Abstract: A drawframe is disclosed which has a plurality of sets of draw rolls and includes a provision for the early detection of imperfections in rotating elements in the drawframe. The separation of the pairs of rolls is monitored, and a signal representative of that separation is generated. The resulting signal is then processed so that only intolerable errors remain, and the major harmonic elements of the remaining signal are correlated with the rotational frequencies of the rotating elements of the drafting or drawing apparatus. Establishment of synchronism between significant harmonic components in the signal representative of the separation of the cooperating pair of rolls and the rotational frequency of a rotating element in the apparatus makes it possible to identify any unacceptable mechanical cause of error while the machine is still running.

Abstract: A method and apparatus for continuously measuring the variability of an advancing textile strand is disclosed, and wherein the output signal is useful in diagnosing the source of the variations. The method includes the steps of continuously monitoring at least one selected parameter and applying the resulting signal to each of a plurality of integrating networks each having a different predetermined time constant. The output signal from each of the integrating networks is then applied to a root mean square network to produce an output which closely approximates the standard deviation of the output signal of the associated integrating network. In a further embodiment, the signal from the monitoring device is applied to an integrating network, and the output of the integrating network is applied serially to two root mean square networks. Several embodiments of a transducer are also disclosed which are designed to permit the monitoring of a number of parameters in the moving textile strand.