Endoscope

Abstract

To prevent a bend at a connection part between an active bend part and a passive bend part from failing.SOLUTION: An endoscope comprises: an active bend part and a passive bend part that are bendable and successively arranged from the tip thereof; and a connection cylinder 50 that connects the active bend part with the passive bend part. Each of the active bend part and the passive bend part includes a plurality of joint cylinders 30, 40. To the connection cylinder 50, a coil member 60 is fixed through which an operation wire 90 for bending operation of the active bend part is inserted. In the vicinity of a coil member 60, a notch 43 is formed for enhancing the degree of freedom of rotation of a joint cylinder 40A of the passive bend part that is connected to the connection cylinder 50 and rotates.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an endoscope including a first bendable portion and a second bendable portion that can be bent.

Background Art

[0002] Conventionally, endoscopes in which an insertion portion inserted into a body cavity sequentially has an active bending portion (first bending portion) and a passive bending portion (second bending portion) from the tip side have been widely spread.

[0003] For example, Patent Document 1 discloses an endoscope configured such that the insertion portion has a gentle curvature change by making the curvature value during bending smaller as it goes from the active bending portion to the passive bending portion.

[0004] Further, Patent Document 2 discloses an endoscope in which a user can bend the active bending portion and the passive bending portion in four directions respectively by operating an operation portion.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] The active bending portion and the passive bending portion each include a plurality of joint cylinders and are connected via a connecting cylinder. Further, a coil member through which a wire for bending the active bending portion is inserted is fixed to the connecting cylinder by, for example, welding. Since the coil member is excellent in deformability and restorability, it does not inhibit bending and restoration at the connecting portion between the active bending portion and the passive bending portion.

[0007] On the one hand, as described above, when the coil member is fixed by welding, the deformation of the coil member is restricted at the welded portion. Therefore, when the joint cylinder of the active bending portion or the passive bending portion interferes with the coil member, it may prevent the bending and restoration at the connecting portion of the active bending portion or the passive bending portion. However, the endoscopes of Patent Document 1 and Patent Document 2 have not been devised to address such problems and cannot solve them.

[0008] The present invention has been made in view of such circumstances, and an object thereof is to provide an endoscope that can prevent problems from occurring in the bending at the connecting portion of the active bending portion and the passive bending portion even when the coil member is fixed and the deformation of the coil member is restricted.

Means for Solving the Problems

[0009] In the endoscope according to the present invention, a first bending portion and a second bending portion that can be bent are sequentially arranged from the tip, and in the endoscope including a connecting cylinder that connects the first bending portion and the second bending portion, the first bending portion and the second bending portion each include a plurality of joint cylinders, and a coil member through which a wire for bending the first bending portion is inserted is fixed to the connecting cylinder, and a notch for increasing the rotational freedom of a predetermined joint cylinder of the second bending portion that is connected to the connecting cylinder and rotates is formed in the vicinity of the coil member.

[0010] In the present invention, the notch is formed in the vicinity of the coil member in the predetermined joint cylinder or the connecting cylinder. By such a notch, the interference between the coil member and the predetermined joint cylinder is eliminated, or the rotation of the predetermined joint cylinder is prevented from being blocked by the coil member, and the rotational freedom of the predetermined joint cylinder is increased.

Effects of the Invention

[0011] According to the present invention, even when the coil member is fixed and the deformation of the coil member is restricted, it is possible to prevent the occurrence of a problem in the bending at the connecting portion between the active bending portion and the passive bending portion.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0013] Hereinafter, an endoscope according to an embodiment of the present invention will be described in detail with reference to the drawings.

[0014] (Embodiment 1) FIG. 1 is an external view of an endoscope 10 according to Embodiment 1 of the present invention. The endoscope 10 of the present embodiment includes an insertion portion 14 that has an imaging means and is inserted into a body cavity of a subject, an operation portion 20 that operates the insertion portion 14, and a connector portion 24 that is connected to a processor, a light source device, a gas and water supply device, etc. (not shown). The insertion portion 14 is connected to the operation portion 20 via the folding prevention portion 16, and the operation portion 20 is connected to the connector portion 24 via the universal code 25.

[0015] The universal code 25 has flexibility and includes an electric wire for sending an electric signal from the imaging means of the insertion portion 14 to the connector portion 24, a water passage through which water sent from the connector portion 24 passes, and an air passage through which air passes.

[0016] The operation portion 20 has a grip portion 205, a button 201 for receiving an instruction such as water supply or air supply from the user, and a bending knob 21 for operating the bending of the active bending portion 9 described later.

[0017] The grip portion 205 has a substantially cylindrical shape and is reduced in diameter toward the insertion portion 14. A channel inlet 22 for inserting a treatment instrument or the like is provided on the grip portion 205 closer to the insertion portion 14 side.

[0018] The insertion portion 14 has a small-diameter cylindrical shape and is configured to be bendable. The insertion portion 14 has a tip portion 13, an active bending portion 9 (first bending portion), a passive bending portion 8 (second bending portion), and a flexible portion 11 in order from the tip side.

[0019] The tip portion 13 has an imaging unit (not shown) including imaging means such as a CCD (Charge Coupled Device) and a CMOS (Complementary Metal Oxide Semiconductor), a circuit board for driving the imaging means, an observation optical system, etc. Further, the tip portion 13 has an illumination unit (not shown) including an illumination and illumination optical system for irradiating an observation target site in the body cavity.

[0020] The active bending portion 9 can be actively bent. That is, the active bending portion 9 is bent in four directions in response to the operation of the bending knob 21. On the other hand, the passive bending portion 8 is passively bent. That is, the passive bending portion 8 is bent in any of the four directions by contact with the subject. The flexible portion 11 has flexibility and can be bent.

[0021] Figure 2 is a cross-sectional view of the active bending portion 9 and the passive bending portion 8 along the axial direction of the insertion portion 14. In particular, Figure 2 shows the boundary portion between the active bending portion 9 and the passive bending portion 8.

[0022] The active bending portion 9 has a plurality of joint cylinders 30. The plurality of joint cylinders 30 are connected in a row. Each joint cylinder 30 has a substantially cylindrical shape and is pivotally attached to an adjacent joint cylinder 30 so as to be rotatable in the vertical, horizontal, left, and right directions.

[0023] Also, each joint cylinder 30 is provided with a pair of bearings 31 for receiving one rotation axis on one end side in the axial direction, and a pair of bearings 32 for receiving another rotation axis orthogonal to the one rotation axis on the other end side in the axial direction. The pair of bearings 31 and the pair of bearings 32 have a substantially disc shape with a through hole in the central portion and are extended in the axial direction of the joint cylinder 30. The plurality of joint cylinders 30 are connected such that the pair of bearings 31 and the pair of bearings 32 are alternately positioned in the arrangement direction.

[0024] The passive bending portion 8 has a plurality of joint cylinders 40. The plurality of joint cylinders 40 are connected in a row. Each joint cylinder 40 has a substantially cylindrical shape and is pivotally attached to an adjacent joint cylinder 40 so as to be rotatable in the vertical, horizontal, left, and right directions.

[0025] Also, each joint cylinder 40 is provided with a pair of bearings 41 for receiving one rotation axis on one end side in the axial direction, and a pair of bearings 42 for receiving another rotation axis orthogonal to the one rotation axis on the other end side in the axial direction. The pair of bearings 41 and the pair of bearings 42 have a substantially disc shape with a through hole in the central portion, are circumferentially offset with respect to the pair of bearings 31 and the pair of bearings 32, and are extended in the axial direction of the joint cylinder 40. The plurality of joint cylinders 40 are connected such that the pair of bearings 41 and the pair of bearings 42 are alternately positioned in the arrangement direction.

[0026] Inside the flexible portion 11, the active bending portion 9, and the passive bending portion 8, four operation wires 90 for bending the active bending portion 9 are inserted. One end of each operation wire 90 is fixed to the end portion on the tip end portion 13 side of the active bending portion 9, and the other end is connected to the bending knob 21 of the operation portion 20. The outsides of the plurality of joint cylinders 30 and the plurality of joint cylinders 40 are covered with bending rubber.

