Method and apparatus for opening folded, bound or stitched multi-sheet products, especially printed products

An apparatus for opening folded, bound or stitched, multi-sheet products, especially printed products, each having a folded edge and an opposite open side having a lap margin part, comprising:

• a pre-separation element for acting upon the lap margin part of the open side of the sheets of the product for displacing such lap margin part of the open side of the sheets in relation to remaining sheets of the products which are not engaged by the pre-separation element;
• means for moving the pre-separation element relative to the product towards the open side thereof and for engaging and moving an edge of the lap margin part of at least one of the open sides of the sheets relative to and towards the folded edge by said pre-separation element;
• said engaged lap margin part of the open side of the sheets being bowed out at the lap margin part where such sheets are engaged by the pre-separation element during continued relative movement between the pre-separation element and the product;
• a holder element introduceable into an opening between the bowed-out sheets and the remaining sheets of the product not engaged by the pre-separation element;
• and
• said sheets which are not engaged by the pre-separation element coming to bear upon said holder element.

An apparatus for processing folded, bound or stitched, multi-sheet products, each having a folded edge and an opposite open side having a lap margin part, comprising:

• a cell wheel rotatable about an axis of rotation;
• said cell wheel being provided with radially extending compartments for receiving the printed products and in which the printed products are movable in the direction of the axis of rotation of the cell wheel;
• each of said individual compartments being provided at least at an input portion thereof with a device for opening the printed products;
• each said opening device comprising:
• a pre-separation element acting upon the lap margin part of the open side of the sheets of the product for displacing such lap margin part of the open side of the sheets in relation to the remaining sheets of the product which are not engaged by said pre-separation element;
• means for moving the pre-separation element relative to the product towards the open side thereof and for engaging and moving an edge of the lap margin part of the open side of the sheets relative to and towards the folded edge by said pre-separation element;
• said engaged lap margin part of the open side of the sheets being domed-out at the lap margin part where such sheets are engaged by the pre-separation element during continued relative movement between the pre-separation element and the product;
• a holder element introduceable into an opening between the doomed-out sheets and the remaining sheets which are not engaged by the pre-separation element;
• and
• said sheets which are not engaged by the pre-separation element coming to bear upon said holder element.