Patent ID: 8726805

Claim:
A sheet-fed or web-fed letterpress printing machine comprising an impression cylinder, at least one inking device with an inking train comprising inking rollers, and at least one letterpress forme cylinder comprising raised printing portions that are inked by contact with specific inking rollers of the said at least one inking device that are placed in direct contact with said letterpress forme cylinder, wherein said letterpress forme cylinder is driven by first drive means, wherein said inking device is driven by second drive means, said second drive means being mechanically independent from said first drive means, and wherein a control unit is coupled to said second drive means for adjusting a circumferential speed of said specific inking rollers with respect to a circumferential speed of said letterpress forme cylinder and thereby adjust deposition of ink by said inking device on said letterpress forme cylinder, said control unit being designed to adjust the circumferential speed of said specific inking rollers with respect to the circumferential speed of said letterpress forme cylinder to counteract or exacerbate accumulation of ink on edges of the raised printing portions of said letterpress forme cylinder, the circumferential speed of the inking rollers that are placed in direct contact with said letterpress forme cylinder being adjusted by the control unit so as to be higher or lower than that of the letterpress forme cylinder.