Abstract:
The present invention relates to an electrical connector assembly and a method to assemble the same. The electrical connector assembly includes a plug connector that is configured to be mated with a corresponding counter-connector. The plug connector includes a connector housing having a guiding feature and a locking device being arranged movable relative to the connector housing. The locking device has a guiding member and a flexible arm. The flexible arm is configured to be flexed during mating the plug connector with the corresponding counter-connector such that the locking device can be moved into a locked position. The guiding feature and the guiding member are configured to guide the locking device from a first position to a locked position so that the flexible arm is reflexed when the locking device is in the locked position.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit under 35 U.S.C. §119(a) of Patent Application No. 16172635.1 filed in the European Patent Office on Jun. 2, 2016, the entire disclosure of which is hereby incorporated by reference. 
       TECHNICAL FIELD OF THE INVENTION 
       [0002]    The present invention relates to an electrical connector assembly with a locking device. 
       BACKGROUND OF THE INVENTION 
       [0003]    The safe coupling of connectors is of high importance for many applications. For example, modern passenger cars include a variety of different electrical connections. For ensuring that connectors mated with a corresponding counter-connector cannot become loose unintentionally, additional locking devices are known in the art to guarantee a safe mechanical coupling between the connector and counter-connector. These locking devices are often referenced as secondary locking devices and are provided as a separate element. 
         [0004]    Further, it is also desirable to indicate, either visually or physically, that a plug connector has been fully and properly mated with a corresponding counter-connector during the assembly procedure for allowing a “fool-proof” assembly. In order to reduce the risk associated with improperly mated connectors, so-called connector position assurance (CPA) devices have been developed. Such CPA devices are separate elements, which can be inserted into a connector housing of a plug connector. When the connector is not properly or fully coupled to its corresponding counting connector, the CPA device cannot be fully inserted into the connector housing. Accordingly, the CPA device protrudes from the connector, indicating that full mating has not been accomplished yet. Only upon full and proper mating of the connector with the counter-connector, it is possible to fully insert the CPA device into the connector housing. This allows to visually indicating whether the plug connector has been properly and correctly mated with the counter-connector. Often, the functionalities of CPA devices and secondary locking devices are integrated in one part. 
         [0005]    However, particularly in small connector designs, the integration of CPA devices and/or locking devices is challenging. This is due to the restricted construction space. Therefore, CPA devices and/or locking devices have to be very small, resulting in slender locking features, such as locking arms. However, slender locking features are prone to damage. 
         [0006]    Previous designs have addressed this issue by providing shortened and slender locking features that are more rigid. However, providing more rigid locking features will lead to increased strain when the locking features are used in conventional snap or latch locking connections. Therefore, also shortened and slender locking features are prone to damage. 
         [0007]    Further, in modern manufacturing sites, it is often desired that a plug connector is mated with a counter-connector in a fast and secure manner. This need arises among others out of economic reasons. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    Thus, it is an object of the present invention to provide a CPA device and/or locking device that is more robust. It is hence desired that the mating procedure can be accomplished with a minimal number of steps. It is therefore a further object of the present invention to provide an electrical connector assembly which allows for a fast and secure mating of a plug connector with a counter-connector. 
         [0009]    The object of the invention is achieved by an electrical connector assembly according to claim  1  and a method to assemble an electrical connector assembly according to claim  15 . 
         [0010]    In particular, the object is achieved by an electrical connector assembly including a plug connector that is configured to be mated with a corresponding counter-connector. The plug connector includes a connector housing having a guiding feature, and a locking device being arranged movably relative to the connector housing, wherein said locking device includes a guiding member and a flexible arm. The flexible arm is configured to be flexed during mating the plug connector with the corresponding counter-connector such that the locking device can be moved into a locked position. The guiding feature and the guiding member are configured to guide the locking device from a first position to a locked position so that the flexible arm is reflexed when the locking device is in the locked position. 
         [0011]    The locking device is configured to ensure that the connector is mated with a corresponding counter-connector correctly and cannot become loose unintentionally. Preferably, the locking device is pre-assembled with the connector housing before the plug connector is mated with a corresponding counter-connector. Thus, the locking device is partially inserted into or generally engaged with the connector housing. Alternatively, the plug connector can be mated with a corresponding counter-connector and the locking device is inserted into the connectors housing after the mating process. 
