Patent Publication Number: US-2002008142-A1

Title: Card connector

Description:
BACKGROUND OF THE INVENTION  
       [0001] 1. Field of the Invention  
       [0002] The present invention relates to card connectors for connecting a card to a circuit board and, particularly, to a card connector for holding a card for a mobile device.  
       [0003] 2. Description of the Related Art  
       [0004] Japanese patent application Kokai No. 11-135192 discloses such a card connector as described above. This card connector comprises a body, a slider pushed into the body along with a card, a spring provided between the slider and the body, and a cam mechanism made up of a cam member and a pin member. The cam mechanism locks the slider. The card is inserted/removed by the “push-push operation” or pushing an edge of the card.  
       [0005] However, the push-push type connector requires a play space in the card insertion direction, increasing the depth of the connector against miniaturization trends. In addition, the sliding length between the card contact and the connector contact is so large that the life of the contacts is cut short. Furthermore, the edge of a card must be protruded from the mobile device so that the card can be damaged or fall out of the connector when the mobile device drops.  
       [0006] To remove the card, it is necessary to apply to the card a pushing force that is greater than the force for insertion of the card, making the card removal difficult. The gripping power of a card is determined by the spring force of the lock mechanism so that it is necessary to replace the lock mechanism for adjusting the gripping power, requiring more labor and cost. The eject member and the lock mechanism are too complex to reduce the size of the device and the manufacturing cost.  
       SUMMARY OF THE INVENTION  
       [0007] Accordingly, it is an object of the invention to provide a card connector that allows miniaturization of the device, improvement in the operability, reduction in the manufacturing cost and the number of parts, and simplification of the structure.  
       [0008] According to the invention there is provided a card connector for electrically connecting to a circuit board a removable card having an engaging recess on a side thereof, which comprises a case for holding the removable card therein; an eject plate biased in a card removal direction for sliding together with the removable card; an engaging member provided on the ejector plate and having an engaging projection for engagement with the engaging recess; a push rod provided outside the eject plate and biased in the card removal direction and having a front portion projecting the case; a cam member biased to move, when the removable card is inserted into a predetermined position, toward the eject plate for engagement with the eject plate to lock the removable card at the predetermined position and, when the push rod is depressed, moved away from the eject plate against the bias to release the eject plate from the engagement.  
       [0009] It is preferred that the cam member comprises an engaging plate for rotation between the case and the push rod and a top column eccentrically provided on the engaging member for engagement with the push rod such that when the removable card is inserted into the predetermined card, it is rotated outwardly while the engaging member is rotated to and engaged with the eject plate to lock the removable card at the predetermined position and, when the push rod is depressed, it is rotated inwardly while the engaging plate is rotated to the eject plate to release the eject plate from the engagement.  
       [0010] The card connector may comprise a spring member for biasing the cam member to the eject plate so that when the removable card is inserted into the case at the predetermined position, the cam member slides to and engages with the eject plate to lock the card at the predetermined position and, when the push rod is depressed, the cam member slides away from the eject plate to release the engagement between the cam member and the eject plate.  
       [0011] It may comprise a push button provided at a rear end of the push rod and biased outwardly so that when the card is not in the case, it is fitted over the rear end of the push rod and, when the card is held in the case, the push rod is moved in the card removal direction and the push button is separated from the rear end and brought into contact with a card detecting switch on a housing.  
       [0012] The push rod may be provided with a restricting member for restricting outward movement of the engaging member with the removable card held in the case. The restricting member may be provided with a stepped down portion having a size changed to adjust changes of the engaging member.  
       [0013] According to another aspect of the invention there is provided a card connector for electrically connecting a removable card to a circuit board, which comprises a case for holding the removable card; an eject plate biased in a card removal direction for sliding together with the removable card; an engaging member provided on the eject plate so as to be laterally flexible and having an engaging projection for engagement with the engaging recess of the removable card; locking means for locking, when the removable card is inserted into the predetermined position, the eject plate at the predetermined position to hold the removable card at the predetermined position; and restricting means for restricting outward movement of the engaging member when the removable card is held at the predetermined position, the restricting means having a stepped portion changed so as to adjust flexure of the engaging member.  
