JPH08170613A - Expansion pipe - Google Patents

Abstract

PURPOSE: To positively lock a large diameter pipe and a small diameter pipe in the length adjusted state. CONSTITUTION: The tapered face 5 is formed at the tip part periphery of a sleeve 3 fixed to the end part of a large diameter pipe 1, and a thread 7 is provided on the peripheral surface of a cylindrical part continuous from the tapered face 5. Axial slits 8 reaching the rear end of the thread 7 from the tip of the sleeve 3 are formed at required spaces apart in the circumferential direction. The tapered face 11 is provided at the inner peripheral surface tip part of an operating cylinder 10 thread-engaged with the thread 7 of the slit 8. The tapered face 5 of the sleeve 3 is pressed inward by the tapered face 11 of the inner periphery by the clamping of the operating cylinder 10, and plural clamp pieces formed in a space to the sleeve 3 are deformed inward so as to clamp a small diameter pipe 2 inserted inside the large diameter pipe 1, thus preventing the relative movement of the large diameter pipe 1 and small diameter pipe 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telescopic pipe.

[0002]

2. Description of the Related Art A telescopic pipe in which a small-diameter pipe is slidably inserted inside a large-diameter pipe is very often used for a climbing rod, a mop handle and the like.

The length of the expandable pipe is usually adjusted by the relative movement of the large diameter pipe and the small diameter pipe.
It locks by the action of the lock mechanism to prevent relative movement of both pipes.

As a lock mechanism, a cylindrical body is fixed to an end portion of the small diameter pipe located in the large diameter pipe, and a crescent-shaped engaging piece is incorporated in an eccentric groove provided on the outer periphery of the cylindrical body. It has been known that the engaging piece is pressed against the inner peripheral surface of the large diameter pipe and the bottom surface of the eccentric groove by relative rotation of the small diameter pipe.

[0005]

By the way, in the expandable pipe having the lock mechanism as described above, since the engaging piece presses the large diameter pipe and the small diameter pipe in the radial direction in the locked state, the shafts of both pipes are locked. There is a problem that the expansion and contraction pipes are not well-formed because of a shift in the mind.

Further, since the expandable pipe is configured to be locked by the friction acting on the inner peripheral surface of the large diameter pipe and the bottom surface of the eccentric groove and the contact portion of the engaging piece, the locking effect is poor, and the locking and unlocking is not possible. There is a problem that the engagement piece is likely to be worn or settled by repeated operations, and the locking effect cannot be maintained for a long time.

An object of the present invention is to provide a telescopic pipe which can reliably lock a large-diameter pipe and a small-diameter pipe in a coaxially arranged state, and also can hold the locking effect for a long period of time. Is to provide.

[0008]

In order to solve the above-mentioned problems, in the present invention, a sleeve is fixed to the end of a large-diameter pipe into which a small-diameter pipe is slidably inserted, and the outer circumference of the tip of the sleeve is fixed. A taper surface is provided, a thread is formed on the outer periphery of the cylindrical portion following the taper surface, and a plurality of axial slits from the tip of the sleeve to the rear end of the thread are provided at required intervals in the circumferential direction. A configuration is adopted in which a taper surface for pressing the taper surface inward when the operation cylinder is tightened is provided at the tip of the inner circumference of the operation cylinder screwed to the screw of the sleeve.

[0009]

In the telescopic pipe having the above-mentioned structure, when the operating cylinder is tightened, the tapered surface of the operating cylinder presses the tapered surface of the sleeve in the radial direction, and the pressing causes the holding piece formed between the slits of the sleeve. The small diameter pipe is deformed inward and the outer periphery of the small diameter pipe is clamped, and the clamping is performed to lock the large diameter pipe and the small diameter pipe in a length adjusted state.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in the figure, a small diameter pipe 2 is slidably inserted inside the large diameter pipe 1, and a sleeve 3 is attached to an end of the large diameter pipe 1.

A step 4 is formed on the inner circumference of the sleeve 3, and the step 4 abuts against the edge of the large diameter pipe 1. This sleeve 3 is fixed to the end of the large diameter pipe 1 by means of adhesion.

A tapered surface 5 is formed on the outer circumference of the tip portion of the sleeve 3, and a screw 7 is formed on the outer circumference of the cylindrical portion following the tapered surface 5.
Is provided. A plurality of axial slits 8 extending from the front end surface to the rear end of the screw 7 are formed in the sleeve 3 at equal intervals in the circumferential direction, and a sandwiching piece 9 is provided between the adjacent slits 8.
It has been.

A tapered surface 11 is formed at the tip of the inner circumference of the operating cylinder 10 provided outside the sleeve 3, and the tapered surface 1 is formed.
Female thread 1 engaging with thread 7 of sleeve 3 on the inner periphery following 1.
2 are provided.

Now, when the operating cylinder 10 is tightened, the tapered surface 11 provided on the operating cylinder 10 presses the tapered surface 5 of the sleeve 3 inward, and the holding piece 9 is deformed inward by the pressing.

When the slit 8 forming the holding piece 9 has a length corresponding to the axial length of the tapered surface 5, the holding piece 9 is not easily deformed, and the holding piece 9 is deformed when the holding piece 9 is deformed. Only the tip portion comes into contact with the outer circumference of the small diameter pipe 2 and the small diameter pipe 2 cannot be firmly held.

Therefore, if the axial length of the tapered surface 5 is increased, the holding piece 9 having a long length and easily deformed can be formed, but in this case, the sleeve 3 becomes large. .

In the embodiment, since the slit 8 provided in the sleeve 3 has a length from the tip of the sleeve 3 to the rear end of the screw 7, it is a compact sleeve 3 but can be easily deformed. A piece 9 can be obtained. As the operation piece 9 is deformed inward by tightening the operation tube 10, the holding piece 9 comes into contact with the outer circumference of the small diameter pipe 2 from the tip of the inner circumference, and as the tightening amount of the operation tube 10 increases, the small diameter pipe 2 increases. The contact length of the holding piece 9 with respect to the outer periphery of is increased.

For this reason, the plurality of holding pieces 9 are the small-diameter pipes 2.
Is held very firmly, and the large-diameter pipe 1 and the small-diameter pipe 2 are reliably locked by the holding.

Since the plurality of holding pieces 9 are deformed inward by the pressing of the tapered surface 5 of the sleeve 3, the holding pieces 9 are held.
Is uniformly deformed inward, and the small diameter pipe 2 is the large diameter pipe 1
Are locked with their axes aligned with each other.

As described above, the holding piece 9 holds the small-diameter pipe 2 by the inward deformation, and the holding piece 9 presses the operation tube 10 by the restoring force due to the deformation.
Prevents 0 slack and holds the telescopic pipe securely in the locked state.

[0022]

As described above, in the telescopic pipe according to the present invention, when the operating tube is tightened, the tapered surface provided at the inner peripheral tip of the operating tube is sandwiched between the slits of the sleeve. Press the pieces inward, and each of the holding pieces deforms inward evenly by the pressing to hold the small diameter pipe, so both pipes expand and contract with the axes of the small diameter pipe and the large diameter pipe aligned. Can be locked.

Further, since the slit forming the holding piece has a length from the front end of the sleeve to the rear end of the screw,
The holding pieces are easily elastically deformed, and when the holding pieces are deformed inward, the holding pieces are pressed against the small diameter pipes in a long range, so that the expansion and contraction of the small diameter pipes and the large diameter pipes can be reliably locked.

Further, since the small-diameter pipe is held by the inward deformation of the plurality of elastic pieces, the elastic pieces are hardly worn and the locking effect can be maintained for a long time.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing an embodiment of a telescopic pipe according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is an exploded perspective view showing a sleeve and an operating cylinder of the same.

[Explanation of symbols]

 1 Large-diameter pipe 2 Small-diameter pipe 3 Sleeve 5 Tapered surface 7 Screw 8 Slit 9 Holding piece 10 Operating tube 11 Tapered surface

Claims (1)

[Claims] 1. A sleeve is fixed to the end of a large-diameter pipe into which a small-diameter pipe is slidably inserted, a tapered surface is provided on the outer circumference of the distal end of the sleeve, and a screw is provided on the outer circumference of a cylindrical portion following the tapered surface. Formed, a plurality of axial slits from the tip of the sleeve to the rear end of the screw are provided at required intervals in the circumferential direction, and at the inner peripheral end of the operating cylinder screwed to the screw of the sleeve, An expandable pipe provided with a tapered surface that presses the tapered surface inward when the operation tube is tightened.