Patent Publication Number: US-2005142922-A1

Title: Electrical connector assembly

Description:
FIELD OF THE INVENTION  
      The invention relates to an electrical connector assembly and, more particularly, to an electrical connector assembly having a first connector and a second connector that each have contacts with convex projecting portions and housings with protective lips for preventing damage to contact portions of the contacts.  
     BACKGROUND OF THE INVENTION  
      Electrical connector assemblies are commonly made with mating contacts having contact portions with the same shape in order to reduce manufacturing costs, ease control of contact force, lower mating force, etc. One example of such an electrical connector assembly is shown in  FIGS. 8-9  and disclosed in Japanese Patent Laid-Open No. 2-49373.  
      As shown in  FIG. 8 , the electrical connector assembly includes a first connector  80  and a second connector  90 . As shown in Part (A) of  FIG. 8 , the first connector  80  includes a housing  82  having a contact  81 . The contact  81  has a contact portion  81 , a press-fit portion  812 , and a terminal (not shown). The press-fit portion  812  is press-fit into the housing  82 . Between the contact portion  811  and the press-fit portion  812 , the contact  81  has a fixed section  813 . The fixed section  813  is fixed along an inner wall of the housing  82 .  
      The contact portion  811  and the fixed section  813  of the contact  81  are disposed in an interior of an opening  821  formed in the housing  82 . The contact portion  811  is positioned between the opening  821  and a cavity  822 . The contact portion  811  is fixed in a position adjacent to the cavity  822  such that the contact portion  811  enters the cavity  822  upon engagement with the second connector  90 . The terminal (not shown) is connected to a substrate (not shown). The housing  82  of the first connector  80  may be fabricated by use of a split mold capable of being divided in a vertical direction of Part (A) of  FIG. 8 .  
      As shown in Part (B) of  FIG. 8 , the second connector  90  includes a housing  92  having a contact  91 . The contact  91  has a contact portion  911 , a press-fit portion  912 , and a terminal (not shown). The press-fit portion  912  is press-fit into the housing  92 . Between the contact portion  911  and the press-fit portion  912 , the contact  91  has a fixed section  913 . The fixed section  913  is fixed along an inner wall of the housing  92 . The contact portion  911  of the contact  91  has the same shape as the contact portion  811  of the contact  81  shown in Part (A) of  FIG. 8 .  
      The contact portion  911  and the fixed section  913  are arranged in an interior of an opening  921  formed in the housing  92 . The contact portion  911  is positioned between the opening  921  and a cavity  922 . The cavity  922  is formed adjacent to the contact portion  911  such that the cavity  922  receives the contact portion  911  upon engagement with the first connector  80 . The terminal (not shown) is connected to a substrate (not shown). The housing  92  is fabricated by use of a split mold capable of being divided in a vertical direction of Part (B) of  FIG. 8 .  
      As shown in  FIG. 9 , when the first connector  80  and the second connector  90  are mated, the contact portion  811  of the contact  81  of the first connector  80  comes into contact with the fixed section  913  of the contact  91  of the second connector  90  and the contact portion  911  of the contact  91  of the second connector  90  comes into contact with the fixed section  813  of the contact  81  of the first connector  80 . The fixed sections  813 ,  913  of the contacts  81 ,  91  are disposed along the inner walls of the respective housings  82 ,  92  such that the positions of the fixed sections  813 ,  913  are fixed. As a result, the contact portions  911 ,  811  and not the fixed sections  813 , deform when the contact portions  911 ,  811  come into contact with the fixed sections  813 ,  913 . Because contact occurs between an elastic part and an inelastic part, the electrical contact between the two contacts  81 ,  91  is stable.  
      Because the contact portions  811 ,  911  of the contacts  81 ,  91  in the first connector  80  and the second connector  90  are unprotected in an unmated state, there is a possibility that something might come into contact with leading ends of the contact portions  811 ,  911 , which may cause deformation of the contact portions  811 ,  911 . Additionally, when the first connector  80  and the second connector  90  are mated, there is a possibility that either the first connector  80  or the second connector  90  might come into contact with the leading ends of the contact portions  811 ,  911 , which may also cause deformation of the contact portions  811 ,  911 .  
      To prevent the leading ends of the contact portions  811 ,  911  from being damaged, protective lips (not shown) may be formed of the housings  82 ,  92  near the leading ends of the contact portions  811 ,  911  of the contacts  81 ,  91 . Forming the protective lips (not shown) on the housings  82 ,  92  of the first connector  80  and the second connector  90 , however, will make it impossible to fabricate the housings  82 ,  92  with a simple split mold, which will increase manufacturing costs.  
