METHOD AND DEVICE FOR FOLDING A BAND IN A CONTINUOUS ASSEMBLY OF ACCORDION PLEATS FORMING THREE PANELS

摘要

A method and apparatus for transferring a band at a predetermined speed V to a station for pre-marking two folding lines which define a central panel of each pleat and then subjecting the band over a short distance to abrupt deceleration to a speed V' such that V'/V=1/L, where L is the length of each pleat in the fully extended state and 1 is the length of the pleat after folding so as to form a pocket, the last two panels of each pleat being inserted beneath the first panel prior to folding-back and maintaining the pocket in a flat position on the band.