Patent Publication Number: US-11652314-B2

Title: Sealed electrical connector

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims benefit of priority to European Patent Application No. 20166439.8 filed in the European Patent Office on Mar. 27, 2020, the entire disclosure of which is hereby incorporated by reference. 
     TECHNICAL FIELD OF THE INVENTION 
     The invention relates to the field of sealed electrical connector assemblies and in particular to supplemental restraint system (SRS) plug connectors or airbag squib connectors. The invention further relates to a corresponding method for coupling an electrical connector assembly. An electrical connector assembly according to the invention is typically used in vehicles, particularly in the vehicle electrical system. 
     BACKGROUND 
     Electrical connector systems are used for joining electrical circuits, wherein typically a male contact terminal is mated with a female contact terminal. In vehicles, such as cars, multiple electrically driven supplemental restraint systems (SRS) are needed to ensure an optimal interplay of safety components (e.g., between the airbag and the pretensioner of the safety belt) in an event of an accident. 
     A failure of SRS components may lead to severe consequences for road users involved in an accident, and it is accordingly strived to provide the electrical connector systems such that it can be ensured that they work in a reliable and error-free manner. Since electrical connectors in vehicles often have small dimensions, so called connector position assurance (CPA) members are often provided, which can aid a user to ensure a proper alignment of any parts of the electrical connector. Even further it is desirable that the electrical connection established by respective connectors are protected from any disadvantageous environmental impacts, such as debris and moisture. Several approaches are known in the prior art to provide sealed connector assemblies. 
     U.S. Pat. No. 7,997,940 B2 discloses an electrical connector assembly for an airbag ignitor, wherein a plug member further includes an annular gasket seal around a plug nose and under a plug body, said seal being configured to seal the gap between a socket member and a plug member when the plug member is inserted into the socket member aperture. 
     U.S. Pat. No. 9,337,571 B2 discloses a sealing member, configured to be installed to an outer peripheral surface of a first connector housing among a pair of connector housings so as to seal a gap between the outer peripheral surface of the first connector housing and an inner peripheral surface of a second connector housing among the pair of the connector housings. An inner peripheral surface of the sealing member is formed with protrusions and grooves which are aligned with a first wavelength in an axial direction of the sealing member, an outer peripheral surface of the sealing member is formed with protrusions and grooves which are aligned with a second wavelength in the axial direction. The first wavelength is equal to or smaller than the second wavelength, and positions of the protrusions of the inner peripheral surface are shifted from positions of the protrusions of the outer peripheral surface in the axial direction. 
     According to the approaches of the prior art, relatively high forces must be applied by a user to mate, close and/or seal the respective electrical connectors. Further, in the approaches according to the prior art, a user closing the electrical connector by a pushing movement often experiences irregular forces when flexible seals are employed due to the additional frictional and compressive forces. 
     SUMMARY 
     A sealed electrical connector assembly is presented herein. The sealed electrical connector assembly includes a first connector member and a second connector member, wherein the first connector member is configured to be arrangeable in an open position and a sealed position, wherein, in the sealed position. The first connector member is fully mated and sealed with the second connector member. The first connector member includes a first connector member sealing wall extending essentially in a first direction, and wherein the second connector member includes a second connector member sealing wall extending essentially in the first direction, wherein in a sealed position, the first connector member sealing wall and the second connector member sealing wall face each other in a sealing region, a flexible sealing element, wherein, in the sealed position, the flexible sealing element is configured to be arranged between and contacting the sealing walls of the first connector member and the second connector member in the sealing region, wherein the flexible sealing element is fixed with respect to one of the sealing walls and configured to be releasably engageable with another one of the sealing walls for providing a watertight seal, wherein the sealing wall for releasably engaging the flexible sealing element is slanted with respect to the first direction along an entire sealing region. 
     Thus, a sealed electrical connector assembly can be obtained which protects in a sealed position housed parts from any undesired environmental impacts such as debris and moisture while employing a low seal mating force. A sealed electrical connector assembly according to the present invention may include any suitable connector assembly known in the art such as for example sealed connectors including connector position assurance (CPA) and/or terminal position assurance (TPA) members, sealed connectors couples for instance formed by male and female connectors, which can be for instance directly mated, e.g. by a latch, or which may include a mating assistance such as a lever or slider. The sealed electrical connector assembly may allow to obtain a water resistance value sufficient to obtain a protection from ingressing moisture. The plug connector may be a male or a female connector, including at least one, typically at least two electrical elements, for electrically connecting electrical components, such as electrical components of a vehicle electrical system. If there are more than two electrical contacts the connector may be used additionally for signaling purposes. The electrical elements may be an electrical consumer, a power source, a cable and/or a cable harness. 
