An over-varnish unit and mandrel pre-spin system for a can decorator, especially for beverage can bodies, can have a mandrel pre-spin belt that is outside of the over-varnish unit housing. The position of the can infeed on the mandrel wheel and the print point is controlled.

An over-varnish unit and mandrel pre-spin system for a can decorator, especially for beverage can bodies, can have a mandrel pre-spin belt that is outside of the over-varnish unit housing. The position of the can infeed on the mandrel wheel and the print point is controlled.

A print registration system for a beverage can decorator includes an axial registration system and a circumferential registration system. Each registration system is independent and includes a slider that is translated by a motorized lead screw. Axial movement of the axial registration slider is transmitted to axial adjustment of the plate cylinder by a mechanical connection between the axial registration slider and the plate cylinder shaft. Translation of the circumferential registration slider is transmitted to a helical gear mounted to the plate cylinder shaft such that the plate cylinder shaft is rotated by the movement of the circumferential registration slider upon engagement of the helical driven gear with a stationary drive gear.

Plate cylinder driving devices of a printing machine are provided with a drive shaft driving the plate cylinder, a drive helical gear fixed to the drive shaft, and an anti-backlash helical gear rotatably connected to the drive shaft and is biased by at least a spring towards a direction for preventing backlash. Both the drive helical gear and the anti-backlash helical gear are engaged with the main gear, and a plate provided with plural holes accommodating rollers is provided between the drive helical gear and the anti-backlash helical gear. Friction between the anti-backlash gear and the drive gear is reduced by a simple mechanism in the plate cylinder driving devices in a printing machine.

A print registration system for a beverage can decorator includes an axial registration system and a circumferential registration system. Each registration system is independent and includes a slider that is translated by a motorized lead screw. Axial movement of the axial registration slider is transmitted to axial adjustment of the plate cylinder by a mechanical connection between the axial registration slider and the plate cylinder shaft. Translation of the circumferential registration slider is transmitted to a helical gear mounted to the plate cylinder shaft such that the plate cylinder shaft is rotated by the movement of the circumferential registration slider upon engagement of the helical driven gear with a stationary drive gear.

An oscillating roller system for a beverage can decorator is driven back and forth by a cam follower. A cam body having a cam is mounted to a frame of the inker system. Three oscillating cam roller assemblies are positioned about the cam body. Rotation of the cam oscillates the cam followers for each one of the oscillating rollers. Bearings of the oscillating roller assemblies includes an inlet gallery and outlet gallery for a closed loop lubrication system. The rollers are water cooled.

An over-varnish unit and mandrel pre-spin system for a can decorator, especially for beverage can bodies, can have a mandrel pre-spin belt that is outside of the over-varnish unit housing. The position of the can infeed on the mandrel wheel and the print point is controlled.

An over-varnish unit and mandrel pre-spin system for a can decorator, especially for beverage can bodies, can have a mandrel pre-spin belt that is outside of the over-varnish unit housing. The position of the can infeed on the mandrel wheel and the print point is controlled.

An oscillating roller system for a beverage can decorator is driven back and forth by a cam follower. A cam body having a cam is mounted to a frame of the inker system. Three oscillating cam roller assemblies are positioned about the cam body. Rotation of the cam oscillates the cam followers for each one of the oscillating rollers. Bearings of the oscillating roller assemblies includes an inlet gallery and outlet gallery for a closed loop lubrication system. The rollers are water cooled.

Plate cylinder driving devices of a printing machine are provided with a drive shaft driving the plate cylinder, a drive helical gear fixed to the drive shaft, and an anti-backlash helical gear rotatably connected to the drive shaft and is biased by at least a spring towards a direction for preventing backlash. Both the drive helical gear and the anti-backlash helical gear are engaged with the main gear, and a plate provided with plural holes accommodating rollers is provided between the drive helical gear and the anti-backlash helical gear. Friction between the anti-backlash gear and the drive gear is reduced by a simple mechanism in the plate cylinder driving devices in a printing machine.