Printing plate pressure adjustment system and can decorator employing same

A printing plate pressure adjustment system for a can decorator including a printing plate cylinder assembly having a printing plate cylinder, a printing plate cylinder drive shaft, and an eccentric bushing disposed around the printing plate cylinder drive shaft, and a blanket wheel, wherein rotation of the eccentric bushing causes the printing plate cylinder to move toward or away from the blanket wheel, said system comprising:

• an actuator;
• a drive mechanism coupled between the actuator and the eccentric bushing, the drive mechanism including:
• an elongated member coupled to the eccentric bushing, wherein operation of the actuator causes the elongated member to move to rotate the eccentric bushing;
• and
• a worm gear structured to rotate in response to operation of the actuator,
• wherein rotation of the worm gear causes the elongated member to move,
• wherein the actuator is an air motor;
• and wherein the drive mechanism further comprises:
• an eccentric pivot operatively structured to rotate in response to operation of the actuator, wherein the elongated member is coupled between the eccentric pivot and the eccentric bushing, and wherein rotation of the eccentric pivot causes the elongated member to move.

A can decorator comprising:

• a blanket wheel;
• a printing plate cylinder assembly having a printing plate cylinder, a printing plate cylinder drive shaft, and an eccentric bushing disposed around the printing plate cylinder drive shaft, wherein rotation of the eccentric bushing causes the printing plate cylinder to move toward or away from the blanket wheel;
• and
• a printing plate pressure adjustment assembly including:
• an actuator;
• a control system structured to control operation of the actuator to adjust a pressure between the printing plate cylinder assembly and the blanket wheel;
• and
• a drive mechanism coupled between the actuator and the eccentric bushing, the drive mechanism including an elongated member coupled to the eccentric bushing, wherein operation of the actuator causes the elongated member to move to rotate the eccentric bushing,
• wherein the control system is structured to adjust the pressure between the printing plate cylinder and the blanket wheel to a desired pressure,
• wherein the control system is structured to control the actuator such that the printing plate cylinder moves away from the blanket wheel in a large step greater than 0.001 inch and to subsequently control the actuator such that the printing plate cylinder moves toward the blanket wheel in fine incremental steps of less than 0.001 inch until the desired pressure between the printing plate cylinder assembly and the blanket wheel is reached.