(under subclass 61) Subject matter wherein the passive or stationary work-shape-imposing structure has an interior wall surface which corresponds throughout its extent to a surface of revolution.
(1) Note. A die for this subclass may be skeletonized or made up of spaced segments, but its interior wall surface, wherever present, should conform to the subclass definition. See Fig. A in diagram appended to subclass 58.
(2) Note. Some examples of tube corrugating are found here.
SEE OR SEARCH THIS CLASS, SUBCLASS:
58, for an actuated tool or die in combination with fluid pressure internally of the work.
