Patent ID: 7690729

Claim:
An adjustable chair headrest frame comprising: a headrest provided with a pivotal frame at a rear side; a support frame pivotally combined with said pivotal frame of said headrest, said support frame formed with a recessed face having its outer periphery board with plural threaded holes; an adjusting device threadably assembled with said support frame, said adjusting device composed of a fit plate, at least one stop block, a holding plate, springs and a back plate, said fit plate having one side disposed with at least one passageway, at least one stop block received in opposite ends of a channel of said fit plate, said stop block having its outer circumferential side provided with projecting edges and its inner side fixed with a projecting member, each spring having its opposite ends respectively fitted on said projecting member of said at least one stop block, said spring received in said passageway of said fit plate, said holding plate formed with an accommodating chamber for receiving said fit plate and said stop blocks therein, said accommodating chamber having its lower side bored with at least one guide groove, said accommodating chamber having its inner opposite sides respectively disposed with continuously-arranged positioning notches, wherein when the projecting edges of the stop block are respectively aligned to said opposite positioning notches, a respective one of said springs will recover its elastic force to push said stop blocks to move outward and respectively be engaged with other positioning notches and fixed therein, said back plate positioned at rear side of said holding plate, said back plate bored with through holes respectively corresponding with said at least one guide groove of said holding plate, said back plate threadably assembled with said fit plate; and a combining plate threadably assembled with said fit plate of said adjusting device and connected at a rear side of a chair.