     The first connector member and/or the second connector member may be formed as one integral part, for instance by a molding process, or may be formed by multiple parts which are assembled together. The second connector member and the first connector member may be formed in a circular manner, such that the first connector member could be received in a circular aperture of the second connector member. Accordingly, the non-slanted sealing wall may be in the form of a cylinder and the slanted sealing wall may be in the form of a cone. Even further, both sealing walls may be formed in a slanted manner. Accordingly, the flexible sealing element may be in the form of a circular ring which may be fixed to the non-slanted sealing wall. Thus, the flexible sealing element may be provided in form of a mounted seal ring, which may be accordingly fixed or mounted by tension and/or friction with the non-slanted sealing wall. The sealing element may include any suitable flexible material, which allowing a respective sealing function when compressed. Nonlimiting examples may include elastomers such as thermoset elastomers for example rubber and silicone. Further examples may include thermoplastic elastomers and urethanes. The shape and size of the flexible sealing element may be suitably configured such that a smooth movement of the first connector member or any other counterpart relative to the second connector member is provided when the flexible sealing element is compressed during a sealing movement, which also may be referred to as a mating or closing movement. The respective parts may be preassembled such that the preassembled plug connector already includes the first connector member in an open position, which is then mated with a corresponding counter-connector. The open position of the first connector member is to be understood as a position, wherein no sealing functionality is provided. Ever further, also the flexible sealing element may be provided with the second connector member or the first connector member in a preassembled manner. The flexible sealing element may include any suitable form that allows a proper compression during an engagement such as one or more bulges or lips. The sealing wall may be slanted in a way that a constant inclination angle is provided in the first direction, which also may be referred to as the closing or mating direction and the form of the flexible sealing element may be configured to this inclination to allow a preferably constant and homogenous force build-up during the sealing movement of the first connector member without any undesired intermediate force peaks which may mislead a user to the assumption that the first connector member is already arranged in a sealed position, which also may be referred to as a mated or closed position. Even further, the elements of the sealed electrical connector assembly according to the present invention prevents the need for high pushing forces when the first connector member is moved by a user into its sealed position, which may allow a user to obtain a quicker and less tiring establishment of respective electrical connections. Accordingly, the sealed electrical connector assembly according to the present invention may be particularly reliable. The slanted sealing wall may also include a lead-in chamfer that facilitates the correct initial positioning of the flexible sealing element with the slanted sealing wall. Thus, a sealed electrical connector assembly may be obtained, which allows overcoming negative impacts such as one or more undesired force peaks originating mainly from normal force components that work axially against the first direction. Even further, additional friction caused by the flexible sealing element may be reduced. Thus, the assembly according to the present invention allows avoiding counteracting forces occurring in the axial direction but also in the radial direction. 
     In a preferred embodiment, the flexible sealing element includes at least two compressible lips extending towards the slanted sealing wall, wherein the at least two compressible lips are configured such that a compression for the at least two compressible lips is essentially the same in the sealed position. 
     Accordingly, a homogenous force distribution across the flexible sealing element can be obtained. This avoids a one-sided load of only one lip, which may cause damage and/or malfunctioning. This may of course also apply to a higher number of lips such that the respective force accordingly distributes homogenously across the lips. Also, the compressible lips may be formed in a way that an engagement of the compressible lips with the slanted sealing wall is configured such that force peaks due to deformation of said lips may be prevented. The provision of suitably formed compressible lips, which are configured in form and/or material with regard to a respective optimized contact and compression with a slanted sealing wall allows to configure a respective deformation of the lip and a frictional contact force which may occur when a lip contacts the respective sealing wall. The size of the lips may be accordingly configured to the slanted sealing wall surface and may be for instance different for each lip such that the pressure on the surface of the slanted sealing wall in the sealed condition, which may be referred to as a closed or mated condition, is the same for each lip. 
     In a preferred embodiment, an angle of the slanted sealing wall is 1 to 20°, preferably 3 to 15° and most preferred 5 to 10°. 
     The angle, which may also be referred to as inclination angle, is provided relative to the first direction of the first connector member, which may be along a vertical axis. This inclination angle may be constant along the entire slanted sealing wall. Thus, variations of resulting forces may be prevented when the first connector member is moved from the open position to the sealed position. The surface inclination of the flexible sealing element may be accordingly configured to provide sufficient contact with the slanted sealing wall to safeguard sealing functionality. The selection of the slant angle being larger or smaller may be chosen dependent on the need for a low mating force (small angle), a short necessary travel distance (larger angle), sufficient lip compression (larger angle) and a low tendency of the first connector member or other parts to unintendedly move against the first direction (small angle). 
     In a preferred embodiment, the flexible sealing element is fixed with respect to the second connector member sealing wall, and configured to be releasably engageable with the first connector member sealing wall. 
