Patent Publication Number: US-9425530-B2

Title: Contact having a spring portion joined to a second spring portion having a convex shaped bent fulcrum portion

Description:
This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2014-223237, filed on Oct. 31, 2014, the disclosure of which is incorporated herein in its entirety by reference. 
     BACKGROUND OF THE INVENTION: 
     This invention relates to a contact and a connector comprising the contact. 
     As an elastic contact for use in a ground/signal/antenna connection connector or a card connector for a digital device such as a smartphone, there is known a structure as described in JP-A-2014-35835 (Patent Document 1) in which, in order to achieve miniaturization of a contact while maximizing its spring length, two types of plate springs are placed side by side and joined together and an end portion of only one of the plate springs is fixed to a board of a digital device. 
     In such a structure, however, in order to design the properties as a spring such as a contact force and a displacement amount when a connection object is in contact with the contact, the balance of forces of the two types of plate springs should be strictly designed as described in, for example, JP-A-2014-75332 (Patent Document 2). 
     This point will be described with reference to  FIG. 12 . As shown in  FIG. 12 , a contact  30  of Patent Document 2 comprises a fixing portion  31  fixed to a connector body  10 , a first spring portion  33  provided in a rectangular annular shape and elastically deformable relative to the fixing portion  31 , a second spring portion  34  projectingly provided on the inner peripheral side of the first spring portion  33  and elastically deformable relative to the first spring portion  33 , and a contact portion  35  provided at a free end of the second spring portion  34 . 
     With this structure, when a connection object such as a card is pressed against the contact portion  35 , the contact portion  35  is pushed down toward the board  3  side, while an opposite side portion  33 A or a joining portion  37  rises, so that the first spring portion  33  and the second spring portion  34  are elastically deformed. 
     Herein, in order to balance the forces of the first spring portion  33  and the second spring portion  34  as the two types of plate springs, the contact  30  is designed so that the spring stiffness of the first spring portion  33  and the spring stiffness of the second spring portion  34  are equal to each other. Specifically, a value twice the width of each of lateral side portions  33 B of the first spring portion  33  and a value of the width of the second spring portion  34  are approximate to each other. 
     SUMMARY OF THE INVENTION: 
     However, as described above, in the structure of Patent Document 2, the size of each of the first spring portion  33  and the second spring portion  34  is regulated by the size of the other. Therefore, there is a problem that it is difficult to design the first spring portion  33  and the second spring portion  34  independently of each other, resulting in that the degree of freedom of design is low. 
     This invention has been made in order to solve the above-mentioned problem and has an object to provide a contact that enables its properties as a spring to be designed more easily than before. 
     In order to achieve the above-mentioned object, a first aspect of this invention is a contact electrically connecting a plurality of connection objects, comprising: a to-be-fixed portion adapted to be fixed to a fixing member; a first spring portion comprising a rearward end portion, in a front-rear direction, joined to the to-be-fixed portion, the first spring portion extending forward from the to-be-fixed portion and elastically deformable relative to the to-be-fixed portion; a joining portion joined to a forward end portion of the first spring portion; a second spring portion comprising a forward end portion joined to the joining portion, the second spring portion disposed adjacent to the first spring portion in a width direction perpendicular to the front-rear direction, extending rearward from the joining portion, and elastically deformable relative to the joining portion; and a contact portion provided to the second spring portion and adapted to be in contact with a terminal of one of the connection objects, wherein the second spring portion comprises, between the forward end portion thereof and a rearward end portion thereof, a fulcrum bend portion that is convex in a downward direction perpendicular to the front-rear direction and to the width direction and that is adapted to be constantly in contact with the fixing member, and wherein the fulcrum bend portion is disposed between the forward end portion of the first spring portion and the contact portion in the front-rear direction, and the contact portion is disposed between the fulcrum bend portion and the rearward end portion of the first spring portion in the front-rear direction. 
