Patent ID: 8800447

Claim:
Sheet-fed or web-fed printing machine comprising: a main unit, at least one mobile inking carriage adapted to be coupled to the main unit for cooperation therewith during printing operations and to be moved away from the main unit during maintenance operations, said mobile inking carriage comprising at least one inking device, a control unit for controlling displacement of said mobile inking carriage toward and away from said main unit, and an access zone surrounding at least partly said mobile inking carriage for allowing a human operator to get access to said main unit and mobile inking carriage, which access zone lies outside of a displacement path of said mobile inking carriage, wherein said printing machine further comprises detection means for monitoring said access zone and detecting presence of a human operator within said access zone, wherein said optical detection means are located on a floor part of the printing machine so as optically scan a horizontal plane lying parallel above said access zone and close to the level of said access zone and detect trespassing of a human operator onto said access zone, wherein the floor part is made extending on each side of the main unit and the mobile inking carriage and is partially surrounded by barriers and side panels so as to force a human operator to pass through said access zone to get access to the main unit or to the mobile inking carriage, and wherein said control unit is operatively connected to said detection means so as to interrupt or prevent displacement of said mobile inking carriage upon detection of the presence of a human operator within said access zone before the human operator penetrates in the displacement path of the mobile inking carriage.