# US 2016/0249786 A1 · Passive bending section for endoscope, and endoscope > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0249786 A1 - Document ID: US20160249786A1 - Status: Published application - Kind: A1 - Application number: 15/150,965 - Filed: 2016-05-10 - Published: 2016-09-01 - Earliest claimed: 2013-12-06 - Assignees: Olympus Corporation - Applicants: Olympus Corporation - Inventors: Kenichiro SAITO; Takahiro KISHI - Web page: https://patentgrep.com/patent/US20160249786A1 ## CPC - A61B 1/0055: {Constructional details of insertion parts, e.g. vertebral elements} - A61B 1/0057: {Constructional details of force transmission elements, e.g. control wires} - G02B 23/2476: {Non-optical details, e.g. housings, mountings, supports} - A61M 25/0045: {multi-layered, e.g. coated (coating materials A61L29/08)} - A61M 25/0054: {with regions for increasing flexibility} - A61M 25/0138: {having flexible regions as a result of weakened outer material, e.g. slots, slits, cuts, joints or coils} - A61M 25/0147: {with movable mechanical means, e.g. pull wires} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} ## 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. ## Claims ### Claim at position 1 -16. (canceled) ### Claim 17 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 connected to 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. ### Claim 18 (depends on 17) The endoscope according to claim 17, wherein the second cover is made of a material different from that of the first cover. ### Claim 19 (depends on 17) The endoscope according to claim 17, wherein the first helical tube and the second helical tube are continuously and integrally formed by the helically wound thin plates. ### Claim 20 (depends on 17) The endoscope according to claim 17, 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. ### Claim 21 (depends on 17) The endoscope according to claim 17, 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. ### Claim 22 (depends on 17) The endoscope according to claim 17, 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. ### Claim 23 (depends on 22) The endoscope according to claim 22, 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. ### Claim 24 (depends on 17) The endoscope according to claim 17, wherein the second cover is superimposed so that an inner peripheral surface of a proximal end abuts on an outer peripheral surface of a distal end of the first cover in the flexible tube, and the second cover covers the distal end of the first cover. ### Claim 25 (depends on 17) The endoscope according to claim 17, 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. ### Claim 26 (depends on 17) The endoscope according to claim 17, wherein in the proximal end portion of the passive bending section, the loosely wound portion integrally connected to the flexible tube is disposed. ### Claim 27 (depends on 17) The endoscope according to claim 17, wherein in the distal end portion of the passive bending section, the loosely wound portion coupled with the active bending section via a coupling member is disposed. ### Claim 28 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 connected to 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.