ELECTRICAL HEATERS

• US 3,582,616 A
• Filed: 10/29/1968
• Issued: 06/01/1971
• Est. Priority Date: 10/29/1968
• Status: Expired due to Term

• Current Assignee: Ronald M. Wrob
• Original Assignee: Ronald M. Wrob
• Inventors: Wrob, Ronald M.
• Application Number:
  US04/771,468
• Time in Patent Office: 945 Days
• US Class Current: 219/541
• CPC Class Codes: H05B 3/48 heating conductor embedded in insulating material

Abstract

Electrical heaters having an outer metal sheath within which is a resistance element, conductors being in electrical contact with said element and projecting outwardly of said sheath for connection to a power source; said resistance element being surrounded by electrically insulating, heat-conductive material capable of withstanding relatively elevated temperatures, and hermetic seals provided at the ends of said sheath formed of swageable material capable of retention of inherent physical characteristics at substantially high temperatures.

Claims

1. A hermetic electrical device having a metal sheath;

an electrical element disposed within said sheath, said electrical element including a pair of terminals projecting outwardly endwise of said sheath;

electrically insulating, heat-conductive material surrounding said electrical element;

a hermetic hightemperature seal provided within said sheath surroundingly of said terminals, said seal being fabricated from gas-impervious swageable material capable of resisting deformation at temperatures in excess of 1,000* F., said material being selected from the class consisting of mica paper and boron nitride.

2. A hermetic electrical device as defined in claim 1 and further characterized by said seal comprising mica paper being of sheet character and wound upon itself to form a roll, a mica paper roll being positioned in tight, surrounding engagement with each terminal of said electrical element.

3. A hermetic electrical device as defined in claim 2 and further characterized by there being at least a pair of mica paper rolls in end to end relationship disposed closurewise within said sheath in tightly surrounding engagement with each terminal of said electrical element.

4. An electrical device as defined in claim 1 and further characterized by said seal material comprising mica paper formed into a disc.

5. An electrical device as defined in claim 4 and further characterized by a lava disc being presented on opposite sides of said mica paper disc.

6. An electrical device as defined in claim 5 and further characterized by at least one lava disc being presented on the outer face of said mica paper disc in abutting relationship.

7. An electrical device as defined in claim 1 and further characterized by said seal material comprising boron nitride in disc form.

8. An electrical device as defined in claim 7 and further characterized by a lava disc being presented on opposite sides of said boron nitride disc.

9. An electrical device as defined in claim 7 and further characterized by at least one lava disc being presented on the outer face of said boron nitride disc in abutting relationship.

10. A hermetic electrical device as defined in claim 1 and further characterized by said electrical element comprising an electrical resistance element electrical connected to said terminals said electrically insulating material comprising boron nitride.

11. An electrical device as defined in claim 10 and further characterized by said hermetic seal being constructed of mica paper would upon itself into roll form.

12. An electrical device as defined in claim 11 and further characterized by said resistance element being selected from the group consisting of molybdenum, tungsten, niobium, and graphite.

13. An electrical device as defined in claim 10 and further characterized by said hermetic seal consisting of mica paper formed into a disc, a lava disc being presented on the outer face of said mica paper disc in abutting relationship thereto.

14. An electrical device as defined in claim 13 and further characterized by said resistance element being selected from the group consisting of molybdenum, tungsten, niobium, and graphite.

15. An electrical device as defined in claim 10 and further characterized by said hermetic seal comprising a first lava disc disposed within said compartment, a boron nitride disc inserted in abutting relationship to said first lava disc and a second lava disc inserted within said compartment in abutting relationship to said boron nitride disc.

16. An electrical device as defined in claim 15 and further characterized by said resistance element being selected from the group consisting of molybdenum, tungsten, niobium, and graphite.

17. An electrical device as defined in claim 10 and further characterized by said resistance element being selected from the group consisting of molybdenum, tungsten, niobium, and graphite.

18. An electrical device as defined in claim 1 and further characterized by said insulating material comprising a core disposed within said sheath, said core having a pair of parallel longitudinal bores extending therethrough, said electrical element comprising a first conductor extending through one bore of said core and a second conductor extending through the other bore of said core, said conductors having inner and outer ends and being constructed of different metals, said conductors being joined at their inner end, said outer ends comprising said terminals.

19. An electrical device as defined in claim 18 and further characterized by said hermetic seal comprising mica paper formed into a disc, and at least one lava disc being presented on the outer face of said mica paper disc in abutting relationship.

20. An electrical device as defined in claim 18 and further characterized by said hermetic seal comprising boron nitride in disc form and at least one lava disc being presented on the outer face of said boron nitride disc in abutting relationship.

21. A hermetic electrical device having a metal sheath provided with an open end;

an electrical element disposed within said sheath and including a pair of terminals projecting outwardly endwise through said sheath open end;

electrically insulating, heat-conductive material surrounding said electrical element;

a metal plug provided within said sheath open end and having a pair of bores therein, said terminals extending through said bores, the diameter of each of said bores being greater than the diameter of said terminals, a hermetic high-temperature seal provided within each of said bores, said seal being fabricated from gas-impervious swageable material, capable of resisting deformation at temperatures in excess of 1,000* F., said material consisting of mica paper wound upon itself to form a rolled-formed sleeve for disposition within each plug bore surroundingly of the terminal of the resistance element.

22. A hermetic electrical device having a metal sheath provided with at least one open end;

an electrical element disposed within said sheath and including a pair of terminals projecting outwardly endwise through said sheath open end;

said electrical element consisting of an electrical resistance element being electrically connected to said terminals;

an electrically insulating heat-conductive material provided within said sheath surroundingly of said resistance element;

a metal plug provided within said sheath open end and having a pair of bores therein, said terminals extending through said bores, the diameter of each of said bores being greater than the diameter of said terminals;

a hermetic, high-temperature seal provided within each bore, said seal being fabricated from gas-impervious swageable material, capable of resisting deformation at temperatures in excess of 1, 000* F., said material consisting of mica paper wound upon itself to form a rolled form sleeve for disposition within each plug bore surroundingly of the adjacent terminal of the resistance element.

23. An electrical device as defined in claim 22 and further characterized By said resistance element being selected from the group consisting of molybdenum, tungsten, niobium, and graphite.

24. A hermetic electrical device having a metal sheath provided with at least one open end, a core of electrically insulating heat-conductive material disposed within said sheath, said core having a pair of parallel longitudinal bores extending therethrough, an electrical element including a pair of terminals, said electrical element comprising a first conductor extending through one bore of said core, a second conductor extending through the other bore of said core, said first and second conductors having inner and outer end portions and being constructed of different metals, said first and second conductors being joined at their inner end portions, the outer end portions of said first and second conductors projecting through said sheath open end and comprising said terminals, a metal plug provided within said sheath open end and having a pair of bores therein, said terminals extending through said bores, the diameter of each of said bores being greater than the diameter of said terminals, a hermetic, high-temperature seal provided within each bore, said seal being fabricated from gas-impervious swageable material, capable of resisting deformation at temperatures in excess of 1,000* F., said material consisting of mica paper wound upon itself to form a rolled-formed sleeve for disposition within each plug bore surroundingly of the terminal of said resistance element.