| 摘要 |
PURPOSE:To prevent cracks or wrinkling in an insulating sheet, by heating the insulating sheet and cutting off the opposite marginal parts of the lateral direction before winding the insulating sheet over-laid with a metallic sheet. CONSTITUTION:Untreated insulating sheet 1 is heated by a heating means 2 having a width larger than that of the insulating sheet 1. Then, the opposite ends of the insulating sheet 1 are cut off by cutters 3 and the insulating sheet 1 is rolled up round a former 4 to produce an insulating sheet 5. The rolled insulating sheet 5 is overlaid with a metallic sheet and they are wound together to produce a sheet-type transformer. Since the insulating sheet 5 is previously heated to cause strain therein and the opposite ends of the sheet in which the strain is caused are cut off before the insulating sheet 5 is wound together with the metallic sheet to produce a sheet winding, it is possible to prevent cracks or wrinkling in the insulating sheet after formation of the winding. |
