Abstract:
A system provides an electrical connection with a flat circuit and includes a generally rigid dielectric support structure. The flat circuit is located on one side of the support structure. A terminal includes a contact portion at an opposite side of the support structure for electrically engaging a complementary connecting device. A shank portion of the terminal extends from the contact portion through the support structure. A terminating portion at an end of the shank portion is terminated to an appropriate conductor of the flat circuit at the one side of the support structure.

Description:
FIELD OF THE INVENTION 
     This invention generally relates to a system and method for providing an electrical connection with a flat circuit, such as in a cover assembly for a mobile telephone. 
     BACKGROUND OF THE INVENTION 
     There are a wide variety of systems and methods for terminating the conductors of flat circuits, such as flat flexible circuits, flexible printed circuit boards and the like. A flat flexible circuit conventionally includes an elongated flat flexible dielectric substrate having a pattern of conductors on one or both sides thereof. The conductors may be covered with a thin, flexible protective layer or film on one or both sides of the circuit. If protective layers or films are used, cutouts are formed to expose the underlying conductors where the conductors are to engage the conductors or terminals of a complementary connecting device which may be a second flat circuit, a printed circuit board, discrete electrical wires or the terminals of a complementary connector. 
     In many applications, flat flexible circuits are supported on some form of generally rigid dielectric support structure. This enables the flexible circuit to be mounted or supported in a given apparatus, and the conductors are easier to be terminated or electrically connected to the conductors or terminals of the complementary connecting device. In one application involving the cover of a mobile telephone, it has become necessary to mount a flat flexible circuit on one side of the cover while engaging and/or disengaging the conductors with a connecting device, such as a switch, on an opposite side of the cover. For instance, a switch located at the inside or bottom of the cover may be actuated in response to the cover moving between open and closed positions. However, the flat flexible cable is located on the opposite or top side of the cover. This creates problems and there is a need for a system and method of electrically engaging or operatively extending the conductors of the flat circuit on the top of the cover with switch contacts located at the bottom of the cover. The present invention is directed to solving these problems and satisfying that need. 
     SUMMARY OF THE INVENTION 
     An object, therefore, of the invention is to provide a new and improved electrical connection system for a flat circuit. 
     Another object of the invention is to provide a new and improved method for providing an electrical connection with a flat circuit. 
     A further object of the invention is to provide a new and improved cover assembly for a mobile telephone. 
     In the exemplary embodiment of the invention, the system and method generally includes a rigid dielectric support structure, with a flat circuit on one side of the support structure. A terminal clip includes a contact portion at an opposite side of the support structure for electrically engaging a complementary connecting device. The terminal clip includes a shank portion extending from the contact portion through the support structure. A terminating portion is provided at an end of the shank portion at the one side of the support structure for termination to an appropriate conductor of the flat circuit. 
     As disclosed herein, the system and method is disclosed in a cover assembly for a mobile telephone. The rigid dielectric support structure is a cover of the assembly, the cover having first and second sides with at least one aperture passing therethrough between the sides. The flat circuit is mounted on the first side of the cover. The contact portion of the terminal clip is located at the second side of the cover for engaging the complementary connecting device. The shank portion of the terminal clip extends from the contact portion through the aperture in the cover and is terminated to the conductor of the flat circuit. 
     The contact portion of the terminal clip herein comprises a contact plate juxtaposed against the second side of the cover. The terminating portion of the terminal clip comprises a distal end of the shank portion bent into engagement with the conductor. The cover includes a pair of apertures, and the terminal is generally U-shaped with a pair of the shank portions extending from opposite ends of the contact portion through the pair of apertures. The flat circuit herein comprises a flat flexible circuit. 
     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 
     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: 
     FIG. 1 is a perspective view of a cover assembly for a mobile telephone, incorporating the concepts of the invention and looking toward the underside of the cover and with the cover raised; 
     FIG. 2 is a perspective view of the cover assembly of FIG. 1, looking toward the top side of the cover; 
     FIG. 3 is a view similar to that of FIG. 2, with the top plate and flat circuit of the cover removed to show the support plate for the flat circuit; 
     FIG. 4 is a view similar to that of FIG. 3, but with the flat circuit mounted on top of the support plate; and 
     FIGS. 5A-5E are fragmented perspective views showing the steps in terminating the flat circuit. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings in greater detail, and first to FIG. 1, the invention is embodied in a cover assembly, generally designated  10 , for a mobile telephone. The cover assembly includes a base  12  appropriately mounted on the mobile telephone and a cover, generally designated  14 , pivotally mounted on the base for movement in the direction of double-headed arrow “A” between a closed position and an open position (as shown). Base  12  mounts a pair of laterally spaced switches, generally designated  16 , on the inside thereof. Only the left-hand switch is visible in FIG.  1 . Nevertheless, each switch includes one or more upwardly extending, vertically reciprocating switch pins  18 . In the industry, such switches commonly are called “pogo pin connectors”. 
