Abstract:
A low profile flat printed circuit connector has a plurality of terminals supported along a support bar. The terminals are spaced apart from each other and extend lengthwise in a connector housing. The terminals have body portions that engage the support bar and body portions that extend forwardly thereof. Contact portions are joined to the body portions and extend rearwardly and terminate in free ends so that they form a series of cantilevered contacts.

Description:
BACKGROUND OF THE INVENTION 
     The present invention generally relates to a connector for connecting a length of flexible printed circuitry to an array of conductive terminals. 
     In order to provide an electrical connection between flat flexible circuit cable, known as flexible printed circuit (FPC) or flexible flat cable (FFC) and terminals, FPC/FFC cables are known, such as that shown in Japanese Patent Application Laid-Open Application (Kokai) No. 10-116659.  FIG. 8  is a cross-sectional view of a conventional cable connector. 
     The conventional connector has a insulative housing  301  with a plurality of terminal holding spaces  302  partitioned by partitioning walls  307 , and a plurality of terminals  303  that are formed of a conductive material such as metal, and are held within the terminal holding spaces  302 . The terminals  303  have a U-shaped cross section, with solder tail parts  308  that are connected by soldering to conductive traces on a substrate  311 . 
     The housing  301  is provided with a cable inserting space  309  that spatially connects transversely the upper side of the respective terminal holding spaces  302 . The tip of the flat cable  310  inserted from the inserting hole  305  is then inserted into the cable inserting space  309 . Each of the terminals  303  has an upper piece  304  that extends upwardly, to make resilient contact with a corresponding lead on the cable  310  inserted into the inserting space  309 . The housing  301  has a guide  306  extending obliquely upward from a lower part thereof. The guide  306  covers the area on the side on which the inserting holes  305  of the terminals  303  are disposed, in order that the tips of the flat cables  310  inserted from the inserting holes  305  are guided into the inserting spaces  309 . 
     Nevertheless, in the above conventional cable connector, the U-shape cross section of the terminals  303  increases the vertical dimension, resulting in an increase in the total thickness of the cable connector. Further, guiding the tips of the flat cables  310  into the inserting spaces  309  requires the guide  306  to cover the area on the side on which the inserting holes  305  of the terminals  303  are disposed. This complicates the shape of the housing  301 . In addition, the terminal holding spaces  302  are required for holding the respective terminals  303  and these spaces further complicates the shape of the housing  301 . 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a flat cable connector that overcomes the aforementioned disadvantages and which maintains a low vertical profile. It is therefore an object of the present invention to provide a cable connector and a terminal therefor that permits easy insertion of a flat cable, and permits a reliable connection of the flat cable without causing disengagement thereof from the terminal, with a thin and simple structure while providing the terminal with such an improved configuration such that a front end portion and a rear end portion are arranged to be firmly secured to a substrate, and a free end arranged to be movable in a vertical direction with respect to a surface of the substrate, is disposed between the front end portion and the rear end portion. 
     To this end, in accordance with one aspect of the present invention, the terminals of the connectors of the invention are adapted for insertion into a cable connector mounted to a surface of a substrate, and for connection to the leads of a flat cable inserted into the connector. The terminal is configured such that a free end thereof extends in an insertion direction of the cable (rearwardly of the connector), and has front and rear end portions that are firmly secured to the surface of the substrate, so that the free end is movable vertically with respect to the surface of the substrate, and is positioned between the front end portion and the rear end portion. 
     In accordance with another aspect of the present invention, the connector terminal is further provided with a contact part capable of contacting the flat cable leads and extends in the insertion direction, one end of the contact part being connected to the front end portion, and the other end being the free end. 
     In accordance with one aspect of the present invention, there is provided a cable connector provided with: a body part extending in an insertion direction of a flat cable connected, one end of the body part being connected to a rear end portion; a connecting part extending in the insertion direction, one end of which is connected to the body part, and the other end is connected to a front end portion; and a plurality of terminals, each having a contact part making a contact with a lead of the flat cable, one end of the contact part being connected to the rear end portion, and the other end being a free end. The terminals of the cable connector are provided with a lateral frame part for fixing the body part, and are arranged in parallel to the insertion direction by a terminal supporting member formed of an insulating material. 
