This application is a division of application Ser. No. 08/822,715, filed Mar. 24, 1997, now U.S. Pat. No. 6,056,590. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to an electrical connector, particularly to an electrical connector for connecting a plurality of electric circuits by mechanical coupling with a counter electrical connector, and a fabrication method of the connector. 
     2. Description of the Prior Art 
     FIGS. 1A through 1C are plan, front, and sectional views of a prior art male connector with a dual-in-line half-pitched contact array for the SCSI specification, respectively. The male connector is composed of an insulating housing  41  encapsulated by a metal shell  42 , and a array of contact members  43  inserted into dual-in-line rectangular shaped through-holes  44  of the insulating housing  44 . While FIGS. 2A through 2C are plan, front, and sectional views of a prior art dual-in-line female connector, respectively, which mechanically couples with the male connector to make an electric connection as shown in FIGS. 1A through 1C. The female connector is composed of an insulating housing  21 , a metal shell  22 , an array of pairs of upper and lower contact members  23  inserted into rectangular shaped through-holes  24  to be fixed to the insulating housing  21 , and an insulating base  26  having terminal-supporters  25  gaplessly continuous to the insulating housing  21 , in which each of the upper and lower contact members  23 , made by a metal plate, has a body  30 , a pair of spring contacts  28  at a front end of the body with respective opposing contact parts  29 , and an L-shaped terminal  27  at a back end. Further, FIGS. 3A and 3B are sectional views of another type of prior art inline male and female connectors, respectively. In both cases, the male connectors shown in FIGS. 1A through 1C and FIG. 3A couple with the female connectors shown in FIG.  2 B and FIG. 3B by inserting each of the respective male contacts  43  and  49  thereof into the corresponding female spring contacts  28  and  33  thereof, respectively. Although a pair of the spring contacts of the female connector squeezes the inserted contact of the male connector, incomplete coupling often occurs due to severe jarring or accidental pull of a cable. Such an incomplete coupling of connector may give rise not only to a not simple disconnection of the electric circuits but also to an unrecoverable breakdown of the input circuit due to a sudden increase of an input impedance. For example, if an input terminal is opened while the input circuit is activated, the input circuit is often damaged, particularly an input circuit to an MOSLSI circuit. Therefore, it is desirable that the input circuit is activated after the input terminal is terminated with a proper input impedance by complete coupling of connectors. Further, it may be convenient in some cases that a complete or an incomplete coupling of connectors is correspondingly indicated by a suitable indicator, such as a warning lamp or a signal on a display. Therefore, it is needed to detect whether a coupling of connectors is completed or not. However., either case of the prior art connector has nothing to do for these inconvenience. Of course, the circuit can be protected by some protective circuit, but it incurs no little expense and complex circuits. These inconveniences and requirements must be improved simultaneously to achieve an advanced, improved connector. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a connector having a detector means for detecting whether the connector is coupled or decoupled with the counter connector. 
     Another object of the present invention is to provide an internal connector which is mounted on an electric instrument having an electric module for changing a state by coupling or decoupling with the external connector. 
     A further object of the present invention is to provide a connector having an electric switch for changing a state by coupling or decoupling with the counter connector. 
     Still a further object of the present invention is to provide a method for making a female connector having an electric module for changing a state by coupling or decoupling with the corresponding male connector. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be more apparent from the following description, when taken to conjunction accompanying drawings, in which: 
     FIGS. 1A through 1C are plan, sectional, and front views, respectively of a prior art male connector with a dual-in-line half-pitched contact array in conformity with the SCSI specification. 
     FIGS. 2A through 2C are plan, sectional, and front views, respectively, of a prior art dual-in-line female connector. 
     FIGS. 3A and 3B are sectional views, respectively, of another type of prior art in-line male and female connectors. 
     FIGS. 4A through 4C are sectional, plan, and front views, respectively, of a left hand side of a dual-in-line connector with the contact module in accordance with a first embodiment of the invention. 
     FIGS. 5A through 5C and  5 D are plan, sectional, sectional and a front views of a contact module according to a first embodiment of the present invention and a sectional view of a housing for the contact module, respectively. 
     FIG. 6A and 6B are sectional views of a female connector with the contact module according to the first embodiment of the present invention and of a counter connector, respectively. 
     FIGS. 7A through 7D are plan, sectional, and front views of a contact module and a sectional view of a housing according to a second embodiment of the present invention, respectively. 
     FIGS. 8A through 8C are perspective views of a contact module in various steps of fabrication according to a third embodiment of the present invention, respectively. 
