Patent Publication Number: US-7214080-B2

Title: Connector and a connector assembly

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to a connector, to a connector assembly and to an assembling method therefor. 
   2. Description of the Related Art 
   Japanese Unexamined Patent Publication No. S63-257187 discloses a connector assembly with female and male connectors that are connectable with each other. The female connector has a terminal accommodating portion for holding female terminal fittings. An outer tube surrounds the terminal accommodating portion. A seal ring is mounted on the outer surface of the terminal accommodating portion at a position inside the outer tube. The male connector has a tubular receptacle and male terminal fittings with tabs that project into the receptacle. The surrounding wall of the receptacle is inserted into a clearance between the seal ring and the outer tube when the connectors are connected. As a result, the seal ring is squeezed in the thickness direction to provide sealing between the connectors. 
   The above-described connector assembly may be used in a high vibration environment, such as in an engine compartment of an automotive vehicle. Vibrations may cause the connectors to shake relative to each other. This shaking can cause the terminal fittings to abrade and can impair contact reliability between the terminal fittings. The seal ring fills the clearance between the connectors, but may not suppress the shaking sufficiently. 
   U.S. Pat. No. 5,336,540 discloses another connector assembly with female and male connectors that are connectable with each other. The female connector includes a housing and a resiliently deformable lock arm extends back on the housing. The male connector has a housing with an interlocking portion at a position corresponding to the lock arm. A lock projection of the lock arm engages the interlocking portion to hold the two housings in a properly connected condition. 
   The housing with the lock arm is likely to be formed from a resin that has lower hardness than resin of the housing with the interlocking portion. Vibration or heat generated after the housings are connected may cause the lock projection of the lock arm to deform due to creep of the resin resulting from the contact with the interlocking portion. Thus, a locking function may be reduced and may cause shaking between the housings. Shaking can impair the contact reliability between male and female terminal fittings in the housings. 
   The invention was developed in view of the above problem and an object thereof is to increase the lifetime and operability of the connector. 
   SUMMARY OF THE INVENTION 
   The invention relates to a connector that has an outer housing and an inner housing accommodated in the outer housing. The inner housing is adapted to hold at least one terminal fitting. A resilient member is sandwiched between portions of the inner and outer housings and supports the inner housing for floating movement in connecting directions of the connector with a mating connector. The inner housing can be pushed by the mating connector as the mating connector is fit in the outer housing and moves towards a portion of the outer housing. Accordingly, vibration-related abrasion of terminal fittings is suppressed to increase the life and operability of the connector. 
   The outer housing preferably is substantially tubular and has one end at least partly closed by a back wall. The back wall is the portion of the outer housing for sandwiching the resilient member. 
   The mating connector preferably can be locked in the outer housing. 
   At least one receiving portion preferably is on the inner surface of the outer housing, and at least one latch is on the outer surface of the inner housing. The latch contacts the receiving portion to mount the inner housing substantially rigidly in the outer housing before the mating connector is connected. Thus, the inner housing can be set correctly at a connection position with the mating connector while having the shaking restricted. However, the latch and the receiving portion are separated from each other by a movement of the inner housing during connection with the mating connector. Thus, the substantially rigidly mounted state of the inner housing is canceled, and the inner housing is supported for loose floating movement. 
   One of the latch and the receiving portion preferably includes a loose movement preventing portion for surrounding the other of the latch and the receiving portion before the mating connector is connected. The loose movement preventing portion prevents the inner housing from loosely moving at an angle to the connecting direction. The loose movement preventing portion slides on the outer surface of the other of the latch and the receiving portion during connection with the mating connector. Accordingly, the inner housing moves to a loose movement permitting space that permits loose movements of the inner housing after the mating connector is connected. As a result, the inner housing and the mating connector are held coaxially, and the inner housing can smoothly follow the movement of the mating connector. 
   At least three supports preferably are arranged at substantially even intervals around the periphery of the resilient member and resiliently press the pressable surface of the inner housing towards the mating connector. Thus, the resilient forces of the supports are dispersed evenly over substantially the entire periphery of the inner housing to prevent displacement of the inner housing from the central axis of the mating connector. 
   The mating connector preferably has a receptacle with a surrounding wall that is insertable into a space between the inner surface of the outer housing and the outer surface of the inner housing. A flange bulges out at a position on the outer surface of the inner housing to face the leading end of the surrounding wall of the receptacle in the connecting direction. A seal is mounted adjacent the flange and is squeezed between the outer surface of the inner housing and the inner surface of the surrounding wall of the receptacle after the mating connector is connected. A deformation preventing portion is provided at a bulging end of the flange and faces the seal for pressing the surrounding wall of the receptacle from an outer side after the mating connector is connected to prevent a widening deformation thereof. Thus, shaking of the receptacle can be suppressed after the mating connector is connected and the sealing ability of the seal remains good. 
   One of the mating connector and the outer housing preferably has a resiliently deformable lock arm, and the other has an interlocking portion. Engagement of the lock arm with the interlocking portion holds the mating connector in the outer housing. Corresponding parts of the outer housing and the mating connector both are made of synthetic resins. However, the resin for the interlocking portion is harder than the resin for the lock arm. Thus, there is a possibility that the force of the resilient member will deform a surface of the lock arm that contacts the interlocking portion due to creep of the resin. Accordingly, a locking function could be reduced and shaking could occur between the housings. A reinforcing plate covers at least part of a surface of the lock arm that contacts the interlocking portion to prevent creep of the resin. 
