Shoulder strip forming apparatus

An apparatus for producing package elements for subsequent integration into a package, the apparatus including knives for cutting from an advancing web of packaging material strips having non-linear edges which face upstream and downstream with respect to the direction of web travel, the web having a width corresponding to the width of the strips to be produced, the apparatus including a pair of conveying sections, each of the conveying sections defining a transport path for a web of packaging material, the transport paths converging upstream of the strip-cutting knives, the apparatus also including means for selectively delivering one of a pair of webs of packaging material to the strip-cutting knives via a conveying section, an improved web-changing device comprising a fixed knife positioned between the two web transport paths upstream of the convergence thereof, the fixed knife having working surfaces which face in opposite directions and are disposed on adjacent sides of the two web transport paths, said web-changing device also comprising a pair of independently operable movable knives, said movable knives cooperating with said fixed knife for severing the end of a web of packaging material being delivered along respective of said web transport paths, said fixed and movable knives cooperating to sever the webs to form ends which correspond to the shape of a non-linear edge of the strips to be produced, said web-changing device further comprising means for selectively interrupting each of said web transport paths, said interrupting means deflecting packaging material being delivered along a transport path which has been interrupted.