Abstract:
A connection terminal includes a movable contact portion protruding out of a contact hole of a housing of the connection terminal, and is adapted to be pressed; a first curved portion continuously formed, the first curved portion including a free end portion having a fixed portion; a second curved portion continuously formed, the second curved portion including a free end portion having the movable contact portion; a rigid coupling portion interposed between the first curved portion and the second curved portion, and an abutment portion disposed on an opposite side to the second curved portion with respect to the movable contact portion, and adapted to be displaced toward the rigid coupling portion

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims benefit of priority to Japanese Patent Application No. 2012-174220, filed on Aug. 6, 2012 of which the full contents are herein incorporated by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to a connection terminal. 
         [0003]    In accordance with a conventional connection terminal as disclosed in Japanese Unexamined Patent Publication No. 9-35797, consists of a tamper-resistant contact wherein a contact composed of a conductor including a contact portion protruding into a bridge shape from a casing made of an insulating material, a cap member closing a space between the casing and the contact portion is provided on the contact. 
         [0004]    As illustrated in FIG. 3 of Japanese Unexamined Patent Publication No. 9-35797, the contact disclosed therein is formed by bending one long conductive plate. Therefore, this makes it difficult to adjust displacement amount of a contact portion in the connector which includes plural curved portions. Further, due to this configuration a contact position is hard to be controlled. As a result, there is a problem that the contact portion 3 collide with a base 4 to easily generate a plastic deformation. 
       SUMMARY OF THE INVENTION 
       [0005]    Accordingly, the invention provides a contact terminal which overcomes the above-mentioned problems and limitations of conventional art. Further, the invention provides a connection terminal in which the displacement amount of a movable contact portion is easily designed, particularly a connection terminal in which the plastic deformation caused by a collision of the movable contact portion due to an overload can be prevented, and a connector provided with the connection terminal. 
         [0006]    In accordance with one aspect of the present invention, there is provided a connection terminal comprising: a movable contact portion protruding out of a contact hole a housing of the connection terminal, and adapted to be pressed; a first curved portion continuously formed, the first curved portion comprising a free end portion having a fixed portion; a second curved portion continuously formed, the second curved portion comprising a free end portion having the movable contact portion; a rigid coupling portion interposed between the first curved portion and the second curved portion; and an abutment portion disposed on an opposite side to the second curved portion with respect to the movable contact portion, and adapted to be displaced toward the rigid coupling portion. 
         [0007]    Preferably, the rigid coupling portion is a coupling portion that has rigidity larger than those of the first curved portion and the second curved portion. Further, the rigid coupling portion can be realized by increasing a spring constant of a coupling portion between the first curved portion and the second curved portion as compared with spring constants of the first curved portion and the second curved portion. 
         [0008]    In accordance with one of the preferred embodiments of the present invention, the first curved portion and the second curved portion may be formed by a plurality of curved extending portions, and a curved slit may be provided between the curved extending portions. 
         [0009]    In accordance with another embodiment of the present invention, the abutment portion is adapted to abut on the rigid coupling portion. 
         [0010]    In accordance with still another embodiment of the present invention, an abutting protrusion that protrudes from an outward surface of the rigid coupling portion and is adapted to abut on the abutment portion. 
         [0011]    In accordance with another aspect of the present invention, there is provided a connector has a configuration in which the movable contact portion of the connection terminal protrudes out of a contact hole of a housing of the connection terminal and is adapted to be pressed. 
         [0012]    In accordance with yet another embodiment of the present invention, the housing comprises an inner peripheral edge portion and the edge portion having a positioning portion, such that the abutment portion abuts on the positioning portion. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The invention will become more readily appreciated and understood from the following detailed description of preferred embodiments of the invention when taken in conjunction with the accompanying drawings, in which: 
           [0014]      FIG. 1A  is a perspective view illustrating a connector in which a connection terminal according to the first embodiment of the present invention is incorporated; 
           [0015]      FIG. 1B  is a right side view illustrating a connector in which a connection terminal according to the first embodiment of the present invention is incorporated; 
           [0016]      FIG. 1C  is a partial sectional view illustrating a connector in which a connection terminal according to the first embodiment of the present invention is incorporated; 
           [0017]      FIG. 2A  is a plan view illustrating the connector, as shown in  FIGS. 1A ,  1 B and  1 C, in which the connection terminal of the first embodiment is incorporated; 
           [0018]      FIG. 2B  is a front view illustrating the connector, as shown in  FIGS. 1A ,  1 B and  1 C, in which the connection terminal of the first embodiment is incorporated; 
           [0019]      FIG. 3A  is a rear view illustrating the connector, as shown in  FIGS. 1A ,  1 B and  1 C, in which the connection terminal of the first embodiment is incorporated; 
           [0020]      FIG. 3B  is a bottom view illustrating the connector, as shown in  FIGS. 1A ,  1 B and  1 C, in which the connection terminal of the first embodiment is incorporated; 
           [0021]      FIG. 4A  is a sectional view illustrating the connector, as shown in  FIGS. 1A ,  1 B and  1 C, in which the connection terminal of the first embodiment is incorporated before an operation; 
           [0022]      FIG. 4B  is a sectional view illustrating the connector , as shown in  FIGS. 1A ,  1 B and  1 C, in which the connection terminal of the first embodiment is incorporated during an operation; 
           [0023]      FIG. 4C  is a sectional view illustrating the connector , as shown in  FIGS. 1A ,  1 B and  1 C, in which the connection terminal of the first embodiment is incorporated after an operation; 
           [0024]      FIG. 5A  is a perspective view of housing alone as shown in  FIGS. 1A ,  1 B and  1 C; 
           [0025]      FIG. 5B  is a partial sectional view of housing alone as shown in  FIGS. 1A ,  1 B and  1 C; 
           [0026]      FIG. 5C  is a central sectional view of housing alone as shown in  FIGS. 1A ,  1 B and  1 C; 
           [0027]      FIG. 6A  is a perspective view illustrating the connection terminal of the first embodiment; 
           [0028]      FIG. 6B  is a front view illustrating the connection terminal of the first embodiment; 
           [0029]      FIG. 7A  is front view illustrating connection terminal in accordance with a second embodiment of the present invention; 
           [0030]      FIG. 7B  is front view illustrating connection terminal in accordance with a third embodiment of the present invention; 
           [0031]      FIG. 8A  is front view illustrating connection terminal in accordance with a fourth embodiment of the present invention; 
           [0032]      FIG. 8B  is front view illustrating connection terminal in accordance with a fifth embodiment of the present invention; 
           [0033]      FIG. 9A  is a perspective view illustrating a connection terminal in accordance with a sixth embodiment of the present invention; 
           [0034]      FIG. 9B  is a front view illustrating a connection terminal in accordance with the sixth embodiment of the present invention; 
       
    
    
     DETAILED DESCRIPTION 
       [0035]    The present invention is described hereinafter by various embodiments with reference to the accompanying drawings, wherein reference numerals used in the accompanying drawings correspond to the like elements throughout the description. Further, while discussing various embodiments, cross reference will made between the figures. In order to achieve full description and explanation, specific details have been mentioned to provide thorough and comprehensive understanding of various embodiments of the present invention. However, said embodiments may be utilized without such specific details and in various other ways broadly covered herein. 
         [0036]    A connection terminal according to an exemplary embodiment of the present invention will be described below with reference to  FIGS. 1 to 9 . 
         [0037]    As illustrated in  FIGS. 1 to 6 , a connector in accordance with the first embodiment of the present invention comprises of fixing metal fittings  20  which are press-fitted in both ends of a resin-molded housing  10 , and connection terminals  30  which are press-fitted, at predetermined intervals, between the fixing metal fittings  20 . Preferably, the housing  10  of the connector has outside dimensions of a height of 3.5 mm and a maximum depth of 2.8 mm, and the housing  10  is assembled in a printed board (not illustrated) by fitting the housing  10  in a substantial U-shape notch provided in an upper-surface edge portion of the printed board. 
         [0038]    As illustrated in  FIGS. 5A ,  5 B and  5 C, bulging-out portions  11  protrude laterally in the housing  10 , and the bulging-out portions  11  are continuously provided along side surfaces and a rear surface of the housing  10 . A first storage space  12  in which the fixing metal fitting  20  (to be described) can be press-fitted in from above is provided at each end of the bulging-out portion  11  ( FIG. 5B ). A press-fitting latch hole  13  is made along inside surfaces opposed to each other in the first storage space  12 . A positioning protrusion  14  protrudes from a bottom base in the bulging-out portion  11 . 
