| 摘要 |
<p>A needle thread guide device for double ring stitch sewing machine is used for the case that a double ring stitch is formed by forming a plurality of needle thread loops below a fabric and allowing a looper to successively enter these needle thread loops. The needle thread guide device has a cam (8c) which is formed at a location near a thread receiving surface (8a) of a needle thread guide (8), so as to be integral with the needle thread guide (8). The cam applies a tensile force, immediately before a looper enters, to a needle thread loop (6Lr) of a left needle thread (6L) which the looper enters finally in plural needle threads (6R, 6L) being received and supported on the thread receiving surface (8a) of the needle thread guide (8), as a movable needle thread take-up (3) rocks upward relative to rising movement of right and left needles (1R, 1L) from a bottom dead point. With this construction, it is avoided that the looper erroneously enters the plural needle thread loops, and a predetermined stitch is therefore formed reliably without causing skip-stitch. <IMAGE></p> |
