Patent ID: 8906002

Claim:
A bending joint mechanism comprising a joint section, the joint section comprising: a shaft section which has an arc-shaped first rotation guide portion around a first rotation center and which has an axis that intersects at right angles with the axis of the first rotation center; an actuating section having an arc-shaped second rotation guide portion around a second rotation center, the second rotation guide portion coming in rolling contact with the first rotation guide portion at a proximal end portion thereof; a coupling member which is rotatably coupled at a distal end portion thereof to the second rotation center and which is rotatably coupled at a proximal end portion thereof to the first rotation center; and a rod section which is provided translatability relative to the shaft section in the axial direction of the shaft section and which is coupled at a distal end portion thereof to a position other than the first rotation center and which translates in the axial direction of the shaft section in response to a driving force, wherein the bending joint mechanism turns the second rotation guide portion around the first rotation center along the first rotation guide portion via the coupling member together with the translating of the rod section to bend the actuating section relative to the shaft section, and the rod section has an elastic portion which is elastically deformable in directions other than the axial direction of the shaft section.