Automatic sewing machine - uses time spans for fabric holder movement to give a constant sewing rhythm

摘要

In the control operation for an automatic sewing machine, where the fabric workpiece holder is moved in relation to the needle, an initial time span is set between the start time of the operating start signal and the time when the workpiece holder actually operates and a second time span is set for the workpiece holder movement. The workpiece holder is driven according to the values of the first and second time spans. The steps for each seam are pref. set seam by seam, for each seam in a pattern, and a series of pulses is calculated for each speed for all the seams. Subtraction data are stored matching the stitching pattern data for each seam. A detection system registers at least the movement direction or location of the fabric holder, and modifies the time of either the first or second time span according to the monitored movement direction or location. The setting stage is activated as the fabric holder is driven. The access to stored sewing pattern data is registered, and a time adjustment signal is generated according to at least either the movement direction or movement location in the data, and the position of the needle is detected. The time for the workpiece holder drive is modified within the stored pattern data according to the time adjustment signal and the needle position detection, seam by seam, and for each seam in the pattern. ADVANTAGE - The operation gives a constant sewing rhythm to give improved function and working speed, without damage to the fabric.