Method and apparatus for forming element-free space portion in slide fastener chain

An apparatus for forming an element-free space portion in a continuous slide fastener chain having a pair of coupled rows of metallic discrete fastener elements mounted on and along confronting inner edges of fastener tapes, said apparatus comprising:

• (a) a base having a long and narrow central gap for guiding the continuous slide fastener chain in a longitudinal path;
• (b) a punch and a die situated above and under said central gap of said base for vertical movement to clamp a number of fastener elements, which exist in a space-forming section in the continuous fastener chain, at their coupling heads and to push the clamped fastener elements out of the space-forming section upwardly or downwardly;
• and
• (c) a pair of horizontally spaced cutting blades cooperative with said punch for cutting and scattering upper or lower legs of the fastener elements in a single cutting blade motion, said fastener elements clamped by said punch and said die at positions adjacent to their coupling heads, wherein each one of said cutting blades has a wedge-shape in cross section and a blade tip spaced laterally away from said punch and positioned between a center of a core of said fastener tape and said punch.