Abstract:
An electrical connector includes a housing, contact elements and locking members attached to the housing. The housing has a front end, a back end, a top side, a bottom side and a cavity between the top side and the bottom side. The cavity is to partially receive a circuit board therein. Each contact element is insertable into the housing along a direction from the bottom side towards the top side. Each locking member is insertable into the housing along a direction from the bottom side towards the top side. The upper and lower contact arms and the lock arm are resiliently deflectable away from the cavity to allow insertion of the circuit board into the cavity, and spring back when the circuit board is inserted into the cavity to make electrical connection to the circuit board and to lock the circuit board in the housing.

Description:
TECHNICAL FIELD 
     The present invention relates to an electrical connector and in particular, the present invention relates to an electrical connector for connecting to a flexible printed circuit board. 
     BACKGROUND 
     Flexible Printed Circuit (FPC) board or ribbon connectors are used in many electronic devices for establishing electrical connections between different modules/components in the device. To ensure reliable connection, the connector is typically provided with an actuator for physically fixing and locking the FPC to the connector. Actuator is a movable element in an FPC connector, hence to enable effective operation of the actuator, the FPC connector must have a housing structure sufficiently large to physically support the actuator. In applications of compact sized electronic devices, the connectors used in such devices are miniaturized, and the housing of such miniaturized connectors may not have the required dimension, strength and/or rigidity to support an actuator and therefore electrical connection maybe compromised. It is therefore desireable to provide an FPC connector having a compact size and yet is capable to ensure reliable electrical connection with the FPC. 
     SUMMARY OF INVENTION 
     Embodiments of the present invention provide connectors for reliably connecting to an FPC without the need of an actuator. The connector can be made low profile, small and thinner to meet miniaturization requirements for use in compact electronics devices. The FPC can be securely fixed to the connector to establish and maintain electrical connection. 
     In one embodiment, an FPC connector has a housing and contact elements disposed in the housing. The housing has a front end, a back end, a top side, a bottom side and a cavity between the top side and the bottom side. Each contact element has an upper contact arm disposed at the top side and a lower contact arm disposed at the bottom side. The cavity is to receive a circuit board e.g. and FPC therein to establish electrical connection with the upper and lower contact arms. A pair of locking members is attached to the housing. Each locking member has a lock arm positioned along a direction from the back end to the front end of the housing. The upper contact arm and the lower contact arm of each contact element and the lock arm of each locking member are resiliently deflectable away from the cavity to allow insertion of the FPC into the cavity. When the circuit board is inserted into the cavity, the upper contact arm and the lower contact arm are in electrical contact with the FPC, and the lock arm springs back to engage the FPC and lock the circuit board to the housing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the invention are disclosed hereinafter with reference to the drawings, in which: 
         FIG. 1A  is a perspective view showing an FPC connector according to one embodiment of the present invention; 
         FIG. 1B  is a perspective bottom view of  FIG. 1A ; 
         FIG. 2  is an exploded view of  FIG. 1A ; 
         FIG. 3  is a perspective bottom view of the housing of the FPC connector showing in  FIG. 1A ; 
         FIG. 4  is a perspective view showing a contact element of the FPC connector showing in  FIG. 1A ; 
         FIG. 5  is a cross sectional view of  FIG. 1A  along A-A; 
         FIG. 6  is a perspective view showing a locking member of the FPC connector showing in  FIG. 1A ; 
         FIG. 7  is a cross sectional view of  FIG. 1A  along B-B; 
         FIG. 8  is a perspective view showing an FPC to be connected to the FPC connector of  FIG. 1A ; 
         FIG. 9  is a perspective view showing an FPC connected to the FPC connector of  FIG. 1A ; 
         FIG. 10  is a perspective cross sectional view of  FIG. 9  along C-C; 
         FIG. 11  is a perspective cross sectional view of  FIG. 9  along D-D. 
         FIG. 12A  is a perspective view showing an FPC connector according to another embodiment of the present invention; 
         FIG. 12B  is a perspective bottom view of  FIG. 1A ; 
         FIG. 13  is an exploded view of  FIG. 12B ; 
         FIG. 14  is a perspective view showing a contact element of the FPC connector showing in  FIG. 12A ; 
         FIG. 15  is a cross sectional view of  FIG. 12A  along A-A; 
         FIG. 16  is a perspective view showing a locking member of the FPC connector showing in  FIG. 12A ; 
         FIG. 17  is a cross sectional view of  FIG. 12A  along B-B; 
         FIG. 18  is a perspective view showing an FPC to be connected to the FPC connector of  FIG. 12A ; 
         FIG. 19  is a perspective view showing an. FPC connected to the FPC connector of  FIG. 12A ; 
         FIG. 20  is a perspective cross sectional view of  FIG. 19  along C-C; 
         FIG. 21  is a perspective cross sectional view of  FIG. 19  along D-D. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     As shown in  FIG. 1A  and  FIG. 1B , an FPC connector  10  according to one embodiment of the present invention includes a housing  12 , a plurality of contact elements  14 , a pair of locking members  16  and a pair of hold downs  18  attached to housing  12 . Housing  12  is made of molded plastic and has a front side  12   a , back side  12   b , top side  12   c  and bottom side  12   d . Between top side  12   c  and bottom side  12   d  there is formed a cavity  12   e  for receiving an FPC therein to establish electrical connection. 
