Patent Publication Number: US-2007117435-A1

Title: Coaxial connector having a switch

Description:
BACKGROUND OF THE INVENTION  
      The present invention relates to a coaxial connector for mounting on a circuit board, especially a coaxial connector having a switch, which has a switching mechanism to switch a high-frequency signal circuit.  
      In a portable communication device, such as a cellular phone, a coaxial connector having a switch is widely used for checking a high-frequency circuit. As a conventional coaxial connector having a switch, for example, the applicant of this patent application disclosed in Unexamined Japanese Patent Application Publication No. 2003-123915.  
      The conventional coaxial connector  21 A disclosed in the aforementioned patent publication is illustrated in  FIGS. 21-23 .  FIG. 21  is a vertical cross-sectional view taken along the center line of the conventional connector  21 A, which is illustrated with a coaxial plug that can be used for turning on/off the switch,  FIG. 22  is a front perspective view of the conventional connector  21 A, and  FIG. 23  is a backside perspective view of the conventional connector  21 A.  
      As shown in  FIG. 21 , the coaxial plug  26 A can be attached/detached to/from the conventional connector  21 A from the upper side of the connector  21 A. The coaxial plug  26 A includes an insulated housing  27 A having a generally cylindrical shape, an outer conductor  28 A that covers the insulated housing  27 A, and center conductor  29 A, which is provided along the center axis of the insulated housing  27 A. The outer conductor  28 A and the center conductor  29 A protrude below the insulated housing  27 A, and can be elastically displaced upward.  
      On the other hand, the conventional connector  21 A includes an insulated housing  22 A having a hole  35 A to receive the center conductor  29 A of the coaxial plug  26 A, an outer conductor  23 A provided outside of the insulated housing  22 A, a stationary terminal  24 A and a movable terminal  25 A, which are provided below the hole  35 A. Furthermore, the stationary terminal  24 A has a contact section  40 A, and the movable terminal  25 A has a securing section  42 A secured to the insulated housing  22 A and an elastic section  44 A that can touch the center conductor  29 A of the coaxial plug  26 A and can contact with the contact section  40 A.  
      In this conventional connector  21 A, when the coaxial plug  26 A is not attached as shown in the solid line in  FIG. 21A , the movable terminal  25 A presses the contact section  41 A of the stationary terminal  24 A by an elastic force of the elastic section  44 A, and the stationary terminal  24 A and the movable terminal  25 A maintain the electrical connection.  
      On the other hand, in the conventional connector  21 A, when the coaxial plug  26 A is attached as shown with the imaginary line (the dashed-two dotted line) in  FIG. 21 , the lower edge  33 A of the outer conductor  28 A fits into the annular groove  32 A of the outer conductor  23 A, and the lower end of the center conductor  29 A is inserted to the vertical hole  35 A. At this time, if the coaxial plug  26 A is pressed down, the outer conductor  28 A is compressed against the elastic force, and the center conductor  29 A protrudes below the outer conductor  28 A, and contacts with the elastic section  44 A at a specified contacting position. At this time, since the elastic force of the center conductor  29 A is stronger than that of the elastic section  44 A, as shown with the imaginary line in  FIG. 21 , the elastic section  44 A is pressed down by the center conductor  29 A and elastically deformed, and moves away from the contact section  40 A. The stationary terminal  24 A and the movable terminal  25 A are electrically disconnected, and at the same time, the center conductor  29 A and the movable terminal  25 A are connected. Accordingly, the high-frequency circuit can be checked by transmitting the signals, which are originally transmitted from the movable terminal  25 A to the stationary terminal  24 , from the movable terminal  25 A to the center conductor  29 A.  
      In the above-described conventional connector  21 , even after the movable terminal  25 A and the stationary terminal  24  are mounted in the insulated housing  22 A, since the hole  51 A to insert the movable terminal  25 A, especially its elastic section  44 A, into the insulated housing  22 A and the hole  80 A to insert the stationary terminal  24 A to the insulated housing  22 A are kept open, an alien substance can get in the product therefrom, and may adversely affect the contact between the signal terminals.  
     SUMMARY OF THE INVENTION  
      In view of the problems in the conventional technique, it is an object of the invention to provide a coaxial connector having a covering structure to reduce the entry of an alien substance in the product.  