     In the contact, two to-be-fixed portions and two first spring portions may be provided in the width direction, and the second spring portion may be disposed between the two first spring portions in the width direction. 
     The first spring portion may be provided with a first bend portion, the first spring portion may be provided with a second bend portion between the first bend portion and the rearward end portion, and the first spring portion may comprise, between the first bend portion and the second bend portion, a portion which is convex in an upward direction perpendicular to the front-rear direction and to the width direction. 
     In this structure, the first spring portion may comprise a third bend portion provided between the contact portion and the second bend portion in the front-rear direction. 
     Further, if two to-be-fixed portions and two first spring portions are provided, the two to-be-fixed portions may be joined together. 
     Still further, in a structure which comprises the third bend portion, the first spring portion may comprise a fourth bend portion provided between the first bend portion and the third bend portion. 
     On the other hand, the contact is formed from a single plate-shape member for example. 
     The fixing member is the other of the connection objects for example, and, the to-be-fixed portion is adapted to be fixed to the other of the connection objects by soldering. In this case, the other of the connection objects is a board for example. 
     Further, the fixing member may be a connector body which forms a connector adapted to be attached to the other of the connection objects. 
     A second aspect of this invention is a connector comprising a connector body and the contact according to the first aspect fixed to the connector body 
     EFFECT OF THE INVENTION 
     According to this invention, it is possible to provide a contact that enables its properties as a spring to be designed more easily than before. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS: 
         FIG. 1  is a perspective view showing a contact  1  according to a first embodiment of this invention; 
         FIG. 2  is a side view showing a connector  101  comprising the contact  1 ; 
         FIG. 3  is a side view for explaining the sequence of attaching a mating board  53  as a connection object to the connector  101  comprising the contact  1 ; 
         FIG. 4  is a side view showing a state where the mating board  53  as the connection object is attached to the connector  101  comprising the contact  1 ; 
         FIG. 5  is a perspective view showing a contact  81  according to a second embodiment of this invention; 
         FIG. 6  is a perspective view showing a contact  83  according to a third embodiment of this invention; 
         FIG. 7  is a side view showing a connector  103  comprising the contact  83 ; 
         FIG. 8  is a side view showing a state where a mating board  53  as a connection object is attached to the connector  103  comprising the contact  83 ; 
         FIG. 9  is a perspective view showing a contact  85  according to a fourth embodiment of this invention; 
         FIG. 10  is a perspective view showing a contact  87  according to a fifth embodiment of this invention; 
         FIG. 11  is a side view showing a connector  105  comprising a contact  89  according to a sixth embodiment of this invention, wherein a connector body  56  is shown in cross section; and 
         FIG. 12  is a perspective view showing a conventional contact  30 . 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION: 
     Hereinbelow, preferred embodiments of this invention will be described in detail with reference to the drawings. 
     First, referring to  FIGS. 1 and 2 , the structure of a contact  1  according to a first embodiment of this invention will be described. 
     In the following description, it is assumed that a direction A in  FIG. 1  is forward and that a direction B in  FIG. 1  is rearward. 
     As shown in  FIGS. 1 and 2 , the contact  1  comprises a to-be-fixed portion  4  adapted to be fixed to a connector board  51  ( FIG. 2 ) as a fixing member, a first spring portion  7  joined to the to-be-fixed portion  4  and extending forward (direction A) from the to-be-fixed portion  4  so as to be elastically deformable relative to the to-be-fixed portion  4  or relative to the connector board  51  when the to-be-fixed portion  4  is fixed thereto, and a joining portion  11  joined to the first spring portion  7 . 
     The contact  1  further comprises a second spring portion  17  joined to the joining portion  11 , disposed adjacent to the first spring portion  7 , and extending rearward (direction B) from the joining portion  11  so as to be elastically deformable relative to the joining portion  11 , and a contact portion  13  provided to the second spring portion  17  and adapted to be in contact with a terminal  55  of a mating board  53  ( FIG. 2 ) as one of connection objects. 
