Abstract:
A cable connector for connecting a flat cable having lead wires to a circuit board including a housing carrying terminals and an actuator moveable between a first position to enable insertion of the flat cable and a second position to connect the lead wires to the terminals. The actuator has a main body and further includes first shafts extending from opposite sides of the main body as well as second shafts carried in positions for engaging at least part of the terminals. The first shafts are supported by first bearing parts on auxiliary connector securing members carried on opposite sides of the housing while the second shafts are supported by second bearing parts of the terminals engaging the second shafts. When the actuator is in the first position, moment forces are generated on the first shafts and second shafts respectively by the first bearing parts and the second bearing parts which oppose movement of the actuator from the first position to the second position. The housing also includes concave and convex side portions which interact with the first shafts to further assist in the retention of the actuator in the first position.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to a connector for a cable. Conventionally, in order to connect flat cables, being often referred to as a flexible printed circuit (FPC) or a flexible flat cable (FFC), and each having flexibility, a connector for a cable (hereinafter referred to as “cable connector”) such as an FPC connector and an FFC connector has been used (for example, refer to Utility Model Registration No. 3094560). 
         [0002]      FIG. 6  is a perspective view indicating a conventional cable connector. 
         [0003]    As shown in  FIG. 6 , the cable connector includes a housing  301  being formed of an insulating material such as synthetic resin or the like, and a plurality of first terminals  303  and a plurality of second terminals  304 , being formed of a conductive material such as metal or the like, and being held by the housing  301 . On the upper surface of the housing  301 , an actuator  302  being formed of insulating material such as synthetic resin or the like is disposed. The actuator  302  is rotatably mounted on the housing  301  and rotates between its open position as shown in the figure and its closed position as not shown in the figure. In a state in which the actuator  302  is situated in the open position, a flat cable  305  is inserted from opening parts of the housing  301 . When the flat cable  305  is inserted into the back of the opening part, the actuator  302  is then rotated up to the closed position by being operated by the operator&#39;s fingers or the like. 
         [0004]    Each of the first terminals  303  has an upper arm part  306  and a lower arm part  308 , each extending in a direction of insertion-and-extraction of the flat cable  305 , and the upper arm part  306  enters into a recessed groove  311  being formed in the actuator  302 . An interlocking block  312  being disposed within the recessed groove  311  is positioned within a rotary supporting recessed groove  307  being formed at the tip of the upper arm part  306 . When the actuator  302  rotates up to the closed position, the interlocking block  312  of rectangular cross section is rotated within the rotary supporting recessed groove  307 , thereby pressing the flat cable  305  downward. Thus, a connecting part exposed on the lower surface of the flat cable  305  is brought into contact with a projection at the tip of the lower arm part  308 , and is connected with the first terminal  303 . Similarly, the connecting part exposed on the lower surface of the flat cable  305  is also brought into contact with a projection at the tip of an arm part  309  provided by each of the second terminals  304 , and is connected with the second terminal  304 . 
         [0005]    In the above conventional cable connector, however, since a lock mechanism is not activated when the actuator  302  is in the open position, the actuator  302  unnecessarily rotates to the closed position upon insertion of the flat cable  305 , and thereby it becomes difficult to perform the operation of inserting the flat cable  305 . That is, when the actuator  302  is in the open position, the orientation of the actuator  302  is maintained under its own weight. Therefore, for example, if the flat cable  305  makes contact with the actuator  302  upon insertion of the flat cable  305 , the actuator  302  may rotate to the closed position by the impact of the contact. In this case, it is necessary for an operator to return the actuator  302  to the open position and repeat the operation of inserting the flat cable  305 , thereby complicating the operation. 
       SUMMARY OF THE INVENTION 
       [0006]    It is an object of the present invention, in order to solve the above-mentioned problem encountered by the conventional cable connector, to provide a user-friendly cable connector, in spite of a simple construction, by rendering an actuator capable of changing its orientation between a first position to enable insertion of a flat cable and a second position to electrically connect terminals with lead-wires of the inserted flat cable to prevent the actuator from unnecessarily changing its position from the first position to the second position in response to forces generated against the actuator as a result of insertion of the flat cable into the connector. 
