. . . "BRIEF DESCRIPTION OF THE DRAWINGS In the drawings forming a part of this application and in which like parts are designated by like reference numerals throughout the same, FIG. 1 is a view, mainly in section, of a can necking machine constructed in accordance with the invention; FIG. 2 is a view, partly in section, of the internal roller mechanism, rotated from the position shown in FIG. 1; FIG. 3" .