Temperature sensors and methods of manufacture thereof

• US 20070258506A1
• Filed: 05/02/2006
• Published: 11/08/2007
• Est. Priority Date: 05/02/2006
• Status: Active Grant

• Current Assignee: Watlow Electric Manufacturing Company
• Original Assignee: Watlow Electric Manufacturing Company
• Inventors: Schwagerman, William, Frake, Robert
• Granted Patent: US 7,997,795 B2
• Time in Patent Office: Days
• US Class Current: 374/179
• CPC Class Codes: G01K 1/08 Protective devices, e.g. casings
• CPC Class Codes: G01K 1/14 Supports; Fastening devices; Arrangements for mounting thermometers in particular locations
• CPC Class Codes: G01K 1/146 arrangements for moving thermometers to or from a measuring position

Abstract

Temperature sensors and methods of manufacturing thereof, having an intermediate stop disposed along a set of wires, the intermediate stop is secured to the set of wires such that an insulator can be properly positioned around proximal end portions of the set of wires during assembly of the temperature sensor.

Claims

1. A temperature sensor comprising:

a first wire having a proximal end portion defining a proximal end, a distal end portion, an intermediate portion, and a covering;

a second wire having a proximal end portion defining a proximal end, a distal end portion defining a proximal end, an intermediate portion, and a covering;

a junction disposed at the proximal ends of the first and second wires;

an insulator surrounding a portion of the proximal end portions of the first and second wires;

a sleeving surrounding at least a portion of the intermediate portions of the first and second wires;

an insulating material surrounding the first and second wires between the insulator and the sleeving; and

a sheath disposed around the proximal ends of the first and second wires, the insulator, the insulating material, and at least a portion of the sleeving.

2. The temperature sensor of claim 1 wherein the sheath has a closed end and an open end, the junction being positioned proximate to the closed end, and the sleeving being positioned proximate to the open end.

3. The temperature sensor of claim 2 wherein the sheath includes a first outer dimension and a second outer dimension, the second outer dimension being greater than the first outer dimension, and the sheath proximate to the open end having the second outer dimension and the sheath around the insulator having the first outer dimension.

4. The temperature sensor of claim 3 wherein the sheath includes a tip tapered from the first outer dimension to a third outer dimension proximate to an end of the sheath proximate to the proximal ends of the first and second wires, the third dimension being smaller than the first outer dimension and the second outer dimension.

5. The temperature sensor of claim 3 wherein the sheath includes a transition portion of multiple outer dimensions between the first outer dimension and the second outer dimension.

6. The temperature sensor of claim 2 wherein the sleeving is positioned proximate to the open end of the sheath and at least partially extends from the open end.

7. The temperature sensor of claim 1 wherein the sheath includes a reduced portion securing the sleeving and the first and second wires within the sheath.

8. The temperature sensor of claim 1 wherein the covering of the first wire and the second wire include polyimide.

9. The temperature sensor of claim 1 wherein the sleeving is flexible.

10. The temperature sensor of claim 1 wherein the sleeving includes a fiberglass.

11. The temperature sensor of claim 1 wherein the sleeving includes a braided insulating material.

12. The temperature sensor of claim 1 wherein the insulator includes an insulating material selected from the group consisting of magnesium oxide, silicon oxide, and aluminum oxide.

13. The temperature sensor of claim 1 wherein the insulator includes a compressed powder insulating material.

14. The temperature sensor of claim 1 wherein the portions of the first and second wires surrounded by the insulator exclude the coverings.

15. The temperature sensor of claim 1 wherein the insulating material includes a polyimide tape wrapped around the first and second wires.

16. The temperature sensor of claim 1 wherein the insulating material is a first insulating material, further comprising a second insulating material surrounding the first and second wires, the first insulating material being positioned proximate to the insulator and the second insulating material being positioned proximate to the sleeving, the second insulating material being spaced apart from the first insulating material thereby forming a gap therebetween.

17. A temperature sensor comprising an intermediate stop disposed along a set of wires, the intermediate stop being secured to the set of wires such that an insulator can be properly positioned around proximal end portions of the set of wires during assembly of the temperature sensor.

18. The temperature sensor of claim 17 wherein the intermediate stop is a polyimide tape.

19. The temperature sensor of claim 17 wherein the insulator is a compactable perform.

20. The temperature sensor of claim 19 wherein the insulator includes magnesium oxide.

21. The temperature sensor of claim 17, further comprising a sleeving surrounding the distal end of the set of wires and adjacent the intermediate stop.

22. The temperature sensor of claim 21 wherein the intermediate stop includes braided fiberglass.

23. The temperature sensor of claim 21, further comprising a temperature sensing element selected from the group consisting of a thermocouple, a resistance temperature detector (RTD), and a thermistor.

24. A temperature sensor assembly having a thermocouple formed by an end of a first wire and an end of a second wire, the assembly comprising:

means for insulating non-insulated portions of the first and second wires proximate to the thermocouple;

means for insulating first insulated portions of the first and second wires adjacent to the means for insulating the non-insulated portions;

means for insulating second insulated portions of the first and second wires adjacent to the means for insulating the first insulated portions; and

a sheath having a closed end and an open end, the sheath surrounding the means for insulating non-insulated portion, means for insulating the first insulated portions, and at least a portion of the means for insulating the second insulated portions, the sheath including means for securing the means for insulating the second insulated portions within the sheath and means for securing the means for insulating non-insulated portions within the sheath.

25. A method of manufacturing a temperature sensor having a first wire and a second wire, the method comprising:

stripping a portion of a covering from a proximal end portion of the first and second wires to define insulated distal end portions and stripped proximal end portions;

sliding a sleeving over at least a portion of the insulated distal end portions of the first and second wires;

applying an insulating material around at least a portion of the insulated distal end portions of the first and second wires;

sliding an insulator over the stripped proximal end portions of the first and second wires and against the insulating material;

forming a junction at ends of the stripped proximal end portions of the first and second wires;

sliding a sheath over the insulator, the insulating material, and at least a portion of the sleeving; and

reducing an outer dimension of at least a portion of the sheath.

26. The method of claim 25 wherein applying includes applying the insulating material around at least a portion of the sleeving.

27. The method of claim 25 wherein the sliding includes positioning the sheath so that a portion of the stripped portions of the first and second wires extend from an open proximal end of the sheath, and further comprising closing an open end of the sheath following forming the junction.

28. The method of claim 25, further comprising reducing a portion of the sheath surrounding the sleeving.

29. The method of claim 25 wherein forming the junction is selected from the group consisting of welding, soldering, and bonding.

30. The method of claim 25, further comprising tapering an end portion of the sheath proximate to the formed temperature sensor.

31. The method of claim 25, further comprising sanding an end portion of the sheath proximate to the formed junction.

32. The method of claim 25, further comprising applying an insulating material as the covering to the first and second wires prior to stripping the portion of the first and second wires of the covering.

33. The method of claim 25 wherein reducing the outer dimension of the sheath includes reducing the outer dimension along a substantially full length of the sheath.

34. The method of claim 25, further comprising bending a portion of the sheath.

35. The method of claim 25 wherein sliding the sheath over at least a portion of the sleeving includes leaving a portion of the sleeving from being covered by the sheath.

36. The method of claim 25 wherein applying an insulating material around at least a portion of the insulated distal end portions of the first and second wires includes applying a first insulating material around a portion of the sleeving and a portion of the first and second wires and applying a second insulating material around the first and second wires and spaced apart from the first insulating material to form a gap therebetween, wherein the insulator is against a portion of the second insulating material.