PATENT ABSTRACT
An electrical connector for connecting a sheet-like member includes a housing ( 1 ) defining an insertion slot ( 10 ); a plurality of terminals ( 2 ) arranged in the housing in parallel relationship with a predetermined pitch, each of the terminals having a contact beam ( 22 ) extending into the insertion slot and a pivot beam ( 21 ) extending substantially parallel to the contact beam; and an actuator ( 3 ) rotatably provided for establishing an electrical connection between the sheet-like member and the contact beams. The actuator provides cam portions ( 31 ) each interposed between every other the pivot beam. Each of the cam portions provides shaft portions ( 32 ) respectively adapted for pivotably engaging with the pivot beams disposed therebeside. The shaft portions extending towards each other respectively from two adjacent cam portions are spaced to define a gap ( 33 ) therebetween.

PATENT DESCRIPTION
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an electrical connector, and more particularly to an electrical connector for a sheet-like connection member such as a flexible printed circuit or cable (FPC), a flexible flat cable (FFC) and so forth. All of these cables and circuit hereafter will be generally referred to as “FPC” for simplification.  
         [0003]     2. Description of Related Art  
         [0004]     A conventional FPC connector generally includes a plurality of terminals each comprising a contact beam provided with a contact portion adapted for contacting an FPC and a pivot beam extending substantially parallel to and opposed to the contact beam, a housing adapted for holding the terminals and comprising opposite lower and upper walls defining a cavity therebetween wherein the lower wall protruding forwardly beyond the upper wall along a horizontal direction, and a pivoting actuator pivotably assembled on free ends of the pivot beams. The terminals are arranged in the housing in a side-by-side fashion, and each terminal has the contact beam thereof fixed in the lower wall of the housing and has the pivot beam thereof partly fixed in the upper wall of the housing, that is, the rear section of the pivot beam fixed in the upper wall and the front section of the pivot beam projected beyond the upper wall as a cantilever with no support. The front section of the pivot beam is provided with a concave portion for engaging with the actuator. The actuator is provided with cam portions disposed between every two adjacent pivot beams and shaft portions located between and joining every two adjacent cam portions. The shaft portions are respectively pivotably received in the concave portions of the pivot beams. Via engagement of the shaft portions of the actuator and the pivot beams of the terminals, the actuator is pivotable between an open position where an FPC can be inserted into the housing with zero-insertion-force and a closed position where the FPC is urged by the cam portions so as to connect with the contact portions of the contact beams. Such kind of FPC connectors can be found in U.S. Pat. Nos. 6,893,288, 6,755,682 and 6,099,346.  
         [0005]     However, the front sections of the pivot beams projected as cantilevers without any support are relatively weaker and apt to deform during assembly and operation of the actuator. Otherwise, the shaft portions each disposed between and joining two cam portions are breakable especially once being inadvertently struck during operation of the actuator. Therefore, it is desired to have a new FPC connector in which pivot beams are well supported and thereby are well strengthened.  
       SUMMARY OF THE INVENTION  
       [0006]     An object of the present invention is to provide a new FPC connector in which pivot beams of terminals are strengthened.  
         [0007]     In order to achieve above-mentioned object, an FPC connector for connecting an FPC in accordance with the preferred embodiment of the present invention includes a housing defining an insertion slot for receiving the FPC; a plurality of terminals arranged in the housing in parallel relationship with a predetermined pitch, each of the terminals having a contact beam extending into the insertion slot and a pivot beam extending substantially parallel to the contact beam; and an actuator rotatably provided for establishing an electrical connection between the sheet-like member and the contact beams. The actuator provides cam portions each interposed between every other the pivot beam. Each of the cam portions provides shaft portions respectively adapted for pivotably engaging with the pivot beams disposed therebeside. The shaft portions extending towards each other respectively from two adjacent cam portions are spaced to define a gap therebetween.  
