Bending operation mechanism

Patent metadata

Field	Value
Publication number	US-12202134-B2
Application number	US-202118034360-A
Country	US
Kind code	B2
Filing date	Oct 29, 2021
Priority date	Oct 30, 2020
Publication date	Jan 21, 2025
Grant date	Jan 21, 2025

Abstract

A bending operation mechanism comprises: an elastically bendable driving part; an elastically bendable driven part that is provided separate from the driving part; and a linking part that connects the driving part and the driven part, and tensions and bends the driven part in accordance with bending of the driving part. The driving part and the driven part each comprise an inner coil part and an outer coil part that are bendable with respect to the axial direction, and wound parts corresponding to the inner coil part are respectively fitted to pitches between adjacent wound parts of the outer coil part.

First claim

What is claimed is:

1. A bending operation mechanism, comprising:
a driving part that is elastically bendable;
a driven part that is spaced apart from the driving part and is elastically bendable; and
a linking part that connects between the driving part and the driven part and pulls and bends the driven part in response to bending of the driving part,
wherein each of the driving part and the driven part comprises an inner coil spring and an outer coil spring that are bendable in an axial direction, and wound parts corresponding to the inner coil spring are fitted to gaps between adjacent wound parts of the outer coil spring,
wherein a wound part of the inner coil spring contacts both adjacent wound parts of the outer coil spring, and a wound part of the outer coil spring contacts both adjacent wound parts of the inner coil spring,
wherein the bending operation mechanism is configured such that when the linking part is pulled to bend the driven part, in the driven part, the gaps between the adjacent wound parts of the outer coil spring on an outer side of the bend increases, and the inner coil spring on the outer side of the bend is pushed out toward the outer side of the bend to fit in the increased gaps between the adjacent wound parts of the outer coil spring.

2. The bending operation mechanism according to claim 1 , wherein a length from a connection position of the linking part to the driving part to a base end part of the driving part is different from a length from a connection position of the linking part to the driven part to a base end part of the driven part.

3. The bending operation mechanism according to claim 2 , wherein the driving part and the driven part have different axial lengths, and
the linking part connects between tip parts of the driving part and the driven part.

4. The bending operation mechanism according to claim 3 , wherein the linking part is a cord-like member that connects positions radially displaced from centers of the driving part and the driven part, and
in response to a bending angle of the driving part being θ 1 , a bending angle of the driven part being θ 2 , an amount of displacement of the cord-like member at the driving part being r 1 , and an amount of displacement of the cord-like member at the driven part being r 2 , a relationship of θ 1 :θ 2 =r 2 :r 1 is established.

5. The bending operation mechanism according to claim 3 , wherein the linking part comprises one or more cord-like members, and
each cord-like member connects the driving part and the driven part at positions different by 180 degrees in a circumferential direction.

6. The bending operation mechanism according to claim 2 , wherein the linking part is a cord-like member that connects positions radially displaced from centers of the driving part and the driven part, and
in response to a bending angle of the driving part being θ 1 , a bending angle of the driven part being θ 2 , an amount of displacement of the cord-like member at the driving part being r 1 , and an amount of displacement of the cord-like member at the driven part being r 2 , a relationship of θ 1 :θ 2 =r 2 :r 1 is established.

7. The bending operation mechanism according to claim 2 , wherein the linking part comprises one or more cord-like members, and
each cord-like member connects the driving part and the driven part at positions different by 180 degrees in a circumferential direction.

8. The bending operation mechanism according to claim 1 , wherein the linking part is a cord-like member that connects positions radially displaced from centers of the driving part and the driven part, and
in response to a bending angle of the driving part being θ 1 , a bending angle of the driven part being θ 2 , an amount of displacement of the cord-like member at the driving part being r 1 , and an amount of displacement of the cord-like member at the driven part being r 2 , a relationship of θ 1 :θ 2 =r 2 :r 1 is established.

9. The bending operation mechanism according to claim 4 , wherein the linking part comprises one or more cord-like members, and
each cord-like member connects the driving part and the driven part at positions different by 180 degrees in a circumferential direction.

10. The bending operation mechanism according to claim 1 , wherein the linking part comprises one or more cord-like members, and
each cord-like member connects the driving part and the driven part at positions different by 180 degrees in a circumferential direction.

11. The bending operation mechanism according to claim 5 , wherein each cord-like member is formed in a spiral shape between the driving part and the driven part, and is displaced 180 degrees corresponding to connection at the positions different by 180 degrees due to the spiral shape between the driving part and the driven part.

Assignees

• Nhk Spring Co Ltd

Inventors

• Hirata Takafumi
• Hotoda Yuki
• Inaba Masahiro

Classifications

• B25J3/02

  involving a parallelogram coupling of the leader and follower units (pantographic instruments B43L13/00) · CPC title

• A61B2034/301

  for introducing or steering flexible instruments inserted into the body, e.g. catheters or endoscopes · CPC title

• B25J9/104

  with cables, chains or ribbons · CPC title

• B25J9/06

  characterised by multi-articulated arms · CPC title

• B25J18/06 Primary

  flexible · CPC title