Composite thermostatic materials and thermostats made therefrom

Claim 1

A COMPOSITE THERMOSTATIC MATERIAL OF SUBSTANTIALLY INVARIABLE RESISTIVITY AND FLEXIVITY, COMPRISING AT LEAST FOUR NONBRITTLE LAYERS OF METALLURGICALLY BONDED METALS HAVING A TOTAL THICKNESS IN THE RANGE OF APPROXIMATELY .003 TO .125 INCH, FIRST AND SECOND LAYERS OF WHICH ARE COMPOSED OF METALS HAVING CAMPARATIVELY HIGHER AND LOWER COEFFICIENTS OF THERMAL EXPANSION RESPECTIVELY TO PROVIDE FOR FLEXING IN RESPONSE TO TEMPERATURE CHANGE, A THIRD ELECTRICAL-SHUNT LAYER LOCATED ADJACENT TO AND IN BONDED CONTACT WITH SAID SECOND LAYER AND COMPOSED OF A METAL WHICH HAS A CAMPARATIVELY LOW ELECTRICAL RESISTIVITY RELATIVE TO THAT OF THE FIRST LAYER AND WHICH IS COMPATIBLE THEREWITH SO THAT ANY SUBSTANTIAL DIFFUSION THEREBETWEEN IS ABSENT, SAID SHUNT LAYER BEING INCOMPATIBLE WITH THE FIRST LAYER AS REGARDS DIFFUSION, AND A FOURTH LAYER SANDWICHED BETWEEN THE FIRST AND THIRD LAYERS IN BONDED CONTACT WITH EACH AND COMPOSED OF A MATERIAL WHICH IS COMPATIBLE WITH SAID FIRST AND THIRD LAYERS AND FORMING A DIFFUSION-BARRIER LAYER THEREBETWEEN, THE THICKNESS OF THE FOURTH LAYER BEING NOT MORE THAN APPROXIMATELY 5% OF SAID TOTAL THICKNESS.