Twin-needle sewing machine with guide means for simultaneously stitching a pair of concealed slide fastener stringers to a fabric

In a sewing machine for simultaneously stitching onto a fabric a pair of concealed slide fastener stringer tapes each carrying a row of elements along one of the longitudinal edges thereof, wherein the sewing machine is of the type having a pair of needles movable up and down with respect to a bed past a presser foot supported thereover for stitching material being fed in a predetermined direction, the improvement comprising a throat plate arranged under said presser foot so as to constitute a part of said bed, said throat plate having formed therein a pair of guide channels generally extending in said predetermined direction each for slidably accommodating said one longitudinal edge of one of the stringer tapes together with the row of elements carried thereon, said guide channels being generally parallel to each other, said throat plate having a pair of openings for the passage therethrough of the respective needles, said throat plate having a generally flat surface between said guide channels and disposed generally parallel to a flat surface of the presser foot to confine the other edge portion of each stringer tape flat against said fabric onto which the stringer tape is stitched.