Abstract:
The invention relates to a connector ( 1 ) for detachably connecting an electrically conductive foil ( 10 ) to electrically conductive socket contacts ( 26 ) of a socket housing ( 3 ), wherein the foil ( 10 ) can be inserted into a contact receiving aperture ( 40 ) of the socket contact ( 26 ) and can be jammed therein.  
     Separation of connection and locking of the connector ( 1 ) is achieved in that, in addition to the socket housing ( 3 ), the connector comprises a foil housing ( 2 ) and the housings ( 2, 3 ) can be mutually connected, and in that prior to connection in a first foil slot ( 9 ) of the foil housing ( 2 ) and during connection via a second foil slot ( 11 ) of the socket housing ( 3 ), the foil ( 10 ) can be inserted without mating force into the open contact receiving aperture ( 40 ) of the socket contact ( 26 ), and in that the connector ( 1 ) can be locked and the foil ( 10 ) can be jammed by closing the contact receiving aperture ( 40 ) only after connection of the housings ( 2, 3 ).

Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates to an electrical connector for detachably connecting a foil to electrically conductive socket contacts of a socket housing  
         BACKGROUND OF THE INVENTION  
         [0002]    Electrical conductors in the form of conductive foils are increasingly finding their way into many fields of engineering, for example automotive engineering. In addition to low production costs, the advantages of these foils are their flexibility and low overall height and a high electrical loading capacity. The latter is a consequence of the high surface/volume ratio, in comparison to electrical conductors with a round cross-section, resulting in improved cooling of the conductors. The high electrical loading capacity can be used for higher currents or for relatively smaller conductor cross-sections having the same current carrying capability.  
           [0003]    Foils with a plurality of parallel conductor tracks correspond to conventional multi-core conductors. The interfaces with conventional conductors (for example cable harnesses) or with power consuming devices (for example electric motors or lighting fixtures) are a problem with foils as the conventional connecting techniques (for example soldering or welding) cannot be used. Therefore connectors are interposed, of which the contacts create a spring loaded connection to the conductor tracks of the foil and a connection to conventional current conductors.  
           [0004]    EP 0 926 778 A2 discloses a connector for detachably connecting an electrically conductive foil to electrically conductive socket contacts of a socket housing, wherein the foil can be inserted into contact receiving apertures of spring contacts of the socket contacts and can be jammed therein. In the the socket contact there are resilient points of contact in its aperture. A certain mating force, with which the foil has to be inserted into the aperture, is required to overcome them. However, this requires considerably stiffness of the foil, so thin and flexible foils cannot be used in this connector.  
           [0005]    An object of the invention is therefore to create an improved connector, a corresponding contact and an improved housing for detachably connecting a foil to a socket contact.  
         SUMMARY OF THE INVENTION  
         [0006]    This and other objects are achieved with respect to the connector wherein housings are connected when the socket contact is open and connection proceeds virtually without any mating force. The foil slot in the foil housing serves, because of its long guide length, to guide the foil exactly and with low friction. Consequently, and because of the open contact receiving aperture during connection of the housings, very thin and flexible foils, which are particularly inexpensive, can also be used.  
           [0007]    Closure of the contact receiving aperture, which is independent of the mating force-free connection of the housings, and jamming of the foil brought about thereby allows a high jamming force, ensuring good current conduction between foil and socket contact and secure locating of the foil in the connector.  
           [0008]    It is advantageous that the foil housing comprises a foil housing front wall, a foil housing base wall, a foil housing top wall and two identical foil housing side walls, the walls forming the foil housing which is open at the end and into which the socket housing is insertable with play. This results in a stable foil housing which is an important precondition for mating force-free insertion of the socket housing into the foil housing.  
           [0009]    An advantage of the invention is that the first foil slot is located in an outer foil receiving section and in a plurality of inner foil receiving sections arranged perpendicularly on the foil housing front wall and that the inner foil receiving sections each have a foil stop limiting the insertion depth of the foil. A long guide distance and a defined end position of the foil in the foil housing is thus achieved.  
           [0010]    It is advantageous that a respective lever receiving opening for a lever shaft of a lever are provided in the foil housing side walls, and that the lever receiving openings have a bearing slot opening them in the direction of the foil housing top wall, the width of the slot being smaller than the diameter of the lever receiving opening. The width of the bearing slot is dimensioned such that, because of the elasticity of the plastics material of the foil housing, the lever shaft snaps with light pressure through the bearing slots into the lever receiving openings. The lever is thus captively connected to the foil housing.  
           [0011]    As a result of the fact that the bearing slots have a funnel-shaped lead in surface toward the foil housing top wall, the lead in surface opening in a top wall opening of corresponding width, the lever shaft is guided to the lever receiving openings in a simple manner, and snaps therein.  
           [0012]    For a stable socket housing and for exact guidance thereof in the foil housing it is advantageous that the socket housing has a socket housing front wall, a socket housing back wall, two identical socket housing side walls, a socket housing base wall and a socket housing top wall, the socket housing fitting into the foil housing with play.  
           [0013]    It is also conceivable to configure the housings in such a way that the foil housing can be pushed into the socket housing and the pivoted shaft is mounted in the socket housing and the pivot lever can be locked to the foil housing.  
           [0014]    For the stability of the socket contact inserted into the socket housing it is advantageous that partition plates with identical spacing are provided in the socket housing parallel to the socket housing side walls, between which plates the socket contacts can be inserted through back wall openings. When inserted through the back wall openings the socket contacts are guided and protected against deformation by the partition plates.  
           [0015]    An advantageous development of the invention consists in that the second foil slot for inserting the foil is provided at the leading end of the socket housing in the socket housing front wall and front wall openings for inserting the inner foil receiving sections of the foil housing and indentations in the partition plates for enclosing and supporting the lever shaft are provided, the foil and the inner foil receiving sections being inserted and the lever shaft being enclosed when the housings are connected. When the housings are connected complementary components thus penetrate them, and this leads to multiple support of the foil and the lever shaft and therefore to their operational optimisation.  
           [0016]    It is advantageous that the lever is pivotal between an open and a closed position, the lever, which is resilient, snapping into its closed position after overcoming at least one locking nose arranged on the socket housing, so the lever and the connected housings are locked.  
           [0017]    Because of the locking according to the invention of the lever the connector cannot be loosened by vibration. This is important, above all, in the automotive sector. Instead of the two locking noses on the side walls of the socket housing just one can also be arranged in the centre of the back wall of the socket.  
           [0018]    As a result of the fact that a number of cams corresponding to the number of socket contacts is non-rotatably arranged on the lever shaft, owing to which cams the foil is subjected to a predetermined normal contact force via the spring contacts of the socket contacts when the lever is locked, the foil is simultaneously jammed with locking of the connector. Insertion and jamming of the foil are thus clearly separated and optimised in each case.  
           [0019]    It is also advantageous that the actuating force of the lever is determined as a function of its pivotal angle owing to the characteristic curve of the spring contacts and owing to the gradient of the contour of the cams. As the characteristic curve of the spring contacts of the socket contact and the gradient of the contour of the cam can vary within wide limits, the actuating force of the lever can be varied accordingly and designed as desired.  
           [0020]    A gradient of the contour of the cam decreasing with increasing cam travel serves to limit the actuating force of the lever.  
           [0021]    An important aspect of the invention consists in that the spring contacts comprise a first and a second spring region and the first spring region comprises a first and a second spring arm with free end faces arranged opposite one another with spacing. The spring contacts are designed in such a way that the desired progression of the characteristic curve of the spring and therefore a corresponding adjustment force of the lever is achieved by varying the dimensions of their components.  
           [0022]    The shape according to the invention of the spring contacts provides the advantage of great variability in their design. Therefore the characteristic curve of the spring can be influenced by the length and width of the first spring region and of the spring arms and by the spacing of the opposing free end faces thereof.  
           [0023]    Advantages also emerge from the fact that the socket contacts comprise the spring contacts, a securing section and a contact section, at least the securing section and the spring contacts being formed in one piece. The securing section brings about anchoring of the socket contact in the socket housing. The spring contacts provide the spring loaded connection of foil and socket contact. Their one-piece design with the securing section simplifies manufacture and reduces production costs. The contact section serves to connect the socket contact to other conductors, for example to conventional cables.  
           [0024]    As a result of the fact that the contact receiving aperture is limited by the second spring region and the second spring arm, the foil comes into contact with electrically conductive elements from both sides. The electrically conductive parts of the foils must therefore be arranged on the upper or lower side thereof. In the unlocked state of the connector the contact receiving aperture is completely open and does not offer any resistance when the foil is inserted.  
           [0025]    As the second spring region and the second spring arm comprise opposing protrusions, between which the foils are jammed when the connector is locked, the jamming force acts at certain points on the foil and consequently produces a high jamming pressure. This ensures good current conduction to the foil and adequate jamming thereof.  
           [0026]    It is advantageous that the contact sections are designed as contact pins, contact clips or crimp contacts. The connector according to the invention can thus be connected to a wide variety of conductors. Examples include inter alia printed circuit boards to which the contact pins are soldered, or webs to which the contact clips are connected, or cables which are bonded to the crimp contact.  
           [0027]    The fact that the securing sections are preferably designed in one piece with the contact pins and the contact clips and the crimp contacts are connected to other securing sections, preferably by laser welding, contributes to reducing the cost of the connector.  
           [0028]    As the securing sections comprise barbs on their upper and lower edge, they can be anchored with interlocking fit in the socket housing. Loosening of the socket contacts is thus reliably prevented. This is important, above all, in automotive use.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0029]    Further features of the invention can be found in the following description and the drawings in which embodiments of the invention are shown schematically, and in which:  
         [0030]    [0030]FIG. 1 is a perspective view of a cross-section through a closed and locked connector with a foil housing and a socket housing and a lever;  
         [0031]    [0031]FIG. 2 is a perspective view of the connector in FIG. 1 in the open state;  
         [0032]    [0032]FIG. 3 is a perspective view of the foil housing in FIG. 2, but without lever;  
         [0033]    [0033]FIG. 4 is a perspective view of the lever;  
         [0034]    [0034]FIG. 5 is a plane cross-section through the open connector in FIG. 2;  
         [0035]    [0035]FIG. 6 is a plane cross-section through the closed connector in FIG. 1;  
         [0036]    [0036]FIG. 7 is a side view of a socket contact with a contact pin;  
         [0037]    [0037]FIG. 8 is a graph of the actuating force of the lever and of the normal contact force over the travel of a spring contact;  
         [0038]    [0038]FIG. 9 is a perspective view of the socket pin contact in FIG. 7;  
         [0039]    [0039]FIG. 10 is a perspective view of a socket clip contact with a contact clip;  
         [0040]    [0040]FIG. 11 is a longitudinal section through a socket crimp contact with a crimp contact;  
         [0041]    [0041]FIG. 12 is a plan view of the socket crimp contact in FIG. 11;  
         [0042]    [0042]FIG. 13 is a perspective view of the socket crimp contact in FIG. 11;  
         [0043]    [0043]FIG. 14 is a perspective view of the spring contact of the socket crimp contact in FIG. 11; and  
         [0044]    [0044]FIG. 15 is a perspective view of a plug-in part of the socket crimp contact in FIG. 11.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0045]    [0045]FIG. 1 shows a cross-section through a connector  1  according to the invention in a perspective view. The connector  1  is shown in the closed and locked state. It has a foil housing  2  and a socket housing  3  which are inserted in one another and locked by a lever  4 .  
         [0046]    The foil housing  2  has a foil housing front wall  5 , a foil housing base wall  6 , a foil housing top wall  7  and two foil housing side walls  8 , which are not shown in FIG. 1. The walls  5 ,  6 ,  7 ,  8  form a foil housing  2  open at the back, into which the socket housing  3  can be inserted with play.  
         [0047]    The foil housing  2  has a first foil slot  9  for introduction of a foil  10 . The socket housing  3  has a second foil slot  11  aligning with the first foil slot  9  of the foil housing  2 . Both foil slots  9 ,  11  have broken edges at their entry, facilitating introduction of the foil.  
         [0048]    The first foil slot  9  is located in an outer foil receiving section  12  and in inner foil receiving sections  13  arranged vertically on the front wall  5  of the foil housing  2 . The inner foil receiving sections  13  are shown in FIG. 2. These comprise a foil stop  14  limiting the insertion depth of the foil  10 .  
         [0049]    There is preferably only a small amount of height play between the first foil slot  9  and the foil  10 , resulting in good guidance thereof.  
         [0050]    A respective lever receiving opening  15 , of which one is shown in FIG. 3, is arranged in the two side walls  8  of the foil housing  2 . These serve as bearings for a lever shaft  16  of the lever  4 . The lever receiving openings  15  are opened in the direction of the foil housing top wall  7  by a bearing slot  17 , the width of the bearing slot  17  being smaller than the diameter of the lever receiving opening  15 . The bearing slot  17  has a funnel-shaped lead in surface  18  ending in a top wall opening  19  of corresponding width.  
         [0051]    In the assembly position a lever shaft  16  passes through the top wall opening  19  and the funnel-shaped lead in surface  18  above the bearing slot  17 . With slight pressure on the lever shaft  16  the latter snaps into the lever receiving opening  15  while exploiting the elasticity of the plastics material of the foil housing  2 . Consequently the lever  4  is captively connected to the foil housing  2 .  
         [0052]    The socket housing  3  has a socket housing front wall  20 , a socket housing back wall  21 , two identical socket housing side walls  22 , a socket housing base wall  23  and a socket housing top wall  24 . The walls  20 ,  21 ,  22 ,  23 ,  24  ensure the stability of the socket housing  3 , so an optimum precondition for exact guidance in the foil housing is provided.  
         [0053]    Partition plates  25  with identical spacing and forming narrow gaps for socket contacts  26 ,  27 ,  28 , are provided in the socket housing  3  parallel to the socket housing side walls  22 . Each of these gaps has a back wall opening  29  in the socket housing back wall  21 , through which the respective socket contact  26 ,  27 ,  28  is inserted. During insertion and operation these socket contacts are guided and protected against deformation by the partition plates  25 .  
         [0054]    The second foil slot  11  for inserting the foil  10  and front wall openings (not shown) for inserting the inner foil receiving sections  13  of the foil housing  2 , are provided on the leading end of the socket housing  3  in the socket housing front wall  20 . In addition, indentations  30 , serving to enclose and support the lever shaft  16  so the latter cannot bend under load, are arranged in the leading ends of the partition plates  25 . The foil  10  and the inner foil receiving sections  13  are inserted and the lever shaft  16  enclosed virtually without mating force when the housings  2 ,  3  are connected.  
         [0055]    The lever  4  is pivotal about approximately 180° between an open and a closed position. As it is resilient it can snap into its closed position after overcoming two locking noses  31 . The locking noses  31  are provided at the upper, foil-remote corners of the socket housing side walls  22 . A closing face  32  thereof is arranged somewhat set back with respect to the socket housing back wall  21 . The locking force of the lever  4  presses thereon. The two housings  2 ,  3  are fixed owing to the lever  4  snapping into its closed position. In this state the socket housing front wall  20  is securely attached to the inner side of the foil housing front wall  5 .  
         [0056]    Parallel, identically oriented cams  33  are nonrotatably arranged on the lever shaft  16 , as can be seen in FIG. 4. The number and position of the cams  33  corresponds to the number and position of socket contacts  26 ,  27 ,  28 . When the lever  4  is locked the foil  10  is subjected to a predetermined normal contact force owing to the cams  33  via socket pin contacts  26 , as shown in FIG. 1 and  5 .  
         [0057]    The actuating force of the lever  4  is dependent on the spring characteristic curve of the socket contacts  26 ,  27 ,  28  and on the gradient of the contour of the cams  33 . As the gradient decreases with increasing cam travel, the actuating force of the lever  4  increases more slowly toward the closed position.  
         [0058]    The lever  4  is a retaining element designed as a transverse rod in the form of a lever shaft  16  which is connected to a closed clevis. The clevis has two longitudinal arms  54  and a transverse arm  55  arranged opposite the transverse rod. On an inner face the transverse arm  55  has a retaining face  56  with which the socket housing  3  is retained on the foil housing  2 . In the assembled state of the lever  4  the two longitudinal arms  54  are guided laterally along the foil housing  2 . In a retaining position the longitudinal arms  45  project in front of the foil housing  2  and enclose the socket housing  3  inserted into the foil housing  2 . In a simple embodiment only one longitudinal arm  54  is formed with a retaining face  56 , instead of the rotatably mounted pivoted clevis  4 .  
         [0059]    The plane sectional view in FIG. 5 shows the connector  1  in the open state. The socket housing  3  opposes the foil housing  2  with spacing in the insertion position.  
         [0060]    The tension lever  4  is snapped in the foil housing  2  and is in the open position with the cam  33 . The foil  10  is inserted in the first foil slot  9  and rests against the foil stop  14 .  
         [0061]    There is a socket pin contact  26  in the socket housing  3 . This consists of a spring contact  36 , a securing section  35  and a contact section  34  designed as a contact pin  37 .  
         [0062]    The securing section  35  is inserted into the socket housing  3  up to a contact stop  38  and owing to its barbs  39 , provided on an upper and a lower edge  52 ,  53  of the securing section  35 , is anchored with interlocking fit therein.  
         [0063]    The spring contact  36  has an open contact receiving aperture  40 . The second foil slot  11  is located in front of it. The indentation  30  for supporting the lever shaft  16  is shown above the spring contact  36 .  
         [0064]    The connector  1  is closed by connecting the housings  2 ,  3 . In the process the foil  10  passes through the second foil slot  11  into the open contact receiving aperture  40  and encloses the indentation  30 , supporting the lever shaft  16 . This takes place virtually without mating force.  
         [0065]    The connector  1  is locked by pivoting the lever  4  from its open position in FIG. 5 into its closed position in FIG. 6. In the process it resiliently overcomes the locking nose  31  and comes to rest on the closing face  32 . At the same time the cam  13  reaches its maximum travel and loads the spring contact  36 . As a result the contact receiving aperture  40  thereof is closed and the foil  10  inserted therein is jammed. The jamming region of the foil is stripped on both sides. Owing to the separate closing and locking of the connector  1  the former is carried out without mating force and the latter so as to be securely connected.  
         [0066]    [0066]FIG. 7 shows a socket pin contact  26  with a securing section  35 , a spring contact  36  and a contact pin  37  which together consist of one piece.  
         [0067]    The spring contact  36  consists of a first and a second spring region  41 ,  42 . The first spring region  41  branches in a first and a second spring arm  43 ,  44 . The spring arms  43 ,  44  have free end faces  45  arranged opposite one another with spacing.  
         [0068]    The first spring arm  43  has a first protrusion  46  which can be loaded by the cam  33 . The second spring arm  44  has a second protrusion  47  and the second spring region  42  a third protrusion  48  which are arranged opposite and facing one another and between which the stripped part of the foil  10  is jammed by the cam  33  via the first and second spring arm  43 ,  44  when the connector  1  is locked. A small jamming face for jamming the foil  10  is provided by the second and third protrusions  47 ,  48 .  
         [0069]    The small jamming face induces a high jamming pressure ensuring good current conduction between the spring contact  36  and the foil  10  and adequate jamming thereof.  
         [0070]    The contact receiving aperture  40  is limited by the second spring region  42  and the second spring arm  44 . As the spring contact  36  as a whole is current-carrying it is irrelevant whether the foil  10  is stripped in the jamming region on one side only or on both sides.  
         [0071]    [0071]FIG. 8 shows a graph in which the normal contact force a between the protrusions  47 ,  48  and the actuating force b of the lever  4  over the spring excursion s are shown.  
         [0072]    The spring excursion s is divided into three zones. In zone  1  only the first spring region  41  and the first spring arm  43  operate and, more precisely, proceeding from 0 mm spring excursion to contact of the foil  10  by the second spring arm  44 .  
         [0073]    In zone  2  the first spring region  41  and the first and second spring regions  43 ,  44  operate until the free end faces  45  contact one another.  
         [0074]    In zone  3  all three spring regions  41 ,  43 ,  44  operate, the spring arms  43 ,  44  acting as a unit and thus increasing the stiffness of the spring.  
         [0075]    Owing to the change in length and width of the spring regions  41 ,  43 ,  44  and by changing the spacing of the free end faces  45 , the normal contact force a and the actuating force b can be varied and optimised.  
         [0076]    [0076]FIG. 9 shows a socket pin contact  26  in a perspective view, comprising the contact pin  37 , the securing section  35 , the contact spring  36  and the contact receiving aperture  40 .  
         [0077]    [0077]FIG. 10 shows a socket clip contact in a perspective view. It differs from the socket pin contact  26  only in a contact clip  49  in place of the contact pin  37 . While the contact pin  37  is suitable for soldering to a printed circuit board, the contact clip  49  is placed on a web.  
         [0078]    [0078]FIG. 11 shows a longitudinal section through a socket crimp contact  28 . This comprises the spring contact  36  which, with another securing section  35 ′ forms a component. The other securing section  35 ′ can be inserted into a plug-in housing  51  and can be connected thereto by laser welding.  
         [0079]    The plug-in housing  51  is created by multiply folding a sheet metal board. It is formed as one piece with the crimp contact  50  which serves to connect a cable.  
         [0080]    [0080]FIG. 12 shows a plan view of the socket crimp  28 , comprising the spring contact  36 , the other securing section  35 ′, the plug-in housing  51  and the crimp contact  50 . The position of the laser welding spots can be seen in FIG. 12.  
         [0081]    [0081]FIG. 13 shows a perspective view of the socket crimp contact  28  clearly showing the assembled construction thereof.  
         [0082]    The socket crimp contact  28  is anchored in the socket housing  3  by means of a slip hook, not shown.  
         [0083]    [0083]FIG. 14 is a perspective view of the other securing section  35 ′ with the spring contact  36 , while FIG. 15 is a perspective view of the plug-in housing  51  comprising the crimp contact  50 , which are each designed in one piece.  
         [0084]    The connector according to the invention functions as follows:  
         [0085]    Firstly the lever  4  is snapped into the lever receiving openings  15  of the foil housing  2  in the open position. The foil  10  is then pushed into the first foil slot  9  up to the foil stop  14 . The socket contacts  26  or  27  or  28  are then pushed into the socket housing  3  and then the socket housing  3  is pushed with minimal mating force into the foil housing  2 . Finally, the lever  4  is pivoted from its open position into its closed position. Consequently the connector  1  is closed and locked, i.e. the housings  2 ,  3  are fixed and the foil  10  is jammed. A shakeproof, easily detachable connection to this foil is thus created.  
         [0086]    The person skilled in the art can also mount the lever  4  in the socket housing  3 , depending on the application. In this embodiment the associated foil housing  2  then has a corresponding locking nose  31  and closing face  32 .