JPH09307324A - Retractable rod antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a silencing resin sleeve from being damaged and to ensure an excellent operability in retractable motion by providing a guard to part or an entire circumference of a tip of a spring member of the retractable rod antenna and adopting a structure that the guard is in press contact with a resin sleeve provided in the rod in the case of extending the antenna. SOLUTION: This retractable rod antenna is structured such that a small diameter rod 2 is contained within a large diameter rod 1 and this structure is formed in multi-stages. A spring member 4 is mounted around a base end of the small diameter rod 2 and in order to prevent a metallic noise sound caused by the spring member 4 colliding with an upper end of the large diameter rod 1 when the antenna is fully extended, a resin sleeve 3 is provided to the upper end of the large diameter rod 1. The spring member 4 whose tongue 4a at its side face is in contact with the inner face of the large diameter rod 1 ensures electric contact between the rods. Furthermore, a guard 4b is formed to a tip of the spring member 4 to avoid the small diameter rod 2 from coming off and the resin sleeve 3 from being damaged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telescopic rod antenna mounted on a vehicle such as an automobile.

[0002]

2. Description of the Related Art In an antenna mounted on a vehicle such as an automobile, a structure for accommodating a cylindrical small diameter rod is also formed inside a cylindrical large diameter rod in multiple stages, and the small diameter rod is inserted from the upper end of the large diameter rod. An extendable rod antenna having a structure in which it can be expanded or contracted by pulling out a part of a small diameter rod in a large diameter rod is generally used. This telescopic rod antenna has a base end portion on the outer circumference of the small diameter rod for electrically connecting the large diameter rod and the small diameter rod or for preventing the small diameter rod from coming off from the upper end of the large diameter rod. A metal spring member is mounted in the vicinity.

FIG. 3 is a partial sectional view of a conventional telescopic rod antenna to which the above spring member is attached, and FIG. 4 is a perspective view of the spring member. Small diameter rod 2 inside large diameter rod 1
Is housed, and a spring member 30 is attached near the base end of the small diameter rod 2. The spring member 30 is a thin cylindrical member made of metal, and usually has a split and is elastically mounted on the outer periphery of the small diameter rod end. Then, a tongue piece portion 30a protruding outward is formed on the side surface thereof, and the tongue piece portion 30a contacts the inner surface of the large-diameter rod 1 to secure electrical contact between the large-diameter rod and the small-diameter rod. There is. In addition, in this type of telescopic rod antenna, a resin sleeve is provided on the upper end of the large-diameter rod 1 in order to prevent metallic noise generated when the upper end of the spring member 30 collides with the upper end of the large-diameter rod when the antenna is fully extended. 3 is provided.

[0004]

In the conventional telescopic rod antenna described above, there is a problem that the tip of the thin spring member 30 bites into the resin sleeve 3 and damages the resin sleeve 3 when the antenna is fully extended. In addition, depending on the case, there is a problem that the tip end portion of the spring member 30 is sandwiched between the resin sleeve 3 and the outer circumference of the small diameter rod 2 to deteriorate the operability when the antenna is housed. As a solution to this problem, a metal collar is interposed between the tip of the spring member 30 and the resin sleeve 3 (see Japanese Utility Model Laid-Open No. 61-70406), or the tip of the spring member 30 has a wavy shape. Proposals have been made such as those that have been deformed (see Japanese Utility Model Publication No. 5-14562). However, in the former proposal, there is a problem that the number of parts increases and the cost increases because a separate metal collar is required, and in the latter proposal, it is arranged at a small interval between the large diameter rod inner diameter and the small diameter rod outer diameter. To process the tip of the spring member into a wavy shape with a complicated shape,
There is a problem that it is very difficult to process because it is necessary to ensure accuracy. Further, in the latter proposal, although the contact area is slightly increased by making the end portion wavy, the point that the thin spring member tip directly abuts the resin sleeve is no different from the conventional one, and a large force is applied. In this case, the tip of the spring member 30 may still bite into the resin sleeve 3 and damage the resin sleeve.

The present invention has been proposed in order to cope with the above situation, and does not require high-precision machining, and at a low cost, the tip of the spring member bites into the resin sleeve or the spring member. An object of the present invention is to provide a telescopic rod antenna that reliably solves the problem that the tip portion is sandwiched between the resin sleeve and the outer circumference of the small diameter rod.

[0006]

In order to achieve the above object, the present invention has a structure in which a small-diameter rod is housed inside a large-diameter rod in multiple stages, and a resin is provided at the tip of the large-diameter rod. A sleeve is provided and a spring member is provided on the outer circumference of the base end of the small diameter rod, and the structure is made flexible by pulling out the small diameter rod from the upper end of the large diameter rod or by storing a part of the small diameter rod in the large diameter rod. In the telescopic rod antenna, the spring member is characterized in that a flange portion is provided on the entire circumference or a part of the tip end portion that comes into contact with the resin sleeve when the antenna is extended.