[0027] A connecting cylinder 50 is interposed between the active bending portion 9 and the passive bending portion 8. That is, the joint cylinder 30 (hereinafter referred to as joint cylinder 30A) on the passive bending portion 8 side among the plurality of joint cylinders 30 of the active bending portion 9 and the joint cylinder 40 (hereinafter referred to as joint cylinder 40A) on the active bending portion 9 side among the plurality of joint cylinders 40 of the passive bending portion 8 are connected via the connecting cylinder 50.

[0028] FIG. 3 is a cross-sectional view showing the connection state of the joint cylinder 30A, the connecting cylinder 50, and the joint cylinder 40A (predetermined joint cylinder). FIG. 3 shows an enlarged view of the portion surrounded by the broken-line circle in FIG. 2.

[0029] On the inner peripheral surface of the joint cylinder 30A, wire guides 33 for holding the operation wires 90 are provided at four locations. In the joint cylinder 30A, through holes 34 penetrating the joint cylinder 30A inside and outside are formed at four locations in order to fix the wire guides 33. The through holes 34 are provided at equal intervals in the circumferential direction of the joint cylinder 30A. Each wire guide 33 is engaged with the through hole 34.

[0030] The wire guide 33 includes a ring-shaped holding portion 331 and a column-shaped fitted portion 332 extending outward in the radial direction of the holding portion 331. The fitted portion 332 is fitted inside the through hole 34, and the operation wire 90 is inserted into the holding portion 331. Among the four wire guides 33, two opposing wire guides 33 are provided near a pair of bearings 31.

[0031] The connecting cylinder 50 has a substantially cylindrical shape, and at one end on the side of the joint cylinder 30A, a pair of bearings 51 that pivot with the pair of bearings 31 of the joint cylinder 30A are extended in the axial direction. The pair of bearings 51 have a substantially disc shape with a through hole in the central part. In the connecting cylinder 50, the axial dimension becomes smaller as it is farther from the pair of bearings 51 in the circumferential direction.

[0032] Also, on the inner peripheral surface of the connecting cylinder 50, coil members 60 for guiding the operation wire 90 are provided at four locations. The coil members 60 are provided at equal intervals in the circumferential direction of the connecting cylinder 50. For example, the coil members 60 are fixed to the inner peripheral surface of the connecting cylinder 50 by welding. That is, a welded portion 53 is interposed between the coil member 60 and the connecting cylinder 50.

[0033] Each coil member 60 has a pipe shape formed by closely winding a coil wire. Each coil member 60 extends along the axial direction of the connecting cylinder 50, and the end of the coil member 60 protrudes from the other end of the connecting cylinder 50 and reaches inside the joint cylinder 40A. The operation wire 90 is inserted through the coil member 60.

[0034] Furthermore, in the connecting cylinder 50, at the other end on the side of the joint cylinder 40A, a pair of bearings 52 that pivot with the pair of bearings 41 of the joint cylinder 40A are extended in the axial direction. The pair of bearings 52 have a disc shape with a through hole in the central part. The pair of bearings 52 are provided between adjacent coil members 60.

[0035] FIG. 4 is a perspective view showing the appearance of the joint cylinder 40A. The joint cylinder 40A has a substantially cylindrical shape, and at one end on the side of the connecting cylinder 50, the pair of bearings 41 are provided and pivot with the pair of bearings 52 of the connecting cylinder 50. Therefore, the joint cylinder 40A rotates around the axis passing through the pair of bearings 41.

[0036] The bearing 41 is flat and includes a semi-circular protruding portion 412 and a semi-circular base portion 413 having a larger diameter than the protruding portion 412. A through hole 411 is formed in the central portion. The bearing 41 is disposed slightly closer to the axial center side than the outer peripheral surface of the articulating cylinder 40A, and a guiding step 414 is formed between the base portion 413 and the outer peripheral surface of the articulating cylinder 40A. The height of the guiding step 414 becomes lower as it approaches the one end of the articulating cylinder 40A.

