Reversible nip roller drive system

Abstract

A reversible nip roller drive system for delivering an elongated band, tape, strap or the like in both a forward and reverse direction as required, with one nip roller of each set of paired nip rollers being translatable between an open and closed position, the nip rollers being connected to associated nip pulleys. The nip pulleys are driven by an interconnected drive belt, preferably toothed, mounted on pulleys or sheaves. The system has a drive pulley, two pairs of nip pulleys connected to the nip rollers, each pair having a fixed pulley and a linearly translatable pulley, and a linearly translatable idler pulley. The drive pulley and the two nip pulleys on one side of the band are stationary or fixed in place, whereas the idler pulley and the opposing nip pulleys are simultaneously linearly translatable relative to the other pulleys, the idler pulley being disposed to same side of the band as the drive pulley, and the opposing nip pulleys being disposed on the opposite of the band from the other nip pulleys.

1 . A reversible nip roller drive system comprising:
 a stationary drive pulley;   a linearly translatable idler pulley;   two pairs of nip pulleys, wherein for each of said pairs one nip pulley of said pair is stationary and the other nip pulley of said pair is linearly translatable in the same direction as said idler pulley;   a belt interconnecting said drive pulley, said idler pulley, said stationary nip pulleys and said translatable nip pulleys, whereby rotation of said drive pulley results in rotation of said idler pulley and said nip pulleys;   wherein said drive pulley and said idler pulley are positioned on the opposite side of said nip pulleys from said translatable nip pulleys, and wherein the separation distance between said drive pulley and said idler pulley is greater than the separation distance between said pairs of nip pulleys, such that the belt pathway from said drive pulley to one of said stationary nip pulleys is parallel to the belt pathway from said idler pulley to the other of said stationary nip pulleys;   wherein said idler pulley and said translatable nip pulleys are simultaneously translatable to increase and decrease the separation distance between said stationary nip pulleys and said translatable nip pulleys.   
   
   
       2 . The system of  claim 1 , further comprising a translatable mounting bracket, and wherein said translatable nip pulleys and said translatable idler pulley are mounted onto said translatable mounting bracket. 
   
   
       3 . The system of  claim 1 , said pulleys having ridges and grooves and said belt having ridges and grooves. 
   
   
       4 . The system of  claim 1 , said pulleys comprising gears and said belt comprising a chain. 
   
   
       5 . The system of  claim 1 , wherein the combination of said belt and said pulleys define a belt pathway;
 whereby when said separation distance between said stationary nip pulleys and said translatable nip pulleys is increased, the length of said belt pathway between said translatable idler pulley and one of said stationary nip pulleys shortens, and the length of said belt pathway between said translatable nip pulley and said stationary drive pulley lengthens; and further   whereby when said separation distance between said stationary nip pulleys and said translatable nip pulleys is decreased, the length of said belt pathway between said translatable idler pulley and one of said stationary nip pulleys lengthens, and the length of said belt pathway between said translatable nip pulley and said stationary drive pulley shortens.   
   
   
       6 . The system of  claim 5 , wherein the increase in the overall length of said belt pathway under maximum separation of said stationary nip pulleys and said translatable nip pulleys is approximately two percent of the separation distance. 
   
   
       7 . A reversible nip roller drive system in an apparatus having nip rollers driving a band in either of two opposite directions, said system comprising:
 a stationary drive pulley;   a linearly translatable idler pulley;   two pairs of nip pulleys connected to said nip rollers, wherein for each of said pairs one nip pulley of said pair is stationary and the other nip pulley of said pair is linearly translatable in the same direction as said idler pulley, wherein said stationary nip pulleys are positioned on one side of said band and said translatable nip pulleys are positioned on the opposite side of said band;   a belt interconnecting said drive pulley, said idler pulley, said stationary nip pulleys and said translatable nip pulleys, whereby rotation of said drive pulley results in rotation of said idler pulley and said nip pulleys;   wherein said drive pulley and said idler pulley are positioned on the opposite side of said band from said translatable nip pulleys, and wherein the separation distance between said drive pulley and said idler pulley is greater than the separation distance between said pairs of nip pulleys, such that the belt pathway from said drive pulley to one of said stationary nip pulleys is parallel to the belt pathway from said idler pulley to the other of said stationary nip pulleys;   wherein said idler pulley and said translatable nip pulleys are simultaneously translatable to increase the separation distance between said stationary nip pulleys and said translatable nip pulleys.   
   
   
       8 . The system of  claim 7 , further comprising a translatable mounting bracket, and wherein said translatable nip pulleys and said translatable idler pulley are mounted onto said translatable mounting bracket. 
   
   
       9 . The system of  claim 7 , said pulleys having ridges and grooves and said belt having ridges and grooves. 
   
   
       10 . The system of  claim 7 , said pulleys comprising gears and said belt comprising a chain. 
   
   
       11 . The system of  claim 7 , wherein said translatable idler pulley and said translatable nip pulleys translate in a direction perpendicular to said band. 
   
   
       12 . The system of  claim 7 , wherein the combination of said belt and said pulleys define a belt pathway;
 whereby when said separation distance between said stationary nip pulleys and said translatable nip pulleys is increased, the length of said belt pathway between said translatable idler pulley and one of said stationary nip pulleys shortens, and the length of said belt pathway between said translatable nip pulley and said stationary drive pulley lengthens; and further   whereby when said separation distance between said stationary nip pulleys and said translatable nip pulleys is decreased, the length of said belt pathway between said translatable idler pulley and one of said stationary nip pulleys lengthens, and the length of said belt pathway between said translatable nip pulley and said stationary drive pulley shortens.   
   
   
       13 . The system of  claim 12 , wherein the increase in the overall length of said belt pathway under maximum separation of said stationary nip pulleys and said translatable nip pulleys is approximately two percent of the separation distance.