JPS602807Y2 - telescopic legs - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement in the structure of the joint portion of a retractable leg used for a cane, photographic tripod, etc.

Conventional joint tightening structures include one using multiple tapered rollers (Japanese Utility Model Publication No. 28-12175), and one in which the split piece is tightened by holding it against the inner pipe wall surface with a nut (Japanese Utility Model Publication No. 12175/1989). 51-7066), but the former taper OCt only applies lateral pressure to the inner pipe, but does not wedge into the gap between the inner and outer cylinders to exert a fixing effect, and therefore has a weak fixing effect. and the latter is
Because the structure uses a tightening nut (described as a female stopper in the official gazette) to press the split pieces onto the inner cylinder surface, not only is the holding force weak, but the split pieces do not fully return due to metal fatigue. There was a drawback that the inner cylinder could not be extended or contracted properly, or in extreme cases, the split pieces could be damaged, rendering the telescopic legs useless.

In addition, for tightening, insert a ring-shaped backing inside the nut.
Some types have a method in which when the nut is tightened, the lower end of the backing fits into a groove on the inner cylinder surface to ensure secure fixation.
When retracting the inner cylinder, the lower end of the backing gets caught in the groove, making it difficult to retract.Also, if it is left tightened for a long time, the lower end of the backing will deform and become unable to return to its original shape, making it difficult to tighten the legs. There was also the drawback that it would no longer be possible.

In the present invention, a friction part is provided on the upper outer periphery of the inner pipe, the outer diameter of the friction part is made smaller than the outer diameter of the inner pipe, and the boundary between the friction part and the smooth part is an inclined surface that expands toward the smooth part. Tonashi,
A wedge ring with externally tapered ends and a gap created by cutting one part of the cover wall is fitted onto the friction part of the inner pipe, and the thickness of the wedge ring is set so that the thickness of the wedge ring is equal to that of the friction part surface of the inner pipe and the outer part. By providing a telescopic leg that is larger than the gap between the inner pipe wall and externally fitted with a tightening nut on the inner pipe, it is easy to manufacture and does not have the above-mentioned drawbacks. This makes it possible to supply retractable legs with reliable effectiveness at a low cost.

An example of implementing the present invention will be described with reference to the drawings. 1 is an outer pipe, 2 is an inner pipe, 3 is a nut for tightening, and 4 is a wedge ring.

An outer pipe male thread 5 is cut at the lower end of the outer pipe 1.

The outer diameter of the inner pipe 2 is slightly smaller than the inner diameter of the outer pipe 1 so that the inner pipe 2 can fit into the outer pipe 1 and freely slide up and down.

A friction part 7 is formed on the outer periphery of the upper part 6 of the inner pipe 2, and the outer diameter of the friction part 7 is made smaller than the outer diameter of the inner pipe 2.

The purpose of the structure of the friction part 7 is to increase the frictional resistance between the wedge ring 4 and the friction part 7 when tightening is done by screwing together the female thread 8 of the nut 3 with the male thread 5 of the outer pipe 1. Therefore, external thread cutting, ring groove cutting, or knurling is applied to this part to increase the frictional resistance.

The grooves or serrations cut in the axial direction of the inner pipe 2 are
Not desirable for this purpose.

The boundary between the friction part 7 and the smooth part 9 of the inner pipe 2 is the smooth part 9.
The slope portion 10 is enlarged toward .

Further, a wedge ring 4 is fitted into the friction portion 7 of the inner pipe 2.

The wedge ring 4 is tapered on the outside of both ends, and a gap 12 is provided by cutting off the ring group 11 at one place, as shown in FIG.

Therefore, the wedge ring 4 fitted in the friction part 7 is inserted into the smooth part 9 of the inner pipe.
When moved in the direction, the wedge ring 4 can easily move to the inner pipe smooth portion 9 along the slope 10 while opening the gap 12.

Note that the friction portion 7 is a portion corresponding to the lower part of the wedge ring 4.

It may be sufficient to simply perform external thread cutting, ring groove cutting, knurling, etc., or the entire upper part 6 of the inner pipe may be processed as shown in FIG.

Next, a locking ring 13 is located near the upper end of the inner pipe 2.
is fitted into the outer circumferential groove 14 of the inner pipe 2! There is.

