A gripper includes grip members which are mounted on a first rotary shaft and a second rotary shaft, respectively, so as to be opened and closed. An engaging pawl is formed on an upper surface of the grip member. Both shafts are elevatable in an integral manner. A receptacle member is disposed below an exit star-wheel, and is arranged to rotate integrally with the star-wheel. The gripper is located below the flange of the vessel when receiving the vessel. Accordingly, the engaging pawl cannot contact the flange. When the vessel is depressed by the capping head during a capping operation, the engaging pawl engages the vessel. When the vessel is discharged, the vessel remains suspended above the receptacle member, and the gripper then descends to place the vessel on the receptacle member and to disengage the engaging pawl of the gripper. Accordingly, there is no scarring of the vessel when the vessel is introduced into and discharged from the screw capper, and a stable conveyance of vessels is enabled.
