Abstract: A fill tube for filling a seam-welded tube with a ceramic powder as the seam-welded tube is being made by a tube making mechanism. The fill tube has a guide tube for directing the ceramic powder from a location upstream of a seam welder to a location downstream of the seam welder. A mounting bracket is attached to the upper end of the guide tube and has a powder channel directing the ceramic powder received from an external powder source into the guide tube and a wire channel directing wires received from an external source into the guide tube. A wire guide is disposed at the opposite end of the guide tube which locates the wires in the seam-welded tube as it is being filled with the ceramic powder.

Abstract: A coaxial thermoelement having a thermocouple wire coaxially disposed in a tubular metal sheath. A ceramic powder electrically is disposed in the tubular metal sheath to insulate the thermocouple wire from the tubular metal sheath. A thermocouple is formed by fusing the thermocouple wire to its metal sheath in each of two coaxial thermoelements and joining the fused ends of the two coaxial thermoelement to form a thermocouple junction.

Abstract: A tubular heating element (10) having a metal tube (12) filled with a ceramic material (14). The metal tube has a near zero or slightly positive temperature coefficient of resistance. In an alternative embodiment, a wire (16) is coaxially supported within the metal tube (12) by the ceramic material (14). This wire may be used to stiffen the tubular heating element (10) or may be used as an electrical conductor.

Abstract: A machine for continuously producing metal tubing from a flat metal strip in which the welder, weld closing rolls, and seam guide are attached to a base plate slidably attached to a support structure. The base plate is displaceable relative to the support structure between an operating position and a start position. The base plate may be displaced by a manually operated actuator or by an electromechanical mechanism. The base plate is placed in the start position when the machine is stopped and is slowly displaced to the operating position when the machine is restarted. During displacement of the base plate to the operation position, the welder overwelds a portion of the seam previously welded. The seam weld during a restart transition of the base plate from the start to the operating position produces a defect-free seam weld.

Abstract: A mechanism and method for counteracting and removing the twist of a rolled metal strip being formed into a tube by a tube forming machine. The mechanism has a frame rotatably mounted to the tube forming machine between the forming rolls and the seam guide. A pair of edge rolls are attached to the frame and are engageable with the opposing longitudinal edges of the rolled metal strip. Backing rolls, also attached to the frame, inhibit the transverse displacement of the rolled metal strip by the engagement of the edge rolls with the longitudinal edges of the metal strip. An adjustment screw rotates the frame relative to the tube forming machine about a longitudinal axis to align the longitudinal edges of the rolled metal strip with a seam guide prior to welding the longitudinal edges to each other.

Abstract: A thermoelectric device having constant voltage characteristics over an extended temperature range.