A method and system for constructing, designing, and using a family of logic circuits based on methods of interconnecting transistors. A powder mixture is disposed within the opening. This structure can thus alleviate excessive heating around the aperture, and allow the heating coil to produce a high output power for a long duration of time even when an inwardly concaved pan is used. The blade member contains a slitter blade and overlies the locking member which is nested therewith. An intake chamber serving as part of a purified-air chamber formed between the funnel portion and the cleaner case is formed at least below the main tube portion.