         [0012]    The locking device is guided by the guiding feature and the guiding member from a first position to a locked position. In the locked position, the locking device improves the mating between the connector and the corresponding counter-connector. Further, by guiding the locking device so that the flexible arm is reflexed when the locking device is in the locked position, strain that is applied on the flexible arm during flexing is released again. Consequently, there is no or at least reduced strain on the flexible arm in the locked position, compared to a conventional locking device and/or a conventional CPA device. Therefore, the locking device is less prone to damage and can achieve a longer lifespan. 
         [0013]    Preferably, the plug connector is configured to be mated with a corresponding counter-connector along a mating direction. Further, the guiding feature is preferably a stepped guiding feature so that the locking device is guided by the guiding feature along the mating direction and in a second direction that is different from the mating direction, in order to reflex the flexible arm when the locking device is in the locked position. 
         [0014]    In particular, the stepped guiding feature guides the locking device when the locking device is moved from a first position to the locked position along the mating direction and in a second direction that is different from the mating direction. The guiding in the second direction is achieved by a step provided in the stepped guiding feature. Particularly, the stepped guiding feature is provided with at least two surface portions that are offset to each other in the second direction. Said surface portions are connected via a connecting surface so that a guiding member can be guided along, e.g. by sliding along, the surface portions. 
         [0015]    For example, when the flexible arm is flexed in the second direction by a certain deflection, the locking device is guided in second direction by an amount that compensates said deflection. Thus, the flexible arm is reflexed when the locking device is in the locked position. The deflection is preferably in the range of 0.1 mm to 2.5 mm, more preferably in the range of 0.5 mm to 2.2 mm and most preferably in the range of range of 0.6 mm to 1.0 mm. 
         [0016]    Further, preferred, the guiding feature is an angled guiding feature, wherein a first surface portion extends along the mating direction, to provide a guiding along the mating direction. A second angled surface portion is angled to the first surface portion and extends along the second direction, to provide a guiding along the second direction. Thus, the locking device can be guided in second direction by an amount that compensates the deflection of the flexible arm. 
         [0017]    Preferably, the guiding feature at least partially receives the guiding member when the locking device is in the first position. With receiving the guiding member in the guiding feature, the locking device can be pre-assembled in the first position. This will facilitate the mating process of the connector with a corresponding counting connector and a subsequent movement of the locking device in the locked position. Since the locking device is at least partly engaged with the connector housing, i.e. by features of received guiding members, the starting point of the movement of the locking device into the locked position is defined. 
         [0018]    Preferably, the guiding feature includes a guiding recess and/or a guiding gap and the locking device includes a guiding arm, which arm preferably extends parallel to the flexible arm, wherein the guiding arm is configured to be inserted into the recess and/or the gap. A guiding arm that extends parallel to the flexible arm will protect the flexible arm, as long as the locking device is not fully inserted into the connector housing. 
         [0019]    Further, a guiding arm that is inserted into a guiding recess and/or a guiding gap of the connector housing will guide the locking device from a first position to a locked position, thereby supporting and facilitating the movement. Primarily the guiding arm is a stepped guiding arm facilitating the guiding in conjunction with a stepped guiding feature. Particularly, the guiding recess and/or guiding gap of the guiding feature is designed so that only one particular guiding arm, which is characteristic for the locking device, can be inserted. Therefore, an unintentionally assembly of an incorrect locking feature can be prevented. 
         [0020]    Preferably the guiding feature includes a locking recess and/or a locking gap, wherein the locking recess and/or the locking gap includes a locking portion. Further, the locking device includes a locking protrusion, preferably arranged on the guiding arm, wherein the locking protrusion is configured to be inserted into the locking recess and/or the locking gap and to be locked with the locking portion when the locking device is in the locked position. 
         [0021]    The locking between the locking protrusion and the locking portion when the locking device is in the locked position, prevents an unintentional removal of the locking device from the locked position. For example, the locking between the locking portion and the locking protrusion can be a latched locking, a bayonet locking and/or the like. 
