JPH05277061A - Flexible tube for endoscope - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a flexible tube for an endoscope in which flexibility is smoothly changed at a joint portion of a plurality of flexible tubes, and excellent insertability and durability can be obtained. The purpose is to do. [Structure] A plurality of flexible tubes 11 and 1 having different flexibility
In the flexible tube of the endoscope in which 2 is connected in the tube axis direction to the exterior, the end of the flexible tube 11 having the larger flexibility among the plurality of flexible tubes 11 and 12 on the joint side. The coating layers 13 and 14 made of a material harder than the flexible tube 11 are overlapped in the vicinity of the portion so that the thickness gradually increases toward the joint, and the flexibility of the overlapped portion is
The flexible tubes 11 and 12 before and after the joint are configured so as to gradually change in the middle of the flexibility.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible tube for an endoscope used for covering the insertion portion of the endoscope.

[0002]

2. Description of the Related Art A flexible tube of an endoscope has its flexibility changed midway in order to improve its insertability into, for example, a body cavity. It's soft.

FIG. 5 shows a flexible tube of such a conventional endoscope, in which the outside of a mesh tube 92 coated on the outer circumference of the double spiral tubes 90, 91 has different flexibility. A plurality of flexible tubes 93, 94 are connected to each other in the tube axis direction for exterior packaging.

The end surfaces of the flexible tubes 93, 94 are abutted against each other, and the outer circumference of each of the flexible tubes 93, 94 is formed thinly before and after the abutting portion. A material 95 similar to 94 is filled therein to ensure the watertightness of the abutting portion.

[0005]

However, as described above, in the structure in which the end faces of the flexible tubes having different flexibility are butted against each other, the flexibility of the flexible tube is sharply increased at the joint. Change.

As a result, when the vicinity of the seam is bent with a small radius of curvature, the flexible tube 93 side which is easily bent, that is, the flexible and soft flexible tube 93 side is abruptly bent, and the flexible tube is an inner mesh tube. Then, as shown in FIG. 6, uneven wrinkles are generated.

Then, only that portion is very easily bent, so that the insertability into the body cavity is remarkably deteriorated, and at the same time, the optical fiber bundle inserted inside is broken and the tubes are buckled. In many cases, heavy repairs had to be done.

Therefore, the present invention provides a flexible tube for an endoscope in which flexibility is smoothly changed at a joint portion of a plurality of flexible tubes and excellent insertability and durability can be obtained. The purpose is to

[0009]

In order to achieve the above object, a flexible tube of an endoscope of the present invention is an inner tube formed by joining a plurality of flexible tubes having different flexibility in the tube axial direction. In a flexible tube of an endoscope, a coating layer made of a material harder than the flexible tube near the end of the flexible tube having the larger flexibility among the plurality of flexible tubes near the joint portion side. Are gradually overlapped with each other toward the joint portion so that the flexibility of the overlapped portion gradually increases in the middle of the flexibility of both flexible tubes before and after the joint portion. It is characterized in that it is configured to change.

It is also possible to form the outer circumference of each of the flexible tubes narrow before and after the joint and bind the narrow portion with a thread. The outer surfaces of the plurality of flexible tubes may be formed of a similar synthetic resin material and covered with a skin layer made of a similar synthetic resin material so as to have a uniform outer diameter.

[0011]

Embodiments will be described with reference to the drawings. Figure 1
A flexible tube that covers the insertion portion of the endoscope to be inserted into a body cavity or the like is shown. Reference numerals 1 and 2 are double metallic spiral tubes wound in the left-right opposite direction, and on the outer surface thereof. A reticulated tube 3 formed by braiding fine wires made of metal or non-metal is closely adhered and covered. The present invention may be applied to a flexible tube other than the insertion section.

The outer surface of the reticulated tube 3 is covered with a plurality of flexible tubes 11 and 12 having different flexibility, which are joined in the tube axial direction. Of these, the first flexible tube 11 on the distal end side of the insertion portion is made of a material that is larger in flexibility and softer than the second flexible tube 12 on the proximal end side. Note that the flexible tube may be further connected by changing its flexibility in three or more stages.

The flexible tubes 11 and 12 are made of synthetic resin such as polyurethane or vinyl chloride, and are formed in a tubular shape in advance, and the outer surface of the mesh tube 3 is covered with the flexible tube 11 or 12 by adhesion or heat welding. Alternatively, the resin melted by the extruder may be applied to the outer surface of the reticulated tube 3 in a tube shape. Alternatively, another manufacturing method such as dipping may be used.

