PURPOSE: To open/close a gate valve at specific temperatures through simple structure by energizing the gate valve slidable on the upper face of a fixed board having an opening in one direction through a spring made of shape- memory alloy and in the other direction through a bias spring.
CONSTITUTION: When ambient temperature is low, blades 30 of a gate valve 28 stops between slits 24, 24 because the spring constant of an actuator 38 is low and the force of a bias spring 40 is stronger than the force of the actuator 38, so as to open an opening 26. When temperature rises over the opening temperature of shape-memory alloy, spring constant of the actuator spring 38 is increased through shape-memory effect and the gap between a bracket 32a and a supporting member 36a is enlarged thus sliding the blade 30 of the gate valve 28. Consequently, the slit 24 of the opening 26 is covered with the blade 30 thus closing the gate valve 28.
AOYAMA HITOSHI
OKAZAKI YOSHIHISA
GENBAN KOEI
