Abstract: A blocked end portion of a cylinder is provided closer to a distal end side in a direction of insertion of the piston into the cylinder than a minimum diameter portion. The blocked end portion includes a minimum diameter uniform portion which has the same inside diameter as the minimum diameter portion and a partial diameter increased portion which has an inside diameter that is increased as compared to the inside diameter of the minimum diameter portion.

Abstract: A blocked end portion of a cylinder is provided closer to a distal end side in a direction of insertion of the piston into the cylinder than a minimum diameter portion. The blocked end portion includes a minimum diameter uniform portion which has the same inside diameter as the minimum diameter portion and a partial diameter increased portion which has an inside diameter that is increased as compared to the inside diameter of the minimum diameter portion.

Abstract: An endoscope bending device includes an operation wire which includes a wire proximal end movably provided in an inner peripheral groove of a pulley, and a wire distal end connected to a bending section, the operation wire extending into an endoscope insertion section after being wound around an outer peripheral groove or the inner peripheral groove in a neutral condition in which the bending section is not bent. The endoscope bending device includes a slack absorbing portion which is configured to absorb the slack of the operation wire by moving the wire proximal end of the operation wire in the inner peripheral groove in a direction opposite to a discharging direction of the operation wire during the operation of discharging the operation wire from the neutral condition.