       [0014] When the card is inserted into the case, the cam member is brought to engage the eject plate, holding the card at the predetermined position. When the push rod is depressed, the cam member is brought away from the eject plate to release the engagement with the eject plate. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0015]FIG. 1 is an exploded perspective view of a card connector according to an embodiment of the invention;  
     [0016]FIG. 2 is a perspective view of the card connector;  
     [0017]FIG. 3 is a perspective view of an eject plate for the card connector;  
     [0018]FIG. 4 is a perspective view of a push rod for the card connector;  
     [0019] FIGS.  5 - 7  are perspective views of a lock mechanism for the card connector in action;  
     [0020] FIGS.  8 - 10  are sectional views of the card connector in action;  
     [0021] FIGS.  11 - 13  are perspective views of the card connector in action;  
     [0022]FIG. 14 is a perspective view of a lock mechanism according to another embodiment of the invention;  
     [0023]FIG. 15 is a perspective view of a card connector according to still another embodiment of the invention; and  
     [0024]FIG. 16 is a sectional view of part of a card connector according to yet another embodiment of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
     [0025] In FIGS. 1 and 2, a card connector comprises a case  2  for receiving a removable card  1  (FIGS.  8 - 10 ), an eject plate  3  provided in the case  2  for sliding along with the card  1 , a push rod  4  provided outside the eject plate  3 , and a cam member  5  provided between the push rod  4  and the case  2  for rotation.  
     [0026] The case  2  is made up of a case body  6  made of a synthetic resin, for example, and a case cover  7  made of a metal sheet to cover the case body  6 . The case body  6  has a rectangular bottom plate  8 , a rear wall  9 , a right side wall  10 , and a left side wall  11 . A cut-out  12  is provided in the middle of the left side wall  11 . The front edge of the bottom plate  8  is tapered and a rectangular opening  13  is provided in the middle of the bottom plate  8 . Ten ( 10 ) terminals  14  are arranged in parallel on the bottom plate  8  behind the rectangular opening  13 . The rear end of each terminal  14  is bent upwardly to provide a contact section  15  and the front end is bent downwardly through the rectangular opening  13  to provide a connection section  16 . A first spring mounting groove  17  is provided in the bottom plate  8  at the left rear corner along the left side wall  11  and a circular hole  18  is provided in front of the first spring mounting groove  17 . An abutting section  19  is provided at the left end of the rear wall  9  adjacent to the left side wall  11  and is made higher and thicker than the rest of the rear wall  9 . An obliquely cut portion  20  is provided at the upper right corner of the abutting section  19 . A first spring engaging recess  21  is provided in the left portion of the abutting section  19  corresponding to the first spring mounting groove  17  and a second spring engaging recess  22  is provided above the first spring engaging recess.  
     [0027] The case cover  7  has depending rear and side flanges and a top plate  23  with a rectangular opening  24  provided at a position corresponding to the bottom opening  13 . The top and bottom openings  24  and  13  are used for connecting the connection sections  16  to a circuit board (not shown) and ventilating the heat that is generated during the connecting operation. First and second slits  25  and  26  are provided in the left portion of the top plate  23  aligned in a line in the card insertion/removal direction. A major edge of each slit  25  or  26  is bent downwardly to provide a first or second projection piece  27  or  28 .  
     [0028] The eject plate  3  comprises a slide section  29  extending in the card insertion/removal direction and an engaging plate  30  provided on the rear side face of the slide section  29 . A fine groove  31  and a second spring groove  32  are provided in the top of the slide section  29  to receive the first projection piece  27  and the second spring  33 , respectively. Rear and front depending walls  34  and  35  are provided on the inner side of the slide section  29  with a gap  36  between them. A metallic engaging piece  37  is attached to the outer face of the front depending wall  35  such that a J-shaped engaging projection  38  lies beside the gap  36  and projects inwardly from an imagined line connecting the depending walls  34  and  35 . As FIG. 3 shows, outer and front jaw sections  39  and  40  extend outwardly and forwardly, respectively, from the lower end of the rear depending wall  34  such that their lower faces are flush with the lower face of the engaging section  30 .  
     [0029] The push rod  4  comprises a rear plate  41  for sliding along the rear left side wall  11 , an L-shaped central section  42  for sliding within the gap  12 , and a front rectangular block  43  for sliding along the front left side wall  11  such that the eject plate  3  slides along the rear plate  41  and the central section  42 . A round rod  44  extends rearwardly from the rear end of the rear plate  41  to engage a first spring  45 . As FIG. 4 shows, a step-down portion  46  is provided on the rear section  41  and a guide groove  47  extends outwardly from the inner edge of the step-down portion  46 .  
