Abstract:
A lever-fit-type connector includes: a first connector; a lever provided on the first connector; and a second connector configured to be fitted with the first connector by an operation of the lever, wherein the lever includes a U-shaped elastic member including: a proximal end portion fixed to the lever; a distal end portion projecting in a vertical direction; a projecting portion projecting in a horizontal direction in the vicinity of the distal end portion; a U-shaped portion disposed between the proximal end portion and the distal end portion; and an engaging portion disposed between the distal end portion and the U-shaped portion, the U-shaped elastic member has a clearance between the proximal end portion and the distal end portion in the horizontal direction, and one of the first and second connectors includes an engaging portion operable to be engaged with the engaging portion of the U-shaped elastic member.

Description:
TECHNICAL FIELD 
     The present invention relates to a lever-fit-type connector structured such that a first connector can be fitted with a second connector by rotating a lever mounted on the first connector. 
     BACKGROUND ART 
     There is a lever-fit-type connector in which, when fitting together male and female connectors respectively having multiple terminals, the fitting operation force is reduced by using a lever. 
     And, when the thus fitted or engaged male and female connectors are removed from each other, a lock lever provided on the lever is pushed to release the engagement (see PTL 1). 
     &lt;Lever-Fit-Type Connector of Patent Reference 1&gt; 
       FIGS. 22(A) and 22(B)  are front views of a lever-fit-type connector disclosed in PTL 1. Specifically,  FIG. 22(A)  shows the fitted state of the male and female connectors before a lever is rotated, and  FIG. 22(B)  shows the fitted state of the male and female connectors after the rotation of the lever is completed. 
     In  FIG. 22(A) , a lever-fit-type connector  100  includes a connector  102  fittable with a partner connector  103  and a lever  101  rotatably supported on the connector  102 , while the lever  101  has a cam groove  101 C engageable with a cam pin  103 C provided on the partner connector  103 . By rotating the lever  101 , the cam groove  101 C and the cam pin  103 C can be engaged with each other to generate cam action, thereby drawing the partner connector  103  toward the connector  102 . The lever  101  includes a lever lock portion  111  ( FIG. 22(B)  which, as will be described below, when the rotation is completed, holds the lever  101  in a rotation prevented state. 
     &lt;Lever Lock Portion  111  of Patent Reference 1&gt; 
     In  FIG. 22(B) , the lever lock portion  111 , which is used to hold the lever  101  in the rotation prevented state at the rotation completed time, includes the following structures respectively in the lever  101  and the connector  102  (or, the partner connector  103 ). 
     The structure on the lever  101  side includes a long elastic piece  111 F flexibly deformable with a fixed end  111 S formed in the end portion of the lever  101  as a fulcrum, an engaging portion  111 K formed in such portion of the long elastic piece  111 F as is distant from the fixed end  111 S, and a releasing projection  111 T formed between the fixed end  111 S and engaging portion  111 K. 
     On the other hand, the lever lock portion  111 , on the connector  102  side, includes a lock receiving piece  102 B extended upwardly from the lower end portion of the connector  102 , and a lock receiving projection  102 K provided on and projected from the connector  102  side distal end of the lock receiving piece  102 B. 
     And, when the rotation of the lever  101  is completed, the engaging portion  111 K and the lock receiving projection  102 K can be engaged with each other. 
     &lt;Releasing Operation of Lever Lock Portion  111 &gt; 
     Next, description will be given of the releasing operation of the lever lock portion  111  with reference to  FIGS. 23(A), 23(B) and 23(C) . 
       FIG. 23(A)  is a section view of the lever lock portion  111  in a state where the lever  101  has completed its rotation. In the state of  FIG. 23(A)  where the lever  101  has completed its rotation, the engaging portion  111 K existing near the distal end of the long elastic piece  111 F formed in the lever  101  has climbed over and has been engaged with the lever lock receiving portion  102 K on the connector  102  side due to the flexing operation of the long elastic piece  111 F, whereby, even when any force to lift the lever  101  upwardly is applied thereto, the lever  101  is prevented from rotating in the reverse direction and thus this engaged state can be maintained. 
     To release the engagement of the lever  101 , the releasing projection  111 T formed in the long elastic piece  111 F may be pushed in the arrow P 1  direction of  FIG. 23(B)  with a forefinger, whereby the engaging portion  111 K is disengaged from the lever lock receiving portion  102 K due to the flexing operation of the long elastic piece  111 F. 
     When the releasing projection  111 T is pushed up in the arrow P 2  direction of  FIG. 23(C)  while it is held with the forefinger, the engaging portion  111 K is caused to climb over the lever lock receiving portion  102 K of the connector  102  and move upwardly thereof, whereby the engagement is released. 
     &lt;Problems Found in Lever Lock Portion  111 &gt; 
     The lever lock portion  111  can secure the necessary flexing amount of the elastic piece without increasing the size of the lever and can provide an enhanced lock feeling effect. However, it has been found that it has two following problems. 
     &lt;First Problem&gt; 
     Since the releasing projection  111 T (point of force) is formed between the fixed end  111 S (fulcrum) and engaging portion  111 K (point of action), the distance from the fixed end  111 S (fulcrum) to the releasing projection  111 T (force point) is short. Thus, to release the engagement of the engaging portion  111 K (point of action), the releasing projection  111 T must be pushed with large force. 
