Thread control mechanism

Claim 1

IN A SEWING MACHING HAVING A ROTARY DRIVE SHAFT, STICH FORMING MEANS INCLUDING AT LEAST ONE STITCH FORMING ELEMENT, AND CONNECTIONS FROM THE DRIVE SHAFT FOR OPERATING SAID STITCH FORMING MEANS, THE COMBINATION WHICH INCLUDES A SOURCE OF THREAD SUPPLY, ROTARY THREAD PULL-OFF MEANS FOR PULLING THREAD FROM SAID SOURCE OF SUPPLY AND DELIVERING THE SAME TO SAID STITCH FORMING ELEMENT, SAID PULL-OFF MEANS HAVING A STRAIGHT CYLINDRICAL OUTER SURFACE ABOUT WHICH AT LEAST ONE TURN OF THREAD MAY BE WRAPPED, THREAD TENSIONING MEANS COOPERATING WITH SAID THREAD BETWEEN SAID THREAD PULL-OFF MEANS AND THE POINT AT WHICH SAID THREAD IS DELIVERED TO SAID STITCH FORMING ELEMENT, ONE-WAY DRIVING CONNECTIONS FROM SAID DRIVE SHAFT TO SAID PULL-OFF MEANS FOR CONTINUOUSLY ROTATING SAID PULL-OFF MEANS, SAID CONNECTIONS PERMITTING FREE ROTATION OF SAID PULL-OFF MEANS IN THE DIRECTION IN WHICH IT IS ROTATED BY SAID DRIVING CONNECTIONS INDEPENDENTLY OF THE OPERATION OF SAID DRIVING CONNECTIONS BUT PREVENTING REVERSE ROTATION OF SAID PULL-OFF MEANS, MEANS SPACED IN A DIRECTION PARALLEL WITH THE AXIS OF SAID PULL-OFF MEANS FOR DELIVERING THREAD TO SAID PULL-OFF MEANS AND FOR DIRECTING THREAD AWAY THEREFROM TO INSURE THE WRAPPING OF AT LEAST ONE COMPLETE TURN OF THE THREAD ABOUT SAID PULL-OFF MEANS, WHEREBY A CAPSTAN ACTION IN PULLING THE THREAD FROM SAID SOURCE OF SUPPLY IS PROVIDED AND AN ACCUMULATION OF A SMALL EXTRA AMOUNT OF THREAD ABOUT SAID PULLOFF MEANS IS PRODUCED WHEN THE THREAD SUPPLIED THEREBY EXCEEDS THE DEMAND OF SAID STITCH FORMING ELEMENT.