         [0039]    In the housing  10 , three of second storage spaces  15  are provided, in parallel, between the first storage spaces  12 . Further, in each of the second storage spaces  15  the connection terminal  30  can be press-fitted from above. Particularly, the second storage space  15  provided in a position adjacent to the first storage space  12  which is partitioned by a partition wall  15   a.  As shown in  FIG. 5C , in the housing  10 , a contact hole  16  is made on a front surface side thereof and a lower inner peripheral edge portion of the contact hole  16  is used as a positioning portion  16   a.  Further, the contact hole  16  is communicated with the second storage space  15 , and a movable contact portion  38  of the connection terminal  30  (to be described) can be inserted in and taken out from the contact hole  16 . Also, a press-fitting latch hole  17  is made in the housing  10  and communicates with the second storage space  15 . 
         [0040]    As illustrated in  FIG. 1C , the fixing metal fitting  20  is a press-formed product that is formed by punching a metallic thin plate. Further, a latching pawl  21  and a positioning support  22  are provided in parallel within the fixing metal fitting  20 . Therefore, the latching pawl  21  of the fixing metal fitting  20  is press-fitted from above in the press-fitting latch hole  13  of the first storage space  12  which is provided in the housing  10 , whereby the fixing metal fitting  20  is retained and the positioning support  22  of the fixing metal fitting  20  is flush with a lower end face of the positioning protrusion  14  of the housing  10 . 
         [0041]    As illustrated in  FIGS. 6A and 6B , in the connection terminal  30 , a press-fitting latching pawl  32   a  protrudes downward from an intermediate position of a fixed portion  31 , a support  33  extends downward from one end of the fixed portion  31 , and a substantial L-shape terminal portion  32   b  extends downward from the other end of the fixed portion  31 . A substantial U-shape first curved portion  35  extends from a branch portion  34  located at a leading end of the support  33 , and a substantial U-shape second curved portion  37  in which an opening is disposed in the opposite direction to the first curved portion  35  extends from the first curved portion  35  where an abutment-receiving portion  36  of the rigid coupling portion is interposed therebetween. The first curved portion  35  and the second curved portion  37  are disposed into a substantial S-shape while continuously coupled to each other with the abutment-receiving portion  36  interposed therebetween. More specifically, openings of the curved portion  35  and the second curved portion  37  are oriented toward the opposite directions to each other with respect to a line segment connecting ends of the first curved portion  35  and the second curved portion  37 . Therefore, advantageously a stress is hardly concentrated on the support  33 , a life is lengthened, and a degree of design freedom increases. Further, the first curved portion and the second curved portion are continuously provided with the rigid coupling portion interposed therebetween, so that an elastic deformation amount can be designed in each of the first curved portion and the second curved portion. Therefore, the displacement amount of the movable contact portion is easily and accurately designed to obtain the connection terminal that can prevent the plastic deformation caused by an external load. 
         [0042]    Preferably, the rigid coupling portion  36  is not necessarily an ideal rigid body, but the rigid coupling portion  36  only need to play a role considerable as a rigid body, without being deformed when the first curved portion  35  and the second curved portion  37  are elastically deformed. 
         [0043]    In the first curved portion  35 , a first extending portion  40   a  and a second extending portion  40   b  extend from the branch portion  34  so as to meander substantially in parallel with each other, and a curved slit  41  is formed between the first extending portion  40   a  and the second extending portion  40   b.    
         [0044]    In the second curved portion  37 , a first extending portion  42   a  and a second extending portion  42   b  extend from the abutment-receiving portion  36  so as to meander substantially in parallel with each other, and a curved slit  43  is formed between the first extending portion  42   a  and the second extending portion  42   b.    
         [0045]    In the second curved portion  37 , a portion located in an outside surface of a free end portion is used as a thick movable contact portion  38 , and an abutment portion  39  extends to an inside from an inside surface of the free end portion. The abutment portion  39  can abut on the abutment-receiving portion  36  of the rigid coupling portion. Accordingly due this configuration, even if an overload is applied to the movable contact portion, the movable contact portion abuts on the rigid coupling portion to prevent the plastic deformation, and the connection terminal that can withstand the large load may be obtained. 
         [0046]    In the present embodiment, each of the first and second extending portions  40   a,    40   b,    42   a,  and  42   b  does not have an equal width, but the width of the curved portion located on the outside is made larger than the width of the curved portion located on the inside. For this reason, advantageously the stress concentration is further hardly generated during an operation, and a life is lengthened. Further, the width of the slits  41  and  43  of the present embodiment are not necessarily equal, but the widths may of course vary as needed basis. 
