Abstract:
A connector includes a housing having a plurality of cavities, a plurality of resiliently deformable locking members, and a plurality of terminals. Each terminal is inserted in the respective cavity and has (a) a partially inserted position in which the terminal bears on the respective locking member to deform the locking member so that the locking member is elevated with respect to a peripheral surface of the housing, and (b) a fully inserted position in which the locking member snap-fits to the terminal thereby locking the terminal in the cavity. The connector further includes a bus bar holder having a sleeve and a plurality of bus bar tab pieces which are accommodated in the sleeve. The sleeve is push-fitted over the peripheral surface of the housing via a partially installed position, at which the tab pieces do not contact said terminals, to a fully installed position, at which the tab pieces contact said terminals. In this way, in the fully installed position, the bus bar holder is installed to the housing with the terminals electrically connected to each other. In addition, each locking member is adapted so that when the terminal is in the partially inserted position with the respective locking member elevated with respect to the peripheral surface of the housing and an attempt is made to push-fit the sleeve to the partially installed position, the sleeve bears on the locking member to prevent the sleeve arriving at the partially installed position. The connector also comprises a detent for detaining said bus bar holder at said partially installed position. An assembling jig is provided which, if the connector is not properly assembled at the partially installed position, will not accept the connector.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates to a connector, particularly a connector for use in the wiring of a vehicle such as an automobile, and a jig for assembling the connector. 
     2. Description of Related Art 
     A connector which is capable of detecting the incomplete insertion of a terminal is disclosed in Japanese Patent Application Laid-Open No. 9-106847. In the connector, cavities are formed in a housing. A lance for preventing removal of a terminal is formed in each cavity such that the locking lance confronts an outer surface of the housing, and a retainer is installed on the outer surface of the housing. In the case where every terminal has been inserted into the normal position of each cavity, the locking lances are flush with the outer surface of the housing. In this case, the retainer can be installed on the housing without the retainer interfering with the locking lances. On the other hand, in the case where any of the terminals has not been inserted into the normal position of each cavity, the terminal bears on the locking lance and the locking lance is projected outwardly from the outer surface of the housing. In this case, when the retainer is installed on the housing it collides with the locking lance. Thus, the installation of the retainer on the housing is suspended. In this manner, it is possible to detect whether the terminal has been properly inserted by whether the retainer can be installed on the housing. 
     However, there remains a problem when installation of the retainer is performed at the same time that a bus bar is connected to the terminals. During installation of the bus bar, the bus bar engages the terminals. As a result, frictional resistance is generated, and the operator performing the installation may mistakenly believe that installation resistance has been caused not by the collision between the retainer and the locking lance but by the friction between the bus bar and the terminals. In this case the operator may continue with the installation of the bus bar and the retainer on the housing, and consequently the locking lance may be broken. Alternatively, the operator may mistakenly believe that installation resistance has been generated not by friction between the bus bar and the terminal fitting but by the collision between the retainer and the locking lance and may unnecessarily check the insertion state of the terminal. 
     SUMMARY OF THE INVENTION 
     Therefore, it is an object of the present invention to reliably detect the incomplete insertion of a terminal. 
     According to a first aspect of the present invention there is provided a connector including a housing having a plurality of cavities, a plurality of resiliently deformable locking members, and a plurality of terminals. Each terminal is inserted in the respective cavity and has (a) a partially inserted position in which the terminal bears on the respective locking member to deform the locking member so that the locking member is raised with respect to a peripheral surface of the housing and (b) a fully inserted position in which the locking member snap-fits to the terminal thereby locking the terminal in the cavity. The connector further includes a bus bar holder having a sleeve and a plurality of bus bar tab pieces which are accommodated in the sleeve. The sleeve is push-fitted over the peripheral surface of the housing via a partially installed position, at which the tab pieces do not contact the terminals, to a fully installed position, at which the tab pieces contact the terminals. In this way, in the fully installed position, the bus bar holder is installed to the housing with the terminals electrically connected to each other. 
     In addition, each locking member is adapted so that when a terminal is in its partially inserted position with the respective locking member elevated from the peripheral surface of the housing and an attempt is made to push-fit the sleeve to the partially installed position, the sleeve bears on the locking member to prevent the sleeve from arriving at the partially installed position. The connector also includes a detent that detains the bus bar holder at the partially installed position. 
