Method of attaching a cover to the spine of a book block formed of bound printed sheets

A method is provided for attaching a cover sheet by adhesive bonding to a spine of a book block formed of bound printed sheets, wherein after a binding process a plurality of such book blocks follow one another on a transport path at regular distances. The book blocks are arranged to be in a transverse position on the transport path. The cover sheets are clamped so that each cover sheet presents a spine portion and preformed cover side portions extending from the spine portion so that the cover side portions are freed of deformation after the spine portion of the cover sheet has been pressed to the spine of the book block. The book blocks are fed, respectively, an inner side of a clamped cover sheet oriented for adhesive bonding, facing the spine of the book block. The inner side of the cover sheet is pressed to the spine of the book block and to lateral flanks of the spine of the book block.