     This may allow for a preassembly of the flexible sealing element with the second connector member. Thus, the second connector member and the sealing element may be provided as one preassembled element, and the first connector member may be subsequently inserted in respective apertures of the second connector member. In further embodiments according to the present invention, the flexible sealing element may be provided in a preassembled manner with the first connector member, which forms accordingly a preassembled element, which may subsequently be inserted in respective apertures of the second connector member. This may facilitate assembly of the sealed electrical connector assembly according to the present invention. 
     In a preferred embodiment, the contact between the flexible sealing element and the slanted sealing wall is formed such that a compressive sealing reaction force against the first direction is essentially constantly increasing when the first connector member is moved from the open to the sealed position. 
     Thus, any undesired force peaks, which may be experienced by a user pushing the first connector member into its sealed position could be prevented. Further, a constantly increasing force may allow a connector assembly, wherein it is easier to estimate respective compensation forces that may be desired and accordingly provided by respective means to compensate the compressive sealing reaction force. The avoidance of force peaks may also prevent damage and wear of the parts encountering said force. Within this specification, reaction force is meant to be the force which a user may experience when pushing the first connector member into the sealed position. Thus, the compressive sealing reaction force should be understood as the force experienced by a user due to the compression of the flexible sealing element and its respective friction with the second connector member sealing wall and the first connector member sealing wall. 
     In a preferred embodiment, the first connector member further includes at least one force feedback element, and wherein the second connector member includes a second connector member housing, wherein the second connector member housing includes at least one force feedback counter element configured to engage the at least one force feedback element when moving the first connector member towards the sealed position. An engagement between the at least one force feedback element and the at least one force feedback counter element is formed such that a force feedback can be provided to a user when the first connector member is moved to the sealed position. 
     Accordingly, a user may unambiguously derive from the force feedback experienced during mating and/or closing, when the first connector member is arranged in a fully sealed position. Thus, intermediate force peaks can be avoided and any intermediate first connector member positions, which may lead to an incomplete first connector member positioning and thus to an incomplete sealing of the connector assembly may be prevented. This improves reliability of the sealing during mating and/or closing. Even further the compressive sealing reaction force acting on the first connector member against the first direction may be at least partly compensated. 
     Compensation of a reaction force is to be understood such that the force, which must be applied by a user to overcome the frictional force and the compressive force of the sealing element, is compensated. Accordingly, when a high compressive force of the flexible sealing element is present, this would result in a high respective reaction force. However, although the compressive force may even further increase when moving the first connector member towards its sealed position, as the flexible sealing element is compressed further, a user may be facilitated to overcome this reaction force and may be facilitated to push the first connector member further in the first direction. Thus, the extra force which may be caused by the flexible sealing element may be compensated. The force feedback element(s) and the corresponding force feedback counter element(s) may be formed from any suitable flexible material, such as plastic. The above noted force feedback configuration may be provided as a separate locking means or in addition to further locking means, such as for instance traditional locking latches that may be provided between corresponding male and female housings. Even further, the arrangement may be configured such that two symmetrical flexible members would work symmetrically against a central “rigid” member. In this case, the “rigid” member would be loaded symmetrically, and thus would not need additional support or guiding force. This would lead to a reduction of friction. 
     In a preferred embodiment, the first connector member is configured to be moveable about a first connector member closing path distance from the open position to the sealed position, wherein the at least one force feedback element and the at least one force feedback counter element are formed to allow that, in the last 10%, preferably in the last 20% of a first connector member closing path distance of the first connector member, a resulting reaction force acting on the first connector member becomes minimum. In a preferred embodiment, the first connector member closing path distance of the first connector member from the open position towards the sealed position is up to 20 mm, preferably up to 10 mm, more preferably up to 5 mm and most preferably up to 2.6 or 2.7 mm. 
     Thus, the force level of the force feedback elements may advantageously reduce or cancel out the force level due to the seal, which can occur due to on compression and friction, at the end of the first connector member movement. According to the present invention, the force feedback may be provided such that a big force difference between a maximum positive force value at a beginning of a closing movement and a minimum force value at the end of the movement, which can still be a positive force value, can be obtained. Thus, a strong force decrease during the movement can be achieved, which leads to an improved force feedback. In a further preferred embodiment, a resulting reaction force acting on the first connector member becomes negative such that the first connector member is urged towards the sealed position. Accordingly, a user may be facilitated in completing the sealing movement of the first connector member. It is to be understood that a reaction force experienced by a user which acts against his or her pushing force may be denoted with a positive sign. Thus, if the reaction force is negative, it is to be understood that a force acts in a direction such that the first connector member is urged towards its sealed position without the need of a further pushing by a user. Thus, the first connector member may snap automatically into its sealed position and a misalignment in an intermediate position may be prevented. As an example, if the first connector member has to be moved for a total distance of 10 mm from an open position towards a sealed position, the first connector member may snap for instance at the last 20% of a total distance, which corresponds to 2 mm, into the sealed position. That is the first connector member travels the last 2 mm towards the sealed position with no further force applied from a user. Of course, also other absolute or relative first connector member closing path distance values may be employed, as desired. 
