Method of manufacturing slide fastener chain bearing patterns

A method of manufacturing a slide fastener chain including a pair of continuous fastener tapes having their respective patterns matched with each other and two rows of continuous fastener elements mounted along the inner longitudinal edges thereof, the method comprising the steps of:

• (a) applying two series of alignment markers to the continuous fastener tapes at intervals longitudinally thereof with the respective patterns of the continuous fastener tapes matched with each other;
• (b) feeding the opposed continuous fastener tapes in side-by-side toward an element-attaching station;
• (c) detecting the corresponding alignment markers during the feed of the opposed continuous fastener tapes;
• (d) controlling the feed of the opposed fastener tapes in such a way as to let the fastener tapes continue to feed if the corresponding alignment markers prove to be in registry with each other, and to restrain the feed of the preceding fastener tape to thus bring the corresponding alignment markers into registry, if the corresponding alignment markers prove to be out of registry with each other;
• and
• (e) attaching the two rows- of continuous fastener elements to the inner longitudinal edges of the opposed fastener tapes at the element-attaching station, with the alignment markers in registry with each other.