An assembly for supporting a device for movement between several positions, the assembly comprising a first four-bar subassembly including proximate and distal ends and a second four-bar subassembly including proximate and distal ends and first and second link members that pivot about substantially parallel axis, the distal end of the first four-bar subassembly linked to the proximate end of the second four-bar subassembly for rotation about an additional axis that is substantially perpendicular to the parallel axis.