Apparatus for cutting off a tear-open strip

An apparatus for severing a tear-open strip from a band of material with a width equal to the length of said strip and for applying said strip to an intermittently conveyed web of packaging material which extends substantially transversely relative to said band comprising:

• two knife means for cooperatively cutting a said strip from a said band, said knife means each being provided with a cutting edge, one of said knife means being stationary and housing a support and guide surface for said band and the other of said knife means having a longitudinal axis and being movable with respect to said stationary knife means for severing said strip from said band, said other knife means having openings in a surface adjacent to its cutting edge, said openings being subjected to suction for holding and transporting said severed strip, wherein said cutting edges of said knife means form chords of a hyperboloid of revolution and are inclined relative to each other to provide a drawing-type cutting of said strip from said band;
• means for pivoting said movable knife means through a predetermined angle about a longitudinal axis of said movable knife means, said longitudinal axis being arranged such that at one end position of pivot of the movable knife means said surface having said openings is in the plane of said web, and at the other end position of pivot said movable knife means presents a cutting edge inclined relative to the cutting edge of the stationary knife means for cooperating therewith to begin the draw-down severing of said strip;
• and
• means for displacing said movable knife means during its travel from the first end position to the other end position so that said cutting edges are out of engagement during said travel.