Vorrichtung zum vereinzeln von in einem stapel vorgehaltenen blättern

Abstract

In a device for separation of sheets kept in a stack, pickup devices exert a pickup effect on the stack in order to push the upper sheets of the stack in overlapping fashion toward a separation device, which separates the uppermost sheet pushed forward the farthest from the following second sheet. The distance between the stack and the separation device can be adjusted as a function of the sheet quality and/or ambient conditions determined by sensors, like humidity and temperature.

1 . Device for separation of sheets held in a stack, with pickup devices that exert a pickup effect on the stack and push the upper sheets of the stack in overlapping fashion from the stack on this account, in which the advance path of the uppermost sheet diminishes relative to the following sheets, and with a separation device that separates the uppermost sheet advanced farthest forward from the following second sheet, characterized by the fact that the distance between the stack and the separation device is variably adjustable as a function of the sheet quality and/or ambient conditions determined by sensors.  
   
   
       2 . Device according to  claim 1 , characterized by the fact that the distance can be automatically adjusted by means of a controlled adjustment drive.  
   
   
       3 . Device according to  claim 2 , characterized by the fact that the adjustment drive has a linear drive that moves the stack or separation device.  
   
   
       4 . Device according to  claim 2  or  3 , characterized by the fact that the adjustment device is computer-controlled and especially has a stepping motor.  
   
   
       5 . Device according to one of the preceding claims, characterized by the fact that the humidity is determined by sensors as a control quantity.  
   
   
       6 . Device according to one of the preceding claims, characterized by the fact that the ambient temperature is determined by sensors as a control quantity.  
   
   
       7 . Device according to one of the preceding claims, characterized by the fact that the values of the ambient conditions determined by sensors are fed to a computer that calculates the control quantity for optimal spacing of the stack and separation device.  
   
   
       8 . Device according to  claim 7 , characterized by the fact that the computer calculates the control value for optimal spacing as a function of the values characterized by sheet quality.  
   
   
       9 . Device according to  claim 8 , characterized by the fact that the values characterizing the sheet quality can be manually entered in the computer.  
   
   
       10 . Device according to  claim 8 , characterized by the fact that the values characterizing the sheet quality are automatically determined at the beginning of separation in a learning cycle.  
   
   
       11 . Device according to  claim 1 , characterized by the fact that the distance can be adjusted manually.  
   
   
       12 . Device according to  claim 11  and one of the  claims 2  to  7 , characterized by the fact that the distance can be adjusted manually as a function of sheet quality and can be automatically adjusted in controlled fashion as a function of ambient conditions determined by sensors.