FR 3122949 A1 20221118 FR 2105082 A 20210514 The present invention relates to an electrical connector comprising: a housing (12) comprising a plug-in portion (22) insertable into the mating electrical connector along a mating direction (D), the plug-in portion (22) having at least one receptacle (26) to receive at least one electrical contact of an electrically conductive terminal, and a compressive member (18) arranged within the housing (12) such that the compressive member (18) can be compressed along the mating direction (D). According to the present invention, a central axis (C3) of the compressive member (18) is essentially aligned with a central axis (C1) of the plug-in portion (22) of the housing (12) in the mating direction (D). Figure for the abstract: Fig. 2 ELECTRICAL CONNECTOR COMPRISING A CONNECTOR POSITION ASSURANCE ELEMENT The present invention relates to an electrical connector, in particular a squib connector, for a safety restraint system of a motor vehicle, comprising a connector position assurance element (CPA) which makes it possible, together with the action of a compressive member, to automatically prevent an incorrect connection with respect to a mating electrical connector. It is known, in particular in the field of electrical connections for the automobile industry, to use connectors comprising compressive members, in which a compressive member is usually one traditional spring of the helical type arranged in the connector makes it possible to push back a mating electrical connector, during an attempt to couple the electrical connector to the mating electrical connector, as long as the force applied on the electrical connector and/or the mating electrical connector is not sufficient to couple them correctly. In such systems, it is known that the compressive member is relaxed in the electrical connector in its delivery position, i.e., before any attempt at connecting it to a mating connector, and compressed in its axial direction during a coupling attempt with the mating electrical connector, the compression of the compressive member then opposing the coupling direction of the mating electrical connectors. Thus, as long as the force exerted to couple the two mating electrical connectors is not sufficient to complete the coupling, i.e., to allow the locking of the two mating electrical connectors with each other, the tension created by the compression of the compressive member makes it possible to push the mating electrical connector back in a direction opposite the coupling direction, thereby avoiding the possibility of an incorrect connection. In the connectors known from the state of the art, the compression of the compression member must therefore be high enough to allow good ejection of the mating electrical connectors if they are not completely locked with each other. In order to obtain the desired functionality, it is known that the compression member uses at least one spring. It is also known from the state of the art to use connector position assurance (CPA) elements making it possible to monitor and ensure proper coupling of an electrical connector to a mating connector. In the automobile industry, it is in particular known to use CPA elements on the one hand to make sure that two mating electrical connectors are correctly coupled and locked, and on the other hand to strengthen the locking of the mating electrical connectors through additional locking, one purpose of which is to avoid unwanted disconnection of the mating electrical connectors for example due to the many impacts and strong vibrations regularly experienced by the connecting elements of motor vehicles. It is known that the safety restraint systems commonly used in motor vehicle seat belts or air bags comprise pyrotechnic devices that can activate the locking of a belt or the inflation of an airbag based on impact or vibration information received by sensors of the vehicle. It is also known that the electrical cables connecting a control unit of a sensor to a corresponding pyrotechnic device, or squib, end in an electrical connector, which is generally connected to a mating electrical connector receptacle, or squib carrier. It is further known that the airbag squib systems of motor vehicles use standardized squib connectors, the standard for which requires a high degree of compactness and therefore small dimensions relative to connectors used for other systems or electric elements of the vehicle. The standard in particular imposes dimensions that are incompatible with the space necessary for the travel of locking springs like those used in the known spring-lock connectors of the state of the art. Document WO 2015/088636 A1 in particular discloses a self-rejecting automotive harness connector comprising one helical compression spring arranged in the housing of the connector between a cover and a connector position assurance (CPA) element. The arrangement of the helical compression spring as known from WO 2015/088636 A1, however, does not allow distributing the compressive force uniformly with respect to the housing. Moreover, an involuntary contact between the helical compression spring and the electrically conductive terminal is not well prevented. The design according to WO 2015/088636 A1 also requires that the helical compression spring comprises a sufficient amount of spires for sustaining the mechanical stress resulting from the mating operations. Thereby, the helical compression spring as known from WO 2015/088636 A1 has