Method and apparatus for separating a pane of brittle material from a moving ribbon of the material

Abstract

A pane is separated from a moving ribbon of brittle material by restraining the ribbon upstream of a score line prior to separating the pane. The ribbon is restrained by selectively contacting a first side and a second side of the ribbon in one of an opposite, overlapping or offset relation. The ribbon can be restrained prior to, substantially simultaneous with or subsequent to forming the score line. The restrained status of the ribbon is maintained during and immediately after separation of the pane from the ribbon, thereby reducing the introduction of a disturbance or bending moment into the upstream ribbon.

1 . A method of separating a pane from a moving ribbon of brittle material, the method comprising: 
 a. contacting a first side of the moving ribbon with an upstream press bar and contacting a second side of the moving ribbon with an upstream backing bar, the upstream press bar and the upstream backing bar moving with the ribbon to restrain a portion of the ribbon portion of the ribbon; and    b. separating the pane from the ribbon along a score line downstream of the restrained portion of the ribbon.    
   
   
       2 . The method of  claim 1 , further comprising releasing the restrained portion of the ribbon after separating the pane from the ribbon.  
   
   
       3 . The method of  claim 1 , further comprising forming the score line prior to restraining the portion of the ribbon.  
   
   
       4 . The method of  claim 1 , further comprising forming the score line subsequent to restraining the portion of the ribbon.  
   
   
       5 . The method of  claim 1 , further comprising offsetting the upstream press bar and the upstream backing bar along a length of the ribbon.  
   
   
       6 . The method of  claim 1 , further comprising locating the upstream press bar opposite the upstream backing bar.  
   
   
       7 . The method of  claim 1 , further comprising contacting the upstream backing bar against the second side of the ribbon opposite the score line.  
   
   
       8 . The method of  claim 1 , further comprising employing a portion of the upstream backing bar as a scoring anvil.  
   
   
       9 . The method of  claim 1 , further comprising forming the score line in the first side of the ribbon opposite a portion of the upstream backing bar.  
   
   
       10 . The method of  claim 1 , further comprising urging a downstream press bar against the first side of the ribbon downstream of the score line to induce separation along the score line.  
   
   
       11 . The method of  claim 1 , further comprising contacting a secondary upstream backing bar with a second side of the ribbon prior to separating the pane from the ribbon.  
   
   
       12 . The method of  claim 1 , further comprising contacting a secondary upstream backing bar with a second side of the ribbon prior to forming the score line.  
   
   
       13 . The method of  claim 1 , further comprising overlapping the upstream press bar and the upstream backing bar along the ribbon.  
   
   
       14 . The method of  claim 1 , further comprising restraining the portion of the ribbon after separating the pane along the score line.  
   
   
       15 . The method of  claim 1 , further comprising contacting a secondary upstream backing bar with a second side of the ribbon, and contacting the upstream press bar with the first side of the ribbon prior to separating the pane.  
   
   
       16 . The method of  claim 1 , further comprising creating a compressive stress in the first side of the ribbon transverse to the score line.  
   
   
       17 . An apparatus for separating a pane from a moving ribbon of brittle material, the apparatus comprising: 
 a. a pair of opposing bars contacting opposing sides of the ribbon and moving with the ribbon, to restrain a portion of the ribbon upstream of a score line; and    b. a downstream press bar contacting the ribbon downstream of a score line to separate the pane from the ribbon along the score line.    
   
   
       18 . The apparatus of  claim 17  wherein the opposing bars are in an offset relation.  
   
   
       19 . The apparatus of  claim 17  wherein the opposing bars are in an opposite relation.  
   
   
       20 . The apparatus of  claim 17 , wherein the opposing bars contact the ribbon along substantially an entire length of the score line.