| 摘要 |
An apparatus for monitoring the underthread in sewing machines, in which at least one signal generator is mounted in the path of the underthread and is disposed to generate an electric signal when the underthread is urged by means of a looper against the signal generator, and the generated signal is coupled to a signal monitoring circuit electrically connected to the signal generator device and is operable to shutdown the machine in response to a loss of said signals from said signal generator device. |
