Strand responsive electrical switch

In combination with apparatus for advancing a plurality of individual tensioned textile strands along respective predetermined paths of travel, means for electrically signalling the occurrence of an improper operating condition of one of the advancing tensioned strands and comprising a plurality of devices corresponding to the number of strands with each said device comprising housing means defining a relatively thin and flat generally rectilinear package, guide means mounted from said housing means for engagement with a corresponding one of said strands and for pivotal movement relative to said housing means about a generally horizontal axis transversely of said housing means in the direction of the thin dimension of said package and in response to an improper operating condition of said corresponding one strand, light actuated electrical switching means within said housing means for electrically signalling the occurrence of illumination thereof, light source means within said housing means for illuminating said switching means, and shutter means mounted within said housing means for movement in response to movement of said guide means and optically interposed between said switching means and said light source means for controlling the electrical signalling of said switching means in response to said occurrence;

• and said electrical signalling means further comprising means for mounting said plurality of devices in a stacked array adjacent said paths of travel and with said axes of said guide means substantially aligned.