Electrically heated conduit

• US 5,791,377 A
• Filed: 07/08/1996
• Issued: 08/11/1998
• Est. Priority Date: 07/08/1996
• Status: Expired due to Fees

• Current Assignee: Yazaki Corporation
• Original Assignee: Yazaki Corporation
• Inventors: LaRochelle, Christopher John
• Primary Examiner(s): Scherbel, David
• Assistant Examiner(s): Hook, James F.
• Application Number:
  US08/679,373
• Time in Patent Office: 764 Days
• Field of Search: 138/33, 138/32, 138/104, 138/109, 138/127, 15/250.01, 15/250.03, 15/250.04, 15/250.05, 439/191, 439/192, 439/193, 439/194, 285/7, 285/149.1, 285/907
• US Class Current: 138/33
• CPC Class Codes: B60S 1/488 electrically
• CPC Class Codes: B60S 1/524 arranged in wiper blades
• CPC Class Codes: E03B 7/12 by preventing freezing
• CPC Class Codes: F16L 53/38 using elongate electric heating elements, e.g. wires or ribbons
• CPC Class Codes: H01R 13/005 Electrical coupling combined with fluidic coupling
• CPC Class Codes: H05B 3/58 Heating hoses; Heating collars

Abstract

A conduit is electrically heatable to prevent the freezing of a fluid flowing therethrough. The conduit comprises a tube having wires embedded in its walls and end fittings attached to either end of the tube which provide for fluid flow connection with the conduit and for electrical connection with the wires.

Claims

1. A conduit connectable to an electric circuit for heating by electric current supplied by the circuit, the conduit comprising:

a tube defining an interior fluid passage and having an outer surface, a first end and a second end;

first and second electrical conductors embedded within and extending between the first and second tube ends and exposed on the outer surface of the tube adjacent the first tube end;

a push-on end fitting for attachment to the first tube end and having a hollow stem for urging into the fluid passage of the tube, an electrically non-conductive shroud surrounding the stem and defining an annular receptacle around the stem for urging over the outer surface of the tube, and electrically conductive means disposed inside of the shroud for making electrical contact with exposed portions of the first and second conductors adjacent the first tube end.

2. A conduit according to claim 1 wherein the end fitting is molded in one piece from a plastic material and the conductive means is molded in place within the end fitting.

3. A conduit according to claim 1 wherein the electrically conductive means comprises shorting means for connecting the first and second conductors to one another.

4. A conduit according to claim 1 wherein the electrically conductive means comprises first and second terminals for contacting the first and second conductors respectively.

5. A conduit according to claim 4 wherein the first and second conductors are exposed at substantially diametrically opposite positions on the tube outer surface, and the first and second terminals each wrap around approximately half of the circumference of the receptacle.

6. A conduit according to claim 4 wherein the first and second electrical conductors are further exposed on the outer surface of the tube adjacent the second tube end, and further including:

a second push-on end fitting for attachment to the second tube end and having a hollow stem for urging into the fluid passage of the tube, an electrically non-conductive shroud surrounding the stem and defining an annular receptacle around the stem for urging over the outer surface of the tube, and electrically conductive shorting means disposed inside of the receptacle for connecting the first and second conductors to one another adjacent the second tube end when the shroud is urged over the second tube end.

7. A push-on end fitting for urging into connection with an end of a tube having an outer surface, a fluid passage, and first and second electrical conductors embedded within and extending along the length of the tube and exposed on the outer surface thereof adjacent the tube end, the end fitting comprising:

a hollow stem for urging into the fluid passage of the tube to provide a continuation of the fluid passage;

a shroud integral with the stem and defining an annular receptacle around the stem for urging over the outer surface of the tube; and

electrically conductive means positioned inside of the receptacle for making electrical contact with exposed portions of the first and second conductors adjacent the tube end.

8. A conduit according to claim 7 wherein the electrically conductive means comprises shorting means for connecting the first and second conductors to one another.

9. A conduit according to claim 7 wherein the electrically conductive means is molded in place within the end fitting.

10. An end fitting according to claim 7 wherein the electrically conductive means comprises first and second terminals for contacting the first and second conductors respectively.

11. A conduit according to claim 10 wherein the first and second terminals each wrap around approximately half of the circumference of the receptacle.

12. A conduit for carrying a fluid flow and connectable to an electric circuit, the conduit comprising:

a tube having an outer surface, an axial fluid passage, a first end and a second end;

first and second electrically conductive wires embedded in the tube and extending between the first and second tube ends, the wires exposed on the tube outer surface adjacent the second tube end and exposed at diametrically opposite positions on the tube outer surface adjacent the first tube end;

a first push-on end fitting for urging into attachment with the first tube end and having a hollow stem for insertion into the fluid passage of the tube and a shroud surrounding the stem and defining an annular receptacle around the stem for fitting around the outer surface of the tube;

first and second terminals having semi-circular wire contacting portions positioned inside of the receptacle, each of the wire contacting portions extending around approximately half of the inner circumference of the receptacle, and the terminals having connection tabs extending through the end fitting for connection to the electric circuit;

a second push-on end fitting for urging into attachment with the second tube end; and

shorting means disposed on the second end fitting for electrically connecting the first and second wires to one another adjacent the second tube end.