         [0022]    The locking recess and/or locking gap as well as the guiding recess and/or guiding gap of the guiding feature are preferably provided in a wall of the housing. They can be formed as a through opening or a groove having a certain depth. The depth of the groove is preferably in the range of 0.1 to 2.5 mm, even more preferably in the range of 0.5 to 2 mm and most preferably in the range of 0.7 to 1.5 mm. 
         [0023]    Preferably the connector housing includes a retention portion, preferably provided within the locking recess and/or the locking gap, wherein the retention portion is configured to engage the locking device, and preferably configured to engage the locking protrusion so as to constrain a movement of the locking device in a direction opposite to the mating direction when the locking device is in the first position. 
         [0024]    A retention portion facilitates the pre-assembly of the locking device with the connector housing, since the locking device is retained in the connector housing in the first position. Thus, the locking device cannot be unintentionally removed from the connector housing. Thus, it can be guaranteed that the locking device is positioned correctly before and/or during the mating process of the plug connector. Further, with providing a retention portion within the locking recess, the locking protrusion of the locking device can be used to secure the locking device in the connector housing, therefore the design of the locking device is facilitated; i.e. no additional retention protrusion or the like has to be provided. 
         [0025]    Preferably the guiding feature includes a guiding surface being provided on an outer surface of the connector housing, wherein the locking device includes a guiding protrusion, preferably arranged on the guiding arm, wherein the guiding protrusion is configured to engage with the guiding surface in the first position and the locked position. 
         [0026]    With providing a guiding surface on an outer surface of the connector housing, no recesses or gaps have to be provided in a wall of the connector housing in order to provide a guiding functionality. Thus, the connector housing is not weakened by a guiding recess or a gap. This is in particular advantageous when very small connector housings shall be provided. It has to be noted that the guiding recesses or guiding gaps as well as the locking recesses or locking gaps as well as the guiding surfaces can be provided as single guiding feature. Alternatively, multiple guiding features and/or multiple different guiding features can be provided, as described above. Particularly, providing multiple different guiding features improves the guiding of the locking device in the connector housing so that the movement of the locking device from the first position to the locked position is facilitated. For example, the locking device is less prone for being jammed or blocked when being moved from the first position to the locked position. 
         [0027]    Preferably the first position is a pre-locked position, and the flexible arm and the connector housing are configured to be in blocking contact, if the locking device is arranged in the pre-locked position so as to inhibit movement of the locking device from the pre-locked position into the locked position, wherein the flexible arm is preferably not flexed in the pre-locked position. 
         [0028]    Inhibiting the movement of the locking device from a pre-locked position to a locked position guarantees that the locking device is not moved to the locked position before the connector is correctly mated with the counter-connector. Thus, the locking device can serve as connector position assurance (CPA) device. In this case, the locking device can be moved to the locked position, if the flexible arm is flexed so that the blocking contact is released and the movement of the locking device from the pre-locked position into the locked position is no longer inhibited. 
         [0029]    Preferably, the locking device includes a blocking protrusion and the connector housing includes a corresponding blocking projection, wherein said blocking protrusion and said blocking projection are configured to provide the blocking contact between the flexible arm and the connector housing. Preferably, the flexible arm transfers forces acting in mating direction onto the locking device along said flexible arm in longitudinal direction thereof and via the blocking projection and the blocking protrusion, provided in the connector housing, onto the connector housing so as to inhibit movement of the secondary locking device from the pre-locked position into the locked position. Providing a blocking projection and a corresponding blocking protrusion allows to define force application points so that the flexible arm and/or the connector housing can be designed strain optimized with regard to said force application points. Thus, the overall live span of the connector housing and/or the locking device can be increased. 
         [0030]    Preferably, the flexible arm of the locking device includes a releasing protrusion that is configured to engage with the counter-connector to thereby flex the flexible arm during mating the plug connector with the corresponding counter-connector such that the locking device can be moved into the locked position. Providing a releasing protrusion that can engage with the counter-connector to thereby flex the flexible arm, will release the flexible arm from the blocking contact with the connector housing in order to allow the movement of the locking device into a blocked position. Thus, the locking device can be used as a CPA device, indicating a correct coupling of the connector with the corresponding counter-connector. The releasing protrusion can be an inclined surface that can slide along a portion of the counter-connector, in order to flex the flexible arm. 
         [0031]    Preferably, the connector housing includes a flexible lever, having a primary locking feature configured to provide a primary locking function when the plug connector is mated with a corresponding counter-connector, wherein the primary locking function preferably can be unlocked when said flexible lever is flexed. Providing a flexible lever having a primary locking feature allows to lock the connector housing to a corresponding counter-connector, independent of the presence of the locking device. Thus, for example, the plug connector can be mated and locked with the corresponding counter-connector and the locking device can be inserted afterwards. By providing an unlock-functionality, the plug connector can be removed from the corresponding counter-connector, without any damages. If no unlock-functionality is provided, the plug connector can be permanently locked to the counter-connector, which is desirable in certain applications. 
         [0032]    Preferably, the locking device includes a primary jamming portion provided on the flexible arm, wherein the primary jamming portion is configured to block an unlock movement of the primary locking feature when the locking device is in the locked position. Providing a jamming portion that blocks an unlock movement of the primary locking feature will secure and maintain the primary locking between the plug connector and the corresponding counter-connector. Consequently, as long as the locking device is in its locked position, the risk of unintentionally loosening of the locking between the plug connector and the corresponding counter-connector can be reduced. 
         [0033]    Preferably, the locking device includes a secondary jamming portion, wherein the secondary jamming portion is preferably an element separate from the flexible arm. When the locking device is in the first and/or pre-locked position, the secondary jamming portion does not engage the flexible lever of the connector housing. When the locking device is moved from the first and/or pre-locked position to the locked position, said secondary jamming portion engages the flexible lever of the connector housing at least partially to prevent a flexing of said flexible lever. 
         [0034]    With providing a secondary jamming portion, the blocking of an unlock movement of the primary locking feature can be improved. Since the unlock movement of the primary locking feature requires a flexing of the flexible lever, a blocking of the flexing of the flexible lever also prevents an unlock movement of the primary locking feature. Thus, the primary locking of the plug connector with the counter-connector can be additionally secured. Preferably, the primary jamming portion and the secondary jamming portion are provided as redundant portions. This can be achieved by providing the secondary jamming portion as an element separate from the flexible arm. Thus, the blocking of the unlock movement can be effectively guaranteed. 
         [0035]    Preferably, the mating of the plug connector to the corresponding counter-connector is achieved by applying a pressing force on the locking device in the mating direction, wherein the locking device is configured to be moved from the first to the locked position by further applying said pressing force. Allowing to mate the plug connector with a corresponding counter-connector by applying a pressing force on the locking device and subsequently or simultaneously moving the locking device from a first position to the locked position by further applying of the pressing force, allows to mate the plug connector with the corresponding counter-connector and move the locking device in the locked position in one assembly step. Thus, assembly time can be reduced. This is in particular relevant for industrial applications, such as industrial or automobile assembly lines. 
         [0036]    The object of the invention is further achieved by a method to assemble the electrical connector assembly as previously described, wherein the method includes the steps of:
       providing a connector housing, including a guiding feature;   providing a locking device, including a guiding member and a flexible arm;   arranging the locking device in a first position to form a plug connector, wherein the guiding feature receives the guiding member at least partially;   mating the plug connector with a corresponding counter-connector, and thereby flexing the flexible arm of the locking device such that the locking device can be moved into the locked position;   moving the locking device into the locked position, wherein the guiding feature guide the locking device from the first position to the locked position so that the flexible arm is reflexed when the locking device is in the locked position.       
 
         [0042]    The above described method allows to provide additional locking functionality to secure the plug connector and the corresponding counter-connector and to use the locking device as a CPA device, indicating the correct coupling of the plug connector with the corresponding counter-connector. 
         [0043]    Preferably, the mating of the plug connector to the corresponding counter-connector is achieved by applying a pressing force on the locking device in the mating direction, and wherein the locking device is moved from the first position to the locked position by further applying said pressing force. As previously described, applying a pressing force for mating the plug connector and for moving the locking device in the locked position facilitates the assembly and helps to reduce assembly time and therefore costs. 
