Abstract:
A structure for mounting an antenna device on a first side of a panel body is disclosed. A first fixation member includes a first end having a first width, a second end, and a slit connecting the first end and the second end. A protrusion is protruded from the antenna device and fitted into the first end of the first fixation member. A second fixation member is fitted into the second end of the first fixation member while being coupled with the protrusion in a screwing manner. The first width is smaller than a third width of an aperture formed in the panel body when the protrusion and the second fixation member are in a first screwing position, so that the protrusion, the first fixation member and the second fixation member are allowed to pass through the aperture from the first side to a second side. The slit is expanded such that the first end of the first fixation member is made to have a fourth width which is greater than the third width when the protrusion and the second fixation member are in a second screwing position where the protrusion and the second fixation member are closed to each other than the first screwing position.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to an antenna attaching apparatus for attaching an antenna base to the roof of a vehicle body.  
         [0002]     In the structure of a conventional antenna attaching apparatus for attaching an antenna device for a vehicle to the roof of a vehicle body, a mount screw protruded downward from the antenna base of the antenna device for a vehicle is inserted through a mount hole formed on the roof and a washer having a claw is fitted and inserted from below into the mount screw protruded downward from the roof, and furthermore, a nut is screwed and fixed. In order to enhance a workability, the washer having a claw and the nut are coupled and integrated so as to be relatively rotatable around a screw axis and not to be separated from each other in the direction of the screw axis. In order to enhance the workability, furthermore, Japanese Patent No. 2751146 has proposed a technique for provisionally fixing a nut to a mount screw through a washer having a claw. According to the proposed technique, the nut can be prevented from slipping from the mount screw even if an operator releases his or her hand from the nut after the provisional fixation. Consequently, the workability can be improved.  
         [0003]     In this structure, the nut can be prevented from slipping off even if an operator releases his or her hand from the nut after the nut is provisionally fixed to the mount screw, thereby improving the workability. However, it is necessary to carry out a working step of provisionally fixing the nut, from below a roof panel, to the mount screw inserted through the mount hole from above the roof panel.  
       SUMMARY OF THE INVENTION  
       [0004]     It is therefore an object of the invention to provide an antenna mounting structure capable of provisionally fixing an antenna base by an insertion through a mount hole of a roof panel from above, thereby further improving the workability.  
         [0005]     In order to achieve the above object, according to the invention, there is provided a structure for mounting an antenna device on a first side of a panel body, comprising:  
         [0006]     a first fixation member, comprising: 
        a tubular body, including a first end having a first width, a second end, and a slit connecting the first end and the second end; and     a plurality of elastic claw members, including a pair of claw members extended from the first end of the tubular body such that an interval between distal ends thereof is a second width which is larger than a third width of an aperture formed in the panel body;     a protrusion, protruded from the antenna device and fitted into the first end of the first fixation member;     a second fixation member, fitted into the second end of the first fixation member while being coupled with the protrusion in a screwing manner, wherein:     the first width is smaller than the third width when the protrusion and the second fixation member are in a first screwing position, so that the protrusion, the first fixation member and the second fixation member are allowed to pass through the aperture from the first side to a second side while flexing the pair of claw members inward;     the pair of claw members restore so as to prevent the protrusion, the first fixation member and the second fixation member from passing through the aperture from the second side to the first side; and     the slit is expanded such that the first end of the first fixation member is made to have a fourth width which is greater than the third width when the protrusion and the second fixation member are in a second screwing position where the protrusion and the second fixation member are closed to each other than the first screwing position.        
 
         [0014]     With this configuration, a provisional fixation state can be established by merely passing the protrusion, the first fixation member and the second fixation member which are coupled to each other through the aperture from the first side to the second side. The antenna device can be surely fixed on the panel body by screwing the second fixation member and the protrusion from this provisional fixation state. Since the operation for provisionally fixing the members on the panel body is simple and easy, it is suitable for mass production.  
         [0015]     Preferably, a wedge member is formed on at least one of the protrusion and the second fixation member, the wedge member fitted into the slit when the protrusion and the second fixation member are in the first screwing position. The wedge member is configured so as to expand the slit when the protrusion and the second fixation member are in the second screwing position.  
         [0016]     With this structure, not only the slit is reliably expanded, but also the first fixation member is prevented from being rotated in accordance with the screwing action of the second fixation member.  
         [0017]     Preferably, the first end of the second fixation member has a first diameter and the second end of the second fixation member has a second diameter which is larger than the first diameter.  
         [0018]     With this structure, the slit is automatically expanded in accordance with the screwing action of the second fixation member.  
         [0019]     Preferably, the aperture and the protrusion are shaped into rectangular.  
         [0020]     With this structure, the protrusion is prevented from being rotated in accordance with the screwing action of the second fixation member. Therefore, the posture of the antenna device can be properly maintained. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]     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:  
         [0022]      FIG. 1  is a perspective view showing an external appearance of an antenna device incorporating an antenna mounting structure according to a first embodiment of the invention;  
         [0023]      FIG. 2A  is a front view of an antenna base in the antenna mounting structure of  FIG. 1 ;  
         [0024]      FIG. 2B  is a side view of the antenna base of  FIG. 2A ;  
         [0025]      FIG. 2C  is a bottom view of the antenna base of  FIG. 2A ;  
         [0026]      FIG. 2D  is a section view taken along a line IID-IID in  FIG. 2C ;  
         [0027]      FIG. 2E  is a section view taken along a line IIE-IIE in  FIG. 2C ;  
         [0028]      FIG. 3A  is a front view of an engagement member in the antenna mounting structure of  FIG. 1 ;  
         [0029]      FIG. 3B  is a side view of the engagement member of  FIG. 3A ;  
         [0030]      FIG. 3C  is a rear view of the engagement member of  FIG. 3A ;  
         [0031]      FIG. 3D  is a bottom view of the engagement member of  FIG. 3A ;  
         [0032]      FIG. 3E  is a top view of the engagement member of  FIG. 3A ;  
         [0033]      FIG. 4A  is a side view of a mount screw in the antenna mounting structure of  FIG. 1 ;  
         [0034]      FIG. 4B  is a top view of the mount screw of  FIG. 4A ;  
         [0035]      FIG. 4C  is a bottom view of the mount screw of  FIG. 4A ;  
         [0036]      FIG. 5A  is a side view showing a state before the antenna base of  FIG. 2A  is provisionally fixed on a roof panel of a vehicle;  
         [0037]      FIG. 5B  is a bottom plan view showing the state of  FIG. 5A ;  
         [0038]      FIG. 6A  is a side view showing a state that the antenna base of  FIG. 2A  is provisionally fixed on the roof panel;  
         [0039]      FIG. 6B  is a bottom plan view showing the state of  FIG. 6A ;  
         [0040]      FIG. 7A  is a side view showing a state that the antenna base of  FIG. 2A  is plenarily fixed on the roof panel;  
         [0041]      FIG. 7B  is a bottom plan view showing the state of  FIG. 7A ;  
         [0042]      FIG. 7C  is a schematic top plan view showing the state of  FIG. 7A ;  
         [0043]      FIG. 8  is a side view of a mount screw in an antenna mounting structure according to a second embodiment of the invention;  
         [0044]      FIG. 9A  is a side view of a mount screw in an antenna mounting structure according to a third embodiment of the invention;  
         [0045]      FIG. 9B  is a bottom view of the mount screw of  FIG. 9A ;  
         [0046]      FIG. 10A  is a side view of a mount screw in an antenna mounting structure according to a fourth embodiment of the invention;  
         [0047]      FIG. 10B  is a side view of a bush in the antenna mounting structure of  FIG. 10A ;  
         [0048]      FIG. 11  is a side view of an engagement member and a mount screw in an antenna mounting structure according to a fifth embodiment of the invention;  
         [0049]      FIG. 12A  is a front view of an antenna base in an antenna mounting structure according to a sixth embodiment of the invention;  
         [0050]      FIG. 12B  is a side view of the antenna base of  FIG. 12A ;  
         [0051]      FIG. 13A  is a side view of a nut fitted with the antenna base of  FIG. 12A ;  
         [0052]      FIG. 13B  is a bottom view of the nut of  FIG. 13A ;  
         [0053]      FIG. 14  is a side view showing a state before the antenna base of  FIG. 12A  is provisionally fixed on a roof panel of a vehicle;  
         [0054]      FIG. 15A  is a side view showing a state that the antenna base of  FIG. 12A  is plenarily fixed on the roof panel; and  
         [0055]      FIG. 15B  is a bottom plan view showing the state of  FIG. 15A .  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0056]     Preferred embodiments of the invention will be described below in detail with reference to the accompanying drawings.  
