JPH0451765Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a bending tube constituting the bending part of an endoscope that can be bent freely by remote control, and in particular, the invention relates to a bending tube constituting a bending section of an endoscope that can be bent freely by remote control, and in particular, to a bending tube constituting a bending section of an endoscope that can be bent freely by remote control. This relates to improvements in parts.

[Prior Art] In general, the curved tube of this type of endoscope has a tongue piece with a connecting hole formed in each of a plurality of segment rings, and the tongue pieces of adjacent segment rings are stacked on top of each other. They are connected with rivets so that they can rotate freely. Conventionally, the tongues connected by the rivets were formed to have the same size.

[Problems to be solved by the invention] When the curved tube of an endoscope is bent by remote control, frictional resistance is generated at the contact surface between the tongues, which acts as a resistance force against the operating device. . In such cases, in the curved tube of a conventional endoscope, the overlapping tongues were formed to be the same size, so
Frictional force is generated on the entire surface of the tongue, and as a result, a large load is placed on the operating device, such as the operating wire.
Not only did it not provide smooth operability, but it also had drawbacks such as early breakage of the operating wire and the like.

This invention eliminates such conventional drawbacks and
It is an object of the present invention to provide a curved tube for an endoscope that has low frictional resistance generated at each connecting portion of the curved tube and has excellent operability and durability.

[Means for Solving the Problems] In order to achieve the above object, in the curved tube of the endoscope of the present invention, a part of the circumferential wall of the nodal ring protrudes in the tube axis direction to form a tongue piece, and By drilling a connecting hole in the tongue piece, overlapping the tongue pieces of adjacent joint rings, inserting a rivet into the connecting hole, and caulking one end of the rivet, the joint ring can be connected. In a curved tube of an endoscope that is rotatably connected, the tongue piece facing the side on which the rivet is crimped is formed smaller than the other tongue piece, and a hole is inserted into the tongue piece on the smaller side. It is characterized in that the diameter of the provided connecting hole is smaller than the diameter of the connecting hole bored in the other tongue piece.

[Operation] Since one of the overlapping tongues is formed smaller than the other, the contact area between the tongues is small, and therefore the frictional resistance generated on the contact surface is small.

Since the diameter of the connecting hole in the smaller tongue piece is smaller than the diameter of the connecting hole in the other tongue piece, the area of the smaller tongue piece can be taken up sufficiently.

[Example] Examples will be described with reference to the drawings.

FIG. 4 shows an endoscope according to an embodiment of the present invention, in which 1 is an operating section, 2 is a flexible insertion section, and 3 is a distal end main body in which an objective optical system and the like are incorporated. A curved portion 4 is formed between the insertion portion 2 and the distal end main body 3, and is bendable by remote control. This curved section 4 is formed by rotatably connecting a plurality of joint rings with rivets to form a curved tube, and the periphery of the curved tube is covered with an elastic material such as a rubber tube, and its basic structure is known. The end of an operating wire 5 is fixed to the most distal node ring or tip main body 3, and the operating wire 5 is passed through the node ring to the rear and is inserted into the operating section 1 in a known manner. is connected to the bending operation mechanism. Reference numerals 6 and 7 are operating knobs for pulling and operating the operating wire 5. By rotating the operating knobs 6 and 7, the operating wire 5 is pulled.
The curved portion 4 bends toward the towed side.

FIG. 2 shows a state in which a plurality of joint rings 11 constituting the curved portion 4 are rotatably connected by a rivet 12, and FIG. 3 is a cross-sectional view taken along the line -2.

The node ring 11 is made of, for example, a stainless steel pipe material, and has a pair of semicircular tongue pieces 13 protruding from one end thereof, facing each other, with a part of the peripheral wall protruding in the tube axis direction. .

Also, aligning with the pair of tongue pieces 13,
A pair of tongue pieces 14 are protruded from the peripheral wall of the node ring 11 adjacent to the tongue piece 13. These tongue pieces 13,
Both of the 14 parts are formed in a planar shape so as to overlap with each other, and each has a connecting hole 15, 1.
6 is drilled. Of the overlapped tongue pieces 13 and 14, the outer tongue piece 14 is formed to have a smaller radius than the tongue piece 13, as shown in FIG. The connecting hole 16 is formed to have a smaller diameter than the connecting hole 15.

In this embodiment, the rivets 12 are inserted into the connecting holes 15 and 16 from the inside of the joint rings 11, and the ends of the rivets 12 are crushed and caulked from the outside of the joint rings 11, thereby connecting a large number of joint rings 11. They are rotatably connected to form a curved tube. Therefore, when the operating wire 5 is pulled and the bending portion 4 is bent, the bending tube rotates while generating frictional resistance on the contact surfaces of the tongues 13 and 14, and the bending portion 4 is bent.

In the case of this invention, the radius of one tongue piece 14 constituting the connecting part of each node ring is set to the radius of the other tongue piece 14.
Since the tongue pieces 13 and 14 are formed smaller, the contact area between the tongue pieces 13 and 14 is small, and the frictional resistance generated on the contact surface is reduced.

Incidentally, even if the outer tongue piece 14 is formed smaller than the inner tongue piece 13 as described above, the connecting hole 16 of the outer tongue piece 14 has a smaller diameter than the connecting hole 15 of the inner tongue piece 13. A sufficient area is left in the outer tongue piece 14, so that the strength of the connecting portion is not impaired.

[Effects of the invention] According to the curved tube of the endoscope of the present invention, the contact area between the tongues is small, and therefore the frictional force generated there is small, so the curved portion can be smoothly bent. They have excellent operability, and also have the effect of being durable and having a small burden on the operating wires and the like that pull them.

[Brief explanation of the drawing]

Fig. 1 is a partial plan view of the connecting portion of the joint ring according to an embodiment of the present invention, Fig. 2 is a side sectional view thereof, Fig. 3 is a sectional view taken along the - line, and Fig. 4 is the entire endoscope. FIG. 4...Bending portion, 5...Operation wire, 11...Node ring, 12...Rivet, 13, 14...Tingle piece, 1
5, 16... Connection hole.

Claims (1)

[Claim for Utility Model Registration] A part of the circumferential wall of the joint ring is protruded in the direction of the tube axis to form a tongue piece, a connecting hole is bored in the tongue piece, and the tongue pieces of adjacent joint rings are connected to each other. In a curved tube of an endoscope, in which the above-mentioned joint rings are rotatably connected by inserting a rivet into the connection holes of the two and crimping one end of the rivet, the side on which the rivet is crimped. The tongue piece facing the side is formed smaller than the other tongue piece, and the diameter of the connecting hole drilled in the tongue piece on the smaller side is equal to the diameter of the connecting hole bored in the other tongue piece. A curved tube of an endoscope, characterized in that it is formed to have a diameter smaller than that of the curved tube of the endoscope.