| 摘要 |
PURPOSE:To improve working efficiency and to make possible mass production by constituting the titled device in such a manner that only the part requiring a heat treatment can be limited and be locally softened and that the heat treat ment temp. can be easily and exactly set and held. CONSTITUTION:A link chain 11 is arrayed to one strength length and is continuously conveyed by guide rails 22 and a link feed mechanism 25. After the scale sticking thereto is removed by wire brushes 26, respective links 5 are held by each piece in a horizontal state by means of link positioning levers 27of a heater 28. The held links 5 are grasped from above and below by electrodes 29 and thereafter electricity is conducted between both upper and lower electrodes 29 through the links 5 to harden the local part clamped between the electrodes 29 by the Joule heat. The heated part of the link 5 is cooled and tempered by the cooling water injected from nozzles 31. |