     &lt;Second Problem&gt; 
     Recently, multiple lever-fit-type connectors  100  have been arranged adjacently to each other. However, when other connector is arranged in an area adjoining the lever, the area cannot provide a lateral-direction space allowing the pressing of the releasing projection  111 T, thereby raising a possibility that the engagement cannot be released. 
     Also, in order to avoid this, a space necessary for pushing the releasing projection  111 T must be provided previously, which impairs the freedom of design. 
     CITATION LIST 
     Patent Literature 
     (PTL 1) JP-A-2009-26580 
     SUMMARY OF INVENTION 
     Technical Problem 
     The invention aims at solving the above-mentioned two problems. Thus, it is an object of the invention to provide a lever fit-type connector including a lever lock portion which (1) does not require large pushing force to release the engagement of the engaging portion, and (2) can arrange multiple lever-fit-type connectors  100  adjacently and thus cannot impair the freedom of design. 
     Solution to Problem 
     According to an aspect of the invention, there is provided a lever-fit-type connector comprising: a first connector; a lever provided on the first connector; and a second connector configured to be fitted with the first connector by an operation of the lever, wherein the lever includes a U-shaped elastic member including: a proximal end portion fixed to the lever; a distal end portion projecting in a vertical direction; a projecting portion projecting in a horizontal direction in the vicinity of the distal end portion; a U-shaped portion disposed between the proximal end portion and the distal end portion; and an engaging portion disposed between the distal end portion and the U-shaped portion, the U-shaped elastic member has a clearance between the proximal end portion and the distal end portion in the horizontal direction, and one of the first connector and the second connector includes an engaging portion operable to be engaged with the engaging portion of the U-shaped elastic member of the lever. 
     The clearance may be exposed upwardly from the lever. 
     The first connector may include a boss portion on a side surface, the lever may include: a central portion rotatably mounted on the boss portion of the first connector; and a fulcrum projection provided on one end, the second connector may include: a fit space; and a groove formed in an inner wall of the fit space. In a state that the fulcrum projection of the lever is positioned in the groove of the second connector, by pushing the other end of the lever toward the second connector to rotate lever to cause the fulcrum projection of the lever to act as a fulcrum and to cause the central portion of the first connector to act as a point of action, the first connector may be pushed into the fit space and be fitted with the second connector. 
     Advantageous Effects of Invention 
     According to an aspect of invention, the lever lock portion is a U-shaped long elastic piece extending from the fixed end of the end portion of the lever and making a U-turn to return upwardly and includes the releasing projection formed near the distal end thereof. Therefore, when releasing the engagement of the engaging portion, large pressing force is not necessary. 
     Further, in the case that multiple lever-fit-type connectors  100  are arranged adjacently, a forefinger can be inserted from above into a clearance formed in the horizontal direction between the fixed end and distal end sides of the U-shaped long elastic piece, the distal end of the U-shaped long elastic piece can be moved toward the fixed end by the forefinger while depressing the distal end thereof to thereby release the engagement between the engaging portion and lock receiving projection, and, in this state, the two side surfaces of the operation portion of the lever can be sandwiched and lifted upwardly by a thumb and the forefinger, thereby being able to release the lever lock. 
     Thus, when a space for pushing the releasing projection horizontally exists, the lever lock can be released by pushing the releasing projection horizontally, and when such space does not exists, instead of pushing horizontally, by inserting a finger from above, the lever lock can be released. That is, the lever lock can be released from two directions. On the other hand, the lever-fit-type connector disclosed in PTL 1 cannot realize this. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a lever including a lever lock portion according to the invention. 
         FIG. 2(A)  is a longitudinal section view of a lever-fit-type connector shown in  FIG. 1 , showing a state when it is cut in the longitudinal direction.  FIG. 2(B)  is a partially enlarged view of the lever lock shown in  FIG. 2(A) , showing the releasing direction of the lever lock. 
         FIG. 3(A)  is a perspective view of a first connector with a lever shown in  FIG. 1 , showing a state where it is fitted with a second connector.  FIG. 3(B)  is an enlarged perspective view of the operation portion of the lever shown in  FIG. 3(A) . 
         FIGS. 4(A), 4(B) and 4(C)  show front views of the lever-fit-type connector, explaining the first releasing method (F 1  direction access method) for releasing the connector in  FIG. 3(B) .  FIG. 4(A)  shows a pushing direction in the lock releasing operation,  FIG. 4(B)  shows a lever pushing-up operation, and  FIG. 4(C)  shows the procedure of the first releasing method shown in  FIG. 4(A) , in which (1) shows a state just before start of the releasing operation, (2) shows a state just after start of the releasing operation, and (3) shows a lever pushing-up state. 
         FIGS. 5(A), 5(B) and 5(C)  show front views of the lever-fit-type connector, explaining the second releasing method (F 2  direction access method) for releasing the connector in  FIG. 3(B) .  FIG. 5(A)  shows a pushing direction in the lock releasing operation,  FIG. 5(B)  shows a lever pulling-up operation, and  FIG. 5(C)  shows the procedure of the second releasing method shown in  FIG. 5(A) , in which (1) shows a state just before start of the releasing operation, (2) shows a state just after start of the releasing operation, and (3) shows a lever pulling-up state. 
