| 摘要 |
An adjustable hollow arm and joints therefor, one of the joints (7) being a universal joint, the other an angle joint. The universal joint comprises a hollow spherical member with generally opposite openings mounted in a holder to expose a face of the spherical member. One of said openings is in a quadrant of said face of the spherical member, and a hood covers the opening in the face, whereby the hood is asymmetrically offset from the centre of the exposed face. The mounting of the holder permits the hood to partake of movements over a full hemisphere relative to the holder. The angle joint permits passage therethrough with only one change of direction and comprises two portions each having an arcuate wall to move in overlapping motion with respect to each other, the arcuate walls being positioned on one side of the joint and a pair of planar walls opposite the arcuate walls. A hinge pin positioned on the centre line of the opposite walls and the centre of curvature of the arcuate walls joins the two portions whereby the angle joint pivots with a degree of movement up to 180 DEG . |
