Patent Publication Number: US-7217158-B2

Title: Electrical connector

Description:
This is a division of application Ser. No. 10/959,337, filed Oct. 7, 2004, now U.S. Pat. No. 7,004,792. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to electrical connectors and, particularly, to an electrical connector to be attached to a circuit board. 
   2. Description of the Related Art 
   JP 05-94847 discloses an electrical connector of this type. The connector includes a board connector to be attached to a circuit board and an external connector to be plugged to the connector in a direction parallel to the circuit board. The board connector includes a tubular shield case and a housing spaced within the shield case and having an arranging plate in the back side of which the contact sections of terminals are arranged. The external connector includes a housing with a receiving cavity for receiving the arranging plate and a shield case surrounding the housing. The U-shaped contact sections of terminals are provided in the receiving cavity for pressing the arranging plate upon plugging. 
   There is a strong demand for miniaturization of electronics devices, especially, low-profile electronics components including electrical connectors. The afore-mentioned electrical connector, however, failed to meet the low-file requirement. The connector on a circuit board must have a receiving space around the arranging plate for receiving a mating connector and the mating connector must have a projection section with a receiving cavity for receiving the arranging plate, resulting in the high-profile connectors. 
   SUMMARY OF THE INVENTION 
   Accordingly, it is an object of the invention to provide a low-profile connector to be mounted on a circuit board. 
   The invention relates to an electrical connector comprising a housing having an outer wall with at least one arranging section at a predetermined interval and at least one terminal having a contact section provided in the arranging section and brought into contact with a contact section of a mating connector upon plugging operation. 
   According to the invention, the arranging section is provided in an inner side of the outer wall of the housing. There is no wall corresponding to the outer wall so that the height of the connector is reduced by the thickness of another wall. 
   The electrical connector is a receptacle connector provided on a circuit board for receiving a mating connector in a direction parallel to the circuit board or a plug connector to be connected to a receptacle connector in a direction parallel to a circuit board on which the receptacle connector is provided. 
   The contact section of the terminal is raised from the arranging section and is made flexible or fixed closely to a bottom of the arranging section. For the fixed contact section, the arranging section is an arranging groove having a depth sufficiently deep to house the contact section therein so that no finger or the like can touch the contact section accidentally. 
   The electrical connector further comprises a shield case for covering the housing so as to facilitate guiding and supporting the mating connector. The shield sheet is so thin that its thickness hardly affects the height. 
   The housing includes a housing body and a holding member to form a retention section for retaining an intermediate portion of the terminal, the housing body having a retention groove communicating with the arranging groove. This structure eliminates the difficult task that a curved terminal is inserted into an aperture in the housing. 
   According to the invention, the contact section of a terminal is arranged on a single wall of a housing so that no opposed wall is required, thus minimizing the height of the connector. The shield case, which is made of a metal sheet and provided on the housing, working as an opposed wall to the single wall, not only hardly increases the height of the connector but also facilitates the plugging of a mating connector. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a sectional view of a receptacle connector and a plug connector according to the first embodiment of the invention; 
       FIG. 2  is a perspective view of the receptacle connector; 
       FIG. 3  is a exploded perspective view of the receptacle connector; 
       FIG. 4(A)  is a perspective view of the plug connector; 
       FIG. 4(B)  is a sectional and perspective view of the contact section of a terminal; 
       FIG. 5  is a plan view of the front portion of a shield case for the plug connector; 
       FIG. 6  is a sectional view of a receptacle connector and a plug connector according to the second embodiment of the invention; 
       FIG. 7(A)  is a perspective view of a portion of a terminal for the receptacle connector of  FIG. 6 ; 
       FIG. 7(B)  is a perspective view of the arranging grooves of a housing for the receptacle connector of  FIG. 6 ; and 
       FIG. 8  is a sectional view of a receptacle connector according to a variation of the second embodiment. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Embodiments of the invention will now be described below with reference to the accompanying drawings. 
   First Embodiment 
   In  FIGS. 1–4 , a receptacle connector  20  is attached to the edge of a circuit board P so as to receive a plug connector  30 . The receptacle connector  20  has an opening for receiving the plug connector  30  in a direction parallel to the circuit board P. The receptacle connector  20  includes a terminal  1 , a housing  2 , and a shield case  3 . 
   The terminal  1  is made by bending a strip of metal to provide a front contact section  4  and a rear connection section  5 . The contact section  4  is made by folding back the front portion of the terminal  1  and then raising its tip obliquely upwardly with the rear end rounded. The connection section  5  is made by bending the rear portion downwardly and then horizontally for contact with the circuit board. 
   The housing  2  is made of an insulative material, such as a plastic, so as to provide a housing body  6  and a holding member  7 . The housing body  6  includes an arranging plate  9  in which a plurality of parallel arranging grooves  8  are provided and a pair of fixing blocks  10  provided on opposite rear ends of the arranging plate  9  ( FIG. 3 ). Each arranging groove  8  extends from the front edge  9 A to the rear end of the arranging plate  9 . The arranging groove  8  has a depth sufficiently deep to accommodate the terminal  1  but the resilient U-shaped contact section  4  projects upwardly from the arranging groove  8 . A pair of indentations  9 B extend along opposite lower sides of the arranging plate  9 . The fixing block  10  extends upwardly and laterally from the arranging plate  9  and has a vertical guiding groove  10 A in the inner side thereof. 