         FIG. 6(A)  is a front view of the lever-fit-type connector, explaining the lever releasing operation.  FIG. 6(B)  is a plan view thereof, and  FIG. 6(C)  is a front view thereof after release of fit between a first connector with a lever and a second connector, in which the second connector is partially broken. 
         FIG. 7  is a front view of the lever-fit-type connector according to the invention, showing a state before the first and second connectors are fitted with each other. 
         FIG. 8  is a perspective view of the first connector with a lever of the lever-fit-type connector shown in  FIG. 7 . 
         FIG. 9  is a perspective view of the lever of the lever-fit-type connector shown in  FIGS. 1 and 7 , when viewed from the fulcrum projection side thereof. 
         FIG. 10  is a perspective view of the second connector of the lever-fit-type connector shown in  FIG. 7 . 
         FIG. 11  is a perspective view of the second connector shown in  FIG. 10 , showing the housing interiors thereof. 
         FIG. 12( a )  is a plan view of the lever-fit-type connector shown in  FIG. 7 , showing an initial state of the fit thereof,  FIG. 12( b )  is an enlarged view of a temporarily holding contact piece of the lever-fit-type connector shown in  FIG. 12( a ) , and  FIG. 12( c )  is a section view taken along the A-A line shown in  FIG. 12( b ) . 
         FIG. 13( a )  is a plan view of the lever-fit-type connector shown in  FIGS. 12( a ), 12( b )  and  12 (C), showing a state where the first connector is inserted into the deeper side of the second connector,  FIG. 13( b )  is an enlarged view of the temporarily holding contact piece of the lever-fit-type connector shown in  FIG. 13( a ) , and  FIG. 13( c )  is a section view taken along the B-B line shown in  FIG. 13( b ) . 
         FIG. 14( a )  is a plan view of the lever-fit-type connector shown in  FIGS. 13( a ), 13( b ) and 13( c ) , showing a state where the first connector is pushed toward the second connector,  FIG. 14( b )  is an enlarged view of the temporarily holding contact piece of the lever-fit-type connector shown in  FIG. 14( a ) , and  FIG. 14( c )  is a section view taken along the C-C line shown in  FIG. 14( b ) . 
         FIG. 15( a )  is a plan view of the lever-fit-type connector shown in  FIGS. 14( a ), 14( b ) and 14( c ) , showing a state where the rotation prevented state of the lever is released,  FIG. 15( b )  is an enlarged view of the temporarily holding contact piece of the lever-fit-type connector shown in  FIG. 15( a ) , and  FIG. 15( c )  is a section view taken along the D-D line shown in  FIG. 15( b ) . 
         FIG. 16( a )  is a plan view of the lever-fit-type connector shown in  FIGS. 15( a ), 15( b ) and 15( c ) , showing a state where the connectors are temporarily set,  FIG. 16( b )  is an enlarged view of the temporarily holding contact piece of the lever-fit-type connector shown in  FIG. 16( a ) , and  FIG. 16( c )  is a section view taken along the E-E line shown in  FIG. 16( b ) . 
         FIG. 17( a )  plan view of the lever-fit-type connector shown in  FIGS. 16( a ), 16( b ) and 16( c ) , showing a state where the lever starts to rotate,  FIG. 17( b )  is an enlarged view of the temporarily holding contact piece of the lever-fit-type connector shown in  FIG. 17( a ) , and  FIG. 17( c )  is a section view taken along the F-F line shown in  FIG. 17( b ) . 
         FIG. 18( a )  is an enlarged view of the fulcrum projection of the lever-fit-type connector shown in  FIGS. 13( a ), 13( b ) and 13( c ) ,  FIG. 18( b )  is a section view of the lever-fit-type connector shown in  FIG. 18( a ) , showing the position relationship of the terminals thereof, and  FIG. 18( c )  is an explanatory view of the position of the fulcrum projection when the rotation prevented state of the lever of the lever-fit-type connector shown in  FIG. 18( a )  is released. 
         FIG. 19( a )  is an enlarged view of the fulcrum projection of the lever-fit-type connector shown in  FIGS. 14( a ), 14( b ) and 14( c ) ,  FIG. 19( b )  is a section view of the lever-fit-type connector shown in  FIG. 19( a ) , showing the position relation of the terminals thereof, and  FIG. 19( c )  is an explanatory view of the position of the fulcrum projection when the rotation prevented state of the lever of the lever-fit-type connector shown in  FIG. 19( a )  is released. 
         FIG. 20( a )  is an enlarged view of the fulcrum projection of the lever-fit-type connector shown in  FIGS. 16( a ), 16( b ) and 16( c ) ,  FIG. 20( b )  is a section view of the lever-fit-type connector shown in  FIG. 20( a ) , showing the position relation of the terminals thereof, and  FIG. 20( c )  is an explanatory view of the position of the fulcrum projection when the lever of the lever-fit-type connector shown in  FIG. 20( a )  is rotated. 
         FIG. 21( a )  is an enlarged view of the fulcrum projection of the lever-fit-type connector shown in  FIGS. 17( a ), 17( b ) and 17( c ) , and  FIG. 21( b )  is a section view of the lever-fit-type connector shown in  FIG. 21( a ) , showing the position relation of the terminals thereof. 
         FIGS. 22(A) and 22(B)  are front views of a lever-fit-type connector disclosed in PTL 1, in which  FIG. 22(A)  shows a state before the connectors thereof are fitted with each other and  FIG. 22(B)  shows a state where the fit is completed. 
