Abstract: The invention relates to roller unit consisting of an inductively heated roller, a drive motor, an inductor and a frequency converter. According to the invention not only the converter but also the temperature regulator for the induction heater and monitoring devices for the roller, heater and/or motor are integrated into the roller unit. The power electronics and the regulator are mounted on a common cooling unit which is cooled by a coolant which at the same time also cools the motor, the bearings and the inductor.

Abstract: For monitoring the appropriate operation of a plurality of control loops having the same setpoint, the control ratio is measured at each controller, is normalized and an alarm signal is generated if said normalized control ratio exceeds a predetermined alarm band.

Abstract: In an apparatus for contact-free transmission of condition responsive electrical signals from a rotating machine part to a stationary machine part a single rotational transformer having a stationary primary winding and a rotating secondary winding is used for (a) transmitting power supply signals from a stationary evaluation circuit to a rotating transducer, (b) transmitting condition responsive measuring signals from the transducer to the evaluation circuit, and (c) transmitting synchronizing signals between the transducer and the evaluation circuit.

Abstract: The properties synchronous motors are provided to an asynchronous motor fed with the aid of a digital speed control via a static converter. For this purpose, a signal proportional to an integral of the rotation-speed deviation, and a signal corresponding to the rotation-speed set-point value, are multiplied with each other and therefrom is obtained the control-pulse sequence for the converter. From an input sequence corresponding to the measured rotation speed, a signal corresponding to the period duration of the rotation-speed measurement-device frequency is obtained, and this signal is divided by a value corresponding to the rotation-speed set-point value. The period-duration signal referring to the rotation-speed set-point value thus obtained is switched opposite to the control-deviation signal, before the control-deviation signal is fed to the multiplier.

Abstract: An apparatus for the heat treatment of synthetic yarn is provided where synthetic yarn is provided by a synthetic yarn source and is fed via rollers to a first heating surface and then via a heating pin to a second heating surface and from there via rollers to a warping beam. A speed control of the yarn and a breakage control of the yarn can be provided. Depending on the resulting control signals the heating pin and concurrently therewith a cam wheel can be rotated, where the cam wheel and the heating pin are joined by an endless cable. The cam wheel is connected to the two heating surfaces via bars which allow to move and remove the heating surfaces from the path of the yarn. Heat transfer can be provided from the output rollers to the input rollers.

Abstract: For heating synthetic yarns and fibers an elongated vessel filled with saturated steam is provided through which the yarn is continuously drawn. The steam condensates on the yarn and transfers its condensation heat to the yarn. For sealing the vessel (3) at the inlet (2) and the outlet (4), several apertures (6-9, 13-16) are provided in a pair of tubes (5,12) surrounding the traveling path of the yarn (1). The space between the first aperture and the opening adjacent the steam vessel (3) is connected to a blocking liquid supply pipe (30) and the space between the last aperture (9,16) and the inlet hole (10) and the outlet hole (17), respectively, for the yarn is connected to a blocking liquid return pipe (31). The blocking liquid supply pipe is kept under a pressure which is somewhat higher than the pressure within the steam vessel (3).