EP0460442B1 - Device for measuring the thickness and/or the unevenness of slivers - Google Patents

Device for measuring the thickness and/or the unevenness of slivers Download PDF

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Publication number
EP0460442B1
EP0460442B1 EP91108075A EP91108075A EP0460442B1 EP 0460442 B1 EP0460442 B1 EP 0460442B1 EP 91108075 A EP91108075 A EP 91108075A EP 91108075 A EP91108075 A EP 91108075A EP 0460442 B1 EP0460442 B1 EP 0460442B1
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EP
European Patent Office
Prior art keywords
measuring
rollers
leaf spring
sliver
space
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EP91108075A
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German (de)
French (fr)
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EP0460442A1 (en
Inventor
François BAECHLER
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Zellweger Luwa AG
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Zellweger Luwa AG
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    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01H—SPINNING OR TWISTING
    • D01H13/00—Other common constructional features, details or accessories
    • D01H13/14—Warning or safety devices, e.g. automatic fault detectors, stop motions ; Monitoring the entanglement of slivers in drafting arrangements
    • D01H13/22—Warning or safety devices, e.g. automatic fault detectors, stop motions ; Monitoring the entanglement of slivers in drafting arrangements responsive to presence of irregularities in running material

Definitions

  • the invention relates to a device for measuring the thickness and / or the unevenness of fiber slivers, in particular on spinning preparation machines, with a compression member compacting the fiber sliver and with a measuring member for the thickness or the unevenness mechanically scanning the compressed fiber sliver and formed by a leaf spring provided with strain gauges of the sliver.
  • Devices of this type are used for systems for regulating strip weight fluctuations and for quality recording on cards, cards and draw frames and serve to keep the number fluctuations in the yarn so small that they do not interfere in the finished product.
  • the main differences of the known regulating systems lie in the measuring element, for which essentially three types, the so-called active-pneumatic measuring element, the roller measuring system and the fiber pressing system are known. With regard to the first two measuring devices, reference is made to USTER News Bulletin No. 30, June 1982, and for the latter measuring device to US-A-4,864,853.
  • the fiber sliver is scanned by the measuring element formed by a leaf spring in a measuring channel which is provided in a measuring part which is interchangeably arranged on the compression element.
  • This has the advantage that it is no longer necessary to replace the entire compression element in order to adapt to changing band numbers, but only the measuring part.
  • This device has proven itself extremely well in practice, but it has been shown that there are certain limits to the measuring accuracy. It can be assumed that this is directly related to the compression of the sliver, the so-called fill factor, which should be limited by the spatial separation of the compression element on the one hand and the measuring element on the other.
  • the sliver is compressed by a pair of measuring rollers, between which the sliver is pressed together.
  • the compression element and measuring element are not spatially separated, but both functions are performed by the measuring rollers.
  • the two rollers are designed to prevent the sliver from emerging laterally from the nip, overlapping one another, either as step rollers or as so-called groove and key rollers.
  • the groove and key roller measuring element is also known under the name Tongue and Groove.
  • the invention is now intended to provide a device of the type mentioned at the outset which, on the one hand, enables a very high measurement accuracy and, on the other hand, has the lowest possible inertia and can therefore also reliably detect small and short strip weight fluctuations.
  • the compression member is formed by a pair of rollers which delimit two sides of a rectangular measuring space which is closed on three sides and on the fourth side of which the measuring member is arranged.
  • the arrangement of the measuring space between the measuring rolls compacting the fiber sliver has the advantage that the measuring accuracy increases. This means that the sliver is actively driven at the measuring point and this increases the compression of the sliver and thus the filling factor in the measuring room. And since the measuring accuracy increases with increasing fill factor, the measuring accuracy will increase.
  • the measuring element formed by a leaf spring provided with strain gauges makes it possible to measure even very short irregularities, even at high belt speeds.
  • a fiber sliver or a number of up to eight fiber slivers 1 are brought together by a conically converging funnel 2 and fed to a measuring room 3.
  • the measuring space 3 has a rectangular cross section, which is closed on three sides and a measuring cell 4 with a measuring element 5 is arranged on the fourth side.
  • the means delimiting the measuring space 3 contain two rollers 6 and 7, driven in the direction of the arrows shown in FIG. 2, with a smooth or corrugated circumference. Connected to one of these rollers, as shown in the roller 7 on the right in FIGS. 1 and 2, is a guide roller 8 which projects beyond this in diameter and whose shoulder adjacent to the roller 7 laterally delimits the measuring space 3. Of course this can Limitation also take place by other means, for example by a fixed guide plate. Another possibility is shown in FIG. 7.
