Abstract:
An electrical connector is provided for terminating a flat electrical circuit. The connector includes a dielectric housing having an opening for receiving an end of the flat circuit. A plurality of signal terminals are mounted on the housing along the opening and include contact portions for engaging signal conductors on the flat circuit. At least one ground terminal is mounted on the housing and includes a contact portion for engaging a ground conductor on the flat circuit. An actuator is movably mounted on the housing for movement between an open position allowing the end of the flat circuit to be inserted into the opening and a closed position relatively biasing the flat circuit against the contact portions of the signal terminals. A guide member is movably mounted on the housing independent of the actuator and for movement between an open position allowing the end of the flat circuit to be inserted into the opening and a closed position relatively biasing the flat circuit against the contact portion of the ground terminal.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention generally relates to the art of electrical connectors and, particularly, to a connector for terminating a flat circuit, such as a flat flexible circuit, a flexible printed circuit or other flat electrical cable.  
       BACKGROUND OF THE INVENTION  
       [0002]     A wide variety of electrical connectors have been designed for terminating flat cables or circuits, such as flat flexible cables, flexible printed circuits or the like. A typical connector for flat circuits includes a dielectric housing molded of plastic material, for instance. The housing has an elongated opening or slot for receiving an end of the flat circuit which has generally parallel, laterally spaced conductors exposed across the end. A plurality of terminals are mounted in the housing and are spaced laterally along the slot, with contact portions of the terminals engageable with the laterally spaced conductors of the flat circuit. An actuator often is movably mounted on the housing for movement between a first position whereat the flat circuit is freely insertable into the slot and a second position whereat the actuator clamps the circuit in the housing and biases the circuit against the contact portions of the terminals. An example of these types of connectors is shown in Japanese Patent Application Laid-Open No. 2004-87361.  
         [0003]      FIG. 1  shows a sectional view through a flat circuit connector of the prior art. The connector includes a housing, generally designated  10 , having an insertion opening  12  for allowing insertion of a flat circuit, such as a flexible printed circuit, into the connector. A plurality of conductive terminals, generally designated  14 , are mounted on the housing and are arranged in a spaced array along the opening. Each terminal has a contact portion  14   a  extending into the opening for engaging a conductor on a face of the flat circuit. An actuator, generally designated  16 , is pivotally mounted on the connector for rotation from an open position (shown in phantom) allowing the end of the flat circuit to be inserted into opening  12  and a closed position (shown in full lines) whereat a pressing portion  16   a  of the actuator biases the flat circuit against the contact portions  14   a  of terminals  14  and prevents removal of the circuit. Signal conductors on the surface of the flat circuit are pressed against the contact portions of the terminals to connect the flat circuit to a printed circuit board through tail portions  14   b  of the terminals.  
         [0004]     With the prior art connector of  FIG. 1 , actuator  16  presses the flat circuit against contact portions  14   a  of the terminals only at a single location with respect to the insertion direction of the flat circuit. Therefore, if the flat circuit has ground conductors, exposed portions of the ground conductors and the exposed portions of the signal conductors are located at different positions with respect to the insertion direction of the flat circuit. As a result, actuators such as actuator  16 , cannot press the ground conductors against any ground terminals. The present invention is directed to solving these problems in a flat circuit connector which includes both ground terminals and signal terminals.  
       SUMMARY OF THE INVENTION  
       [0005]     An object, therefore, of the invention is to provide a new and improved flat circuit connector of the character described.  
         [0006]     In the exemplary embodiment of the invention, an electrical connector is provided for terminating a flat electrical circuit. The connector includes a dielectric housing having an opening for receiving an end of the flat circuit. A plurality of signal terminals are mounted on the housing along the opening and include contact portions for engaging signal conductors on the flat circuit. At least one ground terminal is mounted on the housing and includes a contact portion for engaging a ground conductor on the flat circuit. An actuator is movably mounted on the housing for movement between an open position allowing the end of the flat circuit to be inserted into the opening and a closed position relatively biasing the flat circuit against the contact portions of the signal terminals. A guide member is movably mounted on the housing independent of the actuator and for movement between an open position allowing the end of the flat circuit to be inserted into the opening and a closed position relatively biasing the flat circuit against the contact portion of the ground terminal.  
         [0007]     According to one aspect of the invention, the actuator is mounted on the housing for pivotal movement between its open and closed positions. The guide member is mounted on the housing for sliding movement between its open and closed positions. The actuator has a pressing portion for engaging the flat circuit and biasing the circuit against the contact portions of the signal terminals. The guide member has a pressing portion for engaging the flat circuit and biasing the circuit against the contact portion of the ground terminal.  
         [0008]     According to another aspect of the invention, the guide member is mounted on the housing closer to a mouth of the opening than the actuator, whereby the guide member guides the flat circuit into the opening. The contact portion of the ground terminal is located nearer to the mouth of the opening than the contact portions of the signal terminals.  
         [0009]     According to a further aspect of the invention, the guide member is interengaged with the actuator for conjoint movement therewith. The actuator has a cam portion for engaging and moving the guide member from its open to its closed position automatically in response to the actuator moving from its open to its closed position.  
         [0010]     Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the figures and in which:  
         [0012]      FIG. 1  is a sectional view through the prior art connector as described in the Background, above;  
         [0013]      FIG. 2  is a front perspective view of a flat circuit connector according to the invention;  
         [0014]      FIG. 3  is a rear perspective view of the connector;  
         [0015]     FIGS.  4 ( a ), ( b ) and ( c ) are front elevational, top plan and side elevational views, respectively, of the connector;  
         [0016]     FIGS.  5 ( a ) and ( b ) are perspective views showing the assembly of the guide member to the connector housing;  
         [0017]     FIGS.  6 ( a ) and ( b ) are perspective views showing the assembly of the actuator to the connector housing;  
         [0018]      FIG. 7  is a front-to-rear section, on an enlarged scale, showing both the actuator and the guide member in their respective open positions;  
         [0019]      FIG. 8  is a view similar to that of  FIG. 7 , but taken at a location longitudinally of the connector from the location of  FIG. 7 ; and  
         [0020]      FIG. 9  is a view similar to that of  FIG. 7 , but with the actuator and the guide member in their respective closed or terminating positions.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0021]     Referring to the drawings in greater detail, and first to  FIGS. 2-4 , the invention is embodied in a flat circuit connector, generally designated  10 . The connector can terminate various flat circuits, such as a flat flexible circuit, a flexible printed circuit or other flat electrical cables. Generally, connector  10  includes a dielectric housing, generally designated  12 ; a plurality of signal terminals  14  ( FIG. 4 ) mounted on the housing; a plurality of ground terminals  16  mounted on the housing; an actuator, generally designated  18 , pivotally mounted on the housing; and a guide member, generally designated  20 , slidably mounted on the housing. In addition, a pair of fitting nails  22  are mounted on the housing at opposite ends thereof for fixing the housing to a printed circuit board.  
         [0022]     At this point, it should be understood such terms as “front”, “rear”, “top”, “bottom”, “up”, “down”, and the like herein and in the claims hereof are not intended in any way to be limiting. Such terms are used solely for providing a clear and concise understanding of the invention as viewed in the drawings, the connector being omni-directional in both use and function. For instance,  FIGS. 2-4  show connector  10  mounted in a vertical orientation for securement on top of a printed circuit board. Therefore, fitting nails  22  have tails portions  22   a  at the bottoms thereof for securement, as by soldering, to appropriate mounting pads on the printed circuit board (not shown).  
         [0023]     With those understandings, housing  12  of connector  10  is elongated and includes an opening, generally designated  24 , which runs longitudinally of the housing for receiving an end of a flat circuit. The opening opens at the top of the connector whereby the flat circuit is inserted downwardly into the opening. The housing is a one-piece structure which may be molded of dielectric material such as plastic or the like. The housing has a front portion  12   a , a rear portion  12   b  and opposite end portions  12   c , all of which combine to define elongated opening  24 . A plurality of terminal-receiving grooves  26  are formed in the housing at spaced intervals along opening  24  for receiving signal terminals  14 . In the illustrated embodiment, approximately twenty terminal-receiving grooves  26  are formed at a pitch of, for example, approximately 0.5 mm, and a single signal terminal  26  is inserted into each groove. However, it should be understood that signal terminals are not necessarily received in all of the grooves, because some of the signal terminals can be omitted depending upon the arrangement of the signal conductors on the flat circuit.  
         [0024]     Each signal terminal  14  has a tail portion  14   a  which extends rearwardly at the bottom of the housing as seen in  FIG. 4 ( c ) for connection to an appropriate signal circuit trace on the printed circuit board. Ground terminals  16  have tail portions  16   a  which project forwardly at the bottom of the connector for connection to appropriate ground traces on the printed circuit board. Tail portions  14   a  of signal terminals  14 , tail portions  16   a  of ground terminals  16  and tail portions  22   a  of fitting nails  22  all are coplanar for connection, as by soldering, to the flat surface of the printed circuit board. As seen best in  FIG. 2 , each fitting nail  22  has an upwardly projecting spring arm  22   b  which has a rearwardly projecting detent protrusion  22   c  at the free distal end thereof. The spring arm forms a cantilever member.  
