JPH018726Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a steel pipe connecting device, and more specifically to an improvement of a single pipe joint for connecting temporary scaffolding frames made of steel pipes.

For example, a connecting device for vertically connecting temporary scaffolding steel pipes is, as shown in Fig. 1, provided with a support step 2 in the middle of the outer circumferential surface of a joint 1 serving as an inner pipe, and a pair of support steps 2 are provided at each end of the joint 1. It is constructed by providing an engaging notch 3 and also providing an engaging part 5 with the engaging notch 3 on a scaffold frame vertical pipe 4 serving as an outer pipe.

The engaging notches 3 provided in the joint 1 are provided at positions on both sides of the axis, and include a vertical notch 3a extending from the edge of the joint 1 in the axial direction, and a vertical notch 3a extending from the inner end of the vertical notch 3a approximately at right angles in the circumferential direction. Bent horizontal cutout 3b
The inner end of the transverse cutout 3b has an arcuate edge with a slightly larger diameter.

The engaging portion 5 provided on the vertical pipe 4 can be formed by providing on the inner surface of the vertical pipe 4 a diameter or size that fits the width of the engaging notch 3 .

By the way, as shown in FIGS. 2 and 3, the conventional hooking portion 5 includes one in which the circumferential wall of the vertical pipe 4 is punched out from the outside to the inside to form a hemispherical portion 5a;
As shown in FIG. 4, there is one in which a pin 5a is horizontally suspended within a vertical pipe 4.

When assembling temporary scaffolding steel pipes by connecting them vertically,
Depending on the location of the scaffolding steel pipe, there are cases where a compressive load is applied to the connection part and cases where a tensile load is applied.

In the case of a compressive load, since the end of the vertical pipe 4 comes into contact with the stepped portion 2 of the joint 1, no load is applied to the engaging portion between the engaging notch 3 and the engaging portion 5, and there is no particular problem.

On the other hand, the tensile load must be supported by temporary fixing by the engagement of the engagement notch 3 and the engagement portion 5, and the connecting device must be able to sufficiently withstand this tensile load.

In the above-mentioned joint 1, the strength of the end portion is reduced due to the formation of the engagement notch 3, and particularly the strength against tensile load is determined by the transverse notch 3b and the tongue piece 6 left between the edges.

By the way, when an upward tensile load is applied to the connecting device, that is, when the vertical pipe 4 above the joint 1 rises, its engaging portion 5 pulls up the joint 1 through the upper end engaging notch 3, and this joint 1 is a hooking notch 3 at the lower end, and the lower vertical pipe 4 is pulled up via the hooking portion 5.

Therefore, the joint 1 must support the tensile load with the tongue pieces 6 formed by the engaging notches 3 at the upper and lower ends.

The tongue piece 6 is the weakest part in terms of strength against tensile load and bending load, and if the engaging part 5 is formed into a hemispherical part 5a as shown in FIGS. 2 and 3,
When supporting a load, the tongue piece 6 is guided inward by the hemispherical part 5a, so that the tongue piece 6 separates from the inner circumferential surface of the vertical pipe 4 and finally leaves the hemispherical part 5a.

Further, when the engaging part 5 has a pin 5b structure as shown in Fig. 4, the pin 5a under load is bent as shown by the dashed line in the figure, and the tongue piece 6 is guided inward along the bent shape of the pin 5b. The vertical pipe 4 is bent away from the inner circumferential surface of the vertical pipe 4, and the load supporting strength is reduced.

In this way, all of the conventional engaging parts 5 cause the tongue pieces 6 of the joint 1 to bend inward when supporting a tensile load, reducing the load supporting capacity.

This idea was made in view of the above points, and the initial displacement of the tongue formed by the engaging notch when supporting the load is small.
Furthermore, it is an object of the present invention to provide a connecting device in which the deformation of the tongue acts in the direction of inscribing the outer tube, thereby increasing the tensile strength.

The structure of this device is to provide a pair of arcuate cuts that bulge away from each other at two positions along the axial direction on the circumferential wall of the outer tube, and to insert the part between the two cuts on the circumferential wall into the inside of the outer tube. It is formed into a protruding engaging portion whose upper and lower end surfaces are arcuate surfaces, and is configured to come into surface contact with an engaging notch formed in the inner tube during load support.

This invention will be explained below based on the embodiments shown in FIG. 1 and FIGS. 5 to 8 of the accompanying drawings.

The connecting device of this invention is as shown in Fig. 1.
It consists of a joint 1 and a vertical pipe 4 that is externally inserted into the joint, and the joint 1 has engaging notches 3 at both ends.
However, the vertical pipe 4 is also provided with engaging portions 5 for the engaging notches 3 at opposing positions across the axis.