     As shown in  FIGS. 2 and 3 , housing  12  includes first contact grooves  124  formed at bottom side  12   d  and second contact grooves  126   a  formed on top side  12   c . Formed on top side  12   c  are also fixing grooves  126   b  which extends to back side  12   b  of housing  12 . In addition, hold down grooves  138  and fixing recesses  128   a  are formed on top side  12   c , and fixing holes  128   b  are formed at bottom side  12   d  of housing  12 . 
     As shown in  FIG. 4 , contact element  14  includes a base  140  and a tail  142  extending from base  140  towards a back side of contact element  140 . A lower arm  144  and an upper arm  146  extend from base  140  towards a front side of contact element  140 . Lower arm  144  has a lower contact projection  144   a  formed at a free end thereof, facing upper arm  146 . Upper arm  146  has an upper contact projection  146   a  formed at a free end thereof, facing lower arm  144 . Lower arm  144  and upper arm  146  define a space  145  therebetween for receiving an FPC. A fixing projection  148  is formed on base  140  and extending upwardly from base  140 . 
     To assemble to housing  12 , as shown in  FIG. 5 , each contact elements  14  is inserted and attached to housing  12  from bottom side  12   d  along a direction towards top side  12   c , with fixing projection  148  inserted into fixing recess  128   a . During the insertion process, upper arm  146  passes through first contact groove  124  and cavity  12   e . When fixing projection  148  is fully received in fixing recess  128   a , upper arm  146  is positioned in second contact groove  126   a . Base  140  becomes in contact with first stopper(s)  134  formed in housing  12  hence further insertion of contact element  14  toward top side  12   c  is prevented. Meanwhile, lower arm  144  is received in first contact groove  124  and tail  142  is positioned at back side  12   b  of housing  12 . Contact elements  14  are attached to housing  12  in this manner. Lower arm  144  is elastically deflectable within first contact groove  124 . Likewise, upper arm  146  is elastically deflectable within second contact groove  126   a.    
     As shown in  FIG. 6 , locking member  16  includes a base  160  and a tail  162  extending backwardly and downwardly from base  160 . A locking arm  166  extends forwardly from base  160  and has a catch member  166   a  formed at the free end of locking arm  166 . Formed on base  160  there is a locking projection  168  extending downwardly. 
     To assemble to housing  12 , as shown in  FIG. 7 , each locking member  16  is inserted to housing  12  from top side  12   c  along a direction towards bottom side  12   d , with locking projection  168  inserted into fixing hole  128   b  of housing  12 . When locking projection  168  is fully received in fixing hole  128   b , locking arm  166  is positioned in fixing groove  126   b . Base  160  becomes in contact with second stopper(s)  136  formed in housing  12  hence further insertion of locking member  16  toward bottom side  12   d  is prevented. Meanwhile, tail  162  is positioned at back side  12   b  of housing  12 . Locking members  16  are attached to housing  12  in this manner, and locking arm  166  is allowed to deflect within fixing groove  126   b.    
     In use, as shown in  FIGS. 8 to 11 , an FPC  20  is inserted into cavity  12   e  of housing  12  from front side  12   a  to establish electrical connection with connector  10 . As lower and upper arms  144 ,  146  and locking arm  166  are deflectable due to their elastic characteristics, during the insertion process, FPC  20  will cause lower arm  144  and upper arm  146  to deflect away from each other, hence contact portions  246   a  of FPC  20  can be positioned between lower arm  144  and upper arm  146 , and become electrically connected to lower contact projection  144   a  and upper contact projection  146   a  ( FIG. 10 ). During the insertion process, FPC  20  also pushes catching member  166   a  and causes locking arm  166  of locking member  16  to deflect upwardly. When FPC  20  is at the fully inserted position, as shown in  FIG. 11 , engagement notch  266   a  of FPC  20  is positioned under catching member  166   a  to allow locking arm  166  to resume to original position, such that catching member  166   a  engages FPC  20  at notch  266   a . Disengagement or dropping off of FPC  20  from connector  10  can therefore be prevented. 
     As shown  FIG. 12A, 12B and 13 , an FPC connector  30  according to another embodiment of the present invention includes a housing  32 , a plurality of contact elements  34 , a pair of locking members  36  and a pair of hold downs  38  attached to housing  32 . Housing  32  is made of molded plastic and has a front end  32   a , back end  32   b , top side  32   c  and bottom side  32   d . Between top side  32   c  and bottom side  32   d  there is formed a cavity  32   e  for receiving an FPC therein to establish electrical connection with contact elements  34 . 
     Housing  32  includes first contact grooves  324   a  and first fixing grooves  326   a  formed at bottom side  32   d . Housing  32  also includes second contact grooves  324   b  and second fixing grooves  326   b  formed on top side  32   c . Fixing holes  328  are formed in housing  32  from top side  32   c  through bottom side  32   d.    
     As shown in  FIG. 14 , contact element  34  has a base  340  and a tail  342  extending from base  340  toward a back side (right side in  FIG. 14 ) of contact element  340 . A lower arm  344  and an upper arm  346  extend from base  340  toward a front side (left side in  FIG. 14 ) of contact element  34 . Lower arm  344  has a lower contact projection  344   a  formed at a free end thereof, facing upper arm  346 . Upper arm  346  has an upper contact projection  346   a  formed at a free end thereof, facing lower arm  344 . Lower arm  344  and upper arm  346  form a space  345  therebetween, for receiving an FPC. A fixing projection  348  is formed on base  340  and extending upwardly from base  340 . 
     To assemble to housing  32 , as shown in  FIG. 15 , each contact element  34  is inserted and attached to housing  32  from bottom side  32   d  towards top side  32   c , with fixing projection  348  inserted into fixing hole  328 . During the insertion process, upper arm  346  passes through first contact groove  324   a  and cavity  32   e . When fixing projection  348  is fully received in fixing hole  328 , upper arm  346  is positioned in second contact groove  326   b . Meanwhile, lower arm  344  is received in first contact groove  324  and tail  342  is positioned at back side  32   b  of housing  32 . Base  340  becomes in contact with first stopper(s)  334  formed in housing  32 , hence further movement of contact element  34  toward top side  32   c  is prevented. Lower arm  344  is elastically deflectable within first contact groove  324   a . Likewise, upper arm  346  is elastically deflectable within second contact groove  324   b.    
     As shown in  FIG. 16 , locking member  36  includes a base  360  and a tail  362  extending backwardly from base  360 . A locking arm  366  extends forwardly from base  360 , and is offset from base  360  along a direction perpendicular to base  360 . Locking arm  366  has a catch member  366   a  formed at the free end of locking arm  366 , and faces downward. A locking projection  368  extends upwardly from base  360 . The front end of locking arm  366  may be tapered, e.g. at a downward angle α. 
     To assemble to housing  34 , as shown in  FIG. 17 , each locking member  36  is inserted into housing  32  from bottom side  32   d  along a direction towards top side  32   c , with locking arm  366  passing through first fixing groove  326   a , and locking projection  368  inserted into fixing hole  328  of housing  32 . When locking projection  368  is fully received in fixing hole  328 , locking arm  366  is positioned in second fixing groove  326   b  at top side of housing  32 . At this position, catch member  366   a  is disposed in cavity  32   e  and faces downward. Base  360  becomes in contact with second stoppers  336  formed in housing  32 , hence further insertion of locking member  36  toward top side  32   c  of housing  32  is prevented. Meanwhile, tail  362  is positioned at back side  32   b  of housing  32 . Locking members  36  are attached to housing  32  in this manner, and locking arm  366  is allowed to deflect within second fixing groove  326   b.    
     In use, as shown in  FIGS. 18 to 21 , an FPC  40  is inserted into cavity  32   e  of housing  32  from front side  32   a  to establish electrical connection with connector  30 . As lower and upper arms  344 ,  346  and locking arm  366  are deflectable due to their elastic characteristics, during the insertion process, FPC  40  will cause lower arm  344  and upper arm  346  to deflect away from each other, hence contact portions  346   a  of FPC  40  can be positioned between lower arm  344  and upper arm  346 , and is electrically connected to lower contact projection  344   a  and upper contact projection  346   a  ( FIG. 20 ). 
     During the insertion process, FPC  40  also acts against catching member  366   a  and causes locking arm  366  of locking member  36  to deflect upwardly. As second stoppers  336  acts against base  360  of locking arm  36 , upward-deflection of locking arm  366  will have a tendency to tighten the attachment of locking member  36  to housing  32 . As such, movement of locking member  36  relative to housing  32 , and/or detachment of locking member  36  from housing  32  during the insertion process of FPC to connector  30 , is prevented. 
     When FPC  40  is at the fully inserted position, as shown in  FIG. 21 , engagement notch  466   a  of FPC  40  is positioned under catching member  366   a  to allow locking arm  366  to resume to original position, such that catching member  366   a  engages FPC  40  at notch  466   a . Disengagement or dropping off of FPC  40  from connector  30  can therefore be prevented and hence the electrical connection between FPC  40  and connector  30  is ensured. 
     Although embodiments of the present invention have been illustrated in conjunction with the accompanying drawings and described in the foregoing detailed description, it should be appreciated that the present invention is not limited to the embodiments disclosed. Therefore, the present invention should be understood to be capable of numerous rearrangements, modifications, alternatives and substitutions without departing from the spirit of the invention as set forth and recited by the following claims.