  • the center distance of the two rollers 6 and 7 is adjustable and thus also the cross-section of the measuring space 3 and the degree of compression of the fiber sliver 1 in the measuring space 3. If this description refers to a sliver, then the sliver in the measuring space 3 is always meant. This is a single sliver, regardless of how many slivers 1 are fed to the hopper 2.
  • the device shown in Figures 1 and 2 is used on a draw frame, then it is arranged at the outlet and / or at the inlet of the drafting system.
  • the cross-section of the fiber sliver 1 passing through the measuring space 3 is scanned by the measuring element 5, as a result of which a corresponding cross-sectional signal is supplied to control electronics.
  • the control electronics process this into a suitable regulating and / or control signal which is fed to a regulating drive for the drafting roller pairs of the drafting system.
  • the sliver will exert a certain force or a certain pressure on the measuring element 5, the size of which is proportional to the thickness of the sliver for a given cross section of the measuring space 3 and thus also reliably indicates non-uniformities of this thickness.
  • the measuring element 5 is designed for measuring the acting pressure and, according to FIGS. 3 and 4, consists of a carrier 9 and a leaf spring 10 carried by the latter, which has a thickening 11 at one end and is fixed to the carrier 9 thereon connected, preferably jammed.
  • the leaf spring 10 rests on corresponding webs of the carrier 9, between which an intermediate space 12 is formed which enables the leaf spring 10 to deflect due to the action of a force F.
  • the leaf spring 10 has in its contact area with the sliver 1 a web 13 which carries a measuring plate 14, which rests on the sliver 1 and receives its pressure F, made of abrasion-resistant material, preferably of hard metal or ceramic.
  • a stop 15 aligned with the web 13 to limit the deflection of the leaf spring 10 in order to prevent the leaf spring 10 from being overstretched or overstressed.
  • strain gauges D1 to D4 are arranged, which are glued or sputtered onto the leaf spring.
  • the sliver 1 running through the measuring space 3 presses against the measuring plate 14 with a force F, whereby the leaf spring 10 is pressed against the intermediate space 12 and thus deformed. This creates the strain gauges D2 and D4 adjacent to measuring plate 14 and strain at strain gauges D1 and D3 adjacent to thicker end 11 of leaf spring 10.
  • FIG. 5 In which the elongation E, which is a function of the force F, is shown over the deflection P of the leaf spring 10.
  • Each strain gauge D1 to D4 has a certain electrical resistance R1 to R4, which resistances are all the same. Since the relative change in resistance when the leaf spring 10 bends is known to be proportional to the strain of the strain gauges, the determination of the strain can be made by measuring this change in resistance. 6 with a Wheatstone bridge circuit, which consists of four branches, which are formed by the ring-shaped interconnected resistors R1 to R4. If you now connect a supply voltage to the connection points between the resistors R1 and R4 on the one hand and R2 to R3 on the other hand U applies, then an output voltage V proportional to the bridge detuning can be tapped at the two remaining connection points, which in turn is proportional to the sum of the strain of the individual strain gauges D1 to D4.
  • the measuring cell 4 has a corresponding connection cable 16 for the electrical connection of the strain gauges D1 to D4 and a hose connection 17.
  • the latter is used to connect a compressed air hose for the automatic cleaning and cooling of the measuring cell 4 and the measuring element 5 in the area of the intermediate space 12 and in the area of the web with the measuring plate 14.
  • the air is supplied to the connection 17 in an impulse in the form of compressed air pulses, the frequency of which and duration is adjustable.
  • FIG. 7 shows a variant of the device shown in FIGS. 1 and 2, in which the side of the measuring space 3 opposite the measuring cell 4 is not closed off by the shoulder of a guide roller or by a guide plate, but by the circumference of a guide roller 18 , which is arranged perpendicular to the two rollers 6, 7, engages between them and is drivingly coupled to the rollers 6, 7 via gears 19.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Textile Engineering (AREA)
  • Preliminary Treatment Of Fibers (AREA)
  • Spinning Or Twisting Of Yarns (AREA)
  • Treatment Of Fiber Materials (AREA)
  • Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)

Abstract

The device comprises a pair of rollers (6, 7) limiting two sides of a rectangular measuring space (3) which is closed on three sides and on the fourth side of which is arranged a measuring member (5) for the thickness or unevenness of the sliver. The third side of the measuring space (3) is closed off by a guide roller (8) or by a guide plate, and the rollers (6, 7) serve for compacting the sliver in the measuring space. The measuring member (5) is formed by a leaf spring equipped with strain gauges. <??>As a result, on the one hand, the measuring accuracy of known devices rises because the sliver is driven actively at the measuring point, thus leading to an increase in the compaction of the sliver and therefore to an increase in the measuring accuracy dependent on the compaction, and, on the other hand, the inertia of the measuring member is very low. <IMAGE>

Description

Die Erfindung betrifft eine Vorrichtung zum Messen der Dicke und/oder der Ungleichmässigkeit von Faserbändern, insbesondere an Spinnereivorbereitungsmaschinen, mit einem das Faserband verdichtenden Verdichtungsorgan und mit einem das verdichtete Faserband mechanisch abtastenden und durch eine mit Dehnungsmessstreifen versehene Blattfeder gebildeten Messorgan für die Dicke beziehungsweise die Ungleichmässigkeit des Faserbandes.The invention relates to a device for measuring the thickness and / or the unevenness of fiber slivers, in particular on spinning preparation machines, with a compression member compacting the fiber sliver and with a measuring member for the thickness or the unevenness mechanically scanning the compressed fiber sliver and formed by a leaf spring provided with strain gauges of the sliver.

Vorrichtungen dieser Art werden für Systeme zur Ausregulierung von Bandgewichtsschwankungen und zur Qualitätserfassung an Karden, Krempeln und Strecken verwendet und dienen dazu, die Nummernschwankungen im Garn so klein zu halten, dass sie in der Fertigware nicht stören. Die Hauptunterschiede der bekannten Reguliersysteme liegen beim Messorgan, für welches im wesentlichen drei Typen, das sogenannte aktiv-pneumatische Messorgan, das Walzenmesssystem und das Faser-Pressungssystem bekannt sind. Bezüglich der ersten beiden Messorgane wird auf das USTER News Bulletin Nr. 30, Juni 1982, verwiesen, bezüglich des letztgenannten Messorgans auf die US-A-4 864 853.Devices of this type are used for systems for regulating strip weight fluctuations and for quality recording on cards, cards and draw frames and serve to keep the number fluctuations in the yarn so small that they do not interfere in the finished product. The main differences of the known regulating systems lie in the measuring element, for which essentially three types, the so-called active-pneumatic measuring element, the roller measuring system and the fiber pressing system are known. With regard to the first two measuring devices, reference is made to USTER News Bulletin No. 30, June 1982, and for the latter measuring device to US-A-4,864,853.

Bei der in der US-A-4 864 853 beschriebenen Vorrichtung der eingangs genannten Art, erfolgt die Abtastung des Faserbandes durch das durch eine Blattfeder gebildete Messorgan in einem Messkanal, welcher in einem am Verdichtungsorgan auswechselbar angeordneten Messteil vorgesehen ist. Dies hat den Vorteil, dass für die Anpassung an wechselnde Bandnummern nicht mehr das gesamte Verdichtungsorgan ausgewechselt zu werden braucht, sondern lediglich der Messteil. Diese Vorrichtung hat sich in der Praxis hervorragend bewährt, es hat sich aber gezeigt, dass der Messgenauigkeit gewisse Grenzen gesetzt sind. Es ist zu vermuten, dass dies unmittelbar mit der Verdichtung des Faserbandes, dem sogenannten Füllfaktor, zusammenhängt, der durch die räumliche Trennung von Verdichtungsorgan einerseits und Messorgan andererseits begrenzt sein dürfte.In the device of the type mentioned at the beginning in US Pat. No. 4,864,853, the fiber sliver is scanned by the measuring element formed by a leaf spring in a measuring channel which is provided in a measuring part which is interchangeably arranged on the compression element. This has the advantage that it is no longer necessary to replace the entire compression element in order to adapt to changing band numbers, but only the measuring part. This device has proven itself extremely well in practice, but it has been shown that there are certain limits to the measuring accuracy. It can be assumed that this is directly related to the compression of the sliver, the so-called fill factor, which should be limited by the spatial separation of the compression element on the one hand and the measuring element on the other.

Beim Walzenmesssystem erfolgt die Verdichtung des Faserbandes durch ein Paar von Messwalzen, zwischen denen das Faserband zusammengepresst wird. Hier sind Verdichtungsorgan und Messorgan nicht räumlich getrennt, sondern beide Funktionen werden durch die Messwalzen wahrgenommen. Die beiden Walzen sind zur Verhinderung eines seitlichen Austretens des Faserbandes aus dem Klemmspalt einander übergreifend ausgebildet, und zwar entweder als Stufenwalzen oder als sogenannte Nut- und Tastenwalzen. Das Nut- und Tastenwalzenmessorgan ist auch unter der Bezeichnung Tongue and Groove bekannt. Mit dem Walzenmesssystem wird zwar eine relativ hohe Verdichtung des Faserbandes erreicht, dafür ist dieses Messsystem aber wegen seines relativ grossen Massenträgheitsmoments sehr träge, so dass es die Vorteile des in der US-A-4 864 853 beschriebenen Faser-Pressungssystems nicht aufzuwiegen vermag.In the roller measuring system, the sliver is compressed by a pair of measuring rollers, between which the sliver is pressed together. Here, the compression element and measuring element are not spatially separated, but both functions are performed by the measuring rollers. The two rollers are designed to prevent the sliver from emerging laterally from the nip, overlapping one another, either as step rollers or as so-called groove and key rollers. The groove and key roller measuring element is also known under the name Tongue and Groove. With the roller measuring system there is a relatively high compression of the sliver achieved, but this measuring system is very slow due to its relatively large moment of inertia, so that it cannot outweigh the advantages of the fiber pressing system described in US Pat. No. 4,864,853.

Durch die Erfindung soll nun eine Vorrichtung der eingangs genannten Art angegeben werden, welche einerseits eine sehr hohe Messgenauigkeit ermöglicht und andererseits eine möglichst geringe Trägheit aufweist und somit auch geringe und kurze Bandgewichtsschwankungen sicher erkennen kann.The invention is now intended to provide a device of the type mentioned at the outset which, on the one hand, enables a very high measurement accuracy and, on the other hand, has the lowest possible inertia and can therefore also reliably detect small and short strip weight fluctuations.

Diese Aufgabe wird erfindungsgemäss dadurch gelöst, dass das Verdichtungsorgan durch ein Paar von Walzen gebildet ist, welche zwei Seiten eines rechteckförmigen, an drei Seiten geschlossenen Messraums begrenzen, an dessen vierter Seite das Messorgan angeordnet ist.According to the invention, this object is achieved in that the compression member is formed by a pair of rollers which delimit two sides of a rectangular measuring space which is closed on three sides and on the fourth side of which the measuring member is arranged.

Die Anordnung des Messraums zwischen den das Faserband verdichtenden Messwalzen hat den Vorteil, dass die Messgenauigkeit steigt. Denn dadurch ist das Faserband an der Messstelle aktiv angetrieben und dies erhöht die Verdichtung des Faserbandes und damit den Füllfaktor im Messraum. Und da die Messgenauigkeit mit steigendem Füllfaktor zunimmt, wird die Messgenauigkeit steigen. Das durch eine mit Dehnungsmessstreifen versehene Blattfeder gebildete Messorgan ermöglicht es, auch sehr kurze Ungleichmässigkeiten zu messen, und zwar auch bei hoher Bandgeschwindigkeit.The arrangement of the measuring space between the measuring rolls compacting the fiber sliver has the advantage that the measuring accuracy increases. This means that the sliver is actively driven at the measuring point and this increases the compression of the sliver and thus the filling factor in the measuring room. And since the measuring accuracy increases with increasing fill factor, the measuring accuracy will increase. The measuring element formed by a leaf spring provided with strain gauges makes it possible to measure even very short irregularities, even at high belt speeds.

Nachfolgend werden Ausführungsbeispiele der Erfindung anhand der Zeichnungen näher erläutert; es zeigen:

Fig. 1
eine schematische Draufsicht auf eine erfindungsgemässe Vorrichtung,
Fig. 2
einen Schnitt nach der Linie II-II von Fig. 1,
Fig. 3
ein Detail von Fig. 2,
Fig. 4
eine Ansicht in Richtung des Pfeiles IV von Fig. 3,
Fig. 5, 6
schematische Darstellungen zur Funktionserläuterung; und
Fig. 7
eine Variante der Vorrichtung von Fig. 1.
Exemplary embodiments of the invention are explained in more detail below with reference to the drawings; show it:
Fig. 1
2 shows a schematic top view of a device according to the invention,
Fig. 2
2 shows a section along the line II-II of FIG. 1,
Fig. 3
a detail of Fig. 2,
Fig. 4
3 shows a view in the direction of arrow IV of FIG. 3,
5, 6
schematic representations to explain the function; and
Fig. 7
a variant of the device of Fig. 1st

Gemäss den Figuren 1 und 2 wird ein Faserband oder eine Anzahl von bis zu acht Faserbändern 1 durch einen konisch zusammenlaufenden Trichter 2 zusammengeführt und einem Messraum 3 zugeführt. Der Messraum 3 weist einen rechteckigen Querschnitt auf, welcher an drei Seiten abgeschlossen und an dessen vierter Seite eine Messzelle 4 mit einem Messorgan 5 angeordnet ist.According to FIGS. 1 and 2, a fiber sliver or a number of up to eight fiber slivers 1 are brought together by a conically converging funnel 2 and fed to a measuring room 3. The measuring space 3 has a rectangular cross section, which is closed on three sides and a measuring cell 4 with a measuring element 5 is arranged on the fourth side.