The end face of the locking ring 13 is a plane perpendicular to the axial direction, and the ring base 1
As shown in FIG. 3, a gap 16 is provided at one location of 5.

The inner diameter of the locking ring 13 is made smaller than the outer diameter of the inner pipe 2, and when the locking ring 13 is opened and fitted into the outer circumferential groove 14, the locking ring 13 is elastically fitted into the outer circumferential groove 14. Therefore, even if the inner pipe 2 slides within the outer pipe 1, the locking ring 13
will not fall off during sliding.

In addition, a locking protrusion 17 made by partially pressing the wall of the outer pipe 1 protrudes into the inner cavity of the outer pipe 1, so when the inner pipe 2 is lowered, the locking ring 13 touches the locking protrusion 17. It hits and locks 7 the lowering of the inner pipe 2.

Next, the tightening nut 3 has a cylindrical shape with a slightly narrowed bottom, and a female thread 8 is cut in the lower part of the inner cavity.The inner diameter of the upper part is slightly larger than the outer diameter of the outer pipe 1, and the inner diameter of the lower part is that of the inner pipe 2. It is made slightly larger than the outer diameter.

Therefore, there is a gap 19 between the lower opening 18 of the tightening nut 3 and the inner pipe 2.

Further, the bottom of the tightening nut 3 near the lower opening 18 has a pressing slope 20 that slopes downward.

Next, the wedge ring 4 is a band-shaped ring with both ends tapered outward.
It is made of acetal resin (for example, Duracon product name), and its thickness t is made larger than the size d of the gap 22 between the friction portion 7 surface of the inner pipe 2 and the inner wall 21 of the outer pipe 1.

In addition, the height h of the ring base 11 of the wedge ring 4 is such that when the inner pipe 2 is pulled out from the outer pipe 1 and the locking ring 13 hits the locking protrusion 17 and the inner pipe 2 is stopped, the friction portion 7 is approximately equal to the length of the outer pipe 1 which is projected and exposed from the lower end of the outer pipe 1.

That is, the friction portion 7 of the inner pipe 2 protrudes and is exposed from the outer pipe 1 by the height h of the ring base 11 of the wedge ring 4.

Note that both ends of the ring group 11 are formed into an upper taper 23 and a lower taper 24, respectively, which are inclined outward.

The inner edge of the lower end of the outer pipe 1 is lightly chamfered to form a chamfered portion 25.

26 is the grip of the walking stick, 2'7 is the stone end, and 28 is the lowest pipe.

Now, the telescoping legs of the present invention have the structure as shown in the drawings and the above explanation, and are assembled and used as follows.

Regarding the telescopic walking stick shown in FIG.
is inserted into the inner pipe 2 cavity, and then the inner pipe 2 with the lowermost pipe 28 inside is inserted into the outer pipe cavity from the upper part of the outer pipe 1 as it is.

Next, when the inner pipe 2 and the lowermost pipe 28 are sequentially pulled out completely from the lower end of the outer pipe 1, the pipe 2°28 stops at the position where the locking ring 13 hits the locking protrusion 17, and the outer pipe Friction portions 7 are exposed at the lower ends of the inner pipe 1 and the inner pipe 2, respectively.

Next, fit the wedge ring 4 for the upper joint into the friction part 7 of the inner pipe 2 from the lower end of the lower pipe 28. To tighten the upper joint, fit the nut 3 from the lower end of the lower pipe 28; Screw the outer pipe 1 into the male thread 5.

Using the same procedure, attach the wedge ring 4 and tightening nut 3 for the lower joint to the lower joint.

Next, attach the grip 26 to the upper end of the outer pipe 1, and attach the grip 26 to the upper end of the outer pipe 1.
Attach the stone protrusion 27 to the lower end of 8 to complete the assembly.

The structure of the joint part of the telescoping leg of the present invention is as shown in FIG. 2 and as explained above. Therefore, the tightening shown in FIG. When the female screw 8 of the tightening nut 3 is screwed into the male screw 5 of the outer pipe 1, the pressing slope 20 at the bottom of the inner cavity of the nut 3 presses the lower taper 24 of the wedge ring 4, and the tightening is performed by pushing the lower taper 24 of the wedge ring 4. The wedge ring 4 moves upward and the upper taper 23 abuts against the chamfered portion 25 at the lower end of the outer pipe 1.