     In a preferred embodiment, the at least one force feedback element of the first connector member is a rigid member extending in the first direction, wherein the rigid member includes a bulge provided at a central portion of the rigid member, wherein the bulge protrudes towards the at least one force feedback counter element. The at least one force feedback counter element is a flexible locking member extending against the first direction and including a contact head arranged at a distal end of the flexible locking member, wherein the contact head protrudes towards the at least one force feedback element. It should be understood that the flexible locking member may also be oriented in a different direction than the first direction, as long as a suitable interaction between the flexible locking member and a respectively formed counterpart can be enabled. For instance, the flexible locking member may be formed as a horizontally oriented arm. In a preferred embodiment, when the first connector member is moved from the open to the sealed position in the first direction, the flexible locking member is configured to:
     a. initially engage the bulge of the rigid member with the contact head at a contact portion,   b. deflect due to the engagement with the bulge while the movement continues, and   c. flexibly return to its initial position after the contact portion has passed a maximum protruding width of the bulge, wherein the deflected contact head urges the bulge in the first direction towards the sealed position.   

     Accordingly, respective forces may be applied to the first connector member, which may allow for the above noted snapping functionality. The contact portion is understood as the region where contact between the bulge and the contact head occurs. Of course, also the above noted configuration may be provided vice-versa such that the force feedback element(s) of the first connector member may be provided as one or more flexible member(s) and the force feedback counter element(s) of the second connector member housing may be provided as one or more rigid member(s) or both parts may be provided as flexible members, as long as a suitable force distribution can be provided that may allow for a force feedback and/or compensation during the sealing movement of the first connector member. As the skilled person appreciates, the amount of “rigidity” and “flexibility” of the two members may be of course dependent for instance on the materials and the sizes and shapes of the respective members. That is, the rigid member may also be allowed to slightly deflect to some extent. However, the flexible member will be understood as the member that deflects to a larger extent compared to the deflection of the rigid member during engagement of the two members. The bulge and the contact head may also be provided at other suitable portions of the force feedback element(s) of the first connector member or the force feedback counter element(s) of the second connector member, respectively. 
     In a preferred embodiment, the electrical connector assembly is configured to provide a haptic feedback to a user pushing the first connector member towards the sealed position when the first connector member has reached its sealed position. 
     Thus, a user may unambiguously distinguish if the first connector member has reached its final sealed position. Accordingly, a misalignment of any parts of the sealed electrical connector assembly according to the present invention due to an incomplete first connector member positioning may be prevented. This feedback may also be instead of or in addition to any further suitable indications, such as a visual indication or acoustic indication such as a clicking sound when the first connector member has reached its sealed position. The haptic feedback may also be different to a “click” effect when the final position is reached. The haptic feedback may accordingly be a sudden drop of force after a steep raise, which may occur before the first connector member reaches its final position. Such behavior may provide a certain inertia effect, which allows avoiding an incomplete mating position. 
     In a preferred embodiment, one of the connector members is a plug connector, preferably an SRS plug connector or an airbag squib connector. Such kind of connectors are currently used for instance in airbag systems of cars. However, the present invention is not limited to this application but may be employed in any suitable electrical connector application. 
     In a preferred embodiment, an engagement between the first connector member, the flexible sealing element and the second connector member housing is formed such that a resulting reaction force acting on the first connector member, when the first connector member is moved from an open position to a sealed position along a first direction:
     a. assumes positive values in the beginning of the first connector member movement such that the resulting reaction force acts in a direction against the first direction,   b. continuously increases until the resulting reaction force reaches a single maximum value, and then   c. continuously decreases until the resulting reaction force assumes a minimum value in the sealed position.   

     Thus, a steep force increase may be provided at the beginning of the movement with a maximum value, which may be between one third to one half of the movement before a constant decrease of the force to the end of the movement may be obtained. According to the present invention, the minimum force value in step c.) may remain positive at the end of the movement. This may occur for instance due to high friction or disadvantageous space constraints. According to the present invention the engagement of the first connector member and the second connector member may be configured such that a big force difference between the single maximum force value of step b.) and the minimum force value at the end of the movement in step c) may be obtained. Thus, a strong force decrease during the movement can be achieved, which leads to an improved force feedback. In a preferred embodiment the reaction force in step c.) assumes negative values such that the resulting reaction force acts in a direction towards the first direction urging the first connector member into the sealed position. Thus, the force may advantageously become negative at the end of the movement so as to close the last few fractions of the distance on its own, as already discussed above. A high maximum force value may be important to give a stronger feedback to a user and to make use of inertia effects in order to ensure a complete closing operation. In general, force variations may occur because of any tolerances of components especially in a multi cavity mold. These force variations may impair an unambiguous haptic feedback to a user, which however could be avoided by the sealed electrical connector assembly according to the present invention. 
