Sewing method and device

Abstract

A sewing mechanism is provided with: a post bed and sewing needles, wherein an article to be sewn is interposed between the post bed and the sewing needles. When the post bed comes closer to the article to be sewn than that in the previous sewing by at least a predetermined distance, in other words, when a separation distance between the article to be sewn and the post bed becomes less than that in the previous sewing by at least a predetermined distance, a thread pulling mechanism pulls threads hooked in needle holes of the sewing needles in a direction away from the post bed.

What is claim is: 
     
         1 . A sewing method for forming stitches on an article to be sewn, using a needle configured to pierce or withdraw from the article to be sewn in accordance with repetition of back and forth movement, and a looper that faces the needle with the article to be sewn therebetween and is housed inside a post bed, the sewing method comprising
 when the post bed has become closer to the article to be sewn by at least a prescribed amount than in immediately preceding sewing, pulling a thread hooked on the needle in a direction away from the post bed, or, when the post bed has become farther from the article to be sewn by at least a prescribed amount than in the immediately preceding sewing, pulling the thread hooked on the needle in a direction toward the post bed.   
     
     
         2 . A sewing device that forms stitches on an article to be sewn, using a needle configured to pierce or withdraw from the article to be sewn in accordance with repetition of back and forth movement, and a looper that faces the needle with the article to be sewn therebetween and is housed inside a post bed, the sewing device comprising:
 a thread pulling mechanism configured to pull a thread , which has been hooked on the needle, in a direction away from or toward the post bed; and   a control section configured to perform control to operate the thread pulling mechanism when a distance between the post bed and the article to be sewn differs by at least a prescribed amount from a distance in immediately preceding sewing.   
     
     
         3 . The sewing device according to  claim 2 , wherein:
 the thread pulling mechanism is a pushing device configured to push the thread.   
     
     
         4 . The sewing device according to  claim 3 , wherein the pushing device is formed from a cylinder device including a rod, and pushes the thread with the rod. 
     
     
         5 . The sewing device according to  claim 2 , wherein
 the thread pulling mechanism is a winding device configured to wind the thread.   
     
     
         6 . The sewing device according to  claim 5 , wherein
 the winding device also functions as a thread supplying section configured to supply the thread.   
     
     
         7 . The sewing device according to  claim 5 , wherein
 the winding device is formed from a rotary actuator including a rotating cylinder, and the thread is wound on the rotating cylinder.