      The invention relates to a coaxial connector having a switch, which is mounted on a circuit board, and is comprised of an insulated housing having a hole to accept a center conductor of the coaxial plug from the upper side, an outer conductor that can be attached to/detached from the outer conductor of the coaxial plug, a stationary terminal and a movable terminal, which are provided below the hole and can contact to/move away from each other. The stationary terminal has a contact section, and the movable terminal has a securing section to secure the movable terminal to the insulated housing, and an elastic section, which is provided inside the insulated housing through a insert hole provided in the insulated housing, extends from the securing section like a cantilever, can touch the center conductor of the coaxial plug, and can contact with the contacting section. The coaxial connector has a covering section to cover the insert hole. When the center conductor of the coaxial plug is fitted into the hole of the insulated housing, the center conductor touches the elastic section, and the elastic section moves way from the contact section.  
      In the above-described connector, the covering section can be integrally formed as a part of the insulated housing. In the above connector, the covering section is formed by extending a part of the insulated housing so as to cover the insert hole and can be bent toward the insert hole to cover the insert hole.  
      In the above-described connector, a cut can be provided on the surface of the insulated housing on the side opposite to the bending side so as to easily bend the covering section.  
      In the above-described connector, the covering section can be formed so as to touch the protrusion, which protrudes from the insulated housing outside of the insert hole, when it covers the insert hole.  
      In the above connector, the outer conductor of the coaxial connector can have a pressing section to position and secure the covering section.  
      In the above connector, the pressing section can be formed by extending a part of the outer conductor along the covering section at the inserting side of the moveable terminal, and can be bent toward the insert hole.  
      In the above-described connector, a cut can be provided on the surface of the outer conductor on the same side as the bending side so as to easily bend to form the pressing section.  
      In addition, in the above connector, the pressing section can have a narrow section, where a cut was formed.  
      Moreover, in the above connector, the width of the pressing section in the direction horizontal to the bending direction of the pressing section is preferably smaller than that of the covering section in the direction horizontal to the bending direction of the covering section.  
      The invention is a coaxial connector having a switch, which mounted on a circuit board, and is comprised of an insulated housing having a hole to accept a center conductor of the coaxial plug from the upper side, an outer conductor that can be attached to/detached from the outer conductor of the coaxial plug, a stationary terminal and a movable terminal, which are provided below the hole and can contact with/move away from each other. The stationary terminal has a contact section, and the movable terminal has a securing section to secure the stationary terminal to the insulated housing, and an elastic section, which is arranged inside the insulated housing through a insert hole of the insulated housing, extends from the securing section like a cantilever, can touch the center conductor of the coaxial plug, and can contact with the contacting section. The coaxial connector has a covering section to cover the insert hole. When the center conductor of the coaxial plug is fitted into the hole of the insulated housing, the center conductor touches the elastic section, and the elastic section moves way from the contact section.  
      In the above connector, two side protrusions that protrude from the insulated housing can be provided so that a part of the stationary terminal is interposed between those side protrusions.  
      In addition, in the above connector, the contact section of the stationary terminal can have an isosceles triangle shape for the cross-section in the above-described inserting direction, and the side protrusions can protrude so as to be across near the two vertexes of the base of the isosceles triangle.  
      In addition, in the above connector, the side protrusions can be integrally formed as a part of the insulated housing.  
      According to the invention, entry of alien substances inside the product can be prevented easily by a simple structure. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a cross-sectional view of the coaxial connector according to the invention, taken along the center line.  
       FIG. 2  is a front perspective view of the coaxial connector of  FIG. 1 .  
       FIG. 3  is a front view of the coaxial connector of  FIG. 1 .  
       FIG. 4  is a perspective view of the insulated housing before a movable terminal is mounted therein.  
       FIG. 5  is a perspective view of the insulated housing right after the movable terminal is mounted therein.  
       FIG. 6  is a backside perspective view of the coaxial connector illustrated in  FIG. 1 .  
       FIG. 7  is a backside view of the coaxial connector illustrated in  FIG. 1 .  
       FIG. 8  is a perspective view of the insulated housing before the stationary terminal is mounted therein.  
       FIG. 9  is a top view of the coaxial connector illustrated in  FIG. 1 .  
       FIG. 10  is a side view of the coaxial connector illustrated in  FIG. 1 .  
       FIG. 11  is a backside view of the coaxial connector of  FIG. 1 .  
       FIG. 12  is a cross-sectional view taken along line B-B of  FIG. 7 .  
       FIG. 13  is a front view of the insulated housing.  
       FIG. 14  is a top view of the insulated housing of  FIG. 13 .  
       FIG. 15  is a backside view of the insulated housing of  FIG. 13 .  
