US Patent 10271647 Work chair with adjustable tray

A work chair includes a chair body, a plurality of wheel sets mounted at the bottom side of the chair body, a seat cushion mounted at the top side of the peripheral wall of the chair body, two guide rails mounted at the chair body at one lateral side each defining a longitudinal sliding slot and locating notch in communication with the sliding slot, a tray, a pivot bolt pivotally connecting the tray to the sliding slots of the rail for allowing the tray to be moved along the sliding slots of the guide rails and having an engagement portion for selectively engaging in one locating notch of each guide rail to hold the tray positively at the selected elevational position for carrying tools.