| 摘要 |
PURPOSE:To prevent breaking of a heater even if a product falls down several times, to keep the quality of the product, and to improve safety, by a method wherein devices for preventing breaking of a heater, formed by a conical spring, are located to the top and the bottom end of a vertical type quartz-sheathed element heater. CONSTITUTION:A large size part 5a of a head part 5 of an end cap 4 is inserted in the small size side 7 of a conical coil spring 6 for locking. Meanwhile, a large size side 8 of the conical coil spring 6 is secured to a mounting metal 9 fastened to a body case 1. In this construction, if a product falls down, an impact force is absorbed through expansion and contraction in vertical and lateral direction of the conical coil spring 6, and prevents propagation thereof to a vertical type quarts-sheathed element heater unit 2. Especially, in the part, where the coil spring 6 is locked to the head part 5, the end parts of the coil spring and the head part are located together on their respective small size sides, whereby the further away they are spaced from a locking point P, the wider a gap 12 provided between the two parts becomes, and this enables effective absorption of variation such as lateral vibration. |