   The holding member  7  fits in a space between the fixing blocks  10  so as to be flat with the fixing blocks  10 . A pair of vertical guided projections  7 A are provided on opposite sides of the holding member  7  to be guided by the guiding grooves  10 A. The lower ends of the guided projections  7 A are tapered so as to facilitate insertion into the guiding grooves  10 A. A plurality of projections  7 B are provided on the lower face of the holding member  7  so as to fit in the respective arranging grooves  8  to retain the terminals without failure. Consequently, the arranging grooves  8  work as holding grooves in the range corresponding to the holding member  7 . Thus, it is possible to fix to the housing the terminals that have a U-shaped front and a crank-shaped rear portions and have been impossible to insert into terminal apertures. The U-shaped contact sections of short terminals are able to provide satisfactory contact forces. 
   The shield case  3  is made by bending and forming a metal sheet to provide an upper face  3 A, side faces  3 B, and lower faces  3 C so as to cover the top of the holding member  7 , the sides of the fixing blocks  10 , and the lower edges of the housing  2 . The lower faces  3 C of the shield case  3  fit in the indentations  9 B of the arranging plate  9  so that not only the height of the connector is reduced by the thickness of the lower face  3 C but also the arranging plate is reinforced. When the shield case  3  is attached to the housing  2 , it forms an inner receiving space  21  above the arranging grooves  8  and to the sides of the arranging plate  9  for receiving a mating connector. 
   A pair of lock holes  3 D are provided in the top face  3 A of the shield case  3  for engagement with locks of the plug connector  30  as described hereinafter. 
   The terminal  1  is placed in the arranging groove  8  of the housing body  6 , and the holding member  7  is placed between the fixing blocks  10  such that the guided projections  7 A are guided by the guiding grooves  10 A of the fixing blocks  10 . The projections  7 A of the holding member  7  fit in the arranging grooves  8  to firmly hold the terminals  1  in the arranging grooves  8 . Then, the shield case  3  is attached to the housing  2  so as to cover the housing body  6 , the fixing blocks  10 , and the holding member  7 . 
   The plug connector  30  includes a housing  31 , terminals  32 , a shield case  33 , and a cover case  34 . The housing  31  is made of an insulative material, such as a plastic, to provide a terminal retention section  35  and a plugging section  36  having a plate shape thinner than the terminal retention section  35  and extending forwardly from the terminal retention section  35 . The terminal retention section  35  is molded together with the terminals  32  so as to hold the intermediate sections. As  FIGS. 4(A)  and (B) show, the plugging section  36  has a plurality of grooves  37  for guiding the contact sections  4  of terminals  1 . The fixed contact sections  32 A of the terminals  32  are closely attached to the bottoms of the grooves  37 . The crank-shaped portions of the terminals  32  are retained by the terminal retention section  35  alternately up/down positions so that the rear connection sections  32 B are arranged in two tiers. The front ends  32 C of the terminals  32  are embedded in the housing to avoid collision with a mating connector. The contact sections  32 A of the terminals  32  are located inside the grooves  37  so that no finger or the like can touch them easily. 
   The shield case  33  is fitted over the housing  31 . As  FIG. 4(A)  shows, it covers the upper half of the terminal retention section  35  and the plugging section  36  except for the lower intermediate section (which corresponds to the arranging plate  9  of the receptacle connector  20 ). A pair of projections  33 A are provided on the shield case  33  for engagement with the lock holes  3 D of the receptacle connector  20 . As  FIG. 5  shows, each project  33 A is made by raising the center of a resilient strip  33 C which is formed by a pair of grooves  33 B so that it makes resilient movement upon engagement/disengagement with the lock hole  3 D. Then, the upper and lower halves of the cover case  34  are attached to the housing  31  equipped with the shield case  33  as shown in  FIG. 1 . The projection  33 A is widened to the size of the lock hole  3 D to increase the locking power. Consequently, the groove  33 B is curved outwardly at the position of the projection  33 A. 
   The plugging section  36  of the plug connector  30  is plugged into the receptacle connector  20  provided on the circuit board P such that the terminal contact sections  4  of the receptacle connector  20  are brought into resilient contact with the fixed terminal contact sections  32 A of the plug connector  30 . The two connectors have only one outer wall in the plugging area so that the height of the plugged connectors becomes small. The shield case is made of a metal sheet which is so thin that it does not affect the height. 
   Second Embodiment 
   The second embodiment in  FIG. 6  has an opposite structure of the terminal contact sections of the receptacle connector  20  and the terminal contact sections of the plug connector of the first embodiment in  FIG. 1 . Hence, the terminal contact sections  4  of the receptacle connector  20  are fixed and the terminal contact sections  32 A of the plug connector  30  are resilient. Each terminal contact section  32 A has a front tip supported by the supporting portion  38  of the housing with a biasing force so that it is not only flexible upwardly upon plugging into the receptacle connector  20  but also stable when the plug connector  30  is not plugged into the receptacle connector  20 . 
   As shown in  FIGS. 7(A)  and (B), the terminal  1  has a pair of engaging notches  1 A in the portion to be fitted into the arranging groove  8  of the housing body  6 , and the arranging groove  8  has a pair of engaging projections  8 A corresponding to the engaging notches  1 A to prevent longitudinal movement or separation of the terminal  1  from the arranging groove  8 . This structure may be used for the first embodiment. 
     FIG. 8  shows a variation of the second embodiment, wherein the housing of the receptacle connector  20  is inverted. A single outer wall of the housing constitutes the arranging plate  9  on which the contact section  4  is placed, thus minimizing the connector. Unlike the embodiment of  FIG. 1 , the housing is not divided into the housing body and the holding member but is made as a single member. The terminal is inserted into the insertion hole or molded integrally with the housing.