Patent Publication Number: US-11050192-B2

Title: Electric connector with connector position assurance

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to an electric connector. More specifically, this invention relates to an electric connector with a connector position assurance. 
     Some types of electric machines use relatively high voltage to power components of equipment. For example, electric and hybrid cars include high voltage batteries that provide power to the drive motors. The high voltage batteries are connected to a high voltage circuit to provide current flow to the drive motors or other high voltage equipment. A high voltage disconnect is typically provided to allow the batteries to be selectively disconnected from the high voltage circuit. The high voltage disconnect includes an electric connector that can be attached and detached from a header connector. An example of a high voltage disconnect is shown in U.S. Pat. No. 7,811,115, the disclosure of which is hereby incorporated by reference in its entirety. 
     The electric connector includes electric terminals for closing the high voltage circuit, as well as low voltage electric terminals for closing a second, low voltage circuit. When the electric connector is disconnected from the header, the low voltage electric terminals are disconnected first, which opens an interlock loop. The electric terminals for the high voltage circuit are disconnected second, after a delay following the interlock loop being opened. The high voltage disconnect described in the U.S. Pat. No. 7,811,115 includes a latch that is released in multiple stages involving a thumb actuation pad and a tool actuation block. This requires the operator to take multiple steps to disconnect the electric connector for the header, which introduces the delay. 
     A controller monitors the interlock loop. When the interlock loop is opened, the controller disconnects current flow through the high voltage loop. The delay allows time for any residual voltage in the high voltage circuit to be discharged before the electric terminals for the high voltage circuit are disconnected. This helps to avoid damage to the electric terminals that could be caused by arcing of the residual voltage. When the electric connector is attached to the header, the high voltage circuit is closed first, and the interlock loop is closed second. The controller will prevent current flow in the high voltage circuit until the interlock loop is closed. 
     When the electric connector is attached to the header, the connection is sealed against moisture and other contaminants. Additionally, the connection includes electromagnetic shielding in order to prevent the current flow through the terminals from interfering with other electric components. It would be advantageous to have an alternative sealed, shielded, high voltage electric connector that includes an interlock loop. 
     SUMMARY OF THE INVENTION 
     This invention relates to an electric connector. The electrical connector includes a connector housing. A latch on the connector housing is movable between an opened position and a closed position. The electrical connector also includes a connector position assurance. The connector position assurance is supported on the connector housing for relative rotational movement about a connector axis between a locked position and an unlocked position. When the connector position assurance is in the locked position, the latch is prevented from moving from the closed position to the opened position. 
     Another embodiment of this invention relates to an electric connector assembly. The electric connector assembly includes a first electric connector with a first connector housing. The first connector housing has a latch that is movable between an opened position and a closed position. The first electric connector also includes a connector position assurance supported on the first connector housing for relative rotational movement about a first connector axis between a locked position and an unlocked position. The electric connector assembly also includes a second electric connector. The second electric connector is movable relative to the first electric connector between an initial position and a mated position. The second electric connector has a second connector housing with a connector catch. The connector catch is engaged by the latch to retain the second electric connector in the mated position when the latch is in the closed position. When the connector position assurance is in the locked position, the latch is prevented from moving from the closed position to the opened position. 
     Various aspects of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of an electric vehicle including an electric connector assembly that serves as a battery disconnect. 
         FIG. 2  is a perspective view of the electric connector assembly in accordance with this invention. 
         FIG. 3  is an exploded perspective view of a first electric connector of the electric connector assembly illustrated in  FIG. 2 . 
         FIG. 4  is an end view of a connector position assurance of the first electric connector. 
         FIG. 5  is a cross-sectional view taken along line  5 - 5  of  FIG. 4 . 
         FIG. 6  is an enlarged, perspective view of a first connector housing of the first electric connector. 
         FIG. 7  is a cross-sectional view taken along lithe line  7 - 7  of  FIG. 6 . 
         FIG. 8  is an enlarged, perspective view similar to  FIG. 6  showing the connector position assurance attached to the first connector housing and in an unlocked position. 
         FIG. 9  is a cross-sectional view taken along line  9 - 9  of  FIG. 8 . 
         FIG. 10  is a perspective view of the assembled first electric connector. 
         FIG. 11  is a cross-sectional view taken along line  11 - 11  of  FIG. 10 . 
         FIG. 12  is an exploded view of a second electric connector of the electric connector assembly. 
         FIG. 13  is an enlarged, perspective view of the assembled second electric connector. 
         FIG. 14  is an end view of a second connector housing of the second electric connector. 
         FIGS. 15A-22A  are schematic views of the relative positions of components of the electric connector assembly when the first electric connector and second electric connector are mated and unmated. 
         FIGS. 15B-22B  are schematic views of the relative positions of electric terminals of the electric connector assembly during each of the steps illustrated in  FIGS. 15A-22A . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, there is illustrated in  FIG. 1  a schematic view of a vehicle, indicated generally at  10 . The vehicle  10  includes a battery  12 . The illustrated vehicle  10  is an electric vehicle, but may be a hybrid vehicle or any desired type of vehicle that includes a battery  12 . The vehicle  10  includes an electric motor  14  that is connected to drive wheels  16 . A primary circuit, indicated generally at  18 , provides current flow from the battery  12  through the electric motor  14 . The illustrated electric motor  14  is one type of electric equipment that may be connected to the battery  12 , and it should be appreciated that any desired electric equipment may be powered by the battery  12  through the primary circuit  18 . Furthermore, the invention described herein may be used with any desired electric components and is not limited to use in vehicles. 
     The vehicle  10  includes an electric connector assembly, indicated generally at  20 . The electric connector assembly  20  serves as a battery disconnect and allows an operator to open the primary circuit  18  at the battery  12 . This could be done, for example, when the electric motor  14  is to be serviced. It should be appreciated that the primary circuit  18  is only described in a simplified form sufficient for the understanding of the electric connector assembly  20 . The preferred embodiment of the invention will be described in connection with the battery  12  on the electric vehicle  10 , but it should be appreciated that the invention may be used as an electric connector assembly in any desired circuit. 
     The illustrated electric connector assembly  20  is also part of an interlock loop, indicated generally at  22 . The interlock loop  22  is monitored by a battery control  24 . When the interlock loop  22  is open, the battery control  24  disables current flow through the primary circuit  18 . When the interlock loop  22  is closed, the battery control  24  permits current flow through the primary circuit  18 . 
     Referring to  FIG. 2 , there is illustrated a perspective view of the electric connector assembly  20 , shown in a mated position. The electric connector assembly  20  includes a first electric connector, indicated generally at  26 , and a second electric connector, indicated generally at  28 . In the illustrated embodiment, the second electric connector  28  is a header that is adapted to be attached to a battery housing (not shown), and the first electric connector  26  is a battery connector. However, the first electric connector  26  and the second electric connector  28  may be used for any desired electric connections. 
     The first electric connector  26  is connected to a shielded cable  30  that is part of the primary circuit  18 . The second electric connector  28  is connected to two second primary conductors  32  that are also part of the primary circuit  18 . The second electric connector  28  is also connected to two secondary conductors  34  that are part of the interlock loop  22 . A description of how the electric connector assembly  20  opens and closes the primary circuit  18  and the interlock loop  22  will be provided below. 
     Referring to  FIG. 3 , there is illustrated an exploded view of the first electric connector  26 . The first electric connector  26  includes a first connector housing  36  that extends along a first connector axis  38  from a mate end  40  to a cable end  42 . The illustrated first connector housing  36  is molded from plastic, but may be made of any desired material and by any desired process. The first electric connector  26  includes a connector position assurance  44  that extends from an engagement end  46  to a lock end  48 . The illustrated connector position assurance  44  is also molded from plastic, but may be made of any desired material and by any desired process. The first connector housing  36  and the connector position assurance  44  will be described in detail below. 
     The first electric connector  26  includes two first primary electric terminals  50 . The illustrated first primary electric terminals  50  are female barrel-type terminals, but may be any desired types of terminals. When the first electric connector  26  is assembled, the first primary electric terminals  50  are connected to respective first primary conductors  52  that extend from the shielded cable  30 . The first electric connector  26  also includes a shorting bar  54  that is part of the interlock loop  22 . The operation of the first primary electric terminals  50  and the shorting bar  54  will be described below. 
     The first electric connector  26  includes a ferrule  56  that is connected to the shielded cable  30 . The ferrule  56  is made of metal and extends around the circumference of the shielded cable  30 . The ferrule  56  is electrically connected to a shield layer (not shown) of the shielded cable  30  and serves to extend electromagnetic shielding from the shielded cable  30  into the first electric connector  26 , as will be described below. 
     The first electric connector  26  includes an inner housing  58 . The illustrated inner housing  58  is molded from plastic, but may be made of any desired material and by any desired process. The inner housing  58  supports the first primary electric terminals  50  and the shorting bar  54  when the first electric connector  26  is assembled. A terminal position assurance  60  is adapted to be inserted into the inner housing  58  to ensure that the first primary electric terminals  50  are properly positioned in the inner housing  58 . A spacer  62  is located adjacent to the inner housing  58  and maintains a separation between the inner housing  58  and the ferrule  56  when the first electric connector  26  is assembled. The illustrated spacer  62  is a two-part plastic component, but may be made of any desired material and by any desired method. 
     The first electric connector  26  also includes a first electromagnetic shield  64 . The illustrated first electromagnetic shield  64  is a single piece of drawn metal, but may be made of any desired material and by any desired process. The illustrated first electromagnetic shield  64  includes three cylindrically-shaped sections  66   a ,  66   b , and  66   c  and two steps  68   a  and  68   b  that are located between adjacent sections  66   a  and  66   b  and adjacent sections  66   b  and  66   c , respectively. When the first electric connector  26  is assembled, the first electromagnetic shield  64  engages the ferrule  56  to extend electromagnetic shielding from the shielded cable  30  into the first electric connector  26 , as will be described below. 
