Patent Publication Number: US-7708582-B2

Title: Electrical connector

Description:
The present invention has for its object an electrical connector. 
   The electrical connectors are at present utilized for various applications, for example for the connection of two electronic devices. For certain applications, the electrical connectors comprise interfacial sealing covers, disposed at the level of electrical contacts, which are adapted to ensure sealing between the plug-in portions of the connector. These interfacial sealing covers are effective only when sufficiently compressed. Their compression however requires the application of a substantial force during connection, which involves the use of special tools. 
   Moreover, the intervals of production tolerance can give rise to play between the plug-in parts, which can impede the locking and/or the connection of the plug-in parts as well as the interfacial sealing. 
   The present invention has for its object to provide an electrical connector which avoids at least certain of the mentioned drawbacks, which permits, despite tolerances, guaranteeing the interfacial sealing of the coupling, the connection and the locking, and which does not require a tool to carry out the connection and disconnection operations. 
   To this end, the invention has for its object an electrical connector comprising a first plug-in or base part and a second plug-in or plug, adapted to be electrically connected by relative translation of the plug-in parts along a connection axis, characterized in that 
   said first plug-in part comprises first guide means adapted to coact with second guide means of a connection element of the second plug-in part, to permit relative displacement of the connection element with respect to the first plug-in part, between a release position, in which said connection element is free relative to said first plug-in part, and a locking position, in which said connection element is secured to said first plug-in part along the connection axis, 
   said second plug-in part comprising a housing comprising a third guide means adapted to coact with the connection element to permit relative displacement of the connection element with respect to the housing along the connection axis, the second plug-in part comprising resilient means disposed between said housing and said connection element, and adapted, when said connection element is in locking position, to provide relative movement of the housing with respect to the connection element such that the housing moves in the direction of the first plug-in part along the connection axis. 
   Preferably, said housing has an overall parallelepipedal rectangular shape, said connection element having substantially a U shape, the central portion of the connection element extending transversely along a so-called upper wall of said housing, the two lateral portions of the connection element extending transversely along two opposite so-called lateral walls of the housing. 
   According to one embodiment of the invention, said first plug-in portion has an overall rectangular parallelepipedal shape, the second guide means including, on each lateral portion of the connection element, a projection which projects in the direction of the other lateral portion, the first guide means including, on two opposite so-called lateral walls of the first plug-in part, a recess defining on one of its edges a guide ramp, each projection being adapted to engage in the corresponding recess and to move into the recess along the guide ramp. 
   Preferably, the recess defines, in cooperation with an end of said corresponding guide ramp, a recess, the projection being held in position in said recess in the locked position. 
   Preferably, the second guide means include, on each lateral portion of the connection element, two projections which project in the direction of the other lateral portion, the two projections being aligned along an axis substantially perpendicular to the connection axis, the first guide means including, on two so-called lateral opposed walls of the first plug-in portion, two recesses, each recess defining on one of its edges a guide ramp, each projection being adapted to engage in the corresponding recess, and to move into the recess along the guide ramp. 
   According to one embodiment of the invention, the third guide means include a guide ramp projecting from the so-called upper wall of the housing, an edge of said central portion bearing against guide ramp, said central portion being adapted to move along said guide ramp. 
   Preferably, said guide ramp permits relative movement of the connection element with respect to the housing along the connection axis to permit the locking of the connection element on said first plug-in portion before the connection operation between the first plug-in part and the second plug-in part has concluded, which permits decreasing the connection force. 
   Preferably, the third guide means include, on each so-called lateral wall, a guide ramp, a corner of each lateral portion being in bearing relation against the corresponding guide ramp, each lateral portion being adapted to move along said corresponding guide ramp. 
   According to an embodiment of the invention, each lateral portion of the connection element comprises a guide groove extending along an axis substantially perpendicular to the connection axis, each so-called lateral wall of the housing comprising a flange adapted to engage in said corresponding guide groove with play along the connection axis, a blade forming a spring being disposed in each of said guide grooves and urging relative movement of the connection element with respect to the housing along the connection axis. 
   Preferably, after locking of the connection element on said first plug-in portion, the blades forming a spring ensure relative movement between the housing and the first plug-in portion to permit taking up the play along the connection axis. 
   According to an embodiment of the invention, each lateral portion comprises a recess adapted to receive one end of a helicoidal spring, the other end of said helicoidal spring being engaged in a recess in the corresponding so-called lateral wall, said spring being disposed along an axis substantially perpendicular to the connection axis to ensure relative movement along said axis substantially perpendicular to the connection axis of the connection element and of the housing, so as to move and hold the projection in the recess to ensure locking. 

   
     The invention will be better understood, and other objects, details, characteristics and advantages of the latter will become more clearly apparently, in the course of the detailed explanatory description which follows, of an embodiment of the invention given by way of purely illustrative and not limiting example, with reference to the accompanying schematic drawings. 
     In these drawings: 
       FIG. 1  is a schematic cross-sectional view, simplified and in perspective, of an electrical connector comprising a plug and a base according to an embodiment of the invention; 
       FIG. 2  is a schematic view, simplified and in perspective, of the housing and electrical contacts of the plug of  FIG. 1 ; 
       FIG. 3A  is a fragmentary schematic view, simplified, and in perspective, showing a lateral portion of the stirrup and of the guide ramps of the plug of  FIG. 1 ; 
       FIG. 3B  is a view similar to  FIG. 3A  showing a guide groove of the stirrup; 
       FIG. 4  is a simplified side schematic view of the plug and base of  FIG. 1  in the disconnected position; 
       FIG. 5  is a view similar to  FIG. 4  showing an intermediate position in the connection operation of the plug and the base; and 
       FIG. 6  is a view similar to  FIG. 4  showing the plug and the base in connected position. 
   

   With reference to  FIG. 1 , there will be seen a connector  1  comprising a first plug-in portion, called base  2 , and a second plug-in portion, called plug  3 . Base  2  is for example connected to an electronic device (not shown) integrated into an aircraft structure (not shown). The base  2  is fixed relative to the structure. The plug  3  is for example connected to a connector adapted to connect two pieces of electronic equipment (not shown). The base  2  and the plug  3  are adapted to be connected to each other by translation of the plug  3  relative to the base  2  in the connection direction X. 
   The base  2  comprises a housing  5  made for example of molded plastic or metal. The housing  5  has a generally rectangular parallelepipedal shape and comprises an upper wall  6 , a lower wall  7  and two side walls  8 . The front surface  10  of the housing  5  is open to permit access to the electrical contacts  11  distributed in four rows in the embodiment shown, the number of these rows not being limiting. 
   The electrical contacts  11  project from an interfacial sealing cover (not shown in  FIG. 1 ) disposed in a transverse plane of the housing  5 . The interfacial sealing cover is made of a sealing and deformable material, for example silicone. Each electrical contact  11  is surrounded by a projection (not shown in  FIG. 1 ) of the interfacial sealing cover, substantially in the form of a chimney, projecting toward the front surface  10 . In a manner known per se, the electrical contacts  11  are connected at their rear portion to a cable (not shown) or to an electrical circuit. 
   Each side wall  8  of the housing  5  comprises a recess  13 , of which a lateral edge  14  is disposed in the plane of the front surface  10 , and whose upper edge defines a guide ramp  16 . One end  16   a  of the ramp  16  is disposed in the plane of the front surface  10 . The ramp  16  is inclined downwardly, in a direction opposite the front surface  10 , at an angle α relative to the axes X. For example, the angle α is substantially equal to 45°. The opposite end  16   b  of the ramp  16  opens into a recess  20  adapted to receive a lug of a stirrup, such as will be described in detail later on. 
   Each side wall  8  of the housing  5  comprises a second recess  23 , similar to recess  13 . The side edge  24  of the recess  23 , disposed in the plane of the front surface  10 , is offset along an axis Z, perpendicular to the axis X and parallel to the plane of the front surface  10 , relative to the side edge  14 . The upper edge  25  of the recess  23  defines a ramp  26  similar to ramp  16 . The ramp  26  opens into a recess  30  adapted to receive a second lug of the stirrup. 
   Referring to  FIGS. 1 ,  2 ,  3 A and  3 B, plug  3  comprises a housing  33  made for example of molded plastic or metal. The housing  33  has a generally rectangular parallelepipedal shape whose cross-section is adapted to the cross-section  5  of the base  2 , such that the housing  33  of the plug  3  can be encased in the housing  5  of the base  2 . The housing  33  comprises an upper wall  34 , a lower wall  35  and two side walls  36 . 
   The front surface  38  ( FIG. 2 ) of the housing  33  is open to permit access to the electrical contacts  39  adapted to coact with the electrical contacts  11 . The electrical contacts  39  are disposed in recesses  40  of substantially conical shape of a cover  41  disposed in a transverse plane of the housing  33 . The cover  41  is for example made of plastic. In a manner known per se, the electrical contacts  39  are connected at their rear portion to a cable or to an electrical circuit (not shown). 
   The plug  3  comprises a connection element, called stirrup  43  ( FIG. 1 ). The stirrup  43  has overall a U shape. The central portion  44  of the U is disposed substantially transversely along the upper wall  34  of the housing  33 . The side portions  45  of the U extend transversely along side walls  36  of the housing  33 . 
   Each portion  45  comprises two lugs  46  and  47  ( FIGS. 3A and 3B ), projecting toward the other portion  45 , adapted to engage in recesses  20 ,  30 , respectively, of the corresponding side wall  8 . For purposes of clarity, only one portion  45  has been shown in  FIGS. 3A and 3B . 
   Each portion  45  comprises a guide rail  51  disposed substantially along the axis Z. A flange  52  of the housing  33 , projecting radially in a transverse plane of the housing  33 , is inserted in the guide rail  51  with play, such that the connection between the guide rail  51  and the flange  52  permits displacement along the axis X of the stirrup  43  relative to the housing  33 . A blade  53  of substantially parabolic shape forming a spring, which is for example made of metal, is disposed in the guide rail  51 . The end  53   a  of the blade  53  is fixed to a wall of the guide rail  51 . The end  53   b  of the blade  53  is disposed in a substantially parallel manner to the wall of the guide rail  51  and is adapted to slide relative to the wall of the guide rail. The central portion of the blade  53  bears against the rear surface  54  of the flange  52 . The shape of the blades  53  permits raising the stirrup  43 , as will be described in detail later. 
   The rear edge  55  of the central portion  44  of the stirrup  43  bears along a guide ramp  57  of the forward surface  58  of the flange  52  and is adapted to move along the guide ramp  57  during relative movement of the stirrup  43  with respect to the housing  33 . The guide ramp  57  is inclined at an angle β ( FIG. 2 ) relative to the axis Z, such that, when the stirrup  43  carries out a movement of the axis Z in a direction opposite to the housing  33 , the stirrup  43  will move simultaneously along the axis X in a direction opposite the forward surface  38  of the housing  33 . 
   A lower corner  60  of the rear edge  50  of each portion  45  bears against a guide ramp  61  of the forward surface  58  of the flange  52  and is adapted to move along the guide ramp  61  during relative movement of the stirrup  43  with respect to the housing  33 . The ramp  61  is inclined at the angle β relative to the axis Z. 
   One end of a helicoidal spring  62  is disposed in a recess  63  for each side wall  36  of the housing  33 , the opposite end of the spring  62  being disposed in a recess  64  of the portion  45  corresponding to the stirrup  43 . The spring  63  turns to space the stirrup  43  from the housing  33  along the axis Z. 
   There will now be described a connection operation of the base  2  and the plug  3  according to the embodiment. 
   In the release position, which is to say when the lugs  46 ,  47  are not engaged in the ramps  16 ,  26 , the return springs  62  press the stirrup  43  along the axis Z in a direction opposite to the housing  33  and the blades  53  press the stirrup  43  along the axis X in a direction opposite the front surface  38  of the housing  33 . The stirrup  43  is in the upper position, which is to say that it bears against the upper portions of the ramps  57 ,  61 . 
   When, leaving this position, a user places the front surface  38  of the housing  33  of the plug  3  in line with the front surface  10  of the housing  5  of the base  2 , such that the lugs  46 ,  47  will be located at the level of the ends  16   a ,  26   a  of the ramps  16 ,  26 , the distance d 1  ( FIG. 4 ) between the upper wall  6  of the housing  5  of the base  2  and the portion  44  of the stirrup  43  is at a maximum, which corresponds to an upper position of the stirrup  43 . 
   When, leaving this position, the user moves the plug  3  in the direction of the base  2  along the axis X, the lugs  46 ,  47  engage in the ramps  16 ,  26  then move along ramps  16 ,  26  compressing the springs  62 . The distance between the upper wall  6  of the housing  5  and the base  2  and the portion  44  of the stirrup  43  decreases. It will be noted that the ramps  16 ,  26  permit an alignment and stability of the plug  3  and of the base  2  during the connection operation. 
   Simultaneously, the stirrup  43  moves along the ramps  57 ,  61 . In other words, the stirrup  43  carries out, relative to the housing  33 , a movement with 2 degrees of freedom, which is to say a translation along the axis X and a translation along the axis Z. This has the effect of amplifying the advance of the stirrup  43 , which is to say that the movement of the housing  33  relative to thee housing  5  is less than the movement of the stirrup  43  relative to the housing  5 . Thus, the penetration of the projections of the sealing cover into the recesses  40  of the cover  41  is limited, which reduces the force that the user must exert. In other words, the locking position is reached without requiring excess compression of the sealing cover. This permits decreasing the connection forces. The blades  53  compress and thus acquire the potential energy necessary for coupling the system to ensure thereafter the compression of the interfacial sealing cover of the base  2  and the cover  41 , as will be described later in more detail. 
   When, leaving this position, the user continues to advance the plug  3  in the direction of the base  2  along the axis X, the lugs  46 ,  47  reach the ends  16   b ,  26   b  of the ramps  16 ,  26 . This position is a critical locking position, in which the springs  62  and the blades  53  are stressed to the maximum. The ends  16   b ,  26   b  constitute hard points. The distance d 2  between the central portion  44  and the upper wall  6  of the housing  5  is a minimum. The stirrup  43  is in the lower position ( FIG. 5 ). 
   When the lugs  46 ,  47  have passed the ends  16   b ,  26   b  forming the end points, the springs  62  expand giving rise to movement of the stirrup  43  relative to the base  2  along the axis Z. The lugs  46 ,  47  engage in the recesses  20 ,  30 . The stirrup  43  is located in a locking position in which it is secured to the housing of the base  2 . The stirrup  43  is in the upper position ( FIG. 6 ). 
   In this position, the blades  53  expand, which has the effect of giving rise to a force directed along the axis X which gives rise to movement of the housing  33  relative to the stirrup  43  along the axis X. The housing  33  moves relative to the housing  5  along the axis X in the direction of the housing  5 . 
   During the connection operation, the projections of the interfacial sealing cover of the base  2  insert themselves by deformation into the conical recesses  40 . The potential energy stored by the blades  53  ensures the coupling and the minimum compression of the interfacial sealing cover. The return force of the blades  53  balances the insertion force of the electrical contacts  11 ,  39  and the compression forces of the interfacial sealing cover. The return to equilibrium of the blades  53  thus permits ensuring the coupling between the base  2  and the plug  3  as well as the compression of the interfacial sealing cover. 
   The interfacial compression force is thus controlled during locking. This permits guaranteeing a minimum compression of the interfacial sealing cover. The minimal compression is the compression necessary to ensure interfacial sealing. The compression can give rise to a sufficient penetration distance of the projections of the interfacial sealing cover of the base  2  into the conical recesses  40 . The minimal penetration distance is for example in the order of a tenth of a millimeter. 
   The blades  53  permit taking up play which can exist between the different pieces along the axis X. The connection operation thus permits guaranteeing interfacial sealing, the electrical connection and the locking, by controlling the forces, given the tolerance intervals, particularly during production, which can for example be of the order of a millimeter. This mechanism permits ensuring minimum compression of the interfacial cover despite the play which can exist between the different pieces. 
   There will now be described a disconnection operation of the base  2  and the plug  3  according to the embodiment. 
   When, leaving the locking position, a user exerts pressure on the stirrup  43  which returns it to the lower position, the lugs  46 ,  47  leave the recesses  20 ,  30 . In this position, the plug  30  and the base  2  are no longer secured together and a movement along the axis X permits disconnection. In this position, when the user releases the stirrup  43 , the stirrup  43  returns to its release position. 
   The connection and disconnection operations are carried out by manual action and do not require the use of a tool. 
   Other modifications are possible. 
   The connection can be an electrical connector of any type, and can be adapted for various applications. In particular, the shape of the housing of the base can be anything desired, the shape of the housing of the plug being adapted to permit connection of the base and the plug. The dimensions of the housing can be anything at all. The electrical contacts of the base can be male or female, the electrical contacts of the plug being adapted to permit the connection of the base and the plug. 
   The connection operation can be carried out by pushing on the stirrup  43 . In this case, the user places the front surface  38  of the housing  33  in line with the front surface  10  of the housing  5  and pushes on the stirrup  43 . When the lugs  46 ,  47  are located in line with the recesses  20 ,  30 , the user releases the stirrup  43  and the lugs engage in the recesses  20 ,  30 . It will be noted that in this modified connection operation, the lugs  46 ,  47  do not necessarily follow the ramps  16 ,  26 . 
   The inclination of the ramps  16  and  26  can be different. For example the ramps  16 ,  26  can be upwardly inclined. 
   The base  2  is not necessarily fixed relative to a structure and the connection and disconnection operations can be carried out as the case may be by movement of one of the plug-in parts, the plug or the base, relative to the other plug-in part, the base or the plug respectively, or by simultaneous movement of the two plug-in portions. 
   The shape of the housings, the number of electrical contacts, and their arrangement can be anything at all. 
   A visual reference (shown in  FIGS. 4 to 6 ) can permit the user to visualize in a simple way that the stirrup  43  is in the locked position. The visual reference can be provided on the housing  5  and comprises a word “NOT” disposed along the Z axis and a word “CONNECTED” disposed along the X axis. When the stirrup  43  moves along the X axis in the direction of the housing  5 , it progressively masks the word “NOT”. When the stirrup is disposed in the locking position or at least in line with the recesses  20 ,  30 , the word “NOT” is completely masked, the word “CONNECTED” being visible. The visual reference permits particularly facilitating the connection operation for a non-professional user. The visual reference can also permit the user to determine when he must release the stirrup when the connection operation is carried out by pushing on the stirrup. 
   Although the invention has been described with reference to a particular embodiment, it is quite evident that it is not in any way limited and that it comprises all the technical equivalents and means described as well as their combination if these latter are within the scope of the invention.