JPS6231944Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a coaxial conductive tube in which an outer pole group and an inner pole group, which can be expanded and contracted in multiple stages, are mutually insulated and arranged coaxially, and in particular, the proximal end of the inner pole group is arranged coaxially. The present invention relates to a telescoping coaxial conductive tube that can strengthen the connection between the conductive rod-shaped metal fittings and the conductive rod-shaped metal fittings connected thereto.

Conventionally, as shown in FIG. 1, an outer pole group 1 and an inner pole group 2, which are mutually extendable and retractable in multiple stages, are arranged coaxially, and insulation is provided between the poles 1a and 2a of each stage of both pole groups 1 and 2. The pole groups 1 and 2 are insulated from each other by intervening a conductive intermediate ring 3, and conductive cylindrical metal fittings 4 are attached to the poles 1a at both ends of the outer pole group 1, as shown in FIGS. 2 and 3. . Insulating bushes 8a, 8 between 7
A coaxial conductive tube in which the tubes 9a and 9b are arranged and connected integrally in a mutually insulated state is generally known. This type of coaxial conductive tube is usually used as an electrical conduction path that also serves as a support by having its proximal end fixed to a mounting base and directly fixing a microphone or the like to its distal end.

However, in the conventional coaxial conductive tube,
In particular, there is a problem with the connection structure between the proximal pole of the inner pole group and the conductive rod-shaped metal fitting.

That is, as shown in FIG.
is screwed onto the conductive rod-shaped metal fitting 7. Therefore, when a microphone or the like is fixed to the tip and rotated, the rotational force is transmitted to the base end pole 2a and the connection between the conductive rod-shaped metal fitting 7 and The connection may become loose.

Therefore, various structures have been proposed in the past to prevent this, but a rigid connection structure would complicate the structure, making it difficult to assemble, increasing the number of parts, and increasing costs. Due to their complexity, power supply failures were likely to occur, and both were impractical.

The present invention was devised in view of the current situation, and its purpose is to provide a structure that is simple in structure, capable of strengthening the connection between the pole and the conductive rod-shaped metal fittings, and that is expandable and retractable without the risk of power supply failure. The formula is to provide coaxial conductive tube.

Hereinafter, the present invention will be explained based on an embodiment shown in FIGS. 4 to 6.

In FIG. 4, reference numeral 11 denotes a four-stage extendable outer pole group, and the four outer poles 11a, 11b, 11c, 1
1d are each made of a metal tube, and a cylindrical metal fitting 12 for attaching a microphone (not shown) is fixed to the tip of the most extreme outer pole 11a by drawing and punching into two ring shapes. At the same time, the outermost pole 11d
A cylindrical metal fitting 13 for fixing the coaxial conductive tube to a mounting base or the like (not shown) is fixed to the base end of the tube by drawing and punching into two ring shapes. This cylindrical metal fitting 13 is provided with a male threaded portion 13a, and this metal fitting 13 itself also serves as a (-) side lug terminal.

Further, at the base end of each of the outer poles 11a, 11b, 11c except for the outermost pole 11d, the next outer poles 11b, 11c,
11d, and intermediate rings 15a, 15b, 15c made of an insulating material such as synthetic resin are fixed to the inner peripheral surface of the spring 14, respectively.
This provides insulation from the inner pole group 20, which will be described later. Each of these intermediate rings 15
a, 15b, 15c, as shown in FIG. It is designed to be isolated from the inside of the pole group 11. Each intermediate ring 15a, 15b, 15c is also formed with an annular convex portion 17 on its base end surface in the axial direction,
Further, the axial end surfaces of the intermediate rings 15b and 15c are each provided with a recess 18 into which the convex portion 17 of the adjacent intermediate ring 15a and 15b is fitted and locked at the contraction limit of the coaxial conductive tube.

Further, the tips of each of the outer poles 11b, 11c, and 11d except for the outermost pole 11a are folded inward, and each folded part 19 abuts the end surface of the spring 14 at the extension limit, and each outer pole 11a, 11b, 11c, and 11d are prevented from coming off.

On the other hand, the outer pole group 11 configured in this way
The inner pole group 20 is arranged coaxially inside the
The outer pole group 1 goes from the distal end to the proximal end.
Contrary to 1, the diameter is gradually reduced, making it expandable and retractable in four stages. Four inner poles 20a, 20b, 20c, 20 constituting this inner pole group 20
The poles d are made of metal, and the innermost pole 20d, unlike the other poles 20a, 20b, and 20c, is made of a solid bar.

As shown in FIG. 6, a male thread is cut at the base end of the inner pole 20d. It is screwed into the female thread provided. A plurality of radial recesses 22 are provided on the outer circumferential surface of the enlarged tip portion 21a, and this portion is thin.
The bottom of the inner pole 20d has a deep punching process 23 that reaches the male thread after screwing in the inner pole 20d.
is applied to prevent the screws from loosening.

Between the connecting fitting 21 and the cylindrical fitting 13,
A stepped cylindrical insulating bushing 24 and a dish-shaped insulating bushing 25 are inserted from both ends in the axial direction to completely insulate the opposing surfaces of the metal fittings 13 and 21 without any gaps. The insulating bushing 24 is made of, for example, a soft synthetic resin material, and a press-fitting allowance is provided in a portion of the bushing 24 corresponding to the enlarged tip 21a, as shown by a broken line 24A in FIG. Due to the existence of this press-fitting allowance, when the insulating bushing 24 is press-fitted (from the left to the right in FIG. 6) into the cylindrical metal fitting 13 with the rod-shaped metal fitting 21 attached, the material of the bushing 24 is A portion of the press fit portion escapes into the recess 22 and deforms accordingly. Further, a flange 24a is provided at the tip of the insulating bushing 24, and serves as a stopper during press-fitting.
At the contraction limit, the convex portion 17 of the intermediate ring 15c
An annular recess 24b into which is fitted and locked is formed.

A recess 2 formed at the base end of the insulating bushing 25
5a, an axial fitting groove 27 is provided at one location in the circumferential direction into which the rising portion of the (+) side lug terminal 26 is fitted to prevent rotation. The lug terminal 26 that is inserted together with the lug terminal 28 is fixed by a round nut 29 that is screwed onto the base end of the connection fitting 21.

Further, the most advanced inner pole 20a constituting the inner pole group 20 has a heat-shrinkable insulating tube 30 on its outer peripheral surface, as shown in FIGS. 4 and 5.
is designed to increase insulation with the attached outer pole group 11, and a rod-shaped connecting fitting 31 to be inserted into the cylindrical fitting 12 is drawn into a single ring-shaped strip at the tip thereof. and fixed by punching. Between this connection fitting 31 and the cylindrical fitting 12, a cylindrical insulating bushing 32 and a dish-shaped insulating bushing 33 are press-fitted from both ends in the axial direction, so that the opposing surfaces of the fittings 12 and 31 are press-fitted. The metal fittings 12 and 31 are completely insulated without any gaps, and both metal fittings 12 and 31 are connected together. A lug terminal 34 on the (-) side is clamped and fixed between the enlarged end portion of the insulating bushing 32 and the cylindrical metal fitting 12.
Further, a round nut 36 for fixing the (+) side lug terminal 35 is screwed onto the tip of the connection fitting 31 protruding from the insulating bush 32.

In addition, on the outer circumferential surface of the tip of each inner pole 20b, 20c, 20d except for the inner pole 20a at the leading edge,
Inner poles 20a, 20 located on the outer side in the radial direction
A spring 37 is fixed to each of the inner circumferential surfaces of the inner poles 20a and 20c to conduct electricity by contacting the inner peripheral surfaces of the inner poles 20a and 20c.
The proximal ends of the inner poles 20b and 20c are drawn on the inner side and are located on the inner side in the radial direction.
It is in contact with 0c and 20d. At the reduction limit, this drawn portion is fitted into and supported by the axial center portions of the intermediate rings 15b, 15c, as shown in FIG. 4.

In the above configuration, when assembling the base end portion of the conductive tube, first, the inner pole 20d at the proximal end of the inner pole group 20 is screwed into the connection fitting 21. Then, a punching process 23 is applied to the bottoms of the recesses 22 provided in advance at a plurality of locations on the outer circumferential surface of the enlarged tip portion 21a to the extent that they bite into the inner poles 20d. As a result, the connecting fitting 21 and the inner pole 20d are completely connected and fixed, and there is no possibility that the screwed state will loosen.

