Abstract:
A casing body is formed with a hole having an inner wall formed with a recess. A holder is made of resin and has an elastic retainer which is retractably projected from an outer peripheral face of the holder and engaged with the recess when the holder is fitted into the hole. A rod-shaped antenna element is held in the holder so as to movable between a first position being accommodated in the casing body and a second position being withdrawn from the casing body. The antenna element has a first power feeding portion and a second power feeding portion, the antenna element. A conductive contact member is disposed in the holder. A first portion of the contact member is brought into contact with the first power feeding portion when the antenna element is placed in the first position and with the second power feeding portion when the antenna element is placed in the second position. A second portion of the contact member is extended to the outside of the holder. A power feeding terminal is disposed in the casing body so as to come in contact with the second portion of the contact member.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to a structure which enables a rod-shaped antenna element to be mounted on a casing body of a portable phone or the like. The antenna element is movable between a position accommodated within the casing body and a position withdrawn from the casing body.  
         [0002]      FIGS. 13A and 13B  show a conventional structure for mounting a rod-shaped antenna.  FIG. 13A  shows the accommodated position, and  FIG. 13B  shows the withdrawal position.  
         [0003]     In this example, a casing body  10  is provided with a receiving holder  12  which is fixed thereto. A holder  14  made of conductive material is fixed to this receiving holder  12 , having a male thread  14   a  formed in the holder  14  screwed into a female thread  12   a  formed in the receiving holder  12 . A rod-shaped antenna element  16  is arranged in this holder  14  so as to be movable in an axial direction thereof.  
         [0004]     The rod-shaped antenna element  16  includes power supply parts  16   a ,  16   b  made of conductive material, at positions respectively opposed to the holder  14  in either of the accommodated position and the withdrawal position. The holder  14  is provided with a power supply spring  18  made of conductive material so as to be brought into elastic contact with the power supply parts  16   a ,  16   b , so that electrical connection is established between the power supply parts  16   a ,  16   b  and the holder  14  by way of this power supply spring  18 . Further, a power supply terminal  20  which is provided in the casing body  10  is brought into elastic contact with the holder  14 , so that the power supply parts  16   a ,  16   b  of the rod-shaped antenna element  16  are electrically connected appropriately to an electrical circuit which is contained in the casing body  10 . A top loading  22  is further provided on the rod-shaped antenna element  16 .  
         [0005]     The holder  14  is relatively heavy, because it is made of conductive metal. Moreover, the receiving holder  12  is also heavy, because it is generally made of metal, in order to form the female thread  12   a . Under the circumstance, as the antenna mounting structure for the portable phone or the like which is desired to be light-weight.  
       SUMMARY OF THE INVENTION  
       [0006]     It is therefore an object of the invention to provide an antenna mounting structure having light weight.  
         [0007]     In order to achieve the above object, according to the invention, there is provided an antenna mounting structure, comprising: 
        a casing body, formed with a hole having an inner wall formed with a recess at a first circumferential position;     a holder, made of resin and having an elastic retainer which is retractably projected from an outer peripheral face of the holder and engaged with the recess when the holder is fitted into the hole;     a rod-shaped antenna element, held in the holder so as to movable between a first position being accommodated in the casing body and a second position being withdrawn from the casing body, the antenna element having a first power feeding portion and a second power feeding portion, the antenna element;     a conductive contact member, disposed in the holder and comprises: 
            a first portion which is brought into contact with the first power feeding portion when the antenna element is placed in the first position and with the second power feeding portion when the antenna element is placed in the second position; and     a second portion extended to the outside of the holder; and    
            a power feeding terminal, disposed in the casing body so as to come in contact with the second portion of the contact member.        
 
         [0015]     Preferably, the retainer is a cantilevered piece.  
         [0016]     With the above configuration, the holder made of resin is fitted into the hole formed in the casing body and prevented from being detached therefrom by the retainer engaged with the recess formed in the inner wall of the hole. The light weight structure can be attained in comparison with the case where the holder is made of metal and the holder is further received by the receiving holder.  
