Apparatus for impression throw-on and throw-off and, for changing cylinders, and for causing a long stroke to be executed by an impression cylinder of a rotary gravure press

Claim 1

Apparatus for impression throw-on and throw-off and, as is necessary for changing cylinders, for causing a long stroke to be executed by an impression cylinder acting on the plate cylinder of a rotary gravure press, wherein the two journal bearings are each connected to a piston rod of the double acting piston-cylinder units serving to raise and lower the impression cylinder, characterised in that the piston rods (6) extending out of the cylinders (12) are rotatably but axially undisplaceably mounted in the journal bearings (7) and that, on the sides opposite to the piston rods (6) spindles (23) which are screwed into the pistons (19) having screwthreads (21) are provided with unthreaded portions on which worm wheels (36) which are fixed with respect to the housing and in mesh with drivable worms (4) are secured against rotation but to allow limited axial displacement through a distance corresponding to the stroke between impression throw-on and throw-off.