| 摘要 |
PURPOSE:To prevent a heating wire from slackening by a structure wherein a belt-like heating wire is alternately lain between a pair of groups of pins and given tension by means of elastic material. CONSTITUTION:A working tension is applied to the directions aparting from each other or to the direction toward the inner wall face of the upper wall 11 of a frame 10 and the direction toward the inner wall face of the lower wall 11 of the frame 10 to a pair of the groups 18 of the pins 17, between each of which the heating wire 20 is lain, by means of the elastic material 19 serving as a tension mechanism. Accordingly, the heating wire, which is lain between a pair of the groups 18 of the pins, is also put under tension. As a result, even when the heating wire 20 elongates itself due to the generation of heat, the groups 18 of the pins are displaced by the tension mechanism, resulting in keeping the heating wire 20 under tension at all times and enabling to prevent the heating wire 20 from slackening with a simple configuration. |