         [0047]    As illustrated in  FIGS. 4A ,  4 B and  4 B, the connection terminal  30  is inserted from above in the second storage space  15  of the housing  10 . The press-fitting latching pawl  32   a  of the fixed portion  31  is press-fitted in and latched in the press-fitting latch hole  17 . Therefore, the abutment portion  39  of the second curved portion  37  abuts on a positioning portion  16   a  provided in the lower inner peripheral edge portion of the contact hole  16  in the housing  10  to establish the positioning ( FIG. 4A ). 
         [0048]    The fixing metal fitting  20  is inserted in the first storage space  12  of the housing  10 , and the latching pawl  21  of the fixing metal fitting  20  is press-fitted in and fixed to the press-fitting hole  13  of the housing  10  ( FIG. 1C ). 
         [0049]    The method for fixing the housing  10  to the connection terminal  30  or the fixing metal fitting  20  is not limited to the press fitting, but other methods for fixing such as adhesion and nipping may be adopted. 
         [0050]    According to above configuration, advantageously the movable contact portion is accurately positioned, and the connector in which variation in an operating characteristic is small can be obtained. 
         [0051]    According to the present embodiment, as illustrated in  FIGS. 1C and 5A , the lower end face of the positioning protrusion  14  provided in the bottom surface of the bulging-out portion  11  is flush with the lower end face of the positioning support  22  of the fixing metal fitting  20  and the lower end face of the terminal portion  32   b  of the connection terminal  30 . Therefore, when the connector of the present embodiment is assembled in the substantial U-shape notch provided in the edge portion of the printed board (not illustrated) to insert the latching pawl  21  of the fixing metal fitting  20  in a positioning through-hole made in the printed board, advantageously the connector can be assembled in the printed board with no rattle. 
         [0052]    As illustrated in  FIG. 4B , when an external force is applied to the movable contact portion  38  of the connection terminal  30 , at first the second curved portion  37  is curved inward, the abutment portion  39  moves inward toward the abutment-receiving portion  36 , and the second curved portion  37  is elastically deformed inward. When the movable contact portion  38  is further pushed, as illustrated in  FIG. 4C , the abutment portion  39  abuts on the abutment-receiving portion  36  to regulate the elastic deformation of the second curved portion  37  wherein the rigidity is larger than that of the first curved portion  35  and the second curved portion  37 , and hence the first curved portion  35  is largely elastically deformed. Due to this configuration, the stress concentration on the second curved portion  37  can be relaxed to effectively prevent the generation of the plastic deformation. 
         [0053]    When the load on the movable contact portion  38  is removed, the connection terminal  30  can be returned to an initial position in  FIG. 4A . That is, the shape of the abutment portion  39  is defined such that the abutment portion  39  abuts on the abutment-receiving portion  36  within a range in which the connection terminal  30  can elastically be deformed. 
         [0054]    In the present embodiment, the description has been made on the configuration, in which the abutment portion  39  abuts on the abutment-receiving portion  36  of the rigid coupling portion. However, the abutting position of abutment portion  39  may be anywhere in a region where the first curved portion  35  and the second curved portion  37  are continuously coupled. 
         [0055]    According to the present embodiment, the first curved portion  35  and second curved portion  37  are provided between the movable contact portion  38  and the fixed portion  31  while the abutment-receiving portion  36  is interposed between the first curved portion  35  and second curved portion  37 , and a spring length is long. Therefore, the stress concentration is hardly generated while the desired displacement amount is ensured. For this reason, the long-life connector may be obtained wherein plastic deformation is hardly generated. 
         [0056]    As illustrated in  FIG. 7A , a connector according to a second embodiment is substantially identical to the connector of the first embodiment. Further, the connector of the second embodiment differs from the connector of the first embodiment in that a substantial L-shape abutting protrusion  36   a  that can abut on the abutment portion  39  protrudes from the inside surface of the abutment-receiving portion  36 . Because other configurations are identical to those of the first embodiment, the identical component is designated by the identical numeral, and the description thereof is omitted. 
         [0057]    According to the present embodiment, because the substantial L-shape abutting protrusion  36   a  protrudes from the abutment-receiving portion  36 , advantageously the abutting protrusion  36   a  can absorb and relax an impact force of the abutment portion  39  to prevent the plastic deformation of the connection terminal  30 . 
         [0058]    As illustrated in  FIG. 7B , a connector according to a third embodiment is substantially identical to the connector of the first embodiment. Further, the connector of the third embodiment differs from the connector of the first embodiment in that the first extending portion  40   a,  the second extending portion  40   b,  and a third extending portion  40   c  extend from the branch portion  34  so as to substantially meander in parallel with one another, thereby forming curved slits  41   a  and  41   b . The abutment portion  39  can abut on the abutment-receiving portion  36  of the rigid coupling portion. Because other configurations are identical to those of the first embodiment, the identical component is designated by the identical numeral, and the description thereof is omitted. 
         [0059]    According to the present embodiment, the first curved portion  35  is constructed by the first, second, and third extending portions  40   a,    40   b,  and  40   c . Therefore, advantageously the second curved portion  37  can be supported with a larger support force, and the plastic deformation of the second curved portion  37  can be prevented. 
         [0060]    As illustrated in  FIG. 8A , a connector according to a fourth embodiment is substantially identical to the connector of the first embodiment. Further the connector of the fourth embodiment differs from the connector of the first embodiment in that the first curved portion  35  is constructed by the one extending portion  40   a.  Because other configurations are identical to those of the first embodiment, the identical component is designated by the identical numeral, and the description thereof is omitted. 
         [0061]    According to the present embodiment, advantageously the shape of the first curved portion  35  is simplified and a metallic mold can be produced easily. 
         [0062]    As illustrated in  FIG. 8B , a connector according to a fifth embodiment is substantially identical to the connector of the first embodiment. Further the connector of the fifth embodiment differs from the connector of the first embodiment in that the second curved portion  37  is constructed by the one extending portion  42   a.  Because other configurations are identical to those of the first embodiment, the identical component is designated by the identical numeral, and the description thereof is omitted. 
         [0063]    According to the present embodiment, advantageously the shape of the second curved portion  37  is simplified and a metallic mold can be produced easily. 
         [0064]    In a connector according to a sixth embodiment, as illustrated in  FIGS. 9A and 9B , a substantial-L-shape terminal portion  32   b  that can be press-fitted in the housing extends onto one side from the fixed portion  31 . The first curved portion  35  extends from the fixed portion  31  while the support  33  provided on the other side is interposed between the first curved portion  35  and the fixed portion  31 , and the second curved portion  37  extends from the first curved portion  35  with the abutment-receiving portion  36  interposed therebetween. Therefore, advantageously the stress is hardly concentrated on the fixed portion  31 , the life is lengthened, and the degree of design freedom increases. 
         [0065]    The first curved portion  35  is constructed by the first extending portion  40   a  extending from the support portion  33 , and the second curved portion  37  is constructed by the first extending portion  42   a  extending from the abutment-receiving portion  36 . In the second curved portion  37 , a portion located in the outside surface of the free end portion is used as the movable contact portion  38 , and a leading end extends inward to form the abutment portion  39 . The abutment portion  39  can abut on the abutment-receiving portion  36 . Particularly, the abutment-receiving portion  36  is widened and subjected to bending work, thereby enhancing the rigidity. Because other configurations are identical to those of the first embodiment, the identical component is designated by the identical numeral, and the description thereof is omitted. 
         [0066]    According to the present embodiment, advantageously the connector can be produced by the press working to widen selection of the production method. 
         [0067]    In the above embodiments, the description has been made on the case where the set of two connection terminals and the one connection terminal are combined in order to enhance connection reliability. Alternatively, the connector may be composed of only the one connection terminal, or only the set of two connection terminals. A set of three connection terminals may be incorporated, and the number of connection terminals can of course be selected as needed basis. The extending portion and the slit do not necessarily have the equal width, but the width may be changed as needed basis. For example, in the curved portion of the extending portion, only the width of the curved portion of the extending portion located on the outside is increased, and the generation of the stress concentration may be prevented to enhance durability. 
         [0068]    In the embodiments, the description has been made on the case where the connection terminal is incorporated in the housing. Alternatively, the printed board itself may be used as the housing, and the connection terminal of the present application may directly be incorporated in the side end face thereof. Therefore, advantageously the conventional housing and fixing metal fitting are no longer needed, and consequently a whole device can further be downsized. 
         [0069]    The connector in which the connection terminal of the present invention is incorporated is not limited to the shapes described above, but the connector may of course be formed into a shape that can be surface-mounted on an upper surface of the printed board. 
         [0070]    There has thus been shown and described a connecting terminal and a connector which fulfills all the objects and advantages sought therefore. Many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art after considering this specification and the accompanying drawings which disclose the preferred embodiments thereof. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is to be limited only by the claims which follow. 
         [0071]    Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present invention contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment.