Abstract:
Provided is a connector capable of facilitating a work of connecting first and second connection targets. A first receiving part to be coupled to a first plug connector and a second receiving part to be coupled to a second plug connector are formed at the housing of a relay connector which electrically connects the first and second plug connectors to be mounted on a chassis. The housing is provided with a contact which establishes conduction between the first plug connector coupled to the first receiving part and the second plug connector coupled to the second receiving part. The housing comprises a housing body having the first and second receiving parts, and a hook provided at the housing body to engage with a hole provided in the chassis.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a connector. 
   2. Description of the Related Art 
   There is known a plug (connector) which connects a first receptacle (first connection target) mounted on a first flexible board to a second receptacle (second connection target) mounted on a second flexible board (see Japanese Patent Application Laid-Open No. 2003-100394). 
   The plug has a plug body and a jumper lead. 
   The plug body has a first groove area, a second groove area, and a pair of link portions. The first groove area is to be coupled to the first receptacle, and has a plurality of grooves formed therein. The second groove area is to be coupled to the second receptacle, and has a plurality of grooves formed therein. The pair of link portions, which are flexible, couple the first groove area to the second groove area. 
   The jumper lead is a nearly belt-like thin metal plate having leg portions formed at both end portions thereof. The leg portion at one end portion of the jumper lead is inserted into the groove of the first groove area, and the distal end portion of the leg portion protrudes from the groove. The leg portion at the other end portion of the jumper lead is inserted into the groove of the second groove area, and the distal end portion of the leg portion also protrudes from the groove. 
   The plug is fitted in the first and second receptacles in such a way as to cover the first and second receptacles placed at predetermined positions. When the plug is fitted in the first and second receptacles, the distal end portion of the leg portion at one end portion of the jumper lead of the plug is inserted into the groove of the first receptacle to contact the terminal of the first receptacle, and the distal end portion of the leg portion at the other end portion of the jumper lead of the plug is inserted into the groove of the second receptacle to contact the terminal of the second receptacle. As a result, the first receptacle and the second receptacle are connected together. 
   At the time of connecting the first receptacle to the second receptacle with the above-mentioned plug, the first and second flexible boards are placed on a mount target, such as a chassis or a casing, and the plug is fitted in the first and second receptacles mounted on the first and second flexible boards. 
   In contrast thereto, there is a case where a bottom area of the flexible board opposite to the area thereof where the receptacle is mounted is desired to be used as an electronic part mounting area. For example, an LED (Light Emitting Diode) is to be mounted on the entire opposite surface to the surface of the flexible board where the receptacle is mounted. 
   In this case, the plug is placed between the mount target and the first and second flexible boards. 
   Because the plug is not fixed to the mount target, however, the plug may move on the mount target when the plug is fitted in the first and second receptacles of the flexible boards, so that the connecting work cannot be carried out easily. 
   SUMMARY OF THE INVENTION 
   Accordingly, it is an object of the present invention to provide a connector capable of facilitating a work of connecting first and second connection targets. 
   To achieve the object, the present invention provides a connector comprising a housing having a first link portion to which a first connection target to be mounted at a mount target is coupled and a second link portion to which a second connection target to be mounted at the mount target is coupled, and a contact held at the housing to establish conduction between the first connection target coupled to the first link portion and the second connection target coupled to the second link portion, the housing having a housing body having the first and second link portions, and an engagement portion which is provided at the housing body to engage with a to-be-engaged portion provided at the mount target. 
   According to this connector, since the housing has the housing body having the first and second link portions, and the engagement portion which is provided at the housing body to engage with the to-be-engaged portion provided at the mount target, the housing can be fixed to the mount target, so that the connector does not move at the time of connecting the first and second connection targets to the first and second link portions. 
   It is preferable that the to-be-engaged portion should be a hole and the engagement portion should be an elastic hook to be engaged with the hole. 
   The housing preferably has a projection to be inserted, together with the hook, into the hole, to restrict elastic deformation of the hook. 
