Investigation of the Influence of Defects of Sewing Machine V-belt Drive on the Stitch Length

Abstract

One of the main demands for sewing garment quality is good-looking seams. The variations of the stitch length worsen the aesthetical qualities of sewing garment. The problem of stitch length stability can only be solved by correlating the parameters of sewn materials and the sewing equipment. The article analyses the tendencies of stitch length changes. Investigations are made to determine the relation between stitch length and geometrical shape of belts of sewing equipment. For measuring geometrical shape of the belt special device is created. The modeling of belt defects is made. The measures of the vibration are made using the defected belts. Attention is drawn to the determination of vibration influence on the stitch length. For research, fabrics of three different characteristics and composition were selected. The results obtained demonstrate that stitch length variation tendency is similar to the variation tendency of vibration caused by a corresponding belt. It was determinated, when using a defective belt the stitch length increases about 10 to 15 %. This tendency becomes especially sharp with increasing rotation frequency of the main shaft of sewing machine.