 
   A resilient contact piece of a female terminal fitting mounted in the female housing preferably is deformed resiliently by contact with a tab of a male terminal fitting mounted in the male housing. Thus, the female and male terminal fittings are connected electrically, and the operation resistance on the lever is set to reach its maximum when the tab resiliently deforms the resilient contact piece preferably to a maximum extent. Thus, it is unnecessary to provide additional resistance means to create an inertial force. 
   A resilient seal preferably is provided on at least one of the housings to provide sealing when the housings are connected properly. The operation resistance acting on the lever preferably is set to reach its maximum when the resilient seal member is being deformed. 
   A locking means preferably is provided for locking the lever when the lever is displaced to the connection ending position, and the cam means preferably is provided with a play area for permitting rotation of the lever without advancing the connection of the two housings substantially immediately before or near where the lever reaches the connection ending position. Accordingly, the mating cam means enters the play area immediately before the lever reaches the connection ending position and the connection resistance between the housings preferably is reduced substantially to zero. Thus, the lever can be rotated to the connection ending position and locked at with a single stroke while the force of the lever is maintained. 
   A start locking means preferably is provided for locking the lever at the connection starting position. A start unlocking means also may be provided for disengaging the start locking means, thereby allowing the lever to rotate in the process of connecting the housings. 
   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 side view of male and female housings before connection. 
       FIG. 2  is a front view of the male housing. 
       FIG. 3  is a front view of the female housing. 
       FIG. 4  is a section of a lever. 
       FIG. 5  is a section showing an initial state of the connection. 
       FIG. 6  is a section showing a state where an operation resistance reaches a peak. 
       FIG. 7  is a section showing a properly connected state of the male and female connector housings. 
       FIG. 8  is a graph showing the operation resistance in relation to a lever operation angle. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A lever-type connector according to the invention is illustrated in  FIGS. 1  to  8  and includes a male housing  10 , a female housing  20 , and a lever  40  to be mounted on the female housing  20 . In the following description, connecting sides of the housings  10 ,  20  are referred to as the front side. 
   The male housing  10  is made e.g. of a synthetic resin, and is formed unitarily with an unillustrated device. A substantially rectangular tubular fitting  11  projects forward from the male housing  10 , as shown in  FIGS. 1 and 2 . Two tabs  12  of male terminal fittings project substantially side by side from the back end wall of the tubular fitting  11 . Each tab  12  is a substantially flat plate and has a tapered leading end  12 A. A substantially cylindrical cam pin  13  projects from each of the left and right outer surfaces of the tubular fitting  11  at a position slightly toward the front end in the middle with respect to the height direction HD. An unlocking projection  14  projects above each cam pin  13 . 
   The female housing  20  also is made e.g. of a synthetic resin, and a receptacle  21  projects from the front surface of the female housing  20  for receiving the tubular fitting  11  of the male housing  10 . A tower  22  is formed inside the receptacle  21  and is dimensioned to fit in the tubular fitting  11 , as shown in  FIGS. 3 and 5 . A seal ring  23  is mounted on the rear end of the outer peripheral surface of the tower  22  so that the outer peripheral surface of the seal ring  23  closely contacts the inner peripheral surface of the tubular fitting  11  to close the inside of the connector in a watertight manner when the housings  10 ,  20  are connected properly. Left and right cavities  24  extend from the front end of the tower  22  to the rear end of the female housing  20 . Female terminal fittings  25  are connected with ends of wires W and are inserted into the respective cavities  24  from behind. A rectangular terminal connecting portion  26  is formed at the front end of the female terminal fitting  25 , and a resilient contact piece  27  is folded back and in from the front edge of an upper wall  26 A of the terminal-connecting portion  26 . The resilient contact piece  27  extends substantially straight in a direction obliquely down to the back from the upper wall  26 A. The resilient contact piece  27  then is folded at an intermediate position to extend obliquely up and out. The projecting end of the resilient contact piece  27  is bent forward for contacting the upper wall  26 A. The tab  12  of the corresponding male terminal fitting can be inserted into the terminal connecting portion  26  from the front so that a bottommost portion of the resilient contact piece  27  resiliently contacts the tab  12  to electrically connect the male and female terminal fittings  12 ,  25 . 