   It is preferable that the housing body should consist of a first housing body constituting member and a second housing body constituting member which is separate therefrom and independent thereof, each of the first and second housing body constituting members should have the engagement portion, and the contact should connect the first and second housing body constituting members and should have an expanding portion which absorbs relative deviation between the first and second connection targets. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a relay connector according to a first embodiment of the present invention; 
       FIG. 2  is an exploded perspective view of the relay connector shown in  FIG. 1 ; 
       FIG. 3  is a cross-sectional view of the relay connector shown in  FIG. 1 ; 
       FIG. 4  is a perspective view showing a state before the relay connector shown in  FIG. 1  is fixed to a chassis; 
       FIG. 5  is a perspective view showing a state after the relay connector shown in  FIG. 1  is fixed to the chassis; 
       FIG. 6  is a cross-sectional view along line VI-VI in  FIG. 5 ; 
       FIG. 7  is a perspective view showing of a plug connector to be connected to the relay connector shown in  FIG. 1 ; 
       FIG. 8  is an exploded perspective view of the plug connector shown in  FIG. 7 ; 
       FIG. 9  is a perspective view showing a state where the plug connector shown in  FIG. 7  is mounted on a printed board; 
       FIG. 10  is a perspective view showing a state before the plug connector is connected to the relay connector shown in  FIG. 1 ; 
       FIG. 11  is a perspective view showing a state after the plug connector is connected to the relay connector shown in  FIG. 1 ; 
       FIG. 12  is a cross-sectional view showing the state after the plug connector is connected to the relay connector shown in  FIG. 1 ; 
       FIG. 13  is a perspective view of a relay connector according to a second embodiment of the present invention; 
       FIG. 14  is a cross-sectional view of the relay connector shown in  FIG. 13 ; 
       FIG. 15  is a cross-sectional view of the relay connector shown in  FIG. 13 ; 
       FIG. 16  is a perspective view showing a state before the relay connector shown in  FIG. 13  is fixed to a chassis; 
       FIG. 17  is a cross-sectional view showing a state after the relay connector shown in  FIG. 13  is fixed to the chassis; 
       FIG. 18  is a perspective view showing a state after the plug connector is connected to the relay connector shown in  FIG. 17 ; 
       FIG. 19  is a cross-sectional view showing the state after the plug connector is connected to the relay connector shown in  FIG. 17 ; 
       FIG. 20  is a perspective view of a relay connector according to a third embodiment of the present invention; 
       FIG. 21  is an exploded perspective view of the relay connector shown in  FIG. 20 ; 
       FIG. 22  is a cross-sectional view of the relay connector shown in  FIG. 20 ; 
       FIG. 23  is a perspective view showing a state before the relay connector shown in  FIG. 20  is fixed to a chassis; 
       FIG. 24  is a side view showing the state before the relay connector shown in  FIG. 20  is fixed to the chassis; 
       FIG. 25  is a side view showing a state after the relay connector shown in  FIG. 20  is fixed to the chassis; 
       FIG. 26  is a cross-sectional view showing a state before printed boards are fixed to the relay connector shown in  FIG. 20 ; 
       FIG. 27  is a perspective view showing a state where one printed board is connected to the relay connector shown in  FIG. 20 ; and 
       FIG. 28  is a perspective view showing a state where both printed boards are connected to the relay connector shown in  FIG. 20 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Preferred embodiments of the present invention will now be described referring to the accompanying drawings. 
   As shown in  FIGS. 1 to 3 , a relay connector (connector)  1  has a housing  3  and contacts  5 . 
   The housing  3  includes a housing body  31 , hooks (engagement portions)  33 , and projections  35 . 
   The housing body  31  has a first receiving part (first link portion)  311 , a second receiving part (second link portion)  312 , and a fixing part  313 . 
   The first receiving part  311  has nearly the shape of a casing. The first receiving part  311  receives a first plug connector  80 , so that the first plug connector  80  is coupled to the first receiving part  311 . 
   The second receiving part  312  has nearly the shape of a casing. The second receiving part  312  receives a second plug connector  80 ′, so that the second plug connector  80 ′ is coupled to the second receiving part  312 . 
   The fixing part  313 , which has a nearly rectangular parallelepiped shape, couples the first receiving part  311  and the second receiving part  312  together. 
   A plurality of contact retaining grooves  315  are formed in the housing body  31  in a lengthwise direction L of the housing  3  at equal intervals. As shown in  FIG. 3 , the contact retaining groove  315  has a lateral groove portion  315   a , a longitudinal groove portion  315   b  and a longitudinal groove portion  315   c . The lateral groove portions  315   a  are provided at the bottom surfaces of the first and second receiving parts  311 ,  312  and the fixing part  313 , and extend in a widthwise direction W of the housing  3 . The longitudinal groove portions  315   c  are provided at an inner peripheral surface  311   a  of the first receiving part  311 , and extend in a heightwise direction H of the housing  3 . The longitudinal groove portions  315   b  are provided at an inner peripheral surface  312   a  of the second receiving part  312 , and extend in the heightwise direction H of the housing  3 . 
   A plurality of press-in holes  317 ,  318  are formed in the fixing part  313  in the lengthwise direction L thereof at equal intervals. The press-in holes  317 ,  318  extend in the heightwise direction H of the housing  3 . The press-in holes  317 ,  318  communicate with the lateral groove portions  315   a  of the contact retaining grooves  315 . 
   The hooks  33  are provided at the bottom surfaces of both end portions of the first receiving part  311  and at the bottom surfaces of both end portions of the second receiving part  312 . The hook  33  has an arm part  33   a  and a claw  33   b . The arm part  33   a  has a thin plate-like shape and elasticity. The claw  33   b  is coupled to the lower end of the arm part  33   a . The claw  33   b  has a nearly triangular cross-sectional shape. 
   The projections  35  are provided at the bottom surfaces of both end portions of the first receiving part  311  and at the bottom surfaces of both end portions of the second receiving part  312  in such a way as to be adjacent to the respective hooks  33 . There is a clearance between the projection  35  and the hook  33 . The projection  35 , which has a plate-like shape, restricts the elastic deformation of the hook  33  so that the hook  33  does not have excessive elastic deformation. 
   As shown in  FIG. 2 , the contact  5  has a first contact portion  51 , a second contact portion  52 , a link portion  53 , a first press-in portion  54 , and a second press-in portion  55 . 
   The first contact portion  51 , which has a plate-like shape, is placed in the longitudinal groove portion  315   c  of the contact retaining groove  315 . The first contact portion  51  has a contact surface  51   a  protruding from the longitudinal groove portion  315   c  to contact the first plug connector  80  to be described later. 
   The second contact portion  52 , which has a plate-like shape, is placed in the longitudinal groove portion  315   b  of the contact retaining groove  315 . The second contact portion  52  has a contact surface  52   a  protruding from the longitudinal groove portion  315   b  to contact the second plug connector  80 ′ to be described later. 
   The link portion  53 , which has a plate-like shape, couples the first contact portion  51  to the second contact portion  52 , and is placed in the lateral groove portion  315   a  of the contact retaining groove  315 . 
   The first and second press-in portions  54 ,  55 , each of which has a plate-like shape, are coupled to the link portion  53 , and are respectively pressed into the press-in holes  317 ,  318 . The first and second press-in portions  54 ,  55  are respectively pressed into the press-in holes  317 ,  318 , so that the contacts  5  are held in the housing  3 . 
     FIG. 4  is a perspective view showing a state before the relay connector  1  shown in  FIG. 1  is fixed to a chassis  7 ;  FIG. 5  is a perspective view showing a state after the relay connector  1  shown in  FIG. 1  is fixed to the chassis  7 ; and  FIG. 6  is a cross-sectional view along line VI-VI in  FIG. 5 . 
   As shown in  FIG. 4 , a recess  71  which retains the lower portion of the relay connector  1  is formed in the chassis  7  being a mount target on which printed board  9 ,  9 ′ to be described later is to be mounted. Four holes (to-be-engaged portions)  72  are formed at four corners of the bottom surface of the recess  71 . The hook  33  and projection  35  are inserted into the hole  72 . The hole  72  is rectangular, and has a width (long diameter) wider than the widths of the hook  33  and projection  35 , so that clearances are respectively formed between the inner peripheral surface of the hole  72  and the hook  33 , and between the inner peripheral surface of the hole  72  and the projection  35  in the widthwise direction W of the housing  3 . Therefore, the relay connector  1  can move in the widthwise direction W by the clearances over the chassis  7 . 
   To fix the relay connector  1  to the chassis  7 , as shown in  FIG. 4 , the relay connector  1  is positioned so that the hook  33  and projection  35  are positioned above the hole  72 , after which the relay connector  1  is lowered to permit the hook  33  and projection  35  to be inserted into the hole  72 . 
   As a result, the claw  33   b  of the hook  33  is hooked at the peripheral portion of the hole  72  as shown in  FIGS. 5 and 6 , so that the relay connector  1  is fixed to the chassis  7 . 
   When the relay connector  1  is fixed to the chassis  7 , the arm part  33   a  of the hook  33  contacts the inner peripheral surface of the hole  72  in the lengthwise direction L of the housing  3 , but a clearance is formed between the projection  35  and the inner peripheral surface of the hole  72 . Therefore, the relay connector  1  can also move in the lengthwise direction L by the clearance over the chassis  7 . 
     FIG. 7  is a perspective view of the plug connector  80 ,  80 ′ to be connected to the relay connector  1  shown in  FIG. 1 ;  FIG. 8  is an exploded perspective view of the plug connector  80 ,  80 ′ shown in  FIG. 7 ; and  FIG. 9  is a perspective view showing a state where the plug connector  80 ,  80 ′ shown in  FIG. 7  is mounted on the printed board  9 ,  9 ′. 
   As shown in  FIGS. 7 to 9 , the first plug connector (first connection target)  80  has a housing  82 , and contacts  84 . 
   The housing  82  has a housing body  821  and a pair of leg portions  822 ,  823 . The housing body  821  has a rectangular parallelepiped shape. The leg portions  822 ,  823  are coupled to the bottom portion of the housing body  821 . The housing  82  has a plurality of contact retaining spaces  824  formed therein in the lengthwise direction thereof at equal intervals. 
   The contact  84  has a contact portion  841 , a spring portion  842 , a press-in portion  843  and a terminal portion  844 . The contact portion  841  contacts the first contact portion  51  of the contact  5 . The spring portion  842  is coupled to the contact portion  841 . The spring portion  842  presses the contact portion  841  against the first contact portion  51 . The press-in portion  843  is coupled to the spring portion  842 , and is pressed into the housing  82 . The pressing of the press-in portion  843  into the housing  82  causes the contact  84  to be fixed to the housing  82 . The terminal portion  844  is coupled to the press-in portion  843 . 
   The contact  84  is retained in the respective contact retaining space  824  of the housing  82 . The contact portion  841  and terminal portion  844  protrude from the contact retaining space  824 . 
   Fixing pieces  86  are pressed into both end portions of the leg portion  823  of the housing  82 . 
   The terminal portion  844  of the first plug connector  80  and the fixing pieces  86  are soldered to a pad (not shown) of the printed board  9 , so that the first plug connector  80  is mounted on the printed board  9  as shown in  FIG. 9 . 
   Since the second plug connector  80 ′ has a similar structure to that of the first plug connector  80 , the same reference numerals are allotted to omit the description therefor. 
     FIG. 10  is a perspective view showing a state before the plug connector is connected to the relay connector shown in  FIG. 1 ;  FIG. 11  is a perspective view showing a state after the plug connector is connected to the relay connector shown in  FIG. 1 ; and  FIG. 12  is a cross-sectional view showing the state after the plug connector is connected to the relay connector shown in  FIG. 1 . 
   To connect the first plug connector  80  mounted on the first printed board  9  and the second plug connector  80 ′ mounted on the second printed board  9 ′ to the relay connector  1 , the relay connector  1  should be fixed to the chassis  7  beforehand as shown in  FIG. 10 . 
   Next, the first and second plug connectors  80 ,  80 ′ are placed over the first and second receiving parts  311 ,  312  of the relay connector  1  respectively (see  FIG. 10 ). 
   Then, as shown in  FIG. 11 , the first and second plug connectors  80 ,  80 ′ are respectively inserted into the first and second receiving parts  311 ,  312  of the relay connector  1  (see  FIG. 11 ). 
   Since the relay connector  1  is fixed to the chassis  7  at this time, connection of the first and second plug connectors  80 ,  80 ′ to the relay connector l can be carried out easily. 
   Because the relay connector  1  can move on the chassis  7  a little, the positional deviation of the first and second plug connectors  80 ,  80 ′ to the relay connector  1  is absorbed. 
   When the first and second plug connectors  80 ,  80 ′ are inserted into the first and second receiving parts  311 ,  312  of the relay connector  1 , as shown in  FIG. 12 , the contacts  5  contact the contacts  84 ,  84  of the first and second plug connectors  80 ,  80 ′, allowing the first printed board  9  and the second printed board  9 ′ to be electrically connected together via the relay connector  1  and the first and second plug connectors  80 ,  80 ′. 
   According to this embodiment, the relay connector  1  is fixed to the chassis  7 , so that the first and second plug connectors  80 ,  80 ′ can be connected to the relay connector  1  easily. 
   It is also possible to absorb the positional deviation of the first and second plug connectors  80 ,  80 ′ with respect to the relay connector  1 . 
   Further, when the relay connector  1  is fixed to the chassis  7 , the chassis  7  serves as a reinforced plate for the relay connector  1 , thus enhancing the strength of the relay connector  1 . 
   Next, a relay connector (connector)  201  according to a second embodiment of the present invention will be described referring to  FIGS. 13 to 15 . 
     FIG. 13  is a perspective view of a relay connector according to the second embodiment of the present invention;  FIG. 14  is a cross-sectional view of the relay connector shown in  FIG. 13 ; and  FIG. 15  is a cross-sectional view of the relay connector shown in  FIG. 13 . 
   The same reference numerals are allotted to the components in common with those of the first embodiment to omit the description therefor. The following will describe only main differences from the first embodiment. 
   As shown in  FIGS. 13 to 15 , the relay connector  201  is provided with a housing  203  and contacts  205 . 
   The housing  203  consists of a housing body  231 , hooks (engagement portions)  33  and projections  35 . 
   The housing body  231  consists of a first housing body constituting member  231 A and a second housing body constituting member  231 B. The first housing body constituting member  231 A and the second housing body constituting member  231 B are separate from and independent of each other. 
   The first housing body constituting member  231 A has a first receiving part (first link portion)  2311  and a first fixing part  2313 . 
   The first receiving part  2311  has nearly the shape of a casing. The first receiving part  2311  receives a first plug connector  80 , so that the first plug connector  80  is coupled to the first receiving part  2311 . 
   The first fixing part  2313 , which has a nearly rectangular parallelepiped shape, is formed at a side portion of the first receiving part  2311 . 
   A plurality of contact retaining grooves  2315  are formed in the first housing body constituting member  231 A in the lengthwise direction L of the housing  203  at equal intervals. The contact retaining groove  2315  has a lateral groove portion  2315   a , a longitudinal groove portion  2315   b  and a longitudinal groove portion  2315   c  (see  FIG. 15 ). The lateral groove portions  2315   a  are provided at the bottom surface of the first housing body constituting member  231 A, and extend in the widthwise direction W of the housing  203 . The longitudinal groove portions  2315   b  are provided at an inner peripheral surface  2311   a  of the first receiving part  2311 , and extend in the heightwise direction H of the housing  203 . The longitudinal groove portions  2315   c  are provided at the surface of the first fixing part  2313  which faces a second fixing part  2314  to be described later, and extend in the heightwise direction H of the housing  203 . 
   A plurality of press-in holes  2317  are formed in the first fixing part  2313  in the lengthwise direction L of the housing  203  at equal intervals. The press-in holes  2317  extend in the heightwise direction H of the housing  203 . The press-in holes  2317  communicate with the lateral groove portions  2315   a  of the contact retaining grooves  2315 . 
   The second housing body constituting member  231 B has a second receiving part (second link portion)  2312  and a second fixing part  2314 . 
   The second receiving part  2312  has nearly the shape of a casing. The second receiving part  2312  receives the second plug connector  80 ′, so that the second plug connector  80 ′ is coupled to the second receiving part  2312 . 
   The second fixing part  2314 , which has a nearly rectangular parallelepiped shape, is formed at a side portion of the second receiving part  2312 . 
   A plurality of contact retaining grooves  2316  are formed in the second housing body constituting member  231 B in the lengthwise direction L of the housing  203  at equal intervals. The contact retaining groove  2316  has a lateral groove portion  2316   a , a longitudinal groove portion  2316   b  and a longitudinal groove portion  2316   c  (see  FIG. 15 ). The lateral groove portions  2316   a  are provided at the bottom surface of the second housing body constituting member  231 B, and extend in the widthwise direction W of the housing  203 . The longitudinal groove portions  2316   b  are provided at an inner peripheral surface  2312   a  of the second receiving part  2312 , and extend in the heightwise direction H of the housing  203 . The longitudinal groove portions  2316   c  are provided at the surface of the second fixing part  2314  which faces the first fixing part  2313 , and extend in the heightwise direction H of the housing  203 . 
   A plurality of press-in holes  2318  are formed in the second fixing part  2314  in the lengthwise direction L of the housing  203  at equal intervals. The press-in holes  2318  extend in the heightwise direction H of the housing  203 . The press-in holes  2318  communicate with the lateral groove portions  2316   a  of the contact retaining grooves  2316 . 
   The contact  205  has a first contact portion  251 , a second contact portion  252 , a link portion  253 , a first press-in portion  254 , and a second press-in portion  255 . 
   The first contact portion  251 , which has a plate-like shape, is placed in the longitudinal groove portion  2315   b  of the contact retaining groove  2315 . The first contact portion  251  has a contact surface  251   a  protruding from the longitudinal groove portion  2315   b  to contact the first plug connector  80 . 
   The second contact portion  252 , which has a plate-like shape, is placed in the longitudinal groove portion  2316   b  of the contact retaining groove  2316 . The second contact portion  252  has a contact surface  252   a  protruding from the longitudinal groove portion  2316   b  to contact the second plug connector  80 ′. 
   The link portion  253 , which has a plate-like shape, couples the first contact portion  251  to the second contact portion  252 . The link portion  253  has an expanding portion  253   a  curved in a nearly U shape. The expanding portion  253   a  couples the first and second housing body constituting members  231 A,  231 B, and absorbs a relative deviation between the first and second plug connectors  80 ,  80 ′. The link portion  253  is placed in the lateral groove portions  2315   a ,  2316   a  of the contact retaining grooves  2315 ,  2316 , excluding the expanding portion  253   a . The expanding portion  253   a  is placed in the longitudinal groove portions  2315   c ,  2316   c  of the contact retaining grooves  2315 ,  2316  in an elastically deformable manner. 
   The first and second press-in portions  254 ,  255  are each coupled to the link portion  253 , and are respectively pressed into the press-in holes  2317 ,  2318 . The first and second press-in portions  254 ,  255  are respectively pressed into the press-in holes  2317 ,  2318 , so that the contacts  205  are held in the first and second housing body constituting members  231 A,  231 B. 
     FIG. 16  is a perspective view showing a state before the relay connector  201  shown in  FIG. 13  is fixed to the chassis  7 ; and  FIG. 17  is a cross-sectional view showing a state after the relay connector  201  shown in  FIG. 13  is fixed to the chassis  7 . 
   To fix the relay connector  201  to the chassis  7 , as shown in  FIG. 16 , the relay connector  201  is positioned with respect to the chassis  7  so that the hook  33  and projection  35  of the relay connector  201  are positioned above the hole  72  of the chassis  7 , after which the hook  33  and projection  35  of the relay connector  201  are inserted into the hole  72  of the chassis  7 . 
   As a result, the claw  33   b  of the hook  33  of the relay connector  201  is engaged with the peripheral portion of the hole  72  of the chassis  7  as shown in  FIG. 17 , so that the relay connector  201  is fixed to the chassis  7 . 
   When the relay connector  201  is fixed to the chassis  7 , the arm part  33   a  of the hook  33  contacts the inner peripheral surface of the hole  72 , but a clearance is formed between the projection  35  and the inner peripheral surface of the hole  72 . Therefore, the relay connector  201  can move by the clearance over the chassis  7 . Because the first housing body constituting member  231 A and the second housing body constituting member  231 B are coupled by the expanding portions  253   a  of the contacts  205 , they can move separately. 
     FIG. 18  is a perspective view showing a state after the plug connectors  80 ,  80 ′ are connected to the relay connector  201  shown in  FIG. 17 ; and  FIG. 19  is a cross-sectional view showing the state after the plug connectors  80 ,  80 ′ are connected to the relay connector  201  shown in  FIG. 17 . 
   To connect the first plug connector  80  mounted on the first printed board  9  and the second plug connector  80 ′ mounted on the second printed board  9 ′ to the relay connector  201 , the relay connector  201  should be fixed to the chassis  7  beforehand (see  FIG. 17 ). 
   Next, the first and second plug connectors  80 ,  80 ′ are placed over the first and second receiving parts  2311 ,  2312  of the relay connector  201  respectively (see  FIG. 16 ). 
   Then, as shown in  FIG. 18 , the first and second plug connectors  80 ,  80 ′ are respectively inserted into the first and second receiving parts  2311 ,  2312  of the relay connector  201 . 
   Since the relay connector  201  is fixed to the chassis  7 , connection of the first and second plug connectors  80 ,  80 ′ to the relay connector  201  can be carried out easily. 
   Because the first and second housing body constituting members  231 A,  231 B can move on the chassis  7  a little independently of each other, the deviation of the first plug connector  80  with respect to the first housing body constituting member  231 A and the deviation of the second plug connector  80 ′ with respect to second housing body constituting member  231 B are absorbed. 
