(under subclass 253.1) Apparatus comprising closed chamber means, or cover or closure means therefor, or structure for supporting or axially moving the closed chamber means.
SEE OR SEARCH THIS CLASS, SUBCLASS:
263, for the same plus a nonaxial component of container movement.
SEE OR SEARCH CLASS
220, Receptacles, appropriate subclasses for a receptacle not specially adapted to use in extrusion apparatus.