Abstract:
An electrical connector ( 10 ) comprises a housing ( 11 ), a pair of resilient arms ( 14 ) extending from the housing ( 11 ) for resiliently flexing and deforming, a pair of lock portions ( 15 ) provided through the resilient arms ( 14 ) for engagement with engagement portions ( 40 ) of a mating connector ( 30 ) during a plug-in operation between the electrical connector ( 10 ) and the mating connector ( 30 ), and an operative portion ( 14 B) provided on the resilient arms ( 14 ) and applying an operative force to the resilient arms ( 14 ) so that the resilient arms ( 14 ) flexes and deforms for releasing the engagement between the lock portions ( 15 ) and the engagement portions ( 40 ) of the mating connector ( 30 ).

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     This invention relates to an electrical connector, especially an electrical connector having functions of locking with and unlocking from a mating connector.  
         [0003]     2. Description of the Related Art  
         [0004]     This kind of electrical connector is disclosed in, for example, the below-mentioned Patent Document Number 1. In the Patent Document, an electrical connector comprises a resiliently flexible locking arm extending diagonally from both side faces of a housing. The locking arm has a lock portion, which engages a mating connector, at an intermediate position on the base side thereof in its extension direction, and an operative portion, which releases the engagement with the mating connector, on the free end side thereof.  
         [0005]     When the electrical connector is plugged in the mating connector, the lock portion resiliently flexes to climb over an engagement portion of the mating connector. At the point where the lock portion has climbed over the engagement portion, the lock portion is released from the resilient flexibility so that the locking arm engages the engagement portion, thus completing the lock to prevent the coming off of the electrical connector. For removal of the connector, the locking arm is resiliently flexed toward a side wall of the housing by applying force to the operative portion to release the engagement. Then, the electrical connector is taken out from the mating connector.  
         [0006]     Patent Document No. 1: Japanese Patent Application Unexamined Number 4-35370  
         [0007]     For the purpose of firm locking engagement with the mating connector upon completion of the plug-in operation, the minimum amount of flexibility or displacement of the lock portion is required. In the Patent Document No. 1, since the lock portion is positioned on the base side of the locking arm and the operative portion is positioned on the free end side, the amount of displacement of the operative portion must be larger than that of the lock portion according to the principle of a fulcrum. Consequently, the electrical connector becomes large in the direction of the displacement of the locking arm, and also since the locking arm is long, the electrical connector becomes large in the direction of the extension of the locking arm too.  
         [0008]     Therefore, one of the objectives of the present invention is to provide a small-sized electrical connector with resilient arms having functions of locking engagement and release of the locking engagement.  
       SUMMARY OF THE INVENTION  
       [0009]     According to one aspect of the present invention, an electrical connector comprises a housing, at least one resilient arm extending from the housing and resiliently flexing and deforming, at least one lock portion provided in the resilient arm and engaging an engagement portion of a mating connector during a plug-in between with the mating connector, and an operative portion provided in the resilient arm and applying an operative force to the resilient arm so that the resilient arm flexes and deforms for releasing an engagement between the lock portion and the engagement portion of the mating connector.  
         [0010]     The lock portion is provided in a range same as or overlapped with that of the operative portion in a removal direction of the resilient arm. In the present invention, since the lock portion and the operative portion are provided at the substantially same position in the same direction, even if the lock portion is provided at any positions allowing sufficient amount of the displacement of the lock portion, the amount of the displacement of the operative portion is the same as that of the lock portion. Consequently, the length of the resilient arm can be made small, which results in a small-sized electrical connector.  
         [0011]     The lock portion and the operative portion may be provided in different peripheral faces of the resilient arm. The housing is connected to at least one cable, which extends from the housing at a position different from that of the resilient arm and in a direction perpendicular to a plug-in direction with the mating connector. This structure meets the requirement for a small-sized connector in the plug-in direction.  
         [0012]     It is preferable that the lock portion is made as a projection having a tapered face, which receives, while abutting against the engagement portion of the mating connector, a pushing force from the engagement portion including a component of force in a plug-in direction toward the mating connector. The component of force in the plug-in direction toward the mating connector accelerates the plug-in of the electrical connector into the mating connector.  
         [0013]     It is preferable that the mating connector or a receptacle electrical connector to be plugged in by the electrical connector comprises at least one first cut-off portion provided in a peripheral wall thereof at a position corresponding to that of the resilient arm to permit an insertion of the resilient arm of the electrical connector. Since the resilient arm is inserted into the cut-off portion, a space in the thicknesswise direction of the peripheral wall around the cut-off portion is utilized for accommodating the resilient arm, which makes the connector small in the thicknesswise direction thereof.  
         [0014]     It is preferable that the receptacle electrical connector further comprises at least one second cut-off portion provided at a position corresponding to that of the cable connected to the electrical connector to permit an extension of the cable. Since the cable does not extend in the plug-in direction, the connector can be made small in the plug-in direction.  
         [0015]     In the present invention, the resilient arm can be connected to the electrical connector at a rear position in the plug-in direction and extend forwardly so that at least part of the resilient arm is accommodated in the mating connector during the plug-in. Since the resilient arm does not extend rearwardly, the whole part of the resilient arm falls into the dimension of the connector in the plug-in direction. Also, at least part of the resilient arm falls into the external dimension of the connector in the thicknesswise direction of the resilient arm. Accordingly, the connector can be made small in these directions.  
         [0016]     According to another aspect of the invention, the electrical connector comprises a pair of resilient arms opposing to each other in the displacement direction of the resilient arms, a pair of lock portions provided on both sides of the resilient arms and at least one crimp portion of a terminal for crimping the cable, wherein the crimp portion is provided in a range same as or overlapped with that between the pair of the lock portions in a widthwise direction of the resilient arm. Accordingly, even if the connector receives an external force when an excessive force is applied to the cable, since the lock portions and the engagement portion of the mating connector receive almost all of the external force, the terminal does not receive a large force.  
         [0017]     According to the present invention, since the lock portion and the operative portion are provided at the substantially same position in the extension direction of the resilient arm, a sufficient amount of the displacement of the lock portion and the same amount of the displacement of the operative portion can be obtained. Accordingly, the resilient arm can be made small and the electrical connector becomes small-sized. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]      FIG. 1  is a perspective view of a pair of electrical connectors according to an embodiment of the present invention, showing the condition before a plug-in;  
         [0019]      FIG. 2  is a sectional view of the electrical connectors taken along the line II-II of  FIG. 1 ;  
         [0020]      FIG. 3  is a sectional view of the electrical connectors in the same section as that of  FIG. 2 , showing the condition after the plug-in operation;  
         [0021]      FIG. 4  is a sectional view of the electrical connectors taken along the line IV-IV of  FIG. 1 , showing the condition after the plug-in operation; and  
         [0022]     FIGS.  5 (A),  5 (B), and  5 (C) are sectional views of a resilient arm, and locking and engagement portions of the electrical connectors, showing the condition before the start of the plug-in operation, the condition immediately before the completion of the plug-in operation, and the condition upon or after the completion of the plug-in operation, respectively. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0023]     The embodiments of the present invention will be now described below with the accompanying drawings.  
         [0024]     As shown in  FIGS. 1 and 2 , an electrical connector  10  has two hollows  12  opened to a side face of a housing  11 . A terminal  13  is inserted into each of the hollows  12 . As well shown in  FIG. 4 , the terminal  13  crimps a cable C at an end portion thereof where an external cover C 1  of the cable C is removed by a predetermined length and a core wire C 2  is exposed. The terminal  13  comprises the first hold portion  13 A for holding the external cover C 1 , the second hold portion  13 B for holding the core wire C 2 , a leg portion  13 C for stabling the position and posture of the terminal  13  in the hollow  12 , and a leg-shaped contact portion  13 D for being brought into contact with a contact plate of a mating connector. The first and second hold portions  13 A and  13 B have two legs, respectively, which extend from a U-shaped portion of the terminal  13  for accommodating the cable C. The legs of the first and second hold portions  13 A and  13 B are rounded by crimping process to firmly crimp the external cover C 1  and the core wire C 2  of the cable C, respectively. The leg portion  13 C extends downwardly, that is, extends in a direction receding from the core wire C 2 , and the top edge (lower edge) thereof keeps in touch with the bottom of the hollow  12  to stable the position and posture of the terminal  13 . The contact portion  13 D provided on the top end (right-side end) of the terminal  13  also extends downwardly. As shown in  FIG. 2 , a throat portion  13 D 1 , which is a narrowed portion provided in the contact portion  13 D, is brought into resilient contact with the plate terminal of the mating connector. A lance  13 E is provided on the top of the terminal  13  to engage the housing  11 .  
         [0025]     As shown in  FIG. 4 , the hollow  12  extends from an opening portion  12 A provided in the side face of the housing  11  until the opposite side face in the longitudinal direction of the cable C. A step portion  12 B is provided in the vicinity of the opposite side face. The top end of the terminal  13  abuts against the step portion  12 B to determine the depth of the insertion of the terminal  13  into the hollow  12 . The hollow  12  has a dent portion  12 C in the lower side face of the upper wall of the housing  11 . The dent  12 C engages the lance  13 E of the terminal  13 . The hollow  12  has also slits  12 D and  12 E, which are provided through the lower wall and the opposite side face of the housing  11 , respectively. The slits  12 D and  12 E provide flat spaces in parallel to the sheet of  FIG. 4  to permit the below-mentioned contact portion of the plate terminal of the mating connector to pass through the spaces. The lower part of the slit  12 D is tapered to provide a guide portion  12 D 1  for facilitating the insertion of the contact portion of the mating connector.  
         [0026]     As shown in  FIGS. 1 and 2 , a pair of resilient arms  14  extend downwardly from the upper edges of side walls perpendicular to the side face where the openings  12 A of the hollows  12  are provided. A base portion  14 A connecting the resilient arm  14  and the housing  11  is made thinner than other portions of the resilient arm  14  to provide resilient flexibility and deformation. The resilient arm  14  is of a shape of plate becoming thicker toward the top (lower) end thereof and extends almost up to the lower edge of the housing  11 . That is, the resilient arm  14  stays in the dimension of the housing  11  in the vertical direction. A flat operative portion  14 B is provided in the lower external face of the resilient arm  14 .  
         [0027]     A pair of lock portions  15  projects from both side faces of the resilient arm  14  in the widthwise direction. The lock portions  15  are provided integrally with the resilient arm  14  in a range overlapping with that of the operative portion  14 B in the extension direction of the resilient arm  14 . Also, the two lock portions  15  are provided in a range overlapping with a range between the first and second hold portions  13 A and  13 B in the longitudinal direction of the cable C. It is preferable that the lock portions  15  stay in a range same as or outside the range between the first and second hold portions  13 A and  13 B. The inside face of the lock portion  15  facing the side wall of the housing  11  is flat and the outside face opposed to the inside face is tapered to provide two tapered faces, lower and upper faces  15 A and  15 B. The lower and upper tapered faces  15 A and  15 B are tapered such that the thickness of the lock portion  15  is maximum in the center in the vertical direction and gradually becomes smaller downwardly and upwardly.  
         [0028]     A receiving dent  16  is provided in the lower face of the housing  11 , passing through in the direction perpendicular to the sheet of  FIG. 2 . The receiving dent  16  receives a below-mentioned intermediate wall  42  of the mating connector and has a guide portion  16 A tapered for facilitating the insertion of the intermediate wall  42 . A dent portion  17  is provided in the side face of the housing  11  where the opening portions  12 A of the hollows  12  are provided, passing through in the vertical direction.  
         [0029]     As shown in  FIG. 1 , the mating connector  30  comprises side walls  33 ,  34 ,  35 , and  36  standing upright from the four sides of a bottom wall  32  of a housing  31  and two side walls  34 ′ and  35 ′ lower than the four side walls  33 ,  34 ,  35 , and  36  to define a space for receiving the electrical connector  10  from the upside. Three side walls  34  ( 34 ′),  35  ( 35 ′), and  36  have cut-off portions, which are cut off from the upper edges thereof. Tapered guide portions  33 A,  34 A,  35 A, and  36 A are provided at the upper inside edges of the four side walls  33 ,  34 ,  35 , and  36  for facilitating the insertion of the electrical connector  10 .  
         [0030]     In  FIG. 4 , two apertures  32 A are provided in the bottom wall  32  of the housing  31  in a range corresponding to the slits  12 D of the connector  10 , passing through in the vertical direction. Two leg-shaped connection portions  37 A of the terminal  37  are press-fitted in the apertures  32 A. As shown in  FIG. 2 , the terminal  37  has a shape of plate, which extends in the vertical direction and in the direction perpendicular to the sheet of  FIG. 2 . The terminal  37  comprises the two leg-shaped connection portions  37 A at the lower end thereof and a plate-shaped contact portion  37 B at the upper end thereof. The connection portions  37 A are inserted into and soldered to corresponding holes provided in a circuit board (not shown) outside the housing  31  for electrical connection with the circuit board and for standing up excessive external forces. The contact portion  37 B enters the throat portion  13 D 1  of the terminal  13  of the connector  10 . As shown in  FIGS. 1 and 4 , the contact portion  37 B is provided at right-handed side of the terminal  37  to correspond to the throat portion  13 D 1 . A cut-off portion is provided at the upper left of the contact portion  37 B to provide a space for receiving the connector  10 .  
         [0031]     As shown in  FIGS. 1 and 4 , side apertures  33 B are provided in the side wall  33  to guide and support the plate terminal  37  when the connection portion  37 A of the plate terminal  37  is press-fitted from the upside. A guide portion  33 C is provided at the top edge of each side aperture  33 B for facilitating the insertion of the terminal  37 .  
         [0032]     As shown in  FIG. 1 , a pair of the side walls  34  and  34 ′, and  35  and  35 ′ are provided symmetrically, opposing to each other. Cut-off portions  38  and  39  provided between the side walls  34  and  34 ′, and  35  and  35 ′, respectively, are opened to the upside to receive the resilient arm  14 . Engaging hooks  40  and  41  project to the inside at the side edges of the cut-off portions  38  and  39  and the upper inside of the side walls  34 ,  34 ′,  35 , and  35 ′. The engaging hooks  40  and  41  are provided at positions corresponding to the positions of the lock portions  15  of the resilient arm  14  and furnished with tapered guide portions  40 A and  41 A on the top thereof to make easy the operation upon the start of the engagement.  
         [0033]     Two cut-off portions  36 B are provided in the side wall  36  at positions corresponding to the positions of the two cables C extending from the connector  10  and opened to the upside to receive the cables C. A post  36 C provided between the two cut-off portions  36 B enters the dent portion  17  of the connector  10  from the downside. An intermediate wall  42  extends upwardly and connects the post  36  and the side wall  33  to reinforce the housing  31 . The intermediate wall  42  are inserted into the receiving dent  16  provided in the lower face of the housing  11  of the connector  10 .  
         [0034]     The two connectors  10  and  30  are electrically connected to each other in the following way. The terminal  13 , which has been crimped to the cable C, is inserted into the hollow  12  and the lance  13 E of the terminal  13  engages the dent portion  12 C of the housing  11  to prevent the coming off of the terminal  13 . When the connector  10  is plugged in the connector  30 , the housing  11  is inserted into the space defined by the side walls  33 ,  34 ,  34 ′,  35 ,  35 ′, and  36 . At this point, the terminal  37  of the connector  30  enters the throat portion  13 D 1  of the contact portion  13 D of the terminal  13  of the connector  10  so that that both the terminals  13  and  37  are electrically connected.  
         [0035]     Also, when the connector  10  is plugged in the connector  30 , the cable C of the connector  10  extends from the cut-off portion  36 B of the housing  31  of the connector  30  to the outside, and the resilient arm  14  of the connector  10  enters the cut-off portions  38  and  39  of the connector  30 .  
         [0036]     As shown in  FIG. 5 (A), when the lower tapered face  15 A of the lock portion  15  receives the pushing force from the engagement portion  40  of the connector  30 , the resilient arm  14  is resiliently flexed to the inside to enable the insertion of the connector  10 . As shown in  FIG. 5 (B), when the insertion advances further, the engagement portion  40  abuts against the upper tapered face  15 B. Since the upper tapered face  15 B has a slope reverse to that of the lower tapered face  15 A in respect to the vertical plane, the pushing force applied on the upper tapered face  15 B from the engagement portion  40  generates a downward force, which accelerates the insertion of the connector  10 . Thus, the plug-in between the connectors  10  and  30  is done easily.  
         [0037]     When the insertion advances up to the position where the lock portion  15  passes the engagement portion  40 , the resilient arm  14  is released from the resilient flexibility into the original free condition so that the engagement portion  40  engages the upper end of the lock portion  15  to prevent the coming off of the connector. Namely, the lock is completed.  
         [0038]     When removing the connector  10  from the connector  30 , the user holds the two operative portions  14 B by his or her fingers to apply a pushing force to the resilient arm  14 . The resilient arm  14  is resiliently flexed and deformed and when the amount of the displacement reaches a necessary level, that is, the thickness of the lock portion  15 , the connector  10  becomes ready to be removed. In the present invention, since the resilient arm  14  and the operative portion  14 B are provided at positions overlapping to each other in the removal direction of the resilient arm  14 , the amount of the displacement for the lock and the amount of the displacement of the operative  14 A for the release of the lock become substantially equal.