JPH036014Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

The present invention relates to a helical antenna in which a bendable coil element is covered with an elastic synthetic resin or rubber tube, and the coil element and tube are attached to a base metal fitting.

[Conventional technology]

A conventional helical antenna as described above will be explained with reference to FIGS. 4 to 6. In this helical antenna, a freely bendable coil element 1 is covered with a tube 2 made of elastic synthetic resin or rubber such as vinyl chloride, and the lower end of the coil element 1 is fitted into the small diameter part 3a of the upper end of a base metal fitting 3. The lower end portion of the tube 2 extending downward from the lower end of the coil element 1 is press-fitted into the tapered upper portion 3b of the base metal fitting 3. Further, a cap 4 is fitted and fixed to the upper end of the tube 2, and a mounting screw portion 3c is formed at the lower part of the base metal fitting 3 to attach the antenna to the equipment to be used.

[Problem that the invention attempts to solve]

In the conventional helical antenna like the one described above, the tube 2 is press-fitted into the upper part 3b of the base metal fitting 3, and the upper part 3b is provided with a taper that has a smaller diameter on the lower side to prevent the tube 2 from coming off. However, since the tube 2 is press-fitted, its pull-out strength and torsional strength in the direction of rotation are low, and although the tube 2 expands in a high-temperature atmosphere, the stress due to the press-fit is added to it, so it cannot return to room temperature again. However, there were problems in that the material did not return to its original state, the retention function due to press-fitting was reduced, and the high temperature resistance was insufficient, so that it could not be used for a long period of time.

[Means to solve the problem]

The present invention was developed to solve the above-mentioned problems, and it increases the torsional strength of the tube in the direction of pull-out and rotation, and improves the high temperature resistance of these strengths, so it can be used for a long time. The purpose is to provide a helical antenna that can be used stably over time. Therefore, in the helical antenna of the present invention, a freely bendable coil element is covered with an elastic synthetic resin or rubber tube, the lower end of the coil element is fitted and fixed to the upper part of the element mounting bracket, and the lower end of the coil element is fitted and fixed to the upper part of the element mounting bracket. Tighten the lower end screw portion to the base metal fitting, and fit the lower end portion of the tube extending downward from the lower end of the coil element into a recess provided in the base metal fitting whose top surface is open, and clamp it by the mounting metal fitting and the base metal fitting. This is what I did.

[Effect]

In the helical antenna according to the present invention, by tightening the element mounting bracket to the base bracket, the lower end of the elastic synthetic resin or rubber tube is fitted into the recess of the base bracket, and is clamped by the mounting bracket and the base bracket. Therefore, by firmly fixing the lower end of the tube, the pull-out strength and torsion strength in the rotational direction against the mounting bracket and the base metal are large, and the expansion and contraction of the tube due to temperature differences in the atmosphere are prevented by the base metal and the base metal. By being suppressed by the mounting fittings, the high temperature resistance of both of the above-mentioned strengths is improved.

【Example】

Below, Figures 1 to 3 will be explained for one embodiment of the present invention.
This will be explained with reference to the figures. As shown in FIG. 1, a bendable coil element 1 is similar to the conventional one, and a lower end portion of this element 1 is fitted and fixed to a small diameter upper portion 5a of an element mounting bracket 5, which will be described later. As shown in FIGS. 1 and 3, the mounting bracket 5 has a small-diameter upper portion 5a and a small-diameter lower end threaded portion 5c via steps 5d and 5e above and below the large-diameter intermediate portion 5b. Each is formed integrally. As shown in FIGS. 1 and 2, an elastic tube 2 made of a synthetic resin such as vinyl chloride or rubber, whose lower end is narrowed and cut to a small diameter, is inserted from the lower end threaded portion 5c side of the mounting bracket 5 to the middle thereof. 5b and the outer peripheral side of the element 1 to cover these, and the constricted part 2a at the lower end of the tube 2 is inserted into the intermediate part 5b of the mounting bracket 5 and the step 5e at the lower end.
bring it into contact with. In this state, the mounting bracket 5 is fixed to the base metal fitting 3 by tightening the lower end threaded portion 5c of the mounting metal fitting 5 into the screw hole 3f opened at the bottom of the recess 3e provided in the large-diameter upper portion 3d of the base metal fitting 3. At the same time, the lower end of the tube 2 is fitted into the recess 3e in which the upper surface of the base metal fitting 3 is opened, and the constricted part 2a at the lower end of the tube 2 is connected to the step 5e at the lower end of the intermediate part 5b of the mounting metal fitting 5 and the recess 3e of the base metal fitting 3. It is fastened by the bottom of the. The configuration of this embodiment other than those described above is similar to the conventional helical antenna shown in FIGS. 4 to 6, and the same reference numerals as in FIG. 5 in FIG. 1 indicate corresponding parts.

[Effect of the idea]

As set forth above, according to the present invention, by tightening the element mounting bracket to the base metal fitting, the lower end of the elastic synthetic resin or rubber tube is fitted into the recess of the base metal fitting, and the lower end of the tube made of elastic synthetic resin or rubber is fitted into the recess of the base metal fitting. Since the tube is clamped with metal fittings, the tube has a high pull-out strength and a high torsional strength in the direction of rotation, and the pull-out strength and torsional strength do not change even when the atmosphere returns from a high temperature state to room temperature.
The high-temperature resistance of both of the above-mentioned strengths is improved, so that the tube can be prevented from being damaged, and it is possible to provide a helical antenna that can be stably used for a long period of time.

[Brief explanation of the drawing]

1 is a half-cut front view showing the lower part of a helical antenna according to an embodiment of the present invention; FIG. 2 is a half-cut front view showing the lower part of the tube; FIG. 3 is a front view showing the element mounting bracket; The figures are a front view of a conventional helical antenna, FIG. 5 is a half-cut front view showing the lower part of the same tube, and FIG. 6 is a half-cut front view showing the lower part of the same tube. 1...Coil element, 2...Tube, 2
a... Throttle part, 3... Base metal fitting, 3a... Upper end small diameter part, 3b... Tapered upper part, 3c... Mounting screw part, 3d... Large diameter part, 3e... Recessed part, 3f...
Screw hole, 4... Cap, 5... Element mounting bracket, 5a... Upper part, 5b... Middle part, 5c...
Lower end threaded portion, 5d, 5e... stage.

Claims (1)

[Scope of utility model registration request] A bendable coil element is covered with an elastic synthetic resin or rubber tube, the lower end of the coil element is fitted and fixed to the upper part of an element mounting bracket, and the lower end threaded part of this mounting bracket is tightened to the base bracket. , a lower end portion of the tube extending downward from the lower end of the coil element,
A helical antenna, characterized in that the helical antenna is fitted into a recess provided in the base metal fitting and whose upper surface is open, and is clamped by the mounting metal fitting and the base metal fitting.