[0037] As described above, since the bearing 41 is disposed slightly closer to the axial center side than the outer peripheral surface of the articulating cylinder 40A, the base portion 413 protrudes slightly closer to the axial center side than the inner peripheral surface of the articulating cylinder 40A. As a result, a step (not shown) similar to the guiding step 414 is also formed between the base portion 413 and the inner peripheral surface of the articulating cylinder 40A.

[0038] Also, at the one end of the articulating cylinder 40A, four notches 43 (first notches) are formed to increase the rotational freedom of the articulating cylinder 40A. Each notch 43 has a semi-circular shape with a diameter larger than, for example, the diameter of the coil member 60.

[0039] The notches 43 are formed at intervals of two between a pair of bearings 41. When the articulating cylinder 40A is connected to the connecting cylinder 50, it is configured such that each notch 43 is disposed in the vicinity of the coil member 60 of the connecting cylinder 50. Specifically, the notches 43 are formed at positions corresponding to the coil member 60 (welding portion 53) in the circumferential direction of the articulating cylinder 40A.

[0040] Furthermore, as described above, the pair of bearings 42 are provided at the other end of the articulating cylinder 40A. The bearing 42 is flat and includes a semi-circular protruding portion 422 and a semi-circular base portion 423 having a larger diameter than the protruding portion 422. A through hole 421 is formed in the central portion. The bearing 42 is disposed slightly outward in the radial direction from the outer peripheral surface of the articulating cylinder 40A, and a step 424 is formed between the base portion 423 and the outer peripheral surface of the articulating cylinder 40A. The height of the step 424 becomes higher as it approaches the other end of the articulating cylinder 40A.

[0041] Thus, since the bearing 42 is disposed slightly radially outward from the outer peripheral surface of the articulating cylinder 40A, the base portion 423 is disposed slightly outside the inner peripheral surface of the articulating cylinder 40A. As a result, a step (not shown) similar to the step 424 is formed between the base portion 423 and the inner peripheral surface of the articulating cylinder 40A.

[0042] When the articulating cylinder 40A is connected to the connecting cylinder 50, the bearing 52 of the connecting cylinder 50 is guided by the guide step 414 of the articulating cylinder 40A and pivotally attached coaxially with the bearing 41 so as to be rotatable. Further, when the articulating cylinder 40A is connected to the adjacent articulating cylinder 40, the bearing 42 of the articulating cylinder 40A is pivotally attached to the bearing of the adjacent articulating cylinder 40 so as to be rotatable.

[0043] As described above, the coil member 60 is fixed to the inner peripheral surface of the connecting cylinder 50 by welding. Therefore, in the coil member 60, the welded portion cannot be deformed, and the freely deformable portion is limited to the end on the articulating cylinder 40A side, and the degree of freedom of deformation of the coil member 60 is greatly inferior. Accordingly, the articulating cylinder 40A pivotally attached to the connecting cylinder 50 and rotating may have its rotation inhibited due to interference with the coil member 60 (welded portion).

[0044] On the other hand, as described above, in the endoscope 10 of the first embodiment, in the articulating cylinder 40A, a notch 43 is formed in the vicinity of the coil member 60 of the connecting cylinder 50 and at a position corresponding to the coil member 60 in the circumferential direction of the articulating cylinder 40A. Therefore, when the articulating cylinder 40A rotates, it is possible to surely prevent the articulating cylinder 40A from interfering with the coil member 60. Therefore, in the endoscope 10 of the first embodiment, while surely guiding the operation wire 90 using the coil member 60 having a long natural length, it is possible to prevent problems from occurring in bending and restoring at the connecting portion of the active bending portion 9 and the passive bending portion 8.

[0045] In the above, the case where the notch 43 has a semi-circular shape has been described as an example, but the present invention is not limited thereto, and for example, it may be rectangular. In addition, in the above description, the case where four notches 43 are formed at the one end of the joint cylinder 40A has been described as an example, but the present invention is not limited thereto. The number of notches 43 may be five or more, or may be three or less. Furthermore, in the above description, the case where all four notches 43 have the same shape has been described as an example, but the present invention is not limited thereto, and they may be configured such that their respective shapes and sizes are different.

