Patent Publication Number: US-6340308-B1

Title: Electrical connector

Description:
FIELD OF THE INVENTION 
     The present invention relates to an electrical connector which is used for information exchange with a card-like memory module, such as a miniature card, which has a plurality of flat contacts for signal transmission on its surface. 
     BACKGROUND OF THE INVENTION 
     An example of card-like memory module of the type mentioned above, which has a plurality of flat contacts arranged on a surface for signal transmission, is a miniature card which is made smaller than a conventional IC card and is used as memory, for example, in a small size computer. As shown in FIG. 10, the miniature card  70  is a plate-like rectangular form and includes three power-supply contacts  71  and first and second grooves  72  and  73 , each having a different width. The first groove  72 , which is wider, is used to position the miniature card correctly in the housing of a connecter, into which the miniature card is inserted. The second groove  73 , which is narrower, is to prevent accidental insertion into a connector which has a different voltage rating other than the one rated for the miniature card. For a miniature card whose voltage rating is different, the second groove  73  is provided at a different position. Therefore, the miniature card  70  can be inserted into only those connectors which have a right voltage rating. The miniature card  70  further includes a plurality of signal-transmission contacts  75 , which are fixed in the laterally extending two rows of contact-mounting grooves  74  that are provided near the lower end  70   a  on the rear surface  70   b  of the miniature card  70 . Furthermore, near the contact-mounting grooves  74  and on the lateral sides of the card, recesses  76  are provided for engagement. 
     The miniature card  70  is installed into an electrical connector of a computer, which connector comprises a plurality of signal-transmission contacts in a plate-like housing. In this installed condition, the signal-transmission contacts  75  and the power-supply contacts  71  of the miniature card  70  are in contact with the corresponding signal-transmission contacts and the corresponding power-supply contacts of the connector and ready for information exchange with the computer. In the installation of the miniature card  70  into the connector, at first, the lower end  70   a  of the miniature card  70  is inserted obliquely into a groove which is provided in the housing of the connector, and the power-supply contacts  71  of the miniature card  70  are pressed onto the power-supply contacts of the connector which are provided in the groove. Then, the miniature card  70  is turned around the lower end  70   a  thereof to bring the miniature card  70  substantially parallel to the housing of the connector. As a result, the signal-transmission contacts  75  of the miniature card  70  are brought into contact with the signal-transmission contacts of the connector. In this condition, the miniature card  70  is retained securely in the housing of the connector and is locked therein by a locking mechanism which is provided on the housing. In general, the signal-transmission contacts of the connector are mounted in contact grooves which are provided in the housing of the connector, such that the signal-transmission contacts extend parallel to the length of the housing for a certain distance, and then the contact portions which are provided at the front ends of the signal-transmission contacts come out of the housing for electrical contact, each bending in a Z-shape. 
     A so-called horizontally mounted connector is such a connector which is mounted in the front and rear direction horizontally on a printed circuit board. In this connector, the contact portions of the signal-transmission contacts are aligned in two front and rear rows, protruding upward from the upper surface of the housing. The first signal-transmission contacts whose contact portions are aligned in the front row and the second signal-transmission contacts whose contact portions are aligned in the rear row are mounted into the housing from the front side and the rear side of the housing, respectively. In this case, the lead portions of the first signal-transmission contacts extend forward from the lower surface of the housing while the lead portions of the second signal-transmission contacts extend rearward from the lower surface of the housing. In another example of horizontally mounted connector, the first signal-transmission contacts and the second signal-transmission contacts are mounted into the housing being interchanged one after another from the front end of the housing in a laterally extending zigzag pattern, and all the lead portions of the first and second signal-transmission contacts extend in the same direction (to the front side ). In this case, the second signal-transmission contacts are formed longer than the first signal-transmission contacts, and the top ends of the second signal-transmission contacts are bent laterally in a Z shape, so that the contact portions of the second signal-transmission contacts are positioned rearward than those of the first signal-transmission contacts. 
     On the other hand, a vertically mounted connector, i.e., the above described connector which is mounted vertically on a printed circuit board, requires the contact portions of the signal-transmission contacts to be aligned in two upper and lower rows while the lead portions of all the signal-transmission contacts must be extended downward. This requirement makes it impossible for the signal-transmission contacts to be mounted into the housing both from the upper side and from the lower side of the housing. If the signal-transmission contacts whose ends are bent laterally in a Z shape as mentioned above are to be used, then each of the contacts must be produced individually because they cannot be produced together in a lot from a plate material in a single process. Such design for the contacts is not cost-effective. 
     SUMMARY OF THE INVENTION 
     It is an object of this invention to provide an electrical connector that reduces the number of steps involved for producing the signal-transmission contacts, which are easily mountable into the housing, thereby improving productivity. 
     The present invention provides an electrical connector which comprises a housing and a plurality of signal-transmission contacts (e.g., the first and second signal-transmission contacts  30  and  40  of the following embodiment). The housing comprises a rear wall, which extends substantially vertically, and a front wall, which is provided in front of and parallel with the lower part of the rear wall. The front wall is connected with the rear wall at the lateral sides of the walls. The signal-transmission contacts are arranged in parallel with one another in a laterally extending row in the rear wall, and each of the signal-transmission contacts has a contact portion at one end thereof, each contact portion protruding forward from the rear wall. In this connector, the housing is capable of receiving a card-like memory module (e.g., the miniature card  70  of the following embodiment), which is swung from an inserted position to an installed position in the housing for installation. The inserted position is defined as a condition where the memory module is tilted forward with the upper end thereof being positioned forward and the lower end thereof being shifted downward and inserted into and positioned in a groove that is defined between the rear wall and the front wall of the housing. The installed position is defined as a condition where the memory module is turned around the lower end thereof from the inserted position and is positioned substantially parallel with the rear wall. The memory module has a plurality of flat signal-transmission contacts arranged in a row on a flat surface thereof. When the memory module is brought into the installed position, the signal-transmission contacts of the memory module come into contact with the contact portions of the signal-transmission contacts of the connector. In the rear wall of the housing, a plurality of contact grooves (e.g., the signal contact grooves  21  of the following embodiment) are provided in a laterally extending row, each contact groove opening forward. Each of the signal-transmission contacts of the connector comprises an anchoring portion, a first arm portion, and a second arm portion. The anchoring portion is fixed in a corresponding contact groove of the housing, and the first arm portion extends upward from the anchoring portion. The second arm portion extends forward from the upper end of the first arm portion and has the contact portion at the forward end thereof. The signal-transmission contacts of the connector are mounted in plurality in a forward and rearward direction in each of the contact grooves, such that the second arm portion of the signal-transmission contact which is positioned rearward in each contact groove extends above and forward longer than the second arm portion of the signal-transmission contact which is positioned forward in the same contact groove. As a result, the contact portions are aligned in upper and lower rows in front of the rear wall. 
     In this design of the connector, a plurality of signal-transmission contacts are provided in each contact groove. Therefore, the number of contact grooves provided in the housing is substantially smaller than that of a similar type prior-art connector. Thus, the design of a metal mold which is used for forming the housing of the connector can be simplified. Also, in this connector, all the signal-transmission contacts are mounted into the housing from one side (i.e., the lower side) of the housing, so the mounting of the contacts into the housing is relatively easy. Furthermore, in the connector of the present invention, the signal-transmission contacts are not configured in a Z shape as the prior-art connector, so they can be produced in a large number in a lot from a plate material. Thus, the manufacturing steps can be simplified to improve productivity. 
     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only and thus are not limitative of the present invention. 
     FIGS. 1A,  1 B and  1 C are a plan view, a front view and a bottom view, respectively, of an electrical connector according to the present invention. 
     FIG. 2 is a side view of the connector, the two-dot chain line “A” in the figure indicating the position of a miniature card which is inserted into the connector while the two-dot chain line “B” indicating the position of the miniature card which has been installed. 
     FIGS. 3A and 3B are a front view and a bottom view, respectively, of a housing which constitutes the connector. 
     FIG. 4 is a sectional view of the housing, taken along line IV—IV in FIG.  3 A. 
     FIG. 5 is a sectional view of the housing, taken along line V—V in FIG.  3 A. 
     FIG. 6 is an enlarged view of the region indicated by circle VI in FIG.  3 B. 
     FIG. 7 is a sectional view of the connector, taken along line VII—VII in FIG.  1 B. 
     FIG. 8 shows a positional relation between the miniature card and the connector when the tilt angle of the miniature card is 20 degrees. 
     FIG. 9 shows a positional relation between the miniature card and the connector when the tilt angle of the miniature card is 40 degrees. 
     FIGS. 10A,  10 B,  10 C and  10 D are a rear view, a side view, a front view and a bottom view, respectively, of the miniature card. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG.  1  and FIG. 2 show an example of connector according to the present invention. This connector  1  comprises a housing  10 , a plurality of contacts, and locking mechanisms  60 , which are provided at the lateral sides of the housing  10 . The housing  10  is integrally formed in a one-piece body of an insulative material such as plastics. The contacts comprise first and second signal-transmission contacts  30  and  40 , which are formed of an electrically conductive material and are retained in the housing  10 , and power-supply contacts  50 , which are also formed of an electrically conductive material and are provided at three locations in the housing  10 . As shown in FIG. 1B, the contact portions  35  of the first signal-transmission contacts  30  and the contact portions  45  of the second signal-transmission contacts  40  are aligned extending laterally in two upper and lower rows, respectively (the contact portions  35  are arranged in the lower row while the contact portions  45  are arranged in the upper row). 
     As shown in FIGS. 3,  4  and  5 , the housing  10  comprises a rear wall  11 , which extends vertically, and a front wall  12 , which faces the lower portion of the rear wall  11  in front of the rear wall  11 , and lateral arms  13 , which connect the rear and front walls  11  and  12  at the lateral ends of the walls  11  and  12  and extend upward. Therefore, as shown in FIGS. 4 and 5, a groove  14 , which extends laterally and opens upward, is defined at the lower portion of the housing  10 , between the rear wall  11  and the front wall  12 . Furthermore, a raised portion  15  is provided protruding forward and extending laterally in the center on the front surface of the rear wall  11 , and lateral raised portions  16  are provided protruding inward on the front surface of the rear wall  11  adjacently inside the lateral arms  13  at a position as high as the central raised portion  15 . In addition, as shown in FIG. 3A, a first protrusion  17  and a second protrusion  18 , which is narrower than the first protrusion  17 , are provided next to each other at the upper end of the front wall  12 . 
     As shown in FIG.  3 B and FIG. 6, a plurality of plate-like portions  19  are provided parallel with one another, each spanning in the front and rear direction and connecting the rear wall  11  and the front wall  12  at the lower end of the groove  14 . As a result, a slit  20 , which extends in the front and rear direction, exists between every two neighboring plate-like portions  19 . These slits  20  extend into the rear wall  11  and form signal contact grooves  21 . As shown in FIG.  3 B and FIG. 6, three of the slits  20  extend forward to form power contact grooves  22 . 
     As shown in FIG.  4  through FIG. 6, in the signal contact grooves  21 , first signal contact grooves  23  and second signal contact grooves  24  are provided, each first signal contact groove being aligned with a corresponding second signal contact groove in the front and rear direction, and each first and second signal contact groove widens in the lateral direction and extends in the up and down direction. Also, as shown in FIG.  5  and FIG. 6, in the power contact grooves  22 , power contact mounting grooves  25  are provided, respectively, each widening laterally and extending in the up and down direction. 
     As shown in FIG. 7, each of the first signal-transmission contacts  30  comprises an anchoring portion  31 , a lead portion  32 , a first arm portion  33 , and a second arm portion  34 . The anchoring portion  31  has a width wider than that of the first signal contact grooves  23  and is press-fit into one of the first signal contact grooves  23  (i.e., fixed in the housing  10 ). The lead portion  32  extends downward from the lower end of the anchoring portion  31  and protrudes downward out of the housing  10 . The first arm portion  33  extends upward from the upper end of the anchoring portion  31 , and the second arm portion  34  extends bending forward from the upper end of the first arm portion  33 . At the forward end of the second arm portion  34 , a contacting portion  35  is provided curling upward. This contact portion  35  protrudes forward beyond the front surface of the central raised portion  15 . Because the width of the first and second arm portions  33  and  34  is narrower than that of the signal contact grooves  21 , when a force is applied to the contact portions  35  from the front side of the connector, the contacts  30  bend elastically in the front and rear direction around the anchoring portions  31  in the signal contact grooves  21  and resist the force. 
     As shown in FIG. 7, each of the second signal-transmission contacts  40  comprises an anchoring portion  41 , a lead portion  42 , a first arm portion  43 , and a second arm portion  44 . The anchoring portion  41  has a width wider than that of the second signal contact grooves  24  and is press-fit into one of the second signal contact grooves  24  (i.e., fixed in the housing  10 ). The lead portion  42  extends downward from the lower end of the anchoring portion  41  and protrudes downward out of the housing  10 . The first arm portion  43  extends upward from the upper end of the anchoring portion  41 , and the second arm portion  44  extends bending forward from the upper end of the first arm portion  43 . At the forward end of the second arm portion  44 , a contacting portion  45  is provided curling upward. This contact portion  45  protrudes forward beyond the front surface of the central raised portion  15 . Because the width of the first and second arm portions  43  and  44  is narrower than that of the signal contact grooves  21 , when a force is applied to the contact portions  45  from the front side of the connector, the contacts  40  bend elastically in the front and rear direction around the anchoring portions  41  in the signal contact grooves  21  and resist the force. As shown in FIG. 7, the second arm portions  44  of the second signal-transmission contacts  40  are positioned above the second arm portions  34  of the first signal-transmission contacts  30 , both second arm portions protruding forward as described above. In this condition, the first and second signal-transmission contacts  30  and  40  are fixed in the signal contact grooves  21  without interfering each other while their contact portions  35  and  45  are aligned in pairs of upper and lower contact portions. 
