JPH0522643Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a telescoping tube in which two or more pipes are telescopically fitted together.

[Prior Art] Various telescopic tubes have been manufactured in the past, which include an outer tube and an inner tube slidably inserted into the outer tube, and the inner tube is tightened by a coupler attached to the end of the outer tube. It is used in telescopic walking sticks for the physically handicapped, clothesline poles, tripods, fishing rods, and the legs of chairs, etc.

[Problems that the invention aims to solve] However, with conventional telescopic tubes, if the coupling by the coupler is loosened too much due to some operational error,
If the coupler is damaged, the overall length will be rapidly reduced, which is dangerous if the coupler is subject to heavy weight, such as a cane for the handicapped. In particular, when the coupler is made of plastic to reduce weight, the coupler is easily damaged.

The purpose of this invention is to provide a telescoping tube that does not suddenly shorten in overall length even if the coupler is loosened too much or is damaged, is highly safe, is lightweight and strong, and can expand and contract quickly. It is provided by.

[Means for solving the problem] The telescopic tube of this invention comprises an outer tube made of a thin metal pipe with a large-pitch spiral formed at its end, the outer tube having a spiral groove on the outside and a spiral ridge on the inside; an inner tube made of a thin metal pipe with an outer diameter smaller than the inner diameter of the outer tube and larger than the crest diameter of the spiral ridge on the inside of the outer tube, the outer tube having a spiral groove on the outside and a spiral ridge on the inside, the outer spiral groove being formed with a spiral that screws together with the spiral ridge on the inside of the outer tube and can be freely rotated and screwed, and the outer tube having a spiral groove and a spiral groove on the inside of the outer tube, the outer tube having a spiral groove and a spiral groove on the inside of the outer tube, the outer tube having a spiral groove that screws together with the spiral ridge on the inside of the outer tube, the inner tube having a spiral groove that screws together with the spiral ridge on the inside of the outer tube, the inner tube having a spiral groove that screws together with the spiral ridge on the inside of the outer tube, the inner tube having a tapered portion on the outer circumference of the end and a slit in the axial direction; an inner tube having a cylindrical collar with an inner thread that screws together with the outer thread of the collar,
and a cylindrical coupler having an inner circumferential tapered portion formed to correspond to the tapered portion of the collar. When the coupler and collar are tightly fastened together, the helical ridge of the collar tightly screws into the helical groove of the inner cylinder, and when the coupler and collar are loosened, the screw engagement is released or loosened, allowing the coupler to move freely in the axial direction.

[Operation and Effects of the Invention] In the telescopic tube of the present invention, the outer tube and the inner tube are always screwed together with a large pitch spiral, so there is no possibility of the coupler being damaged or the coupling between the coupler and the collar loosening. Even if the cylinder length exceeds the limit, the cylinder length will not suddenly shrink, resulting in high safety. In addition, the outer and inner cylinders are formed by providing a thin metal pipe with a large pitch spiral with grooves on the outside and ridges on the inside, making it lightweight and strong, and expands and contracts quickly. Can be done.

[Example] Next, this invention will be explained based on an example shown in FIGS. 1 to 4.

The telescopic cylinder 1 of the present invention has an outer cylinder 2 in which a large pitch spiral is formed at the end of a thin aluminum pipe 20, with grooves 21 on the outside and protrusions 22 on the inside.
Then, a thin-walled aluminum pipe 30 having an outer diameter smaller than the inner diameter of the outer cylinder 2 and larger than the diameter of the spiral ridge 22 has a spiral groove 33 on the outside and a spiral ridge 34 on the inside. , an inner cylinder 3 which is screwed into the spiral protrusion 22 and loosely fitted into the outer cylinder, a cylindrical collar 4 made of plastic, and a cylindrical coupler 5 made of plastic.

The collar 4 has a spiral protrusion 42 with a large pitch formed on the inner periphery 41, an external thread 44 formed on the outer periphery 43, an outer periphery tapered portion 47 at the end, and a plurality of slits (or notches) inward from the end. ) 45, and the inner periphery is provided with a step 48 and the outer cylinder 2
It has a small diameter so that it can be fitted into it, and one end 2A of the outer cylinder 2 is fitted into it.

In this embodiment, the collar 4 is fitted onto the outer cylinder 2 by protruding a spiral protrusion 49 from the inner periphery of the collar 4 and screwing the spiral protrusion 49 into the spiral groove 21 on the outer periphery of the outer cylinder 2. may be glued.

The coupler 5 has an inner thread 51 formed on an inner periphery 52 to be screwed into the outer thread 44 of the collar 4, and an inner periphery tapered part 53 formed at an end corresponding to the tapered part 47 of the collar 4. , is loosely fitted into the inner cylinder 3.