   When the first and second plug connectors  80 ,  80 ′ are inserted into the first and second receiving parts  2311 ,  2312  of the relay connector  201 , as shown in  FIG. 19 , the contacts  205  contact the contacts  84 ,  84  of the first and second plug connectors  80 ,  80 ′, allowing the first printed board  9  and the second printed board  9 ′ to be electrically connected together via the re′ ay connector  201  and the first and second plug connectors  80 ,  80 ′. 
   According to this embodiment, which achieves similar effects to those of the first embodiment, the first housing body constituting member  231 A and the second housing body constituting member  231 B are coupled together by the expanding portion  253   a , so that larger deviations of the first and second plug connectors  80 ,  80 ′ with respect to the relay connector  201  can be absorbed. Particularly, larger deviations of the first and second plug connectors  80 ,  80 ′ with respect to the relay connector  201  in the widthwise direction W of the housing  203  can be absorbed. 
   Next, a relay connector  3101  according to a third embodiment of the present invention will be described referring to the accompanying drawings. 
     FIGS. 20 to 28  are diagrams showing the relay connector according to the third embodiment of the present invention. 
   The same reference numerals are allotted to the components in common with those of the first and second embodiments to omit the description therefor. The following will describe only main differences from the first and second embodiments. 
   While the relay connectors  1 ,  201  according to the first and second embodiments are each connected to the first and second printed boards  9 ,  9 ′ via the first and second plug connectors  80 ,  80 ′, the relay connector  3101  according to this embodiment is directly connected to a first printed board  1110  and a second printed board  1120 . 
   As shown in  FIGS. 20 to 22 , the connector  3101  is provided with a housing  3103  and contacts  3130 ,  3150 . 
   The housing  3103  has a housing body  3104 , hooks (engagement portions)  33 , and projections  35 . 
   The housing body  3104  consists of a first housing body constituting member  3110 , and a second housing body constituting member  3120 . 
   The first housing body constituting member  3110  has a base plate  3111  and a plurality of insertion portions  3112  (first link portions), positioning protrusions  3113  and a side wall portion  3114 . 
   The base plate  3111  has a nearly plate-like shape, and has a support surface  3111   a  which supports an end portion of the first printed board (first connection target)  1110  (see  FIG. 27 ). 
   The insertion portions  3112 , which are nearly columnar, are formed on the support surface  3111   a  of the base plate  3111 . The distal end of each insertion portion  3112  is formed into a nearly tapered shape. The insertion portions  3112  are aligned in two rows in a lengthwise direction L 1  of the first housing body constituting member  3110  at equal intervals. One row of the insertion portions  3112  is shifted from the other row of the insertion portions  3112  by a half pitch in the lengthwise direction L 1 . 
   The positioning protrusions  3113  are formed at both end portions of the support surface  3111   a  of the base plate  3111 . 
   The side wall portion  3114  is formed at the peripheral portion of the support surface  3111   a  of the base plate  3111 . 
   The second housing body constituting member  3120  has approximately the same structure as the first housing body constituting member  3110 , and has a base plate  3121  and a plurality of insertion portions  3122  (second link portions), positioning protrusions  3123  and a side wall portion  3124 . 
   The base plate  3121  has a nearly plate-like shape, and has a support surface  3121   a  which supports an end portion of the second printed board (second connection target)  1120  (see  FIG. 27 ). 
   The insertion portions  3122 , which are nearly columnar, are formed on the support surface  3121   a  of the base plate  3121 . The distal end of each insertion portion  3122  is formed into a nearly tapered shape. The insertion portions  3122  are aligned in two rows in a lengthwise direction L 2  of the second housing body constituting member  3120  at equal intervals. One row of the insertion portions  3122  is shifted from the other row of the insertion portions  3122  by a half pitch in the lengthwise direction L 2 . 
   The positioning protrusions  3123  are formed at both end portions of the support surface  3121   a  of the base plate  3121 . 
   The side wall portion  3124  is formed at the peripheral portion of the support surface  3121   a  of the base plate  3121 . 
   The contacts  3130  are formed by punching out a metal plate. The contact  3130  has a first contact portion  3131 , a second contact portion  3132 , a first spring portion  3133 , a second spring portion  3134 , a link portion  3135 , press-in portions  3136 ,  3137 , and press-in portions  3138 ,  3139  (see  FIG. 22 ). 
   The first contact portion  3131  is nearly triangular. The first contact portion  3131  contacts a through hole  1111  (see  FIG. 26 ) of the first printed board  1110 . 
   The second contact portion  3132  is nearly triangular. The second contact portion  3132  contacts a through hole  1121  (see  FIG. 26 ) of the second printed board  1120 . 
   One end of the first spring portion  3133  is coupled to the first contact portion  3131 , and the other end of the first spring portion  3133  is coupled to the link portion  3135 . The first spring portion  3133  presses the first contact portion  3131  against the through hole  1111 . 
   One end of the second spring portion  3134  is coupled to the second contact portion  3132 , and the other end of the second spring portion  3134  is coupled to the link portion  3135 . The second spring portion  3134  presses the second contact portion  3132  against the through hole  1121 . 
   The link portion  3135  extends to the second housing body constituting member  3120  from the first housing body constituting member  3110 , and has a curved portion (expanding portion)  3135   a  at a position slightly closer to the second spring portion  3134  than the intermediate position thereof. The link portion  3135  is placed over between the first housing body constituting member  3110  and the second housing body constituting member  3120  to couple the first housing body constituting member  3110  and the second housing body constituting member  3120  together. 
   The press-in portions  3136 ,  3137  are coupled to one end portion of the link portion  3135  in such a way as to sandwich the first spring portions  3131 ,  3131 . The press-in portions  3136 ,  3137  are pressed into the first housing body constituting member  3110 . 
   The press-in portions  3138 ,  3139  are coupled to the other end portion of the link portion  3135  in such a way as to sandwich the second spring portions  3134 ,  3134 . The press-in portions  3138 ,  3139  are pressed into the second housing body constituting member  3120 . 
   The contacts  3150  are formed by punching out a metal plate. The contact  3150  has the same shape and the same size as the contact  3130  to intend to share parts. It is to be noted that when the contacts  3130 ,  3150  are pressed into the first and second housing body constituting members  3110  and  3120 , it is necessary to set the top surface of the contact  3130  and the bottom surface of the contact  3150  facing in the same direction. The contact  3150  has a first contact portion  3151 , a second contact portion  3152 , a first spring portion  3153 , a second spring portion  3154 , a link portion  3155 , press-in portions  3156 ,  3157 , and press-in portions  3158 ,  3159  (see  FIG. 21 ). 
   As shown in  FIG. 21 , the first contact portion  3151  is nearly triangular. The first contact portion  3151  contacts the through hole  1111  (see  FIG. 26 ) of the first printed board  1110 . 
   The second contact portion  3152  is nearly triangular. The second contact portion  3152  contacts the through hole  1121  (see  FIG. 26 ) of the second printed board  1120 . 
   One end of the first spring portion  3153  is coupled to the first contact portion  3151 , and the other end of the first spring portion  3153  is coupled to the link portion  3155 . The first spring portion  3153  presses the first contact portion  3151  against the through hole  1111 . 
   One end of the second spring portion  3154  is coupled to the second contact portion  3152 , and the other end of the second spring portion  3152  is coupled to the link portion  3155 . The second spring portion  3154  presses the second contact portion  3152  against the through hole  1121 . 
   The link portion  3155  extends to the second housing body constituting member  3120  from the first housing body constituting member  3110 , and has a curved portion (expanding portion)  3155   a  at a position slightly closer to the first spring portion  3153  than the intermediate position thereof. The link portion  3155  is placed over between the first housing body constituting member  3110  and the second housing body constituting member  3120  to couple the first housing body constituting member  3110  and the second housing body constituting member  3120  together. 
   The press-in portions  3156 ,  3157  are coupled to one end portion of the link portion  3155  in such a way as to sandwich the first contact portions  3151 ,  3151 . The press-in portions  3156 ,  3157  are pressed into the first housing body constituting member  3110 . 
   The press-in portions  3158 ,  3159  are coupled to the other end portion of the link portion  3155  in such a way as to sandwich the second spring portions  3154 ,  3154 . The press-in portions  3158 ,  3159  are pressed into the second housing body constituting member  3120 . 
   The first housing body constituting member  3110  has a plurality of retaining spaces  3115 ,  3116  as shown in  FIG. 22 . 
   The retaining spaces  3115  are formed at the insertion portions  3112  and the base plate  3111 . The retaining spaces  3115  are aligned in the lengthwise direction L 1  of the first housing body constituting member  3110  at equal intervals. The first spring portions  3133 ,  3153  are retained in a deformable manner in spaces at the side of the base plate  3111  of the retaining spaces  3115 . The first contact portions  3131 ,  3151  are retained in a deformable manner in spaces at the side of the first insertion portion  3112  (retaining portions  3115   a ) of the retaining spaces  3115 . The first contact portions  3131 ,  3151  partially protrude outside the retaining portions  3115   a.    
   The retaining spaces  3116  are formed at the side wall portion  3114  and the base plate  3111 . The retaining spaces  3116  are aligned in the lengthwise direction L 1  of the first housing body constituting member  3110  at equal intervals. 
   The second housing body constituting member  3120  has a plurality of retaining spaces  3125 ,  3126  as shown in  FIG. 22 . 
   The retaining spaces  3125  are formed at the insertion portions  3122  and the base plate  3121 . The retaining spaces  3125  are aligned in the lengthwise direction L 2  of the second housing body constituting member  3120  at equal intervals. The second spring portions  3134 ,  3154  are retained in a deformable manner in spaces at the side of the base plate  3121  of the retaining spaces  3125 . The second contact portions  3132 ,  3152  are retained in a deformable manner in spaces at the side of the second insertion portion  3122  (retaining portions  3125   a ) of the retaining spaces  3125 . The second contact portions  3132 ,  3152  partially protrude outside the retaining portions  3125   a.    
   The retaining spaces  3126  are formed at the side wall portion  3124  and the base plate  3121 . The retaining spaces  3126  are aligned in the lengthwise direction L 2  of the second housing body constituting member  3120  at equal intervals. 
   The curved portions  3135   a ,  3155   a  are retained in the retaining spaces  3116 ,  3126  in a deformable manner. The sizes of the retaining spaces  3116 ,  3126  in the lengthwise directions L 1 , L 2  are larger than the sizes of the curved portions  3135   a ,  3155   a  in the lengthwise directions L 1 , L 2 . As a result, the curved portions  3135   a ,  3155   a  can absorb the deviations between the first housing body constituting member  3110  and the second housing body constituting member  3120  in the lengthwise directions L 1 , L 2 . 