       FIG. 16  is a cross-sectional view taken along line C-C of  FIG. 14 .  
       FIG. 17  is a cross-sectional view taken along line D-D of  FIG. 15 .  
       FIG. 18  is a cross-sectional view taken along line E-E of  FIG. 13 .  
       FIG. 19  is a cross-sectional view taken along line F-F of  FIG. 13 .  
       FIG. 20  is a sectional view of an outer conductor.  
       FIG. 21  is a vertical cross-sectional view taken along the center line of the conventional connector, illustrated with a coaxial plug that can be used for turning on/off a switch.  
       FIG. 22  is a front perspective view of the conventional connector.  
       FIG. 23  is a backside perspective view of the conventional connector. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      An embodiment of the coaxial connector having a switch according to the invention will now be described with reference to the accompanying drawings.  
      A basic structure of the coaxial connector  21  is similar to that of the conventional coaxial illustrated in  FIGS. 21-23 . The coaxial connector  21  of the invention, however, has a covering structure to prevent entry of alien substances, which is significantly different from the conventional connector  21 A.  
      The whole view of the coaxial connector  21  of the invention is shown in  FIGS. 1-12 . In those figures, the members that correspond to those of the conventional connector  21 A in  FIGS. 21-23  are denoted by deleting “A” from the reference numerals in  FIG. 21-23 .  FIGS. 21-23  correspond to  FIGS. 1, 2  and  6 , which illustrate the invention. More specifically,  FIG. 1  is a cross-sectional view of the coaxial connector according to the invention, taken along the center line (cross-sectional view, taken along line A-A of  FIG. 9 ).  FIG. 2  is the front perspective view;  FIG. 3  is the front view;  FIG. 4  illustrates the insulated housing  22  before the movable terminal  25  is mounted therein;  FIG. 5  illustrates the insulated housing right after the movable terminal  25  is mounted therein;  FIG. 6  is the backside perspective view of the coaxial connector according to the invention;  FIG. 7  is the backside view;  FIG. 8  shows the insulated housing before the stationary terminal is mounted therein;  FIGS. 9-11  are the top view, side view, and back-side view of the coaxial connector of the invention, respectively; and  FIG. 12  is a cross-sectional view taken along line B-B of  FIG. 7 .  
       FIGS. 13-19  show individual component, especially the insulated housing of the coaxial connector illustrated in  FIGS. 1-12 .  FIG. 20  shows the individual component, especially the outer conductor  23  of the coaxial connector  21 . More specifically,  FIGS. 13-15  are the front view, the top view, and the backside view of the insulated housing  22 , respectively, and  FIG. 16  is a cross-sectional view taken along line C-C of  FIG. 14 .  FIG. 17  is a cross-sectional view taken along line D-D of  FIG. 15 ;  FIG. 18  is a cross-sectional view taken along line E-E of  FIG. 13 ; and  FIG. 19  is a cross-sectional view taken along line F-F of  FIG. 13 .  
      As fully shown in  FIG. 1 , the coaxial connector  21  having a switch according to the invention includes the insulated housing  22  that has generally rectangular parallelepiped shape and is made of a resin, such as plastic, the outer conductor  23  that is provided outside of the insulated housing  22  and is made of metal, and the stationary terminal  24  and the movable terminal  25 , at least a part of which is arranged in the insulated housing. The coaxial connector  21  can be mounted on a circuit board (not illustrated), and can form a part of a circuit board being connected to the circuit board via a board-connecting section  38  (fully illustrated in  FIG. 11 ) of the stationary terminal  24  or via a board-connecting section  35  of the movable terminal  25 , which are exposed outside.  
      An annular projecting rim  30  is provided along the outer circumference of the upper portion of the insulated housing  22 . An upper section  31  of the outer conductor  23  is provided being bent so as to cover the projecting rim  30 . An annular groove  32 , which has a semi-circular cross-section, is formed on the outer circumferential surface of the upper portion  31  of the outer conductor  23 , and the annular groove  32  can fit to the lower edge section  33  (see  FIG. 21 ) of the outer conductor  28  of the coaxial plug  26 . In addition, a conical opening  34  is formed on the upper side of the insulated housing  22 , and is concentrically connected to a vertical hole  35  on the bottom of the opening  34 . In addition, horizontally long space  36  connected to the vertical hole  35  is formed under the vertical hole  35 , and once the coaxial plug  26  is fitted, the lower end of the center conductor  29  is inserted through the vertical hole  35  and reach the space  36 .  
