Abstract:
A floating connector is disclosed with an inner housing that is movably held within an outer housing. The connection between the inner and outer housing is effected by terminals with increased flexibility. Fitting nails are provided that serve as stops to limit the upward movement of the inner housing relative to the outer housing.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates generally to electrical connectors, and more specifically to floating connectors having a first connector portion movably attached to a second connector portion and wherein the first connector portion is capable of movement relative to the second connector portion. 
         [0002]    Board-to-board connectors are commonly used to electrically connect a pair of parallel circuit boards together. In some cases, the relative positions of the connected circuit boards deviate from their preset positions. In order to absorb such a positional deviation between the circuit boards, floating-style connectors have been used. Japanese Utility Model Publication (kokoku) No. 07-33408 illustrates one such type of connector. 
         [0003]      FIG. 9  is a sectional, perspective view of a conventional floating-type connector. In  FIG. 9 , the connector includes an outer housing  301  that is attached to a circuit board (not shown). A recess  303  is formed in the outer housing  301 , and an inner housing  302  is accommodated in the recess  303  so as to move in the X-, Y-, and Z-axis directions. A stopper frame  306  restricts the movement of the inner housing  302  in the X-axis direction, while the inner walls of the recess  303  restrict the movement of the inner housing  302  in the Y-axis direction; and stopper pieces  304  of the inner housing  302  and upper pieces  305  of the outer housing  301  restrict the movement of the inner housing  302  in the Z-axis direction. 
         [0004]    Terminals  308  extend between the outer housing  301  and the inner housing  302 . Each terminal  308  is fixed to the outer housing  301  so one end thereof projects exterior of the outer housing  301 , and is fixed to the inner housing  302  so that the other end projects into the interior of the inner housing  302 . A terminal intermediate portion  309  is formed in a wave-like manner, and elastic deformation of this intermediate portion  309  allows the inner housing  302  to move relative to the outer housing  301 . In this manner, the inner housing  302  “floats” in relation to the outer housing  301 . 
         [0005]    However, in the such a conventional floating-style connector, since the intermediate portion  309  of the terminal  308  is bent merely in a wavy form, the length of the elastically deformable portion may be insufficient and the terminal  308  fails to exhibit high flexibility. Also, since the trough portion of the wavy form abuts a lower corner portion of the inner housing  302 , (shown at the end of the arrow in the lower right corner of  FIG. 9 ) the extent of elastic deformation of the terminal  308  is restricted accordingly. As a result, the flexibility of the terminal  308  drops. When many of these type terminals  308  are used in the connector, the inner housing  302  fails to flexibly move relative to the outer housing  301  so that deviation between the circuit boards cannot be fully absorbed. 
         [0006]    Since movement in the Z-axis direction is restricted by means of the stopper pieces  304  of the inner housing  302  and the upper pieces  305  of the outer housing  301 , upon subjection to a strong force in the Z-axis direction at the time of removal of a counterpart connector, there is risk of the upper pieces  305  of the outer housing  301  being deformed. 
         [0007]    The present invention is directed to a floating-style connector that overcomes the aforementioned disadvantages. 
       SUMMARY OF THE INVENTION 
       [0008]    It is therefore a general object of the present invention to provide an improved floating-style connector having and inner housing encompassed by an outer housing, the inner housing being movable relative to the outer housing in the X, Y and Z directions. 
         [0009]    Another object of the present invention is to provide a floating-style connector which has terminals with straight portions extending in parallel with a circuit board, the straight portions connecting the attachment portions of the terminals together, and the inner housing of the connector being raised with respect to the outer housing so as to define a space between the lower surface of the inner connector housing and the upper surfaces of the terminal straight portions so that the inner housing is movable relative to the outer housing, the upward movement of the inner housing being limited by a series of stops supported by the outer connector housing. 
         [0010]    A still further object of the present invention is to provide a floating-style connector of the receptacle construction wherein a connector inner housing is held within a central opening of a connector outer housing, the inner and outer housings being interconnected by terminals that extend through the two housings, the terminals including vertical loop portions interposed between contact and tail portions of the terminals and wide horizontal straight portions interposed between the vertical loop portions and the contact portions to provide a larger range of movement of the inner connector housing with respect to the outer connector housing. 
         [0011]    Yet an additional object of the present invention is to provide a floating-style connector of the type having an inner connector housing that is flexibly connected to an encompassing outer connector housing by a plurality of conductive terminals, the inner connector housing being capable of movement in the X, Y and Z direction, the outer connector housing including a plurality of fitting nails for mounting the outer connector housing to a circuit board, the fitting nails including stop members that project toward and above the inner connector housing and serve to provide stop surfaces therefor that limit movement of the inner connector housing in the Z direction. 
         [0012]    In order to achieve the above objects, a floating-style connector in accordance with the principles of the present invention is provided with an insulative outer housing having two spaced-apart longitudinal side walls and an open recess defined in the space between the side walls. An insulative inner connector housing is accommodated within the recess and is movable relative to the outer housing. A plurality of elastically deformable, conductive terminals connect the two housings together. Each terminal includes a tail portion for connecting to a circuit board, a contact portion to contact a terminal of a counterpart, mating connector. The terminals have body portions that extend between their respective contact and tail portions. 
