GB1199337A - Thread Cutter for an Electrically Operated Sewing Machine - Google Patents

Abstract

1,199,337. Sewing machines. GROSVENOR DRESS CO. (NORTHAMPTON) Ltd. and C. J. GOOSEY. 20 Jan., 1969 [19 Jan., 1968], No. 3004/68. Heading D1G. A sewing machine is provided with a threadcutting blade adapted to be actuated by a solenoid, the energising circuit of which contains a switch which is manually operable when the machine is stopped, and interrupter means so arranged that when the switch is closed the circuit is not completed unless the needle is disengaged from a workpiece being sewn and a loop of thread to be cut is positioned in the path of movement of the cutter blade. In a blindstitch sewing machine, a bracket 8, secured by screws 9 to the machine head, carries a solenoid 10. A lever 12 pivoted intermediately at 13 to bracket 8, carries at one end a knife blade 14 and is pivoted at its other end at 16 within the bifurcated end of the armature 11 of solenoid 10. A spring 17 biases armature 11 inwardly and blade 14 to an inoperative position. The circuit of solenoid 10 comprises a switch which is closed when a treadle, depresssed in one direction to start the machine, is reversely depressed when the machine is stopped. The circuit also comprises a pair of brushes 27 which are bridged by a conducting segment 22, carried by an insulating disc 20 rigid with the arm shaft of the machine, when the needle is raised and a loop of needle thread 5 extends across the path of movement of knife 14. The arrangement is thereby such that if brushes 27 are not initially bridged by segment 22 when the machine stops, the arm shaft is turned by means of the hand wheel 2 until such bridging occurs, when the treadle is reversely depressed. It is stated that segment 22 may be combined with means for stopping the machine with the needle raised.