Patent Publication Number: US-7908714-B2

Title: Apparatus at a spinning preparation machine for the purpose of monitoring

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority from German Patent Application No. 10 2005 050 904.5 dated Oct. 21, 2005, the entire disclosure of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     The invention relates to an apparatus at a spinning preparation machine, especially at a flat card, roller card or the like, in which a clothed, rapidly rotating roller lies opposite to at least one clothed and/or non-clothed component and the spacing between the components lying opposite to one another is changeable. 
     In flat cards, crashes occur that are caused by incorrect settings or incorrect machine operation. The repair costs for such crashes are considerable. The result of even any slight contact between a stationary component and, for example, a carding cylinder, is destructive because, in the event of contact, the roller clothing strongly takes hold of the components because of its aggressive tooth setting and, when contact is identified, for example by an operator, the rollers run on for at least five minutes until they come to a standstill. During that time the damage becomes ever greater. 
     The effective spacing of the tips of a clothing from a machine element lying opposite to the clothing is called the carding nip. The last-mentioned element may also have a clothing but could, instead of that, be formed by a segment of a circuit having a conductive face. The carding nip determines the carding quality. The size (width) of the carding nip is an important machine parameter that shapes both the technology (fibre processing) and the running behaviour of the machine. The carding nip is set as narrow as possible (it is measured in tenths of a millimeter) without the risk of a “collision” of the working elements being incurred. In order to ensure uniform processing of the fibres, the nip needs to be as identical as possible over the whole of the working width of the machine. 
     The carding nip is affected especially by the machine settings on the one hand and by the condition of the clothing on the other hand. The most important carding nip of the revolving card top flat card is located in the main carding zone, that is to say between the cylinder and the revolving card top assembly. At least one clothing that limits the working spacing of the carding zone as a whole is in motion, usually both. In order to increase the production rate of the flat card, it is sought to select an operating rotational speed, or an operating speed of the moving parts, that is as high as the fibre processing technology allows. The working spacing changes in dependence on the operating conditions. The change occurs in the radial direction (starting from the rotational axis) of the cylinder. 
     During carding, increasingly large amounts of fibre material are processed per unit of time, which requires higher working component speeds and higher installed outputs. The increasing throughput of fibre material (production rate), even when the working surface area remains constant, results in increased generation of heat as a result of the mechanical work. At the same time, however, the technological carding result (sliver uniformity, degree of cleaning, nep reduction etc.) is constantly being improved, which requires a greater number of effective surfaces in carding engagement and narrower settings of those effective surfaces with respect to the cylinder (tambour). The proportion of synthetic fibres being processed, which—compared with cotton—generate more heat as a result of friction when in contact with the effective surfaces of the machine, is continually increasing. The working components of high-performance flat cards are nowadays totally enclosed on all sides in order to conform to the high safety standards, to prevent the emission of particles into the spinning room environment and to minimise the need for servicing of the machines. Grids or even open, material-guiding surfaces allowing exchange of air are a thing of the past. The said circumstances markedly increase the input of heat into the machine, while the discharge of heat by means of convection is markedly reduced. The resulting more intense heating of high-performance flat cards leads to greater thermoelastic deformation which, on account of the non-uniform distribution of the temperature field, affects the set spacings of the effective surfaces: the gaps between cylinder and card top, doffer, fixed card flats and take-off stations with blades are reduced. In an extreme case, the set gap between the effective surfaces can be completely consumed by thermal expansion, so that components moving relative to one another collide, resulting in considerable damage to the affected high-performance flat card. Accordingly, particularly the generation of heat in the working region of the flat card can lead to different degrees of thermal expansion when the temperature differences between the components are too great. 
     In order to reduce or avoid the risk of collisions, the carding nip between clothings lying opposite to one another is in practice set relatively wide, that is to say a certain safety spacing exists, but a large carding nip results in undesired nep formation in the card sliver. On the other hand, an optimum, especially narrow, dimension, by means of which the nep occurrence in the card sliver is appreciably reduced, is desirable. 
     It is an aim of the invention to provide an apparatus of the type described at the outset that avoids or mitigates the mentioned disadvantages and, especially, when opposite-lying components draw near to one another, avoids contact between those components in a simple manner. 
     SUMMARY OF THE INVENTION 
     The invention provides an apparatus at a spinning preparation machine for the purpose of monitoring the spacing between a clothed, rapidly rotating roller and at least one clothed and/or non-clothed component opposed to said roller, the spacing between the roller and said component(s) lying opposite thereto being changeable, comprising a sensor which is arranged to give rise to a response in the event of contact between the roller and a said component. 