         [0013]    The body portions of each terminal further includes a first attachment portion attached to the outer connector housing, a second attachment portion attached to the inner connector housing, and a freely deformable portion having a general “L” shape between the first and the second attachment portions. This freely deformable portion includes a horizontally straight portion extending horizontally and a vertically straight portion extending vertically and connecting, preferably at an angle of about 90 degrees, with the horizontally straight portion. The first attachment portion and the vertically straight portion may be considered as forming a vertical loop. 
         [0014]    Preferably, the inner connector housing includes a center wall and an engagement wall, the center wall extending vertically and parallel to the side walls of the outer connector. The terminal second attachment portions are attached to a lower end of the inner housing. 
         [0015]    In another embodiment of a floating-style connector constructed in accordance with the principles of the present invention, the outer housing includes side walls that define a center open area that receives an inner housing which is movable in relation to the outer housing, and a plurality of elastically deformable terminals with tail portions for connecting to a circuit board, and a contact portions for mating with counterpart terminals of a counterpart connector. The terminals are attached to the outer and inner housings and serve to physically connect the two housings together. The outer housing further includes restricting thick walls formed at opposing ends, and two restricting end walls that connect to the restricting thick-walls. These end walls are located opposite each other at each opposing ends of the outer housing. The inner housing includes end walls formed at longitudinally opposing ends thereof and the end walls face the restricting end walls, and the fitting nails are attached to the restricting thick-walls. These fitting nails include respective stop portions extending above the end walls. 
         [0016]    Each of the fitting nails preferably includes a vertical body portion attached to the outer connector restricting thick-wall, an attachment portion connected to the lower end of the outer housing and to the circuit board, and stop portion connected to an upper end of the body portion which extends horizontally out over a portion of the inner connector housing. 
         [0017]    The outer and inner housings may be formed integrally with each other such that the restricting end wall portions and the corresponding to-be-restricted end wall portions are connected together by means of respective connection portions. Subsequently, the connection portions are removed so as to separate the outer housing and the inner housing from each other. 
         [0018]    According to the floating-type connector of the present invention, each terminal includes a straight portion extending parallel to the circuit board to which the connector is mounted. This straight portion is horizontal and forms part of the freely (unrestricted) deformable portion of each terminal that connects the outer and inner housings together. Also, a space is provided between a lower surface of the inner housing and the upper surfaces of these terminal straight portions. Thus, the terminals exhibit high flexibility, so that the inner housing is movable relative to the outer housing. The fitting nails reliably resist upward forces applied to the inner housing during detachment of the connector assembly, thereby preventing deformation of the outer housing and terminals, as well as detachment of the terminal tail portions from the circuit board, thereby increasing the reliability of the connector. 
         [0019]    These and other objects, features and advantages of the present invention will be clearly understood through a consideration of the following detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    In the course of this detailed description, the reference will be frequently made to the attached drawings in which: 
           [0021]      FIG. 1  is a perspective view showing a connector assembly with two connector halves which combined form a board to board connector assembly in accordance with the principles of the present invention; 
           [0022]      FIG. 2  is a plan view of the bottom half (or receptacle) connector of the connector assembly of  FIG. 1 ; 
           [0023]      FIG. 3  is a sectional view of the connector of  FIG. 2 , taken along line A-A thereof; 
           [0024]      FIG. 4  is a perspective view of a terminal used in the receptacle connector of  FIG. 2 ; 
           [0025]      FIG. 5  is a cross-sectional view of an end portion of the receptacle connector of  FIG. 2  and taken along line B-B thereof; 
           [0026]      FIG. 6  is a perspective view, partially in section of the receptacle connector of  FIG. 2 , taken along line B-B of  FIG. 2  to illustrate the metal fitting nail in place within the receptacle connector; 
           [0027]      FIG. 7  is a perspective view of a portion of the bottom surface of the receptacle connector of  FIG. 2 ; 
           [0028]      FIG. 8  is a perspective view of a fitting nail used in the receptacle connector of  FIG. 2 ; and, 
           [0029]      FIG. 9  is a sectional, perspective view of a conventional floating-type connector. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0030]      FIG. 1  is a perspective view of a floating-style connector assembly which utilizes a floating-type receptacle connector  10  constructed in accordance with the principles of the present embodiment. The connector  10  is a surface mount connector which is mounted on the surface of a circuit board. A counterpart connector  50  which mates with the floating connector  10  is also a surface mount connector that is mounted on the surface of another circuit board. The connector  10  of the present embodiment and the counterpart connector  50  are mated together to form the connector assembly and electrically connect the two circuit boards together. In the present embodiment, terms for expressing direction, such as up, down, left, right, front, and rear, are used for explaining the structure and action of respective portions of the connector  10 . However, these terms represent respective directions for the case where the connector  10  is used in an orientation shown in the drawings, and must be construed to represent corresponding different directions when the orientation of the connector  10  is changed. 
