| 摘要 |
A connective joint (10) comprises the following seven elements: (a) four quarter spheres (20, 22, 24 and 26) arranged in adjacent quadrant relationship to form a substantially spherical element or "ball". The quarter spheres are provided with grooved edges that form two substantially perpendicular grooves extending around the spherical element (20, 22, 24 and 26); (b) two hinge elements (28, 30), each having a ring shaped portion that is inserted in an individual one of the two grooves; (c) a device for applying a force between two diametrically opposing ones of the quarter spheres (20, 22, 24 and 26) in the spherical element. |