   One of the mating connector and the outer housing preferably has at least one lifting portion that is displaceable as the lock arm is moved, and the other thereof includes at least one interacting portion at a position adjacent the interlocking portion. The lifting portion moves onto the interacting portion to lift the lock arm during the connection of the mating connector so that the lock arm and the interlocking portion do not interfere with each other. Thus, the interlocking portion is not abraded by the reinforcing plate of the lock arm, and a satisfactory locking function is maintained. 
   The lock arm preferably is on the outer housing, the resilient member preferably is a metallic leaf spring, and the reinforcing plate is formed by extending a part of the leaf spring along a surface of the lock arm. The extension of the reinforcing plate from the resilient member reduces the number of parts. Further, disposition of the reinforcing plate along the inner surface of the lock arm reinforces the lock arm over a wide range. 
   The invention also relates to a connector assembly comprising at least one pair of male and female connectors as described above. 
   These and other objects and advantages of the invention will become more apparent upon reading the following detailed description and accompanying drawings. Even though embodiments are described separately, single features may be combined to additional embodiments. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded perspective view of male and female connectors according to a first embodiment. 
       FIG. 2  is a front view of an outer housing. 
       FIG. 3  is a rear view of the outer housing. 
       FIG. 4  is a front view of an inner housing. 
       FIG. 5  is a rear view of the inner housing. 
       FIG. 6  is a front view of the male connector. 
       FIG. 7  is a side view in section of the inner housing and parts to be assembled with the inner housing. 
       FIG. 8  is a side view in section of the outer housing. 
       FIG. 9  is a horizontal section of the outer housing. 
       FIG. 10  is a side view of a spring member. 
       FIG. 11  is a side sectional view of the connectors before connection. 
       FIG. 12  is a side sectional view of the connectors being connected. 
       FIG. 13  is a side sectional view of the connected connectors. 
       FIG. 14  is a horizontal section of the female connector. 
       FIG. 15  is a horizontal section of the properly connected connectors. 
       FIG. 16  is a side view in section of the female connector showing a state where latching portions and receiving portions are engaged. 
       FIG. 17  is a side view in section of the female connector showing a state where the latching portions and the receiving portions are separated. 
       FIG. 18  is a side view in section of the female connector showing a state where the inner housing and the like are assembled. 
       FIG. 19  is an exploded perspective view of male and female connectors according to a second embodiment. 
       FIG. 20  is a front view of an outer housing. 
       FIG. 21  is a front view of the male connector. 
       FIG. 22  is a side view in section of an outer housing. 
       FIG. 23  is a side view of a spring member. 
       FIG. 24A  is a side view in section of the two connectors when a lock arm is lifted up during a connecting operation. 
       FIG. 24B  is a side view in section of the two connectors when lifting portions move onto interacting portions during the connecting operation. 
       FIG. 25A  is a side sectional view of the connectors when the lock arm moves over an interlocking portion at a final stage of the connection. 
       FIG. 25B  is a side sectional view of two connectors when the lifting portions move over the interacting portions at the final stage of connection. 
       FIG. 26A  is a side view of the two connectors properly connected to engage the lock arm and the interlocking portion. 
       FIG. 26B  is a side view in section of the two connectors properly connected to engage the lifting portions and the interacting portions. 
       FIG. 27  is a side view in section showing a state where the lock arm is lifted to such a position as not to interfere with the interlocking portion. 
       FIG. 28  is a horizontal section of the outer housing. 
       FIG. 29  is a horizontal section of the connectors properly connected. 
       FIG. 30  is a rear view of the outer housing. 
       FIG. 31  is a front view of the inner housing. 
       FIG. 32  is a rear view of the inner housing. 
       FIG. 33  is a side view in section of the inner housing and parts to be assembled with the inner housing. 
       FIG. 34A  is a side view in section of the two connectors before being connected showing the lock arm and the interlocking portion. 
       FIG. 34B  is a side view in section of the two connectors before being connected showing lifting portions and interacting portions. 
       FIG. 35  is a horizontal section of the female connector. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A connector assembly according to a first embodiment of the invention includes female and male connectors F and M that are connectable with one another as shown in  FIGS. 1 to 18 . In the following description, ends of the connectors F, M that are connected are referred to as front ends and reference is made to  FIGS. 1 and 2  concerning the vertical direction. 
   The male connector M is made e.g. of a synthetic resin, and is to be mounted directly on a wall of an unillustrated apparatus, such as a junction box, an instrument panel, a housing of an electric appliance, etc. The male connector M includes straight male terminal fittings  90 . A terminal holding portion  92  extends substantially normal to forward and backward directions FBD and the male terminal fittings  90  are inserted through and held in the terminal holding portion  92 . A rectangular tubular receptacle  93  projects forward from the peripheral edge of the terminal holding portion  92 , and a substantially rectangular tube  94  projects back from the peripheral edge of the terminal holding portion  92 . Front ends of the male terminal fittings  90  project into the receptacle  93 , rear ends thereof project into the rectangular tube  94 , and intermediate parts thereof penetrate the terminal holding portion  92 . 
   The leading end of the surrounding wall of the receptacle  93  has an outer surface that is cut to be a thin pushing portion  95 . Eight elongated guide ribs  96  extend in substantially forward and backward direction FBD on the surrounding wall of the receptacle  93  and are spaced from one another around the periphery of the surrounding wall of the receptacle  93 . Rear ends of the guide ribs  96  are substantially at the rear end of the receptacle  93 , while the front ends of the guide ribs  96  are behind the front end of the receptacle  93 . An interlocking portion  97  projects on the upper surface of the surrounding wall of the receptacle  93  and a slanted guiding surface  97 A slopes up and back on the front of the interlocking portion  97 . A substantially vertical locking surface  97 B is formed on the rear of the interlocking portion  97 . Two guide ribs  96  are arranged on the upper surface of the surrounding wall of the receptacle  93  at opposite sides of the interlocking portion  97 . The front ends of the guide ribs  96  are behind the front end of the receptacle  93 . 
   The female connector F has a rectangular tubular outer housing  10  and a substantially rectangular block-shaped inner housing  30 , each of which is made e.g. of a synthetic resin. The inner housing  30  is adapted to hold female terminal fittings  80  connected with ends of wires W and is disposed within the outer housing  10  so that a forwardly open connection space Q is defined between the outer and inner housings  10  and  30 . The female connector F also has a spring  50  disposed between rear ends of the inner and outer housings  30  and  10 . Further, a retainer  31 , a seal  32  and a front member  33  are assembled with the inner housing  30 , as shown in  FIG. 1 . 
   The inner housing  30  has a main portion  35  with two side-by-side terminal accommodating chambers  34  as shown in  FIGS. 4 and 5 . A flange  36  bulges out from the outer peripheral surface of the rear end of the main portion  35  and extends over the entire periphery. A terminal inserting portion  37  projects back from the rear end of the main portion  35  and communicates with the terminal accommodating chambers  34 . The terminal inserting portion  37  has two round tubes  37 A that extend in forward and backward directions FBD. The walls of the tubes  37 A are joined in forward and backward directions FBD. 
   As shown in  FIG. 7 , a lock  38  is cantilevered forward from the upper wall of each terminal accommodating chamber  34  of the main portion  35 . The locks  38  are resiliently deformable up and down in directions intersecting an insertion direction of the terminal fittings  80  into the female connector F. The left lock  38  (when viewed from front) is exposed, whereas the right lock  38  (when viewed from front) is covered by a cover  39  above a deformation space therefor. The cover  39  is in the form of an eave with a base end connected with the rear end of the main portion  35 . An upper front-member locking groove  41  extends in the width direction WD on the upper surface of the cover  39  for locking the front member  33 . Similarly, a lower front-member locking groove  41  is formed in the bottom surface of the main portion  35  substantially facing the cover  39 . A mount hole  42  opens in opposite side surfaces of the main portion  35 . The mount hole  42  penetrates the terminal accommodating chambers  34  in the width direction WD under the cover  39 . The mount hole  42  also opens in the lateral upper surface of the main portion  35  at one side of the cover  39 . 
   The retainer  31  is a side-type retainer made e.g. of a synthetic resin. The retainer  31  includes a flat plat-shaped operable portion  43  that can close the opening at one end of the mounting hole  42 . A comb-shaped terminal locking section  44  projects from a plane surface of the operable portion  43 . The retainer  31  is movable between a partial locking position where the retainer  31  is inserted into the mount hole  42  of the main portion  35  to permit the insertion and withdrawal of the female terminal fittings  80  and a full locking position where the terminal locking section  44  locks the female terminal fittings  80 . 
   The front member  33  is made e.g. of a synthetic resin and has a cap-shape. The front member  33  includes a front wall  45  for covering the front end of the main portion  35 , and a surrounding wall  46  that projects back from the periphery of the front wall  45  to cover the sides of the main portion  35 . The front wall  45  has terminal insertion openings  45 A at positions corresponding to the terminal accommodating chambers  34 . The male terminal fittings  90  can be inserted into the terminal insertion holes  45 A from the front and guided into the terminal accommodating chambers  34 . Retaining projections  47  are provided on inner surfaces of the upper and lower walls of the surrounding wall  46 , and engage the corresponding front-member locking grooves  41 . Specifically, the retaining projections  47  fit resiliently in the front-member locking grooves  41  as the front member  33  is mounted to a proper depth on the main portion  35 . Thus, the front member  33  is locked on the inner housing  30 . 
   A rear end portion of the surrounding wall  46  is recessed to form an insertion opening  46 A that can communicate with the mount hole  42 . Thus, the retainer  31  can be inserted and withdrawn through the insertion opening  46 A. A jig inserting portion  48  is formed on the surrounding wall  46  and inclines in toward the insertion opening  46 A. The retainer  31  can be displaced from the full locking position by inserting an unillustrated jig along a sloped surface of the jig inserting portion  48 . Protrusions  49  are spaced from one another around the periphery of the surrounding wall  46 . The protrusions  49  engage the inner surface of the receptacle  93  of the male connector M to prevent shaking relative to the male connector M. 