     In accordance with another aspect of the present invention, the connector is configured so that the terminal contact is resilient and is displaced away from the surface of the substrate, when the connector does not have a flat cable inserted thereinto, and is disposed parallel with the connecting part. The contact part and the connecting part and the front end portion of the cable connector are formed integrally on an identical side of the surface of the substrate. 
     In accordance with a still other aspect of the present invention, there is provided a cable connector configured such that the terminal housing portion thereof includes a pair of holding arm parts that are connected to both ends of a connector base and and extend in the insertion direction. 
     In accordance with a still other aspect of the present invention, there is provided a cable connector configured with a pair of retaining arms that engages ear, or tab portions on the housing to retain the flat cable in place therein. 
     In accordance with a still other aspect of the present invention, the cable connector is provided with a cover member secured to the surface of the substrate so as to cover the terminals and the terminal supporting member, and configured to define an inserting hole between the cover member and the surface of the substrate so as to permit insertion of a flat cable therein. 
     In accordance with the present invention, a cable connector includes a terminal having a front end portion and a rear end portion which are firmly fixed to a substrate, and further having a free end that is movable in a vertical direction with respect to the surface of the substrate, the free end being disposed between the front end portion and the rear end portion. Hence, the cable connector can be thin and simple structure while permitting an easy insertion of the flat cable without causing abutment of the front end portion of the terminal against the flat cable, and also permitting a reliable connection of the flat cable without causing disengagement thereof from the terminal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       During the course of this detailed description, reference will be frequently made to the drawings wherein like parts are represented by like reference numbers and in which: 
         FIG. 1  is a perspective view showing a terminal assembly used in cable connectors constructed in accordance with the principles of the present invention; 
         FIG. 2  is an exploded view of a cable connector of the present invention with its cover removed for clarity and with the terminal assembly of  FIG. 1  in place on a substrate; 
         FIG. 3  is the same view as  FIG. 2 , but with the cover in place on the terminal assembly; 
         FIG. 4  is a plan view of the insertion of a length of flat flexible cable or flexible printed circuitry that is used with the connectors of the present invention; 
         FIG. 5  is a sectional view showing the flat cable spaced apart from but aligned with the cable connector of the present inventions; 
         FIG. 6  is a sectional view showing the flat cable partially inserted into the to the cable connector of the present invention; 
         FIG. 7  is a sectional view showing the flat cable in place in the cable connector of the present invention; and, 
         FIG. 8  is a cross-sectional view of a known cable connector. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The low vertical profile effected by connectors of the present invention make them particularly suitable for use in mobile telephones. 
     In  FIG. 3 , a cable connector  10  of the present invention is mounted on a substrate  41 , such as a circuit board, and is used to electrically connect a flat cable (FFC/FPC)  51 , as shown in  FIG. 4  to a substrate. 
     In the preferred embodiment, it should be appreciated that the expressions indicating the directions, such as up, down, left, right, front, and rear, which are used to describe the constructions and operations of the cable connector  10  and the flat cable  51 , are relative rather than absolute. These expressions are appropriate when the cable connector  10  and the flat cable  51  are in the position as shown in the drawing figures. However, when the attitudes of the cable connector  10  and the flat cable  51  are changed, these expressions shall be interpreted according to a change in attitude. 
     Referring to  FIG. 4 , the flat cable  51  is suitable for use in a narrow mounting spaces, and has an elongated strip-shaped cable body  52  provided with conductive leads  55 . One surface at a lengthwise end of the elongated cable body  52  is illustrated in an enlarged dimension. In the interior of the cable body  52 , there are a plurality of, e.g., ten leads  55 , which are formed of a foil-shaped conductive metal extending lengthwise of the cable body  52 , and disposed in side by side order of a predetermined pitch, e.g., about 0.5 mm. The number and the pitch of the lead-wires  55  may be suitably changed. The lead-wires  55  are coated so that they are sandwiched from the upper and lower surfaces thereof, by a film-shaped insulating layer exhibiting electrical insulating property. 
     Further, a reinforcing plate  53  is applied, such as by adhesives, to one surface of the ends of the cable body  52 , i.e., on the bottom of  FIG. 4 , and the leads  55  are exposed over a predetermined range in a lengthwise direction from the front edge  56  along the top surface shown therein. The reinforcing plate  53  may be formed of a material with a relatively high hardness, such as polyimide, and covers one surface of the lengthwise ends of the cable body  52  over a predetermined lengthwise range from the front edge  56  of the flat cable  51 , and over the entire width of the cable body  52 . The cable body  52  is inserted from an inserting hole  13 , i.e., an opening provided in the cable connector  10 , with the surface to which the lead-wires  55  are exposed (the surface side when viewed in  FIG. 4 ) disposed above and opposite the substrate  41 . 
     Ear or tab portions  54  are seen projecting outward from the side edges  57  on both sides of the flat cable  51 , and are formed near the end of the flat cable  51 . These ear portions  54  are spaced a predetermined distance away from the front edge  56  of the flat cable  51 , and are formed as part of the cable body  52  and the reinforcing plate  53 . Alternatively, the ear parts  54  may be formed only on the reinforcing plate  53 . It is preferable that the portions where both ends of the front edge  56  and side edges  57  are connected to each other, namely front end corner portions  56   a  are shaped as either a rounded corner or as a taper. 
     Referring to  FIG. 2 , the cable connector  10  has a cover member  11  that covers a terminal assembly  20  in its entirety. The cover member  11  is a member in the shape of a thin rectangular box provided with a plurality of flat wall members. On end is left opened, and leg members  12  extend outwardly are formed on the cover member  11  and are connected to the sidewalls on the right and left sides. The leg members  12  secure the cover member  11  to the substrate  41 , and are firmly fixed to the substrate  41  with an adhesive or the like. The cover member  11  may be formed of an insulating material such as synthetic resin or ceramics, and is formed integrally with the leg parts  12 . Alternatively, the leg parts  12  may be formed separately, and then firmly secured to the cover member  11 . 
     The terminal assembly  20  is a member in the general shape of a flat comb, which has a plurality terminals  31  disposed in side by side order in a predetermined pitch, for example, approximately 0.5 mm, and a terminal support  21  for supporting the terminals  31 . The terminal assembly  20  is mounted on the substrate  41 , and it is covered with the cover member  11 . The number and the pitch of the terminals  31  can be suitably altered so as to correspond to the number and the pitch of the leads  55  of the flat cable  51 . 
     Each of the terminals  31  is an elongated strip-shaped member that is formed of a conductive resilient material extends parallel to the insertion direction of the flat cable  51  (from right to left when viewed in  FIG. 1 ). The terminals  31  are disposed side by side in such a manner so that adjacent terminals do not contact each other. Each of the terminals  31  has a body part  32  that extends along the cable length, or parallel to the direction of insertion of the flat cable  51 , a connecting part  34  extending from the body part  32  forward toward the inserting hole  13  of the connector, and a front end portion  35  at an end opposite side of the body part  32  in the connecting part  34 . Here, the rear portion of the body part  32  is secured to the terminal support  22  so that the terminals are adequately supported. Tail portions  33  of the terminals project from the terminal support  22  so as to connect the terminals to traces on the substrate and surface mount the connector to the substrate. 
     Connected to the terminal front end portion  35  is a cantilevered contact part  36  with a free end extending toward the rear end portion  33  in the insertion direction of the flat cable  51 . Like the connecting part  34 , this contact part  36  also is elongated and extends in parallel to the connecting part  34 . A free end  38  is provided on the contact part  36  and is located proximate to the connection area between the body part  32  and the connecting part  34 . Preferably, the connecting part  34  is disposed so that its lengthwise central axis is offset from the opposite side of the contact part  36  with respect to the lengthwise central axis of the body part  32 . In other words, the connecting part  34  is offset on the opposite side of the contact part  36  with respect to the body part  32 . This permits a reduction in the distance between the lengthwise central axis of the total area of the contact part  36  and the connecting part  34 , and the lengthwise central axis of the body part  32 , thereby permitting a reduction in the distance between the adjacent terminals  31 , resulting in a small pitch. The contact part  36  is integrally connected at the terminal front end portion  35  to the connecting part  34 , without being folded back at the front end portion  35 , so that the contact part  36 , the front end portion  35 , and the connecting part  34  appear on one identical surface. By so doing, it is possible to make the front end portion  35  thinner only with the thickness of the terminal  31 . This facilitates the fitting of the flat cable  51  in the connector  10 . 
