Roll feeder with a traction unit

Abstract

A roll feeder for feeding a steel sheet to a processing machine for processing is disclosed to include a rack, which has a hub that supports a roll of steel sheet and is rotated to let off the steel sheet, a roll feeding unit, which has sheet-transfer roller sets for transferring the steel sheet from the rack to the processing machine and a roller leveler for leveling the steel sheet, and a traction unit, which is provided between the rack and the roll feeding unit and controlled to pull the steel sheet from the hub to the roll feeding unit.

1 . A roll feeder comprising: 
 a rack, said rack comprising a hub adapted to support a roll of steel sheet and to let off the steel sheet;    a roll feeding unit adapted to transfer the steel sheet from said rack, said roll feeding unit comprising sheet-transfer roller set means adapted to transfer the steel sheet, and a roller leveler adapted to level the steel sheet; and    a traction unit provided between said rack and said roll feeding unit and adapted to pull the steel sheet from said hub to said roll feeding unit.    
   
   
       2 . The roll feeder as claimed in  claim 1 , wherein said traction unit comprises a track extending between said rack and said roll feeding unit, and a tractor movable between two distal ends of said track and adapted to pull the steel sheet from said hub to said roll feeding unit.  
   
   
       3 . The roll feeder as claimed in  claim 2 , wherein said tractor comprises jaw means adapted to seize the steel sheet from said hub.  
   
   
       4 . The roll feeder as claimed in  claim 2 , wherein said tractor comprises hook means adapted to catch the steel sheet from said hub.  
   
   
       5 . The roll feeder as claimed in  claim 1 , wherein said traction unit comprises a material receiver, said material receiving having a material entrance for receiving the steel sheet from said hub, said material entrance having a width gradually increasing toward said rack  
   
   
       6 . The roll feeder as claimed in  claim 2 , wherein said traction unit further comprises a plurality of sprockets arranged around said track, a transmission chain mounted on said sprockets and fastened to said tractor for moving said tractor along said track upon rotation of said sprockets.  
   
   
       7 . The roll feeder as claimed in  claim 2 , wherein said tractor comprises a body, said body having an opening, a toothed fixed jaw and a toothed movable jaw provided inside the opening of said body.  
   
   
       8 . The roll feeder as claimed in  claim 6 , wherein said material receiver comprises two swinging frames bilaterally pivoted to said traction unit, said swinging frames each having a curved panel, the two curved panels of said swinging frames being arranged in a double-bevel manner.  
   
   
       9 . The roll feeder as claimed in  claim 7 , wherein said toothed movable jaw is pivotally mounted in the opening of said body.  
   
   
       10 . The roll feeder as claimed in  claim 2 , wherein said traction unit further comprises a plurality of guide rollers mounted in said track and adapted to guide the steel sheet forwards.  
   
   
       11 . The roll feeder as claimed in  claim 2 , further comprising a rammer installed in said track and adapted to flatten the steel sheet.  
   
   
       12 . The roll feeder as claimed in  claim 11 , wherein said rammer comprises a fixed bottom die, and a movable upper ramming die vertically movable relative to said fixed bottom die.  
   
   
       13 . The roll feeder as claimed in  claim 2 , further comprising a pressure roller installed in said track and adapted to stop the steel sheet from curving upwards.  
   
   
       14 . The roll feeder as claimed in  claim 2 , wherein said tractor comprises a peg adapted to hook in a hole in the lead end of the steel sheet being let off from said hub.  
   
   
       15 . The roll feeder as claimed in  claim 1 , wherein said sheet-transfer roller set means of said roll feeding unit comprises a first sheet-transfer roller set and a second sheet-transfer roller set, and said roller leveler is set between said first sheet-transfer roller set and said second sheet-transfer roller set.  
   
   
       16 . The roll feeder as claimed in  claim 1 , wherein said rack further comprises an expander installed in said hub and adapted to expand the roll of steel sheet being loaded on said hub.  
   
   
       17 . The roll feeder as claimed in  claim 1 , wherein said rack further comprises limiter disposed at one side of said hub and adapted to limit the position of the steel sheet being loaded on said hub.  
   
   
       18 . The roll feeder as claimed in  claim 1 , wherein said rack further comprises a holding down device disposed at one side of said hub and adapted to hold down a roll of steel sheet on said hub.  
   
   
       19 . The roll feeder as claimed in  claim 1 , wherein said rack further comprises a lifting support spaced below said hub and adapted to support the lead end of the steel sheet being loaded on said hub.