         [0017]     Preferably, the holder includes a first section having an aperture from which the contact member is inserted, and a second section which closes the aperture.  
         [0018]     Here, it is preferable that the second portion of the contact member extends through a boundary between the first section and the second section of the holder.  
         [0019]     In this case, the assembling work of the holder incorporating the contact member can be facilitated.  
         [0020]     Preferably, an aperture edge of the hole is formed with a notch at the second circumferential position of the hole so as to allow the retainer to pass through when the holder is fitted into the hole.  
         [0021]     In this case, the insertion work of the holder can be facilitated. Further, the position of the retainer to be placed can be reliably recognized.  
         [0022]     Preferably, at least one of an outer face of the retainer and a bottom face of the recess is formed with a slanted face which causes the retainer to be retracted inward when the holder is rotated within the hole in a circumferential direction of the hole.  
         [0023]     In this case, it is possible to easily obtain a condition that the holder can be detached from the hole by the simple operation of rotating the holder.  
         [0024]     Here, it is preferable that: a projection is formed on the outer peripheral face of the holder; a first groove is formed on the inner wall of the hole at a second circumferential position so as to allow the projection to pass through when the holder is fitted into the hole; a second groove is formed on the inner wall of the hole at a third circumferential position at which the projection is placed when the holder is rotated to a position that the retainer is retracted; and a third groove is formed so as to connect the first groove and the second groove so as to allow the projection to pass through when the holder is rotated.  
         [0025]     In this case, the prevention of the detachment of the holder from the hole during the above rotating operation can be attained. Further, the circumferential position that the holder can be detached is reliable recognized.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]     The above objects and advantages of the present invention will become more apparent by describing in detail preferred exemplary embodiments thereof with reference to the accompanying drawings, wherein:  
         [0027]      FIG. 1A  is a section view of an essential part of an antenna mounting structure according to one embodiment of the invention, showing a state that an antenna element is at an accommodated position;  
         [0028]      FIG. 1B  is a section view of the essential part of the antenna mounting structure of  FIG. 1A , showing a state that the antenna element is at a withdrawal position;  
         [0029]      FIG. 2A  is a right side view of a holder in the antenna mounting structure;  
         [0030]      FIG. 2B  is a section view taken along a line IIB-IIB in  FIG. 2A ;  
         [0031]      FIG. 2C  is a section view taken along a line IIC-IIC in  FIG. 2D ;  
         [0032]      FIG. 2D  is a front view of the holder;  
         [0033]      FIG. 3A  is a top view of an upper section of the holder;  
         [0034]      FIG. 3B  is a front view of the upper section of the holder;  
         [0035]      FIG. 3C  is a right side view of the upper section of the holder;  
         [0036]      FIG. 3D  is a back view of the upper section of the holder;  
         [0037]      FIG. 3E  is a bottom view of the upper section of the holder;  
         [0038]      FIG. 3F  is a section view taken along a line IIIF-IIIF in  FIG. 3B ;  
         [0039]      FIG. 3G  is a section view taken along a line IIIG-IIIG in  FIG. 3C ;  
         [0040]      FIG. 4A  is a bottom view of a lower section of the holder;  
         [0041]      FIG. 4B  is a front view of the lower section of the holder;  
         [0042]      FIG. 4C  is a left side view of the lower section of the holder;  
         [0043]      FIG. 4D  is a section view taken along a line IVD-IVD in  FIG. 4B ;  
         [0044]      FIG. 4E  is a section view taken along a line IVE-IVE in  FIG. 4C ;  
         [0045]      FIG. 5A  is a front view of a power supply spring in the antenna mounting structure;  
         [0046]      FIG. 5B  is a top view of the power supply spring;  
         [0047]      FIG. 5C  is a right side view of the power supply spring;  
         [0048]      FIG. 6  is a view for explaining how to assemble the upper section of the antenna mounting structure, the power supply spring, and the lower section of the antenna mounting structure;  
         [0049]      FIG. 7  is a plan view of a mounting hole in the antenna mounting structure;  
         [0050]      FIG. 8  is a section view taken along a line VIII-VIII in  FIG. 1A ;  
         [0051]      FIG. 9  is a section view taken along a line IX-IX in  FIG. 1A ;  
         [0052]      FIG. 10  is a section view taken along a line X-X in  FIG. 1A ;  
         [0053]      FIG. 11  is a section view taken along the line IX-IX in  FIG. 1A , showing a state when the holder is to be detached;  
         [0054]      FIG. 12  is a section view taken along a line X-X in  FIG. 1A , showing the state of  FIG. 11 ;  
         [0055]      FIG. 13A  is a section view of an essential part of a conventional antenna mounting structure, showing a state that an antenna element is at an accommodated position; and  
         [0056]      FIG. 13B  is a section view of the essential part of the antenna mounting structure of  FIG. 13A , showing a state that the antenna element is at a withdrawal position.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0057]     Embodiments of the invention will be described below in detail with reference to the accompanying drawings.  
