摘要 |
A method and apparatus for the continuous manufacture of reinforced, spirally wound pipe having a generally smooth inner wall produced from an elongated flat sheet of ductile material, such as galvanized steel, and one or more narrow strips of ductile material. The sheet and strips are situated in rolls located at the entry end of a rolling apparatus which is constructed to form one longitudinal, generally trapezoidal reinforced impression in the sheet corresponding to each of the narrow strips. In the process of forming the impressions, rolling stands in the rolling apparatus first fashion a longitudinal, generally rectangular channel in the sheet corresponding to each strip as the sheet progresses through the rolling apparatus. At the same time, the strips are shaped into reinforcement elements having an extended, continuous portion and splayed legs extending outwardly from the edges of the continuous portion. After formation, each strip is inserted into its respective channel and the channel closed about the strip to form the trapezoidal impression. The reinforced sheet is then curled into adjacent, helical convolutions which are joined with an appropriate seam.
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