Patent ID: 7063384

Claim:
A flexible chair back, comprising: a back supporting board made of plastic material provided with a hollow space and a flexible member integrally extending from an upper side of the hollow space and tilted slightly outwardly from a plane defined by the hollow space, the flexible member being provided with a hollow retaining post on an inner side thereof; a rear board; an upper end of the rear board being directly connected to an inner side of an upper end of the back supporting board by screwing a screw into a screwing retaining hole at an upper end of the back supporting board; the rear board having a retaining sleeve of substantially cylindrical shape; the retaining sleeve being extended toward the back supporting board from an inner surface of the rear board; and a spring sandwiched by the flexible member of the back supporting board and the rear board with one end housed in the retaining sleeve and another end mounted on the retaining post; whereby the flexible member of the back supporting board, being anchored on the spring, can provide a comfortable supporting mechanism for a seated person's back; wherein the retaining sleeve is provided with an opening having an inwardly inclined inner rim for preventing the spring getting stuck by the retaining sleeve caused by torsional bending of the flexible member. wherein the retaining sleeve is further provided with a lateral flange for retaining the spring more stably; and wherein the flexible member is an isolated object and has two opposite lateral axles in a top portion thereof that are pivotally connected to two corresponding axial holes on an inner rim of the hollow space of the back supporting board.