         [0025]     Ground terminals  16  are mounted in grooves  28  ( FIG. 2 ) between partitions  30  at front portion  12   c  of the housing. Referring to  FIGS. 7-9 , it can be seen that each ground terminal  16  has an inverted U-shaped configuration at the top thereof, whereby a contact portion  16   b  is bent back downwardly into opening  24  for engaging a respective ground conductor on a front face of a flat circuit  32  as shown in  FIG. 9 . In comparing  FIGS. 8 and 9 , the main body portion of each ground terminal acts as a cantilever member which can move in the direction of double-headed arrow “A” as the bottom of the main body portion is fixed within a slit  34  of the housing. As seen best in  FIG. 2 , the particular configuration of connector  10  includes five ground terminals  16  at regularly spaced intervals, such as a pitch of approximately 5 mm. However, the number and spacing of the ground terminals can be changed according to the particular configuration of the ground conductors on flat circuit  32 . The ground terminals may be stamped and formed of conductive sheet metal material.  
         [0026]     Referring to  FIGS. 7 and 8 , signal terminals  14  have two different configurations  14 A and  14 B and which alternate longitudinally along elongated opening  24 . All of the signal terminals have tail portions  14   a  for connection to the signal traces on the printed circuit board, as described above. All of the signal terminals have body portions  14   b  which fix the terminals within a plurality of terminal-receiving passages  34  in housing  12 . All of the signal terminals have upwardly extending contact arms which have contact portions  14   d  at the free distal ends thereof. Contact portions  14   d  are exposed within opening  24  for engaging appropriate signal conductors on flat circuit  32  as seen in  FIG. 9 . However, signal terminals  14 A differ from signal terminals  14 B in that signal terminals  14 A have upwardly projecting pivot arms  14   e  ( FIG. 7 ) which are L-shaped to define pivot sockets  14   f  for purposes described hereinafter. On the other hand, signal terminals  14 B have straight upwardly projecting detent arms  14   g  ( FIG. 8 ) which have detent notches  14   h  for purposes described hereinafter.  
         [0027]     As best seen in  FIG. 5 ( a ), guide member  20  has an elongated body portion  20   a  and opposite end portions  20   b  which extend forwardly of the body portion. A pressing portion or rib  20   c  projects forwardly along the bottom edge of the body portion in front of a recessed area  20   d  of the body portion. An engagement block  20   e  projects longitudinally inwardly from each end portion  20   b  of the guide member. The distance between the inside surfaces of engagement blocks  20   e  is substantially equal to the distance between the outside surfaces of end portions  12   c  of housing  12 . Still referring to  FIG. 5 ( a ), housing  12  has a vertically extending guide rib  38 , a horizontally extending stop rib  40  and a horizontal detent rib  42 , all of which project outwardly of the end face of each end portion  12   c  of the housing. Detent ribs  42  do not project outwardly as far as guide ribs  38  and stop ribs  40 .  
         [0028]     Guide member  20  is assembled to housing  12  in the direction of arrow “B” as seen in  FIG. 5 ( a ). During assembly, engagement blocks  20   e  of the guide member ride along the outside surfaces of end portions  12   c  of the housing. Once the guide member reaches its limit of movement, the guide member then is moved upwardly relative to the housing in the direction of arrow “C” as seen in  FIG. 5 ( b ). During upward movement of the guide member, engagement blocks  20   e  move upwardly along the front of the vertically extending guide ribs  38  on the housing until the engagement blocks abut against the horizontally extending stop ribs  40 . The engagement blocks ride over horizontal detent ribs  42  until the engagement blocks “snap” into position above the detent ribs as the detent ribs hold the guide member in its upper limit position as seen in  FIG. 5 ( b ).  
         [0029]     Actuator  18  has an elongated main body portion  18   a  and opposite end portions  18   b . The opposite end portions also have cam portions  18   c . As best seen in  FIG. 7 , the actuator has a plurality of spaced slots  18   d  for accommodating pivot arms  14   e  of signal terminals  14 A. As seen in  FIG. 8 , the actuator also has a plurality of passages or slots  18   e  for accommodating detent arms  14   g  of signal terminals  14 B. As with the two different configurations of signal terminals, slots  18   d  and passages  18   e  alternate longitudinally of the actuator. The actuator has pivot pins  44  ( FIG. 7 ) which span slots  18   d  and which seat within pivot sockets  14   f  of pivot arms  14   e . The actuator also has detent corners  46  ( FIG. 8 ) which seat within detent notches  14   h  of detent arms  14   g  of terminals  14 B. Finally, actuator  18  has a pressing portion  18   g  for pressing flat circuit  32  into engagement with contact portions  14   d  of the signal terminals. Actuator  18  is assembled to housing  12  in the direction of arrow “D” as seen in  FIG. 6 ( a ). The actuator is assembled sort of in a horizontal orientation until the actuator reaches a position as shown in  FIG. 6 ( b ).  
