| 摘要 |
A method and apparatus of forming curved hollow elements by drawing comprising providing a die having an inlet opening, providing a punch which is mounted for rotation at a center of rotation which is in the plane of the inlet opening with the punch having a shape of a section of an annulus with a center of the annulus corresponding to the center of rotation of the punch, placing a blank over the inlet opening of the die and driving the punch into the inlet opening to shape the blank into a curved hollow element. The blank is held over the die inlet opening by a blank holder and hydraulic or pneumatic jacks are connected to the die and/or punch for moving them with respect to each other to form the curved hollow elements. |