     [0030] The central section  42  has a sloping inner face  48  tapered toward the rear end and a cut-out portion  49  at its front end. An engaging wall  50  extends outwardly from the central section  42  beyond the rear and front sections  41  and  43  so that the front and rear faces thereof abut against the rear and front ends of the front and rear left side walls  11 , respectively.  
     [0031] The front section  43  is protruded more inwardly than the rear and central sections  41  and  42  and a fine groove  51  extends forwardly from the rear end of the front section  43  to receive the second projecting piece  28 . The front portion  52  of the front section  43  is made thinner than the other portion thereof and a circular recess  53  extends inwardly from the outer face thereof to receive a third spring  55  therein. A removable push button  54  is attached to the front portion  52  is biased outwardly by the third spring  55 . As best shown in FIG. 8, a notch  64  is provided in the case  63 , to which the card connector is attached, beside the push button  54  and a card detecting switch  65  is provided in the notch  64 .  
     [0032] The cam member  5  comprises a short shaft  56  for engagement with the round hole  18 , a semi-circular engaging plate  57 , and a top column  58  eccentrically provided on the engaging plate  57  for engagement with the guide groove  47  such that, as FIGS.  5 - 6 ,  8 , and  10  show, the top column  58  is positioned more rearwardly than the axis of the short shaft  56  with the curved face of the engaging plate  57  facing outwardly and, as FIGS. 7 and 9 show, it is positioned more outwardly than the axis of the short shaft  56  with the curved face of the engaging plate  57  facing forwardly. That is, the top column  58  is positioned inwardly in the guiding groove  47  when the curved face of the engaging plate  57  faces outwardly and outwardly in the guiding groove  47  when the curved face of the engaging plate  57  faces forwardly.  
     [0033] The card  1  will be described below with reference to FIGS.  8 - 10 . The card  1  has a rectangular shape, with a rounded front left corner  59 , and a first engaging recess  60  provided in the lower face of the front left corner  59 . A second engaging recess  61  is provided in the lower face of the card  1  behind the first one, extending inwardly from the left edge of the card  1 . A plurality of contact points  62  are provided on the front edge of the card  1  corresponding to the terminals  14 .  
     [0034] The operation of the card connector will be described below with reference to FIGS.  5 - 10 . Before the card  1  is inserted in the case  2 , the eject plate  3  is pushed forwardly by the second spring  33  so that the front end of the slide section  29  abuts on the rear face of the front section  43  of the push rod  4 . As FIGS. 5 and 8 show, the engaging plate  57  of the cam member  5  is prevented by the outward jaw portion  39  from counterclockwise rotation to keep the curved face to face outwardly. That is, the top column  58  is positioned more forwardly than the axis of the short shaft  56 , keeping the push rod  4  at such a position as shown in FIG. 8 and the push button  54  to engage the case  63 , fitting over the front portion  52 .  
     [0035] As FIG. 8 shows, when the card  1  is inserted into the case  2 , the engaging projection  38  abuts on the left side of the card  1  and engages the second engaging recess  61  and the engaging section  30  engages the first engaging recess  60 . During this time, the eject plate  3  and the push rod  4  keep the initial conditions. When the card  1  is further inserted into the case  2 , the eject plate  3  is moved rearwardly along the push rod  4  along with the card  1  against the second spring  33 .  
     [0036] As FIGS. 7 and 9 show, when the front end of the card  1  abuts on the rear wall  9  and the rear end of the engaging section  30  abuts on the abutment section  19 , the engaging plate  57  rotates counterclockwise and engages the front jaw portion  40 . Consequently, the top column  58  is positioned more outwardly than the axis of the short shaft  56 , the push rod  4  slides forwardly, and the push button  54  is released from the housing  63 . The push button  54  is separated from the front portion  52  by the third spring  55  for contact with the card detecting switch  65 , indicating that the card  1  now is held in the case  2 . At this time, the leftward movement of the engaging plate  37  is restricted by the inner side face of the rear section  41  to lock the engagement between the engaging projection  38  and the second engaging recess  61 .  