     FIGS. 9A and 9B are perspective views of a contact module in various steps of fabrication according to a forth embodiment of the present invention, respectively. 
     FIGS. 10A and 10B are sectional views of a conventional male connector and female connector having a contact module according to the fourth embodiment of the present invention, respectively. 
     FIGS. 11A and 11B are perspective views of a contact module in various steps of fabrication according to the fifth embodiment of the present invention, respectively. 
     FIGS. 12A and 12B are sectional views of a conventional male connector and a female connector having a contact module according to the fifth embodiment of the present invention, respectively. 
     FIG. 13 is a sectional view of the female connector with contact module in FIG. 6A as coupled, or assembled, with the counter connector of FIG.  6 B. 
     FIG. 14 is a sectional view of the contact module of FIG. 7B assembled with the associated housing therefore of FIG. 7B, in accordance with the second embodiment of the present invention, and further as coupled, or assembled, with the male counter connector of FIG.  6 B. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference will now be made in detail to the preferred illustrated embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred illustrated embodiments, it will be understood that it is not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. 
     Although each of the contacts of a dual-in-line connector is already reserved to its respective role determined by the SCSI specification, many electronic instruments usually do not use all of the contacts. Therefore, one of the unused contact members can be replaced by a contact module for the present invention without interfering with the original role of the connector. 
     FIGS. 4A and 4C illustrate a dual-in-line connector with both a contact module according to the first embodiment the present invention and also a plurality of contact members. 
     The connector  5  of the first embodiment has an insulating housing  21  encapsulated by a metal shell  22 , into which a contact module  51  and plural, common contact members  23 , which may be conventional, are inserted. 
     FIGS. 5A through 5C, and  5 D illustrate a dual-in-line contact module according to the first embodiment of the present invention, and an insulating housing of the dual-in-line connector, respectively. 
     As shown in FIG. 5D, the insulating housing  21  encapsulated by a metal shell  22  has an array of a pair of upper and lower openings  24  arranged along respective upper and lower parallel dual lines, into which a plurality of the conventional contact members  23  and at least one contact module  51  of the present invention are to be engaged. Further, an insulating base  26  having a plurality of terminal supports  25  is gaplessly continuous to the insulating housing  21 . Each of the insulating base  26  is positioned under a corresponding opening  24 . The contact module  51 , as shown in FIGS. 5A through 5C, is composed of first and second spring contact members  52 ,  53  made of metal and an insulating mold  54  separating the first and second spring contact members  52 ,  53  by a certain distance from each other by molding both bodies  55 , 60 . The first spring contact member  52  is continuously (i.e., integrally) composed of a body  55 , three substantially parallel spring contacts  56 , 57 , 58  and an L-shaped terminal  59 , which are extended forward and backward from the body  55 , respectively. The second spring contact member  53  is also continuously (i.e., integrally) composed of a body  60 , a spring contact  61  and an L-shaped terminal  62 , extended forward and backward from the body  60 , respectively. The second spring contact member  53  is separated from the first spring contact member  52  by a certain distance by the insulating mold  54  such that both are opposing to each other, side by side. A contact part  63  of the first spring contact  56  is opposing to a contact part  64  of the second spring contact  57 , while contact part  65  of the third spring contact  58  is opposing to a contact part  66  of the fourth spring contact  61 . To mount the contact module  51  to the housing  21  and metal shell  22 , both first and second spring contact members  52 ,  53  are inserted into the corresponding openings  24  such that bezels  67  formed in each by opposite sides of the bodies  55  and  60  cut into internal walls of the openings in order to prevent the inserted spring contact members from coming out of the openings. The contact module  51  replaces a selected pair of the upper and lower contact members  23 , which are unused in a female connector  5 , by removing the existing pair of contact members  23  from the respective pair of openings  24  and inserting the contact module  51  into that selected pair of openings  24 , as shown in FIGS. 4A through 4C. 
     FIG. 6A and 6B are sectional view s of a female connector  5  with the contact module  51  according to the first embodiment: of the present invention and of a counter (mode) connector  15 , respectively. 
     Thus, the female connector  5  with the contact module  51  of FIG. 6A can be coupled with a conventional male connector  15  of FIG. 6B as shown in FIG.  13 . When the male connector  15  is inserted into the female connector  5  with the contact module  51 , a pair of the upper and lower contacts  43  of the male connector  15  are shorted by the first contact member  52 , and the third spring contact  58  of the first contact member  52  is shorted to the forth spring contact  61  of the second contact member  53 . Therefore, for instance, with a detecting circuit  8  is connected between the first contact member  52  and the second contact member  53 , it can be known by the electric short between both members due to an insertion of a pair of the contacts  43  that a coupling between the male connector  15  and the female connector with the contact module is carried out. A slight difference in the opposing position between the contact part  65  of the third spring contact  58  and the contact part  66  of the forth spring contact  61  avoids instability in an ON or OFF state due to chattering during transition between coupling and decoupling. 