     Referring to FIGS. 2-4 in conjunction with FIG. 1, cover  14  includes a generally rigid top plate  20  which is hinged at  22  to base  12  for pivotal movement in the direction of double-headed arrow “A”. The top plate has a plurality of apertures  24  which receive a plurality of dome-shaped push-buttons of a conventional keypad (not shown) mounted on the top of the cover. A generally rigid bottom support plate  26  (FIG. 3) is snap-fit into the underside of top plate  20 . A flat flexible circuit  28  (FIG. 4) is sandwiched between top plate  20  (FIG. 2) and bottom support plate  26  (FIG.  3 ). The circuit has conductor pad arrays  29  for engagement by the push buttons of the keypad. It should be understood that, in actual practice, bottom support plate  26  in FIG. 3, along with flat circuit  28  in FIG. 4, will not be unsupportedly suspended as shown in FIGS. 3 and 4, i.e., without top plate  20  (FIG.  2 ), These depictions are shown simply to provide a better understanding of the laminated or multi-layered assembly of cover  14 . FIG. 1 shows that a liquid crystal display (LCD)  30  is disposed on the upper portion of base  12 . 
     FIGS. 5A-5E show the system and method for providing an electrical connection with or terminating flat circuit  28  on top of bottom support plate  26  so that the conductors thereof can be operative for engaging switch pins  18  at the bottom of the support plate beneath cover  14 . The system includes the use of a plurality of terminal clips or terminals, generally designated  32 , which are visible in FIGS. 1 and 4. 
     More particularly, bottom support plate  26  includes a pair of laterally spaced leg portions  26   a  (FIGS.  3  and  4 ), one of which is shown in FIGS. 5A-5E. The bottom support plate and leg portions have a first or top side  36  (FIG. 5A) and a second or bottom side  38 . Flat flexible circuit  28  is disposed on top side  36  of the support plate and includes leg portions  28   a  which are juxtaposed over leg portions  26   a  of the support plate. Flat flexible circuit  28  includes a pattern of conductors  40  (FIG. 4) with a pair of conductors  42  extending into each leg portion  28   a  as seen in FIG.  5 A. If flat flexible circuit  28  is provided with a protective layer or film, the film is removed to expose conductors  42  at the top of the circuit. Each leg portion  26   a  of support plate  26  includes two pairs of apertures  44  which are aligned with two pairs of holes  46  in leg portions  28   a  of flat circuit  28 . Holes  46  extend through conductors  42  as clearly seen in FIGS. 5A-5E. 
     As best seen in FIGS. 5A and 5B, each terminal clip or terminal  32  is generally U-shaped and includes a contact portion or section  32   a  in the form of a flat contact plate. A pair of shank portions or connecting sections  32   b  project from opposite ends of contact portion  32   a . The shank portions terminate in distal ends  32   c  which will form terminating portions of the terminal, as will be seen below. Although only one terminal  32  is shown in FIGS. 5A-5E, four terminals  32  are used with cover  14  as seen in FIGS. 1 and 4. One terminal is used for each of the two pairs of apertures  44  in support plate  26  and holes  46  in flat circuit  28  at each opposite side of the cover assembly. 
     The system and method of the invention using terminals  32  now will be described in relation to FIGS. 5A-5E. Flat flexible circuit  28  first is mounted or positioned onto top side  36  (FIG. 5A) of support plate  26  as seen in FIG.  5 B. The flat circuit may be appropriately adhered to the top side of the support plate, or the circuit may be press-fit within an array of ribs  50  (FIG. 4) projecting upwardly from the support plate. Terminals  32  then are assembled in the direction of arrow “B” (FIG. 5B) by inserting shank portions  32   b  first through apertures  44  in support plate  28  and then through holes  46  in flat circuit  28  until the shank portions extend completely through the assembly as shown by the one terminal in FIG.  5 C. The distal ends of the shank portions then are bent inwardly in the direction of arrows “C” (FIG. 5C) until the distal ends form terminating portions  32   c  as shown in FIG.  5 D. The terminating portions are bent inwardly until they tightly engage conductors  42  of flat flexible circuit  28 . 
     From the foregoing, it can be seen that flat flexible circuit  28  is mounted to a first or top side  36  of support plate  26 , while terminals  32  are mounted through a second or bottom side  38  of the support plate. When filly assembled, contact portions  32  of the terminals are located at the bottom of cover  14  as seen in FIG. 1, notwithstanding the fact that flat flexible circuit  28  is mounted on the top of support plate  26 . By using this system, conductors  40  (FIG. 4) can be operatively associated with the keypad of the mobile telephone through apertures  24  (FIG. 2) at the top of the cover assembly, while conductors  42  (FIGS. 5A-5C) are operatively associated by terminals  32  through the cover assembly with switches  16  located at a completely opposite side of cover  14 . 
     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.