| 摘要 |
PROBLEM TO BE SOLVED: To improve dimensional accuracy after being sewn up, and stabilize tensile force of a sewing thread by sewing up mutual end surfaces of canvas arranged on a work stand by a sewing machine, and controlling so as to move the work stand at a constant speed at that time when the canvas for a belt is joined in an endless shape. SOLUTION: After canvas 3 for a belt is placed on a work stand 2 in a condition where its end surfaces are butted against or superposed on each other, a switch 9 of a sewing machine is turned on, and when a foot switch 10 to move the work stand 2 is stepped, a motor 5 is rotated, and the work stand 2 can move at a constant speed through a belt 7. In this movement, a joining part of the canvas 3 is sewn at a predetermined constant sewing pitch by the sewing machine 4. In this case, the motor 5 is formed of a motor to which an inverter is connected, and when a sewing speed of the sewing machine changes since a thickness or the like of the canvas changes, a frequency of the motor 5 is changed by the inverter, and dispersion of a sewing pitch is corrected by changing a moving speed of the work stand 2. |
