| 摘要 |
A machine and method for forming line pipe is disclosed wherein small diameter roll elements not exceeding five times the thickness of the blank form a tube. The roll elements positioned in a pyramid roll assembly are dynamically adjustable toward and away from each other to provide different size line pipe, or similar tubular articles. The segments of the upper roll elements are mounted on cantilever arms, the leading edge of blank being deflected against the upper curved surface of the arms during the final stages of forming. The deflection is maintained within the elastic recovery limit of the metal. A rigid frame mounts the cantilever arm and other components. The frame includes a plurality of vertical bed plates and corresponding upper frame plates and cross tie members. A pusher mechanism pushes the sheet blank through the pyramid roll assembly. A multi-walled tube may be formed by providing the required additional length to the blank and continuation of the forming beyond 360 DEG . The blank is confined between idler rollers on the frame structures during forming. Special roller handling assemblies are provided for loading the blank and for unloading the finished tube from the machine.
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