Device and method for replacing the printing rollers of a printing unit, particulary for in-line flexograhpic rotary machines

A device for replacing the printing rollers of a printing unit, particularly for in-line flexographic rotary machines comprising:

• a working station for a first printing roller,
• a holding station for a second, held printing roller,
• a removal station for said first printing roller to be removed,
• movement means for the movement of said first printing from said work station to said removal station and for the movement of said second printing roller from said holding station to said work station,
• wherein:
• said movement means comprise a pair of rods that are pivoted with respect to a pivoting axis, each one of said rods comprising an abutment protrusion that is adapted to engage the lateral ends of said first printing roller and of said second printing roller,
• said holding station and said removal station are at a higher level than that of said work station,
• the rotation of said rods around said pivoting axis defining a region, said working station being arranged inside said region;
• said removal station and said holding station being arranged outside said region on mutually opposed sides thereof, said holding station, said working station, and said removal station being affected by the rotation of said rods within said region;
• thereby said pair of rods are adapted to move said first roller toward the removal station rotating around said pivoting axis, as consequence the second roller moving by gravity from the holding station to the working station.

A method for replacing printing rollers of a printing unit, particularly for in-line flexographic rotary machines comprising the steps of:

• having a first printing roller working in a work station;
• having a second printing roller held in a holding station;
• moving, by way of movement means, said first printing roller from said work station to a removal station and following, by way of said movement means, said second printing roller from said holding station to said work station,
• removing said first printing roller from said removal station;
• wherein said method comprising:
• said movement means rotating around a pivoting axis effecting the movement of said first roller toward the removal station and at the same time the second roller follows the rotation of said movement means moving by gravity from the holding station to the working station.