Abstract:
A low insertion force connector is provided, which includes: a female connector; a male connector to be coupled with the female connector; and an operation lever rotatably attached to the female connector for facilitating coupling and uncoupling of the male and female connectors, the operation lever having an operation plate with grid-like reinforcing ribs crossing lengthwise and crosswise or diagonally on one of front and back surfaces. Thus, the operation plate is strengthened by the grid-like reinforcing ribs enough to facilitate the coupling and uncoupling of the male and female connectors and simultaneously is capable of indicating an operation state of the operation lever with this structural difference between the front and back surfaces.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention generally relates to a low insertion force connector (hereinafter “a LIF connector”) having an operation lever for facilitating coupling and uncoupling of male and female connectors with a plurality of electric terminals and more particularly, to a low insertion force connector which has the operation lever with an operation plate improved in strength and simultaneously having a difference in appearance between the front and back surfaces thereof.  
           [0003]    2. Description of the Related Art  
           [0004]    As a first prior art, FIG. 4 shows a prior art LIF connector disclosed in Japanese Patent Application Laid-open No.5-290921 (hereinafter “JP &#39;921”).  
           [0005]    Referring to FIG. 4, a reference numeral  110  indicates a female connector with a housing  111  provided with receiving portions  112 A, 112 B for male connectors  120 A, 120 B.  
           [0006]    Each of the receiving portions  112 A, 112 B are provided with horizontal guiding grooves  113 , 113  on respective side walls, and the housings  111  are projectingly provided with axial shafts  114  on respective side walls.  
           [0007]    On the other hand, housings  121 A, 121 B of the male connectors  120 A, 120 B are provided with engaging projections  122 , each introduced into the guiding groove  113  of the female connector  110 , on respective side walls. Reference numeral  130  is allotted to the operation lever, and the operation lever  130  consists of three (3) side plates  130 B, 130 C, 130 D each having a circular arc 4 ike cam-groove  131  and a single operation plate  130 A connecting the side plates  130 B, 130 C, 130 D.  
           [0008]    The side plates  130 B, 130 D are provided with respective bearing holes  132  to engage the respective axial shafts  114  so as to rotatably mount the operation lever  130  on the housing  111  of the female connector  110 .  
           [0009]    Firstly, one end of the cam-groove  131  of the operation lever  130  is positioned at an entrance of the guiding groove  113  of the female connector  110 .  
           [0010]    In this state, the male connectors  120 A, 120 B are provisionally inserted into the receiving portions  112 A, 112 B of the female connector  110 , and the engaging projections  122  of the male connectors  120 A, 120 B are simultaneously introduced into both of the guiding grooves  113  and the cam-grooves  131 .  
           [0011]    Then, the engaging projections  122  are led to finishing ends of the guiding grooves  113  and of the cam-grooves  131  by turning the operation lever  130  by approximately 90°, and then the receiving portions  112 A, 112 B are introduced into the male connectors  120 A, 120 B and thereby the male connectors  120 A, 120 B are coupled to the female connector  110 .  
           [0012]    Next, as a second prior art, FIG. 5 shows another prior art LIF connector disclosed in Japanese Patent Application Laid-open No.7-169529 (hereinafter “JP &#39;529”).  
           [0013]    The LIF connector consists of a male connector  210  with female terminals (not shown) and a female connector  220  with male terminals (not shown).  
           [0014]    The male connector  210  is provided with an operation lever  211  formed integrally with a cam  211   a , and the operation lever  211  is rotatably attached to supporting panels  212 , 212  standing on an upper surface of the male connector  210  through an axis  213 . And, two pairs of locking nails  214 , 214  to lock the operation lever  211  in respective turned states differing each other by 180° stand on the upper surface the male connector  210 .  
           [0015]    On the other hand, a driven shaft  221  stands on the female connector  220  in the center thereof. The driven shaft  221  is rotatably linked to the cam  211   a  of the operation lever  211  through a through hole (not shown) in the center of the male connector  210 . According to the above-described structure, the male connector  210  and the female connector  220  are coupled or uncoupled with a vertical movement of the driven shaft  221  caused by rotation of the operation lever  211  by  1800 .  
           [0016]    With respect to the above first prior art LIF connector, however, since the operation plate  130 A of the operation lever  130  is in a plate 4 ike shape with almost the same thickness as of the side plates  130 B, 130 C, 130 D, the operation plate  130 A is very weak and is apt to deform when the male connectors  120 A, 120 B are coupled or uncoupled to the female connector  110 , thereby causing a lowering in operability of the operation lever  130 .  
           [0017]    Also, with respect to the above second prior art LIF connector, since front and back surfaces of the operation lever  211  can not be easily distinguished due to a square bar with flat surfaces, it is difficult at a first glance to judge which state of coupling or uncoupling the operation lever  211  shows, thereby causing a lowering in coupling or uncoupling workability.  
           [0018]    Further, with respect to the above first and second prior art LIF connectors, since the operation plate  130 A of the operation lever  130  and a holding portion of the operation lever  211  are made of smooth surfaces, they are slippery to be handed, thereby causing a lowering of an operability.  
         SUMMARY OF THE INVENTION  
         [0019]    In view of the foregoing, an object of the present invention is to provide a LIF connector having an operation lever with an operation plate improved in strength and simultaneously having a difference in appearance between the front and back surfaces thereof, whereby deformation of the operation plate can be prevented, the operation plate can be held without a slip, and an operation state of the operation lever can be grasped at a glance.  
           [0020]    In order to achieve the above-described object, as a first aspect of the present invention, a low insertion force connector consists of: a female connector; a male connector to be coupled with said female connector; and an operation lever rotatably attached to said female connector for facilitating coupling and uncoupling of said male and female connectors, said operation lever having an operation plate with a structural difference between front and back surfaces thereof, wherein said operation plate is strengthened by said structural difference enough to facilitate said coupling and uncoupling of said male and female connectors and simultaneously is capable of indicating an operation state of said operation lever with said structural difference.  
           [0021]    As a second aspect of the present invention, in the low insertion force connector with the above first aspect, the operation plate is provided with reinforcing ribs on either of the front and back surfaces as the structural difference thereof.  
           [0022]    As a third aspect of the present invention, in the low insertion force connector with the above second aspect, the reinforcing ribs are grid 4 ike nbs crossing lengthwise and crosswise or diagonally.  
           [0023]    As a fourth aspect of the present invention, in the low insertion force connector with the above third aspect, the operation lever has a pair of side plates connected with the operation plate and each provided with a cam-groove; the female connector has a receiving portion to receive the male connector, a through hole communicating with the receiving portion, and a pedestal, surrounding one end opening of the through hole, to rotatably support the operation lever; and the male connector has a driven shaft to be put through the through hole of the female connector and a pair of engaging projections provided on the driven shaft to engage the cam-grooves of the operation lever. According to the above-described structure, since strength of the operation plate is improved by the reinforcing rib, deformation of the operation plate can be surely prevented when the operation lever is operated. And, since the reinforcing ribs distinguish the front and back surfaces of the operation plate of the operation lever, an operation state of the operation lever can be grasped at a glance according to a state, namely front or back, of the operation plate. Further, the operation plate can be held without a slip due to the reinforcing nibs. With the above-described effects, operability of the operation lever can be improved and, therefore, workability for coupling and uncoupling of the male and female connectors can be improved.  
           [0024]    The above and other objects and features of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]    [0025]FIG. 1 is an exploded perspective view showing an embodiment of a LIF connector in accordance with the present invention;  
         [0026]    [0026]FIG. 2A is a sectional view showing an operation lever of the LIF connector of FIG. 1;  
         [0027]    [0027]FIG. 2B is a top view, viewed along an arrow A in FIG. 1, showing the operation lever of FIG. 2A;  
         [0028]    [0028]FIGS. 3A and 3B are partially sectional views showing coupling movement of male and female connectors of the LIF connector of FIG. 1;  
         [0029]    [0029]FIG. 4 is an exploded perspective view showing a first prior art LIF connector; and  
         [0030]    [0030]FIG. 5 is an exploded perspective view showing a second prior art LIF connector.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0031]    An embodiment of the present invention will now be described in further detail with reference to the accompanying drawings.  
         [0032]    [0032]FIG. 1 is an exploded perspective view showing an embodiment of a LIF connector in accordance with the present invention.  
         [0033]    An operation lever in FIG. 1 is shown upside down for indicating a reinforcing rib formed on the back of an operation plate.  
         [0034]    Referring to FIG. 1, the LIF connector of the present embodiment consists of a female connector  10  formed integrally with a housing  1   a  of an electric junction box  1 , a male connector  20  to be accommodated in a rectangular receiving portion  11  of the female connector  10 , and an operation lever  30  attached rotatably on the housing  1   a.    
         [0035]    As shown in FIGS. 1, 3A, and  3 B, the female connector  10  is provided with the receiving portion  11  to receive the male connector  20  and a rectangular through hole  12  communicating with the receiving portion  11  is formed on the top wall of the housing  1   a . The receiving portion  11  is projectingly provided with a plurality of male terminals  13  therein. The male terminals  13  are connected to a busbar (not shown) arranged in the housing  1   a.    
         [0036]    A pedestal  14  surrounding the through hole  12  is formed integrally with an upper surface of the housing  1   a . The pedestal  14  is made up of side walls  14 A, 14 B facing to each other, and axial shaft  14   a  is formed projectingly in the center of each of the side walls  14 A, 14 B. And, a first locking nail  14   b  is provided on one side of each of the side walls  14 A, 14 B, and a second locking nail  14   c  is provided on the other side of each of the side walls  14 A, 14 B. That is, the first locking nail  14   b  and the second locking nail  14   c  are located almost symmetrically with the axial shaft  14   a.    
         [0037]    Further, a stopper  14   d  connected to both of the side walls  14 A, 14 B is formed under the second locking nails  14   c.    
         [0038]    The male connector  20  has a housing  20   a , with a rectangular cross-section, corresponding to the receiving portion  11  of the female connector  10 , and a driven shaft  21 , with a rectangular cross-section, corresponding to the through hole  12  of the female connector  10  stands on an upper surface of the housing  20   a . The driven shaft  21  is provided with a guided projection  21   a  on both sides of the top end.  
         [0039]    The housing  20   a  is provided with a plurality of terminal holes  22  on the top thereof, and a plurality of female terminals  23  to be connected to the male terminals  13  of the female connector  10  are accommodated in the terminal holes  22 .  
         [0040]    Referring to FIG. 1, the operation lever  30  consists of an operation plate  30 A in a rectangular shape and a pair of side plates  30 B, 30 C formed integrally with the operation plate  30 A on both sides thereof.  
         [0041]    As shown in FIGS. 1,2A, and  2 B, the operation plate  30 A is integrally provided with grid-like reinforcing ribs  30   a , crossing lengthwise and crosswise, on the back thereof. The operation plate  30 A is a portion to be held by fingers when the operation lever  30  is turned.  
         [0042]    The reinforcing ribs  30   a  strengthen the operation plate  30 A and prevent the operation plate  30 A from bending.  
         [0043]    The side plates  30 B, 30 C each are provided with both of a shaft receiving groove  31  in a straight shape and a cam-groove  33  in a circular arc-like shape.  
         [0044]    The shaft receiving groove  31  corresponds to the axial shaft  14   a  projecting from the pedestal  14  of the female connector  10  shown in FIG. 1 and has a starting end as an entrance to receive the axial shaft  14   a  and a semicircular finishing end with almost the same diameter as the axial shaft  14   a.    
         [0045]    The shaft receiving groove  31  is integrally provided with a resilient locking portion  32  on the entrance side. The edged end of the locking portion  32  abuts on a periphery of the axial shaft  14   a  so as to hold the axial shaft  14   a  on the side of the finishing end of the shaft receiving groove  31 , thereby rotatably attaching the operation lever  30  on the pedestal  14  of the female connector  10 .  
         [0046]    On the other hand, the cam-groove  33  corresponds to the guided projection  21   a  projecting from the driven shaft  21  of the male connector  20  shown in FIG. 1 and has a starting end as an entrance to receive the guided projection  21   a  and a semicircular finishing end with almost the same diameter as the guided projection  21   a.    
         [0047]    Projecting strips  34  are provided outwardly on both sides of the operation plate  30 A.  
         [0048]    The projecting strips  34  engage the first locking nails  14   b  of the pedestal  14  when the operation lever  30  has been turned in an arrow R direction from a state of FIG. 3B to another state of FIG. 3A, and, on the contrary, engage the first locking nails  14   c  of the pedestal  14  when the operation lever  30  has been turned in an arrow Q direction from the state of FIG. 3A to the state of FIG. 3B.  
         [0049]    Uncoupling operation of the male and female connectors of the LIF connector with the above-escribed structure will be described hereinafter with reference to FIGS. 1,3A, and  3 B.  
         [0050]    In case of coupling the male connector  20  to the female connector  10 , to begin with, the projecting strips  34  are engaged with the first locking nails  14   b  as shown in FIG. 3A by rotating the operation lever  30 , whereby the operation lever  30  is fixed to the pedestal  14  and the entrance of the cam-groove  33  of the operation lever  30  is positioned on the through hole  12  of the female connector  10 .  
         [0051]    Next, the male connector  20  is provisionally inserted in the receiving portion  11  of the female connector  10 , wherein the driven shaft  21  of the male connector  20  projects from the through hole  12  of the female connector  10  and the engaging projections  21   a  each are set at the respective entrances of the cam-grooves  33 .  
         [0052]    From this state, by turning the operation lever  30  in the arrow Q direction with use of the operation plate  30 A, the projecting strips  34  are disengaged from the first locking nails  14   b , the engaging projections  21   a  move along the cam-grooves  33 , and then the male connector  20  is drawn into the receiving portion  11  of the female connector  10 .  
         [0053]    Finally, as shown in FIG. 3B, the engaging projections  21   a  reach the finishing ends of the cam-grooves  33 , that is, the male connector  20  is completely inserted in the receiving portion  11 , whereby the male connector  20  is completely coupled to the female connector  10 . In this state, the male terminals  13  in the female connector  10  are connected to the female terminals  23  in the male connector  20 .  
         [0054]    Simultaneously with the above state, the operation plate  30 A of the operation lever  30  abuts on the stopper  14   d  of the pedestal  14 , while the projecting strips  34  engage the second locking nails  14   c , and then the operation lever  30  is fixed to the pedestal  14 .  
         [0055]    Thus, the male connector  20  and the female connector  10  are kept in a coupled state.  
         [0056]    On the other hand, in case of uncoupling the male connector  20  from the female connector  10 , reversely to the above process, the operation lever  30  is turned in the arrow R direction shown in FIG. 3B with use of the operation plate  30 A, reversely to the above process, and both of the connectors  10 , 20  are to be in the state of FIG. 3A Although the present invention has been fully described by way of examples with reference to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention, they should be construed as being included therein.