     In a preferred embodiment, the sealing wall for releasably engaging the flexible sealing element is slanted with respect to the first direction along the entire sealing region such that width of the sealing wall for releasably engaging the flexible sealing element continuously decreases along the first direction. 
     Thus, any variations in the reaction forces due to different slant angles may be prevented which may further improve the sealing functionality, reliability of the sealed electrical connector assembly and the ability to provide an improved and unambiguous haptic user feedback which is free from any undesired force peaks. 
     In a preferred embodiment, the first connector member is a connector position assurance, CPA, member, the second connector member is a plug connector and the first direction is a CPA member closing direction. 
     The CPA member may thus ensure for a proper alignment of the respective mechanical and/or electrical parts of the electrical connector according to the present invention and may be configured to interrupt an electrical connection between a respective plug connector and a respective counter-connector as long as the CPA member is not placed in a properly sealed position. This facilitates a user to verify a proper alignment of the respective mechanical and electrical parts and a proper locking. 
     In a preferred embodiment, the first connector member is a counter-connector, the second connector member is a corresponding plug connector and the first direction is a connector assembly mating direction. 
     Thus, the above-described functionality of providing a watertight seal can be obtained between a plug connector and a corresponding counter-connector when mating the plug connector with a corresponding counter-connector. 
     In a further embodiment according to the present invention, a watertight seal may be provided between the CPA member and the plug connector when the CPA member is in the sealed position and a further watertight seal may be provided between the plug connector and the corresponding counter-connector when the plug connector is in the sealed position, wherein the respective watertight seals can be obtained as described above with regard to the above-described embodiments. 
     A skilled person will understand that the above noted preferred embodiments are described as mere examples and that the electrical connector assembly may of course include embodiments that can be a combination of the above noted features or include a different configuration than the embodiments described within this specification. 
     Further, the present invention particularly proposes a method for coupling an electrical connector assembly, including the steps of:
     a. providing an electrical connector assembly according to one of the embodiments described above;   b. moving the first connector member from the open to the sealed position for providing an electrical connection and a watertight seal.   

     Thus, an employment of the electrical connector assembly according to the present invention may provide the above-described advantages. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will now be described, by way of example with reference to the accompanying drawings, in which: 
         FIG.  1    schematically shows a cross sectional view of an electrical connector assembly according to the present invention, wherein the first connector member is a CPA member in an open position; 
         FIG.  2    schematically shows a cross sectional view of an electrical connector assembly according to the present invention wherein the first connector member is a CPA member in a sealed position; 
         FIGS.  3 A- 3 D  schematically shows a flexible sealing element during a displacement of a connector position assurance (CPA) member of an electrical connector assembly according to the present invention; 
         FIG.  3 E  schematically shows a reaction force originating from a flexible sealing element during a displacement of a CPA member in an electrical connector assembly according to the present invention; 
         FIG.  4    schematically shows a cross sectional close-up view of a force feedback element and a force feedback counter element of an electrical connector assembly according to the present invention wherein a CPA member is in an open position; 
         FIG.  5    schematically shows a reaction force and corresponding engagement positions of a force feedback element and a force feedback counter element of an electrical connector assembly according to the present invention; 
         FIG.  6    schematically shows reaction forces originating from a flexible sealing element and a CPA member and a resulting total reaction force during a displacement of a CPA member in an electrical connector assembly according to the present invention; 
         FIG.  7    schematically shows a cross sectional close-up view of a force feedback element and two force feedback counter elements of an electrical connector assembly according to the present invention wherein a CPA member is in an open position. 