     The front end portion  35  is firmly fixed to the surface of the substrate  41  by connecting means such as adhesive, or it may be soldered in place to the substrate. The end of the contact part  36  is connected to the front end portion  35 , and the free end  38  of the terminal thereby functions as a cantilevered member that is movable vertically with respect to the surface of the substrate  41 . A top portion  37  is disposed between the front end portion  35  and the free end  38  in the contact part  36  and is formed to project upward so as to form a ridge or peak when viewed in a lengthwise cross-section. This top portion  37  contacts the exposed leads  55  of the flat cable  51  to establish an electrical connection. When the flat cable  51  is inserted from the inserting hole  13 , because the front end portion  35  is firmly secured to the surface of the substrate  41 , the front edge  56  of the flat cable  51  travels smoothly in the insertion direction thereof, without abutting against the front end portion  35 . In addition, because the upper surface of the contact part  36  has a tilted surface ascending from the front end portion  35  to the top portion  37 , the front edge  56  of the flat cable  51  travels smoothly in the insertion direction along the upper surface of the contact part  36 . 
     The terminal support member  21  is formed of an insulative material such as synthetic resin and has a lateral frame part  22  that holds the terminal body parts  32 . It also has a pair of holding arm parts  23  that extend from both ends of the lateral frame part  22  to the connector inserting hole  13 . The terminal support member  21  is formed so that the lateral frame part  22  is integrated with the body parts  32 , by subjecting the body parts  32  of the terminals  31  through over-molding. The lower surface of the lateral frame part  22  which confronts the substrate  41  is preferably flush with the surfaces of the body parts  32  of the terminals  31  which are opposed to the substrate  41 . The surface of the lateral frame part  22  on the side on which the inserting hole  13  is disposed, namely a front end surface  22   a  abuts against the front edge  56  of the flat cable  51  that is completely inserted. 
     The right and left holding arm parts  23  are spaced apart from each other and are provided with guide surfaces  23   b  that extending in the insertion direction. The guide surfaces  23   b  act to guide the side edges  57  of the flat cable  51 , and positioning the lateral direction of the flat cable  51 , in the direction of arrangement of the terminals  31 . The holding arm parts  23  have engaging convex portions  24  that project inwardly at the end on the opposite side of the lateral frame part  22 , namely at the free end, and fitting concave portions  25  that are recessed outwardly on the side of the engaging convex portions  24  on which the lateral frame part  22  is disposed. A portion of each of the holding arm parts  23  adjacent to the free end is a narrow portion  23   a  that is small in width, and thus has flexibility, which allows for resilient bending in the direction of extension of the lateral frame part  22 , namely the direction of arrangement of the terminals  31 . Thus, when the flat cable  51  is inserted, the free ends of the holding arm parts  23  are resiliently displaced in the direction of arrangement of the terminals  31 , so that the ear parts  54  of the flat cable  51  fit into the fitting concave portions  25 . 
     As a result, the holding arm parts  23  hold the flat cable  51 , thereby grasping the flat cable  51  and preventing disengagement of the flat cable  51  from the connector  10 . Then, if the flat cable  51  is subjected to a force in the removal direction, the force by which the flat cable  51  is disengaged from the cable connector  10 , the flat cable  51  is held against the displacement in the reverse direction of the insertion direction, by the engagement of the engaging convex portions  24  to the rear ends of the ear parts  54  of the flat cable  51  inserted into the fitting concave portions  25 . That is, the engaging convex portions  24  function as stoppers to prevent disengagement of the flat cable  51 . 