     SUMMARY OF THE INVENTION  
      It is therefore an object of the invention to provide an inexpensive electrical connector assembly that includes a first connector and a second connector that each have similarly formed contacts and housings with protective lips for preventing damage to contact portions of the contacts.  
      This and other objects are achieved by an electrical connector assembly comprising a first connector and a second connector. The first connector and the second connector each have a housing with a contact receiving wall. Contacts are disposed in the housings of the first and second connectors. Each of the contacts has a contact portion, a terminal, a convex projection, and a press-fit portion. The convex projection is arranged between the contact portion and the press-fit portion. The convex projection abuts the contact receiving wall in the housing in which the contact is disposed to space the contact from the contact receiving wall when the first and second connectors are mated. A protective lip is formed on the contact receiving walls of the first and second connectors. The protective lip is formed adjacent to the contact portions of the contacts.  
      This and other objects are further achieved by a connector comprising a housing having a contact receiving wall. Contacts are disposed in the housing. Each of the contacts has a contact portion, a terminal, a convex projection, and a press-fit portion. The convex projection is arranged between the contact portion and the press-fit portion. The convex projection abuts the contact receiving wall to space the contact from the contact receiving wall. A protective lip is formed on the contact receiving wall adjacent to the contact portions of the contacts. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of a first connector of an electrical connector assembly according to an embodiment of the invention;  
       FIG. 2  is a perspective view of a second connector of the electrical connector assembly according to an embodiment of the invention;  
       FIG. 3  is a schematic sectional view of a connecting plate of a grounding member soldered to a substrate;  
       FIG. 4  is a sectional view of the first connector of  FIG. 1  mated with the second connector of  FIG. 2 ;  
       FIG. 5  is another sectional view of the first connector of  FIG. 1  mated with the second connector of  FIG. 2 ;  
       FIG. 6  is a perspective view of a contact of the first connector of  FIG. 1  and a contact of the second connector of  FIG. 2 ;  
       FIG. 7  is an explanatory drawing of a method of forming convex projections on the contacts;  
       FIG. 8  is a sectional view of a conventional electrical connector assembly disclosed in Japanese Patent Laid-Open No. 2-49373; and  
       FIG. 9  is another sectional view of the conventional electrical connector assembly disclosed in Japanese Patent Laid-Open No. 2-49373. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       FIG. 1  shows a first connector  10  and  FIG. 2  shows a second connector  20 . The first connector  10  and the second connector  20  form an electrical connector assembly according to the invention. As shown in  FIG. 1 , the first connector  10  consists of a housing  13  having an outer wall  131  and a contact receiving wall  132 . The outer wall  131  forms an outer perimeter of the housing  13 . The contact receiving wall  132  stands on an inner side of the outer wall  131  and defines an opening  133 . As shown in  FIG. 4 , a top edge of the contact receiving wall  132  has a protective lip  134  extending toward the outer wall  131 .  
      As shown in  FIG. 1 , contacts  11  are disposed in a first row  11   a  and a second row  11   b  in the housing  13 . As shown in  FIG. 6 , each of the contacts  11  has a contact portion  111 , a convex projection  112 , a press-fit portion  113 , and a terminal  114 . The press-fit portions  113  are press-fit into the housing  13  such that the press-fit portions  113  spread in a direction of width (i.e., in a direction perpendicular to  FIGS. 4-5 ) and are fixed into a wall that faces the direction perpendicular to  FIGS. 4-5 . As shown in  FIG. 1 , the contact portion  111  is arranged on an outer side of the contact receiving wall  132 . As shown in  FIG. 4 , the convex projection  112  abuts against the outer side of the contact receiving wall  132  of the housing  13  of the first connector  10  to keep the contact portion  111  spaced from the contact receiving wall  132 . The terminal  114  extends laterally and projects from a bottom surface of the housing  13  and is surface mounted or otherwise connected to a substrate  30  ( FIG. 3 ).  
