Abstract:
The low insertion force type connector has a housing, contacts, shafts, main bodies of the shafts that urge the contacts, cams which maintain the mating connector at a depth that immediately precedes complete engagement, hook-shaped members which perform a gradually increasing locking operation with the mating connector, a lever, and a cover member. After the connectors have been engaged with each other to a depth that immediately precedes complete engagement, the lever is operated so that the cams are released. As a result, an electrical connection between the connectors is established by the main bodies; furthermore, the connectors are caused to approach each other even more closely by the hook-shaped members, so that wiping is performed, and so that the connectors are locked to each other.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a low insertion force type connector, and more specifically relates to a low insertion force type connector that has a locking mechanism that locks in a state of complete engagement with a mating connector. 
     DESCRIPTION OF THE RELATED ART 
     As the number of contacts in a connector increases, and as connectors become so-called multi-pole connectors, the insertion force required for the mating of such connectors increases, so that the mating operation becomes difficult or impossible. Accordingly, low insertion force type electrical connectors known as LIF (low insertion force) connectors or ZIF (zero insertion force) connectors have been developed. 
     The electrical connectors disclosed in Japanese Unexamined Patent Publication No. 59(1984)-139583 and Japanese Unexamined Patent Publication No. 4(1992)-342974 are known as low insertion force type connectors of this type. The former disclosure relates to a zero insertion force type connector; in which fixed connecting terminals and plug terminals are electrically connected via contact parts fastened to a rotating shaft. In the operation of this connector, the plug terminals are first inserted in a state in which the plug terminals are separated from the fixed connecting terminals; next, the contact parts fastened to the rotating shaft are rotated by rotating the rotating shaft, thus causing these contact parts to contact both the plug terminals and the fixed connecting terminals, so that electrical connections are made. 
     Furthermore, the low insertion force type connector of the latter disclosure has an opening means that opens contact parts that are ordinarily in a closed state. After the connector is engaged with the contact parts in an open state so that the contact parts of the other connector are received, the opening means is released so that the contact parts of the two connectors are caused to contact each other. In a state in which the contact parts of the engaged connectors are in contact with each other, the two connectors are slightly separated, and the contact parts are wiped. This wiping is accomplished by using a sliding means. The connector is constructed so that the opening means and sliding means are successively driven by a cam driving member that slides in a rectilinear manner. 
     In both examples of the prior art described above, the engaged state or mated condition of the connectors is maintained by the frictional engaging force of the contacts which are in contact with each other. Accordingly, there is a concern that external forces to which the connectors are subjected may result in faulty contact between the contacts, or in a release of the engaged state of the connectors. Furthermore, in the case of the latter prior art, since a gap is created between the engaging surfaces of the two connectors for the purpose of wiping, it is difficult to judge from the external appearance whether the connectors are properly mated or not. 
     Furthermore, in the former connector, contact parts are required in addition to the rotating shaft in order to obtain a low insertion force, while in the latter connector, respective pluralities of members are required as the opening means and sliding means. 
     SUMMARY OF THE INVENTION 
     One object of the present invention is to provide a low insertion force type connector that is capable of low insertion force engagement accompanied by forcible wiping, that makes it possible to lock the two connectors to each other so that the completely engaged or mated state of the connectors can be confirmed, and that can maintain this completely engaged state by this locking means. 
     Another object of the present invention is to provide a low insertion force type connector which has a reduced number of parts. 
     The low insertion force type connector of the present invention has a housing with a plurality of contacts that contact the terminals of a mating connector. The housing has a contact urging means that urges and deflects the contacts, a separating means that maintains the mating connector which is engaged with the housing at an engagement depth that immediately precedes complete engagement, a locking means that locks the mating connector in a gradually increasing manner, and a driving means that integrally drives the contact urging means, the separating means and the locking means. The driving means being driven at the time of engagement with the mating connector so that the contact urging means causes the contacts to connect with the terminals of the mating connector, the separating means releases the maintenance of the engagement depth that immediately precedes complete engagement, and the locking means locks with the mating connector so that the mating connector is pulled into a state of complete engagement from the engagement depth that immediately precedes complete engagement. 
     The term “low insertion force type connector” also includes ZIF (zero insertion force) type connectors. 
     The driving means may be constructed so that this driving means has a shaft which is rotatably supported on the housing, and an operating member which is connected to this shaft, and so that the contact urging means, separating means and locking means are integrally formed on this shaft. 
     The present invention may be constructed so that the contact driving means is a first cam member that drives the contacts so that these contacts contact the terminals. The separating means is a second cam member that can assume a contact position in which the second cam member contacts the engaging surface of the mating connector immediately prior to the complete engagement therebetween, and a non-contact position in which the second cam member does not contact the engaging surface. The locking means is a hook-shaped member which has an engaging cam surface that engages with a projection on the mating connector so that the connectors relatively approach each other as the shaft rotates. 
     In the low insertion force type connector of the present invention, the housing is equipped with a contact urging means that urges and deflects the contacts, a separating means that ordinarily maintains the mating connector which is engaged with the housing at an engagement depth that immediately precedes complete engagement, a locking means that locks the mating connector in a gradually increasing manner, and a driving means that integrally drives the contact urging means, the separating means and the locking means. Furthermore, at the time of engagement with the mating connector, the driving means is driven so that the contact urging means causes the contacts to connect with the terminals of the mating connector, the separating means releases the maintenance of the engagement depth that immediately precedes complete engagement, and the locking means locks with the mating connector so that the mating connector is pulled into a state of complete engagement from the engagement depth that immediately precedes complete engagement. Accordingly, the present invention has the following effects: 
     Specifically, low insertion force engagement accompanied by forcible wiping can be accomplished as a result of the locking means pulling the mating connector inward from an engagement depth that immediately precedes complete engagement. Furthermore, complete engagement can be confirmed by the locking of the connectors to each other, and the completely engaged state can be maintained by this locking. Moreover, since there is no gap between the engaged connectors, it can be visually confirmed from the outside that the connectors are completely engaged. 
     Furthermore, in a case where the driving means has a shaft which is supported on the housing so that this shaft is free to rotate, and an operating member which is connected to this shaft, and the contact urging means, separating means and locking means are integrally formed on this shaft, the structure is simple, and the number of parts required is reduced. 
     Furthermore, the number of parts required is similarly reduced in a case where the contact urging means is a first cam member which urges the contacts so that these contacts contact the terminals, the separating means is a second cam member which can assume a contact position in which this cam member contacts the engaging surface of the mating connector immediately prior to the complete engagement, and a non-contact position in which this cam member does not contact the engaging surface, and the locking means is a hook-shaped member which has an engaging cam surface that engages with a projection on the mating connector so that the connectors relatively approach each other as the shaft rotates. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front view of the low insertion force type connector of the present invention. 
     FIG. 2 is a plan view of the low insertion force type connector shown in FIG.  1 . 
     FIG. 3 is a side view of the low insertion force type connector shown in FIG.  1 . 
     FIG. 4 is a bottom view of the low insertion force type connector shown in FIG.  1 . 
     FIG. 5 is an enlarged sectional view of the low insertion force type connector along line  5 — 5  in FIG.  1 . 
     FIG. 6 is an enlarged exploded perspective view of the low insertion force type connector shown in FIG.  1 . 
     FIG. 7 is a front view of a mating connector. 
     FIG. 8 is a plan view of the connector shown in FIG.  7 . 
     FIG. 9 is a side view of the connector shown in FIG.  7 . 
     FIG. 10 is a bottom view of the connector shown in FIG.  7 . 
     FIG. 11 is a front view which shows the connector assembly formed by the engagement of the low insertion force type connector of the present invention and the mating connector. 
     FIG. 12 is a side view of the connector assembly shown in FIG.  11 . 
     FIG. 13 is a sectional view of the connector assembly along line  13 — 13  in FIG.  12 . 
     FIG. 14 is an enlarged sectional view of the connector assembly along line  14 — 14  in FIG.  11 . 
     FIG. 15 is an enlarged sectional view of the connector assembly along line  15 — 15  in FIG.  11 . 
     FIG. 16 is an enlarged sectional view of the connector assembly along line  16 — 16  in FIG.  11 . 
     FIG. 17 is an enlarged sectional view (similar to FIG. 14) along line  14 — 14  in FIG. 11, showing the connector assembly in a completely engaged state. 
     FIG. 18 is an enlarged sectional view (similar to FIG. 15) along line  15 — 15  in FIG. 11, showing the connector assembly in a completely engaged state. 
     FIG. 19 is an enlarged sectional view (similar to FIG. 16) along line  16 — 16  in FIG. 11, showing the connector assembly in a completely engaged state. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The preferred embodiments of the low insertion force type connector (hereafter referred to simply as a “connector”) of the present invention will be described in detail with reference to the attached figures. FIG. 1 is a front view of the connector of the present invention, FIG. 2 is a plan view of the connector shown in FIG. 1, FIG. 3 is a side view of the connector shown in FIG. 1, FIG. 4 is a bottom view of the connector shown in FIG. 1, FIG. 5 is an enlarged sectional view of the connector along line  5 — 5  in FIG. 1, and FIG. 6 is an enlarged exploded perspective view of the connector shown in FIG.  1 . The following description will refer to FIGS. 1 through 6. 
     As is shown most clearly in FIGS. 5 and 6, the connector  1  has a rectangular parallelepiped housing  2  which has a recessed part  4 , a contact assembly  6  which is disposed  15  inside the recessed part  4 , shafts  8  which drive this contact assembly  6 , a lever (operating member)  10  which is connected to these shafts  8 , and a cover member  12  which holds these parts inside the recessed part  4 . This housing  2  is formed from metal, e.g., die-cast zinc, etc., in order to provide electromagnetic shielding. Two rectangular openings  16  which extend in the lengthwise direction of the housing  2  are formed parallel to each other in a line in the bottom wall  14  (FIG. 5) of the housing  2 . The inside edges of the respective openings  16  have flanges  40  (FIGS. 5 and 6) that protrude inward facing each other. Supporting walls  17  (FIG. 6) which have a height that is approximately one-half the height of the housing  2  are integrally formed on both end portions of these openings  16 . A separating wall  18  which connects these two supporting walls  17  is integrally formed on the bottom wall  14  between the openings  16 ,  16 . 
     As is shown in FIG. 6, in the upper surfaces of the supporting walls  17  on both end portions of the openings  16 , relief grooves  20  are formed, and curved supporting grooves  22  are also formed adjacent to these relief grooves  20  on both sides of the relief grooves  20  so that these supporting grooves  22  pass through the relief grooves  20  in the elongate direction of the housing  2 . Of the two pairs of supporting grooves  22 , only the pair corresponding to the opening  16  on one side of the connector is shown in FIG. 6. A female threaded portion  23  is formed toward the bottom wall  14  between the two relief grooves  20  in the center of the upper surface of each supporting wall  17 . Spaces  24  are formed on the outsides of the two supporting walls  17 , i.e., on the insides of the end walls  26   a  and  26   b  of the housing  2 . A cut-out  5  which extends downward from the upper edge  4   a  of the recessed part  4  is formed in the end wall  26   b.    
     In the contact assembly  6 , two types of contacts  28  and  30  with different shapes are respectively provided and held by insert molding in an insulating base member  26  which is molded from a synthetic resin. The base member  26  shown is one embodiment; other embodiments can be used without departing from the scope of the invention. The contacts  28  and  30  are formed by stamping and forming elastic copper alloy plates; each of these contacts has a main body  34 , and a board engagement section  32  which extends downward from the main body  34  and is attached to a board (not shown in the figures). The main body  34  is formed so that it bows outward. In the present embodiment, the base member  26  is split into two members with rows of contacts  28  and  30  disposed on each of the two base members  26 . The base members  26  are joined together and aligned by a dovetail engagement (not shown in the figures) at the joining surfaces of the two base members  26 . As the base members  26  are press-fitted in the openings  16  of the housing  2 , they are maintained in position relative to each other. In the alternative, the base member used may also be a single integral base member on which two rows of contacts are disposed. The attachment apertures  39  in the housing  2  shown in FIG. 4 are used to fasten the housing  2  to the board by means of bolts. 
     As shown in FIG. 5, the end portions of the bent main bodies  34  of the respective contacts  28  and  30  of the contact assembly  6  have contact parts  36  that converge inward and further extend rectilinearly. Anchoring end parts  38  of the contact parts  36  are bent further inward. The contact assembly  6  is attached to the housing  2  by mounting the base members  26  in the openings  16 . Specifically, the base members  26  engage the flanges  40  that extend inward and which face each other inside the openings  16 . In the embodiment shown, the board engagement sections  32  protrude downward from the bottom surfaces of the base members  26  as shown in FIGS. 1 and 3. 
