Temperature compensated fluid level sensor

Claim 2

A sensor device comprising: a housing member defining a chamber; a tip member adapted for being exposed to a fluid, said tip member secured to said housing and forming a closure for said chamber and to prevent fluid entrance into said chamber; a heat conductive member within said chamber having a greater heat transfer capability than said tip member; heater means within said chamber having first and second spaced apart portions, said first portion in heat conductive relationship to said heat conductive member within said chamber, said second portion in heat conductive relationship to said tip member; and first and second heat responsive means having substantially similar characteristics of thermal deflection, said first and second heat responsive means in heat conductive relationship to said first and second spaced apart portions, respectively, and each having a free end adapted for mutual engagement only when the temperature difference between said first and second spaced apart portions of said heater means exceeds a predetermined level, said temperature difference resulting from a difference in rates of heat transfer of said heat conductive member and said tip member.

Claim 3

A sensor device according to claim 1 wherein said heater means within said chamber is an electrical resistive element.

Claim 4

A sensor device according to claim 1 wherein said heat conductive member within said chamber is electrically conductive.

Claim 5

A sensor device according to claim 1 wherein said tip member is electrically conductive.

Claim 6

A sensor device according to claim 1 wherein said heat responsive means are bimetallic members.

Claim 7

The sensor device according to claim 5 wherein each of said first and second bimetallic members has a contacting portion of noble metal affixed thereto.

Claim 8

A sensor device according to claim 5 wherein said bimetallic members have a high expanding side of an alloy of nickel-chromium-iron and a low expanding side of an alloy of nickel-iron and wherein the differential in coefficients of thermal expansion between said high and low expanding sides is appreciably greater at from about 0*F to about 150*F than from about 400*F to about 600*F.

Claim 9

A sensing apparatus comprising a sensor device comprising: a housing member defining a chamber; a tip member adapted for being exposed to a fluid, said tip member secured to said housing and forming a closure for said chamber and to prevent fluid entrance into said chamber; a heat conductive member within said chamber having a greater heat transfer capability than said tip member; heater means within said chamber having first and second spaced apart portions, said first portion in heat conductive relationship to said heat conductive member within said chamber, said second portion in heat conductive relationship to said tip member; first and second heat responsive means having substantially similar characteristics of thermal deflection, said first and second Heat responsive means in heat conductive relationship to said first and second spaced apart portions, respectively, and each having a free end adapted for mutual engagement only when the temperature difference between said first and second spaced apart portions of said heater means exceeds a predetermined level, said temperature difference resulting from a difference in rates of heat transfer of said heat conductive member and said tip member; and means for sensing when said heat responsive means are engaged.

Claim 10

A sensing apparatus comprising a sensor device comprising: a housing member defining a chamber; a tip member adapted for being exposed to a fluid, said tip member secured to said housing and forming a closure for said chamber and to prevent fluid entrance into said chamber; a heat conductive member within said chamber having a greater heat transfer capability than said tip member; heater means within said chamber having first and second spaced apart portions, said first portion in heat conductive relationship to said heat conductive member within said chamber, said second portion in heat conductive relationship to said tip member; first and second heat responsive means having substantially similar characteristics of thermal deflection, said first and second Heat responsive means in heat conductive relationship to said first and second spaced apart portions, respectively, and each having a free end adapted for mutual engagement only when the temperature difference between said first and second spaced apart portions of said heater means exceeds a predetermined level, said temperature difference resulting from a difference in rates of heat transfer of said heat conductive member and said tip member; and means for sensing when said heat responsive means are engaged.

Claim 11

A sensing apparatus according to claim 10 wherein said means for sensing when said heat responsive means are engaged is an electrical circuit comprising a source of electrical potential operatively connected to said heat responsive means for opening and closing said circuit and a current indicating means adapted for indicating electrical current in said circuit when said heat responsive means are engaged.

Claim 12

A sensing apparatus according to claim 9 wherein the said sensor device said heat responsive means are bimetallic members.

Claim 13

A sensing apparatus according to claim 9 wherein in said sensor device, said heater means within said chamber is an electrical resistive element and is operatively connected to said source of electrical potential.

Claim 14

A sensing apparatus according to claim 11 wherein in said sensor device said heat conductive member is electrically conductive and is operatively connected to said electrical potential and to said electrical resistive element.

Claim 15

A sensing apparatus according to claim 12 wherein in said sensor device said tip member is electrically conductive and is operatively connected to said source of electrical potential and said electrical resistive element.

Claim 16

In combination, a container having walls adapted for containing a fluid therein, a sensor device at least partially positioned within a wall of said container, said device comprising: a housing member defining a chamber; a tip member adapted for being exposed to a fluid, said tip member secured to said housing and forming a closure for said chamber and to prevent fluid entrance into said chamber; a heat conductive member within said chamber having a greater heat transfer capability than said tip member; heater means within said chamber having first and second spaced apart portions, said first portion in heat conductive relationship to said heat conductive member within said chamber, said second portion in heat conductive relationship to said tip member; first and second heat responsive means having substantially similar characteristics of thermal deflection, said first and second heat responsive means in heat conductive relationship co said first and second spaced apart portions respectively, and each having a free end adapted for mutual engagement only when the temperature difference between said first and second spaced apart portions of said heater means exceeds a predetermined level, said temperature difference resulting from a difference in rates of heat transfer of said heat conductive member and said tip member; and means for sensing when said heat responsive means are engaged.

Claim 17

In combination, a container having walls adapted for containing a fluid therein, a sensor device at least partially positioned within a wall of said container, said device comprising: a housing member defining a chamber; a tip member adapted for being exposed to a fluid, said tip member secured to said housing and forming a closure for said chamber and to prevent fluid entrance into said chamber; a heat conductive member within said chamber having a greater heat transfer capability than said tip member; heater means within said chamber having first and second spaced apart portions, said first portion in heat conductive relationship to said heat conductive member within said chamber, said second portion in heat conductive relationship to said tip member; first and second heat responsive means having substantially similar characteristics of thermal deflection, said first and second heat responsive means in heat conductive relationship co said first and second spaced apart portions respectively, and each having a free end adapted for mutual engagement only when the temperature difference between said first and second spaced apart portions of said heater means exceeds a predetermined level, said temperature difference resulting from a difference in rates of heat transfer of said heat conductive member and said tip member; and means for sensing when said heat responsive means are engaged.

Claim 18

A combination according to claim 14 wherein said means for sensing when said heat responsive means are engaged is an electrical circuit comprising a source of electrical potential operatively connected to said heat responsive means for opening and closing said circuit and a current indicating means adapted for indicating electrical current in said circuit when said heat responsive means are engaged.

Claim 19

A combination according to claim 15 wherein in said sensor device said heat responsive means members are bimetallic members.

Claim 20

A combination according to claim 15 wherein in said sensor device said heater means within said chamber is an electrical resistive element and is operatively connected to said source of electrical potential.

Claim 21

A combination according to claim 17 wherein in said sensor device said heat conductivE member is electrically conductive and is operatively connected to said electrical potential and to said electrical resistive element.

Claim 22

A combination according to claim 18 wherein in said sensor device said tip member is electrically conductive and is operatively connected to said source of electrical potential and said electrical resistive element.