[0007]

By providing the flange at the tip of the spring member, the flange comes into contact with the resin sleeve provided at the tip of the large diameter rod at the extension limit when the antenna is extended. Therefore, the contact area where the spring member comes into contact with the resin portion is significantly increased by the receiving surface of the flange portion, and even if a large force pulling the antenna acts, the small-diameter rod is securely prevented from coming off, and moreover, It is possible to completely prevent the resin sleeve from being damaged by the tip of the spring member cutting into the resin sleeve. The flange portion can be easily formed by intermittently cutting the tip end portion of the spring member to form unevenness, and bending the protrusion outward, without requiring complicated and highly accurate processing, Also,
Low cost because no increase in the number of parts.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partial cross-sectional view of the telescopic rod antenna of the present invention, and FIG. 2 is a perspective view of the spring member of the present invention (note that the same parts as in the prior art are designated by the same reference numerals). Similar to the conventional example, the small-diameter rod 2 is housed inside the large-diameter rod 1, and this structure is formed in multiple stages to form a telescopic rod antenna. The spring member 4 is attached near the base end of the small-diameter rod 2, and when the antenna is fully extended, the upper end of the spring member 4 collides with the upper end of the large-diameter rod to prevent a metallic sound. A resin sleeve 3 is provided on the upper end of the rod 1.

The spring member 4 can be formed by cylindrically processing a thin plate made of a highly elastic metal material, and at this time, it can be elastically mounted on the outer circumference of the small-diameter rod end by splitting 4c. A tongue piece 4a is formed on the side surface of the spring member 4, and the tongue piece 4a contacts the inner surface of the large-diameter rod 1 to ensure electrical contact between the large-diameter rod and the small-diameter rod.

A flange portion 4b is formed at the tip of the spring member 4. When forming the spring member from the flat plate, the flange portion 4b can be formed by cutting the side to be the tip into unevenness, cylindrically processing, and then bending outward. As shown in FIG. 1, the spring member 4 provided with the collar portion 4b is attached to the small diameter rod 2
The flange 4b comes into contact with the rear surface of the resin sleeve 3 at the extension limit of each stage of the antenna. As a result, even if a large force for pulling the antenna acts, the small diameter rod 1 is prevented from coming off with certainty by the stopper action of the collar portion 4b, and the tip of the spring member 4 has a resin sleeve due to the wide contact area of the collar portion 4b. It is possible to completely prevent the resin sleeve 3 from being bitten into and damaging the resin sleeve 3.

Here, the spring member of the telescopic rod antenna according to the present invention can be used at all connecting points of the large diameter rod and the small diameter rod. Further, the method of mounting the spring member on the end portion of the small diameter rod may be not only the elastic mounting in which the above-mentioned split is formed, but also other mounting methods such as bonding and welding.

[0012]

Since the present invention is configured as described above,
The following effects are obtained. (1) It is possible to reliably prevent the small-diameter rod from coming off due to the stopper action of the flange portion of the spring member. (2) By providing the flange portion having a large contact area with the resin sleeve at the tip of the spring member, the tip of the spring portion does not bite into the resin sleeve at the extension limit of each step of the antenna, and the damage of the resin sleeve can be prevented. At the same time, it is possible to prevent the tip of the spring member from being inserted into the gap between the resin sleeve and the outer circumference of the small diameter rod, so that good operability can be secured during expansion and contraction. (3) The brim provided at the tip of the spring member has a simple structure and does not require complicated and high-precision processing. Therefore, the brim can be easily formed, and the number of parts does not increase. The cost.

[Brief description of drawings]

FIG. 1 is a partial sectional view of a telescopic rod antenna of the present invention.

FIG. 2 is a perspective view of a spring member according to the present invention.

FIG. 3 is a partial sectional view of a conventional telescopic rod antenna.

FIG. 4 is a perspective view of a spring member in a conventional telescopic rod antenna.

[Explanation of symbols]

 1 Large diameter rod 2 Small diameter rod 3 Resin sleeve 4 Spring member 4a Tongue part 4b Collar part 4c Split

Claims (2)

[Claims] 1. A structure for accommodating a small-diameter rod inside a large-diameter rod is formed in multiple stages, a resin sleeve is provided at the tip of the large-diameter rod, and a spring member is provided on the outer periphery of the base end of the small-diameter rod. In the telescopic rod antenna having a structure in which the small-diameter rod is pulled out from the upper end of the large-diameter rod or a part of the small-diameter rod is housed in the large-diameter rod, the spring member is made of the resin A telescopic rod antenna, characterized in that a brim portion is provided on the entire circumference or a part of the tip end portion that abuts on the sleeve. 2. The telescopic rod antenna according to claim 1, wherein the collar portion is formed by bending a protrusion formed by cutting out a tip of a spring member intermittently to the outside.