| 摘要 |
<p>The present invention relates to a motor-less automatic retraction device that can insert a vision tube capable of monitoring the inside of a furnace to mange the internal state of the furnace and control the temperature of the furnace into the furnace and retract the vision tube from the furnace in a motor-less manner. A conventional retraction device is disadvantageous in that is is expensive, voluminous, difficult to install, thus requiring expert's help to install, and difficult to repair at the time of breakdown, and requires expensive repairing costs. In order to overcome the above-described disadvantages, and object of the present invention is to develop a motor-less automatic retraction device that can insert the vision tube into the furnace and retract the vision tube from the furnace using a spring, so the device is easily to install due to its small size and lightweight, is easy to repair, and allows repairing costs to be reduced.</p> |
