Method of and apparatus for accordion folding of endless webs

Abstract

A method of and an apparatus for the folding of paper to produce accordion folds in which the web is engaged at each second groove previously formed in the web and moved at a speed matched to the feed of the web upwardly along a linear path and downwardly along an arcuate path so as to produce the accordion fold.

We claim:  
     
         1 . A method of accordion folding a continuous web of foldable material having a succession of equidistant grooves formed therein and separating panels of said web from one another, said method comprising the steps of: 
 (a) advancing said web longitudinally at a speed of advance;    (b) lifting said web in a region of each second groove, advancing said second groove at a speed matched to said speed of advance to forcibly fold the web at said second groove, and depositing a fold formed in the web at the second groove; and    (c) repeating step (b) after depositing each fold formed therein to collect said web as an accordion-folded set of said panels.    
     
     
         2 . The method defined in  claim 1  wherein said web is lifted exactly at each second groove by an entrainer extending across the web.  
     
     
         3 . The method defined in  claim 2  wherein said entrainer is initially displaced linearly and upwardly at an inclination to said web in a forward direction of travel thereof, and then said entrainer is displaced forwardly and downwardly.  
     
     
         4 . The method defined in  claim 3  wherein said entrainer is displaced along a circular path during its displacement downwardly.  
     
     
         5 . The method defined in  claim 1  wherein the fold is deposited along a circular arc-segmental path.  
     
     
         6 . An apparatus for accordion folding a continuous web of foldable material having a succession of equidistant grooves formed therein and separating panels of said web from one another, said web being advanced longitudinally at a speed of advance, said apparatus comprising a lifter engaging said web in a region of each second groove and a guide for said lifter formed on both sides of said web for lifting said web in said region of each second groove, advancing the respective second groove at a speed matched to the speed of advance to forcibly fold the web at each second groove and depositing the resulting fold formed at the second groove on a previously folded portion of said web.  
     
     
         7 . The apparatus defined in  claim 6  wherein the guide formed on each side of said web is a chain.  
     
     
         8 . The apparatus defined in  claim 7  wherein said lifter is a wire extending across said web.  
     
     
         9 . The apparatus defined in  claim 6  wherein said guide includes a sheet metal member on each said of said web, said lifter being guided in said sheet metal members.  
     
     
         10 . The apparatus defined in  claim 9  wherein said lifter is carried by support rollers.  
     
     
         11 . The apparatus defined in  claim 6  wherein said guide defines an upwardly inclined path for said lifter to a high point and then a generally circular arc segmental path from said high point downwardly.  
     
     
         12 . The apparatus defined in  claim 11  wherein said arc segmental path is defined by a rotary arm or rotary disk arrangement.  
     
     
         13 . The apparatus defined in  claim 6  wherein the spacing of lifters along said guide is variable.  
     
     
         14 . The apparatus defined in  claim 6 , further comprising a guide for said web provided with an abutment forming a stop for said web.  
     
     
         15 . The apparatus defined in  claim 14  wherein said guide or said step are height adjustable.  
     
     
         16 . The method defined in  claim 1  wherein said web is a paper.  
     
     
         17 . The method defined in  claim 16  wherein said paper has a corrugated core with cover sheets on opposite sides thereof.