Zellweger Uster, Inc.

Werner Grunder

Erwin Murbach

Ernst Loch

Francois Baechler

Apparatus for measuring the thickness of fibre slivers

Method and apparatus for controlling fluctuations in sliver weight on

A device for obtaining a control signal corresponding to the density of the fibre covering lying on a fibre carrying element such as the cylinder, the licker-in, the take-off roller, or the doffer of a card. The device includes a holder which extends over the width of the fibre carrying element to span the width of the fibre covering on the fibre carrying element. This holder contains means responsive to the density of the fibre covering which produces electric output signals corresponding to the density of the fibre covering.

Device for obtaining a control signal corresponding to the density of

A method of and apparatus for regulating out variations in the sliver weight on processing machines such as cards, carding engines, draw frames and the like wherein a first measuring device measures either the absolute cross-section or the relative variations of cross-section relative to a predetermined fixed desired value of a fibre sliver issuing from the machine. The first measuring device forms a corresponding first test signal. An additional measuring device is arranged at a point upstream of the first measuring device with respect to the direction of travel of the fibre material. The additional measuring device produces a second test signal corresponding to the relative variations in the cross-section of the fibre material relative to an average value for these variations formed over a predetermined period. The first and second test signals are used for controlling at least one regulating device which controls the cross-section of the fibre sliver.

Method and apparatus for regulating out variations in the sliver weight

In the continuous measurement and control of deviations in cross-section of slivers with constant relative sensitivity which is independent of the adjusted set value with respect to this set value, the sliver is guided between a grooved roller and a feeler roller which contact each other in the absence of the sliver between the grooved roller and the feeler roller. The changes in the position of the feeler roller are converted into rotational movements of a lever shaft and thus into changes of direction of a measuring tab. The measuring tab is arranged eccentrically on the lever shaft. A sensor is movable by means of a lead spindle which is perpendicular to the lever shaft and lies in a plane determined by the lever shaft and by the axis of the feeler roller in the absence of sliver between the rollers. This sensor preferably has a magneto-resistor. The changes in direction of the measuring tab are, therefore, transformed into fault signals of the magneto-resistor, the fault signals being used to control the thickness of the sliver.

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Monchaltorf, Switzerland

Werner Grunder