Furthermore, when the nut 3 is rotated and tightened, the pushing slope 20 strongly presses the wedge ring 4, so that the upper taper 2 of the wedge ring 4 is tightened.
3 is wedged into the gap 22 between the outer pipe 1 and the inner pipe 2, and the lower taper 24 is wedged into the gap 19 between the lower opening 18 of the nut 3 and the inner pipe 2 for tightening.

Furthermore, when the tightening nut 3 is strongly tightened until it stops rotating, the wedge ring 4 is strongly wedged into the upper and lower gaps 22.19, and due to the respective forces of the upper taper part 23 and the lower taper part 24, the wedge ring 4 is wedged. The ring 4 is strongly pushed in the direction of the friction part 7, and the bottom of the wedge ring 4 sinks into the friction part 7, exerting a strong frictional force and firmly fixing the outer pipe 1 and the inner pipe 2.

This fixation is much stronger than when the friction part 7 is smooth, and exhibits the characteristic that the inner pipe 2 will not separate and sink into the outer pipe 1 even if force is applied in the axial direction of the pipe. do.

In addition, since the thickness t of the covering wall 11 of the wedge ring 4 is larger than the size d of the gap 22 between the surface of the friction portion 7 of the inner pipe 2 and the inner wall 21 of the outer pipe 1, tightening is performed using the nut 3. Even if it is strongly tightened, the wedge ring 4 will not enter the gap 22 and lose its wedge action.

Next, when inserting the inner pipe 2 into the outer pipe 1 to shorten the length of the cane, loosen the tightening nut 3, the push slope 20 will go down, and the wedge ring 4 will be released. Stop the wedge action and return to the original position.

Therefore, when the inner pipe 2 is pushed up, the lower taper 24 of the wedge ring 4 is pushed and expanded by the slope 10 of the inner pipe 2, and the inner pipe 2 enters the wedge ring 4, and the inner pipe 2
easily rises into the outer pipe 1.

This movement was achieved by providing the slope 10, and the movement was smooth even during frequent expansion and contraction, and the wedge ring 4 taper part 23.2
4 is characterized in that it does not deform and impair smooth operation.

The telescoping legs of this invention can be used not only for the telescoping walking stick mentioned as an example, but also for photographic tripods, tripods for surveying instruments, and the like.

[Brief explanation of drawings]

Figure 1 is a side view of the telescoping cane according to the present invention, Figure 2 is a vertical sectional view of the main parts of the telescoping leg of the present invention, Figure 3 is a perspective view of the locking ring used in the present invention, and Figure 4 is a , also a perspective view of the wedge ring. In the figure, 1... Outer pipe, 2...
Inner pipe, 3...Tighten with nuts, 4...
・Wedge ring, 7...Friction part, 10...Slope, 19.22...Gap, 20...Press slope, 25... - Chamfered part.

Claims (1)

[Claim for Utility Model Registration] Among the telescopic legs used for walking sticks, photographic tripods, etc., the inner pipe is telescoped inside the outer pipe, and the female thread of the nut is tightened externally on the inner pipe. A type of expansion and contraction that screws into a male thread provided on the outer periphery and presses the end face of a wedge ring externally fitted near the top end of the inner pipe, as the cylinder nut is screwed in, thereby fixing both pipes so that they cannot move relative to each other through wedge action. In the leg, a friction part 7 is provided on the outer periphery of the upper part of the inner pipe 2, the outer diameter of the friction part 7 is made smaller than the outer diameter of the inner pipe 2, and the boundary between the friction part 7 and the smooth part 9 is defined as the smooth part. Slope 1 expanded towards 9
A wedge ring 4 with an external taper at both ends and a gap 12 formed by cutting one part of the covering wall 11 is externally fitted onto the friction part 7 of the inner pipe 2, and the thickness of the wedge ring 4 is The expansion/contraction device is characterized in that the distance t is determined from the size d of the gap 22 between the surface of the friction portion 7 of the inner pipe 2 and the inner wall 21 of the outer pipe 1, and a nut 3 is externally fitted to the inner pipe 2 for tightening. leg.