         [0044]    These and other objects, which become apparent by reading the following description, are achieved by the present invention according to the subject matter of the independent claims. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0045]    The present invention will now be described, by way of example with reference to the accompanying drawings, in which: 
           [0046]      FIG. 1  is an exploded view of an electrical connector assembly; 
           [0047]      FIG. 2  is a schematic view of a locking device; 
           [0048]      FIG. 3  is a schematic sectional view of the plug connector, wherein the locking device is removed; 
           [0049]      FIG. 4  is a schematic cut view of the plug connector with the locking device being in a first position before assembly; 
           [0050]      FIG. 5A  is a schematic view of the locking device being in a pre-locked position; 
           [0051]      FIG. 5B  is a schematic view of the locking device being in a pre-locked position; 
           [0052]      FIG. 5C  is a schematic cut view of the plug connector with the locking device being in a pre-locked position; 
           [0053]      FIG. 5D  is a further cut view of the plug connector of  FIG. 5C ; 
           [0054]      FIG. 6A  is a schematic cut view of the plug connector and the counter-connector; 
           [0055]      FIG. 6B  is a schematic cut view of the plug connector and the counter-connector; 
           [0056]      FIG. 6C  is a schematic detailed cut view of the primary jamming portion; 
           [0057]      FIG. 7A  is a schematic side view of the plug connector and the corresponding counter-connector; 
           [0058]      FIG. 7B  is a schematic side view of the plug connector and the corresponding counter-connector; 
           [0059]      FIG. 7C  is a schematic side view of the plug connector and the corresponding counter-connector; and 
           [0060]      FIGS. 8A and 8B  are detailed cut views of the second jamming portion. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0061]      FIG. 1  shows a non-limiting example of a plug connector, wherein the plug connector includes a locking device  10 , a connector housing  20 , a terminal collector  30 , a first sealing device  40 , an inner housing  50 , a second sealing device  60  and a terminal position assurance device (TPA)  70 . The components  10 ,  20 ,  30 ,  40 ,  50 ,  60 ,  70  can be assembled to form a plug connector. That plug connector can be mated with the corresponding counter-connector  80 . The inner housing  50  is configured to receive single electrical terminals or electrical pins (not shown) of the plug connector. The TPA device  70  can only be inserted into the inner housing  50 , if all terminals and/or pins are correctly collected and installed within the terminal collector  30 . Preferably, the terminal collector  30  provides protection to the first sealing device  40  when the first sealing device  40  is received in the terminal collector  30 . 
         [0062]      FIG. 2  shows an exemplary embodiment of the locking device  10 . The locking device  10  includes a flexible arm  12  that extends in the mating direction and is arranged between two guiding arms  11   a ,  11   b . The guiding arms are stepped guiding arms that are used as guiding members of the locking device  10 . Further, on the side surfaces of each guiding arm  11   a ,  11   b  and locking protrusions  13   a ,  13   b  are arranged. These locking protrusions  13   a ,  13   b  are used as guiding members and provide a locking functionality when engaging with a corresponding locking recess or a corresponding locking gap as described herein later. Further, a stepped guiding protrusion  15   a ,  15   b  is provided on a side surface of the corresponding guiding arms  11   a ,  11   b . These stepped guiding protrusion  15   a ,  15   b  are used as guiding members and therefore configured to guide the locking device  10  from a first position to a locked position. 
         [0063]    Further, the flexible arm  12  includes a blocking protrusion  17  for providing a blocking contact between the flexible arm  12  and the connector housing  20 . The flexible arm  12  further includes a releasing protrusion  19  for releasing the blocking contact between the blocking protrusion  17  and the connector housing  20 . The releasing protrusion  19  includes an inclined surface. The primary jamming portions  16  are provided at a distal end of the flexible arm  12  and are configured to block an unlock movement of the primary locking feature of the connector housing  20 . 
         [0064]      FIG. 3  shows a partial cut view of the plug connector, wherein the top cover of the connector housing  20  is not shown. Further, the locking device is not shown in FIG.  3 . The connector housing  20  includes a flexible lever  26  having a primary locking feature  29 . The primary locking feature  29  can engage with a primary locking projection provided on a corresponding counter-connector. The flexible lever  26  can be flexed in order to engage with the primary locking projection of the corresponding counter-connector, as will be described in greater detail later on. Further, the inner housing  50  and the second sealing device  60  are shown in  FIG. 3 . 
         [0065]      FIG. 4  shows a schematic view of the plug connector, wherein the locking device  10  is removed from the connector housing  20 . The connector housing  20  includes a flexible lever  26 . Further, the connector housing  20  includes a variety of different guiding feature. Firstly, two guiding recesses  21   a ,  21   b  are provided. These guiding recesses are configured to receive the guiding arms  11   a ,  11   b  of the locking device  10 . Secondly, two locking gaps  23   a ,  23   b  are provided. The locking gaps  23   b  are provided in a wall of the connector housing and are formed as through openings. Said locking gaps  23   b  are provided with a retention portion  28   b  and a locking portion  24   b . The locking gap  23   b  receives the locking protrusion  13   b  and guides the same from a pre-locked position into the locked position of the locking device. In the pre-locked position, the locking protrusion  13   b  engages with the retention portion  28   b  to secure the locking device  10  from being removed from the connector housing  20 . In the locked position of the locking device, the locking protrusion  13   b  engages with the locking portion  24   b  so as to provide an additional locking. Thirdly, the connector housing is provided with guiding surfaces  25   a ,  25   b  being provided on an outer surface of the connector housing  20 . The guiding surfaces  25   a ,  25   b  can engage with guiding protrusions  15   a ,  15   b  to guide the locking device from the first position to the locked position. 
         [0066]    In  FIGS. 5A to 5D , the pre-locked position of the locking device is illustrated. Same reference numbers relate to same elements. As shown in  FIG. 5A , the locking device  10  is at least partially inserted into the connector housing  20  in the pre-locked position. Thus, the guiding arms  11   a ,  11   b  are at least partially received in the guiding recesses  21   a ,  21   b . Further, the guiding protrusions  15   a  and  15   b  engage with the corresponding guiding surfaces  25   a ,  25   b . As can be best seen in  FIG. 5B , the locking protrusion  13   b  engages with the retention portion  28   b  to prevent the locking device  10  from being unintentionally removed from the connector housing  20 . Further, the locking gap  23   b  includes a locking portion  24   b  that is formed as a latching protrusion for providing a latch locking between the locking device  10  and the connector housing  20  in the locked position. 
         [0067]      FIG. 5C  is a cut view of the plug connector, wherein the flexible arm  12  of the locking device  10  is cut along its longitudinal axis. The blocking protrusion  17  of the flexible arm  12  is in blocking contact with the blocking projection  27  of the connector housing  20 , thus preventing a movement of the locking device  10  from the pre-locked position into the locked position. Further, the flexible arm  12  is provided at its distal end with a primary jamming portion  16  and a releasing protrusion  19 . Further, the locking device  10  includes a secondary jamming portion  18 . The secondary jamming portion  18  prevents the flexible lever  26  of the connector housing  20  to be flexed, if the locking device  10  is in the locked position. In the pre-locked position as shown in  FIG. 5C , the flexible lever  26  can be flexed so that a primary locking between the primary locking feature and a primary locking projection of a corresponding counter-connector can be unlocked.  FIG. 5D  shows the plug connector in a further cut view. The guiding arms  11   a ,  11   b  are at least partially received in the guiding recesses  21   a ,  21   b.    
         [0068]      FIGS. 6A to 6C  show the movement of the locking device  10  from a first position or a pre-locked position ( FIG. 6A ) to a locked position ( FIG. 6C ). In  FIG. 6A , the plug connector is in the pre-locked position, as described in greater detail with respect to  FIGS. 5A to 5D . The blocking protrusion  17  and the blocking projection  27  are in blocking contact, preventing the locking device  10  from being moved to the locked position. Further, the plug connector, includes the locking device  10 , the connector housing  20 , the terminal collector  30 , first and second sealing devices  40 ,  60 , the TPA device  70  and the inner housing  50 . Particularly, the plug connector is about to be mated with a corresponding counter-connector  80 . The corresponding counter-connector includes a primary locking projection  89 . 
         [0069]    When the plug connector is correctly mated with the corresponding counter-connector  80 , as shown in  FIG. 6B , the releasing protrusion  19  of the flexible arm  12  of the locking device  10  engages with the counter-connector  80  so that the flexible arm  12  is flexed in a direction substantially perpendicular to the mating direction x, i.e. in the second direction z. By applying a force onto the locking device  10  in the mating direction x, the flexible arm  12  can be flexed and the locking contact between the blocking protrusion  17  and the blocking projection  27  is released so that the locking device  10  can be moved to the locked position. As can be seen in  FIG. 6B , the primary locking feature  29  of the flexible lever  26  engages with the primary locking projection  89  of the corresponding counter-connector  80 . 
         [0070]    As shown in  FIG. 6C , when the locking device  10  is in the locked position, the primary jamming portion  16  of the flexible arm  12  blocks an unlock movement of the primary locking feature  29 . Thus, the locking between the plug connector and the corresponding counter-connector is secured. 
         [0071]      FIGS. 7A to 7C  show the movement of the locking device  10  from a first position and/or a pre-locked position to a locked position. In  FIG. 7A , the locking device  10  is shown in the pre-locked position. The locking protrusion  13   b  is received within the locking gap  23   b , wherein the locking protrusion  13   b  engages with the retention portion  28   b . Thus, the locking device  10  is prevented from being removed from the connector housing  20  unintentionally. If the plug connector is correctly mated with the corresponding counter-connector  80 , the locking device  10  can be moved to the locked position. 
         [0072]    As shown in  FIG. 7B , by applying a force in the mating direction x, the locking device  10  is guided by the guiding feature  23   b ,  25   b , i.e. the locking gap  23   b  and the guiding surface  25   b  along the mating direction x and in a second direction z that is different, in particular perpendicular to the mating direction x. Thus, the flexible arm  12  of the locking device  10  (not shown) is reflexed and no or at least reduced strain is applied on the flexible arm  12 , if the locking device  10  is in the locked position. 
         [0073]      FIG. 7C  shows locking device  10  in the locked position. The locking protrusion  13   b  engages with the locking portion  24   b  of the locking gap  23   b , thereby securing the locking device  10  in the locked position. 
         [0074]    Besides the blocking of an unlock-movement of the primary locking feature  29  of the flexible lever  26 , the flexing of the flexible lever  26  can be prevented as shown in  FIGS. 8A and 8B .  FIGS. 8A and 8B  show detailed cut views of the secondary jamming portion  18  that is provided on the locking device  10 . As shown in  FIG. 8A , the secondary jamming portion  18  is provided beneath the flexible lever  26  opposite to the primary locking feature  29 . Thereby, a flexing of the flexible lever  26 , that would result in an unlock movement of the primary locking feature  29 , is prevented. Further, as shown in  FIG. 8B , also a lateral portion of the flexible arm  12  engages with the flexible lever  26  when the locking device  10  is in the locked position, in order to prevent a flexing of the flexible lever  26  and to inhibit an unlock-movement of the primary locking feature  29 . 
         [0075]    While this invention has been described in terms of the preferred embodiments thereof, it is not intended to be so limited, but rather only to the extent set forth in the claims that follow. Moreover, the use of the terms first, second, primary secondary, etc. does not denote any order of importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. 
       LISTING OF THE REFERENCE NUMBERS 
       [0000]    
       
           1  Electrical connector assembly 
           10  Locking device 
           11   a, b  Guiding arms 
           12  Flexible arm 
           13   a, b  Locking protrusion 
           15   a, b  Guiding protrusion 
           16  Primary jamming portion 
           17  Blocking protrusion 
           18  Secondary jamming portion 
           19  Releasing protrusion 
           20  Connector housing 
           21   a, b  Guiding recess 
           23   a, b  Locking gap 
           25   a, b  Guiding surface 
           26  Flexible lever 
           27  Blocking projection 
           28   b  Retention portion 
           29  Primary locking feature 
           30  Terminal collector 
           40  First sealing device 
           50  Inner housing 
           60  Second sealing device 
           70  Terminal position assurance device 
           80  Corresponding counter-connector 
           89  Primary locking projection 
         x Mating direction 
         z Second direction