Method and device for detecting a fiber lap as well as a fiber cutting machine

A device for detecting a fiber lap on a rotating machine component, comprising

• a sensor unit for generating a sensor signal and positioned in spaced relationship to the rotating component so as to define an open space between the rotating component and the sensor unit, such that the sensor signal strikes the circumference of the rotating component, and
• wherein the sensor unit comprises an ultrasonic transmitter for generating the sensor signal as a sound signal in the ultrasound frequency range, and a sound receiver for receiving an echo signal which is reflected from the rotating component.

A fiber cutting machine for cutting a tow into defined lengths, comprising

• a rotatable cutting blade holder having an annular channel for receiving an advancing tow during rotation of the holder, and with a plurality of cutting blades spaced about the circumference of the annular channel,
• a rotatable pressure ring which is configured to rotate with the cutting blade holder and feed the advancing tow into the channel so as to be cut by the cutting blades, and
• a device for detecting a fiber lap on the rotatable pressure ring comprising a sensor unit for generating a sensor signal and positioned in spaced relationship to the rotatable pressure ring so as to define an open space between the rotating pressure ring and the sensor unit, such that the sensor signal strikes the circumference of the pressure ring, and wherein the sensor unit comprises an ultrasonic transmitter for generating the sensor signal as a sound signal in the ultrasound frequency range, and a sound receiver for receiving an echo signal which is reflected from the pressure ring.