| 摘要 |
PURPOSE:To enable the synchronous motion of working part in a short time by expanding and contracting a bellows on the heating of a thermal expansion liquid for actuating the working part. CONSTITUTION:A thermal expansion liquid such as alcohol 'A' generating vapor pressure on heating and giving a phase change to a liquid state on cooling, is sealed in a bellows case 2. When an electrode 9 has been applied with an electric current, PTC heater gives heat and alcohol 'A' vaporizes. A bellows 4 elongates due to vapor pressure and furthermore a working rod 7 is shifted downward. Consequently, a valve 12 moves downward against the energized force of a coil spring 18 and an open/close valve 10 is kept open. When the electrode 9 has been made electrically off, alcohol 'A' is cooled and said valve 10 turns to a closed condition.
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