     The first electric connector  26  further includes a cable seal  70  and a housing seal  72 . Both the cable seal  70  and the housing seal  72  are elastomeric O-rings, but may be any desired type of seals. The cable seal  70  and the housing seal  72  serve to prevent moisture and contaminants from reaching the first primary electric terminals  50  and the shorting bar  54  when the electric connector assembly  20  is mated, as will be described below. 
     Referring now to  FIG. 4 , there is illustrated an end view of the connector position assurance  44 , viewed from the engagement end  46 .  FIG. 5  is a cross-sectional view taken along line  5 - 5  of  FIG. 4 . The connector position assurance  44  has a generally cylindrical shape and a circular cross-sectional shape when viewed perpendicular to the first connector axis  38 . The connector position assurance  44  includes a connector position assurance inner wall  74  that faces the first connector axis  38 . The connector position assurance  44  includes one or more assurance catches  76  that extend inwardly from the inner wall  74 . The illustrated connector position assurance  44  includes two assurance catches  76  that are located on opposite sides of the connector position assurance  44 , but may include any desired number in any desired locations. As best shown in  FIG. 3 , each assurance catch  76  is located on a respective bridge  78  on the connector position assurance  44 . Each bridge  78  is flanked by slits  80  on either side that define the bridge  78 . The slits  80  extend parallel to the first connector axis  38  and pass completely through the material of the connector position assurance  44 . The bridges  78  allow the respective assurance catches  76  to be deflected relative to the inner wall  74  when the connector position assurance  44  is attached to the first connector housing  36 , as will be described below. 
     Referring back to  FIG. 4 , the connector position assurance  44  also includes one or more assurance stops  82  that also extend from the inner wall  74 . The illustrated connector position assurance  44  includes two assurance stops  82  that are located on opposite sides of the connector position assurance  44 , but may include any desired number in any desired locations. The assurance stops  82  serve to retain the connector position assurance  44  in one of a plurality of positions relative to the first connector housing  36 , as will be described below. 
     Referring now to  FIG. 6 , there is illustrated an enlarged view of the first connector housing  36  from  FIG. 3 . In  FIG. 7  there is illustrated a cross-sectional view taken along line  7 - 7  of  FIG. 6 . The first connector housing  36  includes a housing base  84  that is located at the cable end  42 . An assurance support portion  86  extends from the housing base  84  to the mate end  40 . The first connector housing  36  includes an assurance support surface  88  on an outer side of the assurance support portion  86 . The assurance support surface  88  is the portion of the first connector housing  36  that the connector position assurance  44  is adjacent to when the first electric connector  20  is assembled, as will be described below. The assurance support surface  88  has a generally cylindrical shape and a circular cross-sectional shape viewed perpendicularly to the first connector axis  38 . 
     The first connector housing  36  includes a flange  90  that extends away from the first connector axis  38 . The flange  90  is located adjacent to the assurance support surface  88  and is located between the assurance support surface  88  and the mate end  40  of the first connector housing  36 . The flange  90  serves to retain the connector position assurance  44  on the first connector housing  36 , as will be described below. 
     The first connector housing  36  includes one or more connector position assurance retainers  92  that serve to retain the connector position assurance  44  on the first connector housing  36 . The illustrated first connector housing  36  includes two connector position assurance retainers  92  (only one is visible in  FIG. 6 ) located on opposite sides of the first connector housing  36 . However, the first connector housing  36  can include any number of connector position assurance retainers  92  in any desired locations. Each connector position assurance retainer  92  includes a resilient arm  94  and a catch  96  that extends from the arm  94  away from the first connector axis  38 . The catch  96  is located adjacent to the assurance support surface  88  between the assurance support surface  88  and the cable end  42  of the first connector housing  36 . 
     The first connector housing  36  includes one or more assurance catch slots  98  (only one is visible in  FIG. 6 ) defined in the assurance support surface  88 . The illustrated first connector housing  36  includes two assurance catch slots  98  located on opposite sides of the first connector housing  36 , but may include any desired number in any desired locations. Each of the catch slots  98  extends circumferentially around a portion of the first connector housing  36  between a first end  100  and a second end  102 . When the connector position assurance  44  is attached to the first connector housing  36 , each of the assurance catches  76  will be located in one of the assurance catch slots  98 , as will be described below. The illustrated assurance catch slots  98  extend completely through the material of the first connector housing  36 , but may have any desired depth. 
     Referring now to  FIG. 8 , there is illustrated a perspective view of the connector position assurance  44  attached to the first connector housing  36 . The connector position assurance  44  is shown in an unlocked position in  FIG. 8 . In order to attach the connector position assurance  44  to the first connector housing  36 , the connector position assurance  44  is initially positioned with its engagement end  46  facing the cable end  42  of the first connector housing  36 . The connector position assurance  44  is then moved relative to the first connector housing  36  in an attachment direction  104  so that the inner wall  74  is located on the assurance support surface  88 . 