to be provided with a minimum length, which does not allow for further size reduction of the housing. One aim of the present invention is therefore to improve the squib electrical connectors in order to make them more resistant and more reliable than the connectors known from the prior art. The aim of the invention is achieved by means of an electrical connector, in particular a squib connector for a safety restraint system of a motor vehicle, for connecting with a mating electrical connector in a mating direction, said electrical connector comprising: a housing, the housing comprising a plug-in portion insertable into the mating electrical connector along the mating direction, the plug-in portion having at least one receptacle to receive at least one electrical contact of an electrically conductive terminal, and a compressive member arranged within the housing such that the compressive member can be compressed along the mating direction, and a connector position assurance element (CPA) slidable from an unlocked position to a locked position along the mating direction, said locked position of the CPA allowing the electrical connector to be locked to the mating connector when the electrical connector is connected to the mating connector. According to the present invention, a central axis of the compressive member is essentially aligned with a central axis of the plug-in portion of the housing in the mating direction. The alignment of the central axis of the compressive member with the central axis of the plug-in portion of the housing in the mating direction allows improving the force distribution applied on the housing during the mating operation. Indeed, during the compression of the compressive member, taking place along the mating direction, the specific arrangement of the compressive member within the electrical connector according to the invention homogeneously distributes the applied forces with respect to the plug-in portion of the housing. A uniform strain is thus applied on the plug-in portion of the housing, in contrast with the electrical connector of the state of the art, wherein the central axis of the compression spring is not aligned with a central axis of the plug-in portion of the housing. Thereby, the electrical connector according to the present invention is rendered more stable, especially during mating operations. Hence a more resistant and more reliable electrical connector than the connectors known from the prior art is provided. The electrical connector can be further improved according to various advantageous embodiments. According to one embodiment, the compressive member can be configured to exert a reaction force along its central axis. Hence, the compressive member can be deformed along a direction parallel to the mating direction. According to one embodiment, the CPA can comprise a head from which extends at least one latching arm, said at least one latching arm being configured to prevent relative movement between the CPA and the housing in the locked position, the compressive member being partially arranged on the head of the CPA. As the compressive member is partially arranged on the head of the CPA, the compression member can directly apply a force to the CPA. Under the action of a force applied to the CPA by the compressive member, the CPA can be slid in the mating direction. In particular, the CPA can be slid from the unlocked position to the locked position, thereby providing the function of a CPA to the electrical connector. According to one embodiment, the compressive member can be partially arranged in a recess or around a protuberance of the head of the CPA. It allows providing a better retention of the compressive member to the CPA. A good retention of the compression member is particularly needed for automotive applications, wherein the electrical connector can face chocks and vibrations. According to one embodiment, the head of the CPA can be configured to integrally cover the at least one receptacle for receiving at least one electrical contact of an electrically conductive terminal. The CPA is made of an electrically insulating material, in particular of plastic. The CPA according to the present invention is thus arranged so as to provide an electrically insulating barrier between the compressive member and the electrical contacts of the electrically conductive terminals. Hence, the risk of contact between the electrical contacts and the compressive member can be prevented by means of the CPA design and arrangement. As a result, the risk of short-circuit between the electrical contacts and the compressive member can be reduced. Moreover, as the CPA integrally covers the at least one receptacle, the CPA also acts as a lid for the receptacle, thereby preventing any direct access to the receptacle and the electrical contact arranged therein. According to one embodiment, the housing can further comprise a portion for receiving at least one electrically conductive terminal extending from the at least one electrical contact. The housing is thus adapted to comprise the electrical contacts as well as the electrically conductive terminals from which the electrical contacts extend. According to one embodiment, the electrical connector can further comprise a cover that can be attached to the housing, said cover being configured: to at least enclose the compressive member, and to partially enclose the CPA. Hence, a loss of the compressive member is prevented thanks to the cover. The CPA is at least partially enclosed by the cover, so that a loss of the CPA can also be prevented. However, a portion of the CPA can protrude from the enclosure formed by the cover and the housing, as so to provide a handling portion and/or a visual indicator of the CPA position to an operator. According to one embodiment, the compressive member can be partially arranged in a recess or around a protuberance of the cover. The compressive member can thus be compressed by means of a force applied on the cover. It also allows providing a better retention of the compressive member to the cover. A good retention of the compression member is particularly needed for automotive applications, wherein the electrical connector can face chocks and vibrations. According to one embodiment, the compressive member can be a cylindrical compression spring, a conical compression spring, a multi-waves compression spring or an elastomer spring. Cylindrical compression springs are widely available and cost-effective. Conical compression springs provide a compact and space-saving compressive member as the spring coils fit into each other under compression. Multi-waves compression springs provide a further compact and space-saving compressive member. In particular, the height of such compressive member can be reduced, in comparison with a cylindrical or conical compression spring, for the same compression force Elastomer springs allow providing an electrically insulating compressive member. According to one embodiment, the electrical connector can comprise at least two compressive members arranged such that the respective central axis of each compressive member is essentially aligned with the central axis of the plug-in portion of the housing in the mating direction. Hence, an alternative arrangement can be obtained, providing an even more robust and thus reliable electrical connector because of the plurality of compressive members. The invention will be explained more detail hereinafter using advantageous embodiments and based on the following accompanying figures, in which: represents an exploded view of an electrical connector according to a first embodiment of the present invention and a mating electrical connector. represents a cross-section of a side view of the electrical connector according to the first embodiment of the present invention. represents a partial three dimensional view of an electrical connector according to the first embodiment of the present invention. represents a top view of the electrical connector according to the first embodiment of the present invention. represents a cross-section of a side view of an electrical connector according to a second embodiment of the present invention. The accompanying drawings are merely for the purpose of illustrating the preferred and alternative examples of how the invention can be made and used, and are not to be construed as limiting the invention to only the illustrated and described embodiments. Furthermore, several aspects of the embodiments may form - individually or in different combinations – solutions according to the present invention. The following described embodiments thus can be considered either alone or in an arbitrary combination thereof. Further features and advantages will become apparent from the following more particular description of the various embodiments of the invention, as illustrated in the accompanying drawings. represents an exploded view of an electrical connector 10 according to a first embodiment of the present invention and a mating electrical connector 100. The electrical connector 10 is configured to be mated with the mating electrical connector 100 along a mating direction D. The electrical connector 10 corresponds to the assembly of several elements: a housing 12, at least one electrically conductive terminal 14, a connector position assurance element 16 (referred as “CPA 16” in the following), a compressive member 18 and a cover 20. The housing 12 of the electrical connector 10 comprises two main portions 22, 24: a plug-in portion 22 and a receiving portion 24. The housing 12 is integrally formed, in particular by injecting molding. The plug-in portion 22 is the portion of the housing 12 insertable into the mating electrical connector 100 along the mating direction D. The plug-in portion 22 is thus of suitable geometry for being plugged in the mating electrical connector 100. In the example illustrated by , the plug-in portion 22 is substantially cylindrical with a diameter L1 (the diameter L1 is visible in ). The plug-in portion 22 has a central axis C1. The central axis C1 passes through the center of gravity of the plug-in portion 22 (not visible in ). The central axis C1 is parallel to the mating direction D. In the case wherein the plug-in portion 22 is substantially cylindrical, as illustrated in , the central axis C1 also corresponds to the central longitudinal axis and to the axis of revolution of the plug-in portion 22. All these axis, represented by C1 in , pass through the center of gravity of the plug-in portion 22 (not visible in ). Moreover, all these axis, represented by C1 in , are parallel to the mating direction D. The plug-in portion 22 comprises two receptacles 26 configured for receiving electrical contacts 28 of the electrically conductive terminals 14. The number of receptacles 26 is adapted to the number of electrical contacts 28. The receptacles 26 are of suitable geometry for accommodating the electrical contacts 28. In particular, each receptacle 26 respectively forms a tunnel 30 within the plug-in portion 22. A central longitudinal axis C2 of each tunnel 30 (i.e. of each receptacle 26) is parallel to the central axis C1 of the plug-in portion 22. The tunnels 30 are hollow cylindrical openings 30 with complementary dimensions (in particular in diameter and length) to the electrical contacts 28. Provided at an external circumference 32 of the plug-in portion 22, said plug-in portion 22 comprises two locking lances 34 (only one is visible in the view of ), which can be deflected inwardly, i.e. towards an inside of the plug-in portion 22 in a respective deflection space (not visible in the view of , but shown in by means of the reference 33) in order to allow the insertion of the plug-in portion 22 in the mating electrical connector 100. As mentioned above, the housing 12 further comprises a receiving portion 24. In the example illustrated by , the receiving portion 24 is of substantially parallelepipedal geometry. In the example illustrated by , the receiving portion 14 comprises a first region 36 configured for receiving the CPA 16 slidingly therein and a second region 38 configured for receiving the electrically conductive terminals 14 and a ferrite bead 40. In a variant (not represented), the electrically conductive terminals 14 are not provided with a ferrite bead 40. The electrically conductive terminals 14 are terminated by the electrical contacts 28. The electrically conductive terminals 14 pass through the ferrite bead 40. In the ferrite bead 40, as shown in , the electrically conductive terminals 14 are crimped to electrical conductors 42. The electrical conductors 42 exit the receiving portion 24 through cables 44 passing via openings 46 of the receiving portion 24.In the example illustrated in , the electrically conductive terminals 14 are bent at three locations. In variants (not represented), the electrically conductive terminals 14 can be bent at one location only, or at two locations only, or, at four or more locations. As shown in , a first bent of the electrically conductive terminals 14 (only visible in , see section of the electrically conductive terminals 14 indicated by reference 14A) forms a right angle A1 with respect to the electrical conductors 42. The first bent (i.e. the right angle A1) is located at a junction 37 between the first region 36 and the second region 38. A second bent of the electrically conductive terminals 14 forms a right angle A2 between two sections 14B, 14C of the electrically conductive terminal 14 in the first region 36, as shown in . A third bent of the electrically conductive terminals 14 forms a right angle A3 between the section 14C of the electrically conductive terminal 14 and the electrical contact 28 at a junction between the first region 36 and the plug-in portion 22, as shown in . Hence, the second bent forming the right angle A2 is disposed between the first bent (A1) and the third bent (A3). The electrically conductive terminals 14 thus comprises three bent sections 14A, 14B and 14C. The first section 14A is perpendicular to the second section 14B, that is itself perpendicular to the third section 14C. The first section 14A is parallel to the third section 14C. As further explained thereafter, the bent design of the electrically conductive terminals 14 allow providing shorter electrical contacts 28. Hence, raw material can be saved for manufacturing the electrically conductive terminals 14 used within the electrical connector 10 according to the present invention. The plug-in portion 22 extends substantially perpendicularly from the receiving portion 24 at the first region 36. The receptacles 28 of the plug-in portion 22 thus correspond to tunnels 30 leading to the first region 36 of the receiving portion 24. Hence, the electrical contacts 28 can be accommodated into the receptacles 38 of the plug-in portion 22 via the first region 36 of the receiving portion 24 along the mating direction D, as shown by the exploded view of . The CPA 16 is also configured to be accommodated in the plug-in portion 22 via the first region 36 of the receiving portion 24 along the mating direction D. To this end, the plug-in portion 22 comprises longitudinal openings 48, 50 (only visible in ), extending along a direction parallel to the mating direction D, for receiving some portions (detailed thereafter) of the CPA 16 in the mating direction D. The CPA 16 is slidable from an unlocked position to a locked position along the mating direction D. The locked position of the CPA 16 allows the electrical connector 10 to be locked to the mating connector 100 when the connectors 10, 100 are properly mated together. The CPA 16 according to the present invention comprises a substantially flat head 52 from which extends perpendicularly two latching arms 54 along the mating direction D. Each latching arm 54 ends with a hook 56. The latching arms 54 and their corresponding hooks 56 are configured to prevent relative movement between the CPA 16 and the housing 12 in the locked position. The latching arms 54 are configured to be received in the longitudinal openings 48 of the plug-in portion 22 (visible in ). As shown in , further tabs 58 extend perpendicularly from the head 52 of the CPA 16 in the same direction as the latching arms 54. The tabs 58 are configured to be received in the longitudinal openings 50 of the plug-in portion 22 (visible in ). The tabs 58 provide further mechanical support, and thus stability, to the CPA 16 in the locked position. As mentioned above, the head 52 of the CPA 16 is essentially flat. It allows providing a flat surface 61A onto which the compressive member 18 can be compressed, thereby facilitating a homogeneous distribution of compressive forces thanks to the flat geometry of the CPA head 52. Hence, the CPA 16 is further rendered more robust and stable. In the first embodiment, the head 52 of the CPA 16 comprises a circular recess 60 on the surface 61A (or side 61A) opposite to the side 61B from which extend the latching arms 54 and the tabs 58. The circular recess 60 has a diameter L2. The diameter L2 of the circular recess 60 is adapted to a diameter L3 of the compressive member 18. In a variant, not illustrated, instead of a circular recess 60, the head 52 is provided with a protuberance having an essentially cylindrical or conical shape having a base of diameter L2. When the compressive member 18 is a cylindrical compression spring 62, like in the first embodiment shown in , the diameter L3 of the compressive member 18 corresponds to the diameter L3 of each coil. It is noted that the diameter of each coils of a cylindrical compression spring is identical to each other. When the compressive member 18 is a conical compression spring, like in a second embodiment of the present invention (shown in ), the diameter L3 corresponds to the diameter of the greater coil of the conical compression spring. This aspect is further described thereafter in reference to . The circular recess 60 (or protuberance) of the CPA 16 provides a retention means for holding and stabilizing the compressive member 18. Indeed, the circular recess 60 forms a circular border that can enclose the portion of the compressive member 18 located in the circular recess 60. The head 52 of the CPA 16 further comprises two opposite end-portions 64, distinct from the circular recess 60, that provides handling portions for grasping the CPA 16 and/or a visual indicator of the CPA 16 position to an operator. As shown in , the two opposite end-portions 64 are formed by the surfaces 61A, 61B of the head 52 of the CPA 16. The compressive member 18 has a central axis C3. As indicated above, in the first embodiment shown in , the compressive member 18 is a cylindrical compression spring 62. The central axis C3 of the cylindrical compression spring 62 corresponds to the central longitudinal axis of the cylindrical compression spring 62. Under compression, in particular in the mating direction D, the compression forces applied to the compression member 18 act along the central axis C3. Thus, the central axis C3 of the compression member 18 also corresponds to a compression axis of the compression member 18. The central axis C3 of the compression member 18 is parallel to the mating direction D. The electrical connector 10 further comprises the cover 20. The cover 20 has a shape substantially complementary to the housing 12 and can engage the housing 12 by a snap-fit connection. Thereby, a rigid and unitary connector 10 enclosing the electrically conductive terminals 14 is obtained. The electrical contacts 28, the electrically conductive terminals 14 and the ferrite bead 40 are thus enclosed within the electrical connector 10 by means of the cover 20. The cover 20 comprises two openings 66 (only one is visible in ) having a U-shape and provided on a lateral wall 68 of the cover 20. The lateral wall 68 partially extends perpendicularly from a main face 69 of the cover 20. The openings 66 respectively provide passages 70 for the end-portions 64 of the head 52 of the CPA 16. Hence, the end-portions 64 of the CPA 16 remains accessible to an operator, even when the cover 20 is snap-fit to the housing 12. The main face 69 is substantially flat. As shown in , a first surface 69A of the main face 69 is exposed to the external environment. A second surface 69B, opposite to the first surface 69A, corresponds to the inner surface of the cover 20, i.e. the surface 69B that is positioned within the electrical connector 10 and that is, thus, not exposed to the external environment. Still in reference with , the surface 69B of the cover 20 is provided with a protuberance 74 having an essentially cylindrical shape. The free end 76 of the protuberance 74 can be a chamfered end. The protuberance 74 has a diameter L4 adapted to the diameter L3 of the compressive member 18. Hence, the compressive member 18 can be inserted around the protuberance 74, as shown in , and retain thereto. In particular, the compressive member 18 can be retained to the protuberance 74 by friction fit i.e. by interference fit. In a variant, the protuberance 74 can be of a substantially conical shape with a base having the diameter L4. As shown in . a wall 78 extends perpendicularly from the surface 69B of the cover 20. The wall 78 has a height H2, slightly smaller than a height H1 of the first region 36 at the junction 37 (H1 is indicated in ). The difference H3 (shown in ) between the heights H1 and H2 is adapted to pass the electrically conductive terminals 14, in particular at the right angle A2. As shown in , and in comparison with wherein the cover 20 is not represented, the wall 78 of the cover 20 allows providing an electrically insulating barrier between the compressive member 18 and the electrically conductive terminals 14, in particular with the section 14B of each electrically conductive terminal 14. Thereby, the risk of short-circuit between the compressive member 18 and the electrically conductive terminals 14 can be reduced. As shown in , representing an assembled state of the electrical connector 10, the compressive member 18 is held between the CPA 16 and the cover 20. More precisely, the compressive member 18 is held, for instance by friction fit and by press fit, between the circular recess 60 of the CPA 16 and the protuberance 74 of the cover 20. According to the present invention, the compressive member 18 is arranged within the first region 36 of the receiving portion 24 of the housing 12 such that the central axis C3 of the compressive member 18 is essentially aligned with a central axis C1 of the plug-in portion 22. The alignment of the axis C1, C3 is further illustrated by the top view of . The aligned axis C1, C3 are parallel to the mating direction D. The axis C1, C3 passes through the center of the circular recess 60 of the head 52 of the CPA 16. The alignment of the axis C1, C3 allows improving the force distribution applied on the housing 12 during the mating operation along the mating direction D. Indeed, during the compression of the compressive member 18, which exerts a reaction force along its central axis C3, parallel to the mating direction D, the specific arrangement of the compressive member 18 within the electrical connector 10 according to the invention homogeneously distributes the applied forces with respect to the plug-in portion 22 of the housing 12. A uniform strain is thus applied on the plug-in portion 22 of the housing 12. Thereby, the electrical connector 10 according to the present invention is rendered more stable, especially during mating operations. Furthermore, the design and the arrangement of the CPA 16 according to the present invention helps preventing contact (and thus short circuits) between the electrically conductive terminals 14 and the compressive member 18. This is because the essentially flat head 52 of the CPA 16 is dimensioned for covering the plug-in portion 22, so as to integrally cover the receptacles 26 wherein the electrical contacts 28 are inserted thereinto. In particular, the essentially flat head 52 of the CPA 16 has a width H4 substantially equivalent to the diameter L1 of the plug-in portion 22. As shown in and , the head 52 of the CPA 16 provides an electrically insulating barrier between the compressive member 18 and the electrical contacts 28, as well as with the section 14C of each electrically conductive terminal 14. Indeed, as shown in , the section 14C of the electrically conductive terminal 14 is physically separate from the compressive member 18 by means of the presence of the housing 12, the wall 78 of the cover 20 and the head 52 of the CPA 16. The section 14B is in fact covered by the wall 78 of the cover 20 while the section 14C is covered by the head 52 of the CPA 16. The cover 20 and the CPA 16 are made of plastic and are therefore electrically insulating. Further, as the dimension of the head 52 of the CPA 16 according to the present invention allows providing a CPA 16 with a large surface 61A, i.e. essentially as large as the diameter L1 of the plug-in portion 22, a compressive member 18 with a larger diameter L3 than in the state of the art can be used. Hence, it allows using a compressive member 18, larger than the ones used in the state of art, and with a smaller height (i.e. the length along the compressive axis) than the ones used in the state of art, for an equivalent compressive force. As a result, because the height of the compressive member 18 can be reduced, the height H1 of the receiving portion 24 can be reduced, thereby advantageously providing a more compact housing 12. Moreover, the multi-bent sections 14A, 14B, 14C at right angles A1, A2, A3 allow providing electrically conductive terminals 14 with shorter electrical contacts 28 than in the state of the art. It therefore allows using less raw material for the electrically conductive terminals 14 and their electrical contacts 28. In a second embodiment, as illustrated in , the compressive member 18 can be a conical compression spring 80. Elements with the same reference numeral already described and illustrated in Figures 1 to 4 will not be described in detail again but reference is made to their description above. The conical compression spring 80 has one first free-end 82 and a second free-end 84. The coil at the first free-end 82 of the conical compression spring 80 has a diameter L5. The coil at the second free-end 84 of the conical compression spring 80 has a diameter L6. The diameter L6 is greater than the diameter L5 because the compression spring 80 is conical. The first free-end 82 is arranged around the protuberance 74 and thus hold to the cover 20. In particular, the first free-end 82 can be hold to the cover 20 by friction fit. The second free-end 84 is arranged within the circular recess 60 of the head 52 of the CPA 16. The diameter of the successive coils of the conical compression spring 80 thus increases in the mating direction D. In a variant (not represented), the diameter of the successive coils of the conical compression spring 80 can increase in a direction opposite to the mating direction D. The conical compression spring 80 provide a compact and space-saving compressive member 18 as the spring coils fit into each other under compression along the mating direction D. In another embodiment, not illustrated, the compressive member 18 is a multi-waves compression spring or an elastomer spring. In another embodiment, not illustrated, the housing 12 comprises at least two compressive members 18 arranged such that the respective central axis C3 of each compressive member 18 is essentially aligned with the central axis C1 of the plug-in portion 22 of the housing 12 in the mating direction D. Although the embodiments have been described in relation to particular examples, the invention is not limited and numerous alterations to the disclosed embodiments can be made without departing from the scope of this invention. The various embodiments and examples include individual features can be freely combined with each other to obtain further embodiments or examples according to the invention. LIST OF REFERENCE SIGNS 10: electrical connector according to a first embodiment of the present invention 100: mating electrical connector 12: housing 14: electrically conductive terminal 14A, 14B, 14C: sections of the electrically conductive terminal 14 16: connector position assurance element 16 (referred as CPA 16) 18: compressive member 20: cover 22: plug-in portion 24: receiving portion 26: receptacle 28: electrical contacts of the electrically conductive terminals 14 30: tunnel 32: external circumference of the plug-in portion 22 33: deflection space 34: locking lances 36: first region 37: junction between first region and second region 38: second region 40: ferrite bead 42: electrical conductors 44: cables 46: openings of the receiving portion 24 48, 50: longitudinal openings the plug-in portion 22 52: head of the CPA 16 54: latching arm 56: hook 58: tab 60: circular recess 61A, 61B: opposite surfaces of the CPA 62: cylindrical compression spring 64: end-portion 66: opening 68: lateral wall of the cover 20 69: main face 69A, 69B: opposite surfaces 70: passage 74: protuberance 76: free end 78: wall 80: conical compression spring 82, 84: free end of the conical compression spring A1, A2, A3: right angle C1: central axis of the plug-in portion 22 C2: central axis of the tunnel 30 C3: central axis of the compressive member 18 D: mating direction H1, H2: height H3: height difference H4: width of the CPA 16 L1, L2, L3, L4, L5, L6: diameter X, Y, Z: Cartesian coordinates Electrical connector, in particular a squib connector for a safety restraint system of a motor vehicle, for connecting with a mating electrical connector in a mating direction, said electrical connector comprising: a housing (12), the housing (12) comprising a plug-in portion (22) insertable into the mating electrical connector along the mating direction (D), the plug-in portion (22) having at least one receptacle (26) to receive at least one electrical contact of an electrically conductive terminal, and a compressive member (18) arranged within the housing (12) such that the compressive member (18) can be compressed along the mating direction (D), and a connector position assurance element (CPA 16) slidable from an unlocked position to a locked position along the mating direction (D), said locked position of the CPA (16) allowing the electrical connector to be locked to the mating connector when the electrical connector is connected to the mating connector, characterized in that a central axis (C3) of the compressive member (18) is essentially aligned with a central axis (C1) of the plug-in portion (22) of the housing (12) in the mating direction (D). The electrical connector according to claim 1, wherein the compressive member (18) is configured to exert a reaction force along its central axis (C3). The electrical connector according to claim 1 or 2, wherein the CPA (16) comprises a head (52) from which extends at least one latching arm (54), said at least one latching arm (54) being configured to prevent relative movement between the CPA (16) and the housing (12) in the locked position, the compressive member (18) being partially arranged on the head (52) of the CPA (16). The electrical connector according to claim 3, wherein the compressive member (18) is partially arranged in a recess (60) or around a protuberance of the head (52) of the CPA (16). The electrical connector according one of the preceding claims, wherein the head (52) of the CPA (16) is configured to integrally cover the at least one receptacle (26) for receiving at least one electrical contact of an electrically conductive terminal. The electrical connector according to one of the preceding claims, wherein the housing (12) further comprises a portion (24) for receiving at least one electrically conductive terminal extending from the at least one electrical contact. The electrical connector according to one of the preceding claims, further comprising a cover (20) that can be attached to the housing (12), said cover (20) being configured: to at least enclose the compressive member (18), and to partially enclose the CPA (16). The electrical connector according to claim 7, wherein the compressive member (18) is partially arranged in a recess or around a protuberance (74) of the cover (20). The electrical connector according to one of the preceding claims, wherein the compressive member (18) is a cylindrical compression spring (62), a conical compression spring (80), a multi-waves compression spring or an elastomer spring. The electrical connector according to one of the preceding claims, comprising at least two compressive members (18) arranged such that the respective central axis (C3) of each compressive member (18) is essentially aligned with the central axis (C1) of the plug-in portion (22) of the housing (12) in the mating direction (D).