| 摘要 |
A joint for three-dimensional grid structures composed of pyramidal and tetrahedral modules; the joint being composed of two solid semispherical caps (1, 3) with ovoidal seats (19), and of a central plate (2). By means of four perpendicular grooves (11) on one cap (1) and four perpendicular grooves (20) on the other (3), and by inserting a single central pin (9) screwed to an external nut (10), the caps (1, 3) and central plate (2) enclose the ends (4, 14) of rods (7, 18, 8) extending in all directions; which ends (4, 14) are screwed to the rods (7, 18, 8) by means of a respective welded conical fitting (6) and a respective lock nut (5). |