[0046] In addition, in the above description, the case where the coil member 60 is formed at the connecting portion between the active bending portion 9 and the passive bending portion 8, and the notch 43 is provided to prevent interference with the coil member 60 has been described as an example, but the present invention is not limited thereto. Needless to say, it is also applicable to the case where the coil member 60 is formed at the connecting portion between the passive bending portion 8 and the flexible portion 11.

[0047] (Embodiment 2) FIG. 5 is a cross-sectional view showing the connection state of the joint cylinder 30A, the connecting cylinder 50, and the joint cylinder 40A of the endoscope 10 according to Embodiment 2. Similar to the endoscope 10 of Embodiment 1, the joint cylinder 40A is pivotally attached to the connecting cylinder 50, and the joint cylinder 30A is also pivotally attached to the connecting cylinder 50. Further, the coil member 60 is welded to the inner peripheral surface of the connecting cylinder 50, and the coil member 60 extends to the inside of the joint cylinder 40A.

[0048] In the endoscope 10 of Embodiment 2, in the connecting cylinder 50, four notches 54 (second notches) for increasing the rotational freedom of the joint cylinder 40A are formed at the other end on the joint cylinder 40A side. Each notch 54 is, for example, a chamfered rectangle, and the dimension in the circumferential direction of the connecting cylinder 50 is larger than the diameter of the coil member 60. The notches 54 are formed at equal intervals in the circumferential direction of the connecting cylinder 50.

[0049] Each notch 54 is disposed in the vicinity of the coil member 60. Specifically, the notch 54 is formed in the axial direction of the connecting cylinder 50 from the other end on the joint cylinder 40A side at a position corresponding to the coil member 60 in the circumferential direction of the connecting cylinder 50.

[0050] As described above, since the coil member 60 is fixed to the inner peripheral surface of the connecting cylinder 50 by welding, the welded portion of the coil member 60 cannot be deformed. Therefore, the rotation of the joint cylinder 40A may be inhibited due to interference with the coil member 60.

[0051] On the other hand, as described above, in the endoscope 10 of the second embodiment, in the connecting cylinder 50, a notch 54 is formed at a position corresponding to the coil member 60 in the circumferential direction of the connecting cylinder 50. Therefore, in the coil member 60, the portion where deformation is restricted by welding is reduced. And, a wide interval can be ensured from the side edge 541 of the notch 54 on the joint cylinder 30A side to the joint cylinder 40A. Thus, when the joint cylinder 40A rotates, it does not interfere with the welded portion of the coil member 60 and can rotate without being blocked by the coil member 60. Therefore, in the endoscope 10 of the second embodiment, while surely guiding the operation wire 90 using the coil member 60 having a long natural length, it is possible to prevent problems from occurring in the bending and restoring at the connecting portion of the active bending portion 9 and the passive bending portion 8.

[0052] In the above, the case where the notch 54 is rectangular has been described as an example, but it is not limited thereto, and for example, it may have a semi-circular shape.

[0053] For parts similar to those of the first embodiment, the same reference numerals are given and detailed description is omitted.

[0054] (Embodiment 3) FIG. 6 is a cross-sectional view showing the connection state of the joint cylinder 30A, the connecting cylinder 50, and the joint cylinder 40A of the endoscope 10 according to the third embodiment. Similar to the endoscope 10 of the first embodiment, the joint cylinder 40A is pivotally attached to the connecting cylinder 50, and the joint cylinder 30A is also pivotally attached to the connecting cylinder 50. Further, the coil member 60 is welded to the inner peripheral surface of the connecting cylinder 50, and the coil member 60 extends to the inside of the joint cylinder 40A.

[0055] In the endoscope 10 of Embodiment 3, in the connecting cylinder 50, four notches 54 (second notches) are formed at the other end on the articulating cylinder 40A side to increase the rotational freedom of the articulating cylinder 40A. Each notch 54 is, for example, rectangular. The notches 54 have already been described in Embodiment 2, and a detailed description thereof will be omitted.