     In the embodiment shown, the shafts  8  are formed from a metal material such as stainless steel; however, other materials having the appropriate strength characteristics can be used without departing from the scope of the invention. As shown most clearly in FIG. 6, there are two shafts corresponding to the two pairs of contact rows, with these shafts being respectively disposed between the rows of contacts  28  and  30 . Furthermore, the shafts  8  are omitted from each of the sectional views shown in FIGS. 5,  14 ,  15 ,  17  and  18 . The cross-sectional shapes of the main bodies or first cam members (contact urging means)  7 , formed by insert molding on the respective shafts  8 , form elliptical cams as shown in FIG.  5 . Ordinarily, these main bodies are disposed in a state in which the long diameter of each elliptical cam is oriented in the vertical direction as shown in FIG.  5 . 
     Second cam members (separating means)  44  are formed on both ends of each main body  7 , with reduced-diameter parts  42  being interposed between the main body  7  and the second cam members  44 . Furthermore, hook-shaped members (locking members)  48  are formed further to the outside with separate reduced-diameter parts  46  being interposed between the second cam members  44  and these hook-shaped members  48 . As will be described later, the second cam members  44  have a roughly triangular shape with a rounded periphery. Ordinarily, the portion of each second cam member  44  that is furthest from the axial center, the stopping part  44   a  (FIG.  14 ), is disposed so that his portion faces upward, i.e., toward the mating connector. With the second cam member in this position, the main body  7  or first cam member of each shaft  8  is in the position shown in FIG.  5 . The shafts  8  and the lever  10  attached to the shafts  8  are referred to as the driving mechanism. In the present embodiment, the second cam members  44  are formed as integral parts of the shafts  8 ; however, it would also be possible to use separate cams. Also in the embodiment shown, the hook-shaped members  48  are attached to the end portions of the shafts  8  as separate members. 
     Referring to FIGS. 6 and 16, each of the hook-shaped members  48  has a flat-plate part  50  that pivots together with the corresponding main body  7 , and a claw  52  that extends from this flat-plate part  50  and which has a shape that runs roughly along a circular arc of rotation about the corresponding shaft  8 . The claws  52  are ordinarily in a state in which the tip ends  53  of the claws  52  face upward between the two shafts  8  (FIG.  10 ). Referring back to FIG. 6, gears  54  are formed adjacent to the hook-shaped members  48  on the outsides of the hook-shaped members  48 . Specifically, these gears  54  are formed on both end portions of each shaft  8 , and are formed with a fan shape so that the two shafts  8  engage with each other. The teeth  56  of the gears  54  are formed on the circular arc surface of the fan shape. The lever  10  is attached to the end portion of one of the two shafts  8 , and consists of an arm  10   a  and an operating part  10   b.    
     When the shafts  8  are disposed in specified positions, the reduced-diameter parts  42  and  46  of the respective shafts  8  are carried in the corresponding supporting grooves  22 , and the second cam members  44  are accommodated inside the relief grooves  20 . In this state, the teeth  56  of the gears  54  engage with each other, so that when the lever  10  is turned, the lever  10  moves in linkage with the connected shaft  8 , and the other shaft  8  is also rotated via the gears  54 . The directions of rotation of the shafts  8  in this case are mutually opposite. 
     Referring again to FIG. 6, the insulating cover member  12  will be described. The cover member  12  has a rectangular shape, and has two holding parts  60 ,  60  on its main surface  62  which extend in the elongate direction of the cover member  12  in correspondence with the rows of contacts  28  and  30 . The respective holding parts  60  protrude from the main surface  62 , and are formed as integral parts of the cover member  12 . Numerous slots  64  that extend in the vertical direction are formed in both sides of the holding parts  60  so that said slots  64  are lined up in the elongate direction of the holding parts  60  in positions corresponding to the contact parts  36  of the contacts  28  and  30 . The contact parts  36  of the contacts  28  and  30  face these slots  64 , so that these contact parts  36  can contact the mating terminals. 
