Stack changing device

A process for automatically and continuously changing a sheet stack in a sheet feeder of a sheet-processing machine including a remaining-stack carrying device having remaining-stack bars, the sheet stack having a pair of opposing stack edges and a middle area interposed between the opposing stack edges, the stack changing process comprising the steps of:

• temporarily receiving a remaining stack from a pallet on the remaining-stack bars by sliding the remaining-stack bars underneath said remaining stack from a common side of the stack into a stack position with said remaining stack resting on a first set of the remaining-stack bars in a position above a second set of the remaining-stack bars,
• continuously raising said remaining stack with the remaining-stack bars and
• depositing said remaining stack on a newly fed-in sheet stack which has been moved into position below said remaining stack by sequentially removing the first set of remaining stack bars from the stack position starting with at least one of the remaining stack bars of the first set arranged in the middle area of the sheet stack and progressing outwardly to remaining stack bars of the first set adjacent side edges of the sheet stack such that the remaining stack is deposited on the second set of remaining stack bars, and then sequentially removing the second set of remaining stack bars starting with at least one of the remaining stack bars of the second set arranged in the middle area of the sheet stack and progressing outwardly to remaining stack bars adjacent side edges of the stack such that the remaining stack is thereupon joined with the newly fed-in sheet stack.

A device for changing a sheet stack in a sheet feeder of a sheet processing machine, the stack changing device comprising:

• a main stack lifting mechanism for raising and lowering of a sheet stack having opposing stack edges and a middle area,
• a remaining-stack carrying device including remaining-stack bars for temporarily receiving a remaining stack and transferring said remaining stack to a newly fed-in sheet stack, a drive mechanism for slidably moving said remaining stack bars underneath a remaining stack of sheets from a common side of the remaining stack,
• a remaining-stack lifting mechanism for raising the remaining-stack carrying device, and
• said drive mechanism being operable for sequentially removing the remaining stack bars from the remaining stack starting with at least one of the remaining stack bars in the middle area of the sheet stack and progressing outwardly to the remaining stack bars adjacent the opposed stack edges of the sheet stack.

A device for changing a sheet stack in a sheet feeder of a sheet-processing machine, the stack changing device comprising:

• a main stack lifting mechanism for raising and lowering of a sheet stack having a pair of opposing stack edges and a middle area interposed between the opposing stack edges,
• a remaining-stack carrying device including remaining-stack bars having different relative thicknesses for temporarily receiving a remaining stack and transferring said remaining stack to a newly fed-in sheet stack,
• a drive mechanism for slidably moving said remaining stack bars underneath a remaining stack of sheets from a common side of the remaining stack,
• a remaining-stack lifting mechanism for raising the remaining-stack carrying device, and
• said drive mechanism being operable for sequentially removing the relatively thicker remaining stack bars such that the remaining sheet stack is deposited on the relatively thinner remaining stack bars, and then sequentially removing the relatively thinner remaining stack bars such that the remaining stack is thereupon deposited on a newly fed-in sheet stack.

A device for changing a sheet stack in a sheet feeder of a sheet-processing machine, the stack changing device comprising:

• a main stack lifting mechanism for raising and lowering of a sheet stack having a pair of opposing stack edges and a middle area interposed between the opposing stack edges,
• a remaining-stack carrying device having remaining-stack bars including first remaining stack bars having a relatively high stack receiving surface and second remaining stack bars having a relatively low stack receiving surface,
• a drive mechanism for slidably moving said remaining stack bars underneath a remaining stack of sheets from a common side of the remaining stack,
• a remaining-stack lifting mechanism for raising the remaining-stack carrying device, and
• said drive mechanism being operable for sequentially removing the first remaining stack bars such that the remaining stack is deposited on the second remaining stack bars, and then sequentially removing the second remaining stack bars such that the remaining stack is thereupon deposited on a newly fed-in sheet stack.