Machine for the automatic production of welded lattice girders

摘要

A lattice girder making machine has a stepwise feed mechanism for upper and lower chord wires; and a continuously operating bending mechanism for bending wire into zigzag strutting which is welded to the chord wires at a welding station. Between the bending mechanism ad the welding station the zigzag strutting slides along guides which allow the strutting alternately to contract resiliently and then to expand to accommodate the stepwise advance through the welding station. At the welding station the strutting is held at the required extension by fingers.