| 摘要 |
1329067 Moulding tetrahedral bodies ASCO SA 4 April 1972 [2 April 1971] 15416/72 Heading B5A A method of producing hollow tetrahedral bodies, comprises moulding two symmetrical triangular faces 4, and joining their bases 3 together with the distance between the apices 5 equal to the length of the bases 3. The bases can be joined by welding, adhesive or riveting. |
