公开(公告)号：US3829296A

公开(公告)日：1974-08-13

申请号：US26602772

申请日：1972-06-26

Applicant: TEXAS INSTRUMENTS INC

Inventor： ORNSTEIN J ,  CHAREST K ,  HANLEY R

IPC: C22C22/00 ,  B23K20/22 ,  B32B15/01 ,  C22C38/00 ,  G01K5/62 ,  G12B1/02 ,  B32B15/00

CPC classification number: B32B15/011 ,  B23K20/22 ,  H01H2037/526 ,  H01H2037/528 ,  Y10T428/12507 ,  Y10T428/12979

Abstract: THERMOSTAT METALS WHICH HAVE HIGH FLEXIVITES ON THE ORDER OF AT LEAST ABOUT 13X10**-7 FOR DISPLAYING SUBSTANTIAL FLEXING MOVEMENT IN RESPONSE TO TEMPERATURE VARIATIONS WITHIN A SELECTED RANGE BUT WHICH ARE ADAPTED TO BE RESTRAINED AGAINST ADDITIONAL FLEXING MOVEMENT WHILE BEING SUBJECTED TO MUCH HIGHER TEMPERATURES WITHOUT TENDING TO BECOME PERMANENTLY DEFORMED ARE SHOWN TO COMPRISE THREE LAYERS OF METAL BONDED TOGETHER, TWO OF THESE METAL LAYERS HAVING RELATIVE THERMAL EXPANSION PROPERTIES, MODULI OF ELASTICITY AND THICKNESSES PROVIDING THE THERMOSTAT METALS WITH THE DESIRED HIGH FLEXIVITES AND THE THIRD LAYER, PREFERABLY OF HIGH STRENGTH STEEL DISPOSED BETWEEN THE TWO OTHER LAYETS, HAVING THERMAL EXPANSION PROPERTIES INTERMEDIATE THE THERMAL EXPANSION PROPERTIES OF THE TWO OTHER LAYERS, AND HAVING MUCH GREATER STRENGTH THAN THE MATERIALS OF EITHER OF TWO TWO OTHER LAYERS. THERMOSTAT METALS CONVENTIONALLY EMBODY METAL LAYERS OF SELECTED ALLOYS WHICH HAVE BEEN ESPECIALLY DEVELOPED TO DISPLAYED VERY HIGH AND VERY LOW COEFFICIENTS OF THERMAL EXPANSION. WHEN THESE METAL LAYERS ARE BONDED TOGETHER IN WORK-HARDENED CONDITION, THE RESULTING THERMOSTAT METALS HAVING HIGH FLEXIVITES AND DISPLAY A SUBSTANTIAL OF SELECTED ALLOYS WHICH HAVE BEEN ESPECIALLY DEVELOPED CHARGES. WHILE SUCH CONVENTIONAL THERMOSTAT METALS ARE WIDELY USEFUL, IT IS FOUND THAT IN SOME APPLICATIONS, WHERE THE THERMOSTAT METALS ARE ARRANGED TO DISPLAY SUBSTANTIAL FLEXING MOVEMENT IN RESPONSE TO TEMPERATURE VARIATIONS WITHIN A SELECTED TEMPERATURE RANGE BUT ARE RESTRAINED AGAINST ADDITIONAL FLEXING MOVEMENT WHILE BEING SUBJECTED TO RELATIVELY HIGHER TEMPERATURES, THE THERMOSTAT METALS TEND TO UNDERGO A CHANGE IN THERMAL RESPONSE CHARACTERISTICS DURING USE, THAT IS, IT IS FOUND THAT STRESSES DEVELOPED IN THE THERMOSTAT METALS WHEN THEY ARE HEATED TO HIGH TEMPERATURE WHILE RESTRAINED AGAINST FLEXING MOVEMENT TEND TO CAUSE A DEGREE OF PERMANENT DEFORMATION IN THE THERMOSTAT METALS.