Tip articulation mechanism for endoscopes

摘要

A pulling wire for tip articulation mechanism of endoscope is fitted with an overload preventing spring in the middle thereof. This spring is arranged to stretch upon more than a certain amount of tension. Elongation of the overload preventing spring absorbs any excessive tension which is exerted upon the pulling wire as a result of motion restriction of the endoscope. This spring is fabricated such that the material wire thereof is spirally coiled, and is simultaneously twisted so that forcing pressure is introduced in the spring in the direction in which the adjoining ring portions thereof are brought into pressure contact with one another it is subjected to tension.