     The tapered surfaces  24   a  are tilted with respect to the insertion direction of the flat cable  51  on the free end sides of the engaging convex portions  24 , so that the front corners  56   a  of the flat cable  51  travel while abutting against the tapered surfaces  24   a , thereby adjusting the lateral position of the flat cable  51 . In addition, the free ends of the holding arm parts  23  are forced outward by the ear parts  54  of the flat cable  51  while abutting against the tapered surfaces  24   a.  The operation of the cable connector  10  having the above-mentioned construction will next be described in terms of connecting the cable to the connector.  FIG. 5  is a first sectional view showing the connecting of a flat cable to the cable connector. 
     It is assumed that the cable connector  10  is mounted on the substrate  41  by soldering the terminal rear end portions  33  to connecting pads on the substrate  41 , while the front end portions  35  of the terminals  31  are preferably connected with by adhesive onto the surface of the substrate  41 , and the leg parts  12  of the cover member  11  are also connected with adhesive onto the surface of the substrate  41 . The adhesive firmly secures the front end portions  35  to the substrate  41  requires no soldering pattern, allowing for effective utilization of the space of the substrate  41 . If the substrate  41  has an enough space, the front end portions  35  may be firmly secured by soldering to a soldering pattern formed on the substrate  41 , instead of using the adhesive. It is also assumed that the thickness of the terminal support  21  is identical with or slightly smaller than the dimension between the lower surface of the cover member  11  secured to the substrate  41  and the upper surface of the substrate  41 . 
     Referring to  FIG. 5 , when connecting the flat cable  51  to the cable connector  10 , the ends of the flat cable  51  are set parallel with the substrate  41 , and the front edge  56  of the flat cable  51  is brought toward the inserting hole  13  of the connector so that the parallel to the inserting hole  13  are parallel with each other. The exposed leads of the flat cable face down in opposition to the upper surface of the substrate  41 . 
     Referring to  FIG. 6 , the flat cable  51  is then inserted with the lengthwise end of the flat cable  51  being inserted into the inserting hole  13  of the cable connector  10 . The front end portions  35  of the terminals  31  are connected and secured to the surface of the substrate  41  by adhesive or by solder, they are tightly stuck and secured to the substrate  41 . Therefore, the front edge  56  of the flat cable  51  is smoothly inserted without abutting against the front end portions  35 . The upper surfaces of the contact parts  36  have the tilted surfaces that rise as the flat cable  51  travels further inwardly, and the front edge  56  of the flat cable  51  also smoothly travel along the upper surfaces of the contact parts  36 . At this time, the exposed leads  55  on the lower surface of the flat cable  51  abut the upper surfaces of the contact parts  36  to make a connection. 
     In a case where the position of the flat cable  51  deviates in the lateral direction, namely the direction of arrangement of the terminals  31 , when the lengthwise end of the flat cable  51  is inserted from the inserting hole  13  into the cable connector  10 , the front end corner portions  56   a  travel while abutting against the tapered surfaces  24   a  formed at the free ends of the holing arm parts  23  of the terminal supporting member  21 . With this construction, the position in the direction of arrangement of the terminals  31  of the flat cable  51  can be adjusted so that the leads  55  of the flat cable  51  are in registration with the terminal contact parts  36 . When the flat cable  51  further travels inwardly, the side edges  57  of the cable are guided by the guide surfaces  23   b  of the right and left holding arm parts  23 . This provides the positioning of the flat cable  51  in the direction of arrangement of the terminals  31 , permitting a sure and reliable contact between the respective leads  55  and the corresponding contact parts  36  of the terminals  31 . 
     In  FIG. 7 , the insertion of the flat cable  51  is completed when the front edge  56  of the flat cable  51  abuts against the front end surface  22   a  of the lateral frame part  22  of the terminal support member  21 . Since the thickness of the terminal support member  21  is identical with or slightly smaller than the dimension between the lower surface of the cover member  11  secured to the substrate  41  and the upper surface of the substrate  41 , the lateral frame part  22  is not rotated and maintains its stable state at the time of the abutment of the front edge  56  of the flat cable  51  against the front end surface  22   a . The contact parts  36  of the terminals  31  abut against their respective corresponding leads  55  that are exposed to the lower surface of the flat cable  51 , and are electrically connected thereto. This completes the connection of the flat cable  51  to the cable connector  10 . 
