Strapping device and method for operation thereof

Abstract

A device for strapping lying stacks of printed products with a strap, as well as to a corresponding operating method. The device includes a handling device with two press jaws for pressing together and conveying the stack in a conveyor direction running in the stack longitudinal direction, from a stack formation region into a strapping region, as well as a strapping unit with a stack rest and with a strap channel. The strapping unit is traversable in an ejection direction running transversely to the conveyor direction. The strap channel is arranged in a plane orientated perpendicularly to the ejection direction. The strap channel includes a movable channel section, so that the strap channel may assume an open and a closed condition, wherein a stack in the open condition may be brought in the conveyor direction into a strapping region enclosed by the strap channel.

1 . A device for strapping lying stacks of printed products with a strap, comprising a handling device with two press jaws for pressing together and conveying the stack in a conveyor direction running in the stack longitudinal direction, from a stack formation region into a strapping region, as well as a strapping unit with a stack rest and with a strap channel, wherein the strapping unit is traversable in an ejection direction running transversely to the conveyor direction, and wherein the strap channel is arranged in a plane orientated perpendicularly to the ejection direction, said strap channel comprising a movable channel section, so that the strap channel may assume an open and a closed condition, wherein when said strap channel is in the open condition, a stack may be brought in the conveyor direction into a strapping region enclosed by the strap channel. 
   
   
       2 . The strapping device according to  claim 1 , further comprising a first drive for moving the handling device in the conveyor direction, a second drive for moving the strapping unit in the ejection direction, and a third drive for moving the movable channel section so as to opening and closing the strap channel. 
   
   
       3 . The strapping device according to  claim 2 , further comprising a control device for controlling the drives. 
   
   
       4 . The strapping device according to  claim 1 , wherein the strapping unit is traversable in the ejection direction by less than a stack width. 
   
   
       5 . The strapping device according to  claim 1 , wherein the stack rest is adapted to move the stack in the ejection direction in an active or passive manner, said stack rest comprising a roller carpet of driven and/or freely rotatable rollers that are arranged transversely to the ejection direction. 
   
   
       6 . The strapping device according to  claim 1 , further comprising a stationary intermediate storage for strapped stacks ( 2 ), said stationary intermediate storage, in the ejection direction, is arranged laterally of the stack rest. 
   
   
       7 . The strapping device according to  claim 6 , wherein the strapping unit may be displaced such that the rest surfaces of the stack rest and of the intermediate storage border one another and are aligned with one another in the ejection direction. 
   
   
       8 . The strapping device according to  claim 1 , wherein the handling unit comprises a linear guide arranged in the conveyor direction and along which the press jaws are traversable, wherein the press jaws are displaceable transversely to the linear guide, to release the stack. 
   
   
       9 . A method for strapping a stack, with a device according to  claim 1 , comprising the steps of:
 step a) feeding the stack in a conveyor direction running in the stack longitudinal direction, from the stack formation region into the strapping region;   step (b) selected from the group of steps consisting of:
 b1) traversing the strapping unit in and/or opposite the ejection direction, in order to bring the strap channel to at least one strapping position, in which the strapping channel encloses the strapping region; and, 
 b2) opening the movable channel section, should the strap channel following step a) already be located in a strapping position, and closing the movable channel section after step a); 
   step c) strapping the stack at at least one strapping position; and,   step d) traversing the strapping unit and/or the stack in the ejection direction, in order to bring the strapped stack into at least one release region, in which it is located laterally of the strapping region in the ejection direction.   
   
   
       10 . The method according to  claim 9 , wherein the strapping unit, after strapping the stack ( 2 ) at a first strapping position, is displaced relative to the stack, such that the strap channel is arranged at a second strapping position, and such that the stack is strapped afresh at the second strapping position. 
   
   
       11 . The method according to  claim 10 , wherein the strap channel, after step d), remains in the second strapping position, the movable channel section is opened for feeding a further stack and subsequently closed again, and the further stack is firstly strapped at the second strapping position and, subsequently, by displacing the strapping unit, is strapped at the first strapping position. 
   
   
       12 . The method according to  claim 9 , wherein the strapping unit in the ejection direction is traversed maximally by less than a stack width. 
   
   
       13 . The method according to  claim 9 , wherein the stack, after the strapping is released by the handling unit, is supported from below by the stack rest. 
   
   
       14 . The method according to  claim 10 , wherein the strapping unit in the ejection direction is traversed maximally by less than a stack width. 
   
   
       15 . The method according to  claim 11 , wherein the strapping unit in the ejection direction is traversed maximally by less than a stack width. 
   
   
       16 . The method according to  claim 10 , wherein the stack, after the strapping is released by the handling unit, is supported from below by the stack rest. 
   
   
       17 . The method according to  claim 11 , wherein the stack, after the strapping is released by the handling unit, is supported from below by the stack rest. 
   
   
       18 . The method according to  claim 12 , wherein the stack, after the strapping is released by the handling unit, is supported from below by the stack rest.