| 摘要 |
PCT No. PCT/SE97/00823 Sec. 371 Date Nov. 20, 1998 Sec. 102(e) Date Nov. 20, 1998 PCT Filed May 21, 1997 PCT Pub. No. WO97/45215 PCT Pub. Date Dec. 4, 1997Method for the fabrication of cones of sheet material where the blank includes two curved edges that are circular and have the radius R and r respectively and a common center C. The blank further has two straight lateral edges which are angled in relation to the circular edges. An angle alpha between the radius, through a corner and a first straight edge is as great as an angle beta between the radius through a second straight edge. A frustum of a cone is obtained from the blank after rolling the cone such that the lateral edges have been united to make a joint that runs helically around the cone. |
