Abstract: An adjustable chair includes a seat portion having a convex undersurface and a base portion having a concave upper surface. Low profile roller assemblies are fixed in a spaced apart relation along the convex undersurface. Tracks are affixed along the concave upper surface of the base portion. The roller assemblies are adapted for rolling contact with the tracks. A power transmission assembly has a first end which is pivotably coupled to the seat portion and has a second end which pivotably connects to the base portion. The power transmission assembly moves the seat portion along an arcuate path defined by the base portion. A noise dampening preload spring is associated with the second end of the power transmission assembly.

Abstract: A positionable chair-lounge has a base which has transverse support beams, a movable top section that has transverse beams and is supported upon rollers that engage arcuate tracks secured to the base, a gear head motor type of power assembly which directly drives a threaded shaft and a drive tube through an irreversible drive. One end of the power assembly is pivotally attached to the top section by a guiding bracket and the other end is pivotally attached to the base by a guiding bracket. The base and seat transverse beams and the power assembly are positioned so that the seat can be moved in an arcuate path relative to the base.