Abstract:
A connector of the engagement connection type using a plug and socket includes at least a plug pin for the plug and a socket terminal for the socket on one side. A projection of at least one of the plug pin and socket terminal projects toward a connection surface of the other one of the plug pin and socket terminal. The projection is affixed to elastic contact arm that exerts an elastic force toward a contact surface of the other one of the plug pin and socket terminal.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims priority from Japanese Patent Application No. 2007-203660, which was filed on Aug. 3, 2007, and is hereby incorporated by reference in its entirety herein. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to a connector for making an electrical connection, particularly a connector of a plug and socket engagement type as well as a connector terminal construction for the same. 
       BACKGROUND OF THE INVENTION 
       [0003]    For example, as shown in  FIG. 6(   a ), a connector for making an electrical connection has a plug pin  121  of a plug  120  that is inserted into a cylindrical socket terminal  111  of a socket  110  is public knowledge. 
         [0004]    With this type of connector, it is easy to insert the plug pin, and for the sake of stabilizing the electrical connection, the socket terminal is of a so-called bottle-shaped configuration. Typically, a notch  115  is formed in the cylindrical part in the insertion direction, and an elastic contact arm  116  is formed with the end expanding in diameter on the outer side. 
         [0005]    Accordingly, in order to ensure contact strength with the plug pin, there must be ample elastic displacement in the direction of the expanding diameter of the elastic contact arm  116 , but since the end part  116   b  has an expanding diameter going toward the end, there is a need to have a large space  117  between this and the housing  130  that insulates the terminal. For this to be made possible, the plug housing must also be expanded, making compactness of the connector difficult. 
         [0006]    In Published Unexamined Japanese Patent Application No. H10-116644, a technology is disclosed in which a protrusion provided within the socket terminal makes a point contact with the plug pin, but there is a large amount of dispersion with regard to the height of the protrusion, resulting in degradation of contact reliability. 
       SUMMARY OF THE INVENTION  
       [0007]    In light of the technological problems noted above, it is an object of the present invention to provide a contact terminal construction and a compact form of a connector based on this construction in which there is a high level of electrical connection reliability as well as effective compactness of the connector. 
         [0008]    The present invention is a connector of the engagement connection type using a plug and socket, in which there is, at the least, a plug pin for the plug and a socket terminal for the socket on one side, as well as a projection that projects toward the connection surface of the other side along with an elastic contact arm with an elastic force toward this connection surface of the other side. 
         [0009]    There are various types of plug pins used in plugs, including round plug pins with hemispherical end parts, as well as strip plugs and the like. 
         [0010]    On the other hand, there are also various types of socket terminals used in sockets, including cylindrical terminals, side-snap types and the like. 
         [0011]    The present invention has contact means through a projection on one side, between at least a plug pin of such a plug, or a socket terminal of such a socket, as well as contact means through an elastic arm. 
         [0012]    The invention is suitable for use in a cylindrical socket terminal in which a plug pin is inserted, having a protrusion on the inside of the cylindrical part of the socket terminal in which the plug pin is inserted. Further, this socket terminal has an elastic contact arm with an elastic force toward the inside, in which one part of the cylindrical part is formed by cutting along the engagement direction of the plug pin. 
         [0013]    In the present invention, since it is possible to make an electrical connection using two different types of contact means for the plug pins and socket terminals, namely, contact means through the use of a protrusion, and contact means through the use of an elastic arm, the amount of bending of the elastic arm via the contact means through the use of a protrusion can be held below that of a conventional bottle-shaped configuration, and moreover, the effects from contact dispersion due to the height dispersion of protrusions in the case of contact means through the use of an elastic arm can be reduced. Further, the reliability of the electrical connections is improved, and compared to the contacts in the conventional bottle-shaped configuration, the space between the housing and the end part of the socket terminal can be reduced, making it possible to provide compactness to the connector. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The invention will become more readily apparent from the Detailed Description on the Invention, which proceeds with reference to the drawings, in which 
           [0015]      FIG. 1(   a ) shows a side view of the plug pin and socket terminal prior to electrical connection; 
           [0016]      FIG. 1(   b ) shows a plan view of the plug pin and socket terminal; 
           [0017]      FIG. 1(   c ) shows an explanatory drawing of the plan view of the socket part in the state in which a cut is made corresponding to view A-A; 
           [0018]      FIG. 2(   a ) shows a side view of the plug pin and socket terminal after an electrical connection has been made; 
           [0019]      FIG. 2(   b ) shows a plan view of the plug pin and socket terminal; 
           [0020]      FIG. 2(   c ) shows an explanatory drawing of the plan view of the socket part in the state in which a cut is made corresponding to view A-A; 
           [0021]      FIGS. 3(   a ) and  3 ( b ) show the socket connector with the socket terminal installed in the socket housing, as well as the plug connector with the plug pin installed in the plug housing; 
           [0022]      FIG. 4(   a ) through  4 ( c ) show the plug part as it is inserted into the socket part; 
           [0023]      FIG. 5  shows a plan view of the plug pin that is equipped with an elastic contact arm and contact protrusion; and 
           [0024]      FIGS. 6(   a ) and  6 ( b ) provide explanatory drawings of a conventional terminal connection construction. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]    The following listing provides a key to the reference numerals and elements depicted in the drawings.
     1 : Electric line     2 : Core wire     10 : Socket terminal     11 : Socket part     12 : Cylinder part     13 : Insertion port     14 : Contact protrusion     15 : Slit part     16 : Elastic contact arm     16   a:  Flexible arm     16   b:  Slanted arm     16   c:  Contact point     17 : Lance     18 : Stabilizer     19 : Electric line connection part     20 : Plug pin     21 : Plug part     22 : Plug front end part     23 : Plug side surface part     24 : Lance     25 : Stabilizer     26 : Electric line connection part     30 : Socket housing     31 : Cylindrical receiver part     32 : Cylindrical insertion part     33 : Terminal storage chamber     34 : Inner wall of terminal storage chamber     35 : Guide groove     36 : Lance clip part     37 : Cylindrical concave part     40 : Plug housing     41 : Cylindrical plug-in part     42 : Cylindrical insertion part     43 : Terminal storage chamber     44 : Inner wall of terminal storage chamber     45 : Guide groove     46 : Lance clip part     50 : Socket connector     60 : Plug connector   
 
         [0065]    The following examples are used to describe a connector according to the present invention which is composed of a round plug pin and a cylindrical socket terminal, and as for the construction of the connector related to the present invention, it is possible to apply this to various connector types in which an engagement connection is made between a plug pin and socket terminal. 
         [0066]      FIG. 1(   a ) is a side view of a plug pin  20  and socket terminal  10  prior to the engagement connection, and  FIG. 1(   b ) is a plan view of the same.  FIG. 1(   c ) is a plan view of a cutaway corresponding to view A-A of a socket part  11  of the socket terminal  10 . 
         [0067]      FIG. 2(   a ) is a side view of the plug pin  20  and socket terminal  10  after the engagement connection, and  FIG. 2(   b ) is a plan view of the same.  FIG. 1(   c ) is a plan view of a cutaway corresponding to view A-A of the socket part of the socket terminal  10  in its engaged state. 
         [0068]    The socket terminal  10  is provided with an insertion port  13  for inserting the plug part  21  of the plug pin  20  into the end in the direction of engagement of the cylindrical socket part  11 , and the rear end of this socket terminal  10  has an electric line connection part  19 . 
         [0069]    The plug pin  20  has a hemispherical end part  22  of the pin-shaped plug part  21 , and the rear end has an electric line connection part  26 . 
         [0070]    An electric line  1  and core wire  2  are connected in a crimped fashion to the respective electric line connection parts  19  and  26 . 
         [0071]    A cut is made in the socket terminal  10  from the cylinder part  12  in which the side wall of the engagement part of the socket  11  is formed, and a bent tongue-shaped lance  17  is provided to broaden the end part on the outer side in the direction of the side of the electric line connection part, while a stabilizer  18  is erected toward the outside from the cylinder part  12 . 
         [0072]    The plug pin  20  is equipped with a lance  24  that is cut from a plug side surface part  23  and is set at an angle in order to expand the rear end on the outer side, while a stabilizer  25  is erected toward the outside from the plug side surface part  23 . 
         [0073]      FIG. 3  shows a socket connector in which the socket terminal  10  is installed onto the socket housing  30  and held with a lance clip, along with a plug connector  60  in which a plug pin  20  is installed onto the plug housing  40  and held with a lance clip. 
         [0074]    Sectional views in the horizontal direction of the respective housings are drawn, with  FIG. 3(   a ) showing the housings prior to engagement and  FIG. 3(   b ) showing them in an engaged state. 
         [0075]    A socket housing  30  is in the form of a cylinder that has been fabricated with an insulating resin, and it is equipped with a cylindrical receiver part  31  on the front side in the engagement direction, a cylindrical insertion part  32  on the rear side, and a terminal storage chamber  33  in the center of the cylinder. Along an inner wall  34  of the terminal storage chamber are a guide groove  35  and lance clip part  36 . 
         [0076]    Within the terminal storage chamber  33 , the socket terminal  10  is inserted along the stabilizer  18  in the guide groove  35  from the side of the cylindrical insertion part  32 , and once it is in position the lance  17  snaps into place on the lance clip part  36 . 
         [0077]    As is shown in  FIG. 3(   b ), the cylindrical receiver part  31  of the socket housing  30  is equipped with a cylindrical concave part  37  into which a cylindrical plug-in part  41  of the plug housing  40  is inserted and engaged. 
         [0078]    The plug housing  40  is cylindrical and has the cylindrical plug-in part  41  on the front side in the engagement direction as well as a cylindrical insertion part  42  on the rear side. The center of the cylinder is equipped with a terminal storage chamber  43 , and along an inner wall  44  of the terminal storage chamber are a guide groove  45  and lance clip part  46 . 
         [0079]    Within the terminal storage chamber  43 , the plug pin  20  is inserted along the stabilizer  25  in the guide groove  45  from the side of the cylindrical insertion part  42 , and once it is in position the lance  24  snaps into place on the lance clip part  46 . 
         [0080]    In this manner, the socket terminal  10  has the same installation configuration as the general configuration of the plug pin  20  and is installed within the socket housing  30 . 
         [0081]    As shown in  FIG. 3(   b ), a socket connector  50  and plug connector  60  are designed such that the cylindrical plug-in part  41  of the plug housing  40  is inserted into the cylindrical concave part  37  of the socket housing  30  to form an engagement in which the socket terminal  10  makes an electrical connection with the plug pin  20 . 
         [0082]    As shown in  FIG. 1 , in the socket part  11  of the socket terminal, a contact protrusion  14  that protrudes toward the inside from the cylinder part  12  via the front end part in the engagement direction is formed, along with an elastic contact arm  16  that extends inward from the cylinder part  12  in the vicinity of the center space part in the engagement direction. 
         [0083]    The elastic contact arm  16  is fabricated by forming a U-shaped notch part  16   d  in the cylinder part  12 . 
         [0084]    The contact protrusion  14  is formed through an embossing process of the cylinder part  12  from the outer side toward the inside. 
         [0085]    The elastic contact arm  16  is bent inward from the cylinder part  12  and has a flexible arm  16   a  with an elastic force toward the connection surface with the plug when contact is made with the plug pin, along with a slanted arm  16   b  that bends back toward the outside from the front end of the flexible arm  16   a.  The apex point in the bent back area of the slanted arm  16   b  and flexible arm  16   a  forms the contact point  16   c.    
         [0086]      FIG. 4  is an expanded explanatory diagram that illustrates the condition at the point where the plug part  21  is inserted into the socket part  11 . 
         [0087]    With the insertion of the plug part  21 , the plug front end part  22  strikes against the contact protrusion  14  as shown in  FIG. 4(   a ). 
         [0088]    Then, when the plug part  21  is inserted as is, the contact protrusion  14  is guided by the hemispherical tilting of the plug front end part  22 , such that it is lifted over the plug side surface part  23  and makes an electrical connection as shown in  FIG. 4(   b ). 
         [0089]    At this point, since the socket part  11  has a slit part  15  that has been formed along the insertion direction as shown in  FIG. 2(   b ), this slit part  15  widens to expand in diameter, and the plug part  21  can be inserted into the socket part  11  without collapsing the contact protrusion  14 . 
         [0090]    Further, when the plug part  21  is inserted, the plug front end part  22  slides into contact with the slanted arm  16   b  of the elastic contact arm  16 , and the flexible arm  16   a  bends toward the outer side while it is lifted to the plug side surface part  23 . 
         [0091]    Accordingly, an electrical connection is made when the contact point  16   c  is elastically connected to the plug side surface part  23  through the elastic restoration force of the flexible arm  16   a  as shown in  FIG. 4(   c ). 
         [0092]    It is acceptable for the elastic contact arm  16  to make an electrical connection through elastic contact while the flexible arm is allowed to bend in the plug part  21  that has been inserted into the socket part  11  in the fashion described above. Further, it is acceptable for the direction of the cut to be contrary to that described in this embodiment, that is, toward the rear. 
         [0093]      FIG. 5  shows an embodiment of a plug pin  70  in which the plug part  71  is equipped with an elastic contact arm  72  and contact protrusion  73 , and it is acceptable to make an electrical connection between the elastic contact arm  72  and the contact protrusion  73  on the inside surface of the socket terminal through engagement of the plug part  71  in the socket terminal. 
         [0094]    It is within the scope of the present invention to include all foreseeable equivalents to the elements of the present invention as described with relevance to  FIGS. 1(   a )- 5 . The examples provided by the disclosure are not to be interpreted as limiting the invention beyond that which is claimed.