| 摘要 |
<p>Gripper thread lap indicator in lock stitch sewing machines to indicate a predetermined length of thread long before it is exhausted comprises a feeler mounted pivotally to sense the thickness of the thread lap on the gripper bobbin, the feeler being interconnected with a signal generator to produce a signal depending on the preset position of the feeler. Feeler is connected to low voltage electric supply to produce an optical signal.</p> |