     As shown in FIG. 5, spaces  68  which are each split in the center by a separating wall  66  are formed inside the holding parts  60 . Anchoring recesses  70  are formed in the upper parts of these spaces  68 , i.e., in the vicinity of the flat surfaces  61  of the holding parts  60 . Apertures  72  (see FIG. 6) are formed in the center of the cover member  12  (with respect to the width of the cover member  12 ) at both end parts of the holding parts  60 . Elongate rectangular openings  74  are formed adjacent to these apertures  72  on both sides with respect to the widthwise direction of the cover member  12 . Curved grooves  78  which correspond to the above-mentioned supporting grooves  22  are formed in the walls on both sides of the openings  74 , i.e., walls  76  which are separated in the elongate direction of the cover member  12 . The above-mentioned second cam members  44  are disposed in these openings  74 . Furthermore, openings  80  which extend across the width of the cover member  12  are formed in the vicinity of both ends of the cover member  12  to the outside of the openings  74 . The openings  80  are dimensioned to receive the hook-shaped members  48  therein. Connecting parts  82  are provided on both ends of the cover member  12 . A curved recess  86  which accommodates the end portion of the shaft  8  that is connected to the lever  10  is formed in the end wall  84  of one of these connecting parts  82 . 
     In order to attach the cover member  12  to the housing  2 , the cover member  12  is placed in the recessed part  4  of the housing  2 , and bolts  13  are passed through the apertures  72  and fastened in place by being screwed into the female threaded portions  23  of the housing  2 . In this position, as shown in FIG. 5, the anchoring end parts  38  of the above-mentioned contacts  28  and  30  are positioned in the anchoring recesses  70  of the cover member  12 . As a result, the contacts  28  and  30  are placed in a state in which these contacts can flex in the lateral direction, i.e., in the direction perpendicular to the engagement direction, between the base members  26  and the anchoring recesses  70 . Furthermore, the reduced-diameter parts  42  and  46  of the shafts  8  are held by the above-mentioned curved grooves  78  and supporting grooves  22 , so that the shafts  8  are supported inside the housing in a manner that allows the shafts  8  to rotate. Furthermore, the lever  10  protrudes to the outside from the cut-out  5  in the housing  2 , so that the lever  10  can be operated from the outside of the housing  2 . Before the connectors are mated together, the shafts  8  are in the positions shown in FIG.  5 . Specifically, the main bodies  34  and contact parts  36  of the contacts  28  and  30  are positioned as far to the inside as possible. 
     The mating connector  100  that engages with the connector  1  will be described with reference to FIGS. 7 through 10. FIG. 7 is a front view of the connector  100 , FIG. 8 is a plan view of the connector shown in FIG. 7, FIG. 9 is a side view of the connector shown in FIG. 7, and FIG. 10 is a bottom view of the connector shown in FIG.  7 . 
     The connector  100  has contacts  104  and an elongate rectangular housing  102 . Like the housing  2 , the housing  102  is also constructed from a die-cast metal in order to provide electromagnetic shielding. Step parts  108  with a shape that is complementary to that of the above-mentioned connecting parts  82  are formed in both end portions of the engaging part  106  that engages with the connector  1 . Projections  112  which extend in the direction of length of the housing  102  are caused to protrude from the outward-facing end surfaces  110  of the respective step parts  108  in positions corresponding to the above-mentioned two shafts  8 . The board engaging parts  114  of the contacts  104  protrude from the rear part of the connector  100 , i.e., from the lower side in FIG.  7 . Engaging recesses  116  that accommodate the holding parts  60  are formed side by side in the engaging parts  106  in positions corresponding to the holding parts  60  (FIG.  8 ). Furthermore, a key projection  120  (FIG. 9) is formed in the end surface  118  of the housing  102  in a position corresponding to the cut-out  5 . This key projection  120  has a width that allows insertion of the key projection  120  into the cut-out  5  in the housing  2  of the connector  1  when the connectors are engaged with each other. As is shown in FIG. 10, the board engaging parts  114  of the connector  100  are disposed in two rows, and two pairs of these rows are installed. Each of the two boards (not shown in the figures) to which the connector  100  is attached is disposed between a pair of board engaging parts  114 , and is connected to both sides of the boards. Furthermore, the boards are fastened to the connector  100  by means of screws (not shown in the figures) which are passed through the attachment holes  137  of attachment tabs  135 . 
     The initial engaged or mated state of the connector  1  and connector  100  will be described with reference to FIGS. 11 through 16. FIG. 11 is a front view which shows the connector assembly (hereafter referred to simply as an “assembly”)  190  formed by the engagement of the connector  1  of the present invention and the mating connector  100 , FIG. 12 is a side view of the assembly  190  shown in FIG. 11, FIG. 13 is a sectional view of the assembly  190  along line  13 — 13  in FIG. 12, FIG. 14 is an enlarged sectional view of the assembly  190  along line  14 — 14  in FIG. 11, FIG. 15 is an enlarged sectional view of the assembly  190  along line  15 — 15  in FIG. 11, and FIG. 16 is an enlarged sectional view of the assembly  190  along line  16 — 16  in FIG.  11 . 
