Patent ID: 6817540
Filing Date: 2004-11-16
Classification: G05D

Abstract:
A thermo element equipped with a thermally expanding body which is encapsulated in a tube-type case and which serves to allow a moving piston to advance toward and withdraw from the outside of the case in accordance with a change in the volume of the thermally expanding body that accompanies a variation in the temperature thereof, and a heating element which is disposed in the case and thermally affects the thermally expanding body,characterized in that the heating element has a substantially tubular shape and is disposed so as to be embedded in the thermally expanding body in a substantially central position in the case; an electrode member, which is connected to an external power supply via a terminal withdrawal portion provided at the end of the case on the opposite side to the piston, is disposed on the inner circumferential side of the heating element; a plate spring member which also serves as a heat radiation fin for radiating heat to the thermally expanding body is disposed at the circumference of the heating element between this circumference and the inside wall portion of the case, the plate spring member having a larger surface area than the heating element.