Patent Publication Number: US-9905968-B2

Title: Coaxial connector with floating mechanism

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The contents of the following Japanese patent application and international application are incorporated herein by reference, 
     Japanese Patent Application No. 2015-154172 filed on Aug. 4, 2015, and 
     International Application No. PCT/JP2015/84864 filed on Dec. 7, 2015. 
     FIELD 
     The present invention relates to a coaxial connector that is used in connecting an electronic device and a coaxial cable, connecting electronic devices, etc. In particular, the present invention relates to a coaxial connector with a floating mechanism which provides excellent connectability between a plug and a socket. 
     BACKGROUND 
     A socket of a coaxial connector of this type includes a socket-side center contact which is arranged at the center of the socket, and a socket-side shell which is arranged outside the socket-side center contact. If the socket is connected with a plug, the socket-side center contact and the socket-side shell both need to be appropriately connected with a plug-side center contact and a plug-side shell of the counterpart. 
     Depending on the mounting positions of the socket and the plug with respect to support members such as a substrate and a chassis built in an electronic device, axial and radial positional deviations may occur between the socket and the plug to be connected with each other. In connecting the coaxial connectors, such positional deviations need to be corrected. 
     A socket with a floating mechanism has thus been used as a socket of a related coaxial connector (for example, see Patent Literature 1). The socket with a floating mechanism includes a socket main body which is movably supported in radial directions (x- and y-axis directions) with respect to a socket base portion. The socket main body is connected with a plug. The socket base portion is fixed to a support member such as a substrate and a casing. 
     The socket base portion includes a socket-side shell of cylindrical shape, a center conductor portion, an insulating member, and biasing means such as a coil spring and a disc spring. The socket-side shell movably holds the socket main body. The center conductor portion is arranged at the center of and within the socket-side shell. The insulating member insulates the center conductor portion from the socket-side shell. The biasing means radially bias the socket main body held by the socket-side shell. With such a configuration, the socket main body and the coaxial connector of the counterpart can be connected to each other even if axially misaligned. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: Japanese Patent Application Laid-Open No. 2008-262736 
     SUMMARY 
     Technical Problem 
     A coaxial connector of this type is desired to correct not only a positional deviation in the radial directions (x- and y-axis directions) but also a positional deviation in the axial direction (z-axis direction) if the plug and the socket are supported by respective different support members and the support members are assembled into a set. 
     However, related coaxial connectors with a floating mechanism are often configured to allow movement of the socket main body with respect to the socket base portion in only the radial directions (x and y directions). For a positional deviation in the axial direction (z-axis direction), somewhat large connection tolerance or the like is set between the plug and socket. The absorption of the positional deviation in the axial direction may produce an axial gap between the plug-side shell and the socket-side shell, which can degrade performance and affect the shielding characteristic. 
     According to the related technique described in Patent Literature 1, the socket main body which is interconnected with the coaxial connector of the counterpart and the socket base portion which movably holds the socket main body are separately provided. Thus, there has been a problem that the external shape of the entire socket becomes accordingly greater, hampering miniaturization. 
     Related techniques such as described in Patent Literature 1 need a coil spring or disc spring for biasing the socket main body in the axial or radial directions. Thus, there has been a problem that the parts count increases accordingly, causing an increase in the product cost and the manufacturing steps. 
     Moreover, in this type of related coaxial connector with a floating mechanism, the center contact of the socket main body and the center conductor of the socket base portion are separately formed, and the socket main body is configured to be radially movable with respect to the socket base portion. This needs a structure for movably and electrically connecting the center contact and the center conductor to each other. There has thus been a problem of a complicated structure. 
     High-frequency performance is important to the coaxial connector of this type. If the center contact moves together with the socket main body to cause an axial misalignment between the center contact and the center conductor of the socket base portion, the high-frequency performance may drop. 
     Solution to Problem 
     In view of such conventional problems, the present invention has been achieved to provide a coaxial connector with a floating mechanism which can maintain high high-frequency performance and floating performance, has less parts count, and is capable of miniaturization. 
     To solve the foregoing conventional problems and achieve the intended object, a first aspect of the invention provides a coaxial connector with a floating mechanism, including a plug and a socket to be connected to each other, the plug including a plug-side center contact that is arranged at a center, a plug-side shell that is arranged outside the plug-side center contact, and a plug-side insulator that is interposed between the plug-side center contact and the plug-side shell, the socket including a socket-side center contact that is arranged at a center, a socket-side shell that is arranged outside the socket-side center contact, and a housing that holds the socket-side center contact and the socket-side shell in a mutually insulated state, the housing including a housing base portion that is fixed to a support member, and a housing movable portion that is radially movable over a plug-side end face of the housing base portion along with the socket-side center contact, a top side of the plug-side shell being fitted onto the housing movable portion, wherein the socket-side shell integrally includes a shell contact plate portion that is exposed from the plug-side end face of the housing base portion, and an end of the plug-side shell is configured to make contact with the shell contact plate portion. 
     A second aspect of the invention is characterized, in addition to the configuration of the first aspect, by that a contact plate escape groove is circumferentially formed in the housing movable portion, and the shell contact plate portion is configured to be able to escape into the contact plate escape groove. 
     A third aspect of the invention is characterized, in addition to the configuration of the first or second aspect, by that a sliding contact portion of arc-like chamfered shape is formed on the end of the plug-side shell. 
     A fourth aspect of the invention is characterized, in addition to the configuration of any one of the first to third aspects, by that the plug-side shell includes a shell main body that holds the plug-side insulator, a movable shell of cylindrical shape that is axially movably held on a socket side of the shell main body, and a biasing spring that biases the movable shell to the socket side. 
     A fifth aspect of the invention is characterized, in addition to the configuration of any one of the first to fourth aspects, by that the housing includes a floating spring member that is fixed at one end to the housing base portion and at the other end to the housing movable portion, and the floating spring member includes a support fixed portion that is fixed to the housing base portion, a floating fixed portion that is fixed to the housing movable portion, and an elastically-deformable swing spring portion that connects the support fixed portion and the floating fixed portion, and the housing movable portion is movably supported by the housing base portion via the floating spring member. 
     A sixth aspect of the invention is characterized, in addition to the configuration of the fifth aspect, by that the socket-side center contact includes a contact portion that moves together with the housing movable portion, and a substrate connection terminal that is connected to a mounting substrate, the contact portion is integrally supported by the floating fixed portion of the floating spring member, the substrate connection terminal is integrally supported with the support fixed portion, and the socket-side center contact is integrated with the floating spring member. 
     A seventh aspect of the invention is characterized, in addition to the configuration of the fifth or sixth aspect, by that the socket-side shell includes a pair of elastic contact pieces that are opposed to each other at a distance in a direction crossing a direction from the support fixed portion to the floating fixed portion, the pair of elastic contact pieces being arranged outside the housing movable portions. 
     An eighth aspect of the invention is characterized, in addition to the configuration of any one of the first to seventh aspects, by that a plurality of housing movable portions are movably supported by the housing base portion. 
     As described above, the coaxial connector with a floating mechanism according to an aspect of the present invention is a coaxial connector including the plug and the socket that are connected to each other. The plug includes the plug-side center contact that is arranged at the center, the plug-side shell that is arranged outside the plug-side center contact, and the plug-side insulator that is interposed between the plug-side center contact and the plug-side shell. The socket includes the socket-side center contact that is arranged at the center, the socket-side shell that is arranged outside the socket-side center contact, and the housing that holds the socket-side center contact and the socket-side shell in a mutually insulated state. The housing includes the housing base portion that is fixed to the support member, and the housing movable portion that is radially movable over the plug-side end face of the housing base portion along with the socket-side center contact. The top side of the plug-side shell is fitted onto the housing movable portion. The socket-side shell integrally includes the shell contact plate portion that is exposed from the plug-side end face of the housing base portion. The end of the plug-side shell is configured to make contact with the shell contact plate portion. Even if the housing movable portion of the socket moves to correct a positional deviation in radial directions (x and y directions), no gap occurs between the plug-side shell and the socket-side shell therefore, whereby a high high-frequency characteristic and a high shielding characteristic can be maintained. 
     According to an aspect of the present invention, the contact plate escape groove is circumferentially formed in the housing movable portion. The shell contact plate portion is configured to be able to escape into the contact plate escape groove. The movement of the housing movable portion therefore will not be hampered even if the shell contact plate is provided. 
     According to an aspect of the present invention, the sliding contact portion of arc-like chamfered shape is formed on the end of the plug-side shell. The housing movable portion can thus move smoothly in the radial directions (x and y directions) with respect to the housing base portion even if the end of the plug-side shell is in contact with the shell contact plate portion. 
     According to an aspect of the present invention, the plug-side shell includes the shell main body that holds the plug-side insulator, the movable shell of cylindrical shape that is axially movably held on the socket side of the shell main body, and the biasing spring that biases the movable shell to the socket side. A positional deviation between the plug and the socket in the axial direction (z-axis direction) can thus be corrected to maintain a stable connection state between the plug and the socket. The plug-side shell can also be maintained in a stable contact state with respect to the shell contact plate portion. A high high-frequency characteristic and a high shielding characteristic can thus be obtained. 
     According to an aspect of the present invention, the housing includes the floating spring member that is fixed at one end to the housing base portion and at the other end to the housing movable portion. The floating spring member includes the support fixed portion that is fixed to the housing base portion, the floating fixed portion that is fixed to the housing movable portion, and the elastically-deformable swing spring portion that connects the support fixed portion and the floating fixed portion. The housing movable portion is movably supported by the housing base portion via the floating spring member. The portion to be interconnected with the plug and the portion constituting the floating mechanism can thus be integrally configured. This can miniaturize the connector and reduce the parts count. 
     According to an aspect of the present invention, the socket-side center contact includes the contact portion that moves together with the housing movable portion, and the substrate connection terminal that is connected to the mounting substrate. The contact portion is integrally supported by the floating fixed portion of the floating spring member. The substrate contact terminal is integrally supported with the support fixed portion. The socket-side center contact is integrated with the floating spring member. This can reduce the parts count and simplify the assembly operation. Since the socket-side center contact follows the movement of the housing movable portion, a deviation of the center axes within the connector can be prevented to suppress a drop in the high-frequency performance. 
     According to an aspect of the present invention, the socket-side shell includes the pair of elastic contact pieces that are opposed to each other at a distance in the direction crossing the direction from the support fixed portion to the floating fixed portion, the pair of elastic contact pieces being arranged outside the housing movable portion. This allows the movement of the housing movable portion and the socket-side center contact in the direction between the two elastic contact pieces, and can establish reliable connection with the plug-side shell. 
     According to the present invention, a plurality of housing movable portions are movably supported by the housing base portion. Such a configuration is applicable to a multiple coaxial connector. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is an exploded perspective view showing an example of a coaxial connector with a floating mechanism according to an embodiment of the present invention. 
         FIG. 2A  is a longitudinal cross-sectional view showing the plug in  FIG. 1 . 
         FIG. 2B  is a bottom view of the plug in  FIG. 1 . 
         FIG. 3  is a reduced exploded perspective view of the plug. 
         FIG. 4A  is a longitudinal cross-sectional view of the socket in  FIG. 1 . 
         FIG. 4B  is a cross-sectional view taken along the line A-A of the socket in  FIG. 1 . 
         FIG. 5  is an exploded perspective view of the socket. 
         FIG. 6A  is a front view showing a floating spring member of the foregoing socket. 
         FIG. 6B  is a plan view of the floating spring member. 
         FIG. 6C  is a cross-sectional view taken along the line B-B of the floating spring member. 
         FIG. 6D  is a cross-sectional view taken along the line C-C of the floating spring member. 
         FIG. 7A  is a plan view showing a housing base portion of the foregoing socket. 
         FIG. 7B  is a cross-sectional view taken along the line D-D of the housing base portion. 
         FIG. 7C  is a cross-sectional view taken along the line E-E of the housing base portion. 
         FIG. 8A  is a plan view showing a socket-side shell of the foregoing socket. 
         FIG. 8B  is a cross-sectional view taken along the line F-F of the socket-side shell. 
         FIG. 8C  is a cross-sectional view taken along the line G-G of the socket-side shell. 
         FIG. 9A  is a front view showing a housing movable portion of the foregoing socket. 
         FIG. 9B  is a bottom view of the housing movable portion. 
         FIG. 9C  is a cross-sectional view taken along the line H-H of the housing movable portion. 
         FIG. 9D  is a cross-sectional view taken along the line I-I of the housing movable portion. 
         FIG. 10A  is a longitudinal cross-sectional view for describing an operation of the coaxial connector with a floating mechanism according to an embodiment of the present invention, showing a state in which a plug-to-socket distance is small. 
         FIG. 10B  is a longitudinal cross-sectional view for describing an operation of the coaxial connector with a floating mechanism according to an embodiment of the present invention, showing a state where the plug-to-socket distance is large. 
         FIG. 11A  is a longitudinal cross-sectional view for describing an operation of the coaxial connector with a floating mechanism according to an embodiment of the present invention, showing a state in which there is no axial misalignment. 
         FIG. 11B  is a longitudinal cross-sectional view for describing an operation of the coaxial connector with a floating mechanism according to an embodiment of the present invention, showing a state where there is an axial misalignment in a front-to-rear direction (x-axis direction). 
         FIG. 12A  is a longitudinal cross-sectional view for describing an operation of the coaxial connector with a floating mechanism according to an embodiment of the present invention, showing a state where there is no axial misalignment. 
         FIG. 12B  is a longitudinal cross-sectional view for describing an operation of the coaxial connector with a floating mechanism according to an embodiment of the present invention, showing a state where there is an axial misalignment in a lateral direction (y-axis direction). 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Next, an embodiment of the present invention will be described on the basis of an embodiment shown in  FIGS. 1 to 12 . In the diagrams, the reference numeral  1  represents a coaxial connector with a floating mechanism. 
     The coaxial connector  1  with a floating mechanism includes a plug  11  and a socket  12  which are connected to each other. The coaxial connector  1  with a floating mechanism is configured to be able to connect the plug  11  and the socket  12  while correcting positional deviations therebetween in radial directions (x- and y-axis directions) and an axial direction (z-axis direction) with the floating mechanism. 
     As shown in  FIGS. 2A, 2B, and 3 , the plug  11  includes a plug-side center contact  3 , a plug-side shell  4 , and an insulating plug-side insulator  5 . The plug-side center contact  3  is made of a conductive metal material and arranged at the center. The plug-side shell  4  is arranged outside the plug-side center contact  3 . The plug-side insulator  5  is interposed between the plug-side center contact  3  and the plug-side shell  4 . The plug-side insulator  5  and the plug-side center contact  3  are built in the plug-side shell  4 . 
     The plug-side center contact  3  is formed in a wire shape made of a conductive metal material. One end of the plug-side center contact  3  forms a contact portion  31  to make contact with a socket-side center contact  6 . The other end forms a terminal portion  32  to be connected to a coaxial cable or other electronic devices. 
     The plug-side insulator  5  is integrally molded of an insulating resin. The plug-side insulator  5  includes an insulator main body portion  51  of columnar shape and an expanded diameter cylinder portion  52  of cylindrical shape which protrudes from a rear end side of the insulator main body portion  51 . The plug-side insulator  5  including the insulator main body portion  51  and the expanded diameter cylinder portion  52  has a stepped protruded shape. 
     The plug-side center contact  3  is embedded in the insulator main body portion  51  of the plug-side insulator  5 , with both of its ends, i.e., the contact portion  31  and the terminal portion  32  protruded. 
     The expanded diameter cylinder portion  52  is formed in the shape of a closed-bottomed cylinder having an open top the outer diameter of which is greater than that of the insulator main body portion  51 . The terminal portion  32  protrudes from the bottom portion to the interior of the expanded diameter cylinder portion  52 . 
     The plug-side shell  4  includes a shell main body  41 , a movable shell  42 , and a biasing spring  43 . The shell main body  41  holds the plug-side insulator  5 . The movable shell  42  is axially movably supported on the plug  11  side of the shell main body  41 . The biasing spring  43  biases the movable shell  42  in a protruding direction. 
     The movable shell  42  is formed in a cylindrical shape by pressing or casting a conductive metal material. A retaining flange  421  protruding inward is integrally formed on one opening portion of the movable shell  42 . 
     A sliding contact portion  422  of arc-like chamfered shape is formed along the entire circumference of the socket  12  side end of the movable shell  42 . 
     The shell main body  41  is casted in a conductive metal material. The shell main body  41  is formed in the shape of a cylinder having an insulator accommodation hole  411  for accommodating the plug-side insulator  5  in the center. A movable shell accommodation groove  412  of circular groove shape is formed in a thick portion outside the insulator accommodation hole  411  so as to be opened in the end face on the socket  12  side. The movable shell  42  is inserted into the movable shell accommodation groove  412  in an extendable and retractable manner. 
     The insulator accommodation hole  411  is formed in a stepped hole shape such that an expanded diameter portion  411   a  and a reduced diameter portion  411   b  having different inner diameters are continuously arranged to communicate with each other. The plug-side insulator  5  is inserted into the insulator accommodation hole  411  from a top opening (end opening on the side opposite from the socket  12 ). The end face of the expanded diameter cylinder portion  52  of the plug-side insulator  5  comes into contact with a step portion  411   c , whereby the plug-side insulator  5  is held in the shell main body  41 . 
     In the drawing, the reference numeral  44  represents a sealing member such as an O ring. The sealing member  44  seals a gap between the shell main body  41  and the plug-side insulator  5 . 
     The movable shell accommodation groove  412  includes a sliding guide portion  412   a  of which the outer diameter is expanded to the shell side, and a spring holding portion  412   b  which communicates with the sliding guide portion  412   a . The biasing spring  43  and the movable shell  42  are successively inserted into the movable shell accommodation groove  412  from the shell-side opening. The retaining flange  412  can move in the axial direction as guided by the sliding guide portion  412   a.    
     A ring fitting portion  412   c  is circumferentially formed in the socket  12  side end of the inner diameter portion of the movable shell accommodation groove  412 . A stopper ring  45  is fitted to the ring fitting portion  412   c , so that the retaining flange  421  is stopped by the stopper ring  45 . 
     The biasing spring  43  is a coil spring made of conductive metal. The biasing spring  43  is inserted into the spring holding portion  412   b  of the movable shell accommodation groove  412  and supported by the shell main body  41  to press the retaining flange  421 . The biasing spring  43  thereby biases the movable shell  42  in the protruding direction. 
     In the plug-side shell  4 , the movable shell  42  is accommodated in the movable shell accommodation groove  412 . The outer peripheral surface or inner peripheral surface of the movable shell  42  is always in contact with the outer peripheral surface or inner peripheral surface of the movable shell accommodation groove  412 . The movable shell  42  and the shell main body  41  are thus in a conducting state. The conducting state of the shell main body  41  and the movable shell  42  is also always maintained via the biasing spring  43 . 
     As shown in  FIGS. 4A, 4B, and 5 , the socket  12  includes a socket-side center contact  6 , a socket-side shell  7 , and a housing  8 . The socket-side center contact  6  is arranged at the center. The socket-side shell  7  is arranged outside the socket-side center contact  6 . The housing  8  holds the socket-side center contact  6  and the socket-side shell  7  in a mutually insulated state. The socket  12  is configured to be engaged with the plug  11  so that their center contacts and shells are respectively connected to each other. 
     The housing  8  includes a housing base portion  81 , a housing movable portion  82 , and a floating spring member  9 . The housing base portion  81  is fixed to a support member such as a substrate and a casing of an electronic device. The housing movable portion  82  is located on an end face of the housing base portion  81  on the plug  11  side, and can move with the socket-side center contact  6  with respect to the housing base portion  81 . The floating spring member  9  is fixed at one end to the housing base portion  81  and at the other end to the housing movable portion  82 . The housing movable portion  82  and the socket-side center contact  6  are movably supported by the housing base portion  81  via the floating spring member  9 , whereby a floating mechanism is formed. 
     The socket-side center contact  6  and the floating spring member  9  are integrated into a floating spring member with a contact (hereinafter, referred to as an integral spring member)  99  which is made of a conductive metal plate member. The socket  12  uses the integral spring member  99  so that the socket-side center contact  6  can follow the movement of the housing movable portion  82 . 
     As shown in  FIGS. 6A to 6D , the integral spring member  99  is integrally formed by stamping and bending an elastic conductive metal plate member. The integral spring member  99  is configured such that the floating spring member  9  integrally supports the socket-side center contact  6  and the floating spring member  9  also serves as some of the components of the socket-side center contact  6 . 
     The floating spring member  9  includes a support fixed portion  91 , a floating fixed portion  92 , and a swing spring portion  93 . The support fixed portion  91  is fixed to the housing base portion  81 . The floating fixed portion  92  is fixed to the housing movable portion  82 . The swing spring portion  93  connects the support fixed portion  91  and the floating fixed portion  92  and is capable of elastic deformation. The support fixed portion  91  and the floating fixed portion  92  are arranged in parallel in front and behind at a distance therebetween. The elastic deformation of the swing spring portion  93  allows the floating fixed portion  92  to move back and forth and swing laterally with respect to the support fixed portion  91 . 
     The support fixed portion  91  is formed in a rectangular shape. One end of the swing spring portion  93  is integrally supported on the top end of the support fixed portion  91 . A substrate connection terminal strip  61  constituting the socket-side center contact  6  is horizontally extended from the bottom end of the support fixed portion  91 . 
     The swing spring portion  93  integrally includes an elastic expansion and contraction portion  931  and elastic twist portions. The elastic expansion and contraction portion  931  can expand and contract in a direction from the support fixed portion  91  to the floating fixed portion  92 , i.e., in a front-to-rear direction. The elastic twist portions can twist about an axis in the direction from the support fixed portion  91  to the floating fixed portion  92 . The expansion and contraction of the elastic expansion and contraction portion  931  allow movement of the floating fixed portion  92  in the front-to-rear direction with respect to the support fixed portion  91 . The twist of the elastic twist portions allows movement of the floating fixed portion  92  in the lateral direction with respect to the support fixed portion  91 . The floating fixed portion  92  can return to the original position by elasticity. 
     The elastic expansion and contraction portion  931  is extended obliquely downward with its top end supported by the upper edge of the support fixed portion  91  via a folded portion  932  which is bent in an arc shape. A horizontally-extended impedance adjustment portion  934  is integrally supported on the bottom end of the elastic expansion and contraction portion  931  via a folded portion  933 . 
     The bends in the two folded portions  932  and  933  allow the elastic expansion and contraction portion  931  to expand and contract in the direction from the support fixed portion  91  to the floating fixed portion  92 , i.e., in the front-to-rear direction and return to the original position by elasticity. 
     The impedance adjustment portion  934  is formed in the shape of a horizontally-extended narrow plate. One end of the impedance adjustment unit  934  is supported by the elastic expansion and contraction portion  931  via the folded portion  933 . The other end is integrally supported on the lower edge of the floating fixed portion  92  via a folded portion  935 . 
     The plate width of the impedance adjustment portion  934  in the lateral direction can be changed at the time of press molding. The width of the impedance adjustment portion  934  can be appropriately changed to adjust the impedance of the socket-side center contact  6  integrated with the floating spring member  9  to an appropriate value. 
     The folded portions  932 ,  933 , and  935  are formed to be narrower than the plate widths of the support fixed portion  91  and the floating fixed portion  92 . The folded portions  932 ,  933 , and  935  constitute the elastic twist portions of the swing spring portion  93 . 
     More specifically, if the floating fixed portion  92  makes a relative lateral movement with respective to the support fixed portion  91 , the folded portions  932 ,  933 , and  935  twist about the axis in the direction from the support fixed portion  91  to the floating fixed portion  92  to allow the lateral movement. The floating fixed portion  92  can return to the original position by elasticity. 
     The floating fixed portion  92  is formed in a vertically-directed rectangular shape. A bulging portion  921  of vertical projection shape is integrally formed in the center of the floating fixed portion  92  so as to bulge toward the support fixed portion  91 . Elastic sandwiching pieces  621  constituting a connection portion  62  of the socket-side center contact  6  are integrally supported on both lower sides of the floating fixed portion  92 . 
     The socket-side center contact  6  includes the connection portion  62  to be connected with the plug-side center contact  3 , and the substrate connection terminal strip  61  to be connected with a connection substrate. The connection portion  62  and the substrate connection terminal strip  61  are electrically connected via the floating spring member  9 . 
     The connection portion  62  includes a pair of elastic sandwiching pieces  621  which are laterally opposed to each other. The two elastic sandwiching pieces  621  sandwich the contact portion  31  of the plug-side center contact  3  of pin shape to establish connection with the plug-side center contact  3 . 
     The elastic sandwiching pieces  621  are formed in a vertically long strip shape. The lower side edges of the elastic sandwiching pieces  621  are integrally supported by support pieces  63  which are folded at right angles on the lower side edges of the floating fixed portion  92 . The elastic sandwiching pieces  621  are arranged to be laterally opposed to each other between the support fixed portion  91  and the floating fixed portion  92 . 
     The elastic sandwiching pieces  621  each have an inwardly-curved contact  622  at the top end. The plug-side center contact  3  is sandwiched between the mutually-opposed contacts  622 . 
     Retaining guide pieces  64  extended horizontally outward are integrally supported on the bottom ends of the elastic sandwiching pieces  621 . The retaining guide pieces  64  are stopped by the bottom end of the housing bottom portion  81  so as to be movable in the front-to-rear and lateral directions. 
