JPH0216885B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flexible tube for an endoscope used medically and industrially.

A conventional flexible tube for an endoscope consists of a flex made of a band-shaped plate wound spirally, a blade fitted around the outer periphery of the flex, and a resin outer sheath coated around the outer periphery of the blade. An adhesive is applied between the blade and the outer skin, and the adhesive is penetrated through the mesh of the blade to bond it to the flex. In other words, the above three components are integrally bonded together using an adhesive.

However, since the above three factors are integrated, the following problems occurred. That is, when a flexible tube is bent, the pitch of the flex tends to become smaller on the inside of the bend (smaller R side), and becomes larger on the outer side of the bend (larger R side). However, as mentioned above, since the above three are integrated, the blade is fixed to the flex and does not move, even though the gap between the flex plates becomes smaller on the inside of the bend, so the blade tries to bulge up and becomes attached to the outer skin. I arise. The occurrence of wrinkles leads to cracks in the outer skin and makes it difficult to insert the flexible tube into a bent body cavity. On the other hand, on the outside of the bend, even though the gap between the plates in the flex tends to increase, it is fixed to the blade and does not move, preventing it from bending. This effect of inhibiting bending significantly impairs the ease of inserting the flexible tube.

The present invention has been made focusing on the above circumstances,
The purpose is to provide a flexible tube for an endoscope that does not cause wrinkles on the outer skin even when bent and does not impair bending flexibility.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a medical endoscope 1. As shown in FIG.
This endoscope 1 includes an operating section 2, an insertion section 3 to be inserted into a body cavity, and a light guide cord 4. The insertion section 3 is formed by connecting a tip component 7 to the tip of a flexible tube 5, which will be described later, via a bending tube 6, and the bending tube 6 can be bent by operating an operation knob 8 of the operation section 2. The orientation of the distal end component 7 can be changed. In addition to the eyepiece section 9, the operation section 2 is provided with an air/water supply switching button, a suction operation button, a forceps insertion port, etc. (not shown). Further, internal components such as an image guide, a light guide, an air/water supply tube, a forceps channel, etc. (not shown) are inserted into the endoscope 1.

On the other hand, the flexible tube 5 in the insertion section 3 is constructed as shown in FIG. That is, it consists of a crush-preventing flex 14 made of a helically wound band-shaped metal plate, a tubular blade 15 fitted on the outer periphery of this flex 14, and a resin tube coated on the outer periphery of this blade 15. It has an outer skin 16. The blade 15 is formed into a tubular shape by knitting metal wires made of a fibrous material such as SUS or PB, thereby preventing twisting of the flexible tube 5.

Furthermore, a friction material 17 having a large friction coefficient is attached to the outer peripheral surface of the plate material of the flex 14. The friction material 17 is made by applying liquid synthetic rubber such as liquid silicone rubber or liquid natural rubber to the outer circumferential surface of the plate material by means of spraying, coating, dipping, etc., and then drying and solidifying it. After this drying process, a blade 15 is placed over the outer periphery of the flex 14. That is, the friction material 17 is interposed between the flex 14 and the blade 15, but is not fixed to the blade 15. In addition, the metal flex 14
When attempting to adhesively fix the friction material 17 to the outer circumferential surface of the roller, an adhesive such as a so-called primer is used, which can also be bonded to metal.

Further, the blade 15 and the outer skin 16 are integrally fixed by adhesive or other means. This can be done, for example, by applying adhesive to the outer periphery of the blade 15 and covering it with the resin tube to form the outer skin 16. in this case,
If the adhesive has the property of adhering to the friction material 17, the amount of application is adjusted so that it does not reach the inner surface of the blade 15 and adhere to the friction material 17.
However, this does not apply if the adhesive has a property that it does not adhere to the friction material 17.

When the flexible tube 6 is bent, the flex 14 contracts on the inside of the curve and its pitch becomes smaller, while the flex 14 stretches on the outside of the curve and its pitch increases. In response to this movement of the flex 14, the blade 15 moves via the friction material 17 and is not subjected to undue force. Therefore, on the inside of the curve, the excess length of the blade 15 is absorbed around the circumference and does not bulge up, so that the outer skin 16 does not wrinkle. Further, on the outside of the curve, the flex 14 is not restrained by the blade 15 and can freely and smoothly extend to a large extent.

In the above embodiment, the friction material 17 is attached to the flex 14 side, but the present invention is not limited thereto. For example, as shown in FIG. 3, a friction material 17 may be provided on the blade 15 side. That is, in this case, a raw material for the friction material 17 which has a large coefficient of friction and is highly elastic is applied to the inner surface of the blade 15 and dried to form the friction material 17. Such a blade 15
After covering the outer periphery of the flex 14, an adhesive is applied to the outer periphery of the blade 15 to cover the resin tube to form an outer skin 16. Even with such a flexible tube 5, the same effects as in the above embodiment can be obtained.

Further, in the present invention, the strands constituting the blade may be coated with a friction material in advance and the strands may be knitted to attach the friction material to the inner peripheral surface of the blade. Then, this blade is fitted onto the flex, the outer periphery of the blade is coated with an adhesive, and the outer periphery is further covered with an outer skin.

Further, a film or a tube serving as the friction material may be interposed between the outer circumference of the flex and the inner circumference of the blade.

As explained above, according to the present invention, when a flexible tube is curved, the outer skin does not wrinkle on the inside of the curve, which does not impede insertability, and there is no risk of cracking. Also, since the extension of the flex is not restricted by the blade on the outside of the curve,
The force resisting the elongation is small and flexibility is not impaired.

[Brief explanation of drawings]

FIG. 1 is a plan view of an endoscope showing one embodiment of the present invention, FIG. 2 is a partial sectional view of a flexible tube in the same endoscope, and FIG. 3 is a plan view of a flexible tube in another embodiment of the present invention. FIG. 3 is a sectional view showing only the main parts of the flexible tube. 5...Flexible tube, 14...Flex, 15...
Blade, outer skin, 17...friction material.

Claims (1)

[Claims] 1. A flexible tube for an endoscope, which has a flex formed by spirally winding a band plate, a tubular blade fitted on the outer periphery of the flex, and an outer skin covering the outer periphery of the blade, A flexible tube for an endoscope, characterized in that a friction material having a large friction coefficient is provided between the flex and the blade, and the blade and the outer skin are integrally fixed.