     During installation of the bus bar holder on the housing up to and including when the holder reaches the partially installed position, the bus bar holder is not subjected to any resistance that may be generated by the contact between the bus bar tab pieces and the terminals. However, after the bus bar holder passes the partially installed position, the tab pieces start to contact the terminals. Accordingly, it is possible to discriminate between the installation resistance on the bus bar holder due to the collision between a locking member and the sleeve, and the installation resistance that is generated due to collision or friction between the terminals and the tab pieces, because the former installation resistance would be felt before the bus bar holder reached the partially installed position. In this manner, it is possible reliably to detect the insertion state of the terminals. 
     In a second aspect of the present invention there is provided an assembly jig for setting thereon the connector of the first aspect of the invention and for assembling the connector by push-fitting the sleeve of the connector from the partially installed position to the fully installed position. The jig is sized so that when the sleeve of the connector is prevented from arriving at the partially installed position the connector is prevented from being set on the jig. On the other hand, when the sleeve of the connector is at the partially installed position the connector, is settable on the jig. 
     If the bus bar holder is prevented from arriving at the partially installed position by a collision between the sleeve and a locking member, which is in turn caused by the corresponding terminal having not been fully inserted, it is impossible to set the connector on the assembly jig. This is so even if the operator has not previously detected the incomplete insertion of the terminal. In this manner, it may be reliably detected that one or more of the terminals is in an incomplete insertion state. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     An embodiment of the invention will now be described by way of non-limitative example with reference to the accompanying drawings, in which: 
     FIG. 1 is a perspective view of the housing, sealing member and seal holder of a connector embodying the invention; 
     FIG. 2 is a partly cut-away perspective view of a bus bar unit of the connector of FIG. 1; 
     FIG. 3 is a perspective view of a cap for the connector shown in FIG. 1; 
     FIG. 4 is a partly cut-away plan view of the connector in an assembled state; 
     FIG. 5 is a partly cut-away plan view of the connector in which a bus bar unit is positioned at a temporary locking position; 
     FIG. 6 is a sectional view on line  6 — 6  of FIG. 4 including terminals in the connector cavities (in broken lines), a lower bus bar unit fully installed, and an upper bus bar unit bearing on a locking lance; 
     FIG. 7 is the same sectional view as FIG. 6 with bus bar units in partially installed positions and the connector set on an assembly jig; 
     FIG. 8 is the same sectional view as FIG. 7 but with both bus bar units moved to fully installed positions by the assembly jig; 
     FIG. 9 is the same section view as FIG. 6, but with the upper bus bar unit prevented from arriving at its partially inserted position; and 
     FIG. 10 is the same section view as FIG. 6 but with both bus bar units fully installed. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     A connector embodying the present invention is shown in FIGS. 1 to  10 . The connector electrically connects a plurality of terminals  20  in a predetermined connection pattern with a bus bar  55  and has a housing  10 , a plurality of the terminals  20 , a sealing member  30 , a seal holder  40 , two bus bar units  50 , and a cap  60 . 
     The housing  10  is made of a synthetic resinous material. As shown in FIG. 1, the housing  10  has cavities  11  arranged in upper and lower rows and extending through the housing  10  in a front-to-rear direction. In each of the upper and lower rows, the cavities  11  may be arranged widthwise at regular intervals. The front half region of the upper-row cavities  11  and the lower-row cavities  11  are open at the upper and lower surfaces of the housing  10 , respectively. In each open portion, locking members, such as locking lances  12 , project forward in a cantilever manner. Between the upper and lower rows of the cavities  11  there is formed a wide recess  13  for allowing the peripheral walls of the bus bar units  50  to penetrate. An upper surface wall and a lower surface wall of the recess  13  are partly cut away to allow communication with the cavities  11 . 