   The seal  32  is ring-shaped and is made of a resilient material, such as rubber. The seal  32  is mounted on the outer peripheral surface of the rear end of the main portion  35  at a position immediately before the flange  36 . An introducing hole  32 A extends through the middle of the seal for receiving the main portion  35 . A middle part of the seal  32  with respect to forward and backward directions FBD bulges out transverse to the forward and backward directions FBD while the front and rear ends of the seal  32  are thinned on the outer surface. The thinned front end of the seal  32  can fit into a recess  71  at the front edge of the surrounding wall  46  of the front member  33 , and the thinned rear end of the seal  32  can fit into a groove  72  in the front surface of the flange  36 . In this way, the seal  32  is prevented from moving from the outer surface of the inner housing  30 . 
   The groove  72  is formed over the entire periphery at the base end of the front surface of the flange  36  substantially continuous with the main portion  35 . Further, a deformation preventing portion  73  projects forward at the bulging end of the flange  36 , and a recess  74  is formed inside the deformation preventing portion  73  for receiving the pushing portion  95  of the receptacle  93  of the male connector M. The seal  32  is squeezed resiliently between the surrounding wall of the receptacle  93  and the main portion  35  to provide hermetic sealing. A force could act on the pushing portion  95  of the receptacle  93  to widen the opening of the pushing portion  95  due to the resilient force of the seal  32 . However, the deformation preventing portion  73  presses the pushing portion  95  from an outer side to hinder widening of the pushing portion  95 . As shown in  FIG. 4 , biting projections  75  are spaced apart around the inner periphery of the deformation preventing portion  73 . The biting projections  75  bite in the outer surface of the pushing portion  95  of the receptacle  93  to hold the receptacle  93  transversely. 
   Two recessed grooves  76  are formed in the upper part of the bulging end surface of the flange  36  and are spaced apart in the width direction WD, whereas two guide ribs  77  are formed on the bottom part of the bulging end surface of the flange  36  and are spaced part in the width direction WD. Two latches  78  project from the opposite lateral parts of the bulging end surface of the flange  36 . As shown in  FIG. 14 , each latch  78  is engageable with a corresponding receiving portion  29  in the outer housing  10 . The front surface of each latch  78  is a substantially vertical locking surface  78 A and the rear surface thereof is a guiding surface  78 B that slopes up towards the front. 
   The spring  50  is a leaf spring formed by bending a metal plate that has been punched out into a specified shape. A through hole  51  extends through central part of a substantially rectangular flat portion  52  of the spring  50 , as shown in  FIGS. 1 and 10 , and is dimensioned to loosely receive the terminal inserting portion  37  of the inner housing  30 . Four strip-shaped supports  53  extend from the corners of the flat portion  52  and are folded back along corresponding side edges at the front surface of the flat portion  52 . The supports  53  are arranged at substantially even intervals of about 90° about the periphery of the flat portion  52 , and are bent up towards their free end. Pressing portions  54  are angled from the free ends of the bent supports  53  and utilize reaction forces of the spring  50  to press a smooth flat pressable surface  36 A that extends vertically on the rear of the flange  36 . Positioning projections  55  are bent back from the opposite side edges of the flat portion  52 . 
   The outer housing  10  has a back wall  12  and an outer tube  13  that projects forward from the periphery of the back wall  12 , as shown in  FIGS. 2 ,  3  and  8 . The spring  50  and the inner housing  30  are inserted in this order into the outer housing  10 . Thus, the spring  50  contacts the back wall  12  and the inner housing  30  is supported resiliently on the spring  50 . A guiding tube  14  projects forward from the front surface of the back wall  12  at a position corresponding to the through hole  51  of the spring  50 . The guiding tube  14  is formed with a loose insertion hole  14 A so that the terminal inserting portion  37  of the inner housing  30  can be inserted loosely through the back wall  12 . The terminal inserting portion  37  can be inserted through the through hole  51  of the spring  50  and then loosely into the loose insertion hole  14 A for movement in forward and backward directions FBD in the loose insertion hole  14 A. Hooking holes  15  are formed in the back wall  12  at opposite sides of the loose insertion hole  14 A and receive the positioning projections  55  of the spring  50 . 
   A lock arm  16  is provided at the upper wall of the outer tube  13  and is engageable with the interlocking portion  97  of the male connector M. The lock arm  16  is accommodated in an arm accommodating space  17  that opens in the upper wall of the outer tube  13  and the back wall  12 . More specifically, the lock arm  16  is supported on the opposite side edges of the arm accommodating chamber  17  by two couplings  18 , and is resiliently deformable up and down with both couplings  18  as supports, as shown in  FIG. 9 . A wide arm operating portion  19  is provided at the rear end of the lock arm  16  and can be operated to disengage the lock arm  16  from the interlocking position  97 . Two bulges  21  are formed on the outer tube  13  and project into the arm accommodating space  17 . The bulges  21  cover opposite sides of the arm operating portion  19  from above so that the lock arm  16  cannot be caught by a wire W or the like and rolled up. A lock head  22  is provided at the front end of the lock arm  16  and has an outer surface that slopes down and in toward the front in its natural state. A substantially rectangular locking hole  23  penetrates the lock head  22 . An engageable surface  23 A is formed at the front of the lock hole  23  and slopes up and out towards the front for strongly engaging the base end of the locking surface  97 B of the interlocking portion  97 . A groove  24  is formed in an area of the lower surface of the lock arm  16  behind the locking hole  23 . The groove  24  extends in forward and backward directions FBD and makes an opening in the rear surface. 
