| 摘要 |
<p>The thread guide mechanism for the shuttle in a double backstitch sewing machine, esp. a swing arm machine for working leather, has a guide tooth on the shuttle housing at the needle hole against the shuttle point. The upper thread is fed from it from the needle eye during the gripping stage. The design reduces the shear loading on the upper thread and simplifies the sewing machine drive assembly. Suitably the thread is given an equal phase since wave movement from the needle and the shuttle. As the shear forces on the upper thread are very small, hand sewing thread can be used in the sewing machine.</p> |
