| 摘要 |
A thermo-magnetic actuator includes a chamber within a housing; a working fluid changing phase upon heating and in the chamber; an electrical heater for heating the working fluid; a piston rod slidable between a retracted position, retracted with respect to the housing, and an extended position extending outward of the housing; a spring biasing the piston rod toward the retracted position; an electromagnet at an end of the housing; and a ferromagnetic target assembly attached to the piston rod, sliding within the housing, and attracted toward the electromagnet, when an electrical current flows through the electromagnet, to maintain the piston rod in the extended position even if electrical power is no longer applied to the heater. Preferably, the position of the piston rod is detected by the actuator and electrical current flow to the electrical heater is terminated when the piston rod is detected at the extended position. |