   A bridge  25  is provided at the upper wall of the outer tube  13  and crosses a front area of the arm accommodating space  17  in the width direction WD. The front end of the lock head  22  is below the bridge  25  and can be seen through an insertion space Z of the outer tube  13  when viewed from front. 
   Two resistance arms  11  are provided below the opposite lateral edges of the accommodating chamber  17  in the outer tube  13  and extend back from the front end of the outer tube  13 . The resistance arms  11  are substantially parallel to and spaced slightly from the upper wall of the outer tube  13  and are resiliently deformable in the width direction WD. Contacts  11 A are provided at the leading ends of the resistance arms  11  and face the arm accommodating space  17 . The front ends of the guide ribs  96  on the upper surface of the surrounding wall of the receptacle  93  engage the contacts  11 A and deform the resistance arms  11  out against their own resilient forces. A large connecting force is required to resiliently deform the resistance arms  11 . The connecting operation then proceeds at a stroke by the action of an inertial locking mechanism for creating a large connection resistance, thereby avoiding a situation where the two connectors F, M are left partly connected. 
   Guide grooves  26  extend in forward and backward directions FBD on the outer tube  13  at positions corresponding to the guide ribs  96  on the receptacle  93  of the male connector M, and at positions corresponding to the guide ribs  77  and the latches  78  on the flange  36  of the inner housing  30 . The guide ribs  96 ,  77  and the latches  78  can be inserted in and guided along the guide grooves  26 . The guide grooves  26  that correspond to the two guide ribs  96  on the upper surface of the surrounding wall of the receptacle  93  are formed by the insertion space Z between the inner side surfaces of the resistance arms  11 , and both guide ribs  96  and the interlocking portion  97  are insertable into the insertion space Z. 
   The guide grooves  26  that correspond to the lower guide ribs  96  on the opposite side surfaces of the surrounding wall of the receptacle  93  and the latches  78  on the flange  36  of the inner housing  30  are referred to herein as main guide grooves  26 A and communicate with the hooking holes  15  in the back wall  12 . A main receiving portion  27  projects in at an intermediate position of each main groove  26 A with respect to forward and backward directions FBD so that the main receiving portions  29  face each other in the width direction WD. A guidable surface  27 A slopes in and back on the front of each main receiving portion  27  and can be held substantially in sliding contact with the guiding surface  78 B of the corresponding latch  78 . An interlocking surface  27 B extends normal to the forward and backward directions FBD at the rear of each main receiving portion  27  and can be brought into surface contact with the locking surface  78 A of the latch  78 . The projecting height of the main receiving portions  27  is shorter than the depth of the main guide grooves  26 A, and a vertical dimension of the main receiving portions  27  is less than the vertical dimension of the bottom surfaces of the main guide grooves  26 A. 
   A loose movement preventing portion  28  is formed in each main guide groove  26 A at a position behind the respective main receiving portion  27 . Each loose movement preventing portion  28  is a substantially U-shape protrusion formed on the surfaces of the main groove  26   a  in a position to substantially surround three sides of the rear end of the main receiving portion  27 . The loose movement preventing portion  28  extends over substantially the entire height and width of the main guide groove  26 A. Thus, the loose movement preventing portion  28  narrows the groove width. The main receiving portion  27  and the loose movement preventing portion  28  in each main guide groove  26 A define a receiving portion  29 . The latch  78  that engages the main receiving portion  27  is fit closely into the loose movement preventing portion  28 . Thus, loose movements of the latch  78  are prevented with respect to the height direction and the width direction WD. More specifically, the length of the loose movement preventing portion  28  from the rear end of the main receiving portion  27  in forward and backward directions FBD is less than a moving amount of the inner housing  30  that moves as the two connectors F, M are connected. The latches  78  disengage from the loose movement preventing portions  28  when the two connectors F, M are connected properly to cancel the loose movement prevented state. 
   Slits  57  are formed in the outer tube  13  above and below each main guide groove  26 A. The slits  57  extend in forward and backward directions FBD and making openings in the back wall  12 . A resilient piece  58  that includes the main guide groove  26 A is formed between each pair of upper and lower slits  57 , and is resiliently deformable along the width direction WD with the front end of the outer tube  13  as a base. The resilient pieces  58  deform to widen the spacing therebetween when the latches  78  reach the guidable surfaces  27 A of the main receiving portions  27 , thereby permitting the latches  78  to move over the main receiving portions  27 . The resilient pieces  58  restore resiliently when the connectors F, M are connected properly so that the locking surfaces  78 A of the latches  78  and the interlocking surfaces  27 B of the main receiving portions  27  face each other in disengaging directions. As a result, the latches  78  are engaged with the receiving portions  29 . 
   The female connector F is assembled by mounting the seal  32  and the front member on the main portion  35  of the inner housing  30  from the front. The retainer  31  also is inserted sideways into the mount hole  42  of the main portion  35  to be held at the partial locking position. The female terminal fittings  80  crimped into connection with the ends of the wire W then are passed successively through the loose insertion hole  14 A of the outer housing  10  and the through hole  51  of the spring  50  and further are inserted into the terminal accommodating chamber  34  of the inner housing  30  from behind. A resilient or rubber plug  89  on the end of each wire W is brought into close sealing contact with the inner circumferential surface of the terminal accommodating chamber  34 . The retainer  31  then is pushed to the full locking position so that the female terminal fittings  80  are locked doubly by the locks  38  and the retainer  31 . 
   The spring  50  is inserted into the outer housing  10  from the front. Thus, the guiding tube  14  on the back wall  12  passes through the through hole  51  of the spring  50 , and the positioning projections  55  of the spring member  50  enter the hooking holes  15  of the back wall  12  and are hooked. Thus, the spring  50  is held in contact with the back wall  12  of the outer housing  10 . The inner housing  30  then is inserted from the front to bring the pressable surface  36 A of the inner housing  30  resiliently into contact with the pressing portions  54  of the supports  53  of the spring  50 . Upon inserting the inner housing  30 , the latches  78  of the flange  36  enter the main guide grooves  26 A of the outer housing  10  from the front and the inner housing  30  is pushed farther to the back so that the latches  78  move resiliently over the main receiving portions  27 . 
   The latches  78  are locked by the main receiving portions  27  when the inner housing  30  reaches a proper insertion position. The latches  78  are surrounded by the loose movement preventing portions  28 , as shown in  FIGS. 14 and 16 , to have loose movements prevented. Further, the supports  53  of the spring  50  are compressed resiliently a small amount between the pressable surface  36 A of the inner housing  30  and the front surface of the back wall  12 . The rear end of the terminal inserting portion  37  is substantially flush with the rear surface of the back wall  12  of the outer housing  10  when the inner housing  30  reaches the proper insertion position, and the front end of the front member  33  projects slightly more forward than the front opening of the outer housing  10 . 
   The male connector M is fit from the front into the outer housing  10  after the components of the female connector F are assembled. Thus, the guide ribs  96  of the receptacle  93  enter the corresponding guide grooves  26  of the outer housing  10 . The surrounding wall of the receptacle  93  is inserted into the connection space Q of the outer housing  10 , and the receptacle  93  is pushed to the back. The pushing portion  95  of the receptacle  93  then enters the recess  74  at the inner side of the deformation preventing portion  73  and is pushed against the front surface of the flange  36 . The flange  36  is pushed back by the pushing portion  95  as the male connector M is fit further. As a result the latches  78  are separated from the main receiving portions  27 . 
   The latches  78  slide on the loose movement preventing portions  28  as the male connector M is fit farther in, and the inner housing  30  is moved and guided along the same axis. The latches  78  separate from the loose movement preventing portions  28  when the two connectors F, M are connected properly and push the inner housing  30  to a loose movement permitting space defined at the rear of the outer housing  10 , as shown in  FIGS. 15 and 17 . 
   The lock arm  16  of the outer housing  10  moves resiliently onto the guiding surface  97 A of the interlocking portion  97  when the pushing portion  95  of the receptacle  93  is pushed against the front surface of the flange  36 , as shown in  FIG. 12 . The lock arm  16  engages the interlocking portion  97  when the connectors F, M reach the properly connected position shown in  FIG. 13 , thereby holding the connectors F, M together. The inner housing  30  is pushed to the loose movement permitting space, as described above, when the two connectors F, M are connected properly, and is supported floatingly between the back wall  12  of the outer housing  10  and the male connector M via the spring  50  for movement in connecting directions CD. The supports  53  of the spring  50  are compressed resiliently and press the pressable surface  36 A of the inner housing  30 . The surrounding wall of the receptacle  93  is squeezed in the thickness direction between the deformation preventing portion  73  of the flange  36  and the outer peripheral surface of the seal  32 , and is held strongly on the inner housing  30  by the biting projections  75  of the deformation preventing portion  73  and the protrusions  49  of the front member  33 . In this way, the male connector M and the inner housing  30  act as an integral unit. 
   The male connector M is coupled directly to the apparatus and hence vibrates if the apparatus vibrates. However, the spring  50  supports the inner housing  30  floatingly between the male connector M and the outer housing  10 . Therefore, the inner housing  30  displaces while following the movement of the male connector M, and there is substantially no likelihood of shaking between the inner housing  30  and the male connector M. Accordingly, the vibration timings of the male terminal fittings  90  in the male connector M and the female terminal fittings  80  in the inner housing  30  are synchronized, and the vibration will not abrade the female and male terminal fittings  80 ,  90 . 
   As described above, the inner housing  30  is supported floatingly to follow the movements of the male connector M, thereby suppressing vibration related abrasion of the terminal fittings  80 ,  90 . Therefore, contact reliability between the terminal fittings  80  and  90  can be ensured. 
   The loose movement preventing portions  28  prevent loose movements of the latches  78  of the inner housing  30  so that the latches  78  rigidly engage the interlocking portions  29  of the outer housing  10  before the connection with the male connector M. Thus, the inner housing  30  cannot shake prior to connection and the connection position with the male connector M can be determined precisely. The latches  78  and the loose movement preventing portions  28  slide on each other to guide the movement of the inner housing  30  during connection with the male connector M. Thus, the inner housing  30  and the male connector M are held substantially coaxial. The latches  78  separate from the loose movement preventing portions  28  of the receiving portions  29  and are freed from the rigidly engaged state when the male connector M is connected properly, and the inner housing  30  is moved to the loose movement permitting space in the outer housing  10 . Thus, the inner housing  30  will smoothly follow the movements of the male connector M. 
