Passive bending section for endoscope, and endoscope

Patent metadata

Field	Value
Publication number	US-9814373-B2
Application number	US-201615150965-A
Country	US
Kind code	B2
Filing date	May 10, 2016
Priority date	Dec 6, 2013
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

A passive bending section for an endoscope is disposed between an active bending section of an inserting section and a flexible tube of the inserting section and is passively bent by receiving an external force. In the passive bending section, a curvature gradually increases from the distal end portion of the passive bending section toward the proximal end portion of the passive bending section.

First claim

What is claimed is:

1. An endoscope comprising an operating section, a first helical tube that constitutes a flexible tube connected to the operating section and is disposed along a central axis direction, a first cover that covers an outer peripheral surface of the first helical tube, an active bending section that is disposed on a distal side of the flexible tube and is actively bent by an operation of the operating section, and a passive bending section that is disposed between the flexible tube and the active bending section along the central axis direction and is passively bent by an external force,
wherein the passive bending section comprises:
a distal end portion coupled with the active bending section;
a proximal end portion coupled with the flexible tube;
a second helical tube continuous with the first helical tube so that loosely wound portions in which thin plates are helically wound via clearances in the central axis direction and densely wound portions in which the thin plates are helically wound by bringing the adjacent thin plates into contact closely with each other in the central axis direction are alternately disposed along the central axis direction; and
a second cover that covers an outer peripheral surface of the second helical tube, and
in a first loosely wound portion disposed on a side of the distal end portion of a material forming the second helical tube and a second loosely wound portion disposed on a side of the proximal end portion of the material forming the second helical tube, a flexural rigidity in the second loosely wound portion is larger than a flexural rigidity in the first loosely wound portion,
a flexural rigidity of the first helical tube is smaller than a flexural rigidity of the second helical tube, and
the second cover is superimposed on a distal end of the first cover so that an inner peripheral surface of a proximal end of the second cover abuts on an outer peripheral surface of the distal end of the first cover in the flexible tube, and the second cover covers the distal end of the first cover.

2. The endoscope according to claim 1 ,
wherein the second cover is made of a material different from that of the first cover.

3. The endoscope according to claim 1 ,
wherein the first helical tube and the second helical tube are continuously and integrally formed by the helically wound thin plates.

4. The endoscope according to claim 1 ,
wherein the second cover of the passive bending section is extended to the active bending section, and covers the outer peripheral surface of the active bending section.

5. The endoscope according to claim 1 ,
wherein in the material forming the second helical tube, a pitch at which the thin plate is wound in the second loosely wound portion is narrower than a pitch at which the thin plate is wound in the first loosely wound portion, in the first loosely wound portion and the second loosely wound portion.

6. The endoscope according to claim 1 ,
wherein in the densely wound portion of the second helical tube, initial tension is given to the thin plates that come in contact adjacently and closely with each other in the central axis direction.

7. The endoscope according to claim 6 ,
wherein in the second helical tube, the initial tension given to the densely wound portion disposed on the distal end portion side is smaller than the initial tension given to the densely wound portion disposed on the proximal end portion side.

8. The endoscope according to claim 1 ,
wherein the first loosely wound portion is disposed at a distal end of the passive bending section, and the second loosely wound portion is disposed at a proximal end of the passive bending section.

9. The endoscope according to claim 1 ,
wherein the proximal end portion of the passive bending section is coupled to the flexible tube.

10. The endoscope according to claim 1 ,
wherein the distal end portion of the passive bending section is coupled to the active bending section.

11. An endoscope comprising an operating section, a first helical tube that constitutes a flexible tube connected to the operating section and is disposed along a central axis direction, a first cover that covers an outer peripheral surface of the first helical tube, an active bending section that is disposed on a distal side of the flexible tube and is actively bent by an operation of the operating section, and a passive bending section that is disposed between the flexible tube and the active bending section along the central axis direction and is passively bent by an external force,
wherein the passive bending section comprises:
a distal end portion coupled with the active bending section;
a proximal end portion coupled with the flexible tube;
a second helical tube continuous with the first helical tube so that loosely wound portions in which thin plates are helically wound via clearances in the central axis direction and densely wound portions in which the thin plates are helically wound by bringing the adjacent thin plates into contact closely with each other in the central axis direction are alternately disposed along the central axis direction; and
a second cover that covers an outer peripheral surface of the second helical tube, and
in a first loosely wound portion disposed on a side of the distal end portion of a material forming the second helical tube and a second loosely wound portion disposed on a side of the proximal end portion of the material forming the second helical tube, the number of windings of the thin plates wound in the second loosely wound portion is smaller than the number of windings of the thin plates wound in the first loosely wound portion,
a flexural rigidity of the first helical tube is smaller than a flexural rigidity of the second helical tube, and
the second cover is superimposed on a distal end of the first cover so that an inner peripheral surface of a proximal end of the second cover abuts on an outer peripheral surface of the distal end of the first cover in the flexible tube, and the second cover covers the distal end of the first cover.

Assignees

• Olympus Corp

Inventors

• Saito Kenichiro
• Kishi Takahiro

Classifications

• A61B1/0055 Primary

  Constructional details of insertion parts, e.g. vertebral elements · CPC title

• A61M25/0054

  with regions for increasing flexibility · CPC title

• G02B23/2476

  Non-optical details, e.g. housings, mountings, supports · CPC title

• A61M25/0045

  multi-layered, e.g. coated (coating materials A61L29/08) · CPC title

• A61M25/0138

  having flexible regions as a result of weakened outer material, e.g. slots, slits, cuts, joints or coils · CPC title