Next, this connecting fitting 21 is inserted into the cylindrical insulating bushing 24, and then these are press-fitted into the cylindrical fitting 13. Then, since the insulating bushing 24 is provided with a press-fitting body as shown by the broken line 24A in FIG. 6, the material of the insulating bushing 24 escapes into the recess 22 of the enlarged part 21a due to the deformation of the press-fitting allowance during press-fitting. The insulating bushing 24 deforms to follow the shape of the gap between the metal fittings 13 and 21. This effectively prevents the insulating bushing 24 from rotating and falling off.

Next, the proximal outer pole 11d of the outer pole group 11 is mounted on the cylindrical metal fitting 13, and two
A groove-like drawing process is applied to the strips to prevent them from coming off, and a punching process is applied to prevent them from rotating.

Next, an insulating bushing 25 is attached to the base end of the cylindrical metal fitting 13.
At the same time, heat-resistant washers 28 and lug terminals 26 are attached, and tightened with round nuts 29 to fix them.

When in use, the metal fittings 13 and 21 are fixed to the mounting base (not shown), and the metal fittings 1
Attach the microphone directly to the 2 and 31 sides. Then, the inner pole group 20 becomes a conduction path on the (+) side, the outer pole group 11 becomes a conduction path on the (-) side, and the conductive tube itself functions as a support.

By the way, when the microphone is rotated in this state, the rotational force is transmitted to the inner pole group 20 via the connection fittings 31 and the like. However, the innermost pole 20d at the proximal end has an integral structure with the connecting fitting 21 by the punched portion 23 as described above, and the punched portion 23 is
Since it is applied to the thin part of the bottom of the recess 22 and is sufficiently bitten into the inner pole group 20d, there is no possibility that the threaded state of the two may loosen.

In this way, it is possible to provide a robust conductive tube with a simple assembly structure and at low cost without the risk of power supply failure.

Although the present invention has been described above using an example of applying the present invention to the proximal end portion of a conductive tube, the present invention can be very easily applied to the distal end portion of a conductive tube by slightly modifying the structure. Note that the recess 22 may be formed into a ring groove shape.

As explained above, according to the present invention, it is possible to completely prevent power supply failures due to loosening of the connection between the pole and the conductive rod-shaped metal fitting, which frequently occurred in the past, with a simple structure, and it is easy to manufacture. can effectively suppress cost increases.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the conventional example, Fig. 2 is a sectional view showing the structure of the distal end of the conventional product, Fig. 3 is a sectional view showing the structure of the proximal end of the conventional product, and Fig. 4 is a sectional view showing the structure of the proximal end of the conventional product. FIG. 5 is a cross-sectional view of the upper half of the embodiment at the contraction limit, FIG. 5 is a cross-sectional view of the upper half of the main part at the extension limit, and FIG. 6 is a cross-sectional view showing details of the proximal end portion of the conductive tube. 11...Outer pole group, 11a, 11b, 11
c, 11d...outer pole, 12, 13...cylindrical metal fitting, 15a, 15b, 15c...middle ring,
20...Inner pole group, 20a, 20b, 20
c, 20d...inner pole, 21, 31...connecting fitting, 22...recess, 23...punch processing part, 24, 25, 32, 33...insulating bushing.

Claims (1)

[Scope of utility model registration request] An outer pole group and an inner pole group that are mutually expandable and retractable in multiple stages are arranged coaxially, and an insulating intermediate ring is interposed between the poles of each stage of both pole groups to insulate the pole groups from each other. Conductive cylindrical metal fittings are respectively fixed to the poles at both ends of the pole group, and conductive rod-shaped connecting fittings that are inserted into the cylindrical metal fittings are respectively fixed to the poles at both ends of the inner pole group, and between the two metal fittings. In a coaxial conductive tube which is integrally connected in an insulated state by disposing an insulating bush on the inner pole group, a male screw provided at the end of at least one pole of the inner pole group is screwed into a female screw portion of the rod-shaped connecting fitting, A recess is provided on the outer circumferential surface of the rod-shaped connection fitting corresponding to this female thread, and that portion is made thin, and the bottom of this recess is press-deformed to reach the pole end, thereby connecting the pole end and the rod-shaped connection fitting. They were connected together and an insulating bushing was attached to the outer periphery of the rod-shaped connecting fitting, and then they were press-fitted into the cylindrical fitting, and a part of the insulating bushing was caused to flow into the inside of the recessed part and deformed accordingly. A telescoping coaxial conductive tube characterized by: