| 摘要 |
<p>A joint (52) for connecting arm portions (40, 42) of a ceiling or wall mounted support system includes housing members (60,62) with an annular bearing (64) interposed between opposed surfaces (82,84) thereof. The housing members are clamped together on an axle (98) such that a braking force generated between the bearing and the housing member surfaces opposes rotation of one arm portion relative to the other. A variable braking force is generated between the bearing and surfaces (206) of the housing members which are generally perpendicular to the opposed surfaces (82,84). The variable braking force is generated by a spring (182) and is greatest when the arm supporting a piece of equipment (24, 26, 28, 56) is at its lowest point, relative to the horizontal. This overcomes the increased forces in the spring which otherwise tend to cause the arm portion (42) to drift upward.</p> |
