Curvable pipe assembly in endoscope

Claim 1

A curvable pipe assembly for an endoscope comprising: a first curvable section having a top end adapted to be coupled to a tip end part of said endoscope; a second curvable section arranged in succession with said first curvable section and having a free end; each of said first and second curvable sections comprising a plurality of articulation rings juxtaposed by pivotally supporting adjacent articulation rings at points so that said first and second curvable sections are bendable in four directions, the free end of said second curvable section being adapted to be connected to a flexible tube of said endoscope; two pairs of stay coils located in said second curvable section and having ends fastened to the connecting point of said first and second curvable sections; two pairs of pull strings disposed in said two pairs of stay coils, said pull strings having first ends fastened to the top end of said first curvable section and said pull strings adapted to extend through said flexible tube to a manual operation unit of said endoscope, movement of said pull strings effecting movement of said first curvable section in said four directions; said stay coils preventing said movement of said pull strings from moving said second curvable section in any of said four directions.