JPS6032415Y2 - Multi-stage telescopic tube - Google Patents

Description

[Detailed Description of the Invention] (Symmetry of the Invention...Field of Industrial Application) The present invention is designed to incorporate a plurality of tubes with different diameters, as is known as a telescopic rondo antenna for radios, televisions, etc. This relates to a multistage telescopic tube that is fitted outwardly to form a telescopic type, and more specifically, a predetermined sliding force and rotational force are applied between the tubes within the gap between the tubes that make up the tube. The present invention relates to an improvement in an elastic member interposed to provide the following properties.

(Prior art) Conventionally, this type of telescopic multi-stage telescopic tube has been constructed by interposing an elastic member in the gap between an inner tube and an outer tube that fit into each other to apply a predetermined sliding force and rotational force between the tubes. It has a structure that gives.

As for this elastic member,
There are two cylindrical antennas, and one consisting of two semi-cylindrical elastic pieces as a set.In the case of the above-mentioned telescopic rod antenna, the gap between the inner tube and the outer tube is 0. .2~0
．． Due to the small dimensional gap of 3 ribs, it is difficult to fit the cylindrical type in the former item (■) into the gap during assembly, and even if it is inserted, the frictional force is too strong and an appropriate sliding force cannot be obtained. Therefore, generally speaking, a set of two semi-cylindrical elastic pieces is inserted in the gap between the inner tube and the outer tube so as to face each other.

Here, an example of a multi-stage telescopic tube using the above-mentioned type of elastic member will be explained with reference to the drawings. The outer outer tube constituting the telescopic tube, 2 is the inner inner tube,
In the gap between the outer tube 1 and the inner tube 2, two semi-cylindrical elastic pieces 4, 4, as shown in a perspective view in FIG. 1, are interposed as a pair so as to face each other. has been done.

This elastic piece 4 has blind protrusions 5 protruding from the center of each lower end that are respectively engaged with a pair of holes 3 provided opposite to each other at the lower end of the inner tube 2, so that the inner tube 2 and the outer tube are 1, and thereby a predetermined sliding force and rotating force are applied to each other between the tubes.

In the case of the conventional elastic piece 4, the entire elastic piece 4 is formed into a straight semi-cylindrical shape with a circular arc having a constant radius.

This is for manufacturing reasons, namely, the elastic piece 4 is manufactured by punching a plate material with a constant thickness, but in this case, the arc surface of the elastic piece has a complex combination of radii (three-dimensional curved surface). When processing, the elongation and contraction rates of each part are different, and even when plastically deformed, springback occurs, and the springback value tends to vary in each part, resulting in product variations and defective products. This is because there is an inconvenience.

In particular, when the elastic piece 4 is formed into a straight semi-cylindrical shape with a circular arc of a constant radius as described above, the elastic piece 4 is fixed to the inner tube 2 through a blind protrusion 5 provided at the center of the lower end. Since the structure is such that the arc surface of the elastic piece 4 is shown in Figures 3 and 4.
As is clear from the figure, when the curvature of the circumferential surface of the inner tube 2 is made larger and the elastic pieces 4 are inserted in the gap between the outer tube 1 and the inner tube 2, each elastic piece 4 The inner surface along the direction abuts the circumferential surface of the inner tube 2, the left and right edges 4a in the width direction expand outward, and the longitudinal surfaces of the left and right edges 4a elastically contact the inner surface of each tube 1. In this way, the elasticity of bending in the width direction allows the outer tube 1 and the inner tube 2 to obtain a predetermined moderate sliding force and rotational force, and when the inner tube 2 is extended, the above-mentioned The upper end of the elastic piece 4 is
The tube is prevented from being pulled out by hitting the upper end constricted portion 6 of the outer tube 1.

(Technical problem of the present invention) The conventional elastic piece 4 as described above has the following drawbacks.

