Thermocouple structure and method of manufacturing same

Claim 2

A thermocouple structure comprising a pair of thermocouple wires, the wires being joined together at one end to form a thermocouple, a metallic sheath closed at one end surrounding said wires and enclosing at said one end the thermocouple of said wires, the other ends of said wires being positioned outside the open other end of said sheath, the diameter of said sheath and the separation of said sheath from said wires being smaller at said one end than at said other end, crushed compacted mineral oxide contained within said metallic sheath, said mineral oxide serving to insulate said wires from said sheath and serving to insulate one of said thermocouple wires from the other, and ceramic cement provided at the other end of said sheath from which the thermocouple wires extend, said ceramic cement serving to seal said wires within said sheath and to contain the crushed compacted mineral oxide therein.

Claim 3

An EMF or voltage sensing device comprising the thermocouple structure of claim 1 and means electrically connected with said other ends of said wires for detecting a voltage difference between said other ends of said wires.

Claim 4

A thermocouple structure in accordance with claim 1 wherein said mineral oxide is magnesium oxide.

Claim 5

A thermocouple structure in accordance with claim 1 wherein one of said pair of thermocouple wires is made of a nickel chromium alloy comprising about 90% nickel and 10% chromium as the positive wires of said pair of thermocouple wires, the other of said thermocouple wires being made up of a nickel alloy containing about 94% by weight nickel and small amounts of aluminum, manganese and silicon.

Claim 6

A thermocouple structure in accordance with claim 4 wherein said nickel chromium alloy is Chromel and wherein said nickel alloy is Alumel.

Claim 7

A thermocouple structure in accordance with claim 1 wherein said thermocouple formed by joining said wires together at said one end is integral with said sheath at said one end thereof.

Claim 8

An EMF or voltage sensing device comprising the thermocouple structure of claim 6 and means electrically connected with said other ends of said wires for detecting a voltage difference between said other ends of said wires.

Claim 9

A thermocouple structure in accordance with claim 6 wherein said mineral oxide is magnesium oxide.

Claim 10

An EMF or voltage sensing device in accordance with claim 7 wherein said mineral oxide is magnesium oxide.

Claim 11

A thermocouple structure in accordance with claim 1 wherein said metallic sheath is made up of a stainless steel.

Claim 12

A thermocouple structure in accordance with claim 1 wherein said thermocouple wires are made up of constantan, a nickel copper alloy comprising about 40-45% by weight nickel and about 55-60% by weight copper.

Claim 13

A thermocouple structure in accordance with claim 1 wherein said metallic sheath is made of Inconel, a corrosion resistant alloy of nickel and chromium.

Claim 14

A thermocouple structure in accordance with claim 1 wherein said thermocouple is insulated from said sheath.

Claim 15

A thermocouple structure comprising a pair of thermocouple wires, the wires being stripped of insulation material thereon and joined at one end to form a thermocouple, a metallic sheath closed at one end surrounding said wires and enclosing at said one end the thermocouple of said wires, the other ends of said wires being positioned outside the open other end of said sheath, the diameter of said sheath and the separation of said sheath from said wires being smaller at said one end than at said other end, crushed compacted mineral oxide contained within said metallic sheath, said mineral oxide serving to insulate the stripped portions of said wires from said sheath and serving to insulate the stripped portions of said thermocouple wires from each other, and ceramic cement provided at the other end of said sheath from which the thermocouple wires extend, said ceramic cement serving to seal said wires within said sheath and to contain the crushed compacted mineral oxide therein, portions of the thermocouple wires within said sheath and sealed therein by contact with said additional ceramic cement being provided with insulating material thereon.

Claim 16

A thermocouple structure comprising a pair of thermocouple wires, the wires being stripped of insulation material thereon and joined at one end to form a thermocouple, a metallic sheath closed at one end surrounding said wires and enclosing at said one end the thermocouple of said wires, the other ends of said wires being positioned outside the open other end of said sheath, the diameter of said sheath and the separation of said sheath from said wires being smaller at said one end than at said other end, crushed compacted mineral oxide contained within said metallic sheath, said mineral oxide serving to insulate the stripped portions of said wires from said sheath and serving to insulate the stripped portions of said thermocouple wires from each other, and ceramic cement provided at the other end of said sheath from which the thermocouple wires extend, said ceramic cement serving to seal said wires within said sheath and to contain the crushed compacted mineral oxide therein, portions of the thermocouple wires within said sheath and sealed therein by contact with said additional ceramic cement being provided with insulating material thereon.

Claim 17

An EMF or voltage sensing device comprising the thermocouple structure of claim 14 and means electrically connected with said other ends of said wires for detecting a voltage difference between said other ends of said wires.

Claim 18

A thermocouple structure in accordance with claim 14 wherein the wires within said sheath at said one end thereof have a diameter smaller than the diameter of the wires extending outside the other end of said sheath.

Claim 19

A thermocouple structure in accordance with claim 1 wherein said thermocouple formed by joining said wires together at said one end is integral with said sheath at said one end thereof.

Claim 20

A thermocouple structure in accordance with claim 1 wherein said mineral oxide is selected from the group consisting of magnesium oxide, zirconium oxide, thorium oxide, beryllium oxide and aluminum oxide.

Claim 21

A thermocouple structure in accordance with claim 1 wherein said thermocouple is insulated from said sheath.