A wire loop type instrument for an endoscope that uses an elastic wire formed from a stranded wire bent into a U-shape and looped at the rear of the U-shaped bent portion. Each strand of the stranded wire has a non-circular cross-sectional configuration in which the strand is more resistant to bending in other directions than in a direction toward the center of the elastic wire. The stranded wire is formed by twisting together a plurality of strands each having a circular cross-section. The stranded wire is passed through a die with a hole having a smaller diameter than that of the stranded wire, thereby compression-deforming each strand into a non-circular cross-sectional configuration. A composite stranded wire may be used as the elastic wire, which is formed by twisting together a plurality of stranded wires each formed from a plurality of strands twisted together.
Endoscopic biopsy forceps that allow for smooth action of drive levers to ensure that forceps cups formed integral with the drive levers will positively open and close. Parallel grooves are formed in the drive levers in a direction perpendicular to the longitudinal axis of a support shaft and connecting members for coupling a manipulating wire and the drive levers are coupled to the drive levers within the parallel grooves.