Die den Messraum 3 begrenzenden Mittel enthalten zwei in Richtung der in Fig. 2 eingezeichneten Pfeile angetriebene Walzen 6 und 7 mit glattem oder geriffeltem Umfang. An die eine dieser Walzen, darstellungsgemäss an die in Fig. 1 und 2 rechte Walze 7, schliesst eine diese im Durchmesser überragende Führungswalze 8 an, deren der Walze 7 benachbarte Schulter den Messraum 3 seitlich begrenzt. Selbstverständlich kann diese Begrenzung auch durch andere Mittel erfolgen, beispielsweise durch eine feste Führungsplatte. Eine andere Möglichkeit ist in Fig. 7 dargestellt.The means delimiting the measuring space 3 contain two rollers 6 and 7, driven in the direction of the arrows shown in FIG. 2, with a smooth or corrugated circumference. Connected to one of these rollers, as shown in the roller 7 on the right in FIGS. 1 and 2, is a guide roller 8 which projects beyond this in diameter and whose shoulder adjacent to the roller 7 laterally delimits the measuring space 3. Of course this can Limitation also take place by other means, for example by a fixed guide plate. Another possibility is shown in FIG. 7.

Der Achsabstand der beiden Walzen 6 und 7 ist einstellbar und damit ebenfalls der Querschnitt des Messraums 3 und der Grad der Verdichtung des Faserbandes 1 im Messraum 3. Wenn in dieser Beschreibung von einem Faserband gesprochen wird, dann ist immer das Faserband im Messraum 3 gemeint. Dieses ist ein einziges Faserband, unabhängig davon, wie viele Faserbänder 1 dem Trichter 2 zugeführt werden.The center distance of the two rollers 6 and 7 is adjustable and thus also the cross-section of the measuring space 3 and the degree of compression of the fiber sliver 1 in the measuring space 3. If this description refers to a sliver, then the sliver in the measuring space 3 is always meant. This is a single sliver, regardless of how many slivers 1 are fed to the hopper 2.

Wenn die in den Figuren 1 und 2 dargestellte Vorrichtung bei einer Strecke verwendet wird, dann ist sie am Auslauf und/oder am Einlauf des Streckwerkes angeordnet. Durch das Messorgan 5 wird der Querschnitt des den Messraum 3 durchlaufenden Faserbandes 1 abgetastet, wodurch an eine Steuerelektronik ein entsprechendes Querschnittssignal geliefert wird. Die Steuerelektronik verarbeitet dieses zu einem geeigneten Regulier- und/oder Steuersignal, welches einem Regelantrieb für die Verzugswalzenpaare des Streckwerks zugeführt wird. Das Faserband wird je nach dem Grad der Verdichtung im Messraum 3 eine bestimmte Kraft oder einen bestimmten Druck auf das Messorgan 5 ausüben, dessen Grösse bei gegebenem Querschnitt des Messraums 3 der Dicke des Faserbandes proportional ist und somit auch Ungleichmässigkeiten dieser Dicke zuverlässig anzeigt.If the device shown in Figures 1 and 2 is used on a draw frame, then it is arranged at the outlet and / or at the inlet of the drafting system. The cross-section of the fiber sliver 1 passing through the measuring space 3 is scanned by the measuring element 5, as a result of which a corresponding cross-sectional signal is supplied to control electronics. The control electronics process this into a suitable regulating and / or control signal which is fed to a regulating drive for the drafting roller pairs of the drafting system. Depending on the degree of compression in the measuring space 3, the sliver will exert a certain force or a certain pressure on the measuring element 5, the size of which is proportional to the thickness of the sliver for a given cross section of the measuring space 3 and thus also reliably indicates non-uniformities of this thickness.

Dementsprechend ist das Messorgan 5 zur Messung des einwirkenden Druckes ausgebildet und besteht gemäss den Fig. 3 und 4 aus einem Träger 9 und aus einer von diesem getragenen Blattfeder 10, welche an ihrem einen Ende eine Verdickung 11 aufweist und an dieser mit dem Träger 9 fest verbunden, vorzugsweise verklemmt ist. Die Blattfeder 10 liegt auf entsprechenden Stegen des Trägers 9 auf, zwischen denen ein die Durchbiegung der Blattfeder 10 aufgrund der Wirkung einer Kraft F ermöglichender Zwischenraum 12 gebildet ist.Accordingly, the measuring element 5 is designed for measuring the acting pressure and, according to FIGS. 3 and 4, consists of a carrier 9 and a leaf spring 10 carried by the latter, which has a thickening 11 at one end and is fixed to the carrier 9 thereon connected, preferably jammed. The leaf spring 10 rests on corresponding webs of the carrier 9, between which an intermediate space 12 is formed which enables the leaf spring 10 to deflect due to the action of a force F.

Die Blattfeder 10 weist in ihrem Kontaktbereich mit dem Faserband 1 einen Steg 13 auf, welcher ein am Faserband 1 anliegendes und dessen Druck F aufnehmendes Messplättchen 14 aus abriebfestem Material, vorzugsweise aus Hartmetall oder Keramik trägt. Im Zwischenraum 12 ist ein mit dem Steg 13 fluchtender Anschlag 15 zur Begrenzung der Auslenkung der Blattfeder 10 angeordnet, um eine Ueberdehnung oder Ueberbeanspruchung der Blattfeder 10 zu verhindern.The leaf spring 10 has in its contact area with the sliver 1 a web 13 which carries a measuring plate 14, which rests on the sliver 1 and receives its pressure F, made of abrasion-resistant material, preferably of hard metal or ceramic. Arranged in the intermediate space 12 is a stop 15 aligned with the web 13 to limit the deflection of the leaf spring 10 in order to prevent the leaf spring 10 from being overstretched or overstressed.

An der dem Zwischenraum 12 zugewandten Seite der Blattfeder 10 sind mindestens zwei, darstellungsgemäss vier, Dehnungsmessstreifen D1 bis D4 angeordnet, welche auf die Blattfeder geklebt oder aufgesputtet sind. Das durch den Messraum 3 laufende Faserband 1 drückt mit einer Kraft F gegen das Messplättchen 14, wodurch die Blattfeder 10 gegen den Zwischenraum 12 gedrückt und somit deformiert wird. Dabei entsteht an den dem Messplättchen 14 benachbarten Dehnungsmessstreifen D2 und D4 eine Dehnung und an den dem dickeren Ende 11 der Blattfeder 10 benachbarten Dehnungsmessstreifen D1 und D3 eine Stauchung.On the side of the leaf spring 10 facing the intermediate space 12, at least two, as shown four, strain gauges D1 to D4 are arranged, which are glued or sputtered onto the leaf spring. The sliver 1 running through the measuring space 3 presses against the measuring plate 14 with a force F, whereby the leaf spring 10 is pressed against the intermediate space 12 and thus deformed. This creates the strain gauges D2 and D4 adjacent to measuring plate 14 and strain at strain gauges D1 and D3 adjacent to thicker end 11 of leaf spring 10.

Dies ist in Fig. 5 gezeigt, in welcher die Dehnung E, welche eine Funktion der Kraft F ist, über der Auslenkung P der Blattfeder 10 eingezeichnet ist. Mit zunehmender Kraft F und damit wachsender Auslenkung P der Blattfeder 10 nimmt einerseits bei den Dehnungmessstreifen D2 und D4 die Dehnung und andererseits bei den Dehnungsmessstreifen D1 und D3 die Stauchung (= negative Dehnung) ständig zu, und zwar bis zu einem Maximalwert von +Em beziehungsweise -Em, der dann vorliegt, wenn die Blattfeder 10 bis zum Anschlag 15 (Fig. 3) durchgebogen ist.This is shown in FIG. 5, in which the elongation E, which is a function of the force F, is shown over the deflection P of the leaf spring 10. With increasing force F and thus increasing deflection P of the leaf spring 10, on the one hand the strain increases with the strain gauges D2 and D4 and on the other hand the compression (= negative strain) increases with the strain gauges D1 and D3, namely up to a maximum value of + Em or -Em, which is present when the leaf spring 10 is bent up to the stop 15 (Fig. 3).

Jeder Dehnungmessstreifen D1 bis D4 hat einen bestimmten elektrischen Widerstand R1 bis R4, wobei diese Widerstände alle gleich sind. Da die relative Widerstandsänderung bei Durchbiegung der Blattfeder 10 bekanntlich proportional zur Dehnung der Dehnungsmessstreifen ist, kann die Bestimmung der Dehnung durch eine Messung dieser Widerstandsänderung erfolgen. Dies erfolgt gemäss Fig. 6 mit einer Wheatstoneschen Brückenschaltung, welche aus vier Zweigen besteht, die von den ringförmig zusammengeschalteten Widerständen R1 bis R4 gebildet werden. Wenn man nun an die Anschlusspunkte zwischen den Widerständen R1 und R4 einerseits und R2 bis R3 anderserseits eine Speisespannung U anlegt, dann kann man an den beiden übriger Anschlusspunkten eine zur Brückenverstimmung proportionale Ausgangsspannung V abgreifen, welche ihrerseits der Summe der Dehnung der einzelnen Dehnungsmessstreifen D1 bis D4 proportional ist.Each strain gauge D1 to D4 has a certain electrical resistance R1 to R4, which resistances are all the same. Since the relative change in resistance when the leaf spring 10 bends is known to be proportional to the strain of the strain gauges, the determination of the strain can be made by measuring this change in resistance. 6 with a Wheatstone bridge circuit, which consists of four branches, which are formed by the ring-shaped interconnected resistors R1 to R4. If you now connect a supply voltage to the connection points between the resistors R1 and R4 on the one hand and R2 to R3 on the other hand U applies, then an output voltage V proportional to the bridge detuning can be tapped at the two remaining connection points, which in turn is proportional to the sum of the strain of the individual strain gauges D1 to D4.

Gemäss Fig. 2 weist die Messzelle 4 ein entsprechendes Anschlusskabel 16 für den elektrischen Anschluss der Dehnungsmessstreifen D1 bis D4 sowie einen Schlauchanschluss 17 auf. Letzterer dient zum Anschluss eines Druckluftschlauchs für die automatische Reinigung und Kühlung der Messzelle 4 und des Messorgans 5 im Bereich des Zwischenraums 12 und im Bereich des Stegs mit dem Messplättchen 14. Dabei wird die Luft dem Anschluss 17 impulsartig in Form von Druckluftstössen zugeführt, deren Frequenz und Dauer einstellbar ist.2, the measuring cell 4 has a corresponding connection cable 16 for the electrical connection of the strain gauges D1 to D4 and a hose connection 17. The latter is used to connect a compressed air hose for the automatic cleaning and cooling of the measuring cell 4 and the measuring element 5 in the area of the intermediate space 12 and in the area of the web with the measuring plate 14. The air is supplied to the connection 17 in an impulse in the form of compressed air pulses, the frequency of which and duration is adjustable.

Die Anpassung der dargestellten Messvorrichtung an wechselnde Banddicken ist äusserst einfach und kann auf verschiedene Art erfolgen:

  • Verwendung von Walzen 6, 7 mit verschiedenen Durchmessern,
  • Verwendung von Walzen 6, 7 mit verschiedenen Breiten,
  • Verwendung von Walzen 6, 7 mit verschiedenen Durchmessern und Breiten,
  • Aenderung des Achsabstandes der Walzen 6, 7.
The adaptation of the measuring device shown to changing strip thicknesses is extremely simple and can be done in different ways:
  • Use of rollers 6, 7 with different diameters,
  • Use of rollers 6, 7 with different widths,
  • Use of rollers 6, 7 with different diameters and widths,
  • Changing the center distance of the rollers 6, 7.

In Fig. 7 ist eine Variante der in den Fig. 1 und 2 dargestellten Vorrichtung dargestellt, bei welcher die der Messzelle 4 gegenüberliegende Seite des Messraums 3 nicht durch die Schulter einer Führungswalze oder durch eine Führungsplatte abgeschlossen ist, sondern durch den Umfang einer Führungswalze 18, welche senkrecht zu den beiden Walzen 6, 7 angeordnet ist, zwischen diese eingreift und über Zahnräder 19 mit den Walzen 6, 7 antriebsmässig gekuppelt ist.FIG. 7 shows a variant of the device shown in FIGS. 1 and 2, in which the side of the measuring space 3 opposite the measuring cell 4 is not closed off by the shoulder of a guide roller or by a guide plate, but by the circumference of a guide roller 18 , which is arranged perpendicular to the two rollers 6, 7, engages between them and is drivingly coupled to the rollers 6, 7 via gears 19.

Claims (13)