     When the flat cable  51  is not inserted, as shown in  FIG. 5 , the top portions  37  of the contact parts  36  are in contact with, or in an elevated position adjacent to the lower surface of the cover member  11 . The free ends  38  of the contact parts  36  are in an elevated position away from the upper surface of the substrate  41 . As the flat cable  51  travels in the insertion direction with respect to the cable connector  10 , the contact parts  36  are forced downward by the flat cable  51 . When the insertion of the flat cable  51  is completed, as shown in  FIG. 7 , the contact parts  36  are down forced from above by the cable  51 , and are deformed resiliently, resulting in an approximately flat shape. At this time, the contact parts  36  are urged upwardly due to the resilient deformation of the contact parts  36 , and the top portions  37  of the contact parts  36  press into contact with their corresponding exposed leads  55  on the lower surface of the flat cable  51 . It is therefore possible to maintain a superior connection with the lead-wires  55 . In this case, the contact parts  36  are displaced by the vertical movements of the free ends  38  with respect to the surface of the substrate  41 . When the free ends  38  are brought into contact with the surface of the substrate  41  before the contact parts  38  are displaced, the contact pressure between the top portions  37  and the lead-wires  55  can be increased. In this case, the free ends  38  travel on the surface of the substrate  41  in the insertion direction of the flat cable  51 , depending on the displacements of the contact parts  36 . 
     Additionally, the free ends of the holding arm parts  23  are forced outward by the traveling of the ear parts  54  of the flat cable  51  while abutting against the tapered surfaces  24   a.  Therefore, the ear parts  54  fit into the fitting concave portions  25  at the completion of the insertion of the flat cable  51 , so that the pair of the holding arm parts  23  holds the flat cable  51 , and the flat cable  51  can be resistant against disengagement from the cable connector  10 . Since the thickness of the terminal suppor  21  is identical with or slightly smaller than the dimension between the lower surface of the cover member  11  secured to the substrate  41  and the upper surface of the substrate  41 , the holding arm parts  23  may deform in the direction of arrangement of the terminals  31 , however, do not deform in the direction orthogonal to the direction of arrangement, namely the vertical direction when viewed in  FIG. 7 . This permits a reliable fitting of the ear parts  54  into the fitting concave portions  25 . There is also no possibility of release of the fitting of the ear parts  54  into the fitting concave portions  25 , due to the vertical deformation of the holding arm parts  23 . 
     Thus, in the foregoing preferred embodiment, the cable connector  10  includes the terminals  31  that extend in the direction of the insertion of the flat cable  51 . Each of the terminals has the front end portion  35  and the rear end portion  33  that are firmly secured to the surface of the substrate  41 , and the free end  38  that is movable in the vertical direction to the surface of the substrate  41 , and is disposed between the front end portion  35  and the rear end portion  33 . This thin and simple structure permits an easy insertion of the flat cable  51  without causing abutment of the front end portions  35  of the terminals  31  against the flat cable  51 . 
     Each of the terminals  31  is provided with the contact part  36  that makes a contact with the corresponding lead-wires  55  of the flat cable  51  and extend in the insertion direction, one end of the contact part  36  being connected to the front end portion  35 , and the other being the free end  38 . This provides sure and reliable electrical connection of the contact parts  36  with the lead-wires  55 , thereby enabling the flat cable  51  to be reliably connected to the cable connector  10 . 
     Further, the cable connector  10  has the terminal support  21  formed of an insulating material, which is provided with the lateral frame part  22  that extends in the direction of arrangement of the terminals  31  and is secured to the body parts  32  of the terminals  31 , and the pair of holding arm parts  23  that are connected to the both ends of the lateral frame part  22  and extend in the insertion direction. Hence, the positional relationship between the terminals  31  can be stabilized to facilitate handling of the terminals  31  and facilitate manufacturing of the cable connector  10 . 
     Further, the flat cable  51  has the ear parts  54  projecting from the both ends, and the holding arm parts  23  have the fitting concave parts  25 , into which the ear parts  54  are fit. This enables the flat cable  51  to be reliably connected without causing disengagement thereof. 
     It is to be understood that the present invention is not limited to the foregoing preferred embodiment but it is susceptible of various changes and modifications based on the concept of the present invention, which may be considered as falling within the scope of the present invention.