Sewing method and device for same

Abstract

In a first step, a needle pierces into an object to be sewed by reciprocal motion and leaves from the object to be sewed after the tip of the needle has penetrated therethrough. At this time, the needle is placed in a state of being stopped relative to the object to be sewed. In a second step, the needle leaves from the object to be sewed. At this time, the needle is moved relative to the object to be sewed along a sewing direction (sewing line).

What is claim is: 
     
         1 . A sewing method for forming stitches on an article to be sewn, wherein a needle whose tip pierces and withdraws from the article to be sewn and a looper that faces the needle with the article to be sewn therebetween and is housed inside a post bed move in a sewing direction relative to the article to be sewn to form the stitches along a trajectory of the movement, the sewing method comprising:
 a first step of, in a state where the needle is stopped relative to the article to be sewn on the trajectory of the movement, causing the needle to perform back-and-forth motion in a manner to move toward and away from the article to be sewn, to thereby cause the needle to be withdrawn from the article to be sewn after the needle has pierced the article to be sewn; and   a second step of, in a state where the needle has been withdrawn from the article to be sewn, moving the needle relative to the article to be sewn in the sewing direction along the trajectory of the movement.   
     
     
         2 . The sewing method according to  claim 1 , wherein
 the article to be sewn is positionally fixed, and a trajectory of the back-and-forth motion of the needle in the first step is made linear.   
     
     
         3 . The sewing method according to  claim 1 , wherein
 the article to be sewn is moved, and a trajectory of the back-and-forth motion of the needle in the first step is made elliptical.   
     
     
         4 . The sewing method according to  claim 1 , wherein
 the first step is performed in a state where the post bed housing the looper is separated from the article to be sewn.   
     
     
         5 . The sewing method according to  claim 1 , wherein
 the second step is performed when the needle reaches a top dead center.   
     
     
         6 . A sewing device that forms stitches on an article to be sewn, wherein a needle whose tip pierces and withdraws from the article to be sewn and a looper that faces the needle with the article to be sewn therebetween and is housed inside a post bed move in a sewing direction relative to the article to be sewn to form the stitches along a trajectory of the movement, the sewing device comprising:
 a casing in which the needle and the post bed housing the looper are provided;   a transport device configured to move the casing; and   a control section configured to control the transport device, wherein   the control section brings the needle and the looper into a state of being stopped relative to the article to be sewn on the trajectory of the movement, and causes the needle to perform back-and-forth motion in a manner to move toward and away from the article to be sewn, to thereby cause the needle to be withdrawn from the article to be sewn after the needle has pierced the article to be sewn, and move the needle and the looper relative to the article to be sewn in the sewing direction along the trajectory of the movement when the needle has been withdrawn from the article to be sewn.   
     
     
         7 . The sewing device according to  claim 6 , wherein
 a trajectory of the back-and-forth motion of the needle is linear.   
     
     
         8 . The sewing device according to  claim 6 , wherein
 a trajectory of the back-and-forth motion of the needle is elliptical.   
     
     
         9 . The sewing device according to  claim 6 , wherein
 in a state where the post bed housing the looper is separated from the article to be sewn, the control section moves the needle and the looper relative to the article to be sewn in the sewing direction along the trajectory of the movement.   
     
     
         10 . The sewing device according to  claim 6 , wherein
 when the needle reaches a top dead center, the control section moves the needle and the looper relative to the article to be sewn in the sewing direction along the trajectory of the movement.