         FIG.  8    schematically shows a cross sectional view of an electrical connector assembly according to another embodiment of the present invention, wherein the first connector member is a plug connector in an open position; 
         FIG.  9    schematically shows a cross sectional view of an electrical connector assembly according to another embodiment of the present invention wherein the first connector member is a plug connector in a sealed position; and 
         FIGS.  10 A- 10 C  schematically show a flexible sealing element during a displacement of a plug connector of another embodiment of an electrical connector assembly according to the present invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG.  1    shows a cross sectional view of an electrical connector assembly according to the present invention when the first connector member, which is shown as a connector position assurance (CPA) member  20  in an open position. A second connector member is shown as a plug connector  10 , which is configured to mate with a corresponding counter-connector  60 , which together form a sealed electrical connector assembly  1 . The counter-connector  60  is shown in a disconnected state, whereas it should be understood that it may of course be provided being mated with the plug connector  10 . The plug connector  10  includes a second connector member housing  30 , which is shown as a connector housing  30 , which encloses any further parts of the plug connector  10 , such as electrical components. An electrical cable  12  is connected to the plug connector  10  and provides an electrical connection to further components which are connected to the sealed electrical connector assembly  1 . The plug connector  10  further includes the CPA member  20 , which is arranged to be received by the connector housing  30 . In this embodiment, the CPA member  20  and the connector housing  30  are formed in a circular manner. The CPA member  20  is able to move along a first or closing direction  100  into a sealed position, whereas the connector housing  30  and its respective parts remain in a fixed position. The CPA member  20  includes a first connector member sealing wall  22 , which is shown as a CPA member sealing wall  22  at its top side, which extends essentially along the closing direction  100 . The CPA member sealing wall  22  is slightly slanted along the closing direction  100 , such that it has a cone-shaped appearance. On the top side of the CPA member a pushing surface is provided, which allows a user to push the CPA member  20  in the closing direction  100  about a first connector member closing path distance  28 , which is shown as a CPA member closing path distance  28  from an open to a sealed position. The slanted CPA member sealing wall  22  is received by a respective aperture on the top side of the connector housing  30 , which has, in this embodiment, a circular appearance. The inner wall of the circular receiving aperture, which forms a second connector member sealing wall  32 , which is shown as a connector housing sealing wall  32  is provided with a flexible sealing element  50  which includes two compressible lips  52 , which are configured such that the slanted CPA member sealing wall  22  can slide along said compressible lips  52  when the CPA member  20  is pushed into the sealed position. 
     The CPA member  20  further includes inner parts which facilitate the mating and alignment of mechanical and electrical parts of the plug connector  10  and the counter-connector  60 , such as a force feedback element  24 . This force feedback element  24  extends from the top of the CPA member in the closing direction  100  towards the counter-connector  60  and has a bulge  26 , which is configured to engage a respective contact head  36  of a force feedback counter element  34  of the connector housing  30 . The connector housing  30  forms a respective chamber, in which the force feedback element  24  can move downwards in the closing direction  100 , when the CPA member  20  is accordingly pushed. 
       FIG.  2    schematically shows a cross sectional view of the electrical connector assembly of  FIG.  1    according to the present invention when the CPA member  20  is in a sealed position. Again, the counter-connector  60  is shown being connected to the plug connector  10  to establish an electrical connection. After the plug connector  10  and the counter-connector  60  have been mated, the CPA member  20  is brought into the sealed position, which allows the CPA member  20  to align any mechanical and electrical parts in the sealed electrical connector assembly  1  and thus allows to ensure a safe connection. As can be seen the CPA member  20  has been pushed towards the closing direction  100 . The CPA member sealing wall  22  has been moved along the compressible lips  52 , which are arranged and compressed in the sealing region  40 , which is the region wherein the watertight seal between the CPA member sealing wall  22  and the connector housing sealing wall  32  is formed. The contact head  36  is latched behind the recess of the bulge  26 . 
       FIGS.  3 A- 3 D  shows compressible lips  52  of the flexible sealing element  50  during a displacement of a CPA member  20  of a sealed electrical connector assembly  1  according to the present invention. The progress of movement is depicted in  FIGS.  3 A- 3 D , such that the CPA member  20  moves along the closing direction  100  and travels across the CPA member closing path distance  28  from  FIGS.  3 A- 3 D . The flexible sealing element  50  is fixed to the connector housing  30 .  FIG.  3 E  shows a corresponding force-path-diagram depicting the reaction force occurring during progression of the CPA member movement in the closing direction  100 . The slanted CPA member sealing wall  22  decreases in width W 2  along the closing direction  100 , which is illustrated by an angle α in  FIG.  3 D , with respect to the closing direction  100 , which is the vertical direction. The slanted CPA member sealing wall  22  includes a lead-in chamfer  23 , which is slanted to facilitate a lead-in of the flexible sealing element  50 .  FIG.  3 A  shows the situation when the upper compressible lip of the compressible lips  52  is already in contact with the slanted CPA member sealing wall  22 . However, the upper one of the compressible lips  52  was not engaged by the lead-in chamfer  23  but directly contacted the slanted CPA member sealing wall  22  when the CPA member  20  was pushed towards the closing direction  100 . This is reflected by the corresponding reaction force diagram of  FIG.  3 B , wherein the compressive sealing reaction force F 1  constantly rises as the upper lip is constantly further compressed. In  FIG.  3 B , the lower one of the compressible lips  52  only slightly contacts the CPA member sealing wall  22 .  FIG.  3 D  shows the CPA member  20  in a final and fully sealed position, wherein the flexible sealing element  50  is compressed in the sealing region  40  between the CPA member sealing wall  22  and connector housing sealing wall  32 . The corresponding compressive sealing reaction force F 1  is maximum in this position. As can be seen from  FIG.  3 E , no significant force peaks are provided by the engagement between the flexible sealing element  50  and the CPA member sealing wall  22  when the CPA member  20  is moved into the sealed position. The overall force level is relatively low, since the compressible lips  52  are accordingly formed to fit the slanted CPA member sealing wall  22 . As shown, the compressible lips are not compressed to the maximum in the beginning of the movement. The main contact pressure is applied at the last third of the CPA member movement. 
