Patent ID: 7828507

Claim:
A stacking apparatus for forming stacks of flat objects, such as printed products, comprising a compartment which defines an upwardly open compartment space and which is bounded by a compartment base, opposite upstream and downstream sides when viewed in an ejection direction, and opposite lateral sides, at least one upstream guide element on the upstream side of the compartment space, and at least one downstream guide element on the downstream side of the compartment space, said upstream guide element and said downstream guide element being arranged adjacent one of said lateral sides of the compartment, and said compartment being mounted for rotation about a central axis, a drive mechanism for ejecting a stack of printed products from the compartment space in the ejection direction comprising a first drive connected to the upstream guide element and a second drive connected to the downstream guide element, wherein the first drive and the second drive are independently operable, wherein the drive mechanism is configured to selectively move the upstream guide element and the downstream guide element in the ejection direction to eject a stack formed in the compartment and move the upstream guide element and the downstream guide element toward each other to at least approximately bear against the stack being formed in the compartment in order to stabilize it during rotation of the compartment about the central axis, wherein said compartment is further bounded by a pair of lateral bounding elements which lie on said one lateral side of the compartment space so as to be directly engageable with the stack of flat objects formed in the compartment space, with the lateral bounding elements being positioned adjacent respective ones of the upstream guide element and downstream guide element and driven by the drive mechanism so as to be moved together with the upstream guide element and the downstream guide element, respectively, during said selective movement.