     [0037] To eject the card  1  from the case  2 , the push button  54  is depressed to the right against the third spring  55  to fit over the front portion  52  and the push rod  4  pushed rearwardly. As FIG. 10 shows, the top column  58  is moved more rearwardly than the axis of the short shaft  56  and the engaging plate  57  rotates clockwise. Consequently, the curved face of the engaging plate  57  faces outwardly, releasing the engagement between the engaging plate  57  and the front jaw portion  40 . As FIG. 8 shows, the eject plate  3  is moved forwardly together with the card  1  by the second spring  33  along the push rod  4  to the original position. Under this condition, the cut-out portion  49  is positioned on the left side of the engaging projection  38  so that when the card  1  is pulled, the engaging projection  38  is flexed toward the left, releasing the engagement between the engaging projection  38  and the second engaging recess  61  to facilitate the removal of the card  1 .  
     [0038] Another embodiment of the invention will be described below with reference to FIGS.  11 - 14 . The description on structure and operation similar to that of the above embodiment will be omitted. A push rod  71  is provided outside the ejector plate  3  and composed of a rectangular rear section  72  for sliding on the rear left side wall  11 , a central section  73  for sliding in the gap  12 , and a rectangular front section  74  for sliding on the front left side wall  11 . A first spring mounting groove  75  extends forwardly from the rear end of the rear section  72  to receive a first spring  45  therein. An indented portion  76  is provided in the outside of the central section  73  and a leaf spring  77  extends forwardly from the rear end of the indented portion  76 . Alternatively, the leaf spring  77  may extend from the case  1 . A cut-out portion  78  is provided in the front portion of the central section  73  and a wide tapered face  79  is provided on the front end of the cut-out portion  78 .  
     [0039] A guiding ridge  80  extends in the bottom plate  8  of the case body  6  in a direction perpendicular to the card insertion/removal direction and a cam member  81  for sliding along the guiding ridge  80  is biased inwardly by the leaf spring  77 . The cam member  81  has a triangular shape and a sloping front face  82  that has the same slant angle as that of the tapered face  79 .  
     [0040] The operation of this card connector will be described below with reference to FIGS.  11 - 14 . In FIG. 11, before the card is inserted into the case  2 , the eject plate  3  is pressed to the front by the second spring  33  and the cam member  81  abuts on the outside of the slide section  29  so that its movement to the side is restricted.  
     [0041] In FIG. 12, when the card is inserted into the case  2 , the eject plate  3  is moved rearwardly along the push rod  4  against the second spring  33  together with the card. As FIGS. 13 and 14 show, when the card is inserted to a predetermined position, the cam member  81  is moved inwardly along the guiding ridge  80  to engage the front end of the slide section  29  so that forward movement of the eject plate  3  is restricted.  
     [0042] To eject the card  1  from the case  2 , the push rod  71  is depressed against the third spring  55 . The tapered face  79  of the push rod  71  pushes the sloping face  82  of the cam member  81  outwardly against the leaf spring  77  along the guiding ridge  80  so that the engagement between the cam member  81  and the front end of the slide section  29  is released (FIG. 12). The eject plate  3  is moved forwardly together with the card  1  by the second spring  33  to the original position as shown in FIG. 11. When the card is pulled, the engaging projection  38  is flexed to the left so that the engagement between the engaging projection  38  and the second engaging recess  61  is released to eject the card.  
     [0043] As FIG. 15 shows, the engaging plate  30  for engagement with the first engaging recess  60  of the card  1  is replaced by an abutting portion  83  on which the front end of the card  1  abuts. A wrong insertion preventive portion  84  is provided on the rear left corner of the bottom plate  8  to prevent the card  1  from being inserted into the case  2  upside down. The connection sections  16  of terminals  14  extend to the outside.  
     [0044] As FIG. 16 shows, a stepped portion  85  having a length of L and a depth of W is provided in the inside of the rear end portion  41  or  72  of the push rod  4  or  71 . If a force is applied to the card  1  held in the case  2 , the engaging member  37  is flexed to avoid damage to the connector. The amount of flexure of the engaging member  37  is adjusted by changing the length (L) and/or depth (W) of the stepped portion  85 . The portion for restricting the outward movement of the engaging projection  38  and the stepped portion  85  may be provided on the case  2  instead of the push rod  4  or  71 . The card connector according to the invention may be used for a variety of cards including an IC card that is mounted in a mobile device.  
     [0045] As has been described above, the card connector according to the invention requires no space for play that has been required for the push-push operation system. Since the card is locked by the cam member, it does not fall from the connector even if the mobile device is dropped. To remove the card, it is only necessary that the push rod is depressed lightly. Also, it is easy to adjust the force with which the card is held. The structure is simple and the number of parts is so small that the manufacturing cost is reduced.