JPS6021534Y2 - telescopic tube - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a telescopic tube that fits telescopically and telescopically, and particularly relates to a structure that slides smoothly during expansion and contraction and reliably maintains its state during expansion and contraction.

Conventionally, telescopic tubes have been used in various products such as multistage telescopic antennas, microphone supports, and camera tripods.

What is desired for this expandable tube is that the expansion and contraction movement during expansion and contraction is smooth and can be performed smoothly with a light force, and that when the tube is fully expanded, a heavy object can be placed on the upper end of the tube without any additional operation. It is possible to maintain this state as firmly as ever.

By the way, to explain an example of a conventional telescopic tube, one or more plate springs are fixed to the outside of the lower end of the inner tube, and this plate spring is brought into sliding contact with the inner surface of the outer tube.

The leaf spring in this case has a relatively thin wall, and when fixed to the inner tube, it is fixed with a part floating, and it slides into only a part of the inner surface of the outer tube.

The partially floating fixation facilitates the deformation and return of the leaf spring during sliding, allowing light and smooth sliding. However, on the other hand, it is weak in holding when it is extended, and may shrink or shrink under a slight load. When used during stretching, the holding force decreases and the product becomes unusable.

As an improvement to this, sliding is performed using a similar leaf spring, but a separate member is provided as a holding means, and the action of this separate member generates a strong pressure contact force on the inner surface of the outer tube, or a hole on the outer tube side. There are things that hold it firmly by engaging with it.

However, such a separate structure complicates the mechanism, is not cost effective, and has the drawbacks of poor appearance.

Other telescoping tube structures, such as camera tripods, include tightening with a tapered sleeve when expanded, which can also be firmly held and fixed, but this method tightens the expanded sleeve and loosens the sleeve prior to contraction. operation is very complicated.

This method is different from the method that does not require any separate operation, which is the object of the present invention, and is therefore excluded from the scope of the present invention.

In view of these points, the present invention provides inner and outer tubes that fit into each other in a nested manner, and a retaining plate is provided inside the upper end of the outer tube, and a spring plate is provided outside the lower end of the inner tube. The spring plate and retaining plate have both sliding and holding functions, allowing for smooth sliding during expansion and contraction operations and secure retention during expansion without any additional operations. This is what we provide.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, reference numeral 1 indicates a large diameter outer tube 2.
It is a small-diameter inner tube that expands and contracts upward, for example, by being inserted into the inside of the dog and fitting into the puppy.
A locking and holding plate 4 is provided inside the upper end of each.

The spring plate 3 has a bottom shape by punching out a relatively thick plate of spring material such as phosphor bronze that has good sliding properties against the metal outer tube 1, and has a wide annular portion 3a and its upper end. It has a locking part 3b which is provided in a protruding manner.

The annular portion 3a has an inner diameter equal to the outer diameter of the inner tube 2, fits closely to the outer surface 2a of the inner tube, and has its lower end fixed to the lower end of the inner tube 2 by brazing or other methods, Furthermore, adjust the outer diameter to outer tube 1.
A gap that allows smooth sliding against the inner diameter of the
If you use a pole of about 0. It is set at about Q5mm and is approximately equal to the inner diameter of the outer tube.

A slit groove 5, which serves as a guide for preventing rotation of the inner tube 2, is formed to penetrate in the axial direction at one location on the circumference of the annular portion 3a, for example, at a position facing the locking portion 3b.

The locking portion 3b extends from a pair of locking pieces 7, 7' which are divided into left and right halves by a central cut 6, and the locking piece 7 is attached to the annular portion 3a.
It has a wide guide part 7a with chamfered corners from the side, and a hook part 7b consisting of a narrow part and a semicircular bulging part, and the other locking pieces 7' are formed in exactly the same way. .

Further, a hole 8 is formed in communication with the lower end of the cut 6 on the side of the annular portion 3a, and the pair of locking pieces 7, 7' are displaced from side to side relatively largely through this hole 8, thereby imparting elasticity. ing.

The locking holding plate 4 is formed integrally with the outer tube 1 and is folded back inward to fix the upper end to the upper end of the outer tube 1 and form a wide annular shape that closely contacts the inner surface 1a of the outer tube, thereby maintaining this locking. A guide hole 11 and a locking hole 9 having the same shape as the outer shape of the locking portion 3b are punched out from the lower end of the plate 4 and are formed in communication with each other.

