Patent ID: 8512230

Claim:
An endoscope comprising: a drive unit configured to form one of first and second main body portions to be attached to and detached from each other; an insertion portion including a bendable bending portion, which is configured to form the other of the first and second main body portions; a first shaft portion including a terminal end portion and a proximal end portion, the proximal end portion of the first shaft portion being supported by the first main body portion rotatably about a central axis of the first shaft portion; a first coupling provided at the terminal end portion of the first shaft portion; a convex engaging portion which is provided in the first coupling and which includes a distal end and a base end and extends from the distal end to the base end in a radial direction of the first shaft portion; a second shaft portion including a terminal end portion and a proximal end portion, the proximal end portion of the second shaft portion being supported by the second main body portion rotatably about a central axis of the second shaft portion; a second coupling provided at the terminal end portion of the second shaft portion; a concave engaging portion which is provided in the second coupling and extends in a radial direction of the second shaft portion, wherein the convex and concave engaging portions, before engaging each other, include basic positions where the longitudinal directions of the convex and concave engaging portions correspond to an attachment and detachment direction of the first and second main body portions and, wherein the convex and concave engaging portions are insertable into and removable from each other, the convex engaging portion is being configured to be slidably inserted into and removed from the concave engaging portion along the longitudinal direction of the concave engaging portion; a drive portion configured to rotate one of the first and second shaft portions; a bending mechanism configured to bend the bending portion by a rotation of the other of the first and second shaft portions, and a pair of guide members which is provided on the second main body portion and configured to provide a guide so as to locate the convex and concave engaging portions on the basic positions and which includes a pair of insert guide surfaces opposed to each other and configured to slide the convex engaging portion and a pair of remove guide surfaces opposed to each other and also configured to slide the base portion of the convex engaging portion, wherein; the pair of insert guide surfaces are formed so that a distance between the pair of insert guide surfaces becomes smaller towards a direction in which the convex engaging portion is attached form the basic position to the concave engaging portion, and the pair of remove guide surfaces are formed so that a distance between the pair of remove guide surfaces becomes smaller towards a direction in which the convex engaging portion engaged with the concave engaging portion is removed to the basic position.