TREA

GPS receiving antenna with ensured magnet attraction and firm mounting of antenna body

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Information

  • Patent Grant
  • 6384791
  • Patent Number
    6,384,791
  • Date Filed
    Wednesday, April 18, 2001
    23 years ago
  • Date Issued
    Tuesday, May 7, 2002
    22 years ago
Information
Abstract
A GPS receiving antenna is disclosed wherein a hole for communication between a recess portion and a receptacle portion is formed in a bottom wall with the recess portion formed therein and an adhesive is applied into the hole to bond an antenna body and a magnet with each other. Therefore, the adhesive does not protrude to the exterior of the recess portion, so that the appearance of the GPS receiving antenna is improved and a surface attraction of the magnet is ensured, thus ensuring a more positive mounting of the antenna than in the prior art.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to a GPS receiving antenna attached to the outside of a moving object such as a ship or an automobile to receive a radio wave generated from a GPS (Global Positioning System) satellite.




2. Description of the Prior Art




The configuration of a conventional GPS receiving antenna will now be described with reference to

FIGS. 4 and 5

. A box-shaped upper case


21


, which is formed by molding a synthetic resin, comprises an upper wall


21




a


, side walls


21




b


extending from four sides of the upper wall


21




a


, a receptacle portion


21




c


surrounded by the upper wall


21




a


and side walls


21




b


and whose underside is open, and stepped portions


21




d


formed as recesses in and along the side walls


21




b.






A box-shaped lower case


22


, which is formed by molding a synthetic resin, comprises a bottom wall


22




a


, side walls


22




b


extending from four sides of the bottom wall


22




a


, a receptacle portion


22




c


surrounded by the bottom wall


22




a


and side walls


22




b


and whose upper side is open, stepped portions


22




d


formed as projections in and along the side walls


22




b


, and a pair of recess portions


22




e


each formed in the shape of a rectangular parallelepiped in the underside of the bottom wall


22




a.






The upper and lower cases


21


,


22


are combined together so that the receptacle portions


21




c


and


22




c


are opposed to each other and are mounted together by a suitable means.




As a result, a single receptacle portion is formed by the receptacle portions


21




c


and


22




c


and the stepped portions


21




d


and


22




d


are fitted together, with a packing being mounted in each of the thus-fitted portion to seal the interiors of the receptacle portions


21




c


and


22




c


. Thus, there is provided a waterproof configuration against the entry of water, etc.




An antenna body


24


is made up of: an earth plate


25


; an antenna element


26


for receiving a radio wave from a GPS satellite, the antenna element


26


being provided on the surface side of the earth plate


25


; a dielectric substrate


27


provided on the back side of the earth plate


25


, with electric components (not shown) such as resistors, capacitors and IC parts being mounted on the substrate


27


; and a shielding case


28


for shielding the dielectric substrate


27


electrically.




The antenna body


24


thus constructed is accommodated within the sealed receptacle portions


21




c


and


22




c


in such a manner that the shielding case


28


lies on the bottom wall


22




a


side of the lower case


22


.




A waterproofing sleeve


30


is fitted on an outer surface of a coaxial cable


29


and the coaxial cable


29


is mounted in a state such that the sleeve


30


is sandwiched between the upper and lower cases


21


,


22


. The coaxial cable


29


is connected to the dielectric substrate


27


and is drawn out to the exterior.




A pair of magnets


31


, each in the shape of a rectangular parallelepiped, are received respectively within the recess portions


22




e


of the lower case


22


and are attached to the lower case


22


with an adhesive


32


applied into the recess portions


22




e.






By utilizing the magnetism of the magnets


31


, the GPS receiving antenna thus constructed is attached by attraction to the outside of a moving object such as a ship or an automobile (the roof of an automobile, for example).




In the conventional GPS receiving antenna, since the adhesive


32


for mounting the magnets


31


is applied into the recess portions


22




e


of the lower case


22


, the adhesive


32


applied to upper surfaces of the recess portions


22




e


is forced out to the exterior of the recess portions


22


e by being pushed with the magnets


31


, thus giving rise to the problem that not only the commercial value is impaired but also surface-attraction of the magnets


31


is obstructed by the thus-protruded adhesive


32


, resulting in the mounting of the GPS receiving antenna becoming unstable.




Moreover, since the antenna body


24


is merely accommodated within the receptacle portions


21




c


and


22




c


, the mounting thereof is unstable and there occurs wobbling.




SUMMARY OF THE INVENTION




Accordingly, it is an object of the present invention to provide a GPS receiving antenna free of adhesive protrusion, capable of ensuring magnet attraction, and with an antenna body mounted firmly.




According to a first aspect of the present invention, there is provided a GPS receiving antenna comprising upper and lower cases; an antenna body received in a receptacle portion formed by the upper and lower cases; and a magnet received in a recess portion formed in a lower surface of a bottom wall of the lower case and bonded to the lower case with an adhesive, wherein a hole for communication between the recess portion and the receptacle portion is formed in the bottom wall in which the recess portion is formed, and the adhesive is applied into the hole to bond the antenna body and the magnet with each other.




According to a second aspect of the present invention there is provided, in combination with the above first aspect, a GPS receiving antenna wherein a depression is formed in the lower surface of the bottom wall opposed to the magnet so that the adhesive is present in the depression.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a sectional view of a principal portion of GPS receiving antenna according to the first embodiment of the present invention;





FIG. 2

is a bottom view thereof,





FIG. 3

is a sectional view of a principal portion of a GPS receiving antenna according to the second embodiment of the present invention;





FIG. 4

is a sectional view of a principal portion of a conventional GPS receiving antenna; and





FIG. 5

is a bottom view thereof.











DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS




A GPS receiving antenna according to the first embodiment of the present invention will be described below with reference to

FIGS. 1 and 2

.




An upper case


1


, which is formed in a box shape by molding a synthetic resin, comprises an upper wall


1




a


, side walls


1




b


extending from four sides of the upper wall


1




a


, a receptacle portion


1




c


surrounded by the upper wall


1




a


and the side walls


1




b


and whose underside is open, and stepped portions


1




d


formed as recesses in and along the side walls


1




b.






A lower case


2


, which is formed in a box shape by molding a synthetic resin, comprises a bottom wall


2




a


, side walls


2




b


extending from four sides of the bottom wall


2




a


, a receptacle portion


2




c


surrounded by the bottom wall


2




a


and the side walls


2




b


and whose upper side is open, stepped portions


2




d


formed as projections in and along the side walls


2




b


, a pair of recess portions


2




e


each formed in the shape of a rectangular parallelepiped in a lower surface of the bottom wall


2




a


, holes


2




f


formed in the bottom wall


2




a


to provide communication between the receptacle portion


2




c


and the recess portions


2




e


, and depressions


2




g


formed respectively in upper surfaces of the recess portions


2




e


. The upper and lower cases


1


,


2


are combined so that the receptacle portions


1




c


and


2




c


are opposed to each other, and are mounted together by a suitable means.




At this time, a single receptacle portion is formed by the receptacle portions


1




c


and


2




c


and the stepped portions


1




d


and


2




d


are fitted together. A packing


3


is disposed in the thus-fitted portion to seal the interiors of the receptacle portions


1




c


and


2




c


. In this way there is provided a waterproof structure against the entry of water, etc.




An antenna body


4


is made up of an earth plate


5


, an antenna element


6


provided on the surface side of the earth plate


5


to receive a radio wave from a GPS satellite, a dielectric substrate


7


disposed on the back side of the earth plate


5


and with electric components (not shown) such as resistors, capacitors and IC parts mounted thereon, and a shielding case


8


for shielding the dielectric substrate


7


electrically.




The antenna body


4


is received within the sealed receptacle portions


1




c


and


2




c


in such a manner that the shield case


8


lies on the bottom wall


2




a


side of the lower case


2


.




A waterproofing sleeve


10


is fitted on an outer surface of a coaxial cable


9


. The coaxial cable


9


is mounted in a sandwiched state of the sleeve


10


between the upper and lower cases


1


,


2


and it is connected to the dielectric substrate


7


and is drawn out to the exterior.




A pair of magnets


11


each in the shape of a rectangular parallelepiped are received respectively within the recess portions


2




e


of the lower case


2


and an adhesive


12


is applied into the depressions


2




g


and holes


2




f


formed in the recess portions


2




e


. With the adhesive


12


, the magnets


11


and the shield case


8


as the antenna body


4


are bonded together and secured to the lower case


2


.




In this case, since the adhesive


12


is present in the depressions


2




g


, the magnets


11


are bonded more firmly to the lower case


2


.




Although in this first embodiment the depressions


2




g


are formed in an inclined state, the depressions


2




g


may be formed with a stepped portion as a substituted for such an inclined portion.




By utilizing the magnetism of the magnets


11


the GPS receiving antenna constructed as above is attached attractively to the outside of a moving object such as a ship or an automobile (the roof of an automobile, for example).




Referring now to

FIG. 3

, there is illustrated a GPS receiving antenna according to the second embodiment of the present invention, in which the depressions


2




g


used in the previous first embodiment are not formed, but only holes


2




f


are formed. Other components in this second embodiment are the same as in the first embodiment, so will be identified by the same reference numerals as in the first embodiment and explanations thereof will here be omitted.




In the GPS receiving antenna according to the present invention, as set forth above, since holes


2




f


for communication between the recess portions


2




e


and the receptacle portion


2




c


are formed in the bottom wall


2




a


which defines the recess portions


2




e


and the antenna body


4


and the magnet


11


are bonded together through an adhesive applied into the holes


2




f


, the adhesive


12


does not protrude to the exterior of the recess portions


2




e


. Consequently, the appearance of the GPS receiving antenna is improved and a surface attraction of the magnets


11


is ensured, thus ensuring a more positive mounting of the antenna than in the prior art.




Further, since the depressions


2




g


are formed in the lower surface of the bottom wall


2




g


opposed to the magnets


11


and the adhesive


12


is present in the depressions


2




g


, the magnets


11


can be bonded to the case


2


more firmly.



Claims
  • 1. A GPS receiving antenna comprising:an upper case and a lower case; an antenna body received in a receptacle portion formed by the upper and lower cases; and a magnet received in a recess portion formed in a lower surface of a bottom wall of the lower case and bonded to the lower case with an adhesive, wherein a hole for communication between the recess portion and the receptacle portion is formed in the bottom wall in which the recess portion is formed, and the adhesive is applied into the hole to bond the antenna body and the magnet with each other.
  • 2. A GPS receiving antenna according to claim 1, wherein a depression is formed in the lower surface of the bottom wall opposed to the magnet so that the adhesive is present in the depression.
Priority Claims (1)
Number Date Country Kind
2000-126241 Apr 2000 JP
US Referenced Citations (6)
Number Name Date Kind
5585809 Yajima et al. Dec 1996 A
5706015 Chen et al. Jan 1998 A
5757327 Yajima et al. May 1998 A
5900840 Yajima May 1999 A
5943018 Miller Aug 1999 A
6023245 Gomez et al. Feb 2000 A
Foreign Referenced Citations (4)
Number Date Country
08148916 Jun 1996 JP
08148932 Jun 1996 JP
10135720 Jun 1998 JP
HEI 10-190329 Jul 1998 JP