| 摘要 |
PURPOSE:To prevent the deflection of the sheathed heater and the deformation of a metal pipe at the annealing by adding a slide mechanism which moves according to the thermal expansion of the metal pipe to the clamp device which holds the metal pipe. CONSTITUTION:The metal pipe 2 of the sheathed heater is held by the clamp devices 3, 3' which are connected to the both ends of the secondary coil of a transformer 1. A support part 5 is provided to at least one of the clamp devices 3, 3' and is held slidably in the groove 6 formed in a base board 4. When voltage is applied between the clamp devices 3, 3' and current flows in the metal pipe 2, the annealing of the metal pipe 2 is accomplished by Joule heat. At this time, the thermal expansion of the metal pipe 2 is absorbed by the movement of one clamp device 3, whereby the deformation of the metal pipe 2 is prevented. |