[0056] Also, at one end of the articulating cylinder 40A on the connecting cylinder 50 side, four notches 43 (first notches) are formed to increase the rotational freedom of the articulating cylinder 40A. Each notch 43 has, for example, a semi-circular shape. The notches 43 have already been described in Embodiment 1, and a detailed description thereof will be omitted.

[0057] As described above, since the coil member 60 is fixed to the inner peripheral surface of the connecting cylinder 50 by welding, the welded portion of the coil member 60 cannot be deformed. Therefore, there is a risk that the rotation of the articulating cylinder 40A may be inhibited due to interference with the welded portion of the coil member 60.

[0058] On the other hand, in the endoscope 10 of Embodiment 3, as described above, in the connecting cylinder 50, notches 54 are formed at positions corresponding to the coil member 60 in the circumferential direction of the connecting cylinder 50. Also, in the articulating cylinder 40A, notches 43 are formed at positions corresponding to the coil member 60 in the circumferential direction.

[0059] Therefore, the articulating cylinder 40A can rotate without interfering with the welded portion of the coil member 60 and without being blocked by the coil member 60. Therefore, in the endoscope 10 of Embodiment 3, while reliably guiding the operation wire 90 using a coil member 60 having a long natural length, it is possible to prevent problems from occurring in the bending and restoration at the connecting portion of the active bending portion 9 and the passive bending portion 8.

[0060] Parts that are the same as those in Embodiment 1 are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0061] (Embodiment 4) FIG. 7 is a cross-sectional view showing the connection state of the joint cylinder 30A, the connecting cylinder 50, and the joint cylinder 40A of the endoscope 10 according to the fourth embodiment, and FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. 7. Similar to the endoscope 10 of the first embodiment, the joint cylinder 40A is pivotally attached to the connecting cylinder 50, and the joint cylinder 30A is also pivotally attached to the connecting cylinder 50.

[0062] The endoscope 10 of the fourth embodiment includes a fixing ring 55 for fixing the coil member 60. The fixing ring 55 has a cylindrical shape, and the axial dimension of the fixing ring 55 is smaller than the axial dimension of the connecting cylinder 50. Also, the outer diameter of the fixing ring 55 is slightly smaller than the inner diameter of the connecting cylinder 50, and it is fitted inside the connecting cylinder 50. For example, the fixing ring 55 is screwed to the connecting cylinder 50 by screws 56.

[0063] Four coil members 60 are provided at four locations on the inner peripheral surface of the fixing ring 55. The coil members 60 are provided at equal intervals in the circumferential direction of the fixing ring 55. For example, the coil members 60 are welded to the inner peripheral surface of the fixing ring 55. That is, as shown in FIG. 8, a welded portion 53 is interposed between the coil member 60 and the fixing ring 55, and the outer peripheral surface of the fixing ring 55 is covered by the connecting cylinder 50. The operation wire 90 is inserted through the coil member 60.

[0064] In the endoscope 10 of the fourth embodiment, four notches 43 (first notches) are formed at one end of the joint cylinder 40A on the side of the connecting cylinder 50 to increase the rotational freedom of the joint cylinder 40A. Each notch 43 has, for example, a semi-circular shape. The notches 43 have already been described in the first embodiment, and a detailed description will be omitted.

[0065] As described above, since the coil member 60 is fixed to the inner peripheral surface of the fixing ring 55 by welding, the welded portion of the coil member 60 cannot be deformed. Therefore, there is a risk that the rotation of the joint cylinder 40A may be inhibited due to interference with the welded portion of the coil member 60.

[0066] In contrast, in the endoscope 10 of the fourth embodiment, in the joint cylinder 40A, a notch 43 is formed at a position corresponding to the coil member 60 in the circumferential direction. Therefore, the joint cylinder 40A can rotate without interfering with the welded portion of the coil member 60 and without being blocked by the coil member 60. Accordingly, in the endoscope 10 of the fourth embodiment, while reliably guiding the operation wire 90 using the coil member 60 having a long natural length, it is possible to prevent problems from occurring in the bending and restoring at the connecting portion between the active bending portion 9 and the passive bending portion 8.