       FIG.  4    shows a cross sectional close-up view of a force feedback element  24  and a force feedback counter element  34 , when the CPA member  20  is in an open position. As shown, the contact head  36  of a force feedback counter element  34  is formed by a connector housing  30 . The contact head  36  is arranged between a latching protrusion  27  and a bulge  26  of a force feedback element  24 , wherein the bulge  26  has a maximum protrusion width W 1 . 
     As is further shown in  FIG.  5   , the contact head is configured to slide flexibly along the outer surface of the force feedback element  24  when the CPA member  20  is moved from an open to a sealed position along the closing direction  100 . Respective positions of the bulge  26  of the force feedback element  24  and the contact head  36  of the force feedback counter element  34  during a closing movement are shown in the  FIG.  5   . The contact portion  38  is shown as the region where contact between the bulge  26  and the contact head  36  occurs. In the beginning of the movement, the contact head  36  is flexibly deflected by the rigid bulge  26 . The reaction force from the force feedback element F 2  of said engagement, which is shown in  FIG.  5    accordingly increases and reaches a maximum value at around 0.8 mm displacement. At the end of the first ramp angle, when the radius to maximum width W 1  starts, as shown in the leftmost portion of  FIG.  5   , the force starts decreasing. To avoid a further force increase when movement continues, the contact head  36  is provided with a backward angle on its front face which is non-vertical when relaxed and vertical when bent. After passing the maximum width W 1  of the bulge  26 , the force F 2  further decreases until it gets negative, which means that the CPA member  20  no longer needs to be pushed in the closing direction  100  but the contact head  36  flexibly returns to its initial position such that it urges the bulge  26  in closing direction  100  until the CPA member  20  has reached its sealed position. 
       FIG.  6    shows reaction forces F 1  and F 2  originating from the compression of a flexible sealing element  50  and from the engagement of a CPA member  20  with the connector housing  30 , respectively, and a resulting total reaction force F 3  along a displacement of a CPA member  20  in a sealed electrical connector assembly  1  according to the present invention. As can be seen, the resulting reaction force F 3  is a sum of the compressive sealing reaction force F 1  and the CPA member closing reaction force F 2 . As is apparent from the graph of the force F 2 , which originates from the engagement of the CPA member  20  with the connector housing  30 , said force F 2  partly compensates in the constantly increasing compressive sealing reaction force F 1  originating from the compression and friction of the flexible sealing element  50  in the last half millimeter of displacement of the CPA member  20 . Hence the resulting reaction force F 3  becomes negative although force F 1  increases. This allows that the CPA member  20  is urged towards its sealed position and no further pushing force must be applied by a user. As is apparent from graph F 3 , the interplay of the single components of the plug connector  10 , namely the CPA member  20 , the connector housing  30  and the flexible sealing element  50  allows to obtain a resulting force F 3  with one maximum value around 0.8 mm of displacement and no further force peaks and negative force values at the end of the displacement. This accordingly allows a proper haptic feedback for a user, wherein he or she is able to unambiguously determine the state of the CPA member  20  movement and its state during closing movement. 
       FIG.  7    shows a cross sectional close-up view of another embodiment of a force feedback configuration with a rigid force feedback element  24  and two flexible force feedback counter elements  34 , when the CPA member  20  is in an open position. As shown, respective contact heads  36  of the two force feedback counter elements  34  are formed by a connector housing  30 . The contact heads  36  are each arranged between the latching protrusions  27  and a respective side of the bulge  26  of the force feedback element  24 , wherein the bulge  26  has a maximum protrusion width W 1 . The two symmetrical flexible force feedback counter elements  34  thus work symmetrically against the central rigid force feedback element  24  such that the rigid force feedback element  24  is loaded symmetrically. 
