JPS637206Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a flexible tube that connects the distal end of an insertion section that is delivered to a subject part inside the body and a manual operating section outside the body in an endoscope device, and in particular, The object of the present invention is to provide a flexible tube that is not only flexible but also prevents its expansion and contraction and has good followability to twisting operations.

Of course, this kind of flexible tube must be able to bend freely along the body introduction route during the process of sending the tip of the insertion part into the test area in the body cavity.
In order to prevent damage to the insertion channel of a glass fiber or forceps placed in the tube by bending, the flexible tube itself must not be stretched or contracted in the longitudinal direction. In particular, the optical fiber bundle conducted within the flexible tube is susceptible to tensile force or compressive force, and if the flexible tube expands or contracts, it may cause breakage damage. Furthermore, the operation of directing the observation direction by the objective optical system provided at the tip of the insertion section to a desired direction, the operation of directing forceps etc. to the intended part of the subject, and the insertion along the introduction route when inserting deep into the body. During operation, etc., there is a problem in that the twisting operation on the tube by the hand operation section must be followed smoothly all the way to the distal end of the insertion section.

A conventional flexible tube of this type has been proposed that consists of overlapping spiral tubes made by winding narrow metal strips clockwise or counterclockwise (Japanese Utility Model Publication No. 44635/1983). In this case, the flexibility of the flexible tube to follow the twisting direction is improved, but the compressive force exerted upon insertion into a body cavity is poor, and the tube lacks resistance to contraction.

In addition, a structure in which a laminated tube of synthetic resin layers with a knitted tube as a core is superimposed on the outside of a helical tube has been proposed (publication of Utility Model Publication No. 49-29109). It is impossible to prevent the flexible tube from shrinking because it swells in the outer circumferential direction due to the compressive force in that direction. It is necessary to make the knitted tube itself strong enough to withstand compressive force by alternately laminating synthetic resin with a core of It had

Such longitudinal shrinkage of the flexible tube, i.e.
As a simple means to prevent the tube diameter from expanding due to the compressive force applied during insertion into a body cavity, it is also possible to wrap a spiral tube around the outside of the knitted tube or to continuously fit a number of rings on the outside of the knitted tube. However, such a structure lacks resistance to the tensile force generated when pulling it out from the body cavity, and the tube gradually deteriorates with repeated use. It shrinks in diameter and loses its adhesion with the outer helical tube and ring, creating a compressive effect on the insertion channel for glass fibers, forceps, etc. housed in the tube, resulting in decreased flexibility and torsional followability. This resulted in a negative impact.

In this invention, a flexible tube consisting of a combination of a spiral tube and a knitted tube is made to be resistant to both elongation and contraction in the longitudinal direction of the flexible tube. It is an object of the present invention to provide a flexible tube that has good properties and is easy to manufacture. The details will be explained below with reference to the illustrated embodiments.

Fig. 1 is a partially longitudinal side view showing the configuration of the flexible tube for an endoscope of the present invention, in which a narrow metal band is wound in a left-handed manner with a predetermined pitch interval to cover a helical tube 1. A knitted tube 2 woven from thin wire is closely covered on the knitted tube 2, and a right-handed helical tube 3 similar to the spiral tube 1 is also tightly covered on top of the knitted tube 2, forming a triple structure as the main tube body. be. In this case, the positions of the helical tubes 1 and 3 may be replaced, and furthermore, the knitted tube 2 may be sandwiched between both right-handed or left-handed helical tubes. 4
is a soft plastic tube covering the structure.

FIG. 2 is a partially longitudinal side view showing another embodiment of the flexible tube for an endoscope according to the present invention. Similar to the embodiment shown in FIG. 1, the main tube body is made of a triple structure; In this example, a three-layered structure is employed in which knitted tubes 2a and 2b are tightly sandwiched between the inner and outer sides of the spiral tube 1 shown in FIG. 1, respectively. Note that the helical tube in this case is not limited to a left-handed spiral tube, and may of course be a right-handed spiral tube.