      As fully shown in  FIG. 4 , the movable terminal  25  has a flat securing section  42 , the board-connecting section  43  which is bent downward at the base of the securing section  42  to form a U-shape, and has an elastic section  44  that obliquely extends upward like a cantilever from the securing section  42 . The elastic section  44  can touch the center conductor  29  (see  FIG. 21 ), and can contact with the lower edge of the contact section  40  at a position closer to the end of the elastic section than where the elastic section  44  touches the center conductor  29 . A wedge-shaped protrusion  45  is formed on each side portion of the securing section  42 , and the securing section  42  is horizontally pressed into the space  36  through the insert hole  50  of the insulated housing  22  from the side opposite to the side to pressing the stationary terminal  24 . The elastic section  44  becomes wider toward the securing section  42  of the movable terminal  25  if it is viewed from the touching position with the center conductor  29 , and its side edges  46  there are curved inward. Moreover, the elastic section  44  has a cutout section at a position closer to the securing section than the touching position, and this cutout section  47  extends along the elastic section  44 , and preferably has a generally triangle shape along the shape of the side edges  46 .  
      As fully shown in  FIG. 8 , the stationary terminal  24  has a flat securing section  37 , a board-connecting section  38  provided at the edge being bent downward so as to form a square-bottomed U-shape, and an arm  48 , and is formed so as not to prevent the movement of the center conductor  29  in the axial direction. Here, the width L 8  of the securing section  37  in its width direction is set much larger than the width L 7  of the arm  48 . A wedge-shaped protrusion  39  is formed on the sides of the securing section  37 . The securing section  37  is horizontally pressed into the space  36  via the protrusions  39  through the insert hole  80  of the insulated housing from the side of the insulated housing  22 . As a result, while the securing section  37  is disposed in the insulated housing  22 , the other sections, arm  48  and the board-connecting section  38 , are left exposed to the outside of the insulated housing  22 . In addition, a contact section  40  (see  FIG. 1 ) protruding downward is provided at almost center portion of the securing section. This contact section  40  is formed by pushing and bending downward after making a cut along the base of the isosceles triangle, so as to precisely determine the position to contact with the elastic section  44 . The contact section  40  has an isosceles triangle shape for the cross-section in the horizontal inserting direction.  
      As fully shown in  FIGS. 1-4 ,  16  and  19 , a part of the side edge of the insulated housing on the side of inserting the movable terminal  25  extends so as to cover the insert hole  50  on the side of inserting the movable terminal  25 . This extending section  53  can be bent toward the insert hole  50  (i.e., downward) from the straight position so as to cover the insert hole  50 . In other words, the extending section  53  can be used as a covering section to cover the insert hole  50 . The insert hole  50  has two insert hole sections; a first insert hole section  51  that is relatively small but has a larger width corresponding to the securing section  42  of the movable terminal  25  but does not have a large height; and a second insert hole section  52 , which is relatively large but has narrow width corresponding to the elastic section  44  of the movable terminal  25  but has large height. Here, the insert hole section that needs to be covered with the covering section  53  is only the second insert hole section  52 . The first insert hole section  51  is almost completely covered when the securing section  42  of the movable terminal  25  is pressed therein. The covering section  53  preferably has a generally wide rectangular shape, corresponding to the shape of the second insert hole  52 . As shown in  FIGS. 13 and 3 , the width L 1  of the covering section  53  in the lateral (or the width) direction, i.e. the direction horizontal to the bending direction, is larger than the width L 2  of the second insert hole section  52 , and as shown in  FIG. 3 , the height L 3  of the covering section in the longitudinal direction (the direction vertical to the bending direction) at the time of bending is as large as it reach the upper edge of the securing section  42  of the movable terminal  25 . As a result, the second insert hole section can be almost completely covered by the covering section  53 .  
      The covering section  53  can be integrally formed as a part of the insulated housing  22 . In order to easily bend the covering section  53 , V-shaped cut  55  is provided in the lateral direction at a specified position on the insulated housing surface opposite to the bending side. In order to easily bend, a specified length of a cut groove  54  can be provided near the center of the edge of the covering section  53 . When the covering section  53  is bent and covers the second insert hole section  52 , the covering section  53  can touch the projecting section  57  of the insulated housing  22  at its inside, i.e. the side that is bent. This projecting section  57  is a section that protrudes from the insulated housing  22  up to a position between the outermost wall  58 , which protrudes most outward from the insulated housing wall on the side of the insert hole  50  and the innermost wall  59  that is receded most. Once the covering section  53  touches the projecting section  57 , the incompleteness caused by the cut  55  of the covering section  53  can be solved and the insert hole  50  can be more surely covered.  
      Corresponding to the covering section  53 , a part of the side edge of the outer conductor  23  extends on the side of inserting the movable terminal  25  along the covering section  53 . This extending section  70  can be bent toward the insert hole (i.e. downward) so as to cover a part of the upper part of the covering section  53 . In other words, this extending section  70  can be used as a pressing section  70  to position and secure the covering section  53 . The shape of the pressing section  70  is not specifically limited, but for example, it can be generally rectangular shape having a narrow width as in the figure. As shown in  FIG. 3 , the width L 4  of the pressing section  70  in the lateral or the width direction (the horizontal direction to the bending direction) is set smaller than the width L 1  of the covering section  53  in the direction. Even by setting the width in this way, since the outer conductor  23  is made of hard metal, the covering section is considered to work well as a pressing section. In addition, by setting the dimensions in this way, it can reduce concern of generating noise signals that can be caused when the outer conductor  23 , which can also work as a ground, gets close to the movable terminal  25 .  
      Similarly to the covering section  53 , the pressing section  70  can be integrally molded as a part of the outer conductor  23 . A V-shaped cut  71  is provided along the lateral direction at a specified position on a surface of the outer conductor on the same side as the bending side, so as to be able to easily bend. Here, being different from the cut  55  of the insulated housing  22  provided on the surface opposite to the bending side, the cut  71  of the pressing section  70  is provided on the same side of the surface as the bending side, so as to be able to fully exhibit the effects on the covering section  53 .  
      At the time of forming the pressing section  70 , the visual inspection groove  11  (see  FIGS. 21 and 22 ) can be used. The visual inspection groove  11  is usually used to check the direction of the current flow on the board, but by changing the shape of the visual inspection groove, i.e. by forming a narrow section  73  tapering the width towards the cut  71  of the pressing section  70 , the pressing section  70  can be easily bent at a specified position.  
      The pressing section  70  can be bent at the same time of bending the covering section  53  of the insulated housing  22 , but can be bent after bending the covering section of the insulated housing  22 . Here, if they are bent simultaneously, the work can be simplified.  
      As fully shown in  FIGS. 6-8 , the insulated housing  22  has a insert hole  80  having a shape that corresponds to the cross-section of the securing section  37  in the direction of pressing the securing section  37  on the side of pressing the securing section  37  of the stationary terminal  24 . Similarly to the insert hole  50 , the insert hole  80  has two insert hole sections; a first insert hole section  81  that has a large width but does not have large height corresponding to the securing section  37  of the stationary terminal  24  inserted in the insert hole  80 ; and a second insert hole section  82  that has a isosceles triangle shape corresponding to the contact section  40  of the stationary terminal  24 . Here, the first insert hole section  81  is almost completely covered when the securing section  37  of the stationary terminal  24  is pressed therein, but the second insert hole section  82  is covered to a certain degree by the flat arm  48 , which is a part of the stationary terminal  24 , but will not be completely covered. In order to cover it completely, a wall surface of the insulated housing on the sides of the insert hole  80  is used in this invention. More specifically, a side protrusion  83 , which protrudes to the outside of the insulated housing, is provided so as to be arranged on the both sides of the arm  48 . In order to achieve the effect of preventing entry of alien substances, those side protrusions  83  are preferably provided as close as possible to the arm  48 . For example, those protrusions are provided so as to extend through near two vertexes of the bottom of a isosceles triangle shape of the second insert hole section  82 . Here, it is satisfactory as long as the side protrusions  83  are provided so as to cover the second insert hole section on the both sides of the arm  48 . For example, as illustrated in the figure, they can be provided only as a part of the surface of the insulated housing  22 , or can be provided over the whole area of the surface except the portion covered by the arm  48  (i.e. the areas of the side protrusions and the area around the protrusions  86 ). In addition, the side protrusions  83  can be integrally formed as a part of the insulated housing  22 , but can be formed as a separate piece from the insulated housing. Here, in order to even more completely cover the hole section by the arm  48 , the distance L 6  between the two vertexes of the bottom of the isosceles that forms the cross-section of the second insert hole section  82  is preferably set generally same as the width L 7  of the arm  48 .  
      The invention can be applied to various connector devices that require prevention of entry of alien substances. Therefore, the application of the invention is not limited to coaxial connectors.