     FIGS. 7A through 7D illustrate a dual-in-line contact module and its housing according to the second embodiment of the present invention, which is a modified case of the first embodiment of the present invention. 
     The modified contact module  74  of FIGS. 7A,  7 B and  7 C has a mold spring  75  (i.e., molded integrally with) having a latch  76  on the upper part of the original contact module  51 , other parts and functions of which are the same as those of the original contact module  51 . The housing  71  engaged into the shell  22  as shown in FIG. 7B has a third opening  72  for receiving the mold spring  75  of the modified contact module and an empty space  73  for receiving the latch  76  of the mold spring  75  in addition to a pair of the upper and lower openings  24  as shown in FIG.  14 . The mold spring  75  and latch  76  fasten the modified contact module  74  to the housing  71  to prevent the modified contact module  74  from coming out of the housing  71  when the male connector is coupled to the female connector as also shown in FIG. 14. A clearance between the first and second contact members must be accurate, otherwise, a contact pressure of squeezing the contact  43  between the contact part  65  of the first spring contact  58  and the contact part  66  of the second spring contact  61  becomes unstable. Therefore, an accuracy in this clearance is essential for the contact module for the present invention. For this purpose, a novel fabrication method for contact module has been developed as described below. 
     FIGS. 8A through 8C are bird (i.e., perspective, elevational) views of a contact module in various steps of fabrication according to the third embodiment of the present invention, respectively. 
     As a first step of the fabrication process, as shown in FIG. 8A, a monolithic metal frame  69  is provided, in which patterns of the first and second contact members  52 ,  53  are connected to each other by bridges  68  such that an accurate clearance is maintained between both contact members. Next, as shown in FIG. 8B, a part of the monolithic metal frame  69 , mainly the bodies  55 ,  60  and their neighboring regions, is fixed with an insulating mold  54  by an insert mold technique such that the bridges  68  are exposed in respective windows  70 . Finally, as shown in FIG. 8C, the bridges  68  are cut off in each of the windows  70 , which results in both contact members being electrically isolated while still maintained with accurate clearance between them. The fabrication method described above has ensured reproducibility in the precise clearance and manufacturability in commercial production. 
     FIGS. 3A and 3B are sectional views of another type of prior art in-line male and female connectors, respectively. 
     A female connector  18  has an insulating housing  31  engaged into a shell  32 , in which each of contact members  33  is inserted into the respectively corresponding one of the prior of upper and lower opening  34 , arranged in parallel. Each of contact members  33  has a terminal extended downwardly through a through-hole  35  of an insulating base  36 . The insulating base  36  is gaplessly continuous to the insulating mold  31 . While a counter male connector  19  is composed of an insulating mold  45  encapsulated by a metal shell  46  and a pair of spring contacts  47  having respective contacts  49 , each of which is engaged in one of a pair of through-holes  48  of the insulating mold  45 . The pair of spring contacts  47  are isolated from each other by an insulating wall therebetween. 
     FIGS. 9A and 9B are bird (i.e., elevational, perspective) views of a contact module in various steps of fabrication according to the fourth embodiment of the present invention, respectively. 
     The contact module  80  shown in FIG. 9B according to the fourth embodiment, is to be mounted on the conventional connector  18  shown in FIG.  3 B. As shown in FIG. 9A, the spring contacts  82 ,  84 , are continuous to the terminal  88 , while the spring contact  83  is continuous to the terminal  89 . As shown in FIG. 9B, an insert mold  81  fixes relative dimensions of the spring contacts and the terminals to one another such that three spring contacts  82 ,  83 ,  84  extend horizontally out of one side and two terminals  88 ,  89  extend downwardly out of a bottom side. Thus, the contact module  80  can be mounted on the female connector  18  by replacing an unused one of contact members  33  such that each of the spring contacts  82 ,  83 ,  84  and terminals  88 ,  89  are inserted into the openings  34  and the through holes  35 , respectively. When the spring contacts  82 ,  83 ,  84  are inserted into the openings  34 , bezels  38 , formed in each root, cut into the internal side walls of the openings, by which the contact module  80  is prevented from coming out of the connector  18 . 
     FIGS. 10A and 10B are sectional views of a conventional male connector and female connector having a contact module according to the fourth embodiment of the present invention, respectively. 
     Since the contact module  80  has the same spring contacts as those of the replaced contact member  33 , the female connector  6  having the contact module  80  can be coupled with the conventional male connector  19  without any mechanical problem. Therefore, when the conventional male connector  19  shown in FIG. 10A is coupled with the female connector  6  shown in FIG. 10B having the contact module  80 , the upper and lower spring contacts  47  are shorted by the fifth spring contact  82  and the seventh spring contact  84 , while the sixth spring contact  83  and the seventh spring contact  84  are shorted by the lower spring contacts  47 , and it eventually shorts between the terminals  88  and  89 . With the terminals  88  and  89  connected to a detection circuit  8 , the electric short of them can be recognized as an insertion of the male connector  19 . 
     FIGS. 11A and 11B are bird (perspective, elevational) views of a contact module in various steps of fabrication according to the fifth embodiment of the present invention, respectively. 
     A contact module according to the fifth embodiment of the present invention affords another example of the female connector  6  which can be coupled with the conventional male connector  19 . The contact module has an insulating mold  91  from which a fifth spring contact  82  and a sixth spring contact  83 , and first and second shorting contacts  92 ,  93  stick out of the same front wall. The spring contact  82  and the sixth spring contact  83  have contacts  85 ,  86  opposing to each other, respectively. As shown in FIG. 11A, the first and second shorting contacts  92 ,  93  are connected to the fifth spring and sixth spring contacts  82 ,  83 , respectively. A terminal  88  of the fifth spring  82  and a terminal  89  of the sixth spring  83  extend out of the bottom side of the insulating mold  91 . 
     FIGS. 12A and 12B are sectional views of a conventional male connector and female connector having a contact module according to the fifth embodiment of the present invention, respectively. 
     As shown in FIG. 12B, the female connector  7  has an insulating housing  31  and a metal shell  32 , where at least a contact module  90  and a plurality of conventional contact members  33  (not shown) are inserted into upper and lower openings  34  of the insulating housing  31 (a partition between the upper and lower openings are not shown). An insulating base  36  having holes corresponding to the upper and lower openings  34  is continuous to a lower part of the insulating housing  31 . The spring contacts  82 ,  83  of the contact module  90  have a bezel  38  in each root so that the bezel eats into the side wall of each opening  34  when the contact module  90  is inserted into the opening  34  to prevent the spring contacts  82 ,  83  from coming out of the opening  34  easily. If the insulating wall of the openings  34  is removed, the contact module  90  can replace one of the contact members without any mechanical problem, which can receive a pair of the spring contacts  49  of the conventional male connector  19 . 
     Thus, when the male connector  19  couples to the female connector  7 , the spring contacts  47  are, separately and individually, electrically connected to the fifth and sixth contacts  82 ,  83 , respectively, and the first shorting contact  92  is pushed by the housing  45  of the male connector  7  toward the second shorting contact  93 , such that the first shorting contact  92  and the second shorting contact  93  are eventually shorted. With a detector circuit  8  connected between the terminals  88  and  89  of the fifth and sixth contacts  82  and  83 , respectively the coupling of the male connector  19  with the female connector  7  is electrically detected. 
     As described above, the contact module according to the present invention is easily replaceable for one of the unused standard contact members in a female connector, and thus modified female connector, incorporating the contact module of the invention, maintains a capability to couple with the conventional counter male connector, exactly the same as before. 
     Although the illustrated embodiments show only such cases that the internal switch mounted in the contact module flips from an OFF state to an ON state by insertion of the male connector, the insertion of the male connector may be equally well detected by, instead, changing a state of the internal switch from ON to OFF.
A method for fabricating a connector for coupling with a counter connector having an array of pairs of contacts therein includes providing an insulated housing having an array of openings receiving a plurality of first contact modules each having first and second isolated contacts and a second contact module having isolated first and second conducting members respectively having first and second contacts and a terminal, and a third contact and a second terminal, selectively inserted into corresponding openings of the insulating housing such that each of the respective first and second contacts of the first contact modules are connected with the corresponding contact of the counter connector while maintaining the first and second contacts electrically isolated from each other. Further, the second contact modules are inserted into corresponding openings of the insulating housing, not used for the first contact modules and such that the first contact of the second contact module is connected with one contact of the corresponding pair of contacts of the counter electrode and both the second and third contacts are electrically connected with the other contact of the corresponding pair of contacts of the counter electrode when the connector is coupled with the counter connector.