| 摘要 |
PURPOSE:To enable rubber packings each concentrically embedded therein with an iron core to be manufactured at a larege yield, by previosuly providing relatively hard premold rubber layers in a plurality of positions around the iron core so that the deflection of the iron core upon curing is limited to the minimum. CONSTITUTION:A premold layers 2 made of the same material as that of a main body and vulcanized up to about 70% of the normally vulcanized condition thereof, are formed on a ring-like iron core 1 in the positions at which the periphery of the iron core 1 is divided into 8 to 16 parts. Then, the surfaces of the premold layers 2 are roughened and cleaned by a solvent, and thereafter, a binder is applied to the exposed surface of the iron core 1 and the surfaces of the premold layers 2. Then a main rubber body 3 made of unvulcanized rubber which is previosuly extruded into a predetermined shape, is coated upon them, and the whole body is charged into a die mold which is maintained at the room temperature. Thereafter, the die mold is heated to the vulcanized temperature while pressure is applied to the whole of the die mold, thereby the main rubber body 1 and the premold layers 2 are vulcanized and molded in one unit. |
