Abstract: A spiral tube is provided rotatably around an insertion axis of the insertion portion by a driving force of a driving unit, and includes a first cylindrical member formed into a cylindrical shape, a second cylindrical member provided at another end, and formed into a cylindrical shape, an outer layer tube that has one end fixed to the first cylindrical member, and has an longitudinal axis, an inner layer tube that has one end fixed to the second cylindrical member, and is covered with the outer layer tube so that the outer layer tube is slidable in a direction along the longitudinal axis, and a holding member provided on the outer layer tube, and configured to restrict movement of the outer layer tube with respect to the inner layer tube to a predetermined range, and to hold the inner layer tube in the outer layer tube.

Abstract: A spiral tube is provided rotatably around an insertion axis of the insertion portion by a driving force of a driving unit, and includes a first cylindrical member formed into a cylindrical shape, a second cylindrical member provided at another end, and formed into a cylindrical shape, an outer layer tube that has one end fixed to the first cylindrical member, and has an longitudinal axis, an inner layer tube that has one end fixed to the second cylindrical member, and is covered with the outer layer tube so that the outer layer tube is slidable in a direction along the longitudinal axis, and a holding member provided on the outer layer tube, and configured to restrict movement of the outer layer tube with respect to the inner layer tube to a predetermined range, and to hold the inner layer tube in the outer layer tube.

Abstract: A tube for insertion device arranged on an outer periphery of an insertion section in an insertion device configured to be inserted into a subject and rotatable around a longitudinal axis of the insertion section includes a tapered portion formed in a distal end portion in the insertion section and having an outer diameter decreasing toward a distal end of the insertion section, and a stiffening portion provided at a distal end of the tapered portion and having a higher rigidity than a rigidity of the distal end of the tapered portion.

Abstract: On an inner peripheral surface of an assistance tool of an insertion device, a sliding surface extends from an assistance tool proximal surface toward a distal side, and when the assistance tool attached to an insertion section rotates, the sliding surface slides on a supporting surface around a longitudinal axis. A flange portion of the insertion section includes an opposed surface opposed to the assistance tool proximal surface with a gap when the assistance tool is attached to the insertion section. In a part where the assistance tool proximal surface is opposed to the opposed surface, a proximal end of an outer peripheral surface of the assistance tool does not form a step relative to the flange portion.

Abstract: On an inner peripheral surface of an assistance tool of an insertion device, a sliding surface extends from an assistance tool proximal surface toward a distal side, and when the assistance tool attached to an insertion section rotates, the sliding surface slides on a supporting surface around a longitudinal axis. A flange portion of the insertion section includes an opposed surface opposed to the assistance tool proximal surface with a gap when the assistance tool is attached to the insertion section. In a part where the assistance tool proximal surface is opposed to the opposed surface, a proximal end of an outer peripheral surface of the assistance tool does not form a step relative to the flange portion.

Abstract: An insertion instrument includes an insertion section extending from a proximal side to a distal side along a longitudinal axis, and the insertion section includes an assistance tool attaching portion to which an assistance tool is attached. A dimension index indicating a dimension from a distal end of the insertion section is provided on an outer surface of the insertion section. A position index provided at a reference position, which is spaced from a proximal end of the assistance tool attached to the assistance tool attaching portion at a predetermined dimension to the proximal side, on the outer surface of the insertion section, the position index being an index indicating a position is the reference position.

Abstract: An endoscope of an embodiment includes: a distal end rigid member made of resin; a channel tube connecting member which has a distal end side fitted and fixed in the distal end rigid member and is formed in a tubular shape using a conductive member, and which includes a stepped portion on a part of an outer circumferential surface in a longitudinal direction; and a bending piece member which is formed in a tubular shape using a conductive member and arranged just behind a rear end side of the distal end rigid member, and which has a protruding portion protruding and elastically-deformed toward an inner circumferential surface side, wherein when the bending piece member is fixed to the distal end rigid member with the channel tube connecting member being housed inside thereof, the protruding portion contacts the outer circumferential surface of the channel tube connecting member to establish conduction.