When manufacturing a flexible tube, as shown in FIG. 2, the first flexible tube 11 is formed on both inner and outer surfaces near the base end side (joint side) of the first flexible tube 11. Coating layers 13 and 14 made of a material harder than the flexible tube 11 of
By dipping, coating, etc., they are formed so as to be gradually thickened toward the end side.

Then, as shown in FIG. 1, after the mesh tube 3 is covered with the first and second flexible tubes 11 and 12, the end surfaces of the first and second flexible tubes 11 and 12 are joined to each other. Match each other.

The abutting portion (joint portion) has a dented portion 15 in both flexible tubes 11 and 12 by heat melting or the like.
Is formed, and the heat-melted or liquefied synthetic resin layer 16 is filled in the recess 15 and connected to the first and second flexible tubes 11 and 12, whereby the processing of the joint is completed.

The hardness of the coating layers 13 and 14 is the first.
In consideration of the hardness of the second flexible tubes 11 and 12 and the thickness of the coating layers 13 and 14 thereof, the flexibility of a part of the coating layers 13 and 14 is the first flexibility. The hardness is selected such that the flexibility of the tube 11 gradually approaches the flexibility of the second flexible tube 12.

Ideally, it is most desirable that there be no discontinuous change in flexibility at the joint, that is, at the abutting portion of the first and second flexible tubes 11 and 12. In this way, if the flexibility of the flexible tube changes smoothly at the joint between the first and second flexible tubes 11 and 12, it is possible to bend the flexible tube with a small radius of curvature. The flexible tube is bent into a smooth shape, and the flexible tube 11 from the reticulated tube 3,
No peeling or wrinkling of 12

The coating layer 13 inside the first flexible tube 11 may be formed on the mesh tube 3 side. Further, as shown in FIG. 3, the coating layer 14 may be formed only on one side of the flexible tube 11.

FIG. 4 shows a second embodiment of the present invention, in which the first and second flexible tubes 11 and 12 are made of the same kind of synthetic resin material and made of the same kind of synthetic resin material. Due to the skin layer 17, the first and second flexible tubes 1
The outer surfaces of 1 and 12 are coated so as to have a uniform outer diameter. By forming in this way, it is possible to prevent the outer diameter of the flexible tube from becoming uneven.

Further, in the second embodiment, the dent portion 15 formed in the joint portion is tightly bound with the thread 18 made of synthetic or natural fiber, and the skin layer 17 is formed on the outside thereof. By binding with the thread in this way, in combination with the smooth change in flexibility due to the provision of the coating layer 13, it is possible to more reliably prevent peeling and wrinkles from the reticulated tube 3.

[0022]

According to the flexible tube of the endoscope of the present invention, since the flexibility of the flexible tube changes smoothly at the joint portion of the plurality of flexible tubes having different flexibility, the flexible tube has a small curvature. Even if it is bent in a radius, it bends into a smooth shape, and the flexible tube is free from peeling and wrinkles, and excellent insertability and durability can be obtained. Then, if the joint is tightly bound, further excellent durability can be obtained.

[Brief description of drawings]

FIG. 1 is a partial side surface half cross-sectional view of a first embodiment.

FIG. 2 is a partial side sectional view of the manufacturing process of the first embodiment.

FIG. 3 is a partial side cross-sectional view of the manufacturing process of the first embodiment.

FIG. 4 is a partial side half-sectional view of the second embodiment.

FIG. 5 is a partial side half-sectional view of a conventional example.

FIG. 6 is a side view showing a usage state of a conventional example.

[Explanation of symbols]

 11 Flexible tube with greater flexibility 12 Flexible tube with less flexibility 13 Coating layer 14 Coating layer

Claims (3)

[Claims] 1. A flexible tube for an endoscope in which a plurality of flexible tubes having different flexibility are joined together in the tube axis direction for exterior packaging, wherein one of the plurality of flexible tubes having the greater flexibility is used. A coating layer made of a material harder than the flexible tube is laminated near the end of the flexible tube on the joint side so that the thickness gradually increases toward the joint. A flexible tube for an endoscope, characterized in that the flexibility gradually changes in the middle of the flexibility of both flexible tubes before and after the joint. 2. The flexible tube for an endoscope according to claim 1, wherein the outer circumference of each of the flexible tubes is thinly formed before and after the joint portion, and the thin portion is tightly bound with a thread. 3. A plurality of flexible tubes having different flexibility are formed of a similar synthetic resin material, and an outer surface of the plurality of flexible tubes is made uniform by a skin layer made of the same synthetic resin material. 1. The outer diameter is coated so that the outer diameter is large.
Or the flexible tube of the endoscope according to 2.