EXTENSION TUBE FOR VACUUM CLEANER OF REFLUX TYPE, ITS MOLDING METHOD, AND ITS MOLDING DEVICE

摘要

PROBLEM TO BE SOLVED: To mold an extension tube of an adequate shape by preventing a core for a passage on a reflux side from being shifted. SOLUTION: A main body 5 of the tube is formed by an outer cylinder 26 and an inner cylinder 27 provided inside of this outer cylinder 26. The passage 30 on the reflux side enclosed by the inner surface of the outer cylinder 26 and the outer surface of the inner cylinder 27 and a passage 31 on the suction side inside the inner cylinder 27 are formed. A through-hole 48 provided to communicate the passage 30 with the outside and closed by a blank lid 49 is formed on the outer cylinder 26. COPYRIGHT: (C)2004,JPO