| 20110072875 | MANUFACTURING APPARATUS AND METHOD OF SPIRAL DUCT INCLUDING ELBOW - Provided is a manufacturing method of a spiral duct including an elbow. The manufacturing method includes: bending projecting wave portions of metal plate members upward by a ball caster, the metal plate members being cut in such a manner that a straight lines and waves are formed; transferring the metal plate members using a pair of transfer rollers which are rotated by a first motor installed in a manufacturing apparatus of a spiral duct including an elbow; pressing a single folded portion and a double folded portion of the metal plate members using upper and lower pressing rollers while the transferred metal plate members are rolled into a circular shape by a joint jig; and cutting the elbow formed by the manufacturing apparatus using upper and lower cutters. According to the invention, an elbow curved at a gentle angle can be formed, and the projecting wave portions of the metal plate members are bent so as to form the elbow. Therefore, a fluid can smoothly flow along the curved portion of the elbow. Further, as the elbow is formed by consecutive processes, it is possible to increase productivity. | 03-31-2011 |