     In particular,  FIG.  8    shows a cross sectional view of another embodiment of the electrical connector assembly according to the present invention when the first connector member  20 , which is shown as a counter-connector  20  is in an open or unmated position. A second connector member is shown as a plug connector  10 , which is configured to mate with the corresponding counter-connector  20 , which together form a sealed electrical connector assembly  1 . The counter-connector  20  is shown in a disconnected state, whereas it should be understood that it may of course be provided being mated with the plug connector  10 . The plug connector  10  includes a second connector member housing  30 , which is shown as a connector housing  30 , which encloses any further parts of the plug connector  10 , such as electrical components. An electrical cable  12  is connected to the plug connector  10  and provides an electrical connection to further components which are connected to the sealed electrical connector assembly  1 . The plug connector  10  further includes a CPA member. Both, the counter-connector  20  and the CPA member are arranged to be received by the connector housing  30 . In this embodiment, the CPA member, the counter-connector  20  and the connector housing  30  are formed in a circular manner. The counter-connector  20  is able to move along a first or mating direction  100  into a sealed position, whereas the connector housing  30  and its respective parts remain in a fixed position. The counter-connector  20  includes a first connector member sealing wall  22 , which is shown as a counter-connector sealing wall  22  at its top side, which extends essentially along the mating direction  100 . The counter-connector sealing wall  22  is slightly slanted along the mating direction  100 , such that it has a cone-shaped appearance. The slanted counter-connector sealing wall  22  is received by a respective aperture on the bottom side of the connector housing  30 , which has, in this embodiment, a circular appearance. The inner wall of the circular receiving aperture, which forms a second connector member sealing wall  32 , which is shown as a connector housing sealing wall  32  is provided with a flexible sealing element  50  which includes two compressible lips  52 , which are configured such that the slanted counter-connector sealing wall  22  can slide along said compressible lips  52  when the counter-connector  20  is pushed into the sealed position. 
       FIG.  9    schematically shows a cross sectional view of the electrical connector assembly of  FIG.  8    according to the present invention when the counter-connector  20  is in a sealed position. Again, the counter-connector is shown being connected to the plug connector  10  to establish an electrical connection. After the plug connector  10  and the counter-connector have been mated, the counter-connector  20  is brought into the sealed position, which allows the counter-connector  20  to allow a safe electrical connection. As can be seen, the counter-connector  20  has been pushed towards the mating direction  100 . The counter-connector sealing wall  22  has been moved along the compressible lips  52 , which are arranged and compressed in the sealing region  40 , which is the region wherein the watertight seal between the counter-connector sealing wall  22  and the connector housing sealing wall  32  is formed. 
       FIG.  10    shows compressible lips  52  of the flexible sealing element  50  during a displacement of a counter-connector  20  of an embodiment of a sealed electrical connector assembly  1  according to the present invention as shown in  FIGS.  8  and  9   . The progress of movement is depicted in  FIG.  10 A- 10 C , such that the counter-connector  20  moves along the mating direction  100  and travels across the counter-connector mating path distance  28  from  FIG.  10 A- 10 C . The flexible sealing element  50  is fixed to the connector housing  30 . The slanted counter-connector sealing wall  22  decreases in width W 2  along the mating direction  100 , which is illustrated by an angle α in  FIG.  10 C , with respect to the mating direction  100 , which is the vertical direction. The slanted counter-connector sealing wall  22  includes a lead-in chamfer  23 , which is slanted to facilitate a lead-in of the flexible sealing element  50 .  FIG.  10 A  shows the situation before the counter-connector  20  contacts the flexible sealing element  50 .  FIG.  10 B  shows the situation when the lower compressible lip of the compressible lips  52  is in slight contact with the slanted counter-connector sealing wall  22 .  FIG.  10 C  shows the counter-connector  20  in a final and fully sealed position, wherein the flexible sealing element  50  is compressed in the sealing region  40  between the counter-connector sealing wall  22  and connector housing sealing wall  32 . A respective compressive sealing reaction force is maximum in this position. The configuration essentially corresponds to the configuration of the first embodiment of the present invention depicted for instance in  FIGS.  3 A- 3 E  and similar reaction force behavior can be obtained such that no significant force peaks are provided by the engagement between the flexible sealing element  50  and the counter-connector sealing wall  22  when the counter-connector  20  is moved into the sealed position. The overall force level is relatively low, since the compressible lips  52  are accordingly formed to fit the slanted counter-connector sealing wall  22 . The compressible lips are not compressed to the maximum in the beginning of the movement. The main contact pressure is applied at the last third of the counter-connector movement. 
     LISTING OF REFERENCE NUMBERS 
     
         
           1  sealed electrical connector assembly 
           10  second connector member 
           12  cable 
           20  first connector member 
           22  first connector member sealing wall 
           23  lead-in chamfer 
           24  force feedback element 
           26  bulge 
           27  latching protrusion 
           28  first connector member closing path distance 
           30  second connector member housing 
           32  second connector member sealing wall 
           34  force feedback counter-element 
           36  contact head 
           38  contact portion 
           40  sealing region 
           50  flexible sealing element 
           52  compressible lips 
           60  counter-connector 
           100  first direction 
         α angle of the slanted sealing wall 
         W 1  maximum protruding width of the bulge 
         W 2  width of the sealing wall 
         F 1  compressive sealing reaction force 
         F 2  CPA member closing reaction force 
         F 3  resulting reaction force