     In an especially preferred embodiment there is, arranged opposite to the clothing of the roller, at a second spacing, a sensor which is a part of an electrical circuit, wherein contact between the clothing and the sensor causes interruption of the circuit. 
     According to the invention, the sensor is set closer to the roller than is the component lying opposite to the roller. In the event of contact with the rapidly rotating roller, the sensor is destroyed. When that happens, electrical transmission is cut and consequently electric current, for example to a control system, display or alarm device, switching device or the like, is interrupted. The sensor is constantly energised. If, for example, a cable, which runs parallel in the sensor to the roller, is destroyed by contact with a clothing, the circuit is interrupted and a signal is delivered. For the crash sensor, that constitutes a destructive measurement. 
     Advantageously, starting from the roller, the second spacing to the sensor is smaller than the spacing to the component. Advantageously, the sensor is immobile. Advantageously, the sensor is an electrically conductive component of the electric circuit. Advantageously, two lines are connected to the electrically conducting sensor. Advantageously, at least one electrically conductive element, for example wire, is integrated into the sensor. Advantageously, the sensor consists of plastics or the like in which an electrical conductor is integrated. Advantageously, the current line is passed through the sensor body. Advantageously, an electrically conducting wire (current line) is embedded into the sensor body. Advantageously, the sensor body has a conductive coating, a conductive cover or the like. Advantageously, the sensor is arranged in the vicinity of the roller. Advantageously, the sensor generates an electric signal change directly from any contact between the component and the roller. Advantageously, the signal change is fed to a control system. Advantageously, the sensor is mounted at a carding machine, for example a flat card. The sensor may be fastened to a mounted component. The sensor may be fastened to a working element. The sensor may be fastened to an immobile side panel. The sensor may be fastened to an extension bend or flexible bend of a cylinder. Advantageously, the sensor is fastened to the side of a mounted component that faces a roller. Advantageously, an electrically conducting cable is guided into a body, for example a cylindrical body or the like, parallel to the surface. Advantageously, the cable lies directly below the body surface. Advantageously, in the event of contact of the sensor with a roller clothing, the cable is destroyed at the surface by the clothing and thus the electric current is interrupted. Advantageously, the sensor is fastened into a mounted component at the roller side in such a manner that the cable parallel to the sensor surface is aligned close to the roller and parallel thereto. Advantageously, the sensor is so fastened in the mounted component that the spacing between roller and sensor is smaller than or equal to the spacing between roller and mounted component. Advantageously, there is a plurality of sensors attached to a mounted component. Advantageously, each group of mounted components is equipped at least with one or more sensors. Advantageously, each mounted component, which is set as close as possible to the roller, is equipped with a sensor. Advantageously, the signals of the sensors are evaluated by the control system. Advantageously, the sensor is connected to an alarm device. Advantageously, the sensor is connected to a display device. Advantageously, the sensor is connected to a cut-off device for the carding machine. 
     The invention also provides an apparatus at a spinning preparation machine, especially a flat card, roller card or the like, for the purpose of monitoring, in which a clothed, rapidly rotating roller lies opposite to at least one clothed and/or non-clothed component and the spacing between the components lying opposite to one another is changeable, in which, in order to monitor the spacing between the components lying opposite to one another, there is arranged opposite to the clothing of the roller, at a spacing, a sensor which is an integral component of an electric current line, wherein contact between clothing and sensor or current line interrupts the circuit. 
     Moreover, the invention provides an apparatus at a spinning preparation machine, especially a flat card, roller card or the like, for the purpose of monitoring, in which a clothed, rapidly rotating roller lies opposite to at least one clothed and/or non-clothed component and the spacing between the components lying opposite to one another is changeable, in which, in order to monitor the spacing between the components lying opposite to one another there is provided a sensor which, in the event of contact between the components lying opposite to one another, delivers an electric signal. 
     Advantageously, a piezo-ceramic sensor is used. Advantageously, the piezo-ceramic sensor is a sensor for structure-born noise. Advantageously, the piezo-ceramic sensor is fastened to a clothed carding element. Advantageously, the piezo-ceramic sensor is fastened to a flexible bend. Advantageously, the piezo-ceramic sensor is fastened to an extension bend. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagrammatic side view, in section, of a flat card in which there may be included apparatus according to the invention, 
         FIG. 2  is a partial view in section through the flat card according to  FIG. 1  having an apparatus according to the invention, 
         FIG. 3  shows an embodiment in which the sensor is an integral component of a current line, 
         FIG. 4  shows an embodiment with a sensor at a holding element for a separator blade, 
         FIG. 5  is a side view of a part of a flat card with an immobile side panel, showing a portion of the machine frame and of the revolving card top of the flat card with a sensor both at an extension bend and at a side panel and 
         FIG. 6  shows a sensor at an exhaust hood of a flat card. 
     
    
    
     DETAILED DESCRIPTION OF CERTAIN PREFERRED EMBODIMENTS 
       FIG. 1  shows a flat card, for example a TC 03 (Trademark) flat card made by Trützschler GmbH &amp; Co. KG of Mönchengladbach, Germany, having a feed roller  1 , feed table  2 , lickers-in  3   a ,  3   b ,  3   c , cylinder  4 , doffer  5 , stripper roller  6 , nip rollers  7 ,  8 , web-guiding element  9 , web funnel  10 , delivery rollers  11 ,  12 , revolving card top  13  having card top guide rollers  13   a ,  13   b  and flats  14 , can  15  and can coiler  16 . The directions of rotation of the rollers are indicated by curved arrows. Reference letter M denotes the centre (axis) of the cylinder  4 . Reference numeral  4   a  denotes the clothing and reference numeral  4   b  the direction of rotation of the cylinder  4 . Reference letter B denotes the direction of rotation of the revolving card top  13  in the carding position and reference letter C denotes the return transport direction of the flats  14 ; reference numerals  27 ′,  27 ″ denote fixed carding elements and reference numeral  26  denotes a cover underneath the cylinder  4 . The arrow A indicates the working direction. 
       FIG. 2  shows a portion of the cylinder  4  with a cylindrical surface  4   f  of the casing  4   e  and with cylinder ends  4   c ,  4   d  (radial support elements). The surface  4   f  is provided with a clothing  4   a  which, in this example, is provided in the form of wire with saw teeth. The saw-tooth wire is mounted on the cylinder  4 , that is to say it is wound between side flanges (not shown) in closely juxtaposed windings to form a cylindrical working surface equipped with tips. Fibres are to be processed as uniformly as possible on the working surface (clothing). The carding is accomplished between the opposite-lying clothings  18  and  4   a . It is appreciably affected by the position of one clothing in relation to the other and by the clothing spacing a between the tips of the teeth of the two clothings  18  and  4   a . The working width of the cylinder  4  forms the basis for all other working elements of the flat card, especially for the revolving card top  13  or fixed card flats  27 ′,  27 ″ ( FIG. 1 ), which, together with the cylinder  4 , card the fibres uniformly over the whole of the working width. In order to be able to achieve uniform carding over the whole of the working width, the settings of the working elements (including additional elements) need to be maintained over that working width. The cylinder  4  itself may, however, become deformed as a result of the clothing wire&#39;s being drawn on, as a result of centrifugal force or as a result of heating caused by the carding process. The shaft journals  23   a ,  23   b  of the cylinder  4  are mounted in bearings  25   a ,  25   b , which are mounted on the immobile machine frame  24   a ,  24   b . The diameter, for example 1250 mm, of the cylindrical surface  4   f , that is to say twice the radius r 1 , is an important dimension of the machine. The side panels  19   a ,  19   b  are fastened onto the two machine frames  24   a  and  24   b , respectively. Fastened to the side panels  19   a ,  19   b  are the flexible bends  17   a  and  17   b , respectively. The circumferential speed of the cylinder  4  is, for example, 35 m/sec. Reference numeral  33  denotes a sensor which is associated with a revolving card flat  14 , the spacing b from the cylinder clothing  4   a  to the end faces  33   a  of the sensor  33  being smaller than the spacing to the card top clothing  18  (see  FIG. 3 ). 
     In the embodiment of  FIG. 3 , the sensor  33  consists of a basic body  33   b , for example of plastics material or the like, in which there is integrated an electrical conductor  34 , for example a metal wire, a cable or the like. In the region denoted by reference numeral  34   a , the wire  34  is arranged parallel to the end face  33   a  and to the clothing  4   a  (see  FIG. 2 ). The wire  34  is permanently connected to a voltage supply  35 . There is normal earth contact between the metal component  27  and the metal roller  4  by way of the line  36 . Current flows continuously between the contacts  35   a  and  35   b . If, during operation, the cable  34 , which runs parallel (see  34   a ) in the sensor  33  to the roller  4 , is destroyed by contact with the high-speed clothing  4   a , the circuit is interrupted and a signal is delivered in a display device  37  and/or a switching procedure is triggered in a switching device (not shown), for example a switching-off device. 
     In the embodiment of  FIG. 4 , the sensor  33  is mounted at a holding element  38  (blade carrying rail) