Patent Publication Number: US-6908335-B1

Title: Connector for a flexible printed circuit board

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to a connector, it relates specifically a connector, which can effectively prevent Flexible Printed Circuit Board (abbreviated as FPCB) from getting loose. 
   2. Description of the Related Art 
   Printed circuit board is an indispensable basic component for electronic product, it needs to possess flexible characteristics when it is used in circuit where “moving function” is necessary, therefore, flexible printed circuit board with light weight and small form factor has been invented for this industry, it allows three dimensional circuit layout possible due to limited space and size in the product, therefore, electronic, communication or military application, where light weight, thin profile, and small size are important, will need FPCB. 
   Since FPCB is of light weight and thin and flexible, therefore, when it is used in the connection in electronic circuit, as shown in  FIG. 1 , the connection end of FPCB  1 ′ has to be connected by connector  2 ′ in order to enhance its mechanical strength, on the main body of connector  2 ′ is installed with slot  21 ′ for the fixing of terminal  22 ′, furthermore, FPCB  1 ′ is inserted into slot  21 ′, a locking part  23 ′ is used to form a close contact between FPCB  1 ′ and the contact arm  221 ′ of terminal  22 ′, terminal  22 ′ further forms connection between flexible printed circuit  1 ′ and the electronic circuit designed and installed in connector  2 ′. Moreover, when FPCB  1 ′ operates and moves along with the electronic circuit it is connected to, certain degree of teasing and pulling actions are going to appear between FPCB  1 ′ and connector  2 ′ and the connection could thus gets loose; therefore, the terminal  22 ′ of connector  2 ′ is a structure comprising a protruding part  222 ′ located at the contact side of its contact arm  221 ′ which is in contact with FPCB  1 ′, this structure allows FPCB  1 ′ to be inserted in between contact arm  221 ′ and locking part  23 ′ when the locking part  23 ′ of connector  2 ′ has not been locked toward contact arm  221 ′, furthermore, contact arm  221 ′ can generate an elastic distortion when the locking part  23 ′ compresses and locks toward contact arm  221 ′ such that locking part  23 ′ can compresses, locks and positions, the elastic force from the contact arm  221 ′ can force protruding part  222 ′ compresses to ward FPCB  1 ′ in order to increase the combining strength between FPCB  1 ′ and terminal  22 ′. 
   Nevertheless, in the prior art connector  2 ′, the supporting arm  223 ′ of terminal  22 ′ forms a pivoting and limiting action on the locking part, although the protruding part  222 ′ of the contact arm  221 ′ of the terminal  22 ′ can form a compression action on the FPCB  1 ′ when locking part  23 ′ is completely locked and compressed, but this compression action comprising of only the spring force coming from contact arm  221 ′, this seems to be not enough to hold tight the FPCB  1 ′, moreover, the elastic force of contact arm  221 ′ will decay with time, the compression force between contact arm  221 ′ and FPCB  1 ′ will then be reduced, bad connection can thus happen unpredictably between FPCB  1 ′ and the electronic circuit, or FPCB  1 ′ can even get loose. 
   SUMMARY OF THE INVENTION 
   This invention aims at improving the drawbacks of the prior art connector and it fits the real application demand, a connector to be applied in the flexible printed circuit is invented for industrial application. 
   Technical means is adopted in this invention, a supporting arm which extends into the slot is installed at the base of the terminal, furthermore, at both ends of the locking part are installed with pivoting parts to be connected to the main body of the connector, in the mean time, through hole is installed at the corresponding location to the supporting arm of the terminal, the inner wall of the through hole is a pivoting and rotating part which is of floating and protruding shape, moreover, the front end of the supporting arm of the terminal is installed with a curved and through-hole-penetrating elastic compression part and a dented part accompanied with a pivoting part, therefore, when the locking part is in action, the pivoting and rotating part of locking part face directly the dented part of supporting arm, it allows the curved elastic compression part and dented part in the front end of supporting arm to form a tight compression and liming action such that bouncing away of locking part can be well prevented and in turn it can further prevent FPCB from getting loose, this is the main purpose of the current invention. 
   Yet another purpose of the current invention, the terminal structure comprising of a slot which can be inserted into a connector to be connected to FPCB, moreover, a guiding arm is installed at the front end of the contact arm of the terminal, first protruding part and second protruding part installed at the guiding arm and of fixed length are protruding toward FPCB and the inner wall of slot, respectively, through the guiding action of the guiding arm, it can lead FPCB to enter correctly the space between contact arm and the locking part, therefore, when the locking part locks, locking part compresses and positions by using the elastic distortion of contact arm and guiding arm, moreover, when the locking part locks completely, the first protruding part of the guiding arm can compress and hold tight FPCB, moreover, the second protruding part and the inner wall of slot can touch each other and form a supporting function ,this supporting function can limit the distortion of guiding arm in the reverse direction, therefore, the compression action put on FPCB by first protruding part can be maintained, and the combination strength between FPCB and terminal can be greatly enhanced, a loose connection of FPCB can thus be prevented. 
