Throat plate for a sewing machine

Claim 1

IN A SEWING MACHINE, IN COMBINATION WITH A SLIDE PLATE AND A RECIPROCATORY NEEDLE, A THROAT PLATE COMPRISING, (A) A PLATE BODY HAVING A CUT-OUT, THE LONGITUDINAL AXIS OF WHICH EXTENDS IN A DIRECTION PARALLEL TO THE LINE OF FEED, (B) THERE BEING A PAIR OF GROOVES IN SAID PLATE BODY, ONE ADJACENT EACH END OF SAID CUT-OUT AND SAID GROOVES BEING IN LINEAR ALIGNMENT, (C) A SLIDE MEMBER SLIDEABLY RECEIVED IN SAID GROOVES AND BRIDGING SAID CUT-OUT, (D) SAID SLIDE MEMBER HAVING A PLURALITY OF PARALLEL FEED DOG SLOTS EXTENDING LONGITUDINALLY THEREOF AND TWO SPACED NEEDLE APERTURES, (E) SAID PLATE BODY HAVING IN ONE OF SAID GROOVES AN ELONGATED SCREW SLOT, (F) A LEAF SPRING EXTENDING TRANSVERSELY OF THE LINE OF FEED AND SECURED ON THE UNDERSIDE OF SAID PLATE BODY TO SAID MEMBER BY A SCREW PASSING THROUGH SAID SCREW SLOT AND ENGAGING IN A THREADED APERTURE IN SAID SLIDE MEMBER, (G) THE END OF SAID LEAF SPRING EXTENDING BEYOND THE EDGE OF SAID PLATE BODY AND IN A POSITION TO ENGAGE FRICTIONALLY AGAINST THE UNDERSIDE OF SAID SLIDE PLATE WHEN THE SAME IS IN JUXTAPOSITION TO SAID PLATE BODY, (H) SAID SLIDE MEMBER BEING SLIDEABLE TO SELECTIVELY EFFECT REGISTRATION OF EITHER OF SAID NEEDLE APERTURES WITH SAID NEEDLE, (I) THE FRICTIONAL ENGAGEMENT OF SAID LEAF SPRING END WITH THE UNDERSIDE OF SAID SLIDE PLATE RETAINING SAID SLIDE MEMBER IN A POSITION OF ADJUSTMENT.