Abstract: a temperature switch is disclosed which has a bimetal disc being inversely deformed between a concave shape and a convex shape according to a temperature change. A bottom portion including the outer periphery of a casing of the temperature switch is in a plane shape. At an inner position of the outer periphery of the bottom portion, a protruding line for supporting an outer peripheral portion of the disc is formed. When the temperature switch is used in such a way that the outer surface of the bottom portion is in contact with a test subject, since heat is transferred from both iner and outer side walls of the protruding line to the disc, the delay of thermal transfer can be reduced.

Abstract: A heat sensitive actuator including a casing; a thermal expansion fluid contained in the casing; a piston rod inserted from an opening of the casing into the fluid and adapted to be moved outside the casing by thermal expansion of the fluid; a shoulder formed on an inner circumference of the casing at an opening portion thereof, which shoulder has a conical shape tapering inward of the casing; a plug formed of an elastic material such as rubber for sealing the fluid, which plug has a through-hole for allowing insertion of the piston rod; and an intermediate ring inserted in a part of the through-hole of the plug and interposed between an inner circumference of the plug and the outer circumference of the piston rod. The plug is forced into the shoulder to be elastically compressed and thereby radially urge an outer circumference of the piston rod. A contact area between the plug and the piston rod can be reduced by providing the intermediate ring to thereby reduce a frictional resistance of the piston rod.