Abstract:
A flat flexible cable connector ( 10 ) has a housing ( 31 ) with an insertion opening ( 33 ) in its front face. Two lengths of flexible cable ( 51   a,    51   b ) are placed end to end and are inserted into the opening. The connector has terminals ( 41 ) with top and bottom opposing contact portions ( 43   a,    44   a ) which are aligned with the exposed conductive leads on the two lengths of flexible cables. A moveable actuator ( 11 ) applies pressure to the terminal contact portions to effect a reliable connection between the flexible cables.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to a relay connector for not exclusively but preferably providing a connection between flat cables. 
         [0002]    Conventionally, relay connectors provide electrical connection between flat cables, each having flexibility and being often referred to as a flexible printed circuit (FPC) or a flexible flat cable (FFC). One such connector is described in Japanese Patent Application Laid-open (kokai) No. 6-203932).  FIG. 7  is a cross-sectional view illustrating an important part of such a conventional relay connector. 
         [0003]    As shown in  FIG. 7 , the connector has a housing  301  formed of an insulating material, and a plurality of terminals  302  held by the housing  301  which are formed of a conductive material. The terminals  302  are securely mounted, by press-fit, in terminal holding grooves formed in a cable insertion opening of the housing  301 . Each of the terminals  302  has, on each of the upper and lower sides thereof, a cantilever-like arm member extending from a main body seated in an innermost portion of the housing  301  toward the front face of the housing  301 . 
         [0004]    A first flat cable  303  and a second flat cable  306 , with their one ends disposed to be stacked one upon another, are inserted into the cable insertion opening of the housing  301 . The first flat cable  303  is provided with a plurality of conductive leads  304  formed on one surface (the lower surface as viewed in  FIG. 7 ) of a body formed of a strip-shaped insulating material, and an insulating layer  305  covering the surfaces of the conductive leads  304 . The second flat cable  306  is provided with a plurality of conductive leads  307  formed on one surface (the upper surface as viewed in  FIG. 7 ) of a body formed of a strip-shaped insulating material, and an insulating layer  308  covering the surfaces of the conductive leads  307 . An electronic component  309  is mounted on the first flat cable  303 , and terminals of the electronic component  309  are connected to the conductive leads  304 . 
         [0005]    The insulating layer  305  is partially removed at the end of the first flat cable  303  to expose the conductive leads  304  thereof, and the insulating layer  308  is partially removed for the same purpose at the end of the second flat cable  306 . Therefore, as shown in  FIG. 7 , by stacking the two ends of the cables together and inserting them as a single piece into the cable insertion opening of the housing  301 , the conductive leads  304  and  307  contact each other to establish an electrical connection to thereby connect together the first flat cable  303  to the second flat cable  306 . The upper and lower arm members of the terminals  302  urge the first flat cable  303  and the second flat cable  306  from above and from below, and the conductive leads  304  and  307  are pressed against each other to ensure a connection between the first and second flat cables  303  and  306 . A lock member (not shown) may be fit from behind the housing  301  in order that the upper and lower arm members of the terminals  302  are further pressed from above and from below by the lock member. This provides a sure connection between the two flat cables  303  and  306 . 
         [0006]    Nevertheless, in the above connector, a change in the electrical connecting resistance between the conductive leads  304 ,  307  might cause a change in the transmission characteristics of signals. That is, the conductive leads  304  and  307  are pressed together and connected to each other by the upper and lower arm members of the terminals  302 . However, according to careful observation of the connection of both conductive leads  304  and  307 , it is understood that, at a point corresponding to projected portions of the above-mentioned arm members contact of both conductive leads is ensured, but in a region lying in front of and behind the point, both may be alternately brought into contact with one another and separated apart from one another because of the uncertainty of contacting state. When the region of both conductive leads  304  and  307  that lie in front of and behind the point is in contacting state, the area of a portion in such a contacting state is rather large thereby decreasing the electric connecting resistance between the conductive leads  304  and  307 . When the above-mentioned region in front of and behind the point is separated apart to lose contact, the area of the portion in the contacting state becomes narrow thereby increasing the electric connecting resistance between the conductive leads  304  and  307 . Thus, the change in the electric connecting resistance between both conductive leads  304  and  307  could cause unstable transmission characteristics, resulting in becoming unable to stably transmit signals. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention has an object thereof to solve the above-mentioned problems, by providing a relay connector for flat cables having conductive leads exposed in a bare condition and mutually stacked so as to come face to face with each other. The connector includes terminals provided with pressing projections, a first arm portion and a second arm portion, each extending in a direction along which insertion and withdrawal direction of the flat cables are performed, and a connecting portion that connects the first arm portion and the second arm portion. Due to the described configuration, an attitude change of an actuator from a first position to a second position changes an angle of the first or second arm portion so that the pressing projection of the first arm portion or the pressing projection of the second arm portion is urged to displace toward a line of direction in which the insertion is performed. This results in the conductive leads of the respective flat cables forming together a contact point at a position corresponding to the pressing projections, and that these conductive leads are spaced apart when they come apart from the contact point in the insertion direction. Consequently, the connecting resistance between both conductive leads is constant, enabling acquirement of stable transmission characteristics of signals. 
         [0008]    To this end, a relay connector of the present invention includes: a housing provided with an insertion opening for permitting insertion of a first flat cable and a second flat cable having conductive leads exposed in a bare condition and stacked so as to come face to face with each other; terminals that are loaded into the housing, and which urge the first and second flat cables from both sides; and, an actuator secured to the housing which is movable between a first position for permitting insertion of the first and second flat cables, and a second position for effecting the electrical connection between conductive leads of the first and second flat cables. Each terminal is provided with pressing projections that press the first and second flat cable from both sides, and also has first and second arm portions that extend in an insertion direction of the first and second flat cables, and a connecting portion for connecting the first arm portion and the second arm portion. A change in movement of the actuator from the first to second position, causes a change in an angle of the first or second arm portion so that either the pressing projection of the first arm portion or the pressing projection of the second arm portion are displaced toward a line of a direction in which the insertion is performed. 
         [0009]    In a relay connector according to another embodiment of the invention, a clearance is defined between opposite surfaces of the first and second cables at tips thereof inserted into the insertion opening due a change in movement of the actuator from the first to the second position thereof. 
         [0010]    Further, in still another embodiment of the present invention, the conductive leads of the first and second flat cables inserted into the insertion opening form contact points where the conductive leads contact each other at a position corresponding to the pressing projections due to a change in movement of the actuator from the first to second position thereof. 
         [0011]    In a further embodiment of the present invention, the conductive leads of the first and second flat cables inserted into the insertion opening, are mutually kept apart except for at the contact point thereof. 
         [0012]    In accordance with the present invention, the relay connector is adapted for flat cable insertion with conductive leads exposed in a bare condition and stacked to come face to face with each other, has pressing projections, and a first and second arm portion, each extending along the insertion direction of the flat cables, and terminals each for connecting the first arm portion and the second arm portion. Movement of the actuator from the first position to the second position changes the angle of the first or second arm portion so that the pressing projections of the first or second arm portions are displaced in the insertion direction. The leads of the respective flat cables are formed at contact points at the position corresponding to the pressing projections, and that these leads are spaced apart in the insertion direction from the contact point. Consequently, the connection resistance between the leads is constant, permitting stable transmission characteristics of signals. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a perspective view of one embodiment of the present invention with its actuator in its open position; 
           [0014]      FIGS. 2A to 2C  are a top view, a front view, and a side view of the relay connector of  FIG. 1 ; 
           [0015]      FIG. 3  is a perspective view of the relay connector of  FIG. 1  with the actuator in its closed position; 
           [0016]      FIG. 4  is a sectional view of the connector of  FIG. 3  taken along A-A thereof; 
           [0017]      FIG. 5  is an enlarged detail view of area B of  FIG. 4 , with the actuator closed; 
           [0018]      FIGS. 6A to 6D  are diagrams schematically explaining the operation of terminals of the relay connector of the preferred embodiment of the present invention; and 
           [0019]      FIG. 7  is a cross-sectional view of a conventional relay connector. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0020]    In these drawing figures, the reference numeral  10  designates a connector which is a relay connector according to the present embodiment, which is used to provide connection between a first flat cable  51   a  and a second flat cable  51   b  that are called flexible printed circuits, flexible flat cables, or the like. In the present embodiment, the first flat cable  51   a  and the second flat cable  51   b  are connected to each other by inserting them into the connector  10 , with their respective ends stacked upon each other as shown in  FIG. 3 . The first and second flat cables  51   a  and  51   b  are stacked so that their surfaces on which conductive leads are formed, come face to face with each other. The cables  51   a  and  51   b  are of the same construction, and accordingly hereinafter, they will be commonly referred to as “flat cables  51 ”. Although the flat cables  51  are flat flexible cables called such as FPC, FFC, or the like, they may be of any type of flat cable provided with conductive leads. 
         [0021]    The connector  10  has a housing  31  integrally formed of an insulating material, and an actuator  11  that is also formed of an insulating material, and which is secured to the housing  31  so as to move thereon. That is to say, the actuator  11  is secured to the housing  31  so that it is able to move between an open position (first position), and a closed position (second position). 
         [0022]    The housing  31  has a lower part  32 , an upper part  35 , right and left side parts  36 , and an insertion opening  33 , through which one end of each flat cable  51  is inserted from front (obliquely lower on the left as viewed in  FIG. 1 ). The opening is formed among the lower part  32 , the upper part  35 , and the side parts  36 . The insertion opening  33  is provided with a plurality of terminal receiving grooves  34 , in which conductive terminals are loaded. In the interior of the opening  33 , as shown in  FIGS. 4 and 5 , an abutting part  38 , against which the tips of the flat cables  51  abut, is disposed between the neighboring terminal receiving grooves  34 . At this stage, for example, a total of forty such terminal grooves  34  are formed at a pitch of approximately 0.3 mm. The pitch and the number of the terminal grooves  34  may be suitably changed. The terminal receiving grooves  34  are not necessarily required to be entirely loaded with the terminals  41 . Thus, several terminals  41  may be omitted suitably depending upon the array of the conductive leads of the flat cables  51 . 
         [0023]    Stoppers  21 , in the form of auxiliary metal brackets, are loaded into both sides of the housing  31 . The stoppers  21  prevent the actuator  11  from being disengaged from the housing  31 . The stoppers  21  stop the movement of the actuator  11  by engaging side projections of the actuator  11 . 
         [0024]    The actuator  11  has a body portion  15  that is a substantially rectangular plate member, a plurality of terminal holes  12  formed in the body portion  15 , and shafts  17  formed in the terminal holes  12 . As shown in  FIG. 4 , an actuating lever portion  44   b  of the upper arm portion  44  of each terminal  41  is held in each of the terminal holes  12 . 
         [0025]    Referring to  FIGS. 4 and 5 , each terminal  41  has a substantially H-shape, and has a lower arm portion  43  as a first arm portion, and the upper arm portion  44  as a second arm portion, which extend in opposite insertion and withdrawal direction of the flat cable  51 , namely back and forth in the housing  31 , and an elongated strip-shaped connecting portion  45  that connects the lower arm portion  43  and the upper arm portion  44 . The connecting portion  45  is connected to a position between the lengthwise opposite ends of the lower arm portion  43 , and also connected to a position between the lengthwise opposite ends of the upper arm portion  44 . Here, the upper arm portion  44  is disposed above the lower arm portion  43 . 
         [0026]    The lower arm portion  43  has a tip-projecting portion  43   c  that projects forward from the side of the connecting portion  45 , a cable supporting portion  43   a  provided as a pressing projection protruding upward, and a bearing portion  43   b.  The cable supporting portion  43   a  are arranged at a position adjacent to the tip end of the lower arm portion  43  and disposed behind the tip projecting portion  43   c,  and the bearing portion  43   b  is connected to a position located behind the point at which the lower arm  43  is connected to the connecting portion  45 , and supports the shafts  17  from below. A tail portion  42  is connected to the rear end of the bearing portion  43   b.  Since the tail portion  42  projects downward at a portion thereof, as required, it may also be used as a substrate connecting portion to be connected to a connecting pad formed on a surface of the substrate by soldering or the like. The tip projecting portion  43   c  is formed, at its upper end thereof, with a projection  43   d  projecting upward. 
         [0027]    Each of the terminals  41  is inserted into a corresponding terminal groove  34  from the back side of the housing  31  (the right side in  FIG. 4 ). Each terminal  41  is secured to the housing  31  as follows. A substantially linear lower end of the lower arm portion  43  abuts against a floor surface of the terminal groove  34 , and the tip projecting portion  43   c  is press-fit between the lower surface of a terminal supporting member  32   a  disposed in the terminal groove  34  and the floor surface of the terminal groove  34 , and the projection  43   d  grips a portion of a ceiling surface of a lower surface hole portion of the terminal supporting member  32   a,  and further a projection  42   a  of the tail portion  42  grips a lower end of a rear edge at the lower part  32  of the housing  31 . 
         [0028]    The upper arm portion  44  functions as a movable pressing member that presses the flat cables  51  against the lower arm portion  43 , and has, in the vicinity of the tip thereof, a cable pressing portion  44   a  in the form of a pressing projection protruding downward. The upper arm portion  44  is further provided with an actuating lever portion  44   b  that extends toward the rear beyond the point at which the upper arm portion  44  is connected to the connecting portion  45 . The actuating lever portion  44   b  is arranged to enter into the terminal hole  12  of the actuator  11  thereby to control any upward movement of the shaft  17 . 
         [0029]    Each of the shafts  17  is elliptical or rectangular in cross-section, and is interposed between the bearing portion  43   b  and the actuating lever portion  44   b.  Each shaft  17  functions as a cam when it is rotated. In the open position, the shaft  17  pushes up the actuating lever portion  44   b  because it is positioned substantially a right angle, as shown in  FIG. 4 . When the actuating lever portion  44   b  is pushed up, the connecting portion  45  and its surroundings are resiliently deformed, and the entire upper arm portion  44  is rotated to change a relative angle defined between the upper arm portion  44  and the lower arm portion  43 , so that the tip of the upper arm portion  44  is shifted downward. Thus, the cable pressing portion  44   a  is shifted coming close to the cable supporting portion  43   a , and is then pressed against the flat cables  51 . 
         [0030]    When the actuator  11  is in the open position, the shaft  17  is positioned at an angle of substantially level position, so that the actuating lever portion  44   b  is not pushed up, and the tip of the upper arm portion  44  is not shifted downward. Therefore, a sufficiently large space is provided between the cable pressing portion  44   a  and the cable supporting portion  43   a,  thereby enabling the ends of the flat cables  51  to be inserted in the opening  33  under no or slight contact pressure from the cable pressing portion  44   a  and the cable supporting portion  43   a.  This realizes a substantially DT (zero insertion force) structure. 
         [0031]    A description of the operation of connecting the flat cables  51  will be provided hereinbelow. 
         [0032]      FIG. 6  schematically explains the operation of the terminals of the relay connector of the present invention. 
         [0033]    In each first and second flat cable  51   a , 51   b,  a plurality of forty conductive leads in the shape of a foil having conductivity are arranged side by side at a predetermined pitch, for example, about 0.3 mm, on an insulating layer exhibiting electrical insulating property. Another insulating layer covers the upper surfaces of the conductive leads. On the side of the end portion of the first flat cable  51   a  and the end portion of the second flat cable  51   b  which are inserted into the insertion opening  33  of the connector  10  (their respective right end portions as viewed in  FIG. 4 ), namely on the side of the tip portion, the insulating layers are removed to expose the upper surfaces of the conductive leads in a bare condition over a predetermined range of length from the respective extreme tips. On the side of the tip portions of the first and second flat cables  51   a  and  51   b,  their respective surfaces where the conductive leads are arranged are stacked in face-to-face relationship. Specifically, in the range of barely exposed the upper surfaces of the conductive leads, the conductive leads of the first and second flat cables  51   a , 51   b  are stacked face to face with each other. At this stage, the tips of the first and second flat cable  51   a , 51   b  may be provided, on both sides thereof, with ears (not shown) formed to project outward, respectively. 
         [0034]    An operator inserts the respective tips of the first and second flat cables stacked together, into the insertion opening  33  of the housing  31 . As shown in  FIGS. 1 and 2 , the actuator  11  is brought into the open position thereof in advance. Therefore, a predetermined range from the extreme tips of the first and second flat cables  51   a  and  51   b  can be inserted into between the upper arm portion  44  and the lower arm portion  43  of each terminal  41  held within the corresponding terminal groove  34 . 
         [0035]    Although in the example shown in the drawings, the first flat cable underlies the second flat cable, the first flat cable may overlie the second flat cable. The tips of the first and second flat cable each abut against the abutting part  38  positioned within the terminal groove  34 . Thus, the lengthwise positioning of the flat cables  51  is performed, so that the insertion of the first and second flat cables is completed. 
         [0036]    Subsequently, the operator manually operates the actuator  11  to change the open position of the actuator  11  ( FIG. 1 ) into the closed position ( FIG. 3 ). At this time, the actuator  11  is shifted in a clockwise direction in  FIG. 2C  to thereby be able to change its movement into the closed position. 
         [0037]    The body portion  15  of the actuator  11  is rotated to produce a state substantially parallel to the insertion direction of the first and second flat cables, as shown in  FIGS. 3 and 4 . The shaft  17  is also rotated to a substantially right angle, as shown in  FIG. 4 . That is, the major axis of substantially elliptical or rectangular cross-section of the shaft  17  is positioned at a substantially right angle. 
         [0038]    Therefore, by the shaft  17 , the space between the bearing portion  43   b  and the actuating lever portion  44   b  is spaced apart, and the actuating lever portion  44   b  is pushed upward. Accordingly, the connecting portion  45  and its surroundings are resiliently deformed, and the entire upper arm portion  44  is rotated to change the relative angle defined between the upper arm portion  44  and the lower arm portion  43 , so that the tip of the upper arm portion  44  is shifted downward. Thus, the cable pressing portion  44   a  is shifted coming close to the cable supporting portion  43   a,  and is then pressed against the upper surface of the second flat cable  51   b , namely a surface opposite to the surface on which the conductive leads are arranged. As a result, the conductive leads barely exposed on the lower surface of the second flat cable  51   b  are pressed against the conductive leads barely exposed on the upper surface of the first flat cable  51   a.    
         [0039]    In this case, since the cable supporting portion  43   a  exists at a position opposed to the cable pressing portion  44   a,  the cable supporting portion  43   a  is pressed against the lower surface of the first flat cable  51   a,  namely the surface opposite to the surface having the conductive leads. As a result, the first and second flat cables are urged to a condition where they are sandwiched together from above and below by the cable pressing portion  44   a  and the cable supporting portion  43   a.  As best shown in  FIG. 5 , the conductive leads barely exposed on the upper surface of the first flat cable  51   a,  and the conductive leads exposed on the lower surface of the second flat cable  51   b  form a contact point  55  to provide a reliable electrical connection at a position corresponding to the cable supporting portion  43   a  and the cable pressing portion  44   a.    
         [0040]    On the other hand, on the side behind the contact point  55 , namely on the fore side viewing in the direction of insertion (i.e., the right side as viewed in  FIG. 5 ), the upper surface of the first cable  51   a  and the lower surface of the second cable  51   b  are spaced apart to leave a clearance C therebetween. On the side located in front of the contact point  55 , the leads of the first cable  51   a  and the leads of the second cable  51   b  are spaced apart to provide no electrical connection. Likewise, on the side in a counter-insertion direction from the contact point  55 , namely on the rear side of the contact point  55 , the upper surface of the first cable  51   a  and the lower surface of the second cable  51   b  are spaced apart to leave a clearance D. That is to say, on the rear side of the contact point  55 , the conductive leads of the first cable  51   a  and the conductive leads of the second cable  51   b  are also spaced apart to provide no electrical connection. 
         [0041]    This is because, when the cable pressing portion  44   a  of the upper arm portion  44  is pressed against the upper surface of the second flat cable  51   b,  it is displaced in the insertion direction, namely toward the front end of the second flat cable  51   b.  In the present embodiment, the dimension and the shape of the terminals  41  are adjusted in order to achieve the following movements. That is, when the cable pressing portion  44   a  is moved to come close to the cable supporting portion  43   a  in response to the attitude change of the actuator  11  from the open position to the close position thereof, the position of the cable pressing portion  44   a  with respect to the insertion direction is shifted rightward as viewed in  FIG. 5 , from the time that the cable pressing portion  44   a  contacts with the upper surface of the second flat cable  51   b  until completion of the movement thereof. 
         [0042]      FIGS. 6A-6D  schematically and exaggeratedly illustrate the relationship between the movement of the upper arm portion  44  and the flat cables  51  when the cable pressing portion  44   a  is pressed against the upper surface of the second cable  51   b.  Specifically,  FIG. 6A  illustrates the movement of the upper arm portion  44 .  FIG. 6B  illustrates a state before the cable pressing portion  44   a  contacts with the upper surface of the second cable  51   b.    FIG. 6C  illustrates a state in which the cable pressing portion  44   a  is in contact with the upper surface of the second cable  51   b.    FIG. 6D  illustrates a state in which the actuator  11  is in the close position, and the cable pressing portion  44   a  is pressed against the upper surface of the second cable  51   b.    
         [0043]    When the actuator  11  is open, as shown in  FIG. 6B , the tip (its left end in the figures) of the upper arm portion  44  is directed to obliquely above. That is to say, on the basis of the direction of extension of the lower arm portion  43 , the elevation angle when the tip is viewed from the center of rotation of the upper arm portion  44 , namely the elevation angle of the extension direction of the upper arm portion  44  has a plus value. 
         [0044]    Subsequently, when the movement of the actuator  11  is changed from an open to a closed position, the entire upper arm portion  44  is rotated to change the relative angle defined between the upper arm portion  44  and the lower arm portion  43 . As a result, the elevation angle of the extension direction of the upper arm portion  44  on the basis of the extension direction of the lower arm portion  43  is reduced, and the tip of the upper arm portion  44  is shifted downward. When the elevation angle is zero, as shown in  FIG. 6C , the cable pressing portion  44   a  is brought into contact with the upper surface of the second flat cable  51   b.    
         [0045]    Subsequently, when the tip of the upper arm portion  44  is shifted further downward, the elevation angle of the extension direction of the upper arm portion  44  on the basis of the extension direction of the lower arm portion  43  has a minus value, thereby increasing the absolute value of the elevation angle. When the actuator  11  is moved to the close position, as shown in  FIG. 6D , the cable pressing portion  44   a  is brought into contact with the upper surface of the second flat cable  51   b.    
         [0046]    In this state, the elevation angle of the extension direction of the upper arm portion  44  on the basis of the extension direction of the lower arm portion  43  has a minus value having a large absolute value. The conductive leads barely exposed on the upper surface of the first cable  51   a  and the leads on the lower surface of the second cable  51   b  form contact points  55  to provide electrical connection therebetween in a manner such that the leads of the first and second flat cables confront, the cable supporting portion  43   a  and the cable pressing portion  44   a,  respectively. On the side in the insertion direction from the contact point  55 , the upper surface of the first cable  51   a  and the lower surface of the second cable  51   b  are spaced apart to leave the clearance C. On the side in the counter-insertion direction from the contact point  55 , the upper surface of the first flat cable  51   a  and the lower surface of the second flat cable  51   b  are spaced apart to leave the clearance D. 
         [0047]      FIG. 6A  illustrates the movements of the upper arm portion  44  shown in  FIGS. 6B-6D . The arrow E indicates the locus along which the cable pressing portion  44   a  is moved. The arrow F represents exaggeratedly the curvature of the arrow E by way of explanation. It will be seen from the arrow F that the cable pressing portion  44   a  is displaced by a distance G in the insertion direction, namely toward the front end of the flat cables  51 , from a state in which the cable pressing portion  44   a  is in contact with the upper surface of the second flat cable  51   b  as shown in  FIG. 6C , until a state in which the cable pressing portion  44   a  is pressed against the upper surface of the second flat cable  51   b  as shown in  FIG. 6D . 
         [0048]    Thus, the angle of the upper arm portion  44  is changed, and the cable pressing portion  44   a  is displaced in the insertion direction after making a contact with the upper surface of the second flat cable  51   b.  Hence, on the side in the insertion direction from the contact point  55 , the upper surface of the first flat cable  51   a  and the lower surface of the second flat cable  51   b  are spaced apart to leave the clearance C. This can be considered as follows. That is, the body of the first cable  51   a  and the body of the second cable  51   b  are flat members formed of material that is somewhat soft and has elastoplasticity, such as synthetic resin. Therefore, when a pin-point narrow range of the two bodies in the stacked state is pressed from above and from below, these bodies in this range are deformed so as to be in tight contact with each other, and the rest is deformed so as to separate from each other due to the affect of the deformation in this range. It can also be considered that because the upper surface of the second flat cable  51   b  is deformed in the insertion direction by the cable pressing portion  44   a,  the members constituting the bodies of the first and second flat cables are slightly slid in the insertion direction, thereby leaving the large clearance C on the side in the insertion direction from the contact point  55 . On the other hand, it seems that such a slight sliding of the above-mentioned members in the insertion direction leaves the clearance D smaller than the clearance C in the counter-insertion direction from the contact point  55 . 
         [0049]    When the actuator  11  is closed, the leads exposed on the upper surface of the first cable and the conductive leads exposed on the lower surface of the second cable are connected to each other to establish electrical continuity at the contact point  55 . Whereas in the range other than the contact point  55 , the two cables have no contact, thus causing no variation in the electric connecting resistance between the leads of the first and second flat cables. That is, the connecting resistance therebetween can be stabilized to produce stable transmission characteristics of signals. 
         [0050]    The extent of the first and second flat cables in which the insulating layers are removed to expose the upper surfaces of the conductive leads is a predetermined range from the extreme tip of the two cables. This range is slightly longer than the length from the abutting part  38  to the cable pressing portion  44   a  and the cabling supporting portion  43   a  in the terminal receiving grooves  34 . Therefore, the range in which the conductive leads are exposed is short on the side in the counter-insertion direction from the contact point  55 . Hence, even if the clearance D is small, there is no possibility of contact between the leads of the first and second flat cables. 
         [0051]    On the other hand, on the side in the insertion direction from the contact point  55 , the range in which the conductive leads are exposed is long enough to permit the leads to be exposed on the surfaces of the first and second cables over the entire range from the contact point  55  to the tip. However, the displacement of the cable pressing portion  44   a  in the insertion direction enables to leave a large amount of clearance C, thus eliminating any possibility of causing contact between the conductive leads barely exposed on the upper surface of the first flat cable  51   a  and the conductive leads barely exposed on the lower surface of the second flat cable  51   b.    
         [0052]    Although the case where the elevation angle in the extension direction of the upper arm portion  44  on the basis of the extension direction of the lower arm portion  43  is changed from plus to minus was described in detail by referring to  FIGS. 6A to 6D , it should be noted that the relative angle change between the upper arm portion  44  and the lower arm portion  43  is not limited to this. It is possible to employ any alternative way in which the displacement of the cable pressing portion  44   a  in the insertion direction allows for displacement of the upper surface of the second flat cable  51   b  in the insertion direction. For example, where the elevation angle in the extension direction of the upper arm portion  44  on the basis of the extension direction of the lower arm portion  43  has a minus value, the attitude change of the actuator  11  from the open position to the close position may change the elevation angle into a minus value having a large absolute value. 
         [0053]    Although in the foregoing description, the upper arm portion  44  is rotated by the movement of the actuator  11 , the lower arm portion  43  may be rotated. In this case, the cable supporting portion  43   a  approaches the cable pressing portion  44   a  and displaces in the insertion direction, allowing the lower surface of the first flat cable  51   a  to be displaced in the insertion direction. 
         [0054]    Thus, in the foregoing embodiment, each terminals  41  has a cable supporting portion  43   a  and a cable pressing portion  44   a  that press the first and second flat cables from opposite sides. The movement of the actuator  11  from the open to the closed position changes the angle of the lower arm portion  43  or the upper arm portion  44  so that the cable supporting portion  43   a  or the cable pressing portion  44   a  is displaced in the insertion direction. 
         [0055]    Thus, the conductive leads of the first and second flat cables form a contact point  55  and make contact with each other where the conductive leads confront the cable supporting portion and the cable pressing portions. These leads are spaced apart except for the contact point  55 . This enables the electrical resistance between these conductive leads to be kept constant, permitting stable transmission characteristics of signals. 
         [0056]    Particularly, provision of the large amount of clearance C between the opposed surfaces at the extreme tip of the first flat cable  51   a  and the extreme tip of the second flat cable  51   b  ensures a reliable prevention of any contact between the conductive leads except for at the contact point  55 . 
         [0057]    It is to be understood that the present invention is not limited to the foregoing embodiment but various changes and modifications will occur to a person skilled in the art, based on the concept of the present invention, which may be considered as coming within the scope of the present invention as claimed in the appended claims.