Patent Application
20060056911
This application claims priority to prior Japanese patent application JP 2004-264547, the disclosure of which is incorporated herein by reference.
This invention relates to a fixing device for fixing an object to a fixing plate by the use of a screw member and to an antenna apparatus using the fixing device.
Recently, a digital radio receiver adapted to receive a satellite wave or a ground wave so as to listen to digital radio broadcasting is put into practical use. The digital radio receiver is mounted to a mobile station. Specifically, the digital radio receiver is adapted to receive a radio wave having a frequency of about 2.3 GHz as a reception wave. The reception wavelength (resonance wavelength) λ is equal to about 128.3 mm. Thus, the digital radio receiver is capable of listening to the digital radio broadcasting.
Thus, the digital radio receiver is a radio receiver adapted to listen to mobile broadcasting. The ground wave is obtained by slightly shifting the frequency of the satellite wave after the satellite wave is received by a ground station, and is re-transmitted with linear polarization.
An antenna for receiving the radio wave is disposed outside the mobile station. In case where the digital radio receiver is mounted to an automobile, the antenna is generally attached to a roof plate of the automobile.
For example, Japanese Utility Model Application Publication (JP-U) No. H5-88007 discloses a mounting structure of an automobile antenna, in which a case containing the antenna can be attached to a mounting member at a desired angle.
In the above-mentioned mounting structure, a cable can be extracted from a cable fitting groove formed on a lower surface of the case to the outside at any desired angle. The mounting member is provided with a fitting hole having four convex portions protruding from a center space, and a plurality of mounting portions formed on one side thereof as bent portions.
An antenna is fixed to the roof plate of the automobile by the screw. Generally, installation's work of the antenna is done by one worker. In order to facilitate the installation's work, the antenna manufacturer delivers the antenna to the vehicle manufacturer in a condition where the mounting member is temporarily attached to the antenna with the screw.
However, the mounting member might accidentally be released from the antenna caused by vibration during transportation and so on. This is because the mounting member is not tightly fixed to the antenna.
It is therefore an object of this invention to provide a fixing device for fixing an object, in which a fixing member corresponding to the above-mentioned mounting member is prevented from being accidentally released during transportation of the object.
It is an another object of this invention to provide an antenna apparatus, in which retightening of the screw member can readily be carried out.
Other objects of the present invention will become clear as the description proceeds.
According to one aspect of the invention, there is provided a fixing device for fixing an object to a fixing plate having a fixing hole. The fixing device comprises a fixing portion formed on the object, a first screw member connected to the fixing portion and having a first threaded portion, a second screw member having a second threaded portion capable of being screwed with the first threaded portion, a screw lock substance added to the threaded portion, and a fixing member coupled over the fixing portion, the fixing member comprising a bottom plate portion having a through hole allowing a second threaded portion to pass therethrough, the bottom plate portion having an outer dimension smaller than a fixing hole; and a plurality of spring portions extending from the bottom plate portion in one direction, the second threaded portion being screwed in the first threaded portion through the screw lock substance.
Now, with reference to the drawing, description will be made of a fixing device for fixing an object to a fixing plate according to this invention. In this embodiment, consideration will be made about an automobile antenna apparatus (hereinafter simply referred to as an antenna apparatus) by way of example.
Referring to
The case 11 contains an antenna element (not shown). The fixing portion 13 is formed at an approximate center of a bottom surface 11f of the case 11 and protrudes downward from the bottom surface 11f. The fixing portion 13 has a female screw (first screw member) 14 formed inside. The fixing portion 13 is covered with a bracket (fixing member) 15. The bracket 15 is fixed to the fixing portion 13 by screw engagement between the female screw 14 and a male screw (second screw member) 16.
On the bottom surface 11f of the case 11, a locator pin 17 is formed at a position deviated from the center of the bottom surface 11f and protrudes downward from the bottom surface 11f. A cable 20 is led into the case 11. The cable 20 has one end connected to the antenna element (not shown) contained in the case 11. The cable 20 extending outside the case 11 has the other end connected to a plug 22 also shown in
The through hole 15a allows the threaded cut portion 16b of the male screw 16 to pass therethrough from the outside of the bottom plate portion 15b. The spring portions 15c extend from the bottom plate portion 15b upward (in one direction) in such a manner that a space between the spring portions 15c is widened upward.
Each of the spring portions 15c has a generally arc-shaped surface generally concentric with the through hole 15a. Each of the spring portions 15c has a pair of lateral sides 15d with a pair of guide portions 15e formed at intermediate portions thereof. The lateral sides 15d of the spring portions 15c are faced to each other in a circumferential direction with gaps left between every confronting ones. The guide portions 15e protrude from the lateral sides 15d towards the gaps between the lateral sides 15d.
Each of the guide portions 15e has a forward edge bent inward from the lateral side 15d. The guide portions 15e serve as a guide when the bracket 15 is temporarily fixed to the fixing portion 13. Further, the guide portions 15e serve to prevent the spring portions 15c from being excessively widened when the male screw 16 is tightened in order to fix the antenna apparatus 10. As shown in
The bottom plate portion 15b has an outer dimension smaller than the fixing hole 41. In other words, the fixing hole 41 allows the bottom plate portion 15b to easily pass therethrough. On the other hand, an outer dimension of the bracket 15 at an upper part of the spring portions 15c is greater than the fixing hole 41. In other words, the fixing hole 41 does not allow the upper part of the spring portions 15c to pass therethrough.
Each of the spring portions 15c has a pair of cut-away portions 15f. Each of the cut-away portions 15f is formed by generally linearly cutting a part of the spring portion 15c between the bottom plate portion 15b and a lower end of the guide portion 15e and from the lateral side 15d towards the arc-shaped surface of the spring portion 15c. By forming the cut-away portions 15f, the bracket 15 is provided with step portions 15h at the intermediate portions of the lateral sides 15d of the spring portions 15c. The step portions 15h are substantially Incline to the bottom plate portion 15b.
The antenna apparatus has a positioning hole 42 formed on the roof plate 40 in correspondence to the locator pin 17. In order to mount the antenna apparatus 10 to the roof plate 40, the fixing portion 13 is faced to and inserted into the fixing hole 41 and the locator pin 17 is faced to and inserted into the positioning hole 42. Thus, the antenna apparatus 10 is oriented in a predetermined direction.
As illustrated in
The one end 21 of the cable 20 is held by a cable bushing 30 inside the case 11. The plug 22 is attached to the other end of the cable 20.
When the antenna apparatus 10 is fixed to the roof plate 40, the cable 20 is connected to a receiver (not shown) disposed inside the automobile. The plug 22 is connected to the receiver.
In order to fix the antenna apparatus 10 to the roof plate 40, the following operation is required. At first, the fixing hole 41 corresponding to the fixing portion 13 of the antenna apparatus 10 is formed on the roof plate 40, as illustrated in
Before the fixing portion 13 is inserted into the fixing hole 41, the bracket 15 is arranged to face an outer surface of the fixing portion 13. By engaging the male screw 16 with the female screw 14, the bracket 15 is coupled and temporarily fixed to the fixing portion 13.
Then, the fixing portion 13 and the bracket 15 are inserted into the fixing hole 41. A part of the roof plate 40 is interposed between the bottom surface of the case 11 and the bracket 15 so that the antenna apparatus 10 is temporarily fixed to the roof plate 40.
When the bracket 15 is inserted into the fixing hole 41, the spring portions 15c of the bracket 15 are pressed by an inner edge of the fixing hole 41 to be displaced and inserted into the fixing hole 41. After the bracket 15 is inserted through the fixing hole 41 into the inside of the roof plate 40, a part of the roof plate 40 is clamped by the case 11 and upper ends of the spring portions 15c. At this time, the bracket 15 serves as a clip.
Thereafter, as illustrated in
As described above, the antenna apparatus 10 is oriented in the predetermined direction. This is because the cable 20 is extracted in a specific direction. In addition, it is necessary to suppress an influence of a wind pressure and to avoid intrusion of wind and rain due to mismatching in shape between the roof plate 40 and the bottom surface of the case 11 of the antenna apparatus 10.
Referring to
In the modification, a screw lock substance 18 is adhered to a surface of the threaded cut portion 16b of the male screw 16. More particularly, the screw lock substance 18 is made of an adhesive consisting of the resin and is applied to a whole of an end surface and of a peripheral surface of the threaded cut portion 16b of the male screw 16.
For example, as screw lock substance 18, it uses an acrylic resin. Incidentally, screw lock substance 18 may use the self Toru arrival tape which was wound around the threaded cut portion 16b instead of the adhesive. As the self Toru arrival tape, the acetic acid vinyl tape can be adopted.
With this structure, the bracket 15 is prevented from being loosened, even if the antenna 10 is received with a vibration during transportation of the antenna 10. This is because the male screw 16 is tightly held by the female screw 14 through the screw lock substance 18.
However, it is readily possible to fasten the male screw 16 inside the compartment for retightening thereof. This is because the screw lock substance 18 is destroyed or broken by rotation of the male screw 16. That is, the screw lock substance 18 does not obstruct an operation of retightening the male screw 16.
While this invention has thus far been described in connection with the preferred embodiment thereof, it will be readily possible for those skilled in the art to put this invention into practice in various other manners without departing from the scope set forth in the appended claims.
For example, in the form of the above mentioned implementation, it raised as the screw lock substance, using adhesive and a self Toru arrival tape as an example and it was explained but it may use the other material of course.
Also, for example, in the foregoing, consideration has been made of the case where the antenna apparatus is mounted to the roof plate of the automobile. It is noted that this invention is also applicable to any object other than the antenna apparatus and to any fixing plate other than the roof plate of the automobile. In the foregoing embodiment, the bracket produced by bending a metal plate by pressing is used as the fixing member. Alternatively, the fixing member may be produced by molding a resin material. As far as the spring portions have elasticity, the fixing member may be made of any other appropriate material.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2004-264547 | Sep 2004 | JP | national |