         [0058]     As shown  FIG. 1 , a casing body  10  of a portable phone or the like is provided with a mounting hole  30  which has a stepped part  30   a  so that a diameter of the mounting hole  30  may be enlarged at a side of an open end. This mounting hole  30  is provided, on its inner peripheral wall, with an engaging recess  30   b  adapted to be opposed to a tongue piece  42   a  of a holder  40  (will be described below), and an opening  30   c  adapted to be opposed to a tongue piece  50   b  of a power supply spring  50  (will be described below).  
         [0059]     The holder  40  is formed of resin, and divided in two along a dividing plane substantially perpendicular to an inserting direction, thereby to be composed of an upper section  44  and a lower section  42 .  
         [0060]     As shown in  FIG. 4 , the lower section  42  is provided, in its peripheral part, with the tongue piece  42   a  which is projected outwardly making an opposite side to the inserting direction as a free end, and which can be elastically deformed inwardly in a radial direction. The tongue piece  42   a  is provided with a slanted face from its base end at a lower side to the free end, so that the tongue piece  42   a  can be elastically deformed smoothly, inwardly in the radial direction, when the holder  40  is inserted into the mounting hole  30 . The tongue piece  42   a  is further provided with another slanted face  42   b  in a chamfered shape, on its one side in a circumferential direction.  
         [0061]     The lower section  42  is further provided, at its upper end, with a pair of engaging arms  42   c  projected in a direction opposite to the inserting direction, and engaging windows  42   d  are formed in respective distal end areas of the engaging arms  42   c . A pair of these engaging arms  42   c  serves to interconnect the lower section  42  and the upper section  44 . Moreover, a stopper  42   e  in a shape of a protrusion is provided on the peripheral part of the lower section  42  at the lower end area in the inserting direction.  
         [0062]     As shown in  FIG. 3 , the upper section  44  is provided with a stepped part  44   a  so that a diameter of the upper section  44  may be enlarged at an opposite side to the inserting direction. The stepped part  44   a  is brought into contact with the stepped part  30   a  of the mounting hole  30  thereby to restrict the insertion at a predetermined position. A peripheral part of the upper section  44  in front of the stepped part  44   a  in the inserting direction is clamped between a pair of the engaging arms  42   c  of the lower section  42 .  
         [0063]     The upper section  44  is further provided, on its face to be clamped, with engaging projections  44   b  which are adapted to be inserted into and engaged with the engaging windows  42   d  of the engaging arms  42   c . These engaging projections  44   b  also serve to interconnect the lower section  42  and the upper section  44 . When the upper section  44  is assembled to the lower section  42 , a pair of the engaging arms  42   c  are elastically deformed permitting the engaging projections  44   b  to be engaged with the engaging windows  42   d.    
         [0064]     The engaging windows  42   d  and the engaging projections  44   b  are formed in such a manner that they may not be easily detached in this engaged state, against a force in a direction of separating them. The upper section  44  is provided, on its upper end face, with grooves  44   c  for rotary operation which enable the upper section  44  to rotate in only one direction around the axis in the inserting direction. Further, there is formed a gap  44   d  through which the tongue piece  50   b  of the power supply spring  50 , which will be described below, is rendered to pass to be withdrawn.  
         [0065]     The power supply spring  50  is made of a sheet metal having elasticity such as beryllium copper, phosphor bronze and so on, and arranged on an inner peripheral face of the upper section  44 . As shown in  FIG. 5 , the power supply spring  50  is in a shape of a so-called barrel spring, including an elastic contact portion  50   a  adapted to come into contact with the power supply parts  16   a ,  16   b  of the rod-shaped antenna element  16 , and the tongue piece  50   b  to be extended to an outer peripheral side of the upper section  44 . A part interconnecting the elastic contact portion  50   a  and the tongue piece  50   b  is adapted to pass the gap  44   d  which is formed on the dividing plane between the lower section  42  and the upper section  44 .  
         [0066]     As shown in  FIG. 6 , the elastic contact portion  50   a  of the power supply spring  50  is incorporated into the upper section  44 , and then, the lower section  42  is assembled to the upper section  44 , while a pair of the engaging windows  42   d  of the engaging arms  42   c  are engaged with the engaging projections  44   b . In this manner, the lower section  42  and the upper section  44  are joined to become integral with each other to form the holder  40 , as shown in  FIG. 2 . When the holder  40  thus integrated is inserted into the mounting hole  30  in a predetermined posture with respect to the casing body  10 , the tongue piece  42   a  is elastically deformed inwardly in the radial direction to permit the insertion. After the tongue piece  42   a  has been inserted up to a position opposed to the engaging recess  30   b  of the mounting hole  30 , the tongue piece  42   a  is elastically recovered and engaged with the engaging recess  30   b , as shown in  FIG. 9 , and movement of the backward end part  42  in the withdrawing direction will be restricted.  
         [0067]     At the same time, the stepped part  44   a  of the upper section  44  comes into contact with the stepped part  30   a  of the mounting hole  30 , and movement of the upper section  44  in the inserting direction will be restricted. In this manner, the holder  40  is fixed to the casing body  10 . The rod-shaped antenna element  16  is arranged inside the holder  40  so as to be movable in the axial direction. In the withdrawal position, the power supply part  16   b  is brought into elastic contact with the elastic contact portion  50   a  of the power supply spring  50  to be electrically connected thereto. In the accommodated position, the power supply part  16   a  is brought into elastic contact with the elastic contact portion  50   a  to be electrically connected thereto. In this state, the tongue piece  50   b  of the power supply spring  50  is in a state opposed to the opening  30   e  which is formed in the mounting hole  30 , as shown in  FIG. 8 , and the power supply terminal  20  which is provided inside the casing body  10  and made of a leaf spring or the like is brought into elastic contact with the tongue piece  50   b  to be electrically connected thereto. As a result, the power supply parts  16   a ,  16   b  of the rod-shaped antenna element  16  are electrically connected appropriately to the electric circuit which is provided inside the casing body  10 , by way of the power supply spring  50  and the power supply terminal  20  in contact therewith.  
         [0068]     By the way, in order that the tongue piece  42   a  may be engaged with the engaging recess  30   b  of the mounting hole  30 , after the holder  40  has been inserted into the mounting hole  30 , the holder  40  must take the predetermined posture with respect to the mounting hole  30  around the axis in the inserting direction. In other words, the tongue piece  42   a  must be aligned with the engaging recess  30   b  in the axial direction.  
         [0069]     In this embodiment, as shown in  FIG. 7 , a chamfered portion  30   d  which has a slightly larger width than a width of the tongue piece  42   a  for enabling the tongue piece  42   a  to just pass through is provided on an edge of the mounting hole  30  which the tongue piece  42   a  comes into contact with, when the holder  40  is inserted into the mounting hole  30  in the predetermined posture around the axis, at the same axial position as the engaging recess  30   b.    
