Thermally responsive switch

A thermally responsive switch comprising:

• (a) first and second metallic members serving as two electrical terminals electrically insulated from each other;
• (b) a fixed contact arm having one end electrically conductively secured to the first metallic member and the other end to which a fixed contact is secured, the fixed contact arm including a first electrically conductive support piece to which the fixed contact is secured, a second electrically conductive support piece secured to the first metallic member, a ceramic or other insulator insulatively coupling the first and second support pieces, and a conductive heating element provided along the insulator for electrically connecting the first and second support pieces;
• (c) a support arm electrically conductively secured at one end thereof to the second metallic member;
• (d) a thermally responsive element mounted on the other end of the second metallic member in cantilever relation, the thermally responsive element having a free end on which a movable contact is carried and a dish-shaped portion formed in a suitable portion thereof for a snap-acting reversing operation;
• (e) first and second beam members held on a suitable stationary member with the support arm interposed therebetween;
• and
• (f) a calibration strip substantially integral with the first beam member to be extended therefrom and having a portion where the same is bendable, the calibration strip being interposed between the support arm and the second beam member into a wedge structure so that the calibration strip is slidably adjacent to one side of the support arm and so that the free end thereof is slidably engaged with the second beam member, whereby the support arm suffers the bending deformation, the amount of which deformation corresponds to that of the bending deformation of the calibration strip with slidable movement, such that the contact pressure between the movable and fixed contacts are set.