(i) First, when the elastic piece 4 is formed by punching, a single burr is formed on the end face of the punched periphery, although it is minute, and the left and right side edges 4a where this burr is formed are on the outside. Since it comes into sliding contact with the inner surface of the tube 1 under pressure, scratches or grooves occur on the inner surface of the outer tube 1 at various places due to the effects of the burrs and the 1 edge, which hinders sliding and prevents rotation. This poses an even bigger problem.

(ii) Furthermore, since the elastic piece 4 is locked to the inner tube 2 only by the engagement between the blind protrusion 5 and the hole 3 on the lower end side, the upper part of the elastic piece 4 tends to tilt around the blind protrusion 5 at its lower end as a fulcrum. During sliding, the upper end of the elastic piece 4 may bite into the tube due to its inclination, making it impossible to slide.

(iii) Furthermore, the elastic piece 4 slides in pressure contact with the inner surface of the outer tube 1 on the sliding side, so that the surfaces of the left side edges 4a in the width direction over the entire length in the longitudinal direction slide in pressure contact with the inner surface of the outer tube 1 on the sliding side. The friction against the surface is large and the inner surface of the outer tube is severely worn, making it unsustainable for long-term use.

(iv) Furthermore, when incorporating the elastic piece 4, two elastic pieces 4 are inserted simultaneously into the hole 3 of the inner tube with the blind protrusion 5, and the widened left and right edges 4a are attached to the outer surface of the inner tube. The elastic piece 4 must be inserted into the outer tube 1 while narrowing along the outer tube 1. In this case, the elastic piece 4 can easily move left and right using the blind protrusion 5 as a fulcrum, and it can be inserted into the inner tube without getting caught on the outer tube. Inserting two pieces at the same time while narrowing the tube to fit the curvature of the pipe requires a gap of 0.2 to 0.3 wt L, which makes rough insertion very difficult and requires skill, and the elastic pieces 4 are deformed when assembled. This may result in installation failure.

(Objective of the present invention) The present invention improves the elastic piece so as to eliminate all of the drawbacks (i) to iv) above, and makes it easy to incorporate the elastic piece.
The purpose of the present invention is to provide a multi-stage telescopic pipe that can be accurately assembled, facilitates assembly of the telescopic pipe, has little wear on each part even during long-term use, and can maintain a good telescopic state during assembly for a long time. be.

(Technical configuration of the present invention) For this purpose, the present invention provides an elastic piece interposed in the gap between the inner tube and the outer tube, so that its entire length in the longitudinal direction is on the circumferential surface of the inner tube in the radial direction of the tube. It has the same radius of curvature as the tube, and in the axial direction of the tube, the mountain part curves and bulges outward with a constant curvature, and is formed into a shape with a spherical bulge in the center in the longitudinal direction. The elastic piece contacts the inner tube along the circumferential surface of the inner tube at the inner surface of the upper and lower ends, and contacts the inner surface of the outer tube on the outer side (sliding side) at the upper and lower mountainous areas and along the bulge in the center. It is characterized in that only the convex surface of the protruding portion comes into surface contact with the elastic piece, and the left and right edges in the width direction do not come into contact with the inner surface of the outer tube.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

5 to 9 show an embodiment of the present invention, in which reference numeral 11 is an outer tube, 1 is an inner tube, 13 is a hole provided opposite to the lower end of the inner tube, and 14 is a pair of elastic pieces. A blind protrusion 15 provided at the center of the lower end fits into the hole 13 and is locked to the inner tube 12.

In the case of the present invention, the elastic piece 14 is formed into an arcuate surface whose entire longitudinal length from the upper end 14a to the lower end 14b has the same radius of curvature as the circumferential surface of the inner tube 12 in the radial direction of the tube. In terms of the axial direction, the upper and lower ends 14a, 14b
The intermediate portion thereof is curved and bulged outward with a constant curvature, and a spherical bulging convex portion 14c is formed at the longitudinal center portion.