Spirals 21, 22, 33 of the outer cylinder 2 and the inner cylinder 3,
34 can be rolled at low cost by moving the pipe in the axial direction while rotating it and pressing a thin-blade roller against the outer periphery of the pipe. Also, according to this rolling process, there are spiral protrusions 2 on the inside and outside of the pipe at the same time.
2, 34 and the spiral grooves 21, 33 can be formed, and a spiral can be formed even in an extremely thin-walled pipe (for example, 1 mm or less in wall thickness), and unlike the case of cutting, the strength is reduced by reducing the cross-sectional area of the pipe. can also be prevented.

Next, how to use this telescoping tube will be explained.

FIG. 1 shows a state in which the collar 4 and coupler 5 are unscrewed. At this time, the spiral protrusion 42 of the collar 4
is loosely engaged with the spiral groove 33 of the inner cylinder 3, or is not engaged at all, and the inner cylinder 3 and the outer cylinder 2 can freely rotate and slide in the axial direction. Adjust the length.

Next, when the coupler 5 is twisted and firmly tightened to the collar 4, the outer circumferential tapered portion 47 of the collar 4 is tightened inward by the inner circumferential tapered portion 53 of the coupler 5, and the width of the slit 45 of the collar 4 is narrowed. The helical protrusion 42 and the helical groove 33 of the inner cylinder 3 are screwed together, and as shown in FIG. stick.

In this embodiment, the collar 4 and the coupler 5 are made of plastic, but they may also be made of metal such as aluminum pipes.Although aluminum pipes are used for the inner tube 3 and outer tube 2, they may be made of other metals such as copper or stainless steel. It's okay if it's hot.

5 and 6 show a second embodiment of the invention. This embodiment has a collar 6, which is the collar 4 of the first embodiment divided into a first collar 6A and a second collar 6B. The first collar 6A has a spiral protrusion 62 formed on its inner periphery 61 to engage with the spiral groove 33 on the outer periphery of the inner cylinder 3, and the outer periphery of one end is a tapered part 64, and the outer periphery of one end is tapered. ni slit 6
5 and one or more protrusions 652 on the side surface 651 of the second collar 6B (the other end).
has been established.

The second collar 6B has an inner circumference 63 that is connected to the outer tube 2.
The outer periphery has a tapered portion 66 at the other end, and one end of the outer peripheral surface 67 has an outer thread 68 that is screwed into the inner thread 51 of the coupler 5.
, and one or more of the protrusions 65 are formed on the side surface 67A of the first collar 6A (one end side).
2 is provided with a groove 69 that engages with the groove 69.

Note that the protruding portion 652 and the groove portion 69 are formed when the first collar 6A is connected to the coupler 5 in a state in which the spiral protrusion 62 of the first collar 6A is not screwed into the spiral groove 33 of the inner cylinder 3.
This prevents it from rotating in conjunction with the

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the first embodiment of the telescopic tube according to the present invention when not tightened, and FIG. 2 is a cross-sectional view of the first embodiment of the telescopic tube according to the present invention when tightened. Figure 3 shows the first telescopic tube according to the present invention.
4 is a cross-sectional view of the coupler of the first embodiment of the telescoping tube according to the present invention; FIG. 5 is a cross-sectional view of the coupler of the second embodiment of the telescoping tube according to the present invention. FIG. 6 is a sectional view of the collar of the second embodiment of the telescopic tube according to the present invention. In the figure, 1... telescopic tube, 2... outer tube, 3... inner tube, 4... collar, 5... coupler.

Claims (1)

[Scope of Claim for Utility Model Registration] 1) An outer cylinder made of a thin metal pipe with a large-pitch spiral formed at its end, with a spiral groove on the outside and a spiral ridge on the inside; , and has an outer diameter larger than the diameter of the spiral protrusion on the inside of the outer cylinder, the outer side is a spiral groove, and the inside is a spiral protrusion, and the outer helical groove is connected to the spiral protrusion on the inside of the outer cylinder. An inner cylinder made of a thin-walled metal pipe is loosely fitted into the outer cylinder, and an external thread is formed on the outer periphery, and the inner periphery is larger than the outer diameter of the inner cylinder. A spiral protrusion having a large inner diameter and capable of being screwed into the spiral groove of the inner cylinder is formed,
a cylindrical collar having an inner cylinder holding part with a tapered part on the outer periphery of the end and a slit formed in the axial direction, and a fitting part that is externally fitted and fixed to the end of the outer cylinder; a cylindrical coupler having an internal thread that is screwed into the external thread of the collar and an inner circumferential tapered part formed corresponding to the tapered part of the collar, and the coupler and the collar are strongly fastened. When the helical protrusion of the collar is tightly screwed into the helical groove of the inner cylinder, the screwing is released when the fastening is loosened, or the screwing is loosened and the collar can be freely displaced in the axial direction. A telescoping cylinder. 2) The collar includes a first collar having a spiral protrusion formed on the inner periphery, a tapered portion on the outer periphery of the end, and a slit in the axial direction, and a first collar having a thread formed on the outer periphery, and The telescoping tube according to claim 1, which is characterized by comprising a second collar screwed onto the tube end.