As shown in FIGS. 5 and 6, the above-mentioned engaging portion is formed by making a pair of arcuate cuts 11, 11 at two positions along the inward direction of the axis on the circumferential wall of the vertical pipe 4, and between the arcuate cuts 11, 11. This portion is made to protrude inside the vertical pipe 4 to form the engaging portion 5.

The arcuate cuts 11, 11 are arranged with an interval that can pass through the width of the engaging notch 3, and are formed to bulge in a direction away from each other.

In the illustrated case, the engaging portion 5 has both arcuate cuts 11 and 1.
A crease line 12 is made in the direction of the central axis between 1 and 1, and a cross section V is formed on both sides of the crease line 12 to the inside of the vertical pipe 4.
It is formed by extrusion into a letter shape, and its upper and lower end surfaces are made into arcuate surfaces 13 that are equal to the arcuate cuts 11, 11.

The formation of the above-mentioned hooking part 5 is not limited to the cross-sectional shape as shown in the drawings; for example, it may be made to protrude in a U-shape in cross section, it may be made to protrude in a flat trapezoidal shape, or it may be formed by cutting off both sides from the central crease line. It may also be made to protrude.

The connecting device of this invention has the above-mentioned configuration, in which the joint 1 is fitted into the upper end of the lower vertical pipe 4, the lower end of the upper vertical pipe 4 is fitted onto the joint 1, and the engaging portion 5 of the upper and lower vertical pipes 4 is fitted. When engaged in the horizontal cutouts 3b of the engagement notches 3 at the upper and lower ends of the joint 1, the upper and lower vertical pipes 4 are connected via the joint 1 in a manner that prevents them from coming off.

Figures 6 to 8 show the load supporting state when a tensile load is applied to the lower connecting part of the joint 1, and the tongue 6 side of the raised transverse cutout 3b of the joint 1 is shown in Figs. The side edge comes into pressure contact with the lower arcuate surface 13 of the engaging part 5.

Although not shown in the drawings, at the connection portion at the upper end of the joint 1, the upper arcuate surface of the engaging portion 5 of the upper vertical pipe is in pressure contact with the side edge of the transverse cutout 3b on the tongue 6 side at the upper end of the joint 1. .

As shown in FIG. 6, the periphery of the transverse cutout 3b is arcuate, and the lower arcuate surface 13 of the engaging portion 5 and the joint 1
Surface contact is perpendicular to the axis of the

Therefore, the tensile load is supported by the surfaces of the engaging portion 5 and the tongue piece 6, and the initial displacement of the tongue piece 6 is less likely to occur.

In addition, since the deformation of the tongue piece 6 caused by supporting the tensile load occurs in the outward direction, that is, in the direction in which it comes into pressure contact with the inner peripheral surface of the vertical pipe 4, the vertical pipe 4 and the joint 1 are firmly locked and the tongue piece 6 is resistant. This will improve tensile strength.

As described above, according to this invention, arc-shaped cuts are made in two places in the axial direction on the circumferential wall of the outer tube so as to bulge out in the direction away from the other cuts, and the part between the two cuts is made inside the outer tube. Since the engaging part is made to protrude and the upper and lower end surfaces are arcuate surfaces, when a tensile load is applied, the engaging part comes into surface contact with the engaging notch perpendicular to the axis of the outer tube, and the tongue of the inner tube against the tensile load. The occurrence of initial deformation of the piece is reduced.

In addition, deformation of the inner tube tongue due to the tensile load occurs in the direction of pressure contact with the inner surface of the outer tube, and when a large tensile load is applied, the fitting portion of the inner tube and outer tube is firmly locked, and the above-mentioned engagement The tensile strength can be greatly improved by the surface contact between the part and the engaging notch.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing the basic structure of the connecting device, Fig. 2 is a vertical cross-sectional view of the conventional example showing the structure of the engaging part and the engaging notch in the above, Fig. 3 is a cross-sectional view of the same, and Fig. 4 is the same. Vertical sectional view showing another conventional example, No. 5
The figure is a perspective view showing the engaging part of the connecting device according to this invention, FIG. 6 is a longitudinal sectional front view showing the relationship between the above and the engaging notch, FIG. 7 is a longitudinal sectional side view thereof, and FIG. 8 is a lateral plan view thereof. It is. 1 is a joint, 3 is an engaging notch, 4 is a vertical pipe, 5 is an engaging part, 6 is a tongue piece, 11 is an arcuate cut, 1
3 is an arcuate surface.

Claims (1)

[Scope of utility model registration request] In a connecting device in which an inner pipe is provided with an engaging notch that bends radially in the axial direction from the end thereof, and an outer pipe that is fitted externally into the inner pipe is provided with an engaging part that engages with the engaging notch, At two positions in the axial direction on the peripheral wall,
A pair of arcuate cuts are provided that bulge in directions away from each other, and a portion of the peripheral wall between the arcuate cuts protrudes into the interior of the outer tube, forming an engaging portion with both end surfaces forming arcuate surfaces. A steel pipe connecting device featuring: