Apparatus for injection molding of continuous slide fastener chain

In combination with an injection molding apparatus of the type wherein a continuous slide fastener chain is manufactured by repeating the steps of moving a movable mold relative to a stationary mold to intermittently open and close the molds, injection molding a row of fastener elements on portions of a pair of stringer tapes introduced through and positioned between said molds when said molds are closed, and then interrupting the positioning of said stringer tapes and subsequently feeding the same when said molds are opened preparatory to an ensuing injection molding operation, the improvement which comprises:

• means for forming a projection on a portion of a runner molded together with said row of fastener elements at the time of injection molding;
• means for halting the introduction of said tapes into the spacing between said molds in response to detection of said projection;
• and
• means for retracting and tensioning said tapes already introduced in the spacing between said molds in order to position within said molds the portion of said tapes on which rows of fastener elements are to be subsequently injection molded, the posterior end of said runner previously molded on said tapes together with the rows of fastener elements serving as a standard for the positioning of said tapes.