Thread winding control mechanism for sewing machines

Claim 1

A LOCK STITCH SEWING MACHINE HAVING STITCH FORMING INSTRUMENTALITIES INCLUDING A NEEDLE AND A LOOP TAKER, A FLANGED BOBBIN JOURNALED RELATIVELY TO SAID LOOP TAKER, ACTUATING MEANS INTERCONNECTING SAID NEEDLE AND LOOP TAKER FOR INTERRELATED MOVEMENT AS IS REQUIRED FOR THE FORMATION OF LOCK STITCHES, A DRIVE MOTOR OPERATIVELY CONNECTED TO SAID ACTUATING MEANS, MEANS FOR REPLENISHING THREAD ON SAID BOBBIN IN PLACE RELATIVELY TO SAID LOOP TAKER DURING SAID INTERRELATED MOTION OF SAID NEEDLE AND LOOP TAKER, INCLUDING A BOBBIN WINDING MEMBER DRIVEN BY SAID ACTUATING MEANS AND SHIFTABLY SUPPORTED BETWEEN SAID LOOP TAKER AND SAID BOBBIN FOR MOVEMENT INTO AND OUT OF DRIVING RELATION WITH SAID BOBBIN, A THREAD SENSING MEMBER EXTENDING BETWEEN SAID BOBBIN FLANGES AND SHIFTABLE IN RESPONSE TO A PREDETERMINED QUANTITY OF THREAD WOUND ON SAID BOBBIN, AND INTERENGAGING SURFACES FORMED ON SAID THREAD SENSING AND BOBBIN WINDING MEMBERS SHIFTABLE INTO FRICTIONAL ENGAGEMENT IN RESPONSE TO THE SENSING OF A PREDETERMINED QUANTITY OF THREAD WOUND ON SAID BOBBIN FOR STALLING SAID DRIVE MOTOR WHEN SAID DRIVE MOTOR, SAID ACTUATING MEANS, AND SAID THREAD REPLENISHING MEANS ARE OPERATIVELY CONNECTED.