Device for threading a processing installation, such as a dryer

Abstract

A device for feeding web material through a processing installation comprises a conveyor belt which has a first segment and a second segment. An opening roller and a guiding surface are adapted for unfolding the conveyor belt by means of separating the first and second segments. A spreader roll is adapted to keep the conveyor belt unfolded while a tail of said web material is placed on said first segment. A folding roll is adapted for folding said second segment over said first segment for to enclose the tail in the conveyor belt. The spreader roll comprises a first roll portion, a second roll portion and a circumferential guiding track separating the roll portions. The first roll portion, which is adapted for supporting said first segment, has a cylindrical outer surface.

1 . A device for feeding web material through a processing installation, having a foldable conveyor belt, which conveyor belt is divided, along a longitudinal direction, into an essentially flat first segment and an essentially flat second segment, the device comprising:
 an opening member and a guiding surface is located downstream of the opening member as seen in a direction of the travel of the conveyor belt, the opening member and the guiding surface adapted for unfolding the conveyor belt by separating the first and second segments a spreader roll, which is located downstream of the guiding surface and is adapted to keep the conveyor belt unfolded while a tail of said web material is placed on said first segment,   a folding member located downstream of the spreader roll and adapted to fold said second segment over said first segment to enclose the tail in the conveyor belt,   wherein the spreader roll includes a first roll portion, a second roll portion and a circumferential guiding track separating the first roll portion from the second roll portion, said first roll portion adapted to support said first segment, said second roll portion adapted to support said second segment, the first roll portion having a cylindrical outer surface.   
   
   
       2 . The device according to  claim 1 , the device further comprising a holding belt located adjacent to the spreader roll and adapted to travel in parallel to the first segment of the conveyor belt, and the holding belt is adapted to hold the tail pressed against said first segment until said second segment is to be folded onto said first segment. 
   
   
       3 . The device according to  claim 2 , wherein said holding belt is adapted to travel over a first pulley and a second pulley, the second pulley being located downstream of the first pulley as seen in a direction of the travel of the conveyor belt, the first pulley having a cylindrical outer surface. 
   
   
       4 . The device according to  claim 3 , wherein the second pulley has a cambered outer surface. 
   
   
       5 . The device according to  claim 2 , wherein a driving mechanism is adapted for driving the holding belt. 
   
   
       6 . The device according to  claim 1 , wherein the outer surface of said second roll portion tapers outwardly from the guiding track. 
   
   
       7 . The device according to  claim 6 , wherein the outer surface of said second roll portion is one of a conical outer surface and a cambered outer surface. 
   
   
       8 . The device according to  claim 1 , wherein at least one of said first roll portion and said second roll portion is provided with knurling on its outer surface. 
   
   
       9 . A device to feed web material comprising:
 a foldable conveyor belt divided along a longitudinal direction into a first segment and a second segment;   an opening member;   a guiding surface downstream of the opening member in a direction of travel of the conveyor belt, wherein the opening member and the guiding surface unfold the conveyor belt by separating the first and second segments;   a spreader roll downstream of the guiding surface and arranged to keep the conveyor belt unfolded while a tail of said web material is placed on said first segment;   a folding member downstream of the spreader roll and arranged to fold said second segment over said first segment to enclose the tail in the conveyor belt;   wherein the spreader roll includes a first roll portion, a second roll portion and a circumferential guiding track separating the first roll portion from the second roll portion, said first roll portion supports the first segment, said second roll portion supports the second segment, and the first roll portion has a cylindrical outer surface.   
   
   
       10 . The device of  claim 9  wherein the device feeds the web material through a pulp dryer. 
   
   
       11 . The device of  claim 9  further comprising a holding belt adjacent the spreader roll and traveling parallel to the first segment of the conveyor belt, and said holding belt holds the tail against said first segment until said second segment is to be folded onto said first segment. 
   
   
       12 . The device according to  claim 11  wherein said holding belt travels over a first pulley and a second pulley, the second pulley is downstream of the first pulley and the first pulley has a cylindrical outer surface. 
   
   
       13 . The device according to  claim 12  wherein the second pulley has a cambered outer surface. 
   
   
       14 . The device according to  claim 11  further comprising a driving mechanism coupled to and driving the holding belt. 
   
   
       15 . The device of  claim 9  wherein the outer surface of said second roll portion tapers outwardly from the guiding track. 
   
   
       16  The device of  claim 15  wherein the outer surface of said second roll portion has at least one of a conical outer surface and a cambered outer surface. 
   
   
       17 . The device of  claim 9  wherein at least one of said first roll portion and said second roll portion has a knurled outer surface.