         FIG. 23(A)  is a section view of a lever lock portion, showing a state when the rotation of a lever  101  is completed,  FIG. 23(B)  is a section view thereof showing a state just after the engagement releasing operation is started, and  FIG. 23(C)  is a section view thereof showing a state while the lever  101  is being pushed up. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Before describing a preferred lever lock portion according to the invention, description will be given briefly of the structure of a lever-fit-type connector to which the lever lock portion of the invention is applied. 
     &lt;Structure of Lever-Fit-Type Connector According to the Invention&gt; 
     Description will be given below of a lever-fit-type connector according to the invention with reference to  FIGS. 7 to 21 ( b ). 
     A lever-fit-type connector  10  shown in  FIG. 7  includes a male connector (which is hereinafter called a first connector)  2 , a lever  1  rotatably mounted on the connector housing  20  of the first connector  2 , and a female connector (which is hereinafter called a second connector)  3  containing a connector housing  30  having a fit space  39  into which the first connector  2  can be fitted, in which, by rotating the lever  1 , the first connector  2  is pushed into the deep side of the fit space  39  along a fitting direction K and is thereby fitted with the second connector  3 . 
     &lt;First Connector  2 &gt; 
     The first connector  2 , as shown in  FIGS. 7 and 8 , includes a rectangular connector housing  20  formed of insulating synthetic resin and a terminal (female terminal)  29  ( FIG. 18( b ) ) stored in the connector housing  20 . 
     &lt;Connector Housing  20 &gt; 
     The connector housing  20  includes mutually opposed side surfaces  20   a ,  20   b  and connecting surfaces  20   c ,  20   d  connecting together the end portions of the side surfaces  20   a ,  20   b . In the longitudinal-direction central portions of the side surfaces  20   a ,  20   b , there are formed cylindrical-shaped boss portions  21   a ,  21   b  spaced from each other. The longitudinal direction is a direction perpendicular to the fitting direction K shown in  FIG. 7 . The side surfaces  20   a ,  20   b  respectively include, on their longitudinal-direction ends, trapezoidal-shaped temporarily holding projection portions  22   a ,  22   b  respectively projected from the surfaces of the side surfaces  20   a ,  20   b.    
     &lt;Lever  1 &gt; 
     The lever  1  is made of insulating synthetic resin and, as shown in  FIGS. 5(A)  to  9 , includes a pair of side plates  16   a ,  16   b  disposed parallel to each other with their one-side end portions spaced and separated from each other, and an operation portion  14  connecting the other end portions of the paired side plates  16   a ,  16   b.    
     &lt;Operation Portion  14 &gt; 
     The operation portion  14  is a portion to which a load is applied when rotating the lever  1 , that is, a point of force of the lever  1 . The operation portion  14  includes a lock arm  15  which, in a state where the first connector  2  is fitted with the second connector  3 , can be engaged with the connector housing  30  of the second connector  3 . The lock arm  15 , when engaged with the connector housing  30 , prevents the first connector  2  from moving in a direction to part away from the second connector  3  when unexpected external force is applied to the lever  1 . This will be discussed later specifically. 
     &lt;Side Plates  16   a ,  16   b&gt;   
     The paired side plates  16   a ,  16   b  respectively include fulcrum projections  12  provided on their one-end portions. The fulcrum projections  12 , when positioned within fulcrum projection storing grooves  37  formed in the connector housing  30  of the second connector  3 , are caught in the connector housing  30  to provide the fulcrums of the lever  1 . Also, in the portions that exist nearer to the other end portions than the fulcrum projections  12 , there are formed a pair of boss portion storing holes  11   a ,  11   b  respectively for positioning the boss portions  21   a ,  21   b . The boss portion storing holes  11   a ,  11   b  provide points of action of the lever  1  with respect to the connector housing  20 . 
     Also, the paired side plates  16   a ,  16   b  include temporarily holding contact pieces  13  provided in the lower ends of the other end portions thereof. 
     &lt;Temporarily Holding Contact Piece  13 &gt; 
     The temporarily holding contact pieces  13 , when positioned in such portions as more distant from the second connector  3  than any one of the temporarily holding projection portions  22   a ,  22   b  in the initial stage of fitting of the connectors  2 ,  3 , prevent the lever  1  from rotating toward the second connector  3 . The temporarily holding contact pieces  13  respectively include contact projection portions  13   a  having end faces contactable with the temporarily holding projection portions  22   a ,  22   b , and flexible pieces  13   b  connected to the contact projection portions  13   a  and extending toward the other end portions of the side plates  16   a ,  16   b . Each flexible piece  13   b  is formed to have a smaller thickness than the contact projection portion  13   a  and is easy to flex. Also, the flexible pieces  13   b  extend outwardly along a direction where the paired side plates  16   a ,  16   b  are opposed. 
     &lt;Second Connector  3 &gt; 
     The second connector  3 , as shown in  FIGS. 7 and 10 , is made of insulating synthetic resin and includes a female connector housing  30  having a fit space  39  and terminals (male terminals)  31  stored in the connector housing  30 . The male terminals  31  can be fitted with the terminals (female terminals)  29  of the first connector  2 . 