     The locking lances  12  retain and prevent the removal of the terminals  20  inserted into the cavity  11 . In cooperation with a cylindrical portion  53  of the bus bar unit  50 , it is also used for detecting the degree of insertion of the terminal  20 . As shown in FIG. 6, each locking lance  12  can be outwardly elastically displaced relative to an outer surface of the housing  10 . Before each terminal  20  is inserted into each cavity  11  or when the terminals  20  are fully inserted therein, the locking lances  12  are undeformed, and an outer surface of the locking lance is flush with the outer surface of the housing  10 . In this state, a removal prevention projection formed at a front end of the locking lance  12  is engaged in a locking hole  24  of the terminal  20  (see lower bus bar unit of FIG.  6 ), thus preventing removal of the terminals  20 . However, when any terminal  20  is not fully inserted, the removal prevention projection interferes with the outer surface of a mating portion  21  of the terminals  20  that are not fully inserted. As a result, the corresponding locking lances  12  are elastically displaced outward such that the outer surface is located outwardly from the outer surface of the housing  10  (see upper bus bar unit of FIG.  6 ). Therefore, when each bus bar unit  50  is installed on the housing  10 , the cylindrical portion  53  of the bus bar unit  50  collides with the front end of the locking lances  12 . This prevents the bus bar from being completely installed. 
     Each terminal  20  is made of a metal plate material punched into a predetermined configuration. As shown in FIG.  1  and FIG. 6, the front half part of each terminal  20  may be formed as a square pillar-shaped mating portion  21  that is open forward and rearward. The rear half of the terminal  20  is formed as an electric wire connection portion  22  that may be crimped to the core of an electric wire  25 . 
     As shown in FIGS. 6-10, a resilient contact piece  23  that contacts a connection piece  57  of the bus bar  55 , described in detail below, is formed inside the mating portion  21 . The locking hole  24  with which the locking lance  12  of the housing  10  engages is formed on a peripheral wall of the mating portion  21 . Each terminal  20  is inserted into a respective cavity  11  of the housing  10  by passing it through the seal member  30  and the seal holder  40  installed on the housing  10  from the rear of the housing  10 . Immediately before the terminal  20  reaches its fully inserted position, the locking lance  12  interferes with the peripheral surface of the mating portion  21 . Therefore, the locking lance  12  flexes elastically outward from the housing  10 . When the terminal  20  reaches the fully inserted position, the locking lance  12  is elastically restored to its original state and is engaged in the locking hole  24 , thus preventing the terminal  20  from being removed from the cavity  11 . The orientation of the terminals  20  in the upper row of cavities  11  is preferably reversed relative to that of the terminals in the lower cavity row. 
     The sealing member  30  is made of rubber, oval-shaped, and thick. As shown in FIG. 1, the sealing member  30  is installed on the housing  10  and is sandwiched between the rear end surface of the housing  10  and the front end surface of the seal holder  40 . As shown in FIG. 4, a plurality of sealing holes  31  that are open at the front and rear surfaces of the sealing member  30  are formed coincident with the cavities  11  of the housing  10 . Each sealing hole  31  may be circular, for example. A lip portion  31 A of corrugated shape has, for example, three convexities which are circumferentially formed on the inner peripheral surface of each sealing hole  31  as shown in FIGS. 4-5. The inner diameter of the lip portion  34  is smaller than the outer diameter of the coating of the wire  25 . When a wire  25  is in a sealing hole  31 , as shown in FIG. 6, the lip portion contacts the peripheral surface of the wire  25  elastically, thus sealing around the wire  25 . 
     The peripheral edge of the sealing member  30  is formed as a corrugated sealing edge. The lip portion  34  also has, for example, three convexities approximately semi-circular in section extending circumferentially around the sealing member  30 . The lip portion  34  contacts the inner peripheral surface of the cap  60  elastically, thus sealing between the sealing member  30  and the cap  60 . 
     The seal holder  40  is made of a relatively rigid synthetic resin material. Similarly to the sealing member  30 , the seal holder  40  may be oval-shaped. The lip portion  34  formed on the periphery of the sealing member  30  is slightly larger than the periphery of the seal holder  40 . A plurality of terminal insertion openings  41  shown in FIGS. 4-6 extend between the front and rear end surfaces of the seal holder  40  in correspondence to the cavities  11  and the sealing holes  31 . Each terminal  20  is inserted into a respective cavity  11  through a respective terminal insertion opening  41 . 