     As the connector position assurance  44  is moved relative to the first connector housing  36 , the engagement end  46  of the connector position assurance  44  engages the catch  96  of each of the connector position assurance retainers  92  and deflects the catches  96  inwardly, toward the first connector axis  38 . The connector position assurance  44  is moved in the attachment direction  104  until the engagement end  46  engages the flange  90 . At that point, the connector position assurance  44  has been moved past the catches  96 , and the arms  94  rebound, which move the catches  96  away from the first connector axis  38 . The connector position assurance  44  is then located between the flange  90  and the catches  94 , with the inner wall  74  adjacent to the assurance support surface  88 . In the illustrated embodiment, the connector position assurance  44  includes retainer slots  106  at the lock end  48 . The retainer slots  106  are circumferential channels in the connector position assurance  44 , and each catch  94  is located in one retainer slot  106 . However, the catch  94  may be located on any desired part of the connector position assurance  44 . 
     Referring back to  FIGS. 6 and 7 , the first connector housing  36  includes one or more rotation tabs  107  that extend from the flange  90  onto the assurance support surface. The illustrated first connector housing  36  includes two rotation tabs  107  that are located on opposite sides of the first connector housing  36 , but may include any desired number in any desired locations. Referring back to  FIGS. 4 and 5 , the connector position assurance  44  includes one or more rotation slots  108  at the engagement end  46 . Each of the rotation slots  108  extends circumferentially around a portion of the first connector housing  36 . The illustrated connector position assurance  44  includes two rotation slots  108  located on opposite sides of the connector position assurance  44 , but may include any desired number at any desired locations. When the connector position assurance  44  is attached to the first connector housing  36 , each of the rotation tabs  107  is located in one of the rotation slots  108 . The connector position assurance  44  is mounted to the first connector housing  36  for relative rotation between the unlocked position (illustrated in  FIG. 8 ) and a locked position (illustrated in  FIG. 2 ). Each rotation tab  107  moves within the respective rotation slot  108  when the connector position assurance  44  is moved relative to the first connector housing  36 . The rotation tab  107  will engage an end of the respective rotation slot  108  to limit rotation of the connector position assurance  44  relative to the first connector housing  36 . 
     Referring back to  FIGS. 6 and 7 , the first connector housing  36  includes one or more rotation detents, indicated generally at  110 . The illustrated first connector housing  36  includes two rotation detents  110  that are located on opposite sides of the first connector housing  36 , but may include any desired number at any desired locations. Each of the rotation detents  110  is defined in the assurance support surface  88  and includes an unlocked detent  112 , a locked detent  114 , and an intermediate channel  116 . When the connector position assurance  44  is attached to the first connector housing  36 , each of the assurance catches  76  is located in one of the rotation detents  110 . When the connector position assurance  44  is in the unlocked position, each assurance catch  76  is located in one of the unlocked detents  112 . When the connector position assurance  44  is in the locked position, each assurance catch  76  is located in one of the locked detents  114 . The assurance catch  76  will pass through the intermediate channel  116  when the connector position assurance  44  is moved between the unlocked position and the locked position. The assurance catches  76  cooperate with the rotation detents  110  to respectively retain the connector position assurance  44  in the unlocked position and the locked position relative to the connector housing  36 . The assurance catches  76  and the rotation detents  110  also provide tactile feedback to the operator when the connector position assurance  44  has been moved to the unlocked position and to the locked position. 
     Referring back to  FIG. 5 , each assurance catch  76  includes an assurance catch release surface  118  on a side of the assurance catch  76  facing the engagement end  46 . As the connector position assurance  44  is moved relative to the first connector housing  36 , the assurance catch release surface  118  will engage the first connector housing  36 . The assurance catch release surface  118  is sloped relative to the attachment direction  104  so that as the connector position assurance  44  is moved in the attachment direction  104 , a force is applied to the assurance catch  76  that pushes the assurance catch  76  away from the first connector axis  38 . As previously described, each assurance catch  76  is located on a respective bridge  78  that allow the respective assurance catches  76  to be deflected relative to the inner wall  74 . As a result, the assurance catches  76  are deflected away from the first connector axis  38  as the connector position assurance  44  is moved relative to the first connector housing  36 . When the connector position assurance  44  has been moved to the unlocked position, each connector position assurance  44  is located in one of the assurance catch slots  98 , and the connector position assurance  44  will rebound toward the first connector axis  38 . When the connector position assurance  44  is in the unlocked position, each assurance catch  76  is located adjacent to the first end  100  of the respective assurance catch slot  98 . When the connector position assurance  44  is rotated to the locked position, each assurance catch  76  moves in the respective assurance catch slot  98  to the second end  102 . 
     Referring to  FIG. 9 , there is illustrated a cross-sectional view taken along line  9 - 9  of  FIG. 8 . The cross-section is taken along the same line as  FIG. 7 , and shows the connector position assurance  44  attached to the first connector housing  36  and in the unlocked position. 
     Referring now to  FIG. 10 , there is shown a perspective view of the assembled first electric connector  26 , with the connector position assurance shown in the unlocked position.  FIG. 11  is a cross-sectional view taken along line  11 - 11  of  FIG. 10 . In order to complete the assembly of the first electric connector  26 , the first primary electric terminals  50  and the shorting bar  54  are inserted into the inner housing  58 . The terminal position assurance  60  is inserted to retain the first primary electric terminals  50  in place. Each of the first primary electric terminals  50  is attached to onto one of the first primary conductors  52 . In the illustrated embodiment, the first primary conductors  52  are attached to the first primary conductors  52  by crimping, but any desired connection may be used. The spacer  62  is positioned between the inner housing  58  and the ferrule  56 , and the electromagnetic shield  64  is positioned around the inner housing  58 . The illustrated electromagnetic shield  64  includes shield tabs  120  (shown in  FIG. 3 ) that engage the inner housing  58  to retain the electromagnetic shield  64  in position. The first connector housing  36  is positioned around the electromagnetic shield  64 , and an end cap  122  is located around the shielded cable  30  and is attached to the first connector housing  36  adjacent to the cable end  42 . The illustrated end cap  122  is molded from plastic, but may be made of any desired material and by any desired method. 
     As illustrated in  FIG. 11 , the cable seal  70  is located between the electromagnetic shield  64  and the shielded cable  30 . The cable seal  70  is engaged with an inner surface  124  of the electromagnetic shield  64 . Additionally, the housing seal  72  is located between the electromagnetic shield  64  and the first connector housing  36 . The housing seal  72  is engaged with an outer surface  126  of the electromagnetic shield  64 . The housing seal  72  is located in a seal seat  128  that is defined between the step  68   a  of the electromagnetic shield  64  and part of the first connector housing  36 . The seal seat  128  restricts movement of the housing seal  72  in the attachment direction  104  relative to the first connector housing  36  and relative to the electromagnetic shield  64 . 
     Referring now to  FIG. 12 , there is illustrated an exploded view of the second electric connector  28 . The second electric connector  28  includes a second connector housing  130  that extends along a second connector axis  132  from a mate end  134  to a cable end  136 . The illustrated second connector housing  130  is molded from plastic, but may be made of any desired material and by any desired process. 
     The second electric connector  28  includes two second primary electric terminals  138 . The illustrated second primary electric terminals  138  are male, pin-type terminals, but may be any desired types of terminals. When the second electric connector  28  is assembled, the second primary electric terminals  138  are connected to respective ones of the second primary conductors  32 . The illustrated second primary electric terminals  138  are connected to the second primary conductors  32  by crimping, but any desired connection method may be used. The second electric connector  28  also includes two second secondary electric terminals  140  that are part of the interlock loop  22 . Each second secondary electric terminal  140  is attached to a respective secondary conductor  34 . The illustrated second secondary electric terminals  140  are also connected to the secondary conductors  34  by crimping, but any desired connection method may be used. The operation of the second primary electric terminals  138  and the second secondary electric terminals  140  will be described below. 
     The second electric connector  28  includes a second inner housing  142 . The illustrated second inner housing  142  is molded from plastic, but may be made of any desired material and by any desired process. The second inner housing  142  supports the second primary electric terminals  138  and the second secondary electric terminals  140  when the second electric connector  28  is assembled. The second electric connector  28  also includes a second electromagnetic shield  144 . The illustrated second electromagnetic shield  144  is made from two pieces sheet metal, bent to the illustrated shape. However, the second electromagnetic shield  144  may be made of any desired material and by any desired process. When the second electric connector  28  is assembled, the second electromagnetic shield  144  engages a ground (not shown) on the battery housing. 
     The second electric connector  28  also includes a header seal  146 . The header seal  146  is an elastomeric O-ring, but may be any desired type of seal. The header seal  146  serves to prevent moisture and contaminants from reaching the second primary electric terminals  138  and the second secondary electric terminals  140  when the electric connector assembly  20  is mated, as will be described below. 
     Referring to  FIG. 13 , there is illustrated a perspective view of the assembled second electric connector  28 . To assemble the second electric connector  28 , the second primary electric terminals  138  and the second secondary electric terminals  140  are positioned inside the second inner housing  142 . The second electromagnetic shield  144  is positioned around the second inner housing  142 . The second electromagnetic shield  144  is snapped inside the second connector housing  130 . The second connector housing  130  is adapted to be mounted to the battery housing using two bolts  148 . When the second connector housing  130  is so mounted, the header seal  146  is located between the second connector housing  130  and the battery housing. As previously described, the illustrated second electric connector  28  is provided for illustrative purposes, and the second electric connector  28  may be any desired type of electric connector. 