Furthermore, protruding ribs 10 that fit into the slit grooves 5 are provided in a straight line at positions facing the locking holes 9 and the like in the entire area below the locking holding plate 4 on the inner surface 1a of the outer tube 1.

In this way, either the inner tube 2 having the spring plate 3 on the outside of the lower end, or the spring plate 3
The annular portion 3a is brought into sliding contact with the inner surface 1a of the outer tube, the slit groove 5 is fitted into the protruding rib 10, and the tube is inserted so as to be expandable and retractable.

At this time, the annular portion 3a has a wall thickness that is in close contact with the outer surface 2a of the inner tube 2, and elastic deformation is extremely small, so that a light sliding force can be obtained, and the middle of the inner tube 2 can be properly locked and held by the retaining plate 4 on the left and right sides. By being held so that it does not swing, the inner tube 2 can smoothly move in and out of the outer tube 1 without rattling and can be expanded and contracted with a light force.

Further, the slit groove 5 and the protruding rib 10 are always fitted to restrict mutual rotation of the inner and outer tubes 1 and 2, and the inner tube 2 is reliably prevented from rotating during the above-mentioned expansion and contraction operations.

Next, when the spring plate 3 is fully extended, the spring plate 3 moves to the end of the path of the outer tube 1, and the annular portion 3a hits the retaining plate 4, thereby preventing the inner tube 2 from slipping out.

At this time, the locking portion 3b on the upper part of the annular portion 3a enters into the locking hole 9 of the locking holding plate 4, and the pair of locking pieces 7
, 7' are once narrowed and then elastically expanded to fit the guide portion 7a into the guide hole 11 and lock the hook portion 7b into the locking hole 9.

Therefore, even if a heavy object is added to the upper part of the inner tube 2, the locking force of the hook portion 7b with respect to the locking hole 9 prevents the inner tube 2 from shrinking downward and is maintained in this extended state.

On the other hand, in the case of contraction, when the inner tube 2 is pushed down with a little force, the hook portion 7b comes off from the locking hole 9 and the above-mentioned holding function is automatically released.

As described above, according to the present invention, the annular portion 3a of the spring plate 3 attached to the inner tube 2 can be smoothly expanded and contracted with a light force.
When this spring plate 3 is fully extended, it automatically locks onto the locking holding plate 4 on the side of the outer tube 1 and maintains the expanded state, making the expansion and contraction operation easy. Even if a heavy object is applied to the upper part, there is no problem such as the diameter shrinking for a long time and making it unusable.

It locks automatically when it is fully extended during extension, and the lock is automatically released by pushing down the inner tube 2 with a little force, so there is no need to perform any other operations, making it easy to operate. Since the inner tube 2 is prevented from rotating, the locking and its release are reliably performed.

Both the spring plate 3 and the retaining plate 4 can be formed by punching out a single plate, so they are easy to manufacture.

In the embodiment, the locking and holding plate 4 is integrally formed on the upper end of the outer tube 1 and then folded back and fixed, but the locking and holding plate 4 may be made of a separate member and fixed thereto.

BRIEF DESCRIPTION OF THE DRAWINGS The drawing is a perspective view showing an embodiment of the telescopic tube according to the present invention. 1... Outer tube, 2... Inner tube, 3... Curved spring plate, 3b... Locking part, 4... Locking holding plate, 5... Slit groove, 9... Locking hole, 10... Protruding rib.

Claims (1)

[Scope of utility model registration request] In an extensible tube that includes an outer tube and an inner tube that is extendably inserted into the inner tube, a spring plate that slides on the inner surface of the outer tube is provided on the outer periphery of the lower end of the inner tube, and the spring plate has an upward direction. A pair of locking pieces that protrude and are divided left and right from the cut end provided in the length direction of the tube, and a slit groove provided in the length direction of the tube are provided, and a slit groove is provided on the inner periphery of the upper end of the outer tube. A locking holding plate is provided which slides on the outer periphery of the inner tube and prevents the inner tube from being pulled out, and this locking holding plate has a locking hole that can engage and detach from the locking piece of the inner tube. The telescopic tube is further characterized in that the inner surface of the outer tube is provided with a protruding rib that fits into the slit groove and prevents rotation.