     Two locking projections  44  are formed at each end of upper and lower flat peripheral surfaces of the seal holder  40 . The locking projections  44  engage the cap  60 , thus hindering the cap  60  from being easily removed from the housing  10 , the sealing member  30  and the seal holder  40 . An index projection  45  is formed in each circular arc-shaped region located at right and left ends of the peripheral surface of the seal holder  40 . Each of a pair of the index projections  45  may be formed such that the inward side thereof is on a level higher than that of the outward side thereof. The index projections  45  serve as indexes for checking the upper and lower sides of the housing  10  when the terminals  20  are inserted into the cavities  11 . 
     As shown in FIG. 2, the bus bar unit  50  is composed of a holding member  51  made of a relatively rigid synthetic resin material and a metal bus bar  55  integrated with the holding member  51  by insert molding. The holding member  51  has a wide sheet-shaped holding portion  52  and a flat cylindrical portion  53  projecting rearward (direction toward the housing  10 ) from the sheet-shaped holding portion  52 . The bus bar  55  includes a plurality of connection pieces  57  projecting in parallel with each other in the shape of a cantilever from an edge of a belt-shaped carrier  56 . The bus bar  55  is held with the carrier  56  disposed along the sheet-shaped holding portion  52  and with connection pieces  57  facing the cylindrical portion  53 . Punched holes  54  are formed on the sheet-shaped holding portion  52  in correspondence to the gaps between adjacent connection pieces  57  projecting from the carrier  56 . In the process of producing the bus bar unit  50 , a portion of a carrier  56  facing each punched hole  54  is punched with a punch and die in correspondence to a predetermined connection pattern. As a result, the carrier  56  is divided (not shown) into a plurality of bus bars  55 . One bus bar  55  has at least three connection pieces  57 . A plurality of the terminals  20  are connected by each bus bar  55  through the connection pieces  57 . 
     Each bus bar unit  50  is installed on the housing  10  in a direction forward therefrom such that the cylindrical portion  53  covers the upper-row cavities  11  or the lower-row cavities  11 . When the bus bar unit  50  has been installed on the housing  10 , the connection pieces  57  are connected with the terminals  20 . Connection patterns can be discriminated from each other by, for example, changing the color of the holding member  51  of the bus bar unit  50 . The upper part of the holding member  51  and the lower part thereof are not symmetrical. Thus, the bus bar unit  50  can be installed on the housing  10  in a correct direction, and a group of the terminals  20  can be connected in a correct pattern by checking colors and directions of the holding members  51 . 
     The cap  60  is made of a relatively rigid synthetic resin material. As shown in FIG. 3, the cap  60  is oval-shaped in a front view and has a closed bottom. Locking holes  61  to which the locking projections  44  of the seal holder  40  lock are formed at the edge of the open mouth of the cap  60 . The cap  60  is locked in the installed state by the engagement between the locking projections  44  and the locking holes  61 . Relief portions  62  projecting outwardly are formed on the edge of an opening of the cap  60  to prevent the cap  60  from interfering with the index projections  45  of the seal holder  40 . The region of the inner peripheral surface of the cap  60  near the edge of its opening is formed as a sealing surface  63  with which the lip portion  34  formed on the peripheral edge of the sealing member  30  contacts elastically as shown in FIG.  10 . 
     Guide grooves  58  shown in FIG. 2, which are part of a temporary locking mechanism or detent, extend in a front to rear direction at the right and left-hand sides of the cylindrical portion  53  of each bus bar unit  50 . Front and rear locking projections  17  and  18 , which are also part of the temporary locking mechanism or detent, corresponding to each guide groove  58  are formed on the housing  10 . Each bus bar unit  50  is held at a temporary locking position whereby a rear end portion of the cylindrical portion  53  is between the locking projections  17  and  18 . The rear end portion is defined by the rear edge of the cylindrical portion  53  and the rear end of the guide groove  58  (see FIG.  5 ). Each bus bar unit  50  is held at a fully installed position by locking the front end of the guide groove  58  and the rear end thereof to the locking projections  17  and  18 , respectively, with the front and rear ends of the guide groove  58  sandwiching the locking projections  17  and  18  therebetween (see FIG.  4 ). When the bus bar units  50  are held at the fully installed position, the terminals  20  are electrically connected by the bus bars  55 . As described above, during the installation of each bus bar unit  50  on the housing  10 , the bus bar units  50  are held at the temporary locking position (see lower bus bar unit of FIG.  6  and FIG. 7) which is located forward from the fully installed position (see FIGS. 8 and 10) where the terminals are electrically connected. The temporary locking position is located rearwardly from a collision position at which the locking lances  12  would collide with the respective bus bar unit  50  if the locking lances  12  were outwardly displaced from the outer surface of the housing  10  due to an incomplete terminal insertion (see upper step of FIG.  6 ). In other words, on installation each bus bar unit  50  must pass the collision position before it arrives at the temporary locking position. Over the distance between an installation start position of the bus bar unit  50  and the temporary locking position, through the collision position between the locking lances  12  and the bus bar unit  50 , the tab pieces  57  are not in contact with the terminals  20 . 
     During assembly of the connector, an assembling jig  70  is used as shown in FIGS. 7-9. The assembling jig  70  has a function of installing the bus bar units  50  on the housing  10  and detecting the state of insertion of the terminals  20 . As shown in FIGS. 7-9, the assembling jig  70  includes a lever  72  which is supported at the right end of a substrate  71  and can be pivoted between a waiting state shown in FIGS. 7 and 9 and an assembling state shown in FIG.  8 . The assembling jig  70  also includes a pressing member  73  which is moved leftward in FIGS. 7-9 in correspondence with a pivotal motion (counterclockwise in FIGS. 7-9) of the lever  72  by a camming action of the lever  72 . The assembling jig  70  also has a stationary positioning member  74  located leftward in FIGS. 7-9 from the pressing member  73 . A return spring (not shown) biases the lever  72  and the pressing member  73  to the waiting position. The connector is placed between the pressing member  73  (located at the waiting position) and the positioning member  74 , with the bus bar units  50  set at the temporary locking position. 
     The distance between the pressing member  73  in the waiting position and the positioning member  74  is equal to or a little longer than the distance between the front ends of the bus bar units  50  when the bus bar units  50  are at the temporary locking position and the rear end of the housing  10 . Therefore, the connector cannot be set in the jig  70  if either bus bar unit  50  has not reached the temporary locking position. This is because the bus bar unit  50  interferes with the upper surface of the pressing member  73 . 
     When the lever  72  is shifted from the waiting state to the assembling state after the connector has been set in the jig  70 , the pressing member  73  moves leftward and presses the bus bar units  50  from the temporary locking position to the normal assembling position. During the movement of the bus bar units  50 , the connection pieces  57  of the bus bar units  50  contact the resilient contact pieces  23 . Consequently, the terminals  20  are connected to each other. 
     An assembly procedure is, for example, as follows. Initially, the sealing member  30  is sandwiched between the seal holder  40  and the housing  10 . At this time, a projection (not shown) formed on the housing  10  is passed through the sealing member  30  and the tip of the projection is locked to the seal holder  40 . This locks the seal member  30  to the housing  10 , and removal of the seal holder  40  is prevented. Then, the terminals  20  are inserted through the openings  41  and the holes  31  into the cavities  11 . 
     Thereafter, the bus bar unit  50  is installed at the temporary locking position on the housing  10 , and the bus bar unit  50  is placed on the assembling jig  70 . Then, by operating the lever  72  of the assembling jig  70 , the bus bar units  50  are pressed to the fully installed position from the temporary locking position. As a result, the terminals  20  are connected in a predetermined pattern. When the bus bar unit or units  50  are in the fully installed position, the connector is removed from the assembling jig  70 . Finally, the cap  60  is installed on the housing  10  in such a manner that the cap  60  covers the housing  10  and the bus bar units  50 . 
     The lip portion  34  formed on the periphery of the sealing member  30  prevents water from penetrating into the cap  60  between the inner periphery of the cap  60  and the periphery of the sealing member  30 . Further, the lip portion of the sealing hole  31  contacts the periphery of the wire  25  closely, the inner periphery of the fit-in hole  32  contacts the periphery of the holding projection  14 , and the inner periphery of the fit-in hole  33  contacts the periphery of the deformation prevention projection  15 . Therefore, water can be prevented from penetrating into the sealing member  30  from outside. 
     On installation of the bus bar unit  50  on the housing  10 , when all the terminals  20  are fully inserted into their respective cavities  1 , each locking lance  12  is undeformed so that its outer surface is flush with the outer surface of the housing  10 . Accordingly, when the cylindrical portion  53  slides over the outer surface of the housing  10  during bus bar unit-installation, the cylindrical portion  53  does not interfere with the locking lances  12 . Thus, each bus bar unit  50  can be securely installed to the temporary locking position of the housing  10 . When the bus bar units  50  have been installed on the housing  10  in the temporary locking position, the cylindrical portion  53  faces the locking lances  12  in such a manner that the inner surface of the cylindrical portion  53  presses downward on the outer surfaces of the locking lances  12 . Thus, the locking lances  12  are prevented from being elastically displaced in a direction which would move them away from the terminals  20  (see the lower bus bar unit of FIG.  6 ). 
     On the other hand, if there are any terminals  20  inserted into the cavity  11  in an incompletely inserted state, the locking lances  12  are elastically displaced outward and project outward from the outer surface of the housing  10 . During the installation of the bus bar unit  50  on the housing  10 , the front end of the cylindrical portion  53  then collides with the front end of the locking lances  12  (see upper bus bar unit of FIG.  6 ). As a result, the installation operator notices that the installation resistance is suddenly increased. In this manner, the operator can detect that a terminal  20  is in an incompletely inserted state. 
     The operator can then suspend the installation of the bus bar unit  50  on the housing  10  when the cylindrical portion  53  has collided with the locking lances  12  and resumes the installation after inserting the terminal  20  into the normal position of the cavity  11 . If the operator does not feel an increase in the installation resistance, the operation proceeds to use the assembling jig  70 . If the operator feels the installation resistance but forgets to re-insert the terminals  20 , the operator may continue with the installation despite feeling the installation resistance. In this case, the connector cannot be set on the assembling jig  70 . This alerts the operator to the fact that the bus bar unit  50  has not arrived at the temporary locking position and that one or more of the terminals  20  may have been incompletely inserted. Also, the connector cannot be set on the assembling jig  70  if the bus bar unit  50  has not reached the temporary locking position, even though all the terminals may have been inserted correctly. As is apparent from the foregoing description, if the connector cannot be set on the assembling jig  70 , incorrect assembly can be corrected by checking the installation position of the bus bar unit  50  and the inserted states of the terminals  20 . 
     As described above, during installation of the bus bar units  50  on the housing  10 , the bus bar units  50  are not subjected to an installation resistance caused by contact between the connection pieces  57  of the bus bar unit  50  and the terminal fittings  20 . After each bus bar unit  50  passes the temporary locking position, the connection pieces  57  start to contact the terminals  20 . Accordingly, it is possible to discriminate between installation resistance on the bus bar unit  50  due to the collision of the locking lance  12  and the bus bar units  50 , and installation resistance that is caused by collision between the terminals  20  and the tab pieces  57 . In this manner, it is possible to reliably detect the state of insertion of the terminals  20 . 
     If incomplete insertion of any of the terminals is noticed and it is still attempted to set the connector in the assembling jig  70 , the bus bar unit  50  will be at the position of collision between the locking lance  12  the bus bar unit  50 . Thus, it is impossible to set the connector in the assembling jig  70 . In this manner, it is detected that one or more of the terminals are incompletely inserted. That is, a mechanism is provided for detecting the incomplete insertion of a terminal  20  both during the process of installing the bus bar unit  50  on the housing  10  and during the operation of setting the connector on the assembling jig  70 . Thus, the incomplete insertion of the terminal  20  can be reliably detected. 
     The present invention is not limited to the embodiments described, but may be varied, for example, as described below. 
     (1) In the above description, a connector of waterproof type has been described. However, the present invention is also applicable to a connector of non-waterproof type. 
     (2) In the above description, incomplete insertion of the terminal is detectable during installation of the bus bar unit on the housing and during setting of the connector on the assembling jig. However, according to the present invention, it is possible to detect incomplete insertion of the terminal during installation of the bus bar unit on the housing without using an assembling jig.