摘要 |
Methods and apparatus for milling a flat surface on a large scale assembly, such as the horizontal joint surface of the outer structure of a steam turbine, are disclosed. In a preferred embodiment, lateral and longitudinal drive means are installed on a lower base assembly which is specifically adapted to be mounted and leveled by engaging portions of the structure to be machined. Sliding platforms are engaged with drive means, and a milling head is mounted to the platforms to provide the capability to move the milling head both laterally and longitudinally along the surface to be machined. In a preferred embodiment, the milling head is affixed to a platform that permits indexing the milling head to a position where it may extend beyond the maximum travel of the drive means and thereby machine the corners or otherwise inaccessible areas of the structure.
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