Device for monitoring yarn motion on a textile machine

DETAILED DESCRIPTION It is a primary objective of the invention to provide a sensing device for monitoring ballooning motion of travelling threads or yarns.
It is another object of the invention to provide such sensing devices adapted to produce A.
C.
voltage sensing signals.
It is a more specific object of the invention to provide sensing devices for producing modulated high frequency sensing signals, and electronic circuitry transforming such sensing signals into demodulated or D.
C.
output signals.
Now in order to implement the aforementioned objectives and others which will become more readily apparent as the description proceeds, the sensing device of the invention comprises a yarn guide structure forming a yarn channel surrounding the travelling yarn and provided with yarn motion responsive and non-responsive elements arranged in alternate sequence at said yarn guide structure in circumferential direction of the yarn channel.
In the following context the invention is illustrated referring to schematic drawings which represent various sensing devices and an electronic circuitry for evaluating the sensing signals.
The connections attached to the electrodes are not shown, for the sake of clearness.