         [0031]    As shown in  FIG. 2 , the connector  10  includes an outer housing  11  and an inner housing  21  which are both formed of an electrically insulative material, such as a synthetic resin. The outer and inner housing  11 ,  21  are mutually independent and separate members. However, when the outer housing  11  and the inner housing  21  are formed by a molding process, such as by injection molding, they may be formed together and subsequently separated from each other by conventional means. The outer housing  11  is shown as a rectangular member that includes two longitudinal and generally parallel side walls  12  that are spaced apart from each other. 
         [0032]    There are thick-walls  13  formed at opposite ends of each of the side walls  12  and restricting end walls  14  in parallel with each other, extending in the lateral direction of the connector  10  (in the vertical direction in  FIG. 2 ), and integral with the restricting thick-walls  13  which face the respective restricting end walls  14 . Opposite ends of each of the restricting end walls  14  are preferably formed integrally with corresponding ends of the restricting thick-walls  13 . The central recess of the outer connector housing  11  is therefore cooperatively defined by the side walls  12 , the restricting thick-walls  13 , and the restricting end walls  14 . 
         [0033]    The inner housing  21  is also shown as a rectangular member that includes a longitudinal center wall  22 , two engagement walls  23  that extend longitudinally on opposite sides of the center wall  22 , two engagement groove portions  24  extending longitudinally between the center wall  22  and a corresponding engagement wall portion  23  and, two to-be-restricted end wall portions  27  integral with respective longitudinally opposite ends of the center wall portion  22  and engagement wall portions  23 . In  FIG. 2 ,  27   e  and  27   f  denote opposite side surfaces of the to-be-restricted end wall portions  27 . The external size of the inner housing  21  is smaller than the internal size of the outer housing  11 , and the inner housing  21  is accommodated in the accommodation recess portion of the outer housing  11 . 
         [0034]    The connector  10  has a plurality of conductive terminals  31  that are arranged in a predetermined spacing in two rows extending lengthwise of the connector  10 . They are attached to the connector  10  so as to connect together and extend between the outer and inner housing  11 ,  21 . The terminals  31  are attached to the side walls  12  of the outer housing  11  and to the center wall  22  of the inner housing  21 , thereby physically connecting the outer housing  11  and the inner housing  21  together. The connector  10  is a floating-type connector; i.e., where the outer housing  11  and the inner housing  21  are not fixed together, but rather are connected together by the terminals  31 . The terminals  31  are elastic and deformable, so that the inner housing  21  is connected to the outer housing  11  in a movable, or floating condition. 
         [0035]    The outer housing  11  is surface mounted to a circuit board (not shown). The connection is accomplished by way of the terminal tail portions and the metal fitting nails  41 . The fitting nails  41  are attached to attachment portions  15  formed on the restricting thick-wall portions  13 . 
         [0036]    The mating connector  50  ( FIG. 1 ) includes a counterpart connector housing  51  formed of an insulative material which supports a plurality of conductive counterpart terminals  52 . The mating connector housing  51  is also rectangular and includes projection portions that are inserted into the corresponding engagement groove portions  24  of the inner housing  21  are formed on the lower surface in  FIG. 1  of the counterpart housing  51 , and the counterpart terminals  52  are partially exposed from the lower surface. Also, the counterpart terminals  52  are partially exposed from the upper surface in  FIG. 1  of the counterpart housing  51 , and the exposed portions are connected, by soldering or the like, to corresponding connection pads connected to corresponding electrically conductive traces on an unillustrated another circuit board. 
         [0037]    As shown in  FIG. 1 , while the engagement surface (upper surface in  FIG. 1 ) of the connector  10  and the engagement surface (lower surface in  FIG. 1 ) of the counterpart connector  50  face each other, the connector  10  and/or the counterpart connector  50  are moved toward each other so as to engage the connector  10  and the counterpart connector  50  together. By this procedure, the terminals  31  of the connector  10  come into contact with the corresponding counterpart terminals  52  of the mating connector  50 , thereby establishing electrical connection therebetween. As a result, the paired circuit boards on which the connector  10  and the mating connector  50  are mounted respectively are electrically connected together. 
         [0038]    As shown in  FIG. 3 , a plurality of vertical first terminal accommodation grooves  16  are formed in the side walls  12  of the outer housing  11  at predetermined pitch spacings in a longitudinal row of the connector  10 . A plurality of vertical second terminal accommodation grooves  26  are formed in the side walls of the center wall  22  of the inner housing  21  at predetermined pitch spacings in a longitudinal row of the connector  10 . Each terminal  31  is accommodated in a single set of first and second terminal accommodation grooves  16 ,  26 . Some terminals  31  may be eliminated as appropriate in accordance with the terminal array of mating connector  50 . 
         [0039]    In  FIG. 3 , for convenience of illustration, only some of the first terminal accommodation grooves  16 , second terminal accommodation grooves  26 , and terminals  31  are illustrated, and illustration of the first terminal accommodation grooves  16 , second terminal accommodation grooves  26 , and terminals  31  present in intermediate regions of the rows extending in the longitudinal direction of the connector  10  is omitted. 
         [0040]    The inner housing engagement walls  23  are shown to have a generally L-shaped section disposed on the opposite side wall surfaces of the center wall  22 . Each of the engagement wall  23  is seen to include a vertical portion  23   a  and a horizontal portion  23   b . The engagement groove portion  24  is formed between the center wall  22  and the vertical portion  23   a  of each engagement wall  23 . The projections, including the terminals  52 , of the mating connector  50  are inserted into the engagement grooves  24 . The upper surface of each of the horizontal portion  23   b  serves as a bottom surface for each engagement groove  24 . The second terminal accommodation grooves  26  are formed in the center wall  22  along its length while extending through portions of the center wall  22  where the horizontal portions  23   b  merge into the side wall surfaces of the center wall  22 . 
         [0041]    As shown in  FIG. 4 , each of the terminals  31  is formed into a particular shape by bending a metal strip to have a side-view shape resembling the letter S. The terminal  31  includes a first attachment portion  32   a  attached to the outer housing  11 , a second attachment portion  32   b  attached to the inner housing  21 , a tail portion  33  for contact to circuit board, a contact arm portion  34  that contacts corresponding terminals  52  of the mating connector  50 , a freely deformable portion  35  which is freely deformable between the first and second attachment portions  32   a ,  32   b , and a selectively restricted deformable portion  36  extending between the first attachment portion  32   a  and the freely deformable portion  35 . By “freely deformable”, is meant that the movement (deformation) of the terminal in this area is not restricted as it is in the prior art connector of  FIG. 9 . 
         [0042]    Projections and dents are formed on the side surfaces of the first and second attachment portions  32   a  and  32   b . The projections of the first attachment portion  32   a  skive into the side walls of the first accommodation groove  16  of the outer housing  11 , and the projections of the second attachment portion  32   b  bite into the side walls of the second terminal accommodation groove  26  of the inner housing  21 , whereby the first and second attachment portions  32   a  and  32   b  are fixed to the outer and inner housings  11  and  21 , respectively. As shown in  FIG. 3 , the first attachment portion  32   a  is attached to near the bottom of the first terminal accommodation groove  16  of the outer housing  11 , and the second attachment portion  32   b  is attached to near the bottom of the second terminal accommodation groove  26 . 
         [0043]    The tail portion  33  extends laterally out from the bottom of the first attachment portion  32   a  exterior of the side walls  12  of the outer housing  11 . As shown in  FIG. 3 , the lower end of the first attachment portion  32   a  slightly projects downward beyond the lower surfaces of the side walls  12  of the outer housing  11 . The tail portion  33  is connected, by soldering or the like, to a pad of the circuit board. 
         [0044]    The contact arm portion  34  is a cantilevered arm projecting obliquely upward from the upper end of the second attachment portion  32   b  and has a contact projection  34   a  which is formed on a free end thereof. The contact projection  34   a  is formed to project toward the selectively restricted deformable portion  36 . As shown in  FIG. 3 , most of the contact arm portion  34  is received within the second terminal accommodation groove  26  of the inner housing  21 , and the contact projection  34   a  projects into the engagement groove portion  24  from the second terminal accommodation groove  26 . When the terminals  52 , of the mating connector  50  are inserted into the engagement groove portions  24 , the spring function of the contact arm portions  34  presses the contact projections  34   a  against the terminals  52 , thereby electrically connecting the terminals  31  and the counterpart terminals  52  together. 
         [0045]    The contact arm portions  34  are accommodated in the corresponding second terminal accommodation grooves  26 ; accordingly, the contact arm portions  34  are movable in the span direction of the terminals  31  (the connector lateral direction), but are not movable in the pitch direction of the terminals  31  (the connector longitudinal direction). Thus, the contact projections  34   a  are placed with respect to the pitch direction of the terminals  31  and in accurate contact with and electrically connected to the counterpart terminals  52 . 
         [0046]    The freely deformable portion  35  has a side-view shape resembling the letter L and includes a horizontal straight portion  35   a , a vertical straight portion  35   b , a first bend portion  35   c  bent at about 90 degrees and integral with one end of the horizontal straight portion  35   a  and with the lower end of the second attachment portion  32   b , a second bend portion  35   d  bent at about 90 degrees and integral with the other end of the horizontal straight portion  35   a  and with the lower end of the vertical straight portion  35   b , and a curved portion  35   e  curved at about 180 degrees and joining the upper end of the vertical straight portion  35   b  with the upper end of the selectively restricted deformable portion  36 . 
         [0047]    In this manner, the freely deformable portion  35  has a side-view shape resembling the letter L and is configured such that the second bend portion  35   d  is bent at about 90 degrees to the horizontal straight portion  35   a  and with the vertical straight portion  35   b  so that the portion is free from restriction by the outer or inner housing  11 ,  21 . In this manner, the freely deformable portion, assumes a long length between the first and second attachment portions  32   a ,  32   b  and is flexibly deformable so that the inner housing  21  flexibly moves relative to the outer housing  11 . In this case, the inner housing  21  is movable laterally, longitudinally and vertically relative to the outer housing  11 . It can also tilt from side to side. 
