Digital inkjet printing machine for printing on cylindrical substrates

A digital inkjet printing machine for printing on cylindrical substrates, comprising a conveyor table conveying at least one cylindrical substrate and at least one printing station equipped with a series of printheads having a parallel longitudinal axis, the series of printheads supported by a support structure, the support structure comprising a longitudinal plate, each print head of the series of printheads having a cradle housing supported by an angular support, wherein each angular support is supported by the longitudinal plate in a position that is linearly adjustable along the longitudinal plate itself, and in tum supports the cradle in an angularly adjustable position, and a toggle system having symmetrical connecting rods, each connecting rode having a lower end hinged to the longitudinal plate of the support structure and an upper end operatively connected to a screw nut engaged so as to travel along a screw having a vertical axis which intercepts the axis of the spindle, wherein said table has a vertical rotation axis and supports at least one spindle supporting said cylindrical substrate, wherein said spindle has an axis oriented radially relative to said vertical rotation axis, wherein said spindle is actuatable in rotation about its axis, wherein said conveyor table is configured to stop said spindle below said printheads, wherein said spindle stopped below said printheads has its axis parallel to the longitudinal axis of said printheads, wherein the axis of the spindle stopped below said printheads is coplanar with main planes in which said printheads lie, wherein said printheads are equidistant from the axis of said spindle, wherein there is provided a first adjustment setting adjusting the distance between the axis of the spindle and said printheads and at least a second adjustment setting adjusting the orientation of said main planes in which said printheads lie, said second adjustment setting configured to maintain the condition of the axis of the spindle stopped below said printheads being coplanar with the main planes in which said printheads lie as the distance between the axis of the spindle and said printheads varies.