      As shown in  FIG. 1 , the housing  13  has a grounding member  12  shaped in the form of the letter U when viewed from a side thereof. The grounding member  12  includes a first grounding plate  121  and a second grounding plate  122 . The first grounding plate  121  is arranged in a vicinity of the first row  11   a  of contacts  11 , and the second grounding plate  122  is arranged in a vicinity of the second row  11   b  of contacts  11 . The first and second grounding plates  121 ,  122  each have grounding contacts  124  formed by blanking and bending. A connecting plate  123  connects the first grounding plate  121  and the second grounding plate  122 . The connecting plate  123  has a plurality of slots  125  and is disposed in the opening  133  of the housing  13  such that the first grounding plate  121  and second grounding plate  222  are held on the inner side of the contact receiving wall  132  of the housing  13 . Because the first and second grounding plates  121 ,  122  are supported by the contact receiving wall  132  of the housing  13 , the grounding member  12  of the first connector  10  may be formed from a thin plate material.  
      As shown in  FIG. 3 , the connecting plate  123  is surface mounted on a substrate  30  on which the first connector  10  is mounted. The connecting plate  123  is mounted to the substrate  30  with solder  31  such that peripheral edges of the slots  125  are soldered to the substrate  30 . Because the peripheral edges of the slots  125  are soldered to the substrate  30 , the connecting plate  123  is securely attached to the substrate  30 . Additionally, because the slots  125  are arranged in the opening  133 , it is possible to visually check the condition of the soldering.  
      As shown in  FIG. 2 , the second connector  20  consists of a housing  23  having a contact receiving wall  231 . The contact receiving wall  231  forms an outer perimeter of the housing  23 . As shown in  FIG. 4 , a top edge of the contact receiving wall  231  has a protective lip  233 . As shown in  FIG. 2 , in a middle of the region enclosed by the contact receiving wall  231  is an opening  232  that extends in a longitudinal direction.  
      Contacts  21  are disposed in a first row  21   a  and a second row  21   b  in the housing  23 . As shown in  FIG. 6 , each of the contacts  21  has a contact portion  211 , a convex projection  212 , a press-fit portion  213 , and a terminal  214 . The press-fit portions  213  are press-fit into the housing  23  such that the press-fit portions  213  spread in a direction of width (i.e., in a direction perpendicular to  FIGS. 4-5 ) and are fixed into a wall that faces the direction perpendicular to  FIGS. 4-5 . As shown in  FIG. 2 , the contact portion  211  is arranged on an inner side of the contact receiving wall  231  of the housing  23 . The contact portion  211  of the contact  21  of the second connector  20  has the same shape as the contact portion  111  of the contact  11  of the first connector  10  shown in  FIG. 1 . As shown in  FIG. 4 , the convex projection  212  of the second connector  20  abuts against the inner side of the contact receiving wall  231  of the housing  23  of the second connector  20  to keep the contact portion  211  spaced from the contact receiving wall  231 . The terminal  214  extends laterally and projects from a bottom surface of the housing  23  and is surface mounted or otherwise connected to a substrate (not shown).  
      As shown in  FIG. 2 , the housing  23  has a grounding member  22  shaped in the form of the letter U when viewed from a side thereof. The grounding member  22  includes a first grounding plate  221  and a second grounding plate  222 . The first grounding plate  221  is arranged in a vicinity of the first row  21   a  of contacts  21 , and the second grounding plate  222  is arranged in a vicinity of the second row  21   b  of contacts  21 . A connecting plate  223  connects the first grounding plate  221  and the second grounding plate  222 . The connecting plate  223  has a plurality of slots  224  and is disposed in the opening  232  of the housing  23  of the second connector  20  such that the grounding member  22  is held by the housing  23 . Because the first and second grounding plates  221 ,  222  of the first connector  20  stand alone, the grounding member  23  is supported by the rigidity of the grounding member  22  itself. Therefore, the grounding member  22  of the second connector  20  is formed from a thicker plate material having a larger rigidity than the grounding member  12  of the first connector  10  shown in  FIG. 1 . Because the grounding member  22  of the second connector  20  has a large enough rigidity to enable the grounding member  22  to stand alone, it is unnecessary to form a wall to support the first and second grounding plates  221 ,  222  of the grounding member  22 . As a result, it is possible to minimize the size of the electrical connector assembly in a direction of width while maintaining the visibility of the connecting plates  123 ,  223 .  
      The connecting plate  223  is surface mounted on a substrate (not shown) on which the second connector  20  is mounted in a manner similar to the connecting plate  123  of the first connector  10  shown in  FIG. 3 . The connecting plate  223  of the second connector  20  therefore has the same advantages as the connecting plate  123  of the first connector  10 .  
       FIG. 7  is an explanatory drawing of a method of forming the convex projections  212  of the contacts  21  of the second connector  20 . Because the convex projections  112  of the contacts  11  of the first connector  10  are formed in the same manner, a description thereof will be omitted. As shown in Part (A) of  FIG. 7 , projecting pieces  2121 ,  2122  extend in a direction of width and are formed by blanking a metal plate. The projecting pieces  2121 ,  2122  are then bent in a direction of the arrows shown in Part B) of  FIG. 7  and an inward force is applied to form the convex projection  212 .  
       FIGS. 4-5  show the first connector  10  mated with the second connector  20 . During mating, the contact portions  111  of the contacts  11  of the first connector  10  and the contact portions  211  of the contacts  21  of the second connector  20  are elastically deformed such that the contact portions  111 ,  211  come into electrical contact with each other with a prescribed contact pressure that keeps the contact portions  111 ,  211  electrically connected. The surface of the contact portions  111 ,  211  that contact each other is a rolled surface formed from a surface of a flat metal plate. This surface is a smooth surface, which decreases the mating force and provides high contact reliability. The contact portions  111  of the contacts  11  of the first connector  10  and the contact portions  211  of the contacts  21  of the second connector  20  come into contact in a vicinity of the convex projections  212 ,  112 . Because the convex projections  212 ,  112  are fixed in position by the respective housings  13 ,  23 , contact between the contacts  11  of the first connector  10  and the contacts  21  of the second connector  20  is stable.  
      Also during mating, the grounding contact  124  of the first connector  10  interferes with the first and second grounding plates  221 ,  222  of the second connector  20  such that the grounding contact  124  of the first connector  10  is elastically deformed into contact with the first and second grounding plates  221 ,  222  of the second connector  20 . The grounding contact  124  of the first connector  10  contacts the first and second grounding plates  221 ,  222  of the second connector  20  with a prescribed contact pressure. The grounding contact  124  of the first connector  10  is formed in such a manner that a portion of the grounding contact  124  of the first connector  10  is hidden behind the first and second grounding plates  221 ,  222  of the second connector  20 .  
      As shown in  FIG. 5 , a first wall is formed close to the first rows  11   a ,  21   a  of contacts  11 ,  21  by the first grounding plates  121 ,  221  of the first connector  10  and the second connector  20 , and a second wall is formed close to the second rows  11   b ,  21   b  of contacts  11 ,  21  by the second grounding plates  122 ,  222  of the first connector  10  and the second connector  20 . The first and second walls serve to suppress crosstalk and thereby provide a structure suitable for high-speed signal transmission.  
      As shown in  FIG. 4 , the protective lip  134  formed on the contact receiving wall  132  of the housing  13  of the first connector  10  protects leading ends of the contact portions  111  of the contacts  11  of the first connector  10 . Because there is no other projecting portion than the protective lip  134  on the outer side of the contact receiving wall  132 , it is possible to fabricate the housing  13  by use of a split mold capable of being divided in a vertical direction of  FIG. 4 . Similarly, the protective lip  233  formed on the inner side of the contact receiving wall  231  of the housing  23  of the second connector  20  protects leading ends of the contact portions  211  of the contacts  12  of the second connector  20 . Because there is no other projecting portion than the protective lip  233  on the inner side of the contact receiving wall  231 , it is possible to fabricate the housing  23  by use of a split mold capable of being divided in the vertical direction of  FIG. 4 .  
      Because the convex projections  112 ,  212  are provided on the contacts  11 ,  21  of the first connector  10  and the second connector  20  and the protective lips  134 ,  233  are provided on the housings  13 ,  23  of the first connector  10  and the second connector  20 , it is possible to protect the leading ends of the contact portions  111 ,  211  of the contacts  11 ,  21  of the first connector  10  and the second connector  20  without increasing costs. Additionally, because the contact portions  111 ,  211  come into contact within the vicinity of the convex projections  112 ,  212  upon engagement, contact occurs between an elastic portion of the contacts  11 ,  21  and an inelastic portion of the contacts  11 ,  21 , which provides a stable electrical connection. Additionally, the convex projections  112 ,  212  are not deformed because the convex projections  112 ,  212  are in abutment with the respective housings  13 ,  23 . The convex projections  112 ,  212  therefore perform the same role as the fixed sections of the contacts of the conventional electrical connector assembly shown in  FIGS. 8-9 .