         [0070]     Moreover, a first vertical groove  30   e  which the stopper  42   e  can pass through when the holder  40  is inserted in the predetermined posture is formed in an axial direction on the inner peripheral wall of the mounting hole  30 . Further, a second vertical groove  30   f  which the stopper  42   e  can pass through, when the holder  40  is rotated for withdrawal inside the mounting hole  30  by 45 degree, for example, is formed in the axial direction on the inner peripheral wall of the mounting hole  30 . Still further, a circumferential groove  30   g  which the stopper  42   e  can pass through from the first vertical groove  30   e  to the second vertical groove  30   f , when the holder  40  is rotated around the axis from the inserting position where the tongue piece  42   a  is engaged with the engaging recess  30   b  is formed on the inner peripheral wall of the mounting hole  30 , as shown in  FIG. 10 .  
         [0071]     In this structure, when the holder  40  has been rotated inside the mounting hole  30  around the axis, by fitting an adequate tool into the grooves  44   c  for rotary operation of the holder  40 , the slanted face  42   b  of the tongue piece  42   a  comes contact with the circumferential edge of the engaging recess  30   b . Then, a component of a force is applied inwardly in the axial direction, and the tongue piece  42   a  is elastically deformed inwardly in the radial direction as shown in  FIG. 11 , to be disengaged from the engaging recess  30   b . At the same time, the stopper  42   e  passes through the circumferential groove  30   g , as shown in  FIG. 12 .  
         [0072]     When the holder  40  is rotated by a predetermined degree, the stopper  42   e  comes into alignment with the second vertical groove  30   f  thereby to restrict the rotation. It is apparent that in the state where the rotation is restricted, the tongue piece  42   a  is completely disengaged from the engaging recess  30   b . Consequently, the holder  40  can be withdrawn from the mounting hole  30  by making the stopper  42   e  pass through the second vertical groove  30   f , and exchange or so of the rod-shaped antenna element  16  can be easily conducted.  
         [0073]     In this embodiment, the holder  40  is divided in two along the dividing plane which is substantially perpendicular to the inserting direction, into the lower section  42  and the upper section  44 . However, the invention is not limited to this embodiment, but the holder  40  may be vertically divided in two along a dividing plane which is parallel to the inserting direction, so that the power supply spring  50  can be easily assembled to the holder  40 .  
         [0074]     Moreover, the mechanism for making the two divided parts integral into the holder  40  may have any structure. Further, the two divided parts may be appropriately joined by adhesion or welding instead of employing the mechanism. Alternatively, without dividing the holder in two, the holder may be integrally molded with the power supply spring  50 .  
         [0075]     Still further, the tongue piece  42   a  is not limited to the one in the above described embodiment in which the movement in the withdrawing direction is restricted by an end face of the free end of the tongue piece  42   a . The tongue piece  42   a  may be in any shape, provided that it can be elastically deformed to allow the insertion of the holder  40  into the mounting hole  30 , and elastically recovered after the holder  40  has been inserted up to the determined position, thereby to restrict the movement in the withdrawing direction. For example, the tongue piece may be extended downward in the inserting direction, and may be provided with a hook-shaped projection on an outer periphery of the free end, so that the movement in the withdrawing direction can be restricted by engaging this hook-shaped projection.  
         [0076]     Still further, the structure for disengaging the tongue piece  42   a  from the engaging recess  30   b  by rotating the holder  40  around the axis is not limited to the above described embodiment in which the tongue piece  42   a  is provided with the slanted face  42   b . The tongue piece  42   a  may be provided with a curved face instead of the slanted face  42   b . A face of the engaging recess  30   b  which the tongue piece  42   a  comes in contact with may be a slanted face or a curved face so as to exert a component of a force on the tongue piece  42   a  inwardly in the radial direction. It is apparent that both the tongue piece  42   a  and the contact face of the engaging recess  30   b  may be provided with the slanted face or the curved face.  
         [0077]     Furthermore, if the posture of the holder around the axis when it is withdrawn from the mounting hole  30  is not limited, the slanted face or the curved face may be provided not only on the contact face between the tongue piece  42  and the engaging recess  30   b  at one side in the circumferential direction, but also on the contact faces at both sides in the circumferential direction.  
         [0078]     Although the present invention has been shown and described with reference to specific preferred embodiments, various changes and modifications will be apparent to those skilled in the art from the teachings herein. Such changes and modifications as are obvious are deemed to come within the spirit, scope and contemplation of the invention as defined in the appended claims.