JPS6240164Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an elastic band for tightening, and more specifically to an elastic band used for tightening a polyethylene sleeve in a polyethylene sleeve construction method used for the purpose of corrosion protection of buried cast iron pipes.

Conventionally, when laying underground conduits using cast iron pipes,
Polyethylene sleeving is used to protect cast iron pipes from corrosion caused by groundwater and underground stray currents.

As shown in Figure 1, this polyethylene sleeve construction method involves placing a polyethylene sleeve B over the outer periphery of a cast iron pipe A to be buried, and then tightening it with a tightening elastic band C to fix the polyethylene sleeve B to the outer periphery of the pipe A. However, the cast iron pipe A is insulated from groundwater etc., and even if groundwater etc. enters between the polyethylene sleeve B and the cast iron pipe A, advection along the pipe axis direction is prevented. There is.

However, when tightening the tightening elastic band C, as shown in FIG. The portion C ₁ that is in contact with the outer periphery A′ is difficult to stretch due to contact friction, and only the non-contact portion C ₂ is intensively stretched, so that the tightening elastic band C is not stretched uniformly. Areas with concentrated elongation tend to form, and these areas tend to deteriorate, resulting in a service life that is less than the expected design value.Also, when fastener D is engaged, only the uncontacted area _C2 is stretched. This requires an extremely strong tensile force, making the engagement work difficult, and if the elastic band were to accidentally come off the hand at this time, there would be a large repulsive force, which could be dangerous. It was hot.

In view of the above-mentioned problems, this invention provides an elastic band for tightening that can be tightened with uniform elongation over the entire length even when both ends are supported and stretched, making it easy to perform reliable tightening work. The outer periphery of a cord having rubber-like elasticity is loosely covered with a tube having at least a low friction inner surface so as to be able to slide relative to each other. It is characterized in that a removable fastener is attached.

This invention will be explained below using examples.

FIG. 2 is a partially omitted sectional view of an embodiment of this invention, and FIG. 3 is a diagram showing the embodiment in use.

The tightening elastic band 1 of this invention is made of natural rubber,
At least the inner surface 11A is attached to the outer periphery of the string 10 having rubber-like elasticity such as synthetic rubber or synthetic resin.
A tube 11 having a low friction property is loosely covered so as to be relatively slidable, and both ends 10 of the string 10 are covered with a tube 11 having a low friction property.
A and 10B have fasteners 12A that can be engaged with and detached from each other,
12B is attached.

The tube 11 is, for example, a soft plastic tube coated with a lubricant such as silicone or wax, and in addition to the lubricant, a rubber anti-aging agent is coated or sealed. It may be configured in such a way that it can be done.

The tube 11 may be made into a bellows-like shape as shown in FIG. 4A, or a piston-like shape as shown in FIG.
The length may be adjusted, and the cord 10 may be configured to be expanded or contracted as desired depending on the length of the string 10.

To use the tightening elastic band 1 of this invention, after wrapping it around the outer circumference of the cast iron pipe A covered with a polyethylene sleeve,
If B is supported and pulled, the string 10 will become the tube 1.
1, it is stretched smoothly and uniformly over the entire circumference without experiencing any frictional resistance, and then when the fastener is engaged, the tightening work is completed.

This idea is structured as above, so
During tightening and extension, the friction between the string and the tightened object is
Since the tubes sufficiently reduce the tension, uniform elongation is achieved and the elongation does not concentrate locally.Coupled with the fact that the tube protects the string from the outside, it is extremely effective. The service life can be extended, and since the tensile force required during expansion and contraction is distributed over the entire circumference of the string, it can be reduced, and the tightening work can be performed easily and safely.

Incidentally, it is also possible to print and display a product symbol on the outer periphery of the tube, and it can also be used to indicate the product type.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the polyethylene sleeve construction method, Fig. 2 is a partially omitted sectional view of an embodiment of this invention, Fig. 3 is a sectional view showing the usage state of the embodiment, and Fig. 4 A and B are other illustrations. FIG. 3 is a side view of the embodiment of FIG. 1... Elastic band for tightening, 10... String, 11
...Tube, 11A...Inner surface, 12A, 12B
...Fascinators.

Claims (1)

[Scope of utility model registration request] The outer periphery of a string having rubber-like elasticity is loosely covered with a tube whose inner surface has at least low friction properties so as to be relatively slidable, and at both ends of the string,
An elastic band for tightening, characterized in that it is made up of mutually removable fasteners attached.