Device and method for transporting and separating blanks from a material web

Abstract

The invention relates to a device (100) for transporting and separating blanks (1010) from a material web (1000), comprising a vacuum cylinder (8) for transporting the blanks (1010), a vacuum transport cylinder (7) for further transporting the blanks (1010), and a control unit (9). According to the invention, the vacuum cylinder (8) has a pivotable vacuum segment (82) and a rotary actuator (85) is provided for rotating the vacuum segment during operation. This makes it possible to reduce the effective vacuum region on a surface of the vacuum cylinder (8). The invention also relates to a method for transporting and separating blanks from a material web. A device and method enable a gentler and more accurate transfer of blanks from a vacuum cylinder to a vacuum transport cylinder.

What is claimed is: 
     
         1 . A device for transporting and separating blanks from a material web, comprising a vacuum cylinder for transporting the blanks,
 a vacuum transport cylinder arranged downstream thereof for further transporting the blanks,   with a further downstream transfer level (E) for taking over the blanks from the vacuum transport cylinder,   and with a control unit,   characterized in that   the vacuum cylinder has a pivotable vacuum segment which extends over an angular range of the vacuum cylinder for applying vacuum to the surface of the vacuum cylinder, and that   a rotary actuator is provided for rotating the vacuum segment,   wherein the rotary actuator is connected to the control unit by means of data transmission technology.   
     
     
         2 . The device according to  claim 1 , wherein at least one movement profile for the rotary actuator is stored in the control unit. 
     
     
         3 . The device according to  claim 1 , wherein the pivot axis of the vacuum segment lies in the axis of rotation of the vacuum cylinder. 
     
     
         4 . The device according to  claim 3 , wherein the vacuum segment extends over an angular range of 180-300° of the vacuum cylinder, in particular from 250-290°. 
     
     
         5 . The device according to  claim 1 , wherein the vacuum segment is formed by a sector which is open toward the outer surface of the vacuum cylinder and is rotatably mounted within the vacuum cylinder,
 or that the vacuum cylinder has supply channels distributed evenly around its circumference and the vacuum segment is formed by at least one control disc which can connect the supply channels to a vacuum system.   
     
     
         6 . The device according to  claim 1 , wherein at least the vacuum cylinder is equipped with a controllable rotary drive. 
     
     
         7 . The device according to  claim 1 , wherein the device is equipped with:
 a material web feeding mechanism for transporting a material web, and/or a punching cylinder and a counter-punching cylinder for punching blanks from the material web upstream of the vacuum cylinder and/or the vacuum transport cylinder, and/or   a vacuum transport cylinder with an adhesion-optimized surface, and/or if the material web is multi-layered, with at least one carrier layer and a product layer, with a delamination unit for separating the blanks from the carrier layer, and/or   a mechanism for removing the punching residues and, if necessary, the carrier layer, and/or   a conveyor belt or a conveyor system with product receptacles in the transfer level (E) for further conveying the blanks or,   with a product web in the transfer level (E) for receiving the blanks.   
     
     
         8 . A method for transporting and separating blanks from a material web, comprising the following steps:
 a) feeding a material web with blanks,   b) transporting the blanks on a vacuum cylinder,   c) transferring the blanks to a vacuum transport cylinder, and   d) transporting the blanks on the vacuum transport cylinder,   e) transferring the blanks to a transfer level (E),   wherein, in step c), the effective vacuum region on a surface of the vacuum cylinder is reduced during the transfer of a respective blank.   
     
     
         9 . The method according to  claim 8 , wherein the vacuum cylinder has a vacuum segment which extends over an angular range of the vacuum cylinder for applying vacuum to its outer surface, and the vacuum segment is pivoted in step c) against the direction of rotation (R) of the vacuum cylinder. 
     
     
         10 . The method according to  claim 9 , wherein the vacuum segment starts to rotate against the direction of rotation (R) as soon as at least 20%, in particular at least 40%, of the area of a respective blank has been transferred from the vacuum cylinder to the vacuum transport cylinder and is held by the latter. 
     
     
         11 . The method according to  claim 9 , wherein the vacuum segment is pivoted in the direction of rotation (R) of the vacuum cylinder before a respective subsequent next blank is transferred from the vacuum cylinder to the vacuum transport cylinder. 
     
     
         12 . The method according to  claim 8 , wherein in step c), during the start of the transfer of a respective blank from the vacuum cylinder to the vacuum transport cylinder, the vacuum cylinders rotate synchronously with the vacuum transport cylinder. 
     
     
         13 . The method according to  claim 8 , wherein the vacuum transport cylinder is moved at a constant rotational speed (R).