Therefore, the inner surfaces of the upper and lower ends 14a and 14b of the elastic piece 14 are connected to the inner tube 1 as shown in the drawings (FIGS. 7 and 9).
The longitudinally intermediate portion is raised from the circumferential surface of the inner tube 12, and the convex surface of the bulging convex portion 14c at the center is elastically pressed against the inner surface of the outer tube 11. (Refer to Fig. 8 of the drawings.) In particular, as is clear from Fig. 8 of the drawings, only the convex surface of the bulging convex portion 14C is in surface contact with the inner surface of the outer tube 11, and both the left and right sides in the width direction The edge is configured not to contact the inner surface of the outer tube 11.

In the above embodiment, the dimensions of the main parts shown on the drawings are as follows.

Outer tube outer diameter 7 Inner tube outer diameter 6 mm Thickness of both tubes 0.2 Gap between both tubes 0.3 Diameter of hole 13 1.5 Length L of elastic piece 14 13 Length of upper end 14a Lll, 5 mm Length I of the lower end 14b, 22.5 Angle of the forward elastic piece 14: 0 134° (Effects of the present invention) With the above configuration, the present invention provides the following effects.

■ First, the edge of the elastic piece 14, which is prone to cracking during the molding process, does not contact the inner surface of the outer tube 11 on the sliding side at all, and only the convex surface of the bulging convex portion 14c at the center in the longitudinal direction Since it is configured to make surface contact with the inner surface of the outer tube, when sliding, the elastic piece 14
However, it does not damage the outer tube or affect the sliding force or rotational force.

■Furthermore, the central bulging convex portion 14c comes into pressure contact with the inner surface of the outer tube 11, and elastic force acts in all directions around the central bulging convex portion 14c, resulting in the effect of stabilizing the sliding force and rotational force. In addition, since the bulging part protrudes in a spherical shape, the elastic part does not wear out compared to conventional elastic pieces.
It can withstand long-term use, and on the other hand, since the bulge has a constant curvature in both the axial and radial directions, it is possible to obtain a product with high processing precision and high quality.

■Furthermore, the upper and lower ends of the elastic piece 14 are abutted at two points, upper and lower, along the outer diameter of the inner tube 12, so when sliding or inserting the elastic piece 14, the elastic piece 14 moves left and right, unlike conventional ones. It does not move, slides smoothly, and can be easily inserted.

■ Also, since the upper end of the elastic piece is in contact with the inner pipe and the central part is bulged, there is no part that gets caught when inserting it into the outer pipe, making it easy to insert and greatly simplifying the assembly of the telescopic pipe.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing a part of a conventional multi-stage telescopic tube, Fig. 2 is a cutaway side view of the same, Fig. 3 is a sectional view taken along line AA in Fig.
4 is a sectional view taken along line BB in FIG. 2, FIG. 5 is an exploded perspective view showing a part of the multi-stage telescopic tube of the present invention, FIG. 6 is a cutaway side view of the same, and FIG. C-C sectional view, Figure 8 is D in Figure 6
-D sectional view, and FIG. 9 is an E-C sectional view of FIG. 1... Outer pipe, 2... Inner pipe, 3...
... Hole, 4 ... Elastic piece, 5 ... Blind projection, 11 ... Outer tube, 12 ... Inner tube, 13
...hole, 14 ... elastic piece, 15 ...
... blind process.

Claims (1)

[Scope of utility model registration request] Two or more semi-cylindrical tubes are fitted inside and out, and each gap between the two tubes has a semi-cylindrical shape. In an extensible tube having a structure in which two elastic pieces are interposed and the elastic pieces apply a predetermined sliding force and rotational force to each other, each of the elastic pieces is A shape that has the same radius of curvature as the circumferential surface of the inner tube, and in the axial direction of the tube, the middle part curves and bulges outward with a constant curvature, and has a spherical bulging convex part at the center in the longitudinal direction. Each elastic piece contacts the inner tube along the curved surface of the inner tube at two points on the inner surface of each upper and lower end, and contacts the inner surface of the outer tube at the upper and lower middle portions and at the center. A multi-stage telescopic tube characterized in that only the convex surfaces of the bulging convex portions are in elastic surface contact, and the left and right edges in the width direction thereof are not in contact with the inner surface of the outer tube.