     &lt;Connector Housing  30 &gt; 
     The connector housing  30  includes mutually opposed side surfaces  30   a ,  30   b , connecting surfaces  30   c ,  30   d  connecting together the end portions of the side surfaces  30   a ,  30   b , and a bottom surface  32  for supporting the terminals  31  provided on the opposite side to the opening of the fit space  39 . The side surfaces  30   a ,  30   b , connecting surfaces  30   c ,  30   d  and bottom surface  32  define the fit space  39 . The side surfaces  30   a ,  30   b  respectively include, in their inner surfaces (inner walls), fulcrum projection guide grooves  36  extending from the upper ends (which mean the ends distant from the bottom surface  32 ) of the inner surfaces toward the deep side of the fit space  39  along the fitting direction, fulcrum projection storing grooves  37  connected to the end portions distant from the above-mentioned upper ends of the fulcrum projection guide grooves  36  and extending in a direction to cross the fulcrum projection guide grooves  36 , and plate-shaped releasing plate portions  35 . 
     &lt;Fulcrum Projection Storing Groove  37 &gt; 
     The fulcrum projection storing grooves  37 , when the lever  1  is rotated, position the fulcrum projections  12  and control them to operate as the fulcrum of the lever  1 . The fulcrum projection storing grooves  37 , as shown in  FIGS. 18( a ) to 21( b ) , include edge walls  38  contactable with the outer edge portions of the fulcrum projections  12 . 
     &lt;Edge Wall  38 &gt; 
     The edge wall  38  includes a first taper wall  38   b  and a second taper wall  38   a  for guiding the fulcrum projection  12  to the first taper wall  38   b . The first taper wall  38   b  inclines in such a manner that it reduces the width of the fulcrum projection storing groove  37  as it parts away from the fulcrum projection guide groove  36 . The second taper wall  38   a  inclines in such a manner that it increases the width of the fulcrum projection storing groove  37  as it parts away from the fulcrum projection guide groove  36 . Also, the fulcrum projection guide groove  36  guides the fulcrum projection  12  until it is positioned in the fulcrum projection storing groove  37 . 
     Due to provision of such second taper wall  38   a , even when the rotation prevented state of the lever  1  is released early, the second taper wall  38   a  can pick up and guide the fulcrum projection  12  to the first taper wall  38   b . Thus, at the time when the rotation prevented state of the lever  1  is released, the fulcrum projection  12  can be positively positioned within the fulcrum projection storing groove  37 . 
     &lt;Plate-Shaped Releasing Plate Portion  35 &gt; 
     The releasing plate portion  35 , as the first connector  2  is made to approach the second connector  3 , moves into the flexible piece  13   b  of the temporarily holding contact piece  13  and flexes the flexible piece  13   b  outwardly along the mutually opposing direction of the paired side plates  16   a ,  16   b , thereby causing the contact projection portion  13   a  to climb over toward the second connector  3  side of the temporarily holding projection portions  22   a ,  22   b . The releasing plate portion  35 , as shown in  FIG. 10 , is formed integrally with a relative wall  34  disposed opposed to the inner surfaces of the side surfaces  30   a ,  30   b.    
     Also, as shown in  FIG. 11 , the releasing plate portion  35 , includes, in its upper end, a taper portion  35   a  formed such that its thickness gradually increases as it goes toward the deep side of the fit space  39  ( FIG. 7 ) along the fitting direction. 
     Here, holding force (temporarily holding force) to be applied from the contact projection portions  13   a  to the temporarily holding projection portions  22   a ,  22   b  in order to hold the lever  1  in the rotation prevented state, that is, the degree of the difficulty of removal of the contact projection portions  13   a  from the temporarily holding projection portions  22   a ,  22   b  depends on the amount of application of the flexible piece  13   b  to the taper portion  35   a ; and, at the time when the flexible piece  13   b  has completely climbed over the taper portion  35   a , the holding force becomes zero. That is, the rotation prevented state of the lever  1  is released. 
     &lt;Operation to be Executed Until Terminals  29 ,  31  in Lever-Fit-Type Connector are Fitted&gt; 
     Now, description will be given below of operations to be executed until the terminals  29 ,  31  of the lever-fit-type connector are fitted with each other. 
     &lt;Step 1&gt; 
     In the lever-fit-type connector  10 , the lever  1  is mounted on the first connector  2  and, with the lever  1  held in the rotation prevented state (see  FIGS. 12( a ) to 12( c ) ), the first connector  2  is inserted into the fit space  39  of the connector housing  30  of the second connector  3  ( FIG. 12( a ) ). 
     &lt;Step 2&gt; 
     As shown in  FIG. 13( a ) , when the first connector  2  is inserted into the connector housing  30  until it can be inserted due to its own weight, as shown in  FIGS. 13( b ) and 13( c ) , the upper end of the taper portion  35   a  of the releasing plate portion  35  advances into the inside of the flexible piece  13   b . In this state, such outer edge portion  12   a  of the fulcrum projection  12  as exists nearest to the one end side of the lever  1 , as shown in  FIG. 18( a ) , is situated above the second taper wall  38   a  in the fitting direction K. That is, the fulcrum projection  12  is situated within the fulcrum projection guide groove  36 . Also, as shown in  FIG. 18( b ) , the terminals  29 ,  31  have not yet been connected to each other. In this state, when the rotation prevented state of the lever  1  is released and thus the lever  1  is rotated, as shown in  FIG. 18( c ) , the fulcrum projection  12  is not pulled into the fulcrum projection storing groove  37  but the lever  1  rotates idly. 
     &lt;Step 3&gt; 
     Next, the operation portion  14  of the lever of the lever-fit-type connector  10 , as shown in  FIG. 14( a ) , is pushed toward the second connector  3 , as shown in  FIGS. 14( b ) and 14( c ) , the taper portion  35   a  advances further inside the flexible piece  13   b , whereby the flexible piece  13   b  is flexed outwardly. 
     &lt;Step 4&gt; 
     When the operation portion  14  is further pushed on, as shown in  FIGS. 15( a ) and 15( b ) , the contact projection portion  13   a  climbs up onto the temporarily holding projection portion  22   b  and, as shown in  FIG. 15( c ) , the flexible piece  13   b  climbs over the taper portion  35   a  completely. 
     Thus, the rotation prevented state of the lever  1  is released. In this state, such outer edge  12   a  of the fulcrum projection  12  as exists nearest to the one end side of the lever  1  is situated below the second taper wall  38   a  in the fitting direction K. That is, the fulcrum projection  12  is positioned within the fulcrum projection storing groove  37 . 
     Also, as shown in  FIG. 19( b ) , the terminals  29 ,  31  are not connected to each other. In this state, when the lever  1  is rotated, as shown in  FIG. 19( c ) , the fulcrum projection  12  is picked up by the second taper wall  38   a  and is pulled into the fulcrum projection storing groove  37 . And, the outer edge portion  12   a  is contacted with the second taper wall  38   a  and thus the fulcrum projection  12  is used to serve as a fulcrum. 
     &lt;Step 5&gt; 
     And, as shown in  FIGS. 16( a ) and 20( a ) , such outer edge  12   a  of the fulcrum projection  12  as exists nearest to the one end side of the lever  1  is situated below the first taper wall  38   b  along the fitting direction K. That is, the fulcrum projection  12  is positioned within the fulcrum projection storing groove  37 . This position is expressed as a state where the connectors  2 ,  3  are temporarily set. This is a state where, as shown in  FIG. 20( b ) , the terminals  29 ,  31  are not connected to each other. In this state, when the lever  1  is rotated, as shown in  FIG. 20( c ) , the outer edge portion  12   a  of the fulcrum projection  12  is contacted with the first taper wall  38   b  and thus the fulcrum projection  12  is used to serve as a fulcrum. 
     &lt;Step 6&gt; 
     When the lever  1  is started to rotate in this manner, as shown in  FIG. 21( a ) , the boss portion storing holes  11   a ,  11   b  provide points of action of the lever  1  to push the boss portions  21   a ,  21   b  into the deep side of the fit space  39  along the fitting direction. Thus, as shown in  FIG. 21( b ) , the terminal  31  is fitted into the terminal  29 , whereby the terminals  29 ,  31  are electrically connected to each other. 
     In the above-mentioned lever-fit-type connector, in the rotation operation of the lever  1  after release of the rotation prevented state, in the process where the lever  1  is rotated along the fitting direction with the fulcrum projection  12  positioned within the fulcrum projection storing groove  36 , the first connector  2  can be connected substantially parallel to the second connector  3 . 
     Thus, according to this lever-fit-type connector, the terminals  29 ,  31  can be smoothly fitted with each other without receiving any unreasonable stress, thereby being able to maintain a close contact state between them with no shaking motion relative to each other. Therefore, the electrically connected state of the terminals  29 ,  31  can also be stabilized. 
     &lt;Structure of Lever Lock Portion  120  of the Invention&gt; 
     Next, description will be given below of the lever lock portion  120  of the invention provided in the above lever-fit-type connector. 
       FIG. 1  is a perspective view of a lever including the lever lock portion  120  of the invention. 
     In  FIG. 1 , the lever  1  includes, on the operation portion  14  side thereof, a lever lock portion  120  for holding the lever in the rotation prevented state when the rotation of the lever is completed. The lever lock portion  120  includes, on the lever  1  side thereof, a U-shaped long elastic piece  121 F, a releasing projection  121 T provided near the distal end of the U-shaped long elastic piece  121 F and projected outwardly therefrom, and an engaging portion  121 K formed between the releasing projection  121 T and the U-shaped portion of the lower end of the U-shaped long elastic piece  121 F. 
     The lever lock portion  120  also includes the following structure (to be discussed later) on the second connector  3  side as well. That is, the structure includes a lock receiving piece  123 B formed to extend upwardly from the lower end portion  123 U of the second connector  3  ( FIG. 6(C) ), and a lock receiving projection  123 K engageable with the engaging portion  121 K, while the lock receiving projection  123 K is formed at the position of the lock receiving piece  123 B where the engaging portion  121 K of the U-shaped long elastic piece  121 F is situated when the rotation of the lever  1  is completed. 
     After release of the engagement of the lever lock portion  120 , by lifting up the operation portion  14  of the lever  1  in the solid-white arrow direction shown  FIG. 6(A) , the fit between the connectors can be released (to be discussed later). 
     &lt;Section View of Lever Lock Portion  120 &gt; 
       FIG. 2(A)  is a longitudinal section view of the lever-fit-type connector of  FIG. 1 , when it is cut vertically along the longitudinal direction. 
     In  FIG. 2(A) , the U-shaped long elastic piece  121 F extends downwardly from the operation portion  14  side fixed end  121 S of the lever  1  and makes a U-turn outwardly to return upwardly again. Near the distal end  121 P of the U-shaped long elastic piece  121 F, there is provided the releasing projection  121 T having an outwardly facing projection shape. The engaging portion  121 K is interposed between the releasing projection  121 T and the U-shaped portion  121 U of the lower end of the U-shaped long elastic piece  121 F. The distal end  121 P of the U-shaped long elastic piece  121 F is prevented against forward movement by an upper end edge portion  14 P. 
     A horizontal-direction clearance T 1  existing between the fixed end  121 S and the distal end  121 P of the U-shaped long elastic piece  121 F is formed to have a size allowing insertion of at least a human forefinger. The clearance T 1  is exposed upwardly from the lever  1 . 
     &lt;Two Methods for Releasing Lever Lock Portion  120  of the Invention&gt; 
     The lever lock portion  120  of the invention is characterized in that two releasing methods can be realized.  FIG. 2(B)  is a partially enlarged view of the lever lock portion  120 , explaining the two methods for releasing the lever lock portion  120  shown in  FIG. 2(A) .  FIG. 3(A)  is a perspective view of the lever-fit-type connector  10 , showing a state the first connector  2  with the lever  1  is fitted with the second connector  3 , and  FIG. 3(B)  is an enlarged perspective view of the lever operation portion shown in  FIG. 3(A) . 
     &lt;First Releasing Method&gt; 
     The first releasing method is an F 1 -direction access method shown in  FIG. 2(B)  and  FIG. 3(B) . 
       FIGS. 4(A), 4(B) and 4(C)  show the front views of the lever-fit-type connector  10  to explain the first releasing method. Specifically,  FIG. 4(A)  is the front view to show a lever pushing direction in the lock releasing operation,  FIG. 4(B)  is the front view to show a lever pushing-up operation, and  FIG. 4(C)  is an enlarged section view of the lever lock portion, showing the procedure of the first releasing method shown in  FIG. 4(A) , in which (1) shows a state just before start of the releasing operation, (2) shows a state just after start of the releasing operation, and (3) shows a lever pushing-up state. 
     In  FIGS. 2(B), 3(B) and 4(A) , when the releasing projection  121 T is pushed from outside in the solid-white arrow F 1  direction using a forefinger, due to the flexing operation of the U-shaped long elastic piece  121 F, the engaging portion  121 K is shifted in the R 1  direction and is disengaged from the lock receiving projection  123 K of the second connector  3  ( FIG. 4(C) ), resulting in the state shown in (2) of  FIG. 4(C) . 
     Further, when the releasing projection  121 T is pushed up upwardly as shown in (3) of  FIG. 4(C)  while being pushed by the forefinger, the lever  1  is rotated in the solid-white arrow direction shown in  FIG. 1  and the first connector is thereby also rotated, whereby the fit between the first connector  2  and second connector  3  can be released with high operation efficiency. Here, of course, the direction of the forefinger shown in  FIGS. 4(B)  and (C) may also be reversed by 180 degrees. 
     &lt;Two Advantages of First Releasing Method&gt; 
     &lt;1 of Two&gt; 
     As described above, according to the first releasing method, the U-shaped long elastic piece  121 F extends downwardly from the fixed end of the end portion of the lever and further makes a U-turn outwardly to return upwardly again and includes the releasing projection (point of force) near the distal end thereof, while the engaging portion (point of action) is formed between the fixed end (fulcrum) and releasing projection (point of force) of the end portion of the lever. This eliminates the need to use large pushing force when releasing the engagement. 
     &lt;2 of Two&gt; 
     Further, according to the first releasing method, since the operation to push the releasing projection  121 T ((1) of  FIG. 4(C) ), the operation to release the engagement of the lever lock ((2) of  FIG. 4(C) ) and the operation to lift up the lever  1  ((3) of  FIG. 4(C) ) can be executed using only the forefinger, the lever operation efficiency can be enhanced. 
     &lt;Second Releasing Method&gt; 
     The second releasing method is an F 2 -direction access method shown in  FIGS. 2(B) and 3(B) . 
       FIGS. 5(A), 5(B) and 5(C)  show the front views of the lever-fit-type connector  10  to explain the second releasing method. Specifically,  FIG. 5(A)  is the front view to show a lever pushing direction in the lock releasing operation,  FIG. 5(B)  is the front view to show a lever pulling-up operation, and  FIG. 5(C)  is an enlarged section view of the lever lock portion, showing the procedure of the second releasing method shown in  FIG. 5(A) , in which (1) shows a state just before start of the releasing operation, (2) shows a state just after start of the releasing operation, and (3) shows a lever pulling-up state. 
     In  FIGS. 2(B), 3(B) and 5(A) , in the second releasing method, the releasing projection  121 T is not pushed in the F 1  direction but the forefinger is moved from outside upwardly in the solid-white arrow F 2  ( FIG. 5(A) ) direction to the distal end  121 P of the U-shaped long elastic piece  121 F as shown in (1) of  FIG. 5(C)  to thereby push it. Thus, the distal end  121 P is moved downward due to the flexing operation of the U-shaped long elastic piece  121 F to release the engagement between the engaging portion  121 K and the lock receiving projection  123 K of the second connector  3 . Further, when the distal end  121 P is moved in the R 1  ( FIG. 2(B) ) direction, that is, toward the fixed end  121 S of the operation portion of the lever  1  while being pressed on by the forefinger, there is obtained a state shown in (2) of  FIG. 5(C) . 
