Apparatus for correcting the position of sheets
In an apparatus for correcting a position of a sheet which is transported in the grip of grippers on a feed drum of a sheet processing machine, in particular a sheetfed rotary printing press, provision is made for a gripper device of the drum to be mounted in independently rotatable arranged supports and for it to be possible for each support to be driven by a step-up gear mechanism.
1. An apparatus for correcting a position of a sheet transported in a sheet processing machine, the apparatus comprising:
a step-up gear mechanism;
a sensor for detecting a position of the sheet;
a drum having supports being rotatably mounted independently of one another and in each case being driven by said step-up gear mechanism; and
a gripper bar for fixing the sheet, said gripper bar being mounted in said supports, said gripper bar for correcting an oblique position as detected by said sensor, and said gripper bar transporting the sheet.
2. The apparatus according to claim 1 , further comprising sliding ball joints;
a coupling joint;
said drum has a base body; and
said gripper bar has a number of grippers disposed beside one another at intervals, and is mounted in said supports by means of said sliding ball joints, and is coupled to said base body of said drum by said coupling joint.
3. The apparatus according to claim 2 , further comprising drive shafts having ends, said base body is mounted on said ends of said drive shafts such that said base body can rotate about an axis of rotation of said drum.
4. The apparatus according to claim 2 , further comprising an actuating motor having a rod for laterally displacing said gripper bar and for acting on said base body of said drum by means of said rod.
5. The apparatus according to claim 1 , wherein said step-up gear mechanism has planet gear mechanisms.
6. The apparatus according to claim 5 ,
wherein said planet gear mechanisms each have an internal gear driven at a cycle rate of the sheet processing machine;
further comprising planet gears;
further comprising drive shafts for driving said planet gears; and
further comprising actuating motors each driving one of said drive shafts.
7. The apparatus according to claim 6 , wherein said actuating motors can be driven by a computer of a machine control system of the sheet processing machine following an intended value-actual value comparison of positioning data of the sheet to be transported.
8. A sheet fed rotary printing press, comprising:
an apparatus for correcting a position of a sheet in the sheetfed rotary printing press, said apparatus containing:
a step-up gear mechanism;
a sensor for detecting a position of the sheet;
a drum having supports being rotatably mounted independently of one another and in each case being driven by said step-up gear mechanism; and
a gripper bar for fixing the sheet, said gripper bar being mounted in said supports, said gripper bar for correcting an oblique position as detected by said sensor, and said gripper bar transporting the sheet.