| 摘要 |
PROBLEM TO BE SOLVED: To surely pass a thread through a needle hole at the rising position of a needle bar. SOLUTION: In this automatic thread passing sewing machine provided with an upper thread arranging means M1 for arranging the top end of an upper thread (w) pulled out of an upper thread supply source w1 and extended over a needle bar thread guide w3 at the lower end of a needle bar w2 at a position across the front or back of a stitch hole w5 of a sewing needle w4 and a thread passing means M2 for executing the thread passing operation by taking the arranged upper thread (w) into the stitch hole w5, this sewing machine is provided with a vertical needle bar moving means M3 for moving the needle bar w2 to the prescribed thread passing position by vertically moving the needle bar w2 and a slack absorbing means M4 for absorbing the slack of the upper thread (w) arranged during or after the execution of the said vertical needle bar moving operation. Therefore, even when upper thread (w) extended over the needle bar thread guide w3 is slackened with the vertical move of the needle bar w2, the slack is absorbed by the operation of the slack absorbing means M4, the thread passing can be executed at the rising position of the needle bar w2 and nothing does not collide with the main body of sewing machine or the like.
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