     Next, the respective members forming the contact  1  will be described in further detail with reference to  FIGS. 1 and 2 . 
     The to-be-fixed portion  4  is a terminal adapted to be fixed to the connector board  51  by soldering or the like. 
     The first spring portion  7  is a plate spring extending in the direction A from the to-be-fixed portion  4  and comprises a plate-shape first spring body  8 , a first front end portion  9  as a forward end portion of the first spring body  8 , and a first rear end portion  5  as a rearward end portion of the first spring body  8 . The first rear end portion  5  is joined to the to-be-fixed portion  4  and the first front end portion  9  is joined to the joining portion  11 . 
     The joining portion  11  is a plate-shape member joining the first spring portion  7  and the second spring portion  17  together. 
     The second spring portion  17  is disposed adjacent to the first spring portion  7  in the width direction (direction C) perpendicular to the front-rear direction and comprises a plate-shape base portion  19  joined to the joining portion  11  and extending in the direction B from the joining portion  11 , a plate-shape inclined portion  21  inclined upward in  FIG. 1  (in a direction perpendicular to the directions A and B and to the directions C and D, i.e. in a direction F) with respect to the base portion  19 , the curved plate-shape contact portion  13  provided to the inclined portion  21 , and a fulcrum bend portion  23  joining the base portion  19  and the inclined portion  21  together. 
     The second spring portion  17  comprises a second front end portion  25  as its forward end portion and a second rear end portion  27  as its rearward end portion. The second front end portion  25  is provided to the base portion  19  and joined to the joining portion  11  and the second rear end portion  27  is joined to the contact portion  13 . The fulcrum bend portion  23  is provided between the second front end portion  25  and the second rear end portion  27 . That is, the fulcrum bend portion  23  is provided rearward of the joining portion  11  in the front-rear direction. 
     The fulcrum bend portion  23  is convex downward in  FIG. 1  (in a direction perpendicular to the directions A and B and to the directions C and D, i.e. in a direction E) and is constantly in contact with the connector board  51  when the contact  1  is mounted on the connector board  51  (see  FIG. 2 ). 
     The contact portion  13  is disposed between the fulcrum bend portion  23  and the first rear end portion  5  of the first spring portion  7  in the front-rear direction. 
     The contact  1  is formed from a single plate-shape member such as a conductive metal plate. 
     The above is a description of the structure of the contact  1 . 
     Next, the structure of a connector  101  comprising the contact  1  will be described with reference to  FIG. 2 . 
     As shown in  FIG. 2 , the connector  101  includes the connector board  51  as the other connection object, the contact  1  mounted on the connector board  51  such that the to-be-fixed portion  4  is fixed to the connector board  51 , and clips  54  in the form of elastic springs provided to the connector board  51 . Each clip  54  comprises a tapered portion  57  with its upper surface inclined toward the contact  1  side. 
     Although details will be described later, the connector  101  fixes the mating board  53  by sandwiching the mating board  53  between the clips  54  and the contact  1 . 
     The above is a description of the structure of the connector  101 . 
     Next, the sequence of attaching the mating board  53  to the connector  101  will be described with reference to  FIGS. 2 to 4 . 
     First, in the state shown in  FIG. 2 , the mating board  53  is disposed above the connector  101  so that the terminal  55  of the mating board  53  faces the contact portion  13  of the contact  1 . 
     Then, from this state, as shown in  FIG. 3 , the mating board  53  is moved downward (direction E) to abut against the tapered portions  57  of the clips  54  and is further pushed in the direction E to force open the clips  54 . 
     In this state, the mating board  53  also abuts against the contact portion  13  of the second spring portion  17  to push the contact portion  13  in the direction E. 
     Then, the second spring portion  17  is rotated in a direction G in  FIG. 3  centering around the fulcrum bend portion  23 . 
     Since the joining portion  11  is joined to the second spring portion  17 , the joining portion  11  is rotated in the direction G in  FIG. 3  and thus raised from the connector board  51 . 
