Upset of bent wire/tube for fabrication of in-plane bent sheet metals with extremely large breadth and small bending radius

This paper presents a new method for fabrication of a ring/coil of in-plane bent sheet metal using a wire/tube as a raw material. The method conducts upset of a wire/tube bent by a coiling process. The coiling process bends a circular wire/tube into a ring/coil, and the upset process compresses it into a ring/coil with extremely flattened cross-section and small bending radius, which was difficult to obtain by conventional processes. The breadth-to-thickness ratio reached 6.0 and the outer radius-to-breadth ratio decreased to 1.7. When the method is applied for coils, the fabricated coils would be used as joints in a surgical manipulator.