| 摘要 |
PURPOSE:To make operation simple and sure and facilitate use by providing an inside and an outside conductor contacts on the upper periphery of a welding torch and applying low voltage. CONSTITUTION:An inside cylindrical conductor contact 3 and an outside cylindrical elastic conductor contact 5 facing the former at a distance 4 are provided on the outer periphery of a torch 1. When the torch comes into contact, by malfunction, with a work or other foreign matter placed on a base material 2 through a jig, the foreign matter avts on the outside contact 5 and deforms by pressing inward. Contact is caused between the two contacts 3, 5 and current is led through it, and the change is detected by a detector 7. |
