Abstract: An assist assembly for propulsion of a tip device of an endoscope in a body cavity includes an attachment sleeve and a support sleeve. A deformable circulation device is disposed to extend over inner and outer surfaces of the support sleeve, for endlessly moving in an axial direction of the tip device. Plural rollers are disposed on the support sleeve in a rotatable manner, for pressing an inner surface of the circulation device. An alignment projection is formed on the inner surface of the circulation device to project at a height L1. A location offset prevention groove is formed in the rollers at a depth L2, for receiving the alignment projection, and satisfying a condition L1?L2, to prevent location offset of the circulation device from the rollers. Drive wheels tension the circulation device in cooperation with the rollers by deforming the alignment projection in the location offset prevention groove.

Abstract: An insertion assisting device includes a rotary body formed in a toroidal shape, and a support and drive unit that rotatably supports and rotates the rotary body. The support and drive unit has two supports, a first support and a second support. The first support is formed in a substantially cylindrical shape, and rotatably supports the rotary body. The second support is formed in a substantially triangular tubular shape, is arranged inside the first support, and supports driving gears that transmit a driving force to the rotary body. The second support is shorter than the first support, and is arranged so that front and rear end portions thereof are located inside front and rear end portions of the first support.

Abstract: A propelling device includes a traveling body that rotates in a state of being brought into contact with an inner wall of an alimentary canal, an external cylinder around which the traveling body is wound, and a mounting cylinder on which a tip end portion of an endoscope is mounted. Three driven rollers are rotatably attached to the external cylinder. The traveling body is pinched between the driven rollers and driving gears. As the driving gears rotate, the traveling body travels in a circulating manner. A rotating shaft of the driven roller located at the center among the three driven rollers is held by a shaft hole that is made long in a gear arrangement direction in which the driving gears are disposed side by side.

Abstract: An insertion assisting device includes a rotary body in the form of toroid, and a support and drive part for supporting the rotary body in a rotatable manner and rotating it. The support and drive part has an approximately cylindrical supporting member for supporting the rotary body in a rotatable manner. The rotary body is provided with a convex portion for increasing the thickness to improve the strength thereof. A concave portion having a shape corresponding to the shape of the convex portion is formed on a portion of a front end surface of the supporting member, which is made in contact with the convex portion. The concave portion prevents the rotary body from stopping rotating, which may be caused by point contact between the convex portion and the supporting member.

Abstract: An assist assembly for propulsion of a tip device of an endoscope in a body cavity includes an attachment sleeve and a support sleeve. A deformable circulation device is disposed to extend over inner and outer surfaces of the support sleeve, for endlessly moving in an axial direction of the tip device. Plural rollers are disposed on the support sleeve in a rotatable manner, for pressing an inner surface of the circulation device. An alignment projection is formed on the inner surface of the circulation device to project at a height L1. A location offset prevention groove is formed in the rollers at a depth L2, for receiving the alignment projection, and satisfying a condition L1?L2, to prevent location offset of the circulation device from the rollers. Drive wheels tension the circulation device in cooperation with the rollers by deforming the alignment projection in the location offset prevention groove.

Abstract: A self-propelling device includes a drive unit and a toroid unit supported thereabout. The toroid unit includes a track structure of a toroid shape and a roller support sleeve inside the track structure. Three belt portions are provided in the track structure with high rigidity. The drive unit includes an inner sleeve for mounting on an introducer of an endoscope, and an outer sleeve supported around the inner sleeve. An inner surface of the roller support sleeve and an outer surface of the outer sleeve extend triangularly. Drive wheels are disposed upstream and downstream of respectively flat portions of the outer sleeve. Two follower rollers are disposed on respectively each of flat portions of the roller support sleeve. The drive wheels and follower rollers nip the belt portions of the track structure to move the track structure endlessly.

Abstract: A propelling device includes a traveling body that rotates in a state of being brought into contact with an inner wall of an alimentary canal, an external cylinder around which the traveling body is wound, and a mounting cylinder on which a tip end portion of an endoscope is mounted. Three driven rollers are rotatably attached to the external cylinder. The traveling body is pinched between the driven rollers and driving gears. As the driving gears rotate, the traveling body travels in a circulating manner. A rotating shaft of the driven roller located at the center among the three driven rollers is held by a shaft hole that is made long in a gear arrangement direction in which the driving gears are disposed side by side.

Abstract: An insertion assisting device includes a rotary body in the form of toroid, and a support and drive part for supporting the rotary body in a rotatable manner and rotating it. The support and drive part has an approximately cylindrical supporting member for supporting the rotary body in a rotatable manner. The rotary body is provided with a convex portion for increasing the thickness to improve the strength thereof. A concave portion having a shape corresponding to the shape of the convex portion is formed on a portion of a front end surface of the supporting member, which is made in contact with the convex portion. The concave portion prevents the rotary body from stopping rotating, which may be caused by point contact between the convex portion and the supporting member.

Abstract: An insertion assisting device includes a rotary body formed in a toroidal shape, and a support and drive unit that rotatably supports and rotates the rotary body. The support and drive unit has two supports, a first support and a second support. The first support is formed in a substantially cylindrical shape, and rotatably supports the rotary body. The second support is formed in a substantially triangular tubular shape, is arranged inside the first support, and supports driving gears that transmit a driving force to the rotary body. The second support is shorter than the first support, and is arranged so that front and rear end portions thereof are located inside front and rear end portions of the first support.

Abstract: A self-propelled device nips an endless belt between a worm wheel and a driven roller. The endless belt is circulated by rotating the worm wheel, and thereby an insertion section of an endoscope advances and retreats inside a body cavity. The driven roller has a width larger than the worm wheel, and is provided with a pair of flanges at both ends. The worm wheel is disposed between the pair of flanges. When the endless belt is nipped between the worm wheel and the driven roller, the endless belt is deformed by the pair of flanges.