US Patent 7128563 Clamping device for injection-molding machine

A clamping device for injection molding machine is proposed. The clamping device has a movable mold holder, a guiding unit, a screw rod unit, a transmission unit, a first clamping unit, and a second clamping unit. Power from the driving source is transmitted via the transmission unit to the screw rod unit, so as to drive the movable mold holder to move in reciprocating motion. When the mold is actuated to close, the first clamping unit engages to a gear wheel member of the screw rod unit. The gear wheel member and the first clamping unit are driven by the second clamping unit to move for generating a rotational torque, and to drive the screw rod unit for generating a clamping thrust.