Jointed mounting, allowing adjustment around three independent axes

摘要

The mounting has a supporting arm (1) which can swing in a roughly horizontal plane around a support (3) with a roughly vertical axis (21). An object (9) is held by a carrier (8) which can rotate about an axis (28) on a second supporting arm (7), which is mounted on a roughly horizontal tilt axis (26) on the first arm, and which can move in a roughly vertical plane. The load (G) of the object is counteracted by the torque about the tilt axis of a spring (11) on the second arm, which is arranged between points (12,13) on the supporting arms. The sine of the angle (beta) between the spring action and the lever arm (17), which passes through the tilt axis and the attachment point on the second arm, is roughly equal to the sine of the angle (alpha) between the vertical load and the lever arm (18), which passes through the tilt axis and the centre of gravity of the object.