GB625343A - Improvements in and relating to power driven sewing machines - Google Patents

Abstract

625,343. Sewing - machines. TEXTILE MACHINERY INNOVATIONS, Ltd., and BLACKMAN, A. S. May 12, 1947, No. 12783. [Class 112] A power driven sewing-machine has a spring urged lever 7 adjacent the presser foot and a lever 13 held against the tension of a spring 19 by a portion of thread adjacent the needle thread tension device, the arrangement being such that failure of the bobbin thread causes the lever 7 to move against the spring 10 to close an electric circuit stopping the machine, and' failure of the needle thread causes the lever 13 to be rotated by its spring to operate a cam 12 to close an electric circuit stopping the machine. Failure of the bobbin thread permits the needle thread b to move the lever 7 into the position shown in Fig. 4 where contacts 81, 9<SP>1</SP> close the electric circuit and energise an electromagnet 11 keeping the circuit closed. Thread between the take-up lever and the tension device passes through a loop 14 in the lever 13, the normal thread tension holding the lever and cam so that the spring contacts 16, 17 are separated. Failure of the needle thread permits the lever and cam to be rotated by the spring 19, the cam pressing the contacts 16, 17 together (Fig. 2) to close the circuit stopping the machine. The material to be stitched is passed betwen spring loaded contacts so that the material coming to an end will also stop the machine. Visual or audible warning devices may be actuated simultaneously with the stopping of the machine which is effected either by shutting off the power supply or by declutching.