PURPOSE: To contrive to automatically mount a cork stopper to a container mouth part and seal the mouth part by holding and reversing the cork stopper body and a cork part, while the cork stopper body and cork part are respectively directed downward and upward, by fitting the cork part into the container mouth part being conveyed and provisionally driving the stopper, and by using a stopper-driving means equipped with a stopper-driving bar pressing the driven cork stopper body.

CONSTITUTION: A cork stopper-driving machine 1 engages and holds a rotary conveying device 8 for rotation-conveying a container 2 and a cork stopper 3 in a state where the stopper body 4 and cork part 5 of the cork stopper 3 are respectively directed downward and upward, and reverses the cork stopper. The driving machine is equipped with a cork stopper-holding mechanism 9 for fitting the cork part 5 into a container mouth part 2a being conveyed by the rotary conveying device 8 and driving the stopper provisionally and with a stopper-driving bar 10 for pressing the stopper body 4 of the provisionally driven cork stopper 3. Further, the driving machine is equipped with a stopper-driving means 11 mounted on the rotary conveying device 8 in the manner of moving together with the container 2. Thus, when the cork stopper 3 is conveyed into the cork stopper-driving machine 1, the cork stopper can be conveyed in the state, where the light cork part 5 is directed upward and the heavy upper side is directed downward, and can be driven efficiently.