Abstract: A tray attached to a pivot housing, support arm, and armrest clamp may be easily and quickly detached and reattached to an armrest on a chair. The tray may rotate around an arm hub when a stationary lower index plate in the arm hub is displaced from an upper index plate in the index housing. The tray is restrained from rotation when the upper and lower index plates are in contact with one another. The tray may be disconnected from the support arm while the support arm remains clamped to an armrest. The armrest clamp includes a bevel gear driven in rotation by a clamping ring on the support arm. The bevel gear drives rack gear attached to a traveling clamp jaw. Rotating the clamping ring displaces the traveling clamp jaw relative to a stationary clamp jaw, enabling the armrest clamp to securely clamp to an armrest.

Abstract: A tray attached to a pivot housing, support arm, and armrest clamp may be easily and quickly detached and reattached to an armrest on a chair. The tray may rotate around an arm hub when a stationary lower index plate in the arm hub is displaced from an upper index plate in the index housing. The tray is restrained from rotation when the upper and lower index plates are in contact with one another. The tray may be disconnected from the support arm while the support arm remains clamped to an armrest. The armrest clamp includes a bevel gear driven in rotation by a clamping ring on the support arm. The bevel gear drives rack gear attached to a traveling clamp jaw. Rotating the clamping ring displaces the traveling clamp jaw relative to a stationary clamp jaw, enabling the armrest clamp to securely clamp to an armrest.