     Referring to  FIG. 14 , there is illustrated an end view of the second connector housing  120 , viewed from the mate end  134 . The second connector housing  120  has a generally cylindrical shape and a circular cross-sectional shape when viewed perpendicularly to the second connector axis  132 . The second connector housing  120  includes an outer surface  150  that faces away from the second connector axis  132 . A connector catch  152  extends from the outer surface  150 . The illustrated second connector housing  120  includes one connector catch  152 , but may include any desired number. The second connector housing  120  also includes one or more unlock stops  154  and one or more lock stops  156  that extend from the outer surface  150 . The illustrated second connector housing  120  includes two unlock stops  154  that are located on opposite sides of the second connector housing  120 , and two lock stops  156  that are located on opposite sides of the second connector housing  120 , but may include any desired number at any desired locations. The unlock stops  154  and the lock stops  156  interact with the connector position assurance  44  when the first electric connector  26  and the second electric connector  28  are unmated, as will be described below. 
     In order to mate the first electric connector  26  and the second electric connector  28 , the first electric connector  26  is initially positioned with the first connector axis  38  aligned with the second connector axis  132 , the mate end  40  facing the mate end  134 , and the connector position assurance  44  in the unlocked position. The first electric connector  26  is then moved relative to the second electric connector  28  in a mate direction  158 , so that the first electric connector  26  engages the second electric connector  28 . In the illustrated embodiment, the mate direction  158  is the same direction as the attachment direction  104 , but the mate direction  158  may have any desired relative orientation. 
     Referring back to  FIG. 9 , the first electric connector  26  includes one or more unlock channels  160  and one or more lock channels  162 . The illustrated unlock channels  160  and lock channels  162  are located in the first connector housing  36  and extend from the mate end  40  parallel to the first connector axis  38  (as shown in  FIG. 6 ). The illustrated first connector housing  36  includes two unlock channels  160  that are located on opposite sides of the first connector housing  36  and two lock channels  162  that are located on opposite sides of the first connector housing  36 , but may include any desired number at any desired locations. The illustrated unlock channels  160  and lock channels  162  pass completely through the material of the first connector housing  36 , but may have any desired depth. Each unlock channel  160  passes through one of the assurance catch slots  98  adjacent to the first end  100 . Also, each lock channel  162  passes through one of the assurance catch slots  98  adjacent to the second end  102 . 
     The first electric connector  26  also includes one or more latch channels  164 . The illustrated latch channel  164  is located in the first connector housing  36  and extends from the mate end  40  parallel to the first connector axis  38 . The illustrated first connector housing  36  includes one latch channel  164 , but may include any desired number at any desired locations. The illustrated latch channel  164  passes completely through the material of the first connector housing  36 , but may have any desired depth. 
     When the first electric connector  26  is mated with the second electric connector  28 , the first electric connector  26  is oriented so that each of the unlock stops  154  enters one of the unlock channels  160 , and so that each of the lock stops  156  enters one of the lock channels  162 . Additionally, the first electric connector  26  is oriented so that the connector catch  152  enters the latch channel  164 . As previously described, the illustrated embodiment includes only one connector catch  152  and one latch channel  164 . As a result, the first electric connector  26  and the second electric connector  28  can only be mated when they are located in one desired relative orientation. If the first electric connector  26  and the second electric connector  28  are not located in the desired relative orientation, then the connector catch  152  will engage the mate end  40  of the first connector housing  36  and prevent further movement in the mate direction  158 . Thus, the connector catch  152  serves as an orientation feature for the electric connector assembly  20 . 
     As best shown in  FIG. 8 , the first electric connector  26  includes a lever  166 . The lever  166  is attached to the first connector housing  36  at a pivot bar  168  and is able to deflect relative to the housing base  84 . The lever  166  includes a press surface  170  that is located on one side of the pivot bar  168  and a latch  172  that is located on the opposite side of the pivot bar  168 . The latch  172  is located in the latch channel  164 . The lever  166  is adapted to be actuated by the operator by applying a force to the press surface  170  to move the lever  166  from a closed position (shown in  FIG. 8 ) to an opened position. 
     Referring to  FIG. 15A , there is illustrated a schematic, cross-sectional view of a portion of the electric connector assembly  20 .  FIG. 15A  illustrates a side view of the first connector housing  36  and shows the unlock channel  160 , the lock channel  162  and the latch channel  164  extending from the mate end  40 . The assurance catch slot  98  and the rotation detent  110 , as well as the latch  172  are also illustrated.  FIG. 15A  also illustrates the relative locations of parts of the second electric connector  28  including the connector catch  152 , the unlock stop  154 , and the lock stop  156 . Finally,  FIG. 15A  illustrates the relative locations of parts of the connector position assurance  44  including the assurance catch  76  and the assurance stop  82 . 
