| 摘要 |
<p>A device for the mechanical pressing of rounded book blocks held clamped in the region near the back is presented. The device includes a molding tool, which acts upon the book block back with a pressing force. A carriage is provided which receives the molding tool and is pivotable onto alternate sides of the book block back via a drive disposed on curved tracks in oppositely arranged, vertically displaceable bearings. The traveled radius of the active surface of the molding tool is smaller than the radius of the book block back and a tangential tensile/thrust component acting upon the lateral regions of the book block back in order to bend the printed sheets over is imparted thereon. A drive for lowering the molding tool onto the book block back and for raising the molding tool for the return stroke into the central position is provided in order to optimize the pressing process and to reduce the structural outlay and to reduce the setup time. The molding tool is vertically displaceable in the carriage via an operating cylinder which can be actuated by compressed air. The pressing force is adjustable via the compressed air and is controlled in such a manner that, in the central position, the molding tool acts upon the back of the book block with a pressing force which is reduced in relation to the pressing force applied in the pivoting position.</p> |