     As shown in  FIGS. 7A to 7C , the housing base portion  81  is made of an insulating synthetic resin in the shape of a rectangular cylinder that is opened at the top and bottom and has front, rear, left, and right peripheral wall portions  811  to  814 . The housing movable portion  82  is attached to the top side of the housing base portion  81 . The integral spring member  99  is attached into the housing base portion  81  from the bottom side. The housing movable portion  82  and the housing base portion  81  are movably connected via the floating spring member  9 . 
     A vertically-directed support fixed portion press-in portion  815  is formed in the front peripheral wall portion  811 . The support fixed portion  91  of the floating spring member  9  is pressed into the support fixed portion press-in portion  815 , whereby one end of the floating spring member  9 , i.e., the support fixed portion  91  is fixed to the housing base portion  81 . 
     The front peripheral wall portion  811  also has an escape groove  816  which is opened at the inner surface side of the support fixed portion press-in portion  815  and communicates with the support fixed portion press-in portion  815 . This prevents the swing spring portion  93  from interfering with the peripheral wall portions  811  to  814 . 
     Consequently, the lower parts of the floating fixed portion  92  and the two elastic sandwiching pieces  621  of the integral spring member  99  are supported by the housing  8  via the swing spring portion  93  and movably accommodated in a hollow portion  817 . The upper parts of the floating fixed portion  92  and the two elastic sandwiching pieces  621  of the integral spring member  99  are protruded from the top opening of the hollow portion  817 . 
     Lower guide grooves  818  of recessed shape are formed in the lower surfaces of the left and right peripheral wall portions  813  and  814  of the housing base portion  81 . Upper guide grooves  819  of recessed shape are formed in the upper surfaces of the left and right peripheral wall portions  813  and  814  of the housing base portion  81 . The retaining guide pieces  64  of the integral spring member  99  are inserted into the lower guide grooves  818 . The retaining guide pieces  64  are guided by the guide grooves  818  and stopped by the upper edges of the guide grooves  818 , whereby the integral spring member  99  is retained. 
     The socket-side shell  7  made of a conductive metal material is attached to outside the housing base portion  81 . The housing base portion  81  is fixed to a support member such as a mounting substrate via the socket-side shell  7 . 
     As shown in  FIGS. 8A to 8C , the socket side shell  7  is integrally formed by pressing an elastic conductive metal plate member. The socket-side shell  7  includes a cylindrical portion  71  of rectangular cylindrical shape, a pair of elastic contact piece portions  72 , and shell contact plate portions  73 . The cylindrical portion  71  surrounds the outer periphery of the housing base portion  81 . The elastic contact piece portions  72  are integrally supported by left and right side plates  713  and  714  of the cylindrical portion  71 , respectively. The shell contact plate portions  73  are integrally supported on the top edges of front and rear side plates  711  and  712  of the cylindrical portion  71 . 
     Substrate connection portions  74  protruding outward are integrally formed on the lower edges of the front and rear side plates of the socket-side shell  7 . Fixed locking portions  75  of inwardly folded shape are integrally formed on the top edges of the left and right side plates. The fixed locking portions  75  are engaged with the left and right peripheral wall portions  813  and  814  of the housing bottom portion  81 , and the substrate connection portions  74  are soldered to a pattern on the mounting substrate. The housing base portion  81  is thereby fixed to the mounting substrate which is the support member, and the socket-side shell  7  is electrically connected to the mounting substrate. 
     The elastic contact piece portions  72  each include a pair of elastic support pieces  721  and a contact piece  722 . Bottom ends of the elastic support pieces  721  are integrally supported by the top edge of the left or right side plate  713  or  714 . The contact piece  722  is shaped to bridge the two elastic support pieces  721 . When seen in a side view, the contact piece  722  and the two elastic support pieces  721  form a gate shape. 
     Each elastic support piece  721  includes a spring base portion  721   a  and a support spring portion  721   b . The spring base portion  721   a  is extended obliquely outward from the top edge of the left or right side plate portion. The support spring portion  721   b  is extended obliquely inward from the end of the spring base portion  721   a . An end of the contact piece  722  is integrally supported on the end of the support spring portion  721   b.    
     The contact piece  722  is formed in an inwardly-curved L shape or inverted L shape. The contact piece  722  is configured so that the apex of the curved portion makes contact with the outer peripheral surface of the plug-side shell  4  (movable shell  42 ). 
     The shell contact plate portions  73  are formed in a narrow plate shape, bent inward from the top edges of the front and rear side plates. The shell contact plate portions  73  are configured to be exposed from the end face of the housing base portion  81  on the plug  11  side when the socket-side shell  7  is attached to the housing base portion  81 . 
     Arc-shaped notches  731  are formed in the center portions of the inner rims of the shell contact plate portions  73  so as not to interfere with the movement of the housing movable portion  82 . 
     As shown  FIGS. 9A to 9D , the housing movable portion  82  is integrally molded of an insulating synthetic resin, and includes a movable main body portion  821  of flat columnar shape, a protruded portion  822  of columnar shape, and sliding portions  823 . The protruded portion  822  protrudes from the bottom end of the movable main body portion  821 . The sliding portions  823  are extended laterally outward from the bottom end of the protruded portion  822 . A contact accommodation portion  824  of rectangular hole shape, opened at the bottom side, is formed through the movable main body portion  821  and the protruded portion  822 . 
     The housing movable portion  82  has a fixed portion press-in hole  825  which is formed in parallel with the contact accommodation portion  824  and opened at the bottom. If the housing movable portion  82  is attached to the top surface part of the housing base portion  81 , the floating fixed portion  92  protruding from the top end of the housing base portion  81  is pressed into the fixed portion press-in hole  825 . In addition, the contact portion  62  of the socket-side center contact  6 , i.e., the upper parts of the two elastic sandwiching pieces  621  are accommodated in the contact accommodation portion  824 . 
     A guide surface portion  821   a  of tapered shape, of which the diameter decreases upward, is formed on the outer peripheral part of the upper end of the movable main body portion  821 . The movable main body portion  821  also has a contact through hole  821   b  which is opened in the top end and communicates with the contact accommodation portion  824 . The plug-side center contact  3  of pin shape is inserted into the housing  8  through the contact through hole  821   b . The movable shell  42  of the plug-side shell  4  is guided by the guide surface portion  821   a  and fitted onto the housing movable portion  82 . 
     The opening rim of the contact through hole  821   b  is formed in a tapered shape to decrease in diameter downward so that the plug-side center contact  3  is guided toward the center of the hole. 
     The protruded portion  822  is formed in the shape of a flat circular column having an outer diameter smaller than that of the movable main body portion  821 . A contact plate escape groove  826  is circumferentially formed between the movable main body portion  821  and the sliding portions  823 , i.e., outside the protruded portion  822  so that the shell contact plate portions  73  can escape into the contact plate escape groove  826 . 
     The sliding portions  823  are passed through the upper guide grooves  819  formed in the upper ends of the left and right peripheral wall portions  813  and  814  of the housing base portion  81 . The sliding portions  823  are guided by the inner edges of the upper guide grooves  819  so that the housing movable portion  82  can move over the plug-side end face of the housing base portion  81 . 
     In the coaxial connector  1  with a floating mechanism configured thus, when the plug  11  and the socket  12  are mutually connected, the housing movable portion  82  is movably supported by the housing base portion  81  via the floating spring member  9  and moves with the socket-side center contact  6 . Even if there is an axial misalignment with respect to the plug  11  in any of the front, rear, right, and left directions (x and y directions) at the time of mutual connection, the axial misalignment can thus be automatically adjusted to provide a stable connection state. 
     In the coaxial connector  1  with a floating mechanism, the socket  12  includes the shell contact plate portions  73  which are exposed from the end face of the housing base portion  81  on the plug  11  side. The end of the plug-side shell  4  is put into contact with the shell contact plate portions  73 . This can provide a continuous shielding effect. 
     In the coaxial connector  1  with a floating mechanism, the plug-side shell  4  includes the movable shell  44  which is extendable and retractable from/into the end face of the shell main body  41  on the socket  12  side, and the biasing spring  43  which biases the movable shell  42 . This can absorb a positional deviation occurring between the plug  11  and the socket  12  in the axial direction (z-axis direction) to always maintain the end of the plug-side shell  4  in contact with the shell contact plate portions  73 . The plug-side shell  4  and the socket-side shell  7  can thus be connected without a gap in the axial direction, whereby a high shielding effect is provided. 
     Specifically, when the plug  11  and the socket  12  are connected, the movable shell  42  is biased by the biasing spring  43  and protruded from the plug-side end face of the shell main body  41 . The movable shell  42  therefore fits onto the housing movable portion  82  and makes contact with the elastic contact piece portions  72  of the socket-side shell  7 . The lower end of the movable shell  42  comes into contact with the shell contact plate portions  73  exposed from the plug-side end face of the housing base portion. The two shells  4  and  7  are thereby connected to each other. 
     If the movable shell  42  is fitted to the housing movable portion  82 , the plug-side center contact  3  is inserted into the housing movable portion  82  through the contact through hole  821   b , and the plug-side center contact  3  is connected with the socket-side center contact  6 . 
     The movable shell  42  in the state shown in  FIG. 10B  is then pressed in against the spring pressure of the biasing spring  43 . As shown in  FIG. 11A , the plug  11  and the socket  12  are thereby connected while absorbing a positional deviation in the axial direction (z-axis direction). 
     In other words, the coaxial connector  1  with a floating mechanism is configured to allow a positional deviation in the axial direction (z-axis direction) as much as the stroke of the movable shell  42  with respect to the shell main body  41 . 
       FIG. 11A  shows a case in which there is no positional deviation in the front-to-rear direction when the plug  11  and the socket  12  are connected.  FIG. 11B  shows a case in which there is a positional deviation between the plug  11  and the socket  12  in the front-to-rear direction. In the case shown in  FIG. 11B , the housing movable portion  82  and the plug  11  are guided by the guide surface portion  821   a  of the housing movable portion  82  toward mutual fitting. The elastic expansion and contraction portion  931  of the swing spring portion  93  bends and contracts in the front-to-rear direction to allow a movement of the housing movable portion  82  and the contact portion of the socket-side center contact  6  with respect to the housing base portion  81  in the front-to-rear direction. The plug-side center contact  3  and the socket-side center contact  6  are thus connected to each other. 
     Here, the plug-side shell  4 , or equivalently, the movable shell  42  moves in the front-to-rear direction while being fitted onto the housing movable portion  82  and sandwiched between the two elastic contact piece portions  72 . In addition, the lower end of the movable shell  42  slides over the shell contact plate portions  73 . The movable shell  42  is thus stably connected with the socket-side shell  7 . 
     If the plug  11  is detached, the bent elastic expansion and contraction portion  931  is elastically restored, and the housing movable portion  82  returns to the center position on the housing base portion  81  according to the deformation of the switch spring portion  93 . 
       FIG. 12A  shows a case in which there is no axial misalignment in the lateral direction.  FIG. 12B  shows a case in which there is an axial misalignment in the lateral direction. In the case shown in  FIG. 12B , the housing movable portion  82  and the plug  11  are guided by the guide surface portion  821   a  of the housing moving portion  82  toward mutual fitting. The elastic twist portions  932 ,  933 , and  935  of the swing spring portion  93  twist about the front-to-rear axis to allow a lateral movement of the housing movable portion  82  and the connection portion  62  of the socket-side center contact  6  with respect to the housing base portion  81 . The plug-side center contact  3  and the socket-side center contact  6  are thus connected to each other. 
     Here, the plug-side shell  4  is pressed against either one of the elastic contact piece portions  72  while being fitted onto the housing movable portion  82 . In addition, the lower end of the movable shell  42  slides over the shell contact plate portions  73 . The plug-side shell  4  is thus stably connected with the socket-side shell  7 . 
     If the plug  11  is detached, the bent elastic expansion and contraction portion  931  is elastically restored, and the housing movable portion  82  returns to the center position on the housing base portion  81  according to the deformation of the switch spring portion  93 . 
     As described above, in the coaxial connector  1  with a floating mechanism according to an embodiment of the present invention, a positional deviation in the axial direction (z-axis direction) can be allowed by the expansion and contraction of the movable shell  42  of the plug  11 . A positional deviation in the radial directions (x- and y-axis directions), i.e., to the front, rear, left, and right can be allowed in a composite manner. Specifically, a positional deviation in the front-to-rear direction can be allowed by the elastic expansion and contraction portion  931 . A positional deviation in the lateral direction can be allowed by the elastic twist portions  932 ,  933 , and  935 . The coaxial connector  1  with a floating mechanism is thus capable of floating in any direction. 
     Since the integral spring member  99  is used and the contact portion  62  of the socket-side center contact  6  is integrally supported by the floating fixed portion  92 , the center position of the socket-side center contact  6  moves with the floating operation to follow the center position of the plug-side center contact  3 . This can prevent the misalignment of the center axes within the connector. Since the housing movable portion  81  moves horizontally with respect to the housing base portion  81 , the movable shell  42  is prevented from lifting off the shell contact plate portions  73 . This can maintain high high-frequency performance and high shielding performance. 
     The foregoing embodiment has described an example where the support member that supports the housing  8  is configured as a mounting substrate built in an electronic component. However, the support member is not limited thereto. For example, the casing of an electronic device may be used as the support member. The housing  8  may be connected to a coaxial cable, and the coaxial cable may be used as the support member. 
     The coaxial connector  1  with a floating mechanism according to an embodiment of the present invention may be applied to a multiple coaxial connector in which a plurality of housing movable portions  82  are movably connected onto the housing base portion  81 . 
     REFERENCE SIGNS LIST 
     
         
         
           
               1  coaxial connector with floating mechanism 
               11  plug 
               12  socket 
               3  plug-side center contact 
               31  contact portion 
               32  terminal portion 
               4  plug-side shell 
               41  shell main body 
               411  insulator accommodation hole 
               412  movable shell accommodation groove 
               42  movable shell 
               43  biasing spring 
               44  sealing member 
               5  plug-side insulator 
               51  insulator main body portion 
               52  expanded diameter cylinder portion 
               6  socket-side center contact 
               61  substrate connection terminal strip 
               62  connection portion 
               621  elastic sandwiching piece 
               622  contact 
               63  support piece 
               64  retaining guide piece 
               7  socket-side shell 
               71  cylindrical portion 
               72  elastic contact piece portion 
               721  elastic support piece 
               722  contact piece 
               73  shell contact plate portion 
               74  substrate connection portion 
               75  fixed locking portion 
               8  housing 
               81  housing base portion 
               811  to  814  peripheral wall portion 
               815  support fixed portion press-in portion 
               816  escape groove 
               817  hollow portion 
               818  lower guide groove 
               819  upper guide groove 
               82  housing movable portion 
               821  movable main body portion 
               822  protruded portion 
               823  sliding portion 
               824  contact accommodation portion 
               825  fixed portion press-in hole 
               9  floating spring member 
               91  support fixed portion 
               92  floating fixed portion 
               921  bulging portion 
               93  swing spring portion 
               931  elastic expansion and contraction portion 
               932  folded portion 
               933  folded portion 
               934  impedance adjustment portion 
               935  folded portion 
               99  floating spring member with a contact (integral spring member)