     As shown in FIG. 7, each of the power-supply contacts  50  comprises an anchoring portion  51 , a lead portion  52 , an arm portion  53 , and a contact portion  54 . The anchoring portion  51  has a width wider than that of the power contact mounting grooves  25  and is press-fit into one of the power contact mounting grooves  25  (i.e., fixed in the housing  10 ). The lead portion  52  extends rearward and then downward from the lower end of the anchoring portion  51  and protrudes downward out of the housing  10 . The arm portion  53  extends obliquely rearward and downward from the upper end of the anchoring portion  51  and then extends obliquely rearward and upward. The contact portion  54  extends obliquely forward and upward from the upper end of the arm portion  53 . The forward end of the contact portion  54  protrudes upward beyond the upper surface of the plate-like portions  19  in the groove  14 . Because the width of the arm portions  53  and the contact portions  54  is narrower than that of the power contact grooves  22 , when a force is applied to the contact portions  54  from the upper side of the connector, the contacts  50  bend elastically in the up and down direction around the anchoring portions  51  in the power contact grooves  22  and resist the force. 
     For mounting the first and second signal-transmission contacts  30  and  40  into the housing  10 , firstly the second signal-transmission contacts  40  are inserted into the signal contact grooves  21  from the lower end of the housing  10 , and the anchoring portions  41  of the contacts  40  are press-fit into the second signal contact grooves  24 . Secondly, the first signal-transmission contacts  30  are mounted into the housing  10  in the same way by press-fitting the anchoring portions  31 . For mounting the power-supply contacts  50  into the housing  10 , the power-supply contacts  50  are inserted into the power contact grooves  22  from the lower end of the housing  10 , and the anchoring portions  51  are press-fit into the power contact mounting grooves  25 . In this way, the first and second signal-transmission contacts  30  and  40  and the power-supply contacts  50  are stitched into respective grooves all from the lower end of the housing  10 . As described previously, the signal contact grooves  21  and the power contact grooves  22  are continuous to the slits  20 , so the spaces of the slits  20  facilitates the mounting of the contacts  30 ,  40  and  50 , which are inserted into the respective grooves  21  and  22 . 
     As shown in FIG. 1, each of the locking mechanisms  60  comprises a fitting  61  and a releasing lever  62 , which is mounted on the upper part of the fitting  61 . The fittings  61  of the locking mechanisms  60  are fixed in the upper portions of the lateral arms  13 , one locking mechanism for each arm. As shown in FIG. 1A, tabs  61   a  are provided extending inward and rearward at the upper parts of the fittings  61 , which are bent forward. 
     The above described connector  1  is mounted vertically onto a printed circuit board (not shown), which is placed horizontally. The lead portions  32  and  42  of the first and second signal-transmission contacts  30  and  40  and the lead portions  52  of the power-supply contacts  50 , which protrude downward, are inserted downward into corresponding through-holes which are provided on the printed circuit board. The through-holes are formed perpendicular to the printed circuit board and are plated with a metal. The lower ends of the lead portions  32 ,  42  and  52 , which are in the through-holes, are then soldered onto the terminals of electrically conductive pathways of circuits which are provided on the lower surface of the printed circuit board. For the positioning of the connector  1  on the printed circuit board, positioning pins  26  are provided protruding downward on the lower surface of the housing  10  directly below the lateral arms  13 , and these positioning pins are inserted into the holes which are provided on the printed circuit board for the positioning of the connector. 
     The above described miniature card  70  is releasably installed into this connector  1 . In the installation of the miniature card  70  into the connector  1 , firstly, the miniature card  70  is tilted and oriented such that the upper end thereof is positioned forward and the first and second grooves  72  and  73  thereof are facing the first and second protrusions  17  and  18 , respectively, of the housing  10  of the connector. Secondly, the lower end  70   a  of the miniature card  70  is inserted into the groove  14  of the connector (refer to FIG.  8 ). During the insertion, the three power-supply contacts  71  of the miniature card  70 , which contacts are provided at the lower end  70   a , meet and push the three power-supply contacts  50  of the connector  1  downward. The position of the miniature card  70  in this condition, where the lower end  70   a  of the miniature card  70  is in the groove  14  of the housing  10  of the connector, is hereinafter referred to as “inserted position”. FIG. 2A shows this inserted position. The tilting angle of the miniature card  70  (i.e., the angle to the vertical line) which is required for the insertion of the lower end  70   a  of the miniature card  70  into the groove  14  of the connector  1  is defined in a range between 20 and 25 degrees. If the tilting angle of the miniature card  70  is less than 20 degrees, then the lower end  70   a  of the miniature card  70  hits the central raised portion  15  or the front wall  12  of the housing  10  of the connector. On the other hand, if it is greater than 25 degrees, then the lower end  70   a  of the miniature card  70  does not go into the groove  14  of the connector (FIG. 9 shows the condition where the tilting angle is 40 degrees). 
     Then, the miniature card  70  is turned around the lower end  70   a  thereof from the above described inserted position into a vertical position by pushing the surface  70   c  of the miniature card  70  in the direction indicated by an arrow in FIG.  2 . When the miniature card  70  comes close to the vertical position, the signal-transmission contacts  75  of the miniature card  70  meet and push the contact portions  35  and  45  of the first and second signal-transmission contacts  30  and  40  of the connector rearward. As a result, the first and second signal-transmission contacts  30  and  40  are deformed elastically rearward and acquire resiliency in the signal contact grooves  21 , which resiliency generates reaction forces in the contacts whose contact portions are in contact with the corresponding contacts of the miniature card  70 . In this condition, the lower end  70   a  of the miniature card  70  is pushed forward by the reaction forces, but it is held stationary by the rear surface of the front wall  12  of the housing  10  of the connector. Therefore, the miniature card  70  is turned further into the vertical position relatively easily against the resistance of the first and second signal-transmission contacts  30  and  40 . In this condition, the front wall  12  of the housing is pushed forward by the lower end  70   a  of the miniature card  70 , but the front wall  12  has a strength which is sufficient to withstand this pressure because it is connected firmly to the rear wall  11  of the housing  10  through the lateral arms  13  and the plate-like portions  19 . 
     When the miniature card  70  is pushed further against the resistance of the first and second signal-transmission contacts  30  and  40 , the lateral sides of the upper part of the miniature card  70  meet the tabs  61   a  of the locking mechanisms  60 . As described previously, because the tabs  61   a  extend inward and rearward, when the miniature card  70  is pushed further, the tabs  61   a  (together with the releasing levers  62 ) are opened laterally outward by the lateral ends of the miniature card  70 . When the miniature card  70  becomes substantially parallel with the rear wall  11  of the housing  10  (i.e., when it is almost vertical), the lateral recesses  76  of the miniature card  70  fit with the lateral raised portions  16  of the housing  10 . At the same time, the tabs  61   a  of the locking mechanisms  60  are freed from the lateral ends of the miniature card  70  to come onto the surface  70   c  of the miniature card  70  because of the resiliency of the fittings  61  of the locking mechanisms  60 . As a result, the miniature card  70  is held and locked by the locking mechanisms  60 , and the installation of the miniature card  70  is complete. This position of the miniature card  70  in the housing  10  of the connector  1 , which is shown in FIG. 2B, is hereinafter referred to as “installed position”. In the installed position, the power-supply contacts  71  of the miniature card  70  are in contact with the power-supply contacts  50  of the connector  1 , and the signal-transmission contacts  75  of the miniature card  70  are in contact with the first and second signal-transmission contacts  30  and  40  of the connector  1 . In this condition, the miniature card  70  is ready for information exchange through the connector  1 . 
     As described above, in the connector  1  according to the present invention, a plurality of signal-transmission contacts (i.e., a first signal-transmission contact  30  and a second signal-transmission contact  40 ) are mounted in each contact groove  21 , so the contact grooves  21  are provided in the housing  10  in a relatively small number. This construction of the housing simplifies the design of a metal mold which is used for forming the housing. Also, in the connector  1  according to the present invention, all the signal-transmission contacts are mounted into the housing from the one side (i.e., the lower side) of the housing, so the contacts are mounted in the housing relatively easily. Furthermore, in the connector of the present invention, the first and second signal-transmission contacts  30  and  40  are not configured in a Z shape as required for a conventional connector. Therefore, the first and second signal-transmission contacts  30  and  40  can be produced in a large number in a lot, respectively, from a plate material. Thus, the number of manufacturing steps can be reduced to improve the productivity. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. 
     RELATED APPLICATIONS 
     This application claims the priority of Japanese Patent Application No.10-352634 filed on Dec. 11, 1998, which is incorporated herein by reference.