| 摘要 |
PROBLEM TO BE SOLVED: To provide a defective sewing detection device capable of detecting, by using a simple unit, slackening which occurs in a fixed direction when defective sewing occurs.SOLUTION: A defective sewing detection device 10 is mounted on a sewing machine 1 using a plurality of needles 4 and a plurality of threads L and detects defective sewing by the slackening of the thread L. The sewing machine 1 includes: a needle bar 3 which is provided with the plurality of needles 4 and is vertically moved; a take-up lever 5 which is provided at the upper part of the needle bar 3 and is vertically moved together with the needle bar 3; a thread feeder 6 which simultaneously feeds the threads L toward the take-up lever 5; and spools 7 holding the respective threads L. The threads L are fed from the spools 7 through the thread feeder 6 to the take-up lever located obliquely above and are fed to the needles 4 located approximately perpendicularly below. At the time of the occurrence of a defect in the thread L, the thread L between the take-up lever 5 and the thread feeder 6 causes a ballooning phenomenon outward when the take-up lever 5 is moved downward. A sensor 20 for detecting the slackening of the thread L outward is attached between the take-up lever 5 and the thread feeder 6. The defective sewing detection device 10 includes a control device 30 for determining that the defect occurs based on the detection by the sensor 20.SELECTED DRAWING: Figure 1 |
