Optimization of the Thread Take-up Lever Mechanism in Lockstitch Sewing Machine Using the Imperialistic Competitive Algorithm

Lockstitch sewing machine is one of the mostcommon apparel industrial machines. the thread take-uplever mechanism of a sewing machine has an important rolefor proper stitch forming and smooth working of themachine. acquiring a mechanism with optimized geometry isof great importance to reach this goal. therefore, in thisstudy the optimization of the thread take-up lever mechanismwith respect to some important features such as the optimalpath of the coupler point and variation of coupler pointacceleration (jerk) is presented. modification of the objectivefunction with respect to the jerk is applied to assure smoothmovement of the thread take-up lever during sewing process.for this purpose, the imperialistic competitive algorithm isused to find the optimal link lengths of the take-up levermechanism. the analysis results present further verify thatthe coupler point jerk in the optimized mechanism in thehorizontal direction has been decreased about 52 percentwithout any conflict in the consistent operation of differentparts of the sewing machine.