摘要 |
A seat back adjustment unit including a seat attaching plate which is fixedly secured to the seat of a chair and a back mounting plate which will have mounted thereon the customary seat back. The seat attaching plate has an upwardly and rearwardly curved portion on which there is mounted an adjustment unit. The adjustment unit in turn carries a lower generally horizontal portion of the back mounting plate. The adjustment unit includes a housing which is guidedly mounted on the curved rear portion of the seat attaching plate while the same housing has guidedly received therein the lower portion of the back mounting plate. The adjustment unit includes within the housing thereof a reduction gear drive unit which includes two driven member interlocked by pin and slot connections to the seat attaching plate and the back mounting plate for selective relative movement between the plates and the housing of the adjustment unit. A single actuator is selectively positionable to drive a selective half of the reduction gear drive unit to adjust either the tilt or the position of the seat back. |