         [0048]    If the freely deformable portion  35  has such a side-view shape as to be gently curved and to extend between the first bend portion  35   c  and the curved portion  35   e , the length of the freely, elastically deformable portion will become short. As a result, the flexibility of the freely deformable portion  35  deteriorates, and thus the inner housing  21  fails to be flexibly movable in relation to the outer housing  11 . Particularly, in the case where the number of the terminals  31  is large (about 100), even when a difference in flexibility is small between different terminal shapes on the individual terminal basis of the terminals  31 , the small difference in flexibility greatly influences the flexibility of movement of the inner housing  21  in relation to the outer housing  11 , since the inner housing  21  is supported by means of all the terminals  31 . In the present embodiment, the freely deformable portion  35  has a side-view shape resembling the letter L, and the horizontally straight portion  35   a  and the vertically straight portion  35   b  are integral with each other via the second bend portion  35   d  which is bent at about 90 degrees. Thus, the flexibility of movement of the inner housing  21  in relation to outer housing  11  can be improved greatly. 
         [0049]    Also, since the freely deformable portion  35  has a side-view shape resembling the letter L, and the horizontal straight portion  35   a  and the vertical straight portion  35   b  are integral with each other via the second bend portion  35   d  which is bent at about 90 degrees ( FIG. 3 ), a space  25  is defined by the horizontal portion  23   b  of each of the engagement walls  23 , the center wall  22 , the horizontal straight portions  35   a , and the vertical straight portions  35   b . In other words, a lower corner portion of the inner housing  21  and the freely deformable portions  35  define a rectangular space  25 . Accordingly, even when the inner housing  21  is moved or tilted in relation to the outer housing  11  in the span direction of the terminals  31 , the inner housing  21  and the freely deformable portions  35  do not interfere with each other. Thus, the freely deformable portions  35  can be flexibly deformed without any restriction, and the inner housing  21  can flexibly move in relation to the outer housing  11 . Also, the freely deformable portions  35  are free from damage. 
         [0050]    The selectively restricted deformable portions  36  are received in the first terminal accommodation grooves  16 , and accordingly, the selectively restricted deformable portions  36  are movable in the lateral direction of the connector  10 , but are not movable in the longitudinal direction of the connector  10 . Accordingly, the freely deformable portions  35  are also restricted to a certain extent in movement in the pitch direction of the terminals  31 , whereby the distance between adjacent freely deformable portions  35  is maintained, and the adjacent freely deformable portions  35  do not contact with each other which would result in an unwanted shorting of the connector terminals. 
         [0051]    Next, the structure for restricting movement of the inner housing  21  relative to the outer housing  11  will be described. The outer and inner housings  11 ,  21  are connected together by means of the elastic terminals  31 , the inner housing  21  moves relative to the outer housing  11 . Movement of the inner housing  21  is restricted at longitudinally opposite end portions of the connector  10 . 
         [0052]    In this case, the to-be-restricted end walls  27  have a substantially rectangular block shapes and are preferably integral with the end portions of the center wall  22  and engagement walls  23 . Projections  27   b  and  27   c  are formed in the outer regions of each of the to-be-restricted end walls  27  to form therebetween a recess  27   a  located at the center of and extending vertically through the to-be-restricted end wall  27 . A downward projection  27   d  is formed on the lower surface of each of the to-be-restricted end walls  27 . 
         [0053]    The movement of the inner housing  21  relative to the outer housing  11  in the longitudinal direction of the connector  10 , is restricted by a portion of the end surface of each of the to-be-restricted end walls  27  of the inner housing  21 , and in the present embodiment, the longitudinal end surfaces of the projections  27   b  and  27   c  abut the inner wall surface of the corresponding restricting end wall  14  of the outer housing  11 . The movement of the inner housing  21  in the lateral direction of the connector  10 , is restricted by the side surfaces  27   e ,  27   f  of the to-be-restricted end wall  27 , abuttin the inner wall surfaces of the restricting thick-wall  13  of the outer housing  11 . 
         [0054]    Movement toward the circuit board (vertical) of the inner housing  21  is restricted by the lower surfaces of the downward projections  27   d , abutting the upper surfaces of the circuit board. Movement (upward) toward the mating connector  50  is restricted by a portion of the upper surfaces of the to-be-restricted end walls  27  abutting the fitting nails  41  attached to the restricting thick-walls  13  of the outer housing  11 . A tilting movement, in the span direction of the terminals  31 , of the inner housing  21  in relation to the outer housing  11  is restricted as follows: at least a portion of the lower surface of each of the to-be-restricted end wall portions  27  of the inner housing  21  abuts the upper surface of the circuit board, and at least a portion of the upper surface of each of the to-be-restricted end wall portions  27  abuts the fitting nails  41 . 
         [0055]    As shown in  FIGS. 5 and 7 , a downward projection  13   a  is formed on the lower surface of the restricting thick-wall  13 . The projection  13   a  is inserted into a positioning hole or the like formed on a circuit board, thereby positioning the outer housing  11  in relation to the circuit board. The number, position, and the like of the projections  13   a  may be determined as appropriate. The projection  13   a  may be eliminated as appropriate. 
         [0056]    As shown in  FIG. 8 , each of the fitting nails  41  is a member formed by bending a thick-walled metal strip having high strength and has a longitudinal, sectional shape resembling a crank. The fitting nails  41  includes a body portion  42  to be attached to the restricting thick-wall portion  13  of the outer housing  11 ; an attachment portion  43  to be attached, by soldering or the like, to a connection pad on a circuit board; and a stop portion  44  which extends above the to-be-restricted end wall portion  27  of the inner housing  21 . 
         [0057]    The body portion  42  has projections and dents formed on side surfaces. The projections bite into the side walls of the groove-like metal-member attachment portion  15  formed on the corresponding restricting thick-wall portion  13  of the outer housing  11 , whereby the body portion  42  is fixedly attached to the restricting thick-wall portion  13 . The attachment portion  43  extends laterally from the lower end of the body portion  42  toward the exterior of the outer housing  11 . The lower surface of the attachment portion  43  is attached, by soldering or the like, to a corresponding connection pad on the circuit board. The stop portion  44  extends laterally from the upper end of the body portion  42  toward the interior of the outer housing  11  and reaches a region above the corresponding to-be-restricted end wall  27  of the inner housing  21 . 
         [0058]    In other words, the stop portion  44  overlaps a region above at least a portion of the upper surface of the corresponding to-be-restricted end wall portion  27 ; in the present embodiment, a region above the upper surface of each of the projections  27   b  and  27   c  and not extending above the recess  27   a . In this case, as shown in  FIGS. 5 and 6 , since the stop portions  44  located at the laterally opposite sides of the connector  10  overlap at least a portion of the upper surface of the corresponding to-be-restricted end wall portion  27 , the to-be-restricted end wall portion  27  does not move upward through the space between the opposed stopper portions  44 . In a state shown in  FIGS. 5 and 6 , a gap exists between the lower surfaces of the stopper portions  44  and the upper wall surface of the to-be-restricted end wall  27 . 
         [0059]    When the inner housing  21  moves upward in relation to the outer housing  11 , a portion of the upper surface of each of the to-be-restricted end walls  27  of the inner housing  21 ; for example, in  FIG. 5 , left and right end portions of the to-be-restricted end wall portion  27  abut the lower surfaces of the stop portions  44 , thereby preventing further upward movement of the inner housing  21 . In this case, since the fitting nails  41  are of high strength, the stopper portions  44  are hardly deformed and reliably restrict an upward movement of the inner housing  21 . In the case where an upward movement of the inner housing  21  is associated with, for example, an operator&#39;s attempt to remove the counterpart connector  50 , a strong force is applied to the stopper portions  44 . However, since the stop portions  44  are hardly deformed, the stop portions  44  reliably restrict the upward movement of the inner housing  21 . 
         [0060]    The body portion  42  of each of the fitting nails  41  is attached to the corresponding restricting thick-wall  13 , which is thicker than the side wall  12  and has high strength. Thus, even when a strong force is applied to the stop portions  44 , the restricting thick-walls  13  to which the fitting nails  41  are attached are not deformed; therefore, the stop portions  44  reliably restrict an upward movement of the inner housing  21 . Furthermore, since the attachment portions  43  are attached, by soldering or the like, to corresponding connection pads on a circuit board, even when a strong force is applied to the stop portions  44 , the fitting nails  41  are not detached from the circuit board, and the stop portions  44  reliably restrict upward movement of the inner housing  21 . 
         [0061]    In the case where the inner housing  21  is tilted in the span direction of the terminals  31  in relation to the outer housing  11 , a portion of the upper surface of each of the to-be-restricted end walls  27  of the inner housing  21 ; for example, in  FIG. 5 , a left or right end portion of the to-be-restricted end wall  27  abuts the lower surface of the stop portion  44 , thereby preventing a further tilting movement of the inner housing  21 . 
         [0062]    Since the fitting nails  41  are attached to the corresponding opposite restricting thick-wall portions  13 , when an external force directed in the span direction of the terminals  31  is applied to the connector  10 , the fitting nails  41  prevent detachment of the tail portions  33  of the terminals  31  from corresponding connection pads connected to corresponding electrically conductive traces of a circuit board. Usually, the point of application of an external force which is applied to the connector  10  in the span direction of the terminals  31  is located above the surface of the circuit board. 
         [0063]    Thus, the external force generates such a rotation moment as to tilt the connector  10  in the span direction of the terminals  31 . The rotation moment generates such an upward force as to lift the side wall  12  corresponding to the side subjected to the external force; i.e., such a force as to move the side wall  12  away from the circuit board. Thus, the tails  33  of the terminals  31  fixed to the side wall  12  corresponding to the side subjected to the external force are subjected to a force which is directed in such a direction as to detach the tail portions  33  from the corresponding connection pads connected to the corresponding electrically conductive traces of the circuit board. 
         [0064]    However, as shown in  FIG. 7 , in the present embodiment, the attachment portion  43  of each of the fitting nails  41  is located on an extension line of a row of the terminal tails  33 . Thus, as in the case of the tail portions  33  of the terminals  31 , the attachment portions  43  of the fitting nails  41  attached to the restricting thick-walls  13  formed at opposite ends of the side wall  12  corresponding to the side subjected to the external force are also subjected to the force which is directed in such a direction as to make detachment from the circuit board. 
         [0065]    Accordingly, the attachment portions  43  of the fitting nails  41  bear a considerable portion of the force directed in such a direction as to make detachment from the circuit board, thereby reducing a force applied to the terminal tails and thus preventing detachment of the tails  33  from the pads of the circuit board. 
         [0066]    If the fitting nails  41  are not attached to the restricting thick-walls  13  formed at opposite ends of the side walls  12 , but are attached to central portions of the restricting end walls  14 , the attachment portions  43  are located away from the terminal tails  33  in terms of distance along the span direction of the terminals  31 . As a result, the attachment portions  43  fail to sufficiently function to bear the force directed in such a direction as to make detachment from the circuit board. Accordingly, a force applied to the terminal tails  33  is not reduced, and thus the terminal tails  33  may be detached from the pads of the circuit board. 
         [0067]    In the present embodiment, since the fitting nails  41  are attached to the restricting thick-walls  13  located at opposite ends of the outer housing  11  and at opposite sides of the to-be-restricted end walls  27  of the inner housing  21 , the manufacture of the connector  10  is facilitated. As mentioned previously, when the outer and inner housings  11 ,  21  are formed by a molding process, such as injection molding, they may be integrally formed in the same mold. In this case, the connector  10  is in such a state that all of the terminals  31  and the fitting nails  41  are removed from the connector  10  shown in  FIG. 1  or  2 . Furthermore, connection portions may be provided that connect the outer and inner housings  11 ,  21  together and these would extend between the to-be-restricted end walls  27  of the inner housing  21  and the restricting end walls  14  of the outer housing  11 . More specifically, rod-like connection portions extend between central portions of the to-be-restricted end walls  27  and central portions of the restricting end walls  14 . The connection portions maintain the outer housing  11  and the inner housing  21  in the positional relation shown in  FIG. 1  or  2 . 
         [0068]    In a state that the connection portions are present, the terminals  31  are attached to the outer housing  11  and to the inner housing  21 , and the fitting nails  41  are attached to the outer housing  11 . In this case, since the connection portions maintain the positional relation between the outer housing  11  and the inner housing  21 , the step of attaching the terminals  31  to both of the outer housing  11  and the inner housing  21  can particularly be facilitated. 
         [0069]    After completion of attachment of the terminals  31  and the connector-attaching auxiliary metal members  41 , the connection portions are preferably cut off. In this case, since the fitting nails  41  are attached to the corresponding restricting thick-walls  13  located at opposite sides of each of the to-be-restricted end walls  27  to thereby leave a space between the stop portions  44  of the fitting nails  41  as shown in  FIGS. 5 and 6 , the connection portions which connect central portions of the to-be-restricted end walls  27  and central portions of the restricting end walls  14  respectively together can be readily cut off. Accordingly, the manufacture of the connector  10  can be facilitated. 
         [0070]    If the fitting nails  41  are not attached to each of the restricting thick-walls  13 , but are attached to a central portion of each of the restricting end walls  14 , the stop portion  44  is located above each of the connection portions. This disables the cutting off of the connection portions until after the fitting nails  41  are attached. In order to cope with this problem, in the course of manufacture of the connector  10 , in a state that the connection portions are present, the terminals  31  are attached, and after completion of attachment of the terminals  31 , the connection portions are cut off. After completion of cutting-off of the connection portions, the fitting nails  41  are attached. In this case, the same processing apparatus can be used for attaching the fitting nails  41  and attaching the terminals  31 . However, the same processing apparatus cannot be used for cutting off the connection portions and attaching the terminals  31 . 
         [0071]    Thus, after completion of attachment of the terminals  31 , setups are changed; furthermore, after completion of cutting-off of the connection portions, setups are again changed. As a result, the frequency of setup increases, causing an increase in man-hours required for manufacturing the connector  10 . By contrast, according to the present embodiment, after completion of attachment of the terminals  31  and the fitting nails  41 , the connection portions are cut off. Thus, changing setups is performed only once, thereby reducing man-hours required for manufacturing the connector  10 ; i.e., facilitating the manufacture of the connector  10 . 
         [0072]    Since the fitting nails  41  are attached to the corresponding restricting thick-wall  13  located at opposite ends of the outer housing  11  and at opposite sides of the to-be-restricted end walls  27  of the inner housing  21 , the recess  27   a  can be formed on an end portion, with respect to the longitudinal direction of the connector  10 , of each of the to-be-restricted end wall portions  27 . As mentioned previously, a connection portion extending to the corresponding restricting end wall  14  is formed on the end portion, with respect to the longitudinal direction of the connector  10 , of each of the to-be-restricted end walls  27 . By means of providing the recess  27   a  and forming the connection portions in the corresponding recess  27   a , space around the individual connection portions increases, thereby facilitating mold design for forming the connection portions, and facilitating cutting-off of the connection portions. The provision of the downward projections  27   d  also contributes to an increase in space around the individual connection portions, thereby yielding a similar effect. Notably, the recess  27   a  may be eliminated as needed. 
         [0073]    As described above, in the present embodiment, each of the terminals  31  includes the first attachment portion  32   a  attached to the outer housing  11 , the second attachment portion  32   b  attached to the inner housing  21 , and the freely deformable portion  35  having a shape resembling the letter L and freely deformable between the first attachment portion  32   a  and the second attachment portion  32   b . The freely deformable portion  35  includes the horizontal straight portion  35   a  and the vertical straight portion  35   b  extending at an angle of about 90 degrees to the horizontal straight portion  35   a.    
         [0074]    Thus, the freely deformable portion  35  has a long, freely, elastically deformable length and thus can be flexibly deformable. Therefore, the inner housing  21  can flexibly move in relation to the outer housing  11 . 
         [0075]    The center wall  22  and horizontal portion  23   b  of the inner housing  21  and the horizontal straight portions  35   a  and vertical straight portions  35   b  of the freely deformable portions  35  of the terminals  31  are disposed so as to define a rectangular space  25 . Accordingly, even when the inner housing  21  is moved or tilted in relation to the outer housing  11  in the span direction of the terminals  31 , the inner housing  21  and the freely deformable portions  35  do not interfere with each other. Thus, the freely deformable portions  35  can be flexibly deformed without any restriction, and the inner housing  21  can flexibly move in relation to the outer housing  11 . Also, the freely deformable portions  35  are free from damage. 
         [0076]    Furthermore, no particular limitation is imposed on the sectional shape of the space  25 . For example, the center wall  22  and the horizontal portion  23   b  may be obliquely integral with each other to thereby form a space having a triangular section or may be arcuately integral with each other to thereby form a space having a quadrant section, so long as such a structural feature does not restrict the movement of the horizontal straight portions  35   a  and vertical straight portions  35   b.    
         [0077]    The outer housing  11  includes the restricting thick-walls  13  formed at opposite ends of the side wall portions  12 , and two restricting end walls  14  each connecting with the restricting thick-walls  13  opposing each other at opposite ends of the outer housing  11 ; the inner housing  21  includes two to-be-restricted end walls  27  formed at longitudinally opposite ends, a longitudinal end surface of each of the to-be-restricted end walls  27  facing the corresponding restricting end wall  14 , laterally opposite side surfaces of each of the to-be-restricted end walls  27  facing the corresponding restricting thick-walls  13 ; and the fitting nails  41  are attached to the corresponding restricting thick-walls  13 , each of the fitting nails  41  including the stop portion  44 , the stop portions  44  of the fitting nails  41  attached to the corresponding restricting thick-walls  13  located on laterally opposite sides of each of the to-be-restricted end walls  27 , extending above the upper surface of the to-be-restricted end wall  27 . 
         [0078]    Accordingly, a horizontal movement of the inner housing  21  in relation to the outer housing  11  is restricted by means of the to-be-restricted end walls  27  abutting the restricting thick-walls  13  and the restricting end walls  14 . A vertical movement of the inner housing  21  in relation to the outer housing  11  is restricted by means of the to-be-restricted end walls  27  abutting the stop portions  44  of the fitting nails  41 . 
         [0079]    In this case, the fitting nails  41  are attached to the corresponding restricting thick-walls  13  which are thick and have high strength. Thus, even when a strong force is applied to the stop portions  44 , the restricting thick-walls  13  are not deformed; therefore, the stop portions  44  reliably restrict an upward movement of the inner housing  21 . Furthermore, since the fitting nails  41  are attached, by soldering or the like, to pads on a circuit board, even when a strong force is applied to the stopper portions  44 , the fitting nails  41  are not detached from the circuit board, and the stop portions  44  reliably restrict an upward movement of the inner housing  21 . 
         [0080]    The attachment portions  43  of the fitting nails  41  are attached to the circuit board in alignment with the terminal tail portions  33 . Accordingly, when an external force directed in the span direction of the terminals  31  is applied to the connector  10 , the tail portions  33  of the terminals  31  are prevented from being detached from their connection pads of the circuit board. 
         [0081]    Furthermore, the outer housing  11  and the inner housing  21  are formed integral with each other such that the restricting end walls  14  and the to-be-restricted end walls  27  are connected together by means of respective connection portions; subsequently, the connection portions are removed so as to separate the outer housing  11  and the inner housing  21  from each other. Accordingly, the manufacture of the connector  10  can be facilitated. 
         [0082]    The present invention is not limited to the above-described embodiment. Numerous modifications and variations of the present invention are possible in light of the spirit of the present invention, and they are not excluded from the scope of the present invention.