Rotary hook for sewing machines

Claim 1

A HORIZONTAL AXIS ROTARY HOOK COMPRISING A CUPSHAPED HOOK BODY HAVING AN INTERNAL CIRCULAR RACEWAY AND A LOOP SEIZING BEAK, A STATIONARY BOBBIN CASE CARRIER HAVING A CYLINDRICAL SIDE WALL DEFINING A BOBBIN RECEIVING CAVITY AND A DISCONTINUOUS CIRCULAR BEARING RIB ON SAID SIDE WALL AND JOURNALED IN SAID RACEWAY FOR ROTATION OF SAID HOOK BODY RELATIVELY TO SAID BOBBIN CASE CARRIER, SAID BEAK HAVING A LOOP SEIZING POSITION RELATIVE TO SAID BOBBIN CASE CARRIER AND DIVIDING SAID BOBBIN CASE CARRIER DIAMETRICALLY INTO A CAST-ON SIDE AND A CAST-OFF SIDE, A LATERALLY EXTENDING LOOP CONTROLLING FLANGE ON THE TOP OF SAID SIDE WALL ON THE CAST-OFF SIDE OF SAID BOBBIN CASE CARRIER AND TERMINATING IN A FREE EDGE DISPOSED CLOSELY ADJACENT TO THE PATH OF TRAVEL OF SAID BEAK, SAID FLANGE HAVING A ROTATION RESTRAINING NOTCH FORMED IN THE FACE THEREOF AT SAID LOOP SEIZING POSITION FOR RECEIVING A ROTATION RESTRAINING FINGER AND HAVING A THREAD LOOP CLEARANCE NOTCH FORMED IN THE FREE EDGE THEREOF AND DEFINING A SMOOTH CONTINUATION OF SAID FREE EDGE, SAID THREAD LOOP CLEARANCE NOTCH INCLUDING A FIRST EDGE BEGINNING AT A POINT APPROXIMATELY FORTY DEGREES FROM SAID LOOP SEIZING POSITION ON THE CAST-OFF SIDE AND EXTENDING ON SUBSTANTIALLY A STRAIGHT LINE TOWARD THE INNERMOST PORTION OF SAID ROTATION RESTRAINING NOTCH AND TERMINATING IN A THROAT, AND A SECOND EDGE EXTENDING FROM SAID THROAT ON SUBSTANTIALLY A STRAIGHT LINE TOWARD A POINT IMMEDIATELY ADJACENT TO SAID LOOP SEIZING POSITION.