Abstract: An adjustable chair includes upper and lower base members, a seat assembly secured to the upper base member, and a chair adjusting mechanism. In an embodiment the upper base member is connected to the lower base member by first and second linking members each having a first end connected to the lower base member and a second end slideably received in corresponding first and second arcuate tracks disposed in the upper base member, such that movement of the second ends into and out of the tracks results in vertical movement of the seat assembly relative to the base. In a further embodiment the seat bottom and seat base comprise cooperating arcuate rails, tracks, and/or bearing members, where cooperative action of the arcuate rails, tracks, and/or bearing members enables the seat bottom to tilt relative to the seat base.

Abstract: An adjustable chair includes upper and lower base members, a seat assembly secured to the upper base member, and a chair adjusting mechanism. In an embodiment the upper base member is connected to the lower base member by first and second linking members each having a first end connected to the lower base member and a second end slideably received in corresponding first and second arcuate tracks disposed in the upper base member, such that movement of the second ends into and out of the tracks results in vertical movement of the seat assembly relative to the base. In a further embodiment the seat bottom and seat base comprise cooperating arcuate rails, tracks, and/or bearing members, where cooperative action of the arcuate rails, tracks, and/or bearing members enables the seat bottom to tilt relative to the seat base.