Abstract: In a fiber tuft feeding apparatus the throughgoing tuft quantities are sensed, signals representing such quantities are emitted and in response to the signals, a tuft quantity metering member, such as a feeding roll is controlled by analog setting signals.

Abstract: An electronic pressure switch composed of a flexible diaphragm carrying a conductive plate and two axially displaceable electronic proximity switch members each disposed at a respective opposite side of the diaphragm, each switch member being arranged to be actuated upon movement of the plate to within a predetermined distance therefrom, under the action of a pressure medium acting on one side of the diaphragm.

Abstract: An apparatus for sensing the density variation of a sliver, includes a sliver funnel through which the sliver passes and which has an intake portion, a discharge portion and a chamber formed as an enlarged part of the discharge portion. The chamber is, through a lateral opening, in communication with a source of pressurized air and a pressure sensing device. The pressure sensing device receives pneumatic signals as a function of the variation of pressure in the chamber dependent upon the density of the sliver portion momentarily present in the chamber. The sliver funnel is arranged at an output of a carding machine for receiving a web discharged thereby and for combining the web into a sliver passing through the chamber. The pressure sensing device comprises a pressure-responsive precision sensor which includes an arrangement for converting the pneumatic signals into digital signals.

Abstract: An apparatus for making a uniform, continuous sliver has a sliver sensor for continuously sensing the throughput quantity of the sliver and generating a continuous main regulating signal x as a function of the throughput quantity and a first regulator connected to the sliver sensor for receiving the signal x and generating a reference signal w.sub.h as a function of the signal x. The apparatus further has a tuft column sensor connected to a tuft shaft of a card for sensing a variable of the tuft column advancing in the tuft shaft. The tuft column sensor has a signal generator for emitting an auxiliary regulating signal x.sub.h as a function of the sensed variable of the tuft column and a desired value setter which receives the signal w.sub.h and varies the signal x.sub.h as a function of the signal w.sub.h. Further, the apparatus has a tuft column altering arrangement including a second, auxiliary regulator which receives the signal x.sub.