   The spring  50  has the four equally spaced supports  53  at substantially even intervals (90°). The supports  53  resiliently support and press the pressable surface  36 A of the inner housing  30  towards the male connector M. Thus, the resilient forces of the supporting portions  53  substantially equally act over the entire periphery of the inner housing  30 , thereby preventing a displacement of the central axis of the inner housing  30 . 
   The deformation preventing portion  73  presses the surrounding wall of the receptacle  93  to prevent the resilient force of the seal  32  from causing a widening deformation. Thus, vibrations will not shake the receptacle  93  after the connection of the two connectors F, M. As a result, the sealing property of the seal  32  will not be reduced. 
   A second embodiment of the invention is illustrated in  FIGS. 19 to 35 . The second embodiment differs from the first embodiment in the locking construction for the female and male connectors F, M. However, the inner housing  30 , the retainer  31 , the seal  32  and the front member  33  have substantially the same constructions as those of the first embodiment and are not described again. 
   The outer housing  10  is made e.g. of a polybutylene terephthalate resin (PBT), and preferably has no reinforcing material, such as glass fibers, to ensure good deflectability of the lock arm  16 . On the other hand, the receptacle  93  of the male connector M preferably contains a reinforcing material, such as glass fibers, and therefore is harder than the outer housing  10 . Accordingly, resilient forces of the spring  50  in a separating direction of the connectors F, M may cause the lock arm  16  to deform due to creep of the resin. Thus, a reinforcing plate  101  is inserted in the lock arm  16  to cover at least part of a surface that contacts the interlocking portion  97  for preventing resin creep. 
   The reinforcing plate  101  is formed unitarily with the spring  50  and includes a base  102  that extends from a substantially middle part of the upper edge of the substantially flat portion  52  to be arranged along the front surface of the back wall  12  of the outer housing  10 . An extension  103  extends forward from the upper end of the base  102  and is arranged along the inner surface of the lock arm  16 , as shown in  FIGS. 23 and 24A . A groove  24  is formed in the lower surface of the lock arm  16  and extends substantially in forward and backward directions FBD. The groove  24  opens in both front and rear surfaces of the lock arm  16  as shown in  FIGS. 20 and 22 , and the front part of the extension  103  is formed with a substantially rectangular window  104  that communicates with the locking hole  23  of the lock arm  16 . The extension  103  of the reinforcing plate  101  is fit in the groove  24 . 
   The female connector F of the second embodiment also has protecting means for preventing the interlocking portion  97  from being abraded by the metallic reinforcing plate  101  sliding on the interlocking portion  97  in the process of connecting the two connectors F, M. Specifically, widened portions  105  extend laterally out in the width direction WD from the opposite lateral edges of the lock arm  16  and lifting portions  106  are provided at the widened portions  105 , as shown in  FIG. 28 . The lifting portions  106  lift the lock arm  16  to avoid interference with the interlocking portion  97  in the process of connecting the two connectors F, M. Two interacting portions  107  project from the upper surface of the receptacle  93  of the mating male connectors M at the opposite sides of the interlocking portion  97 , as shown in  FIG. 21 , for engaging the lifting portions  106 . 
   An upwardly and rearwardly sloped guiding surface  107 A is formed at the front surface of each interacting portion  107 , and the front end thereof substantially aligns with the front end of the guiding surface  97 A of the interlocking portion  97 . Further, outer sides of the lifting portions  107  are connected unitarily with the guide ribs  96 . The upper ends of the interacting portions  107  are lower than the upper ends of the guide ribs  96  and the interlocking portion  97 . Lifting-portion guiding grooves  108  are formed in the upper surface of the receptacle  93  before and adjacent to the interacting portions  107  and extend up to the front surface of the receptacle  93 . 
   The lifting portions  106  project down and in at the front ends of the widened portions  105 . The widened portions  105  are thinned in areas behind the lifting portions  106  and are thinner than the lock arm  16 . The front surfaces of the lifting portions  106  slope down and in towards the back and can slide smoothly in contact with the guiding surfaces  107 A of the interacting portions  107 . The rear ends of the lifting portions  106  align with the front end of the locking hole  23 . The lifting portions  106  move along the lifting-portion guiding grooves  108  to move smoothly onto the guiding surfaces  107 A of the interacting portions  107 . 
   The second embodiment is similar to the first embodiment in that the inner housing  30  is supported floatingly between the male connector M and the outer housing  10  via the spring  50 . Thus, this structure is not described. A locking action by the lock arm  16  is described in detail below. 
   The connecting operation of the female and male connectors F, M starts by positioning the two connectors F, M in opposed relationship so that the connecting surfaces thereof face each other. The lifting portions  106  move onto the guiding surfaces  107 A of the interacting portions  107  after a while following the start of the connecting portion and lift the lock arm  106 , as shown in  FIG. 24B . The lock arm  16  has reached a position corresponding to the interlocking portion  97  in the state shown in  FIG. 24A , but is above the guiding surface  97 A of the interlocking portion  97  and hence does not contact the interlocking portion  97 . The lifting portions  106  reach positions where move over the interacting portions  107  as the connecting operation proceeds, as shown in  FIG. 24B . The lock arm  16  also reaches a position where it can move over the interlocking portion  97  as shown in  FIGS. 24A and 27 , but does not interfere with the interlocking portion  97 . 
   The components of the female connector F are assembled as described above with reference to the first embodiment. The male connector M then is inserted into the outer housing  10  from the front. As a result, the guide ribs  96  of the receptacle  93  fit into the corresponding guide grooves  26  of the outer housing  10 , while the surrounding wall of the receptacle  93  is inserted into the connection space Q of the outer housing  10 . The receptacle  93  is pushed to the back in this state. Thus, the pushing portion  95  of the receptacle  93  enters the recess  74  the inner side of the deformation preventing portion  73  and is pushed against the front surface of the flange  36 . The flange  36  is pushed by the pushing portion  95  and is moved back as the male connector M is inserted further (see  FIG. 29 ). As a result the latches  78  are separated from the main receiving portions  27 . Moreover, the inner housing  30  is pushed to a loose movement permitting space at the rear of the outer housing  10 . 
   The lifting portions  106  move onto the guiding surfaces  107 A of the interacting portions  107  before the lock arm  16  does and substantially when the pushing portion  95  of the receptacle  93  is pushed against the front surface of the flange  36 , as shown in  FIG. 24B . The lock arm  16  is unitary to the lifting portions  106  and is lifted as the lifting portions  106  move onto the guiding surfaces  107 A. The lock arm  16  has reached a position corresponding to the interlocking portion  97  in the state as shown in  FIG. 24A . However, the lock arm  16  is above the guiding surface  97 A of the interlocking portion  97  and does not contact with the interlocking portion  97 . When the connecting operation proceeds and the lifting portions  106  reach positions where they can move over the interacting portions  107 , as shown in  FIG. 25B , the lock arm  16  also reaches a position where it can move over the interlocking portion  97  as shown in  FIGS. 25A and 27 , but does not interfere with the interlocking portion  97 . 
   The lifting portions  106  move over the interacting portions  107  when the two connectors F, M are connected properly and the lock arm  16  is restored resiliently together with the widened portions  105 . Thus, the lock arm  16  and the interlocking portion  97  are engaged in separating directions of the two connectors F, M. The lifting portions  106  and the interacting portions  107  also are engaged with each other in separating directions of the two connectors F, M, as shown in  FIGS. 26A and 26B . As a result, the two connectors F, M are held together. The reinforcing plate  101  on the lock arm  16  does not contact the locking surface  97 B of the interlocking portion  97  until the two connectors F, M are connected properly. The latches  78  are separated from the receiving portions  29  (not including the loose movement preventing portions  28 ) and the inner housing  30  enters the loose movement permitting space, as shown in  FIG. 29  when the two connectors F, M are connected properly. 
   According to the second embodiment, the metallic reinforcing plate  101  is mounted to the lock arm  16  to prevent creep of the resin of the lock arm  16  after the two connectors F, M are connected. 
   The lifting portions  106  move onto the interacting portions  107  in the process of connecting the two connectors F, M and lift the lock arm  16  to a position to avoid interference with the interlocking portion  97 . Thus, the interlocking portion  97  is not abraded by the reinforcing plate  101  and a good locking function can be maintained. 
   The reinforcing plate  101  is an extension of the spring  50 . Thus, there is no need to produce the reinforcing plate  101  and the spring  50  separately. Accordingly, the number of parts can be reduced and the construction can be simplified. 
   The invention is not limited to the above described and illustrated embodiments. For example, the following embodiments are also embraced by the technical scope of the present invention as defined by the claims. Beside the following embodiments, various changes can be made without departing from the scope and spirit of the present invention as defined by the claims. 
   The spring is made of a leaf spring material in the foregoing embodiments. However, the spring member may be, for example, a coil spring or a member made of a cushioning material such as rubber or any other resilient material according to the invention. 
   The loose movement preventing portions are in the receiving portions in the foregoing embodiments. However, they may be in the latches according to the present invention. In short, it is sufficient for the loose movement preventing portions to surround three sides of the latches or the receiving portions when they are engaged to prevent loose movements thereof. 
   The loose movement preventing portions prevent loose movement of the latches and the receiving portions when being engaged with each other in the foregoing embodiments. However, it is sufficient to provide protrusions for filling clearances between the latches and the receiving portions, so that the latches and the receiving portions can be engaged rigidly by the protrusions. 
   The latches and the receiving portions engage to lock the inner housing in the outer housing in the foregoing embodiments. However, the latches and the receiving portions may not be provided with such a locking mechanism according to the invention. 
   The spring has four supports arranged at intervals in the foregoing embodiments. However, the spring may have more or fewer supports according to the present invention. 
   A reinforcing plate formed separately from the spring may be mounted into the lock arm according to the present invention. 
   The male connector may be provided with the inner housing, the outer housing, the spring and the like according to the present invention. 
   The lock arm may have a locking projection engageable with the interlocking portion instead of the locking hole according to the invention. 
   The male connector may include the lock arm and the female connector may include the interlocking portion according to the present invention. 
   The metallic reinforcing plate may cover the entire engageable surface of the lock arm according to the invention so that the reinforcing plate contacts the entire locking surface of the interlocking portion. 
   In view of vibration resistance, the female connector may not be comprised of many components such as the inner housing, but may be an ordinary connector having one housing as a major part.