| 摘要 |
The rim, made from metal from a blank that is extruded, shaped into circular shape and closed upon itself through jointing between the ends of the blank, comprises a pair of wings (27,28;127,128;227,228;327,328) connected by at least one bridge (23,26), and is characterised in that the axial distance between the wings at the jointing area (138,238,338) is greater than the axial distance between the wings at the areas far from the jointing area (138,238,338). |