       FIG. 15A  shows the electric connector assembly  20  in the initial position, wherein the first electric connector  26  is positioned with the first connector axis  38  aligned with the second connector axis  132 , the mate end  40  facing the mate end  134 , and the connector position assurance  44  in the unlocked position. The first electric connector  26  is shown before it is engaged with the second electric connector  28 . 
     Referring to  FIG. 15B , there is illustrated a schematic view of a terminal assembly, indicated generally at  174 . The terminal assembly  174  includes the first primary electric terminals  50 , first secondary electric terminals  176 , the second primary electric terminals  138 , and the second secondary electric terminals  140 . The first secondary electric terminals  176  are located on the shorting bar  54 .  FIG. 15B  shows the relative positions of these electric terminals in the terminal assembly  174  when the electric connector assembly  20  is in the initial position and none of the electric terminals is mated. At this point the primary circuit  18  is open and the interlock loop  22  is open. 
     Referring to  FIG. 16A , there is illustrated a view similar to  FIG. 15A  showing the first electric connector  26  moved from the initial position in the mate direction  158  relative to the second electric connector  28 . As previously described, the unlock stop  154  enters the unlock channel  160 , the lock stop  156  enters the lock channel  162 , and the connector catch  152  enters the latch channel  164 . Because the connector position assurance  44  is in the unlocked position, the assurance catch  76  is located adjacent to the first end  100  of the assurance catch slot  98 . As previously described, the unlock channel  160  passes through the assurance catch slot  98  adjacent to the first end  100 . As a result, the assurance catch  76  engages the unlock stop  154 . 
     As previously described, the assurance catch release surface  118  (shown in  FIG. 5 ) is located on the side of the assurance catch  76  facing the engagement end  46  of the connector position assurance  44 . When the first electric connector  26  is moved in the mate direction  158  relative to the second electric connector  28 , the unlock stop  154  engages the assurance catch release surface  118  of the assurance catch  76 . The force applied to the assurance catch release surface  118  by the unlock stop  154  pushes the assurance catch  76  away from the first connector axis  38 . As a result, the first electric connector  26  can continue to be moved in the mate direction  158  relative to the second electric connector  28 . 
     Referring to  FIG. 17A , there is illustrated a view similar to  FIG. 16A  showing the first electric connector  26  after having been moved farther in the mate direction  158  relative to the second electric connector  28 . As shown, the connector catch  152  has moved in the latch channel  164  and has engaged the latch  172 . Referring back to  FIG. 11 , the latch  172  includes a latch release surface  178  that is sloped relative to the mate direction  158  so that the connector catch  152  will apply a force to the latch  172  and push the latch  172  away from the first connector axis  38  and out of the latch channel  164 . As a result, the lever  166  will be moved to the open position, and the first electric connector  26  can continue to be moved in the mate direction  158  relative to the second electric connector  28 . 
     Referring to  FIG. 18A , there is illustrated a view similar to  FIG. 17A  showing the first electric connector  26  after having been moved farther in the mate direction  158  relative to the second electric connector  28 .  FIG. 18A  shows the electric connector assembly  20  in the mated position, wherein the first electric connector  26  is mated with the second electric connector  28 . The connector catch  152  has been moved past the latch  172 , and the latch  172  has rebounded into the latch channel  164 . 
       FIG. 18B  illustrates the state of the terminal assembly  174  when the electric connector assembly  20  is in the mated position. When the electric connector assembly  20  is in the mated position, the first primary electric terminals  50  are mated with the second primary electric terminals  138 , and the primary circuit  18  is closed. Additionally, the first secondary electric terminals  176  are mated with the second secondary electric terminals  140 , and the interlock loop  22  is closed. 
     The first electric connector  26  is moved relative to the second electric connector  28  in a single motion from the initial position (illustrated in  FIG. 15A ) to the mated position (illustrated in  FIG. 18A ). Thus, the operator may align the first electric connector  26  with the second electric connector  28  and push the first electric connector  26  in the mate direction  158 . The assurance catch  76  and the latch  127  will deflect and rebound without any additional action on the part of the operator. 
     Referring to  FIG. 19A , there is illustrated a view similar to  FIG. 18A  showing the connector position assurance  44  after having been moved relative to the first electric connector  26  to the locked position. The electric connector assembly  20  is then in a locked position illustrated in  FIG. 2 . The connector position assurance  44  includes a latch block  180  that prevents the latch  172  from moving to the opened position when the connector position assurance  44  is in the locked position. As shown in  FIG. 2 , the illustrated latch block  180  is a portion of the connector position assurance  44  that is located adjacent to the lever  166  in the radial direction. Thus, when the connector position assurance  44  is in the locked position, the latch block  180  prevents the latch  172  from being moved radially away from the first connector axis  38  and out of the latch channel  164 . 
