Patent ID: 8114098

Claim:
An insertion apparatus for an endoscope, the apparatus comprising: a tubular body configured to be inserted into a surgical tool insertion channel of the endoscope; and a wire member configured to be inserted into an inside cavity of the tubular body, wherein the tubular body comprises: a distal end coil which is provided in the distal end side of the tubular body; a proximal end coil which is provided at the proximal end of the distal end coil, and has an inside diameter smaller than an inside diameter of the distal end coil; and an inside diameter changed member which is provided between the proximal end of the distal end coil and the distal end of the proximal end coil, and comprising a reducing inside diameter to connect the proximal end of the distal end coil and the distal end of the proximal end coil such that the reducing inside diameter progressively reduces from a proximal end side of the distal end coil to a distal end side of the proximal end coil, wherein the inside diameter changed member has a tapered-shape with the distal end side length L determined by a thickness value H and the bending radius R obtained by the insertion section configured to be bent to a maximum, and the thickness value H is obtained by subtracting the thickness of the distal end coil from the thickness of the proximal end coil.