Rod fixing device with ball head joints

摘要

The device (1) comprises a tube in which are located three threaded rods (5-7) mounted parallel to each other. Each threaded rod has at its end a ball joint (8-10). The rods are mounted in such a way that they can be adjusted longitudinally within the tube. The locus of the centre points of their heads describes an equilateral triangle (20). A support cover plate (19) is positioned on top of the ball head joints. The joints move within slots on the cover plate allowing it to tilt. When the threaded rods are adjusted in length the plane of the cover plate always lies parallel to the plane of the centre points of the ball heads.