Sewing machine feeding mechanism

Claim 1

A FEEDING MEHANISM IN A SEWING MACHINE ADAPTED TO STITCH THE EDGES OF A PLURALITY OF SPACED PIECES OF FLAT WORK MATERIAL PRESENTED INTERMITTENTLY TO SAID MACHINE AND MOVING THROUGH THE MACINE AT A GIVEN LINEAR SPEED WHICH COMPRISES UPPER AND LOWER TRACKS EXTENDING THROUGH THE SEWING AREA AND LOCATED ONE ABOVE THE OTHER IN A COMMON PLANE, A PAIR OF OPPOSED GRIPPING MEMBERS RIDING IN AND BETWEEN SAID TRACKS AT THE LINEAR SPEED OF THE WORK PIECES IN THE SEWING AREA, AT THE LINEAR SPEED OF THE BEING PIVOTALLY MOUNTED ADJACENT ITS TRAILING END FOR VERTICAL MOVEMENT OF ITS LEADING END IN THE OTHER TRACKS TOWARD AND AWAY FROM THE OTHER TRACK, RESILIENT MEANS NORMALLY URGING THE LEADING ENDS OF SAID TRACKS TOWARD ONE ANOTHER, SAID TRACKS BEING VERTICALLY SEPARABLE FROM ONE ANOTHER TO ACCOMMODATE THE THICKNESS OF SAID WORK PIECES BUT URGED TOGETHER BY SAID RESILIENT MEANS AND PRESSING THE GRIPPING MEMBERS TOWARD AND INTO CONTACT WITH ONE ANOTHER AHEAD OF THE SEWING AREA WHEN NO WORK PIECE IS LOCATED BETWEEN THEM, SAID GRIPPING MEMBERS BEING ADAPTED TO CONVERGE AND GRIP THE SPACED WORK PIECES BETWEEN THEM AHEAD OF THE SEWING AREA AND THEN MOVE THROUGH THE SEWING AREA IN SAID TRACKS WITH THE EDGE TO BE STITCHED HELD FLAT AND PRESENTED FOR STITCHING DURING THE SEWING OPERATION.