     FIGS. 11 and 12 show the initial state in which the connectors are engaged with each other; in other words, these figures show a state immediately preceding the complete engagement of the connector  100  and connector  1 . Accordingly, the two connectors  1  and  100  are not completely engaged in this state. In this state, as shown most clearly in FIG. 12, the operating part  10   b  of the lever  10  is positioned on the right side of the housing  2 . In FIG. 12, it is clearly shown that the key projection  120  of the connector  100  has advanced into the cut-out  5  of the connector  1 . The two connectors  1  and  100  can be engaged only in the direction in which the key projection  120  and cut-out  5  engage with each other. 
     In FIG. 13, it is clearly shown that the reduced-diameter parts  42  and  46  of the shafts  8  are disposed inside the supporting grooves  22 , and that the second cam members  44  are disposed in the relief grooves  20 . Furthermore, it is clearly shown that the hook-shaped members  48  and gears  54  are disposed inside the spaces  24  of the housing  2 . 
     Next, the positional relationship of the two connectors in this state, i.e., the state immediately preceding complete engagement of the connector  100  and connector  1 , will be described. As shown in FIG. 14, the second cam members  44  are operable to prevent the mating connector  100  from moving beyond a partial engagement position during mating with the electrical connector  1 . Specifically, when the connector  100  is inserted into the connector  1 , the engaging surface  122  of the connector  100  contacts the stopping parts  44   a  of the second cam members  44  in the contact position, so that the engaging surface  122  of the connector  100  stops in a state in which a gap is left between the connector  100  and the cover member  12  of the connector  1 . A gap G can be visually confirmed between the connector  1  and connector  100  from the outside of the assembly  190 . Furthermore,  130  in the figures indicates a contact holding member that holds the contacts  104 . This contact holding member  130  is fastened to the housing  102  by means of bolts  132 . 
     In the state that immediately precedes complete engagement, the main bodies  7  of the shafts  8  and the contacts  28  and  30  are in the positional relationship shown in FIG.  15 . Specifically, since the long diameters of the main bodies  7  are oriented in the vertical direction, the contacts  28  and  30  are in a state in which these contacts are displaced inward to the maximum extent. Accordingly, the contact parts  36  of the contacts  28  and  30  are also positioned inside the slots  64  without being urged towards the outside of the slots  64 . Meanwhile, the contact parts  126  on the tip ends of the terminals of the inserted connector  100  are in a state of low contact pressure in which these contact parts  126  barely contact the contact parts  36  of the contacts  28  and  30 . Accordingly, only a small insertion force is required in this case. It would also be possible to arrange the system so that absolutely no contact pressure is generated. In other words, it would also be possible for the two connectors to be engaged in a state in which the terminals  104  and contacts  28  and  30  are not in contact. 
     The base members  27  shown in FIG. 15 illustrate a second embodiment of the invention. Specifically, the base members  27  have ribs  27   a  that extend in the elongate direction of the base members  27  on the lower ends of both sides of the base members  27 . These ribs  27   a  are inserted into the openings  19  from below and engage step parts  19   a  of openings  19  in the housing  2 . In the figures referred to in the following description, the connector  1  uses the base members  27  of this second embodiment. 
     The positions of the hook-shaped members  48  in the state immediately preceding complete engagement will be described with reference to FIG.  16 . The hook-shaped members  48  overlap each other in the areas of the claws  52 , and are disposed with the tip ends  53  of the claws  52  facing upward. Accordingly, the engaging spaces  55  that are formed between the flat-plate parts  50  and claws  52  of the hook-shaped members  48  open at the top. In this case, it is important that the projections  112  of the connector  100  be located in positions that are accommodated inside the above-mentioned engaging spaces  55  when the hook-shaped members  48  are rotated. Furthermore, in regard to the square holes  50   a  located in the central portions of the flat-plate parts  50  in the figures, the shapes of the end portions of the shafts  8  are complementary shapes with respect to these square holes  50   a,  and a state is shown in which these end portions and square holes  50   a  are engaged with each other. The members with circular cross sections located to the outside of the square holes  50   a  are spacers  59  which are used to offset the two hook-shaped members  48  in the direction perpendicular to the plane of the page. Moreover, the shafts  8  may also be formed with the same cross-sectional shape from the gear  54  on one end to the gear  54  on the other end. Furthermore, the cross-sectional shape of the shafts  8  may be a shape other than square, such as triangular or hexagonal. 
     Next, the state that results when the lever  10  is turned so that the connectors are completely engaged with each other will be described. FIG. 17 is an enlarged sectional view (similar to FIG. 14) along line  14 — 14  in FIG. 11 showing the assembly  190  in a state in which the shafts  8  have been rotated approximately 90°, i.e., in a completely engaged state. FIG. 18 is an enlarged sectional view (similar to FIG. 15) of the assembly  190  in a case where the shafts  8  have similarly been rotated approximately 90°. FIG. 19 is a sectional view of the assembly  190  along line  16 — 16  (similar to FIG. 16) showing a state in which the shafts  8  have similarly been rotated approximately 90° C., so that the hook-shaped members  48  and projections  112  are engaged. The following description will refer to FIGS. 17 through 19. 
     When the lever  10  is turned approximately 90°, the second cam members  44  also move in linkage with the shafts  8 , so that the second cam members  44  rotate in mutually opposite directions. In this case, the slopping parts  44   a  of the second cam members  44  which have been in contact with the engaging surface  122  of the connector  100  are separated from the engaging surface  122 , and assume a lateral orientation inside the relief grooves  20 . Specifically, the second cam members  44  axe placed in non-contact positions in order to release the mating connector  100  for movement beyond the partial engagement position. Accordingly, the connector  100  can advance further with respect to the connector  1 . As a result of being turned, the lever  10  is placed in a position that is on the opposite side from the position shown in FIG. 14, and the connector  100  shown in FIG. 17 is in a position of complete engagement or mating. 
     Next, the relationship of the contacts  28  and  30  and terminals  104  will be described with reference to FIG.  18 . When the main bodies  7  or first cam members of the shafts  8  rotate approximately 90°, the long diameters of the main bodies  7  are oriented in the lateral direction, and push the main bodies  34  of the contacts  28  and  30  to the outside. As a result, the contact parts  36  of the contacts  28  and  30  are also displaced to the outside, and are urged toward the terminals  104  of the connector  100 , so that these contact parts  36  contact the terminals  104 . As a result, electrical connections are established between the terminals  104  and the contacts  28  and  30 . 
     The locking of the connectors to each other will be described with reference to FIG.  19 . When the projections  112  of the connector  100  begin to advance into the engaging spaces  55  of the hook-shaped members  48  as the shafts  8  rotate, the insides of the claws  52 , i.e., the engaging cam surfaces  57  that form the side edges on the outsides of the engaging spaces  55 , engage with the projections  112 . The engaging cam surfaces  57  are formed so that these cam surfaces  57  approach the centers of the flat-plate parts  50 , i.e., the axial centers of the shafts  8 , as the cam surfaces  57  move further into the engaging spaces  55 . In other words, the engaging cam surfaces  57  are formed with a gradual increase in curvature. Accordingly, the projections  112  are pulled into the connector  1  as the hook-shaped members  48  are rotated. Specifically, the connector  100  is pulled into the connector  1 , and wiping is performed between the terminals  104  and the contacts  28  and  30 ; furthermore, as a result, the connectors are locked in a completely engaged or mated position. The lever  10  can be smoothly turned; when locking occurs, the complete engagement of the connectors with each other can be confirmed as a result of this locking. Furthermore, since the gap G between the connectors shown in FIG. 14 is eliminated, it can be confirmed from the external appearance that the connectors are completely engaged with each other; moreover, the housings  2  and  102  are electrically connected to each other. 
     The present invention was described in detail above; however, the contact urging means may have some other construction. Specifically, it would also be possible to dispose the contact urging means to the outside of the contact rows, and to form the contacts beforehand with a shape that bows outward. The contacts may be arranged so that the contacts are caused to flex inward only when the contacts are urged inward from the outside by the contact urging means. In this case, when the connectors are engaged, the contact urging means operates so that the contacts are caused to flex inward; following the completion of engagement, the contact urging means is released, so that the contacts return outward, thus causing an electrical connection to be established between the connectors. 
     Furthermore, in cases where electromagnetic shielding is not an object, the housing  2  may also be made of a synthetic resin.