   The lever  40  is made e.g. of a synthetic resin and has left and right arms  41  joined by a coupling  42  to define a substantially U-shape. The arms  41  are mounted to the female housing  20  to hold the opposite left and right sides of the receptacle  21 . Leading ends of the arms  41  have shaft-bearing recesses  43  that are supported rotatably on shafts  28  that project from the left and right outer surfaces of the receptacle  21 . A cam groove  44  is formed in the inner surface of each arm  41  and is engageable with the corresponding cam pin  13  of the male connector housing  10  (see FIG.  4 ). Each cam groove  44  has an entrance  44 A, a terminus  44 B and an arcuate play area  44 B at an intermediate position near the terminus  44 B. A section of the cam groove  44  from the entrance  44 A to the arcuate play area  44 C gradually approaches the shaft bearing recess  43 . However, the distance from the cam groove  44  to the shaft bearing recess  43  remains substantially constant through the arcuate play area  44 C. The entrances  44 A of the cam grooves  44  face forward on the female housing  20  (see  FIG. 5 ) at a connection starting position CSP. The housings  10 ,  20  are positioned so that the cam pins  13  enter the cam grooves  44 . The lever  40  then is rotated in a connection rotation direction CRD (clockwise direction of  FIG. 5 ) and the cam pins  13  are displaced along the cam grooves  44  to assist the connection of the housings  10 ,  20 . The lever  40  is rotated without advancing the connection of the two housings  10 ,  20  when the cam pins  13  enter the play areas  44 C. The two housings  10 ,  20  are connected properly when the cam pins  13  reach connection ending positions CED located at the termini  44 B of the cam grooves  44 , as shown in FIG.  7 . 
   A locking piece  46  is formed on each arm  41  near the coupling  42  and is resiliently deformable substantially along a thickness direction TD of each arm  41  (FIG.  3 ). The locking pieces  46  substantially engage the front end of the receptacle  21  when the lever  40  is at the connection starting position CSP (see FIGS.  3  and  5 ). An operable portion  48  is provided in the middle of the front surface of the coupling  42  for receiving fingers to rotate the lever  40 . The arms  41  extend along the side surfaces of the housing  20  when the lever  40  is in the connection starting position CSP and the operable member  48  contacts a portion of the housing  20 . The unlocking projections  14  of the male housing  10  resiliently deform the locking pieces  46  out to disengage the locking pieces  46  from the receptacle  21  during connection of the housings  10 ,  20 , thereby allowing the lever  40  to rotate. 
   A resiliently deformable lock arm  47  is cantilevered from a substantially a middle part of the coupling  42 . On the other hand, a lock projection  29  extends back from the middle of the upper surface of the female housing  20 . The lock arm  47  engages the lock projection  29  when the lever  40  reaches the connection ending position CED. Thus, the lever  40  is held so as not to rotate and the housings  10 ,  20  are held connected with each other. The arms  41  are reclined along the side surfaces of the housing  20  when the lever  40  is in the connection ending position CEP, but extend in a direction substantially opposite the direction that exists in the connection starting position CSP. Thus, the operable member  48  contacts a substantially opposite portion of the housing  20 . 
   The lever  40  initially is held at the connection starting position CSP with respect to the female housing  20 . The tubular fitting  11  of the male housing  10  then is fit lightly into the receptacle  21  of the female housing  20  as shown in FIG.  5 . Thus, the cam pins  13  enter the entrances  44 A of the cam grooves  44 . In this process, the unlocking projections  14  contact the locking pieces  46  of the lever  40  and resiliently deform the locking pieces  46  out in a disengagement direction sufficiently to disengage the locking pieces  46  from the female housing  20 . In this way, the lever  40  at the connection starting position CSP is released from its rotation-movement-prevented state. 
   Fingers then are placed on the operable portion  48  of the lever  40  to move the operable portion  48  obliquely up and away from the housings  10 ,  20 . Thus, the operable portion  48  is moved away from center axes of the two housings  10 ,  20  along a connecting direction CD (transverse direction of FIG.  5 ), thereby rotating the lever  40  in the connection rotation direction CRD (clockwise in FIG.  5 ). As a result, the housings  10 ,  20  are pulled toward each other along the connection direction CD and gradually are connected with each other by a cam action between the cam pins  13  and the cam grooves  44 . The tapered leading ends  12 A of the tabs  12  enter the terminal connecting portions  26  of the female terminal fittings  25  and contact the resilient contact pieces  27 . The tapered leading ends  12 A of the tabs  12  gradually push the resilient contact pieces  27  up and out as the two housings  10 ,  20  are connected further, thereby resiliently deforming the resilient contact pieces  27 . The operable portion  48  eventually reaches an upright position UP (shown in phantom in  FIG. 5 ) where an imaginary line IL ( FIG. 4 ) passing through the operable portion  48  and the shaft bearing recesses  43  is substantially perpendicular to the connecting direction CD and where the operable portion  48  is most distanced from the center axes of the two housings  10 ,  20  along the connecting direction CD (transverse direction of FIG.  5 ). The lever  40  then is rotated further in the connection rotation direction CRD by pushing the operable portion  48  down towards the opposite side. 
   In this connecting process, an operation resistance resulting from a connection resistance between the two housings  10 ,  20  acts on the lever  40  as shown in FIG.  8 . This operation resistance gradually increases as the resilient contact pieces  27  are deformed to a larger extent after the tapered leading ends  12 A of the tabs  12  contact the resilient contact pieces  27  (P 1 ) as shown in FIG.  8 . The resilient contact pieces  27  pass the tapered leading ends  12 A of the tabs  12  and deform to a maximum extent when the lever  40  is rotated beyond the upright position UP (P 2 ), as shown in FIG.  6 . At this time, a peak (P 3 ) is reached where the connection resistance acting between the two housings  10 ,  20  (e.g. also due to the compression of the seal ring  23  between the two housings  10 ,  20 ) and the operation resistance acting on the lever  40  is at its maximum. 
   At this point, a force exceeding the operation resistance at the peak (P 3 ) is exerted on the operable portion  48  to rotate the lever  40  further. The connection resistance acting between the two housings  10 ,  20  then is reduced because the degree of deformation of the resilient contact pieces  27  does not change from this time on. Accordingly, the operation resistance on the lever  40  is reduced. Therefore, the lever  40  is rotated in a single stroke by the pushing force exerted at the peak (P 3 ). As a result, the two housings  10 ,  20  are connected to a proper depth in a single stroke (P 4 ). 
   The cam pins  13  enter the play areas  44 C of the cam grooves  44  when the lever  40  is rotated from this state (P 4 ). Thus, the lever  40  is idly rotatable and the connection resistance between the housings  10 ,  20  becomes zero. The operable portion  48  of the lever  40  is rotated with an ongoing force due to the sudden reduction in the operation resistance on the lever  40 . The leading end of the lock arm  47  then contacts the lock projection  29  (P 5 ) and deforms sufficiently to move onto the upper surface of the lock projection  29 . The lock arm  47  then moves over the lock projection  29  and is restored resiliently to engage the lock projection  29 . In this way, the lever  40  is locked at the connection ending position CED and the two housings  10 ,  20  are locked in their properly connected state. 
   As described above, the lever  40  is pushed to the connection ending position CED in a single stroke by the pushing force exerted on the operable portion  48  at the peak (P 3 ) of the operation resistance. The connection resistance acting between the housings  10 ,  20  and the operation resistance acting on the lever  40  are set to be at their maximums at the peak (P 3 ). Thus, it is not necessary to provide separate resistance means for creating an inertial force and accordingly the maximum value of the operation resistance can be lower. Therefore, an operator is less likely to stop the connecting operation erroneously due to an increase in the operation resistance, and the two housings  10 ,  20  can be connected properly with high reliability. 
   The peak (P 3 ) is reached when the tabs  12  resiliently deform the resilient contact pieces  27  to the maximum extent. Thus, it is not necessary to provide additional resistance means for creating an inertial force. 
   The cam pins  13  enter the play areas  44 C of the cam grooves  44  to reduce the connection resistance between the two housings  10 ,  20  to zero immediately before the lever  40  reaches the connection ending position CED to be locked. Thus, the lever  40  can be rotated to the connection ending position CED ( FIG. 7 ) and locked in a single stroke while the ongoing force of the lever  40  is maintained. 
   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 lever is mounted on the female housing in the foregoing embodiment, it may be mounted on the male housing. 
   The means for locking the lever at the connection ending position CED may be provided between the lever and the mating housing to be connected with the housing on which the lever is directly mounted. 
   Although the movable member is described to be a rotatable lever in the above-described embodiment, it should be understood that the invention is applicable to any other movable member such as a substantially linearly or arcuately movable member having a suitable cam means engageable with mating cam means provided on the corresponding housing.