A CHAIR

摘要

PURPOSE: A chair comprising a back supporting board which is able to protrude is provided to return the tilted back supporting board to an initial position when a user returns to initial position and to work comfortably. CONSTITUTION: A chair comprises: a chair frame having a combining hole at the upper portion of central rod of a chair support(1); a seat plate frame which is fixed at the upper portion of the chair frame; and a back support frame(4) which is extended upwardly from back side of the chair frame. The upper end portion of the back support frame is fixed at the upper portion and back end of the seat plate frame is hinge-coupled at the lower portion of the back supporting board.