Spiral tubes 1 and 3 constituting the flexible tube of the present invention
As a single unit, the characteristic is that it generally expands due to tension in the longitudinal direction of the tube and contracts due to compressive force, but these spiral tubes have a relatively small amount of expansion and contraction, and in a relatively small expansion/contraction area, their diameter is almost the same. does not change. In contrast, tube 2 or 2a and 2b
When a tensile or compressive force is applied in the longitudinal direction of the tube, the thread or wire woven into the bias is stretched or compressed along the longitudinal direction of the tube and expands outward, so its diameter expands. It changes greatly with respect to shrinkage.

However, in the flexible tube of the present invention having the above-mentioned configuration, both such diameter contraction and expansion phenomena of the knitted tube are prevented. In the following, each embodiment will be explained. In the embodiment shown in FIG. 1, when a tensile force is applied in the longitudinal direction of the tube, a force is applied in a direction that stretches the knitted tube 2 due to the tension. In order for this to stretch, it tends to involve a large change in diameter (in this case, a change in the direction in which the diameter becomes smaller),
Since the inner diameter of the knitted tube 2 is maintained by the helical tube 1 whose diameter hardly changes even when it is stretched, the knitted tube 2 cannot be stretched, and eventually the flexible tube itself is stretched. Never happened. Next, when a compressive force is applied in the longitudinal direction of the tube, the knitted tube 2 shrinks and its diameter tends to increase; Since the flexible tube is held in place by

In this way, the flexible tube of the present invention has a triple structure in which the main tube body sandwiches the knitted tube 2 and the spiral tubes 1 and 3 are brought into close contact with each other. It never shrinks.

Therefore, even if the soft plastic 4 covering the main tube body is sufficiently flexible and thin, the flexible tube itself can withstand tensile and compressive forces.

Also, in the embodiment shown in FIG. 2, the spiral tube 1 that does not change in diameter due to expansion and contraction allows
In the stretching direction, the outer knitted tube 2b cannot stretch because its inner diameter is maintained.
In the direction of shrinkage, the inner knitted tube 2a has its outer diameter held by the helical tube 1 and cannot be shrunk. The main pipe body of the structure does not expand or contract in any way with respect to the tensile and compressive forces in the longitudinal direction of the pipe. Therefore, even if the main tube body is covered with a sufficiently flexible thin-walled soft plastic 4 as in the embodiment shown in FIG. 1, the flexible tube itself can withstand tensile and compressive forces.

Here, referring to the torsional followability of the flexible tube itself, the knitted tube itself is used as a component in order to provide followability to twisting motion, but in the flexible tube of the present invention, as shown in Fig. 1, Fig. 2 In both embodiments, the knitted tube exists in either the direction in which the helical tube spreads or the direction in which it is tightened during the twisting operation, so the contact pressure between the helical tube and the knitted tube increases. This allows the followability to be exhibited even better.

In this way, the flexible tube of the present invention has a triple-layered structure in which either the spiral tube or the knitted tube is sandwiched between the other tubular body, and the characteristics of each constituent material work synergistically. This not only prevents expansion and contraction of the tube in the longitudinal direction, but also strengthens the required followability by holding the inside or outside of the knitted tube by the helical tube when the flexible tube is twisted. It has become possible to achieve extremely good characteristics necessary for a flexible tube all at once, and to maintain flexibility and torsion followability over time, making it possible to This type of flexible tube exhibits extremely superior effects compared to other flexible tubes of this type.

[Brief explanation of drawings]

FIG. 1 is a partially longitudinal side view showing an embodiment of the flexible tube of the present invention, and FIG. 2 is a partially longitudinal side view showing another embodiment of the flexible tube of the present invention. 1, 3... Spiral tube, 2, 2a, 2b... Edited tube, 4... Soft plastic tube.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A flexible tube for an endoscope in which a main body consisting of a combination of a helical tube and a knitted tube is covered with an exterior tube made of soft plastic, etc. A structure characterized by having one layer sandwiched between the other and sticking together to form a triple layer. (2) The endoscope according to claim (1) of the utility model registration, which has a three-layered structure in which a helical tube and a knitted tube are brought into close contact with each other by sandwiching the inside and outside of the knitted tube with the helical tube. Structure of flexible tube for use. (3) The endoscope as set forth in claim (1) of the utility model registration, which has a three-layered structure in which a helical tube and a knitted tube are brought into close contact with each other, and the inner and outer parts of the helical tube are sandwiched between the knitted tubes and brought into close contact with each other. Structure of flexible tube for use.