     In this state, when, while the two side plates  14   a ,  14   b  ( FIG. 1 ) of the operation portion  14  of the lever  1  are left sandwiched by a thumb and a middle finger, the operation portion  14  is lifted upwardly as shown in (3) of  FIG. 5(C) , the lever  1  can be rotated in the solid-white arrow direction shown in  FIG. 1  and thus the first connector  2  can also be rotated, whereby the fit between the first connector  2  and second connector  3  can be released. 
     &lt;Two Advantages of Second Releasing Method&gt; 
     &lt;1 of Two&gt; 
     As described above, according to the second releasing method, the U-shaped long elastic piece  121 F extends downwardly from the fixed end of the end portion of the lever and further makes a U-turn outwardly to return upwardly again and includes the releasing projection (point of force) near the distal end thereof, while the engaging portion (point of action) is formed between the fixed end (fulcrum) and releasing projection (point of force) of the end portion of the lever. This eliminates the need to use large pushing force when releasing the engagement. 
     &lt;2 of Two&gt; 
     Further, according to the second releasing method, since the thumb and the middle finger are further used to lift up the lever  1 , although the operation efficiency thereof is slightly lower than that of the first releasing method, even when there is no space for pressing the releasing projection horizontally, the fingers can be inserted from above and thus the fit between the connectors can be conveniently released. In the lever-fit-type connector of PTL 1, the fit cannot be released by inserting the fingers from above. 
     &lt;Fit and Removal Between First and Second Connectors&gt; 
       FIG. 6(A)  is a front view of the lever-fit-type connector, when releasing the lever,  FIG. 6(A)  is a plan thereof, and  FIG. 6(C)  is a front view after release of fit between the first and second connectors. The second connector  3  shown in  FIG. 6(C)  includes a lock receiving piece  123 B extending upwardly from the lower end portion  123 U, and a lock receiving projection  123 K provided on the top portion of the lock receiving piece  123 B. The lock receiving projection  123 K, when the lever  1  rotates, is caused to face the engaging portion  121 K of the U-shaped long elastic piece  121 F and, due to the flexing operation of the U-shaped long elastic piece  121 F, the engaging portion  121 K climbs over the lock receiving projection  123 K, whereby they are engaged with each other. 
     The engagement can be released using any one of the above two releasing methods. 
     After the engagement of the lever lock portion  120  is released, the further lift-up of the lever  1  is carried out according to a normal manner, that is, the lever  1  is lifted up while the two side plates  16   a ,  16   b  of the lever  1  are being sandwiched by the thumb and the middle finger in  FIG. 6(A) . 
     Due to use of the lever  1 , the fit and removal between the first connector  2  and second connector  3  can be carried out using light lifting-up force as shown in  FIG. 6(C) . 
     &lt;Embodiment 2&gt; 
     In the embodiment 1, the lock receiving piece and lock receiving projection are provided on the second connector&#39; side. However, also when they are provided on the first connector&#39; side, the lever lock portion can be realized similarly. 
     &lt;Summary&gt; 
     As described above, the lever lock portion is the U-shaped long elastic piece which extends downwardly from the fixed end of the end portion of the lever and makes a U-turn to return upwardly, and the releasing projection is provided near the distal end of the lever lock portion. Therefore, the engagement of the engaging portion can be released without using large pushing force. 
     Also, when multiple lever-fit-type connectors are arranged adjacently, a forefinger is inserted from above into a clearance formed between the fixed end side and distal end side of the U-shaped long elastic piece in the horizontal direction, the distal end of the U-shaped long elastic piece is moved toward the fixed end by the forefinger while depressing the distal end to thereby release the engagement between the engaging portion and lock receiving projection, and, in this state, the two side surfaces of the operation portion of the lever are sandwiched and lifted upwardly by a thumb and a forefinger, thereby being able to release the lever lock. 
     Therefore, instead of pushing the releasing projection horizontally, by inserting the finger from above, the lever lock can be released although the operation is slightly troublesome. 
     The present application is based on Japanese Patent Application No. 2011-239432 filed on Oct. 31, 2012, the contents of which are incorporated herein by way of reference. 
     REFERENCE SIGNS LIST 
     
         
           1 : Lever 
           2 : First connector 
           3 : Second connector 
           10 : Lever-fit-type connector 
           12 : Fulcrum projection 
           13 : Temporarily holding contact piece 
           14 : Operation portion 
           14 P: Upper end edge portion 
           20   a ,  20   b : Side surface 
           21   a ,  21   b : Boss portion 
           22   a ,  22   b : Temporarily holding projection portion 
           35 : Releasing plate portion 
           35   a : Taper portion 
           36 : Fulcrum projection guide groove 
           37 : Fulcrum projection storing groove 
           39 : Fit space 
         K: Fitting direction 
           120 : Lever lock portion 
           121 F: U-shaped long elastic piece 
           121 K: Engaging portion 
           121 P: Distal end 
           121 S: Fixed end 
           121 T: Releasing projection