     Further, since the first spring portion  7  is joined to the second spring portion  17  via the joining portion  11 , the first front end portion  9  of the first spring portion  7  is also raised from the connector board  51 . 
     When the mating board  53  pushes open the clips  54  until the mating board  53  is separated from the tapered portions  57 , the clips  54  are each returned to its initial shape by elasticity so that, as shown in  FIG. 4 , the clips  54  are in abutment with the mating board  53  to hold therebetween the mating board  53  jointly with the contact portion  13  of the second spring portion  17 . 
     In this state, the terminal  55  of the mating board  53  and the contact portion  13  of the second spring portion  17  are in electrical contact with each other, wherein the mating board  53  is attached to the connector  101 . 
     Herein, the fulcrum bend portion  23  is constantly in contact with the connector board  51  in all cases of  FIGS. 2 to 4  and serves as a fulcrum when the contact  1  is deformed so that the second spring portion  17  is rotated in the direction G. 
     Therefore, it is possible to design the first spring portion  7  and the second spring portion  17  independently of each other. 
     More specifically, in the state shown in  FIG. 4 , a force of the contact portion  13  to abut against the terminal  55  (force to push the terminal  55  in the direction F) depends on a force (direction E) of the first spring portion  7  to return to the connector board  51  side and a force (direction F) of the second spring portion  17  to return to the height before the displacement. 
     On the other hand, since the fulcrum bend portion  23  is constantly in contact with the connector board  51 , the force of the first spring portion  7  to return to the connector board  51  side and the force of the second spring portion  17  to return to the height before the displacement can be set individually. 
     As shown in  FIG. 4 , in the state where the mating board  53  is attached to the connector  101 , the joining portion  11  is in the state of being raised from the connector board  51 . In this event, if a distance H 1  between the joining portion  11  (herein, an upper surface of the joining portion  11 ) and the connector board  51  is greater than or equal to a distance H 2  between the contact portion  13  (herein, an upper surface of the contact portion  13 ) and the connector board  51 , the joining portion  11  is brought into abutment with the mating board  53  so that there is a possibility of the occurrence of wear of the contact  1  or the mating board  53  or a short circuit, and since the displacement of the first spring portion  7  is regulated, its displacement amount decreases so that there is a possibility that a predetermined contact force is not obtained between the terminal  55  of the mating board  53  and the contact portion  13  of the second spring portion  17 . Therefore, the distance H 1  is preferably less than the distance H 2 . 
     Herein, since the fulcrum bend portion  23  of the contact  1  is constantly in contact with the connector board  51 , there is an advantage in that the distance H 1  can be easily estimated compared to the case of non-contact therebetween (conventional structure). 
     Accordingly, also from this point, the spring properties of the contact  1  can be designed more easily than the conventional structure. 
     As described above, according to the first embodiment, the contact  1  comprises the to-be-fixed portion  4  adapted to be fixed to the connector board  51 , the first spring portion  7  joined to the to-be-fixed portion  4  and extending forward from the to-be-fixed portion  4  so as to be elastically deformable relative to the to-be-fixed portion  4  or relative to the connector board  51  when the to-be-fixed portion  4  is fixed thereto, the joining portion  11  joined to the first spring portion  7 , the second spring portion  17  joined to the joining portion  11 , disposed adjacent to the first spring portion  7 , and extending rearward from the joining portion  11  so as to be elastically deformable relative to the joining portion  11 , and the contact portion  13  provided to the second spring portion  17  and adapted to be in contact with the terminal  55  of the mating board  53  as one of the connection objects, wherein the fulcrum bend portion  23  adapted to be constantly in contact with the connector board  51  is provided between the second front end portion  25  and the second rear end portion  27  of the second spring portion  17 , the fulcrum bend portion  23  is disposed between the first front end portion  9  as the forward end portion of the first spring portion  7  and the contact portion  13  in the front-rear direction, and the contact portion  13  is disposed between the fulcrum bend portion  23  and the first rear end portion  5  as the rearward end portion of the first spring portion  7  in the front-rear direction. 
     With this structure, it is possible to design the first spring portion  7  and the second spring portion  17  independently of each other. 
     Next, a second embodiment of this invention will be described with reference to  FIG. 5 . 
     The second embodiment is configured such that two to-be-fixed portions  4  and two first spring portions  7  are provided in the first embodiment. 
     In the second embodiment, the same reference numerals as in the first embodiment are assigned to components that achieve the same functions as in the first embodiment and portions different from those of the first embodiment will be mainly described. 
     As shown in  FIG. 5 , a contact  81  according to the second embodiment comprises two to-be-fixed portions  4  and two first spring portions  7 . 
     Specifically, the two to-be-fixed portions  4  and the two first spring portions  7  are provided in a direction C in  FIG. 5  (i.e. in the width direction). 
     A second spring portion  17  is disposed between the two first spring portions  7 . 
     With this structure, compared to the case where the single first spring portion  7  is provided, the second spring portion  17  is difficult to deform in the direction C or D. 
     Therefore, even in the case where the deformation of the second spring portion  17  arises as an issue, it is possible to prevent the second spring portion  17  from bending in the direction C or D. 
     Accordingly, the contact  81  according to the second embodiment is suitable for a case where importance is attached to the stability. 
     Next, a third embodiment of this invention will be described with reference to  FIGS. 6 to 8 . 
     The third embodiment is configured such that each of the first spring portions  7  is provided with a first bend portion  61  and a second bend portion  63  in the second embodiment. 
     In the third embodiment, the same reference numerals as in the second embodiment are assigned to components that achieve the same functions as in the second embodiment and portions different from those of the second embodiment will be mainly described. 
     As shown in  FIGS. 6 to 8 , a contact  83  according to the third embodiment is configured such that a first spring body  8  of each of first spring portions  7  is provided with a first bend portion  61  and a second bend portion  63 . 
     More specifically, the first bend portion  61  is provided between a first front end portion  9  and a fulcrum bend portion  23  in the front-rear direction and the second bend portion  63  is provided between the first bend portion  61  and a first rear end portion  5 . 
     Since the first bend portion  61  and the second bend portion  63  are each bent so as to be convex downward, a third bend portion  65  which is convex upward (convex in a direction F) is provided between the first bend portion  61  and the second bend portion  63 . The third bend portion  65  is provided between the first rear end portion  5  and a contact portion  13  in the front-rear direction. 
     An advantage with this structure will be described with reference to  FIGS. 6 and 7 . 
     When handling the contact  83  shown in  FIG. 6  alone or when handling a connector board  51  after the contact  83  is mounted on the connector board  51  in the state where clips  54  shown in  FIG. 7  are not attached to the connector board  51 , if a mounting tool, a hand, or the like abuts against a second spring portion  17 , there is a possibility of damage to the second spring portion  17 . 
     In view of this, as shown in  FIG. 6 , by providing the third bend portions  65 , which are convex upward, between the first bend portions  61  and the second bend portions  63  (particularly between the first rear end portions  5  and the contact portion  13 ), even if the mounting tool, the hand, or the like approaches the contact portion  13  or the second spring portion  17  from the to-be-fixed portion  4  side, the mounting tool, the hand, or the like may abut against the third bend portions  65  before abutting against the contact portion  13  or the second spring portion  17 . 
     Accordingly, the contact  83  according to the third embodiment is configured such that the second spring portion  17  is difficult to damage. 
     Next, a fourth embodiment of this invention will be described with reference to  FIG. 9 . 
     The fourth embodiment is configured such that the two to-be-fixed portions  4  are joined together in the third embodiment. 
     In the fourth embodiment, the same reference numerals as in the third embodiment are assigned to components that achieve the same functions as in the third embodiment and portions different from those of the third embodiment will be mainly described. 
     As shown in  FIG. 9 , a contact  85  according to the fourth embodiment is configured such that two to-be-fixed portions  4  are joined together and that a joining portion therebetween forms a flat plate-shape to-be-fixed portion joining portion  67 . 
     By joining the two to-be-fixed portions  4  together as described above, the to-be-fixed portions  4 , the to-be-fixed portion joining portion  67 , a joining portion  11 , and first spring portions  7  jointly form an integrated frame. 
     Therefore, the contact  85  according to the fourth embodiment can be improved in strength. 
     Further, by providing the flat plate-shape to-be-fixed portion joining portion  67 , when mounting the contact  85  on a connector board  51 , the to-be-fixed portion joining portion  67  can be used as a portion adapted to be in contact with a mounting tool such as a suction pad and thus it is possible to improve the mounting workability. 
     Next, a fifth embodiment of this invention will be described with reference to  FIG. 10 . 
     The fifth embodiment is configured such that a fourth bend portion  69  is further provided between the first bend portion  61  and the third bend portion  65  in the third embodiment. 
     In the fifth embodiment, the same reference numerals as in the third embodiment are assigned to components that achieve the same functions as in the third embodiment and portions different from those of the third embodiment will be mainly described. 
     As shown in  FIG. 10 , a contact  87  according to the fifth embodiment is configured such that each of first spring portions  7  is further provided with a fourth bend portion  69  between a first bend portion  61  and a third bend portion  65 . The fourth bend portion  69  is preferably provided between a first front end portion  9  and a fulcrum bend portion  23  in the front-rear direction. 
     By providing the fourth bend portions  69  as described above, even if a mounting tool, a hand, or the like approaches a contact portion  13  or a second spring portion  17  from the joining portion  11  side, the mounting tool, the hand, or the like may abut against the fourth bend portions  69  before abutting against the contact portion  13  or the second spring portion  17 . 
     Accordingly, the contact  87  according to the fifth embodiment is configured such that the second spring portion  17  is more difficult to damage. 
     Next, a sixth embodiment of this invention will be described with reference to  FIG. 11 . 
     The sixth embodiment is configured such that the to-be-fixed portion  4  is not fixed to the connector board  51  by soldering, but is fixed to a connector body  56  in the first embodiment. 
     In the sixth embodiment, the same reference numerals as in the first embodiment are assigned to components that achieve the same functions as in the first embodiment, thereby omitting a description thereof. 
     As shown in  FIG. 11 , a connector  105  according to the sixth embodiment includes a contact  89  and a connector body  56  as a fixing member that fixes a to-be-fixed portion  4  of the contact  89 . 
     More specifically, the connector body  56  comprises a plate-shape lower wall portion  73  (provided under the contact  89 ) on which the contact  89  is mounted, and a longitudinal wall portion  71  provided to the lower wall portion  73  so as to cover the to-be-fixed portion  4  of the contact  89 . 
     The connector body  56  is made of, for example, a resin and the to-be-fixed portion  4  is fixed to the longitudinal wall portion  71  by insert molding or press fitting. 
     On the other hand, the contact  89  comprises a terminal portion  75  extending rearward (direction B in  FIG. 11 ), i.e. rightward in  FIG. 11 , from the to-be-fixed portion  4  and protruding rightward from the longitudinal wall portion  71 . 
     The connector  105  is configured as follows. The connector body  56  with the contact  89  mounted thereon is moved in a direction E from above a connector board  51  as the other connection object so as to be attached to the connector board  51  and the terminal portion  75  of the contact  89  is connected to a contact point  77  of the connector board  51 , so that the contact  89  and the connector board  51  are electrically connected to each other. 
     As described above, the to-be-fixed portion  4  is not necessarily directly fixed to the connector board  51 , but may be fixed to the resin connector body  56  by insert molding or press fitting. 
     While the preferred embodiments of this invention have been described with reference to the accompanying drawings, this invention is not limited thereto. It is apparent that those skilled in the art can think of various changes and modifications in the category described in the claims and it is understood that those also naturally belong to the technical scope of this invention.