Method of obtaining a thread running signal
AssigneeMaschinenfabrik Rieter AG
InventorsPeter Anderegg, Peter Oehy
Life of this patent
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Abstract
In a method of obtaining a thread tension signal a sensor in the form of a piezofoil is attached to a thread guide or to its mounting and delivers a signal which reflects, amongst other things, the oscillations induced in the thread guide by the thread movement. In order to obtain a signal which corresponds to the thread tension either the frequency of an element which winds up the thread and/or harmonics of this frequency is filtered out of the sensor signal and the level of this frequency or the level of these frequencies is measured.
Claims19
A method of measuring the tension in a running thread on a textile machine having means for winding said running thread, a thread guide for guiding said thread and a sensor connected to said thread guide for sensing oscillations of said thread guide, said sensor comprising a piezofoil disposed in a plane which is parallel to a plane in which said running thread is situated, comprising the steps of:
- (a) supplying a running thread to said textile machine;
- (b) winding said running thread onto a cop;
- (c) passing said running thread through said thread guide;
- (d) sensing oscillations of said thread guide and producing a signal corresponding to said oscillations and the tension in said running thread;
- and
- (e) filtering said signal to obtain elements of said signal corresponding to a basic frequency of operation of said winding means or an harmonic thereof and obtaining from said filtered out frequency a signal corresponding to said tension in said running thread.
A thread tension sensor for sensing tension in a running thread on a textile machine which has a winding element that is operable at least one basic frequency for winding said running thread onto a package, comprising:
- (a) a thread guide for guiding said running thread on said textile machine;
- (b) mounting means for supporting said thread guide on said textile machine to permit said thread guide to oscillate;
- (c) a piezofoil sensing element disposed on said thread guide in a plane which is parallel to a plane through which said running thread passes for generating an electrical signal corresponding to oscillations of said thread guide;
- (d) a tune filter for filtering said electrical signal to produce and transmit an output signal;
- (e) means for tuning said filter in accordance with the prevailing basic frequency of said winding element or an harmonic frequency of said prevailing frequency;
- and
- (f) means for measuring the level of said output signal corresponding to the level of tension in said running thread.
Dependencies are inferred from the claim text.