Abstract: A flexible tube includes a helical tube having a first sparsely wound region, a closely wound region, a change region, and a second sparsely wound region. In a state where the change region is arranged between the closely wound region and the second sparsely wound region, the change region changes an unbendability such that the unbendability of the distal end portion of the third flexible portion is closer to the unbendability of the second flexible portion and the unbendability of the proximal end portion of the third flexible portion is closer to the unbendability of the fourth flexible portion.

Abstract: A flexible tube includes a first outer layer covering an outer side of a closely-wound region; a second outer layer forming a second flexible portion which is more difficult to bend than the first flexible portion; a third outer layer covering an outer side of the sparsely-wound region, and forming a third flexible portion which is as difficult to bend as the second flexible portion, or more difficult to bend than the second flexible portion; and a fourth outer layer arranged consecutively between the second and third outer layers to cover the outer side of a boundary position of the closely-wound region and the sparsely-wound region, and reducing a difference in bending difficulty/bending easiness at the boundary position.

Abstract: A flexible tube used as a part of an insertion section which defines a central axis of an insertion apparatus to be inserted into a hole, the flexible tube includes: a helical tube comprising a closely-wound region including a concave-convex portion which is provided on each of a pair of edges of a strip-shaped member elongated along a longitudinal axis, and which alternately includes convex portions and concave portions on the concave-convex portion, wherein, in a state where the strip-shaped member is spirally wound, the convex portions of the concave-convex portions facing each other along the central axis are compressed to each other; and a cylindrical outer tube which covers an outer surface of the helical tube.

Abstract: A flexible tube includes an envelope, a spiral tube and a built-in component. The spiral tube includes a first area portion and a second area portion. The spiral tube is under an initial tension throughout the overall length, and the built-in component includes a supplement area portion which supplements the elasticity of the spiral tube.

Abstract: A flexible tube includes a helical tube including a closely-wound region and a sparsely-wound region, and an outer tube covering an outer side of the helical tube. The closely-wound region includes a closely-wound portion to which a tight contact force is applied, the tight contact force allowing adjacent parts of a wire member adjacent along the longitudinal axis to become a tight contact state, a sparsely-wound portion which is arranged at a proximal side of the closely-wound portion, and a change portion which is arranged at a proximal side of the sparsely-wound portion and, has the tight contact force between the adjacent parts on the proximal side rather than the distal side along the longitudinal axis reduced more than the tight contact force of the closely-wound portion.

Abstract: A flexible tube for an endoscope includes a helical tube, a cover, and an inhibition mechanism. The inhibition mechanism enables movement of a densely wound portion to the cover in a direction of a central axis of the helical tube and inhibits movement of a loosely wound portion to the cover in the central axis direction of the helical tube.

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.

Abstract: A flexible tube includes a first outer layer covering an outer side of a closely-wound region; a second outer layer forming a second flexible portion which is more difficult to bend than the first flexible portion; a third outer layer covering an outer side of the sparsely-wound region, and forming a third flexible portion which is as difficult to bend as the second flexible portion, or more difficult to bend than the second flexible portion; and a fourth outer layer arranged consecutively between the second and third outer layers to cover the outer side of a boundary position of the closely-wound region and the sparsely-wound region, and reducing a difference in bending difficulty/bending easiness at the boundary position.

Abstract: A flexible tube used as a part of an insertion section which defines a central axis of an insertion apparatus to be inserted into a hole, the flexible tube includes: a helical tube comprising a closely-wound region including a concave-convex portion which is provided on each of a pair of edges of a strip-shaped member elongated along a longitudinal axis, and which alternately includes convex portions and concave portions on the concave-convex portion, wherein, in a state where the strip-shaped member is spirally wound, the convex portions of the concave-convex portions facing each other along the central axis are compressed to each other; and a cylindrical outer tube which covers an outer surface of the helical tube.

Abstract: A flexible tube includes a helical tube including a closely-wound region and a sparsely-wound region, and an outer tube covering an outer side of the helical tube. The closely-wound region includes a closely-wound portion to which a tight contact force is applied, the tight contact force allowing adjacent parts of a wire member adjacent along the longitudinal axis to become a tight contact state, a sparsely-wound portion which is arranged at a proximal side of the closely-wound portion, and a change portion which is arranged at a proximal side of the sparsely-wound portion and, has the tight contact force between the adjacent parts on the proximal side rather than the distal side along the longitudinal axis reduced more than the tight contact force of the closely-wound portion.

Abstract: A flexible tube includes an envelope, a spiral tube and a built-in component. The spiral tube includes a first area portion and a second area portion. The spiral tube is under an initial tension throughout the overall length, and the built-in component includes a supplement area portion which supplements the elasticity of the spiral tube.

Abstract: A flexible tube includes a helical tube having a first sparsely wound region, a closely wound region, a change region, and a second sparsely wound region. In a state where the change region is arranged between the closely wound region and the second sparsely wound region, the change region changes an unbendability such that the unbendability of the distal end portion of the third flexible portion is closer to the unbendability of the second flexible portion and the unbendability of the proximal end portion of the third flexible portion is closer to the unbendability of the fourth flexible portion.

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.

Abstract: A flexible tube for an endoscope includes a helical tube, a cover, and an inhibition mechanism. The inhibition mechanism enables movement of a densely wound portion to the cover in a direction of a central axis of the helical tube and inhibits movement of a loosely wound portion to the cover in the central axis direction of the helical tube.

Abstract: A flexible tubular portion for an endoscope having a central axis includes a spiral tube, an outer layer covering the outside of the spiral tube, and an inhibiting portion. The spiral tube includes, along the longitudinal direction of the central axis, a closely wound portion to which an initial tension is applied, and sparsely wound portions provided on the distal side and the proximal side of the closely wound portion. The inhibiting portion inhibits the movement of at least a part of the sparsely wound portions relative to the outer layer in the longitudinal direction of the spiral tube.

Abstract: A flexible tubular portion for an endoscope having a central axis includes a spiral tube, an outer layer covering the outside of the spiral tube, and an inhibiting portion. The spiral tube includes, along the longitudinal direction of the central axis, a closely wound portion to which an initial tension is applied, and sparsely wound portions provided on the distal side and the proximal side of the closely wound portion. The inhibiting portion inhibits the movement of at least a part of the sparsely wound portions relative to the outer layer in the longitudinal direction of the spiral tube.

Abstract: A first bendable section which can be bent in an arbitrary direction and a second bendable section which can be bent in the bending direction of this first bendable section are provided at the tip end side of an insertion portion. A balloon which is inflated/contracted by feed/discharge of a fluid is provided in this second bendable section so that hardness of this second bendable section can be varied and insertion work into a curved portion is facilitated.

Abstract: According to the present invention, when processing shafts in a centerless grinding machine, engagement between the shafts is prevented without rearranging the shafts, and thus outer circumferential faces of the shafts can be precisely processed. A shaft 12 is used in a hydrodynamic bearing device, and includes a cylindrical column formed with an outer circumferential face 12a forms a hydrodynamic radial bearing portion, a tapped hole 12j that is formed at a first end of the cylindrical column, and a first projecting portion 12b formed at a second end of the cylindrical column. When the first end and the second end of the shafts 12 are arranged side by side in an axis direction, the first projecting portion 12b of the shaft 12 can not interfere with the tapped hole 12j of the other shaft 12.

Abstract: An insertion apparatus includes: an introducing duct including; insertion portion cover portion for covering an insertion portion extending from a distal side portion of a handling portion constituting an endoscope; and a spiral duct which is disposed on an inner circumferential surface side of the insertion portion cover portion, and has on a circumferential surface of the spiral duct, a propulsion power generating portion for applying a propulsion power for introducing the insertion portion into a deep portion in a body cavity, to the insertion portion covered by the insertion portion cover, and a rotating device comprising a rotating portion for rotating the spiral duct equipped to the introducing duct.

Abstract: An endoscope capable of being autoclaved in accordance with the present invention includes an insertion unit, an internal endoscope space, and contents. The insertion unit has a soft member, which is made of a soft polymeric material, as at least part of a casing thereof. The internal endoscope space includes the internal space of the insertion unit that is formed at a first sealing level at which the internal space is sealed in a watertight manner relative to an outside. The contents include at least one hermetically sealed unit composed of a plurality of airtight partition members and formed at a second sealing level higher than the first sealing level by joining the meeting portions of the airtight partition members using an airtight joining material. All or part of the airtight partition members is stowed in the internal endoscope space.