         [0057]     According to a first embodiment of the invention, an antenna base  10  shown in  FIGS. 2A  to  2 E is fixed within a housing  12 . An amplifying circuit (not shown) is also accommodated in the housing  12 . Moreover, the base end of an antenna element  16  is fixed to the housing  12 .  
         [0058]     The tip of a mount screw  18  shown in  FIGS. 4A  to  4 C is screwed into the antenna base  10  from below as described later in detail. Moreover, an engagement member  20  shown in  FIGS. 3A  to  3 E is fitted with the mount screw  18 . Furthermore, a cable  22  such as a signal transmission line is led from the antenna base  10 . With such a structure, as shown in  FIG. 1 , the cable  22  is first inserted from above into a mount hole  24  provided on a roof panel of a vehicle body, and furthermore, the mount screw  18  and the engagement member  20  are inserted therein to carry out a provisional fixation.  
         [0059]     As shown in  FIGS. 2A  to  2 E, the antenna base  10  is formed of a conductive material, and has a lower face provided with a square protrusion  10   a.  A cylindrical projection  10   b  is provided on the center of the square protrusion  10   a.  A female screw  10   c  is threaded in a vertical direction at the center of cylindrical projection  10   b.  A wedge-shaped member  10   d  in which the lower end thereof is narrowed is formed so as to connect one corner of the square protrusion  10   a  and the peripheral face of the cylindrical projection  10   b . Notches  10   e  are formed at two corners of the square protrusion  10   a  which are adjacent to the corner at which the wedge-shaped member is provided. The notches  10   e  are for receiving provisional fixation claws  20   c  (described later in detail). A hole  10   f  penetrating the antenna base  10  in a vertical direction is formed in the vicinity of a corner of the square protrusion  10   a  which is opposite to the corner at which the wedge-shaped member is provided. The hole  10   f  is for allowing the cable  22  to pass therethrough.  
         [0060]     As shown in  FIGS. 3A  to  3 E, the engagement member  20  is formed by a conductive material plate and is shaped into a truncated cone in which a lower end diameter is less than an upper end diameter. The engagement member  20  is formed with a slit  20   a  so as to connect the upper end and the lower end thereof, so that the engagement member  20  is C-shaped in the plan view. At the upper end of the engagement member  20 , there are formed four engagement claws  20   b  projecting upward and two provisional fixation claws  20   c  projecting obliquely upward and outward. The distal ends of the provisional fixation claws  20   c  are situated upper and outer than the distal ends of the engagement claws  20   b.  A cutout  20   d  is formed for receiving the cable  22 .  
         [0061]     As shown in  FIGS. 4A  to  4 C, the mount screw  18  is formed of a conductive material. A screw body and a hexagonal head portion  18   a  are connected by a flange portion  18   b  and a truncated-conical portion  18   c.  The upper end of the truncated-conical portion  18   c  has an outer diameter which is slightly smaller than the inner diameter of the lower end of the engagement member  20  in an original state. The lower end of the truncated-conical portion  18   c  has an outer diameter which is larger than the inner diameter of the lower end of the engagement member  20  in an original state.  
         [0062]     The antenna base  10  is fixed to the housing  12  in advance and the rubber packing member  14  is attached to the lower portion of the antenna base  10 . The cable  22  is led from the inside of the housing  12  through the hole  10   f  of the antenna base  10 . The mount screw  18  is fitted and inserted into the engagement member  20  and the tip portion of the mount screw  18  is screwed into the female screw  10   c  of the antenna base  10  so that the mount screw  18  and the engagement member  20  are integrated with the antenna base  10 . The rubber packing member  14  is provided with a hole through which the square protrusion  10   a  of the antenna base  10  can penetrate.  