     When the electric connector assembly  20  is in the locked position, a force applied to the first electric connector  26  to move it opposite the mate direction  158  relative to the second electric connector  28  is resisted by the connector catch  152  engaging the latch  127 . Additionally, this force is resisted by the lock stops  156  engaging the assurance catches  76 . As previously described, when the connector position assurance  44  is in the locked position, the assurance catch  76  is located adjacent to the second end  102  of the assurance catch slot  98 . 
     Referring back to  FIG. 5 , the assurance catch  76  includes an assurance catch stop surface  182  that is located on the opposite side from the assurance catch release surface  118 . The illustrated assurance catch stop surface  182  extends substantially perpendicularly to the first connector axis  38  and the mate direction  158 . As a result, the force applied to the assurance catch stop surface  182  in the mate direction  158  will not push the assurance catch  76  away from the first connector axis  38 . 
     In order to unmate the first electric connector  26  from the second electric connector  28 , the connector position assurance  44  is moved to the unlocked position. This is schematically illustrated in  FIG. 20A . The electric connector assembly  20  is still in the mated position previously described in reference to  FIGS. 18A and 18B . 
     From the mated position, the latch  172  may be moved out of the latch channel  164 . In the illustrated embodiment, the latch  172  is moved by the operator applying a force to the press surface  170 , which moves the lever  166  from the closed position to the open position. However, any desired type of release mechanism for the latch  172  may be used. With the latch  172  in the open position, the first electric connector  26  is moved relative to the second electric connector  28  opposite the mate direction  158 . The first electric connector  26  may be moved until the unlock stop  154  engages the assurance catch  76 . This is schematically illustrated in  FIG. 21A . The unlock stop  154  engages the assurance catch stop surface  182  and, as a result, the assurance catch  76  is not moved out of the unlock channel  160 . Thus, further movement of the first electric connector  26  relative to the second electric connector  28  opposite the mate direction  158  is blocked. The electric connector assembly  20  is then in an interlock open position. 
     Referring to  FIG. 21B , when the electric connector assembly  20  is in the interlock open position, the first primary electric terminals  50  are mated with the second primary electric terminals  138 , and the primary circuit  18  is closed. However, the first secondary electric terminals  176  are disconnected from the second secondary electric terminals  140 , and the interlock loop  22  is open. 
     As best shown in  FIG. 10 , the connector position assurance  44  includes a latch space  184  that the latch  172  moved into when the latch  172  is in the open position. The illustrated latch space  184  is a U-shaped opening that opens onto the lock end  48  of the connector position assurance  44 . However, the latch space  184  may have any desired shape. When the latch  172  is in the open position, the latch  172  will engage the connector position assurance  44  to prevent the connector position assurance  44  from moving from the unlocked position to the locked position. Referring to  FIG. 10 , when the press surface  170  is pressed down toward the first connector axis  38 , the latch  172  is moved upwardly away from the first connector axis  38 . If an attempt is made to rotate the connector position assurance  44  to the locked position, the latch block  180  on the connector position assurance  44  will engage the latch  172  and prevent movement of the connector position assurance  44 . When the latch  172  returns to the closed position, the connector position assurance  44  may be moved relative to the first connector housing  36 . 
     Referring back to  FIG. 21A , with the electric connector assembly  20  in the interlock open position, the latch  172  is moved to the closed position, and the connector position assurance  44  is then moved to the locked position. This is illustrated schematically in  FIG. 22A . The assurance catch  76  is moved to the second end  102  of the assurance catch slot  98  and, thus, no longer blocks movement of the unlock stop  154 . From this position, the first electric connector  26  is moved relative to the second electric connector  28  opposite the mate direction  158  back to the initial position (illustrated in  FIG. 15A ). 
     The first electric connector  26  is moved relative to the second electric connector  28  in a multiple-stage motion from the mated position (illustrated in  FIG. 20A ) to the initial position (illustrated in  FIG. 15A ). Thus, a delay is introduced between when the interlock loop  22  is opened and when the primary circuit  18  is opened. 
     In normal use of the electric connector assembly  20 , the connector position assurance  44  is moved to the unlocked position before the first electric connector  26  is mated with the second electric connector  28 . If the connector position assurance  44  is in the locked position when the first electric connector  26  is aligned with the second electric connector  28  and moved in the mate direction  158 , the connector catch  152  will engage the latch release surface  178  of the latch  172 , but will be unable to push it out of the latch channel  164 . This would be the state of the electric connector assembly  20  illustrated in  FIG. 22A , wherein the assurance catch stop surface  182  prevents the latch  172  from moving out of the closed position. 
     When the electric connector assembly  20  is in the mated position illustrated in  FIG. 2 , the electromagnetic shield  64  in the first electric connector  26  is engaged with the second electromagnetic shield  144  in the second electric connector  28 . This provides a continuous electromagnetic shield from the shielded cable  30  to the battery housing. Additionally, the housing seal  72  in the first electric connector  26  is engaged with the second connector housing  130  of the second electric connector  28 . 
     The principle and mode of operation of this invention have been explained and illustrated in its preferred embodiment. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.