[0067] For the parts similar to those of the first embodiment, the same reference numerals are given and the detailed description is omitted.

[0068] (Embodiment 5) FIG. 9 is a cross-sectional view showing the connected state of the joint cylinder 30A, the connecting cylinder 50, and the joint cylinder 40A of the endoscope 10 according to the fifth embodiment. Similar to the endoscope 10 of the first embodiment, the joint cylinder 40A is pivotally attached to the connecting cylinder 50, and the joint cylinder 30A is also pivotally attached to the connecting cylinder 50. Further, similar to the fourth embodiment, a fixing ring 55 is provided, and the coil member 60 is welded to the inner peripheral surface of the fixing ring 55.

[0069] In the endoscope 10 of the fifth embodiment, in the connecting cylinder 50, four notches 54 (second notches) for increasing the rotational freedom of the joint cylinder 40A are formed at the other end on the joint cylinder 40A side. Each notch 54 is, for example, rectangular. The notches 54 have already been described in the second embodiment, and a detailed description thereof is omitted.

[0070] Also, at one end of the joint cylinder 40A on the connecting cylinder 50 side, four notches 43 (first notches) for increasing the rotational freedom of the joint cylinder 40A are formed. Each notch 43 has, for example, a semi-circular shape. The notches 43 have already been described in the first embodiment, and a detailed description thereof is omitted.

[0071] As described above, since the coil member 60 is welded to the inner peripheral surface of the fixing ring 55, the welded portion of the coil member 60 cannot be deformed. Therefore, there is a risk that the rotation of the articulating cylinder 40A may be inhibited due to interference with the welded portion of the coil member 60.

[0072] On the other hand, in the endoscope 10 of the fifth embodiment, a notch 54 is formed in the connecting cylinder 50, and a notch 43 is formed in the articulating cylinder 40A. Therefore, the articulating cylinder 40A can rotate without interfering with the welded portion of the coil member 60 and without being blocked by the coil member 60. Therefore, in the endoscope 10 of the fifth embodiment, while reliably guiding the operation wire 90 using the coil member 60 having a long natural length, it is possible to prevent problems from occurring in the bending and restoring at the connecting portion of the active bending portion 9 and the passive bending portion 8.

[0073] Parts similar to those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

[0074] The technical features (constituent elements) described in the first to fifth embodiments can be combined with each other, and by combining them, new technical features can be formed. The embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Description of Reference Numerals

[0075] 8 Passive bending portion 9 Active bending portion 10 Endoscope 13 Tip portion 14 Insertion portion 30, 30A, 40, 40A Articulating cylinder 43 Notch 50 Connecting cylinder 54 Notch 60 Coil member 90 Operation wire

Claims

1. In an endoscope in which a first bendable portion and a second bendable portion that can be bent are sequentially arranged from the tip, a connecting cylinder that connects the first bendable portion and the second bendable portion with a space therebetween via bearings, the first bendable portion and the second bendable portion each include a plurality of joint cylinders, a coil member through which a wire for bending the first bendable portion is inserted is fixed to the connecting cylinder, a notch for increasing the rotational freedom of a predetermined joint cylinder of the second bendable portion that is connected to and rotates with the connecting cylinder is formed in the vicinity of the coil member, the position of the bearing on the first bendable portion side and the position of the bearing on the second bendable portion side are offset in the circumferential direction of the connecting cylinder, the coil member is fixed to the inner peripheral surface of the connecting cylinder and extends in the axial direction of the connecting cylinder, the endoscope, characterized in that the notch includes a first notch formed at a position corresponding to the coil member at an edge of the predetermined joint cylinder on the connecting cylinder side, and a second notch formed at a position corresponding to the coil member at an edge of the connecting cylinder on the predetermined joint cylinder side.

2. The endoscope according to claim 1, characterized in that the first notch is semi-circular with a diameter larger than the diameter of the coil member.

3. The endoscope according to claim 1, characterized in that the second notch has a chamfered rectangular shape in which the dimension in the circumferential direction of the connecting cylinder is longer than the diameter of the coil member.

Images