         [0007]    To this end, a cable connector of the present invention comprises: a housing provided with inserting holes through which a flat cable is inserted; terminals being mounted on the housing and electrically connected to lead-wires of the flat cable; an actuator capable of changing its orientation between a first position to enable insertion of the flat cable and a second position to connect the lead-wires of the inserted flat cable to the terminals, the actuator having a main body nearly parallel to a direction of insertion-and-extraction of the flat cable in the second position, first shafts being disposed on both sides of the main body respectively and second shafts being disposed in positions corresponding to at least part of the terminals; and auxiliary connector securing members mounted on both sides of the housing respectively, wherein the auxiliary connector securing members have first bearing parts supporting the first shafts respectively, the part of the terminals has second bearing parts supporting the second shafts, and the actuator maintains its orientation in the first position under moment forces exerted on the first shafts and the second shafts by the first bearing parts and the second bearing parts respectively. 
         [0008]    In a cable connector according to another aspect of the present invention, in the first position, a difference in height between positions of points at which the first shafts abut on the first bearing parts and positions of points at which the second shafts abut on the second bearing parts is larger than a difference in height, when the actuator is removed, between positions of points at which the first bearing parts abut on the first shafts and positions of points at which the second bearing parts abut on the second shafts, wherein, since forces exerted on the first shafts by the first bearing parts and forces exerted on the second shafts by the second bearing parts are opposed to each other, and a point of action of the forces exerted on the first shafts by the first bearing parts is located ahead of a point of action of the forces exerted on the second shafts by the second bearing parts, with respect to a direction of movement of a front end of the main body when the actuator changes its orientation from the first position to the second position, a force to change its orientation in the opposite direction of the second position acts on the actuator under the forces exerted on the first shafts by the first bearing parts and the forces exerted on the second shafts by the second bearing parts. 
         [0009]    In a cable connector according to a further aspect of the present invention, the housing has concave portions and convex portions being formed at side parts, respectively wherein in the second position, the first shafts are accommodated in the concave portions respectively, and in the first position, ends of the first shafts abut on the convex portions respectively. 
         [0010]    Other objects, features and advantages of the invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a perspective view when an actuator of a cable connector in a preferred embodiment of the present invention is in the open position; 
           [0012]      FIG. 2  is a perspective view when the actuator of the cable connector in the preferred embodiment of the present invention is in the closed position; 
           [0013]      FIG. 3  is a cross-sectional view when the actuator of the cable connector in the preferred embodiment of the present invention is in the closed position, and an arrowed line sectional view A-A in  FIG. 2 ; 
           [0014]      FIG. 4  is a cross-sectional view when the actuator of the cable connector in the preferred embodiment of the present invention is in the closed position, and an arrowed line sectional view B-B in  FIG. 2 ; 
           [0015]      FIGS. 5A and 5B  are partial cross-sectional views when the actuator of the cable connector in the preferred embodiment of the present invention is in the open position; and 
           [0016]      FIG. 6  is a perspective view indicating a conventional cable connector. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0017]    Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 
         [0018]      FIG. 1  is a perspective view when an actuator of a cable connector in a preferred embodiment of the present invention is in the open position.  FIG. 2  is a perspective view when the actuator of the cable connector in a preferred embodiment of the present invention is in the closed position.  FIG. 3  is a cross-sectional view when the actuator of the cable connector in a preferred embodiment of the present invention is in the closed position, and an arrowed line sectional view A-A in  FIG. 2 .  FIG. 4  is a cross-sectional view when the actuator of the cable connector in a preferred embodiment of the present invention is in the closed position, and an arrowed line sectional view B-B in  FIG. 2 . 
         [0019]    In these figures, a reference numeral  10  designates a connector as a cable connector in the preferred embodiment, and the connector  10  is mounted on a surface of a substrate such as a circuit board or the like (not illustrated), and is used for electrically connecting a flat cable, which is not illustrated and referred to as a flexible circuit board, a flexible flat cable or the like. In this case, the lower surface as viewed in  FIGS. 3 and 4  is a mounting surface of the connector  10 , and is opposed to the mounting surface of the substrate. For example, the flat cable is a flat flexible cable being called as an FPC, an FFC, or the like, and any kind of cable is acceptable if it is a flat cable provided with lead-wires. In this embodiment, references to directions such as up, down, left, right, front, rear, and the like, used for explaining the structure and movement of each part of the cable connector  10 , are not absolute, but relative. These reference are appropriate when each part of the cable connector  10  is situated in the position shown in the figures. If the position of each part of the cable connector  10  changes, however, it is assumed that these references are to be changed according to the change in the position of each part of the connector  10 . 
         [0020]    At this moment, the connector  10  comprises a housing  31  being integrally formed of insulating material such as synthetic resin or the like, and an actuator  11  being integrally formed of insulating material such as synthetic resin or the like, and being mounted on the housing  31  so as to be able to change its orientation. That is, the actuator  11  is mounted on the housing  31  so as to change its position to be situated in the open position as a first position and the closed position as a second position. 
         [0021]    The housing  31  includes a lower part  32 , an upper part  35 , right and left side parts  36 , and inserting holes  33  being formed among the lower part  32 , the upper part  35 , and the side parts  36 , and serving as opening parts for inserting and extracting an end portion of the flat cable from the front (the left side as viewed in  FIGS. 3 and 4 ). The flat cable is inserted toward the right side as viewed in  FIGS. 3 and 4 . In this embodiment, for the sake of convenience, it is decided that each inlet side of the inserting holes  33  (the left side as viewed in  FIGS. 3 and 4 ) is referred to as the front side of the connector  10 , and each back of the inserting holes  33  (the right side as viewed in  FIGS. 3 and 4 ) is referred to as the rear side of the connector  10 . At the backs within the inserting holes  33 , an abutting part  38  on which the tip of the flat cable abuts is disposed. 
         [0022]    In the housing  31 , a plurality of terminal receiving grooves are formed in which metal terminals are fitted. In the present preferred embodiment, the terminals include a first terminal  41  and a second terminal  51 , and each of the terminal receiving grooves includes a first terminal receiving groove  34   a  in which the first terminal  41  is fitted, and a second terminal receiving groove  34   b  in which the second terminal  51  is fitted. In the example as shown in the drawings, the terminal receiving grooves in even-number positions are the first terminal receiving grooves  34   a , and the terminal receiving grooves in odd-number positions are the second terminal receiving grooves  34   b . For example, eleven pieces of the first terminal receiving grooves  34   a  and the second terminal receiving grooves  34   b  are formed in total at a pitch of about 0.3 mm. The pitch and the number of the terminal receiving grooves can be suitably changed. The first terminal receiving grooves  34   a  and the second terminal receiving grooves  34   b  are alternately disposed so as to be adjacent to each other. Further, the first terminals  41  and the second terminals  51  are not always required to be fitted in all the first terminal receiving grooves  34   a  and the second terminal receiving grooves  34   b , and it is possible to suitably reduce the number of first terminals  41  and the number of second terminals  51  based upon the arrangement of the lead-wires contained in the flat cable. 
         [0023]    In addition, side shoulder portions  37  are formed adjacent to the side portions  36  on both sides of the lower portion  32 . The side shoulder portions  37  are shoulder portions extending in the direction of inserting and extracting the flat cable, that is, in the direction of insertion-and-extraction of the flat cable, and the upper surfaces thereof are situated in a higher position than the upper surface  32   a  of the lower portion  32 . In the side shoulder portions  37 , slit-shaped auxiliary securing member receiving recess portions  39  extending in the direction of insertion-and-extraction of the flat cable are formed, and auxiliary connector securing members  21  being commonly known as nails are inserted into auxiliary securing member receiving recess portions  39 , thereby being mounted on the housing  31 . 
         [0024]    Preferably, the auxiliary connector securing members  21  are formed by providing a metal plate with machining such as punching, bending or the like. Each of the auxiliary connector securing members  21  includes a flat main body  22  extending in the direction of insertion-and-extraction of the flat cable and in the direction vertical to the mounting surface, and a locking portion  23  being integrally connected to the upper edge of the front end of the main body  22  and extending in a direction parallel to the mounting surface. The locking portion  23  is formed by bending a member projecting above from the upper edge of the front end of the main body  22  so that the tip edge  23   a  may be directed to the inside of the housing  31 . Consequently, the right and left locking portions  23  are formed so that each other&#39;s tip edge  23   a  may face each other. In addition, since the locking portions  23  are integrally connected to the main body  22  through bending portions, the locking portions  23  can resiliently be deformed to a certain degree, and the right and left tip edges  23   a  can be displaced in the right and left direction. 
         [0025]    Each of the tip edges  23   a  is linear, and is formed so as to be inclined to the direction of insertion-and-extraction of the flat cable. More particularly, the tip edge  23   a  is formed so that the part may be inclined to a center line extending in the anteroposterior direction of the housing  31  on the surface parallel to the mounting surface, and the extension line thereof may cross the center line ahead of the housing  31 . The right and left locking portions  23 , including the tip edges  23   a , are disposed so as to be symmetric to the center line. Thus, the distance between the right and left tip edges  23   a  is wider at the backs of the inserting holes  33 , namely at the rear side, and narrower at the inlet sides of the inserting holes  33 , namely at the front side. The side surfaces  37   a  of the right and left side shoulder portions  37 , and the front side ends of the tip edges  23   a  function as the guides of the inserting holes  33 . 
         [0026]    The auxiliary connector securing members  21  also have mounting portions  24  to be described later, which are connected to the lower ends of the main body  22  and the mounting portions  24  are fixed on the surface of the substrate by soldering or the like. This reinforces the mounting of the connector  10  on the substrate, preventing the connector  10  from disengaging from the substrate. 
         [0000]    The auxiliary connector securing members  21  are further provided with first bearing parts  25  to be described later, which are formed at the upper end behind the locking portions  23  in the main body  22 . The first bearing parts  25  extend in the direction of insertion-and-extraction of the flat cable, and support the first shafts  13   a  being formed on both sides of the main body  15  of the actuator  11  from below. 
         [0027]    Thus, the actuator  11  includes the main body  15  being a nearly rectangular thick plate member, a plurality of terminal accommodating recess parts being formed in the main body  15 , the first shafts  13   a  as shafts being formed so as to project outward from both sides of the main body  15 , the plate-like locked portions  16  being formed so as to project outward from both sides of the main body  15 , as in the case of the first shafts  13   a , and pressing parts  14  being disposed on the lower face of the main body  15 . The pressing parts  14  press the flat cable being inserted from the inserting holes  33  downwardly, namely toward the direction of the mounting surface, when the actuator  11  is situated in the closed position. The pressing parts  14  also enable insertion of the flat cable when the actuator  11  is situated in the open position. 
         [0028]    The first shafts  13   a  being formed so as to project outward from both sides of the main body  15  are situated in the positions opposite to the right and left side parts  36  of the housing  31 , however, on the other hand, when the actuator  11  is situated in the closed position, as shown in  FIG. 2 , the first shafts  13   a  are situated in the positions corresponding to concave portions  36   a  being formed on the inside of the side parts  36 . At this time, the first shafts  13   a  are supported by the first bearing parts  25 , with no abutment on the side parts  36 . 
         [0029]    On the inside of the side parts  36 , the concave portions  36   a , tilting parts  36   b , and convex portions  36   c  are formed so as to sequentially line in the direction of insertion-and-extraction of the flat cable. When the actuator  11  changes its orientation from the closed position to the open position, the ends of the first shafts  13   a  abut on the convex portions  36   c , while being guided by the tilting parts  36   b . The distance between the opposed right and left convex portions  36   c  is shorter than the distance between the respective ends of the right and left first shafts  13   a . Consequently, when the actuator  11  is situated in the open position, the actuator  11  is pinched from both sides by the right and left convex portions  36   c , enabling the actuator  11  to be held in the open position. 
         [0030]    Each of the terminal accommodating recess parts contains a first terminal accommodating recess part  12   a  for accommodating a backstop  44   a  lying at the tip of an upper arm part  44  of the first terminal  41 , and a second terminal accommodating recess part  12   b  for accommodating a second bearing part  54   a  lying at the tip of an upper arm part  54  of the second terminal  51 . The number and the position of the first terminal accommodating recess parts  12   a  and the second terminal accommodating recess parts  12   b  correspond to the first terminal receiving grooves  34   a  and the second terminal receiving grooves  34   b . In addition, as shown in  FIG. 4 , a second shaft  13   b  of the actuator  11  is disposed in each of the second terminal accommodating recess parts  12   b , and the second shafts  13   b  are engaged with the second bearing parts  54   a . Since the second bearing parts  54   a  support the second shafts  13   b  from above, shifts of the second shafts  13   b  to the upward direction are limited. Therefore, the second bearing parts  54   a  prevent the actuator  11  from disengaging from the housing  31 . 
         [0031]    Then, as shown in  FIG. 2 , the main body  15  becomes approximately parallel to the direction of insertion-and-extraction of the flat cable when the actuator  11  is situated in the closed position, and as shown in  FIG. 1 , the main body  15  forms an angle of 90 degrees or more with respect to the direction of insertion-and-extraction of the flat cable when the actuator  11  is situated in the open position. 
         [0032]    Furthermore, when the actuator  11  is situated in the closed position, the locked portions  16  are formed in the positions anterior to the first shafts  13   a  so as to engage with the locking portions  23 . In this case, as shown in  FIG. 2 , the locking portions  23  hang over the locked portions  16 , preventing the actuator  11  from changing its orientation from the closed position to the open position. That is to say, the locked portions  16  and the locking portions  23  function as locking mechanisms for locking the actuator  11  in the closed position and preventing the actuator  11  from being opened. The tip edges  16   a  of the locked portions  16  are linear and formed so as to be parallel to the direction of insertion-and-extraction of the flat cable. To be more specific, the tip edges  16   a  are parallel to a center line extending in the anteroposterior direction of the housing  31  on the surface parallel to the mounting surface. 
         [0033]    Then, as shown in  FIG. 3 , each of the first terminals  41  has an approximately U shape, and contains a lower arm part  43  as a first arm part and an upper arm part  44  as a second arm part, extending in the direction of insertion-and-extraction of the flat cable, and a connecting part  45  extending in a direction perpendicular to the direction of insertion-and-extraction and linking the base part of the lower arm part  43  and the base part of the upper arm part  44 . 
         [0034]    At this moment, the lower arm part  43  functions as a contact piece electrically connected to the lead-wires of the flat cable, and contains a contacting part  43   a  projecting in the vicinity of the tip thereof (the left end as viewed in  FIG. 3 ). In addition, to the rear end of the connecting part  45 , a tail part  42  is connected as a substrate connecting part, projecting downward and being connected to a connecting pad to be formed on the substrate surface by soldering or the like. Further, a projection  43   b  projecting downward is formed at the base part of the lower arm part  43 , and an abutting part  42   a  is formed at the front end of the tail part  42 . 
         [0035]    When the actuator  11  is situated in the closed position, the backstops  44   a  at the tips of the upper arm parts  44  enter into the first terminal accommodating recess parts  12   a  and press the pressing part  14  downwardly, namely toward the direction of the mounting surface. 
         [0036]    The first terminals  41  are then inserted and fitted in the first terminal receiving grooves  34   a  from the rear side of the housing  31  (the right side as viewed in  FIG. 3 ). In this case, the upper arm parts  44  and approximately linear upper end parts of the connecting parts  45  abut on the lower surface of the upper part  35 , the projections  43   b  grab the floor surfaces of the first terminal receiving grooves  34   a , and further the abutting parts  42   a  abut on the rear end surface of the lower part  32 , thereby the first terminal  41  being fixed to the housing  31 . 
         [0037]    As shown in  FIG. 4 , each of the second terminals  51  contains a lower arm part  53  as a linear first arm part extending in the direction of insertion-and-extraction of the flat cable, an upper arm part  54  as an approximately S-shaped second arm part, and a connecting part  55  extending in a direction perpendicular to the direction of insertion-and-extraction and being connected to a connecting portion between the base part of the lower arm part  53  and the base part of the upper arm part  54 . 
         [0038]    To the tips of the lower arm parts  53  (the left end as viewed in  FIG. 4 ), tail parts  52  are connected as substrate connecting portions, projecting downward and being connected by soldering or the like to connecting pads to be formed on the substrate surface. The lower arm parts  53  function as contact pieces being electrically connected to the lead-wires of the flat cable, and contain contact parts  53   a  formed so as to project upward between the tip and the base part thereof. On the other hand, a projection  52   a  projecting backward is formed at the rear end of the tail part  52 , and a projection  55   a  is formed at the upper edge of the front end of the connecting part  55 . 
         [0039]    The second bearing part  54   a  at the tip of the upper arm part  54  is connected through the tilting part  54   b  being formed so as to be situated obliquely upward from the base part side to the tip side. Thus, the second shafts  13   b  of the actuator  11  are engaged with the second bearing parts  54   a  and subjected to downward forces exerted by the second bearing parts  54   a.    
         [0040]    Then, the second terminals  51  are inserted and fitted in the second terminal receiving grooves  34   b  from the front side of the housing  31  (the left side as viewed in  FIG. 4 ). In this case, the approximately linear lower ends of the lower arm parts  53  abut on the floor surfaces of the second terminal receiving grooves  34   b , the projections  55   a  grip the lower surface of the upper part  35 , and further the projections  52   a  of the tail parts  52  grip the lower end of the front end surface in the lower part  32  of the housing  31 , and thereby the second terminals  51  is fixed to the housing  31 . 
         [0041]    Meanwhile, in the first terminals  41 , the tail parts  42  are situated at the rear end of the housing  31 , whereas in the second terminals  51 , the tail parts  52  are situated at the front end of the housing  31 . Then, as described above, the first terminals  41  and the second terminals  51  are alternately fitted in the housing  31 . For this reason, the alignment of the tail parts  42 , the tail parts  52 , and the connecting pads or the like being formed on the mounting surface of the substrate so as to correspond to said tail parts forms, when viewed from above the connector  10 , a zigzag form alternately being off in a transverse direction with respect to the direction of alignment of terminals, namely a direction perpendicular to the surfaces of  FIGS. 3 and 4 . Therefore, even if a pitch between the first terminal  41  and the second terminal  51  adjacent to each other is narrow, it is possible to widen the distance between the tail part  42  and the tail part  52 , and the distance between the connecting pads or the like corresponding to each of these tail parts. For this reason, it is possible to manufacture the connecting pads or the like with ease, and also to prevent the formation of a solder bridge to avoid any short-circuit from arising between the adjacent connecting pads, at the time of soldering the tail part  42 , the tail part  52 , and connecting pads or the like corresponding to said tail parts. 
         [0042]    Further, in each of the second terminals  51 , the position of the contact part  53   a  with respect to the direction of insertion-and-extraction of the flat cable is situated nearer the rear end of the housing  31  than the position of the contact part  43   a  in the first terminal  41 . This aims for equalizing the electrical resistance at the first terminal  41  and the second terminal  51  by approximately equalizing the length of the electrically-conducting path from the contact part  43   a  to the tail part  42 , to the length of the electrically-conducting path from the contact part  53   a  to the tail part  52 . Since this separates the positions at which the adjacent lead-wires of the flat cable are electrically connected to the first terminals  41  and the second terminals  51  respectively, it enables to prevent the crosstalk between the adjacent lead-wires from generating. 
         [0043]    As shown in  FIG. 1 , when the actuator  11  is situated in the open position, the pressing parts  14  are directed obliquely upward. Since the distance between the actuator  11  and the contact part  43   a  of the first terminals  41 , and the distance between the actuator  11  and the contact part  53   a  of the second terminals  51  are sufficiently wide, the end of the flat cable being inserted from the inserting hole  33  is inserted without being subjected to any contact pressure or with being subjected to a slight contact pressure from the contact parts  43   a  and the contact parts  53 . Therefore, a formation of ZIF (Zero Insertion Force) structure is thereby substantially realized. 
         [0044]    Next, the force exerted on the actuator  11  being situated in the open position when the flat cable is not connected will be described. 
         [0045]      FIGS. 5A and 5B  are partial cross-sectional views of a state in which, the actuator of the cable connector in the preferred embodiment of the present invention is situated in the open position.  FIG. 5A  is a partial cross-sectional view depicting sites of the second terminals, and  FIG. 5B  is a partial cross-sectional view depicting sites of the auxiliary connector securing members. 
         [0046]    In the present embodiment, the tail parts  42  of the first terminals  41  and the tail parts  52  of the second terminals  51  are connected by soldering to the conductive pads or the like being formed on the surface of the substrate, and the mounting parts  24  of the auxiliary connector securing members  21  are connected by soldering to the connecting pads being formed on the surface of the substrate, and thereby the connector  10  is mounted on the surface of a substrate such as a circuit board or the like. 
         [0047]    Before connecting the flat cable, the actuator  11  is set to the open position, as shown in  FIGS. 5A and 5B . In this case, the first shafts  13   a  of the actuator  11  abut on the abutting surfaces of the first bearing parts  25  of the auxiliary connector securing members  21  and are supported from below, whereas the second shafts  13   b  abut on the abutting surfaces of the second bearing parts  54   a  of the second terminals  51  and thereby upward movement thereof is limited. A difference in height between the positions of the lower ends of the first shafts  13   a  and the positions of the upper ends of the second shafts  13   b  when the actuator  11  is situated in the open position is larger than a difference in height between the positions of the abutting surfaces of the first bearing parts  25  of the auxiliary connector securing members  21  and the positions of the abutting surfaces of the second bearing parts  54   a  of the second terminals  51  when the actuator  11  is removed. Therefore, when the actuator  11  is situated in the open position, the second bearing parts  54   a  are in a state of being pressed upward by the second shafts  13   b , and the upper arm parts  54  of the second terminals  51  are in a state of being resiliently deformed. 
         [0048]    Thus, in the second bearing parts  54   a  being disposed at the tips of the upper arm parts  54 , a force as indicated by the arrow C in  FIG. 5A  is generated by spring forces that the flexibly-deformed upper arm parts  54  exert in order to return to the shape that it used to have. For this reason, the second shafts  13   b  are subjected to a downward force exerted by the second bearing parts  54   a  as indicated by the arrow D in  FIG. 5A . Hence, the first shafts  13   a  are subjected to an upward force exerted by the first bearing parts  25  as indicated by the arrow E in  FIG. 5B , as the reaction force against the force indicated by the arrow D. 
         [0049]    A point at which downward forces exerted by the second bearing parts  54   a  act on the upper surfaces of the second shafts  13   b , namely a point of action of the force indicated by the arrow D, and a point at which upward forces exerted by the first bearing parts  25  act on the lower surfaces of the first shafts  13   a , namely a point of action of the force indicated by the arrow E do not conform in the direction of insertion-and-extraction of the flat cable, that is, there is a displacement between the two points. Comparing the arrow D in  FIG. 5A  with the arrow E in  FIG. 5B , it shows that the point of action of the force indicated by the arrow D is located at the backs of the inserting holes  33 , and the point of action of the force indicated by the arrow E is located on the inlet sides of the inserting holes  33 . That is, with respect to the direction of movement of the front end of the main body  15  in case that the actuator  11  changes its orientation from the open position to the closed position, the point at which the downward forces exerted by the second bearing parts  54   a  act on the upper surfaces of the second shafts  13   b  is located behind, and the point at which the upward forces exerted by the first bearing parts  25  act on the lower surfaces of the first shafts  13   a  is located ahead. 
         [0050]    As the result, a moment causing the actuator  11  to change its orientation in the clockwise direction, as indicated by the arrow F in  FIGS. 5A and 5B , acts on the actuator  11 . That is, the force to cause the actuator  11  to change its orientation in the direction opposite to the closed position acts on the actuator  11 . Therefore, even if an external force such as vibration, shock, or the like is applied to the connector  10 , the actuator  11  does not unnecessarily change its position to the closed position. For example, when inserting a flat cable into the connector  10 , even if the flat cable abuts on the actuator  11 , the actuator  11  maintains its position, and does not move to the closed position as indicated by the chain double-dashed line G in  FIG. 5B . 
         [0051]    It is possible to easily adjust the positional relationship with respect to the direction of insertion-and-extraction of the flat cable between the point of action of the force indicated by the arrow D and the point of action of the force indicated by the arrow E, by changing, for example, the cross-sectional shape of the first shafts  13   a  in order to change its position in which the lower surfaces of the first shafts  13   a  abut on the abutting surfaces of the first bearing parts  25 . Similarly, it is possible to adjust the scale of the moment indicated by the arrow F by adjusting the positional relationship with respect to the direction of insertion-and-extraction of the flat cable between the point of action of the force indicated by the arrow D and the point of action of the force indicated by the arrow E. As can be seen from  FIGS. 5   a  and  5   b , first shafts  13   a  have noncircular cross sections with the contact points shown at the positional relationship of arrow E forward or ahead of the relative position of the centerline of second shafts  13   b  which is shown by arrow D. 
         [0052]    As described above, if the ends of the first shafts  13   a  abut on the convex portions  36   c  being formed on the side parts  36  of the housing  31 , it is also possible to retain the actuator  11  in the open position. For this reason, combined with the action of the force indicated by the arrow E, it is possible to more surely retain the actuator  11  in the open position. 
         [0053]    Thus, in the present preferred embodiment, the actuator  11  maintains its orientation in the open position under the moment generated by the forces exerted on the first shafts  13   a  and the second shafts  13   b  by the first bearing parts  25  and the second bearing parts  54   a  respectively. 
         [0054]    This can prevent the actuator  11  from unnecessarily changing its position to the closed position without complicating the construction of the connector  10 . Then, this can downsize the connector  10 , thereby enhancing the operability of the connector  10 . 
         [0055]    In the closed position, the force exerted on the first shafts  13   a  by the first bearing parts  25  and the force exerted on the second shafts  13   b  by the second bearing parts  54   a  act in opposite directions each other, and there is a displacement with regard to the direction of insertion-and-extraction of the flat cable between the point of action of the force exerted on the first shafts  13   a  by the first bearing parts  25  and the point of action of the force exerted on the second shafts  13   b  by the second bearing parts  54   a . For this reason, a moment to maintain the orientation of the actuator  11  being situated in the open position is generated. 
         [0056]    Furthermore, in the open position, the point of action of the force exerted on the first shafts  13   a  by the first bearing parts  25  is located ahead of the point of action of the force exerted on the second shafts  13   b  by the second bearing parts  54   a , with respect to the direction of movement of the front end of the main body  15  in case that the actuator  11  changes its orientation from the open position to the closed position. Therefore, the moment as indicated by the arrow F in  FIGS. 5A and 5B , to render the actuator  11  to change its orientation in a clockwise direction, acts on the actuator  11 . 
         [0057]    Further, in the open position, under the force exerted on the first shafts  13   a  by the first bearing parts  25  and the force exerted on the second shafts  13   b  by the second bearing parts  54   a , the force to render the actuator  11  to change its orientation in the direction opposite to the open position acts on the actuator  11 . Therefore, even if an external force such as vibration, shock, or the like is applied to the connector  10 , the actuator  11  does not unnecessarily change its orientation to the closed position. 
         [0058]    Furthermore, in the open position, the difference in height between the positions of the points at which first shafts  13   a  abut on the first bearing parts  25  and the positions of the points at which the second shafts  13   b  abut on the second bearing parts  54   a  is larger than the difference in height between the positions of the points at which the first bearing parts  25  abut on the first bearing parts  13   a  and the positions of the points at which the second bearing parts  54   a  abut on the second shafts  13   b , when the actuator  11  is removed. Hence, the downward force as indicated by the arrow D in  FIG. 5A  is generated by spring forces such that the flexibly-deformed upper arm parts  54  exert in order to return to the shape that it used to have, and as the reaction force against said forces, the upward force as indicated by the arrow E in  FIG. 5B  is generated. 
         [0059]    While the present invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes and substitutions may be made and equivalents may be used without departing from the spirit and scope of the invention. It is therefore intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.