  1. Device for measuring the thickness and/or the unevenness of slivers, in particular on preparatory spinning machines, having a compaction element compacting the sliver (1) and a measuring element (5) for the thickness or non-uniformity of the sliver (1), which measuring element (5) mechanically scans the compacted sliver (1) and is formed by a leaf spring (10) provided with strain gauges (D1-D4), characterised in that the compaction element is formed by a pair of rollers (6, 7) which limit two sides of a rectangular measuring space (3) which is closed on three sides and on whose fourth side the measuring element (5) is arranged.
  2. Device according to Claim 1, characterised in that the third side of the measuring space (3) is closed off by a guide roller (8, 18).
  3. Device according to Claim 2, characterised in that the rollers (6, 7) are driven, and in that the guide roller (8) is arranged on the drive spindle of one of the rollers and directly next to this roller and has a shoulder covering the third side of the measuring space (3).
  4. Device according to Claim 2, characterised in that the rollers (6, 7) are driven, and in that the guide roller (18) is arranged perpendicularly to the rollers and is coupled to the latter as a drive and, with its periphery, engages between the rollers on the third side of the measuring space (3).
  5. Device according to Claim 1, characterised in that the third side of the measuring space (3) is closed off by a guide plate.
  6. Device according to one of Claims 1, 2, 3 or 5, characterised in that the distance between the axes of the rollers (6, 7) can be adjusted for adaptation to varying thicknesses of the sliver (1).
  7. Device according to Claim 6, characterised in that the leaf spring (10) is of elongated design and is fastened at one end (11) to a support (9).
  8. Device according to Claim 7, characterised in that the leaf spring (10) is oriented in the direction of the straight connecting line between the axes of the two rollers (6, 7).
  9. Device according to Claim 8, characterised in that the leaf spring (10), in its centre part, is provided with a web (13) which carries a measuring lamina (14) provided for contacting the sliver (1).
  10. Device according to Claim 9, characterised in that at least one pair of strain gauges (D1-D4) is provided, of which one is arranged adjacent to the said web (13) and the other is arranged adjacent to the clamping location (11) of the leaf spring (10).
  11. Device according to Claim 10, characterised in that the strain gauges (D1-D4) are arranged on the side of the leaf spring (10) remote from the web (13) having the measuring lamina (14).
  12. Device according to Claim 11, characterised in that, at the side of the leaf spring (10) carrying the strain gauges (D1-D4), an intermediate space (12) is formed between this leaf spring (10) and its support (9), into which intermediate space (12) a compressed-air line (17) leads for the supply of compressed air for cooling and/or cleaning purposes.
  13. Device according to Claim 12, characterised in that the compressed air is supplied in pulses, the frequency and/or duration of the air pulses being adjustable.
EP91108075A 1990-05-30 1991-05-18 Device for measuring the thickness and/or the unevenness of slivers Expired - Lifetime EP0460442B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH1832/90 1990-05-30
CH1832/90A CH681310A5 (en) 1990-05-30 1990-05-30

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EP0460442A1 EP0460442A1 (en) 1991-12-11
EP0460442B1 true EP0460442B1 (en) 1995-01-18

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US (1) US5123280A (en)
EP (1) EP0460442B1 (en)
JP (1) JP2943087B2 (en)
AT (1) ATE117383T1 (en)
CH (1) CH681310A5 (en)
DE (1) DE59104291D1 (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4142038C5 (en) * 1991-12-19 2012-03-15 Rieter Ingolstadt Gmbh Apparatus for processing a plurality of slivers
DE4404326A1 (en) † 1993-04-02 1994-10-06 Truetzschler Gmbh & Co Kg Device for measuring the thickness of a sliver with a sliver guide for guiding the slivers at the drafting device inlet
DE19500189B4 (en) * 1995-01-05 2006-09-14 Rieter Ingolstadt Spinnereimaschinenbau Ag Method for pressing a feeler on a fiber structure in a tape guide and device for their production
US5626512A (en) * 1995-05-04 1997-05-06 Minnesota Mining And Manufacturing Company Scouring articles and process for the manufacture of same
IT1302166B1 (en) * 1997-09-17 2000-07-31 Truetzschler & Co DEVICE ON A STRIRATOIO FOR THE MEASUREMENT OF A FIBRECOMPOSITE TAPE MADE OF FIBER TAPES
US10222278B2 (en) 2016-02-25 2019-03-05 Massachusetts Institute Of Technology Directional force sensing element and system
CN106087151A (en) * 2016-08-19 2016-11-09 安徽华茂纺织股份有限公司 Reel cage arc pawl adjusts specific purpose tool

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2680266A (en) * 1948-07-26 1954-06-08 John G Kershaw Sliver condensing
US3822590A (en) * 1972-05-01 1974-07-09 Maremont Corp Textile sliver unevenness detecting
CH553981A (en) * 1972-05-10 1974-09-13 Rieter Ag Maschf DEVICE FOR MEASURING DENSITY FLUCTUATIONS OF A FIBER SLIB IN SPINNING MACHINES.
DE3569760D1 (en) * 1985-02-15 1989-06-01 Rieter Ag Maschf Apparatus for the continuous mass control of a fibre ribbon
CH668833A5 (en) * 1986-01-16 1989-01-31 Zellweger Uster Ag DEVICE FOR MEASURING AND / OR COMPARISONING THE TAPE THICKNESS OF FIBER TAPES.
DE3913548C2 (en) * 1989-04-25 2000-08-31 Truetzschler Gmbh & Co Kg Device for measuring the sliver thickness and the unevenness of a sliver on spinning preparation machines

Also Published As

Publication number Publication date
US5123280A (en) 1992-06-23
EP0460442A1 (en) 1991-12-11
ATE117383T1 (en) 1995-02-15
JP2943087B2 (en) 1999-08-30
DE59104291D1 (en) 1995-03-02
JPH04228673A (en) 1992-08-18
CH681310A5 (en) 1993-02-26

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