Heated respiratory hose wiring

A method of forming a heated hose comprising:

• extruding a continuous web of plastics material of substantially uniform width from a first extruder of a hose making apparatus;
• helically winding the extruded web about a mandrel or at least one rotating rod of the hose making apparatus to form a wall of the heated hose about a central axis of the heated hose;
• feeding a first heating wire and a second heating wire into a second extruder of the hose making apparatus;
• extruding a continuous bead of plastics material around the first heating wire and the second heating wire from the second extruder of the hose making apparatus such that the extruded bead emerges from the second extruder with the first heating wire at a first location within a cross-section of the extruded bead and the second heating wire at a third location within a cross-section of the extruded bead such that the first heating wire and the second heating wire are both fully surrounded by the plastics material of the extruded bead;
• helically winding the extruded bead onto and about an external surface of the wall of the hose formed from the helical winding of the extruded web to provide the wall a support helix that incorporates the first heating wire and the second heating wire;
• exerting tension on the first heating wire as the first heating wire is fed into the second extruder, and as the extruded bead is wound onto and about the external surface of the wall of the hose, to draw down the first heating wire toward the central axis of the hose such that the first heating wire migrates radially inward within the extruded bead from the first location already within the cross-section of the extruded bead to a second location within that is still the cross-section of the extruded bead, and that is closer to the wall of the hose and closer to the central axis than the first location within the cross-section of the first extruded bead;
• and
• exerting tension on the second heating wire as the second heating wire is fed into the second extruder and as the extruded bead is wound onto and about the external surface of the wall of the hose to draw down the second heating wire toward the central axis of the hose such that the second heating wire migrates radially inward within the extruded bead from the third location already within the cross-section of the extruded bead to a fourth location that is still within the cross-section of the extruded bead, and that is closer to the wall of the hose and closer to the central axis than the third location within the cross-section of the first extruded bead.