         [0030]     It can be seen in FIGS.  6 ( a ) and  6 ( b ) that signal terminals  14 A already are assembled to housing  12  before actuator  18  is assembled. This allows pivot pins  44  ( FIG. 7 ) of the actuator to move into pivot sockets  14   f  of pivot arms  14   e  of signal terminals  14 A.  
         [0031]     The sequence of assembling flat circuit connector  10  now will be described. Specifically, guide member  20  is assembled to housing  12  as shown in FIGS.  5 ( a ) and ( b ) and as described above. It can be seen in those views that none of the terminals have as yet been mounted on the housing. As described above, the guide member is moved to its temporarily held position of  FIG. 5 ( b ).  
         [0032]     Signal terminals  14 A ( FIG. 7 ) then are assembled to the housing in the direction of arrow “E” as body portions  14   b  of the terminals are inserted into the terminal-receiving passages  34  of the housing. At this point, terminals  14 B are not inserted into the housing because detent arms  14   g  of the terminals would block assembly of actuator  18 .  
         [0033]     The actuator then is assembled to housing  12  as shown in FIGS.  6 ( a ) and ( b ) and as described above. The actuator is inserted until pivot pins  44  ( FIG. 7 ) seat within pivot sockets  14   f  of signal terminals  14 A. When fully inserted, the actuator is pivoted upwardly to its open position as shown in  FIGS. 7 and 8 , whereupon signal terminals  14 B ( FIG. 8 ) can be inserted into the housing in the direction of arrow “F” ( FIG. 8 ).  
         [0034]     Actuator  18  is held in its open position of  FIGS. 7 and 8  by two distinct means. First, as seen in  FIG. 8 , the actuator is held in its open position by detent corners  46  of the actuator being disposed within detent notches  14   h  of signal terminals  14 B. Second, as seen best in  FIGS. 2-4 , cam portions  18   c  at opposite ends of the actuator are disposed beneath detent projections  22   c  at the top ends of the cantilevered spring arms  22   b  of fitting nails  22 . In the open position of the actuator, flat circuit  32  can be inserted freely into opening  24  of the housing.  
         [0035]     Ground terminals  16  can be assembled to the housing practically at any time, but it most likely would be easiest to assemble the ground terminals after the guide member, the actuator and all of the signal terminals have been assembled. In any event, after actuator  18  has been assembled and temporarily held in its open position as described above, guide member  20  can be pushed downwardly in the direction of arrow “G” ( FIG. 7 ) until a bottom inclined surface  20   f  of the guide member interengages with the top of actuator  18  as seen in  FIGS. 7 and 8 . The guide member is pushed downwardly from its temporarily held position shown in  FIG. 5 ( b ) simply by overriding horizontal detent ribs  42  on the outside faces of the end portions  12   c  of the housing. The guide member now is in its open position shown in  FIGS. 7 and 8 , allowing flat circuit  32  to be inserted freely into opening  24  of the housing. It can be seen that there is considerable spacing between pressing portion  20   c  of the guide member and the opposite side opening  24  for the flat circuit to be inserted freely into the opening.  
         [0036]     After flat circuit  32  is inserted into the connector in the direction of arrow “H” ( FIG. 9 ), actuator  18  is pivoted downwardly in the direction of arrow “I” to its closed position whereat pressing portion  18   g  of the actuator biases flat circuit  32  and its signal conductors into engagement with contact portions  14   d  of signal terminals  14  ( 14 A and  14 B).  
         [0037]     Generally, actuator  18  is effective to automatically move guide member  20  from its open position to its closed position as the actuator is pivoted to its closed position. Specifically, cam portions  18   c  at opposite ends of the actuator engage the undersides of end portions  20   b  of the guide member and push the guide member from the dotted line position shown in  FIG. 9  to the full-line position of the guide member. The guide member effectively biases flat circuit  32  and its ground conductors into engagement with contact portions  16   b  of ground conductors  16 , the contact portions projecting into opening  24 .  
         [0038]     It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.