         [0008]     Other objects, advantages and novel features of the present invention will become more apparent from the following detailed description of the present embodiment when taken in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is an assembled perspective view of an FPC connector in accordance with a first embodiment of the present invention;  
         [0010]      FIG. 2  is a partly exploded perspective view of the FPC connector shown in  FIG. 1 , wherein an actuator and a pair of support members are disassembled from a housing, but terminals are still assembled in the housing;  
         [0011]      FIG. 3 (A) is a cross-sectional view of  FIG. 1  taken along line  3 - 3 , wherein an actuator is placed at an open position;  
         [0012]      FIG. 3 (B) is a cross-sectional view similar to  FIG. 3 (A), but wherein the actuator has been rotated to a closed position;  
         [0013]      FIG. 4  is an assembled perspective view of an FPC connector in accordance with a second embodiment of the present invention;  
         [0014]      FIG. 5  is an exploded perspective view of the FPC connector shown in  FIG. 4 ;  
         [0015]      FIG. 6 (A) is a cross-sectional view of  FIG. 4  taken along line  6 - 6 , wherein an actuator is placed at an open position;  
         [0016]      FIG. 6 (B) is a cross-sectional view similar to  FIG. 6 (A), but wherein the actuator has been rotated to a closed position;  
         [0017]      FIG. 7  is a partly magnified view of the FPC connector shown in  FIG. 4 , specially showing installation of terminals in a housing thereof;  
         [0018]      FIG. 8  is a partly cut out perspective view of the FPC connector shown in  FIG. 4 ;  
         [0019]      FIG. 9  is an assembled perspective view of an FPC connector in accordance with a third embodiment of the present invention;  
         [0020]      FIG. 10  is a partly cut out perspective view of the FPC connector shown in  FIG. 9 ;  
         [0021]      FIG. 11  is a cross-sectional view of  FIG. 9  taken along line  11 - 11 , showing a warpage prevention device of the present invention; and  
         [0022]      FIG. 12  is a view showing a second kind of actuator of the present invention with an oval cross section. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0023]     The present invention will be discussed hereafter in detail in terms of the embodiments of the present invention. However, any well-known structure or feature is not shown in detail in order to avoid unnecessary obscurity of the present invention.  
         [0024]     Referring to  FIGS. 1-3 , description will be made as an FPC connector according to the first embodiment of the present invention. The FPC connector comprises an insulative housing  1 , a plurality of terminals  2 , an actuator  3 , and a pair of support members  4 . The FPC connector is provided with an FPC insertion slot  10  at the front portion thereof. A lower portion of the FPC insertion slot  10  is provided by a bottom wall  12  of the housing  1 , and an upper portion of the FPC insertion slot  10  is designed to be opened and closed by the actuator  3 .  
         [0025]     The terminals  2  are arranged in side-by-side relationship with a predetermined pitch from a rear side of the housing  1 . Each terminal  2  has a contact beam  22  and a pivot beam  21  parallel extending forwards from a base portion  20  and a solder foot  23  extending rearwards from the base portion  20 . Upon being installed in the housing  1 , the contact beam  22  extends along the bottom wall  12  in the lower portion of the FPC inserting slot  10 . The pivot beam  21  extends along an upper wall  11  of the housing  1  and has a front section thereof projecting beyond the front edge  110  of the upper wall  11 . The front section of the pivot beam  21  defines a concave portion  210  on the lower edge at the tip end thereof.  
         [0026]     There are finger portions  14  integrally projecting from the upper wall  11  of the housing  1  and each interposed between every other pivot beam  21  so as to laterally support the front sections of the pivot beams  21  therebeside. Otherwise, the actuator  3  is formed with a plurality of wedge portions  31  operable as cam portions adapted for pushing the FPC to firmly connect with the contact beams, each interposed between every other pivot beam  21  without the finger portion  14  interposed therebetween. Thus spaces between the pivot beams  21  of every two adjacent terminals  2  arranged side-by-side are alternately interposed with the finger portions  14  formed on the housing  1  and the cam portions  31  formed on the actuator  3 .  
         [0027]     Additionally, in order to engage with the concave portions of the pivot beams, the actuator  3  provides shaft portions  32  at two sides of each cam portion  31 . The shaft portions  32  extending from different cam portions  31  align with each other along a longitudinal direction of the actuator  3 , wherein the shaft portions  32  extending towards each other respectively from two adjacent cam portions  31  are spaced, defining a gap  33  therebetween for lodging the finger portion  14  of the housing  1 . That is to say, the shaft member of the actuator  3  is an incontinuous one that comprises several shaft portions  32  interrupted by the finger portions  14  of the housing  1 . In some certain extent, the shaft member of such an incontinuous structure has a better capability for resisting break. Once in assembly, the finger portions  14  fitly disposed in the corresponding gaps  33  between the shaft portions  32  and the shaft portions  32  pivotably accommodated in the corresponding concave portions  210  of the pivot beams  21  respectively. The actuator  3  further has a pair of bosses  34  on both ends thereof. Accordingly, the housing  1  defines a pair of recesses  15  in both side portions thereof to accommodate the bosses  34 . Assembling of the actuator  3  is performed by placing the shaft portions  32  respectively below the corresponding concave portion  210 , and then installing the support members  4  into the side portions  15  of the housing  1  respectively to support the bosses  34  of the actuator  3  from downward movement and therefore to maintain engagement between the shaft portions  32  and the pivot beams  21 .  
         [0028]     In assembly, the actuator  3  is rotatable between an open position as shown in  FIG. 3 (A) where an FPC (not shown) is allowed to be inserted into the FPC insertion slot  10  and a closed position as shown in  FIG. 3 (B) where the FPC is urged to electrically connect with the contact beams  22  of the terminals  2  through the cam portions  32 .  
         [0029]     In order to maintain the actuator  3  at the closed position thereof, there is a retention device between the actuator  3  and the housing  1 . The retention device comprises a pair of latches  36  provided by the actuator  3  and a pair of cutouts  17  provided by the housing  1 , wherein the latches  36  are respectively formed beside a main plate  35  of the actuator  3  and spaced from the main plate  35 , and the cutouts  17  are respectively defined below top flanges  16  extending from the side portions of the housing  1 , to communicate the entrance of the FPC insertion slot  10 . Each latch  36  has a protuberance  360  for engaging with the top flange  16 . The latches  36  are inwardly deflectable once inwardly pushed since the latches  36  are spaced from the main plate  35 . Thus, when the actuator  3  is rotated from the open position to the closed position, the protuberance  360  pushes through the top flange  16  into the cutout  17  and then remains therein. That prevents the actuator  3  from being reversely rotated and therefore maintains the actuator  3  at the closed position so as to keep the FPC being firmly connected with the contact beams  22  of the terminals  2 .  
         [0030]     Turning to  FIGS. 4-8 , description will be made as an FPC connector according to the second embodiment of the present invention. Similar parts are designated by like reference numbers.  
         [0031]     The FPC connector of the second embodiment comprises an insulative housing  1 , a plurality of terminals  2 , an actuator  3 , and a pair of support members  4  as well as the connector of the first embodiment, but has a larger length dimension than the connector of first embodiment due to more required terminals  2 .  
         [0032]     The housing  1  is provided with a plurality of terminal receiving grooves  13 , which comprises an upper groove  131  defined in an upper wall  11  of the housing  1  and a lower groove  132  defined in a bottom wall  12  of the housing  1 . The terminals  2  are respectively accommodated in the terminal receiving grooves  13  and therefore are arranged in side-by-side relationship with a predetermined pitch. As best shown in  FIGS. 6-8 , upon being installed in the housing  1 , the pivot beam  21  of the terminal  2  extends within the upper groove  131  and has a top surface thereof upwardly exposed to exterior as the upper groove  131  is upwardly opened in the upper wall  11 . The contact beam  22  of the terminal  2  extends within the lower groove  132  and has an upper surface thereof upwardly exposed to the FPC insertion slot and a bottom surface thereof downwardly exposed to exterior as the lower groove  132  is defined through the bottom wall  12  in the height direction thereof. Such a structure design minimizes height of the upper wall  11  and bottom wall  12  of the housing  1  and thus would reduce the whole height of the FPC connector, thereby forming a lower profile FPC connector. According to such a structure design, each terminal  2  in this embodiment further comprises a retaining protuberance  24  sideward protruding from the base portion  20  to be set in the housing  1 . Thus the installed terminals  2  can be firmly fixed in the housing  1  by engagement between the retaining protuberance  24  and the housing  1  and prevented from upward or downward rotation, which may occurs during opening and closing operation of the actuator  3 , since the pivot beams  21  are upwardly exposed and there is no support above the terminals  2  against upward rotation, and the contact beams  22  are downwardly exposed and there is no support below the terminals  2  against downward rotation. Additionally, this retaining protuberance  24  also prevents moments experienced by the terminal  2  from being transferred to the solder joint of the terminal  2  soldered on the printed circuit.  
         [0033]     Being distinguished from the first embodiment, in this embodiment, the pivot beam  21  is formed without concave portion and yet the finger portions  14  is provided with T-shaped head which defines a pair of inwards opened recesses  140  for respectively receiving a tip of the pivot beam  21  disposed therebeside, as best shown in  FIGS. 6-7 . In other words, the finger portion  14  in front of the recess  140  forms a lip portion to cover the corresponding pivot beam  21 . In assembly, the cam portions  31  are interposed between every other pivot beams  21  without finger portions  14  therebetween and each shaft portion  32  is supported below a corresponding pivot beam  21  from upward movement and behind a bottom portion of a corresponding recess  140  that receives the corresponding pivot beam  21  from forward movement. Thus the actuator  3  is rotatable between an open position as shown in  FIG. 6 (A) and a closed position as shown in  FIG. 6 (B).  
         [0034]     Turning to  FIGS. 9-11 , description will be made as an FPC connector according to the third embodiment of the present invention. Similar parts are designated by like reference numbers.  
         [0035]     The FPC connector of the third embodiment has the same finger portion  14  with T-shaped head as that of the second embodiment. However, the pivot beams  21  of the terminals  2  are not upwardly exposed to exterior except the tips thereof and the contact beams  22  are not downwardly exposed to the exterior except the tips thereof, which is distinguished from the second embodiment. Accordingly, the terminal  2  in this embodiment has no need for the retaining protuberance  24  as disclosed in the second embodiment since there are supports both above the pivot beams  21  and below the contact beams  22  to prevent the terminals  2  from upward or downward rotation.  
         [0036]     Above are three preferred embodiments of the present invention. Now a warpage prevention device of the present invention will be described alone hereafter. When the FPC connectors have a considerable length dimension, such as the FPC connectors in the second and third embodiment respectively as shown in  FIGS. 5 and 9 , the actuator  3  will accordingly be an elongated one and have a quite span along a longitudinal direction, thus a warpage is apt to occur to the actuator  3  during the molding process. In addition, if the actuator  3  is only supported by the bosses  34  at the two ends thereof and there is no other support device to hold up the middle portion of the actuator  3 , when the actuator  3  is in the open position, the middle portion of the actuator  3  is apt to drop down due to the weight thereof, causing a warpage of the actuator  3  along a direction denoted as arrow A. Such warpage of the actuator  3 , either occurs as a result of molding process or due to the weight thereof, will cause the middle portion of the actuator  3  to protrude towards and interfere with the FPC while the actuator  3  is in the open position. If this bad situation occurs, the FPC connector may not function with zero insertion force. In order to avoid such situation, a warpage prevention device is added to the FPC connector of the present invention. Referring to  FIGS. 9 and 11 , the instantiated warpage prevention device  8  comprises a convex guide surface  18  provided on the T-shaped head of the finger portion  14  and a cam follower  38  provided on the actuator  3 . The cam follower  38  could be supported upon the guide surface  18  to prevent the middle portion of the actuator  3  from interfering with the FPC when the actuator  3  is in the open position, and then could slide on the guide surface  18  while the actuator  3  is rotated between the open position and the closed position to guide the rotation movement of the actuator  3 . There would be more than one such warpage prevention devices  8 , and such warpage prevention devices  8  would be set in any proper position as the guide surface  18  would be provided on any one of the finger portions  14  and the cam follower  38  would be provided on any corresponding position of the actuator  3 .  
         [0037]     However, the disclosure is illustrative only, changes may be made in detail, especially in matter of shape, size, and arrangement of parts within the principles of the invention. For example, the shafts  32  of the actuator  3  of the present invention can be formed into a shape with an oval cross section and provided with function for pushing the FPC as well as the cam portion  31 , as shown in  FIG. 12 .