         [0063]     In such an integrated state, as shown in  FIGS. 1, 5A  and  5 B, the cable  22  is first inserted into the mount hole  24  provided on the roof panel to bring a condition in which the square protrusion  10   a  of the antenna base  10  faces the mount hole  24 . The mount hole  24  takes an almost square shape which is slightly larger than the square protrusion  10   a.  When the cable  22  is inserted into the mount hole  24  from above in the state of  FIG. 5 , the provisional fixation claws  20   c  are elastically deformed on two opposed corners of the mount hole  24 , thereby permitting the insertion. After a passage through the mount hole  24 , the provisional fixation claws  20   c  are elastically returned and tips thereof are positioned in the peripheral edge portion of the mount hole  24  so that a state shown in  FIGS. 6A and 6B  is brought. Here, the antenna base  10  is provisionally fixed to the mount hole  24  of the roof by the provisional fixation claws  20   c.    
         [0064]     When the mount screw  18  is screwed into the female screw  10   c  of the antenna base  10 , the tips of the provisional fixation claws  20   c  are first expanded over the back face of the roof panel. On the other hand, the wedge-shaped member  10   d  expands the slit  20   a  of the engagement member  20  from above by a wedge effect, and the truncated-conical portion  18   c  of the mount screw  18  also expands the slit  20   a  from below so that the diameter of the almost C shape of the engagement member  20  is more increased. As a result, as shown in  FIGS. 7A  to  7 C, the engagement claws  20   b  of the engagement member  20  are positioned in the peripheral edge portion of the mount hole  24  and cut into the back face of the roof panel by the strong fastening of the mount screw  18 . Accordingly, the antenna base  10  is plenarily fixed to the roof panel, while the electrical connection of the antenna base  10  and the roof panel is established by the engagement claws  20   b.    
         [0065]     With such a structure, a member obtained by integrating the engagement member  20  and the mount screw  18  with the antenna base  10  is simply inserted into the mount hole  24  from above the roof panel so that the antenna base  10  can be provisionally fixed to the roof panel. Thus, the provisional fixation work can easily be carried out. The mount screw  18  is rotated axially with the head portion  18   a  held by a tool from below the roof panel, and is thus screwed and fastened. Consequently, the engagement claws  20   b  of the engagement member  20  cut into the back face of the roof panel, and are thus fixed reliably and are electrically connected. In addition, since the mount hole  24  of the roof panel takes the almost square shape, the square protrusion  10   a  of the antenna base  10  is fixed to the roof in a constant posture.  
         [0066]      FIG. 8  shows a second embodiment of the invention. In this embodiment, a mount screw is constituted by two members including a bush  26  taking the shape of a truncated cone and a screw  28  having a hexagonal head portion. The bush  26  has an upper outer diameter which is slightly smaller than the lower inner diameter of the engagement member  20 , and a lower outer diameter set to be larger than the lower inner diameter of the engagement member  20  as in the first embodiment.  
         [0067]      FIGS. 9A and 9B  show a third embodiment of the invention. In this embodiment, the hexagonal head portion in the first embodiment is omitted. Instead, a bottomed hole  30   b  having a hexagonal cross section is formed on a bottom face of a truncated-conical portion  30   a  of a mount screw  30 . By inserting a hexagonal wrench into the bottomed hole  30   b,  it is possible to rotate the mount screw  30  to perform the screwing operation. When the screw  30  is screwed and fastened to fix the antenna base  10  to the roof, according to the omission of the head portion, a dimension L protruded from the back face of the roof panel shown in  FIG. 7  can be reduced effectively.  
         [0068]      FIGS. 10A and 10B  show a fourth embodiment of the invention. In this embodiment, an engagement member  32  is provided with a slit  32   a  having a tapered portion  32   b  formed at the lower end portion thereof such that a clearance is enlarged toward the lower side. A bush  34  has an upper outer diameter which is slightly smaller than a lower inner diameter of the engagement member  32  and a lower outer diameter which is set to be larger than the lower inner diameter of the engagement member  32 . Moreover, a flange portion  34   a  is provided on the lower end of the bush  34 , and a wedge-shaped member  34   b  to be inserted into the tapered portion  32   b  of the engagement member  32  to expand the clearance of the slit  32   a  is formed on an outer peripheral face of the bush  34 . Furthermore, there is provided a mount screw  36  for penetrating through the engagement member  32  and the bush  34  in a vertical direction. In this embodiment, the engagement member  32  can expand the clearance of the slit  32   a  by the wedge effect of the wedge-shaped member  34   b  of the bush  34 .  
         [0069]      FIG. 11  shows a fifth embodiment of the invention. In this embodiment, an engagement member  38  is provided with a truncated cone-shaped portion  38   a  in which an inner diameter is increased downward. An mount screw  40  is provided with a cylindrical member  40   a  having a slightly smaller outer diameter than the lower inner diameter of the truncated cone-shaped portion  38   a.  In this embodiment, the cylindrical member  40   a  abuts on an inner face of the truncated cone-shaped portion  38   a  by screwing and fastening the mount screw  40 , thereby expanding the engagement member  38 .  
         [0070]     Next, a sixth embodiment of the invention will be described with reference to  FIGS. 12A through 15B .  
         [0071]     As shown in  FIGS. 12A and 12B , an antenna base  50  in this embodiment is different from the antenna base  10  in the first embodiment in that a mount screw  50   a  is protruded downward from the antenna base  50  in place of the threading of the female screw  10   c.  A nut  52  shown in  FIGS. 13A and 13B  is constituted by a hexagonal head portion  52   a,  a flange portion  52   b  and a truncated-conical portion  52   c,  and a female screw  52   d  capable of being screwed into the mount screw  50   a  is threaded on a center of truncated-conical portion  52   c.  The truncated-conical portion  52   c  of the nut  52  has an upper outer diameter which is set to be smaller than a lower inner diameter of an engagement member  20  and a lower outer diameter which is set to be larger than the lower inner diameter of the engagement member  20 . In this embodiment, the same engagement member  20  as that in the first embodiment is used.  
         [0072]     The engagement member  20  and the nut  52  are assembled into the antenna base  50  and they are integrated with each other, and a cable  22  is inserted through a mount hole  24  of a roof panel from above as shown in  FIG. 14  and they are strongly pressed downward in this state. Consequently, provisional fixation claws  20   c  of the engagement member  20  are elastically deformed and are thus permitted to be inserted, and are elastically returned after a passage through the mount hole  24  so that an upward slip-off from the mount hole  24  can be prevented to establish a provisional fixation state. When the nut  52  protruded downward is strongly fastened, the diameter of the engagement member  20  is greatly changed so that engagement claws  20   b  cut into the peripheral edge portion of the mount hole  24  on the back side of the roof panel as shown in  FIG. 15 . The engagement member  20  is thus fixed on the roof panel while establishing electrical connection therebetween.  
         [0073]     Also in this embodiment, various mechanisms for expanding the slit of the engagement member  20  as explained in the fourth and fifth embodiments may be properly adopted. Further, variations as explained in the second and third embodiments may be adopted. That is, the head portion  52   a  of the nut  52  may be omitted and a hexagonal bottomed hole may be provided. Further, the head portion  52   a  and the truncated-conical portion  52   c  in the nut  52  may be provided as separate members.  
         [0074]     In the above embodiments, two provisional fixation claws  20   c  are provided. However, the number of the provisional fixation claws  20   c  may be more than two. In the above embodiments, the mount hole  24  formed on the roof panel is shaped into square. However, the shape of the mount hole  24  may be circular or oval. In this case, the shape of the protrusion  10   a  of the antenna base  10  is properly changed so as to correspond to the shape of the mount hole  24 . In the above embodiments, the engagement claws  20   b  are cut into the back face of the roof panel to establish the electric connection therebetween. However, if it is not necessary to establish the electric connection, or any other member for establish the electric connection is provided, the engagement member  20  may not be a conductive member. In this case, the engagement member  20  may be made of any materials capable of being deformed elastically or plastically.  
         [0075]     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.