   As shown in  FIGS. 26 and 27 , conductive passages  1112  are connected to the through holes  1111  of the first printed board  1110 . Positioning holes  1113  are formed on the first printed board  1110 . The positioning holes  1113  receive the positioning protrusions  3113 . 
   Conductive passages  1122  are connected to the through holes  1121  of the second printed board  1120 . Positioning holes  1123  are formed on the second printed board  1120 . The positioning holes  1123  receive the positioning protrusions  3123 . 
   To connect the first printed board  1110  and the second printed board  1120  together using connectors  301 , the relay connector  3101  should be fixed to the chassis  7  beforehand. 
   To fix the relay connector  3101  to the chassis, as shown in  FIGS. 23 and 24 , the relay connector  3101  should be positioned so that the hook  33  and projection  35  are positioned above the hole  72 , after which the relay connector  3101  is lowered to permit the hook  33  and projection  35  to be inserted into the hole  72 . 
   As a result, the claw  33   b  of the hook  33  is hooked at the peripheral portion of the hole  72  as shown in  FIG. 25 , so that the relay connector  3101  is fixed to the chassis  7 . 
   Next, as shown in  FIGS. 26 and 27 , the positioning holes  1123  of the second printed board  1120  are aligned with the positioning protrusions  3123  of the second housing body constituting member  3120 , and the second printed board  1120  is lowered so that both the positioning protrusions  3123  respectively pass through both positioning holes  1123 . Since the second printed board  1120  is positioned to the second housing body constituting member  3120  by the positioning holes  1123  and the positioning protrusions  3123 , all the insertion portions  3122  are inserted into all the through holes  1121 , allowing the second contact portions  3132 ,  3152  protruding from the retaining portions  3125   a  to contact the through holes  1121 , so that conduction of the contacts  3130 ,  3150  to the second printed board  1120  is established. 
   Likewise, the first printed board  1110  is also mounted on the first housing body constituting member  3110 , and the first printed board  1110  and the second printed board  1120  are electrically connected together by the connector  3101 , as shown in  FIG. 28 . 
   In a case where the second printed board  1120  is placed on the support surface  3121   a  of the second housing body constituting member  3120  to pass the positioning protrusions  3123  through the positioning holes  1123 , if the second printed board  1120  is slightly tilted to the support surface  3121   a , the second contact portions  3132 ,  3152  are inserted into the through holes  1121  relatively obliquely, thereby producing force which tends to deform the second contact portions  3132 ,  3152 , and the second spring portions  3134 ,  3154 . However, the force is mostly received at the insertion portions  3122 , so that the second contact portions  3132 ,  3152 , and the second spring portions  3134 ,  3154  do not deform. This is applied to a case where the first printed board  1110  is placed on the support surface of the first housing body constituting member  3110  to pass the positioning protrusions  3113  through the positioning holes  1113 . 
   Because the first contact portions  3131 ,  3151  are protected by the insertion portions  3112 , and the second contact portions  3132 ,  3152  are protected by the insertion portions  3122 , a material for the contacts  3130 ,  3150  for use need not have high strength, and a material with much flexibility can be used. This, as a result, can permit the first and second contact portions  3131 ,  3151 ,  3132 ,  3152  to be easily inserted into the through holes  1111 ,  1121 . 
   As described above, according to this embodiment, the similar functions and effects to those of the first and second embodiments can be achieved, and the contacts  3130 ,  3150  can be inserted into the through holes  1111 ,  1121  easily, making it possible to prevent the deformation of the contacts  3130 ,  3150 . 
   Because the positioning protrusions  3113 ,  3123  are provided, even if external force like tensile force is applied to the first and second printed boards  1110 ,  1120  after the first and second printed boards  1110 ,  1120  are mounted on the connector  3101 , the external force can be received by the positioning protrusions  3113 ,  3123 , making it possible to prevent the insertion portions  3112 ,  3122  or the like from being broken. 
   Although the projection  35  which restricts the elastic deformation of the hook  33  is provided in the above-described embodiments, the projection  35  may not be provided. 
   While the hook  33  is used as an engagement portion and the hole  72  is used as a to-be-engaged portion in the above-described embodiments, the engagement portion is not limited to the hook  33 , and the to-be-engaged portion is not limited to the hole  72 , either. 
   While the first and second printed boards  9 ,  9 ′,  1110 ,  1120  are mounted on the chassis  7  in above-described embodiments, the mount target of the first and second printed boards  9 ,  9 ′,  1110 ,  1120  is not limited to the chassis  7 , but there may be a case where the mount target thereof is a casing or the like, for example. 
   Although the first and second printed hoards  9 ,  9 ′,  1110 ,  1120  are connected by the relay connector  1 ,  201 ,  3101  in above-described embodiments, the present invention can also be adapted to connections, such as FFC (Flexible Flat Cable) and FPC (Flexible Printed Circuit). 
   The foregoing description has explained preferable embodiments of the present invention, and it should be apparent to those skilled in the art that the invention may be modified in various forms without departing from the spirit and scope of the invention.