Patent ID: 7647746

Claim:
A capper head, comprising: a servo motor, a motor output shaft, said motor output shaft being rotated by said servo motor, a screw mechanism including a screw output shaft, said screw output shaft being rotated by said motor output shaft and being axially displaced by screw action based on rotation of said screw output shaft, a chuck linked to said screw output shaft, said chuck being capable of holding a cap that is tightened on a mouth section of a container, and a sliding engagement section that engages said screw output shaft with said motor output shaft so that the rotation can be transferred from said motor output shaft to said screw output shaft while allowing said axial displacement of said screw output shaft, wherein said screw mechanism further comprises a fixed nut that is thread-engaged with said screw output shaft and provides the screw action, and wherein said screw output shaft comprises a stroke difference absorption section that absorbs a stroke difference between said screw output shaft and said chuck based on a difference between pitches of said screw output shaft and said chuck.