   Yet another purpose of the current invention, spring piece can be installed further at the slot of the connector, spring piece and the pivoting part of the locking part compresses to each other, in the mean time, protruding and dented lock which can hold and lock to each other when the locking part locks completely are installed at the contact location between the spring piece and the pivoting part, dented lock and protruding lock can further enhance the limiting function of the locking part, therefore, when the elastic distortion force of the contact arm and supporting arm of terminal disappears, locking part won&#39;t bounce away before it receives a reverse action force, locking part can still form a stable and tight compression between FPCB and terminal. 
   Further another purpose of the current invention, between the arm surface of the guiding arm and the wall of slot, a buffer zone is formed, when a thicker FPCB is inserted, it not only causes elastic distortion at the contact arm, but also causes a second elastic distortion at the buffer zone of contact arm, therefore, bouncing away or breaking of locking part can be prevented. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a flexible printed circuit board is inserted in the prior art connector. 
       FIG. 2  shows the appearance of the connector for the current invention. 
       FIG. 3  shows a flexible printed circuit board is inserted in the connector of the current invention. 
       FIG. 4  shows a flexible printed circuit board is inserted and locked in the connector of the current invention. 
       FIG. 5  shows an assembly relationship between the locking part and spring piece of the connector of the current invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Please refer to  FIGS. 2 and 3 , the connector of the current invention is installed with a slot  21  on its main body  2 , terminal  3  is installed and fixed inside slot  21  such that FPCB  1  can be inserted into slot  21  to be connected to terminal  3 , and a locking part  4  which can compress terminal  3  and FPCB  1  is installed at one side of slot  21 , it is used to increase the combination strength between FPCB  1  and terminal  3 . 
   The above-mentioned terminal  3  has a base  31  which is installed with fixed length contact arm  32  and supporting arm  33  which are further inserted in the slot  21  of connector  2 , the front end of the supporting arm  33  is installed with curved and through-hole-penetrating elastic compression part  331  and a dented part  332  accompanied with a pivoting part, furthermore, a guiding arm  34  is installed in the front end of the contact arm  32 , first protruding part  341  and second protruding part  342  installed at the guiding arm  34  and of fixed length are protruding toward FPCB  1  and the inner wall of slot  21  respectively, guiding arm  34  can guide FPCB  1  to move correctly into the space between contact arm  32  and locking part  22 , moreover between the arm surface of the guiding arm  33  and the wall of slot  21 , a buffer zone is formed ,when a thicker FPCB  1  is inserted, it not only causes elastic distortion at the contact arm  32 , but also causes a second elastic distortion at the buffer zone of contact arm  33 , therefore, bouncing away or breaking of locking part  22  can be prevented. 
   The above-mentioned locking part  4  has pivoting part  41  installed at both ends of it in order to be connected to the main body  2  of the connector, in addition, through hole  42  is installed at the corresponding location to the supporting arm  33  of terminal  3 , the inner wall of through hole  42  is a pivoting and rotating part  43  which is protruding and floating. 
   Therefore, as shown in  FIG. 4 , when the locking part  4  is in action, the pivoting and rotating part  43  of locking part  4  face directly the dented part  332  of supporting arm  33 , furthermore, locking part  4  compresses and positions by using the elastic distortion of contact arm  32  and guiding arm  34  of terminal  3 , moreover, when the locking part  4  locks completely, it allows the curved elastic compression part  331  and dented part  332  in the front end of supporting arm  33  to form a tight compression and liming action such that bouncing away of locking part  4  can be well prevented and in turn it can further prevent FPCB from getting loose, in the mean time , the first protruding part  341  of the guiding arm  34  can compress and hold tight FPCB  1 , moreover, the second protruding part  342  and the inner wall of slot  21  can touch each other and form a supporting function, this supporting function can limit the distortion of guiding arm  34  in the reverse direction, therefore, the compression action put on FPCB  1  by first protruding part  341  can be maintained ,and the combination strength between FPCB  1  and terminal  3  can be greatly enhanced , a loose connection of FPCB  1  can thus be prevented. 
   Further as shown in  FIG. 5 , spring piece  5  is installed additionally in the slot  21  of the connector of the current invention, spring piece  5  compress to the pivoting part  41  of the locking part  4 , dented lock  51  and protruding lock  411  which can lock and hold to each other after locking pail  4  performs its locking action are installed at the contact location of spring piece  5  and pivoting part  41 , dented lock  51  and protruding lock  411  further enhances the limiting action of locking part  4 , therefore, when the elastic distortion force of the contact arm  32  and supporting arm  33  of terminal  3  disappears, locking part  2  won&#39;t bounce away before it receives a reverse action force, locking part  2  can still form a stable and tight compression between FPCB  1  and terminal  3 . 
   Summarize the above descriptions, the connector provided by this invention can not only greatly enhance the combination strength of FPCB  1 , but also remain the expected connection between FPCB  1  and electronic circuit, it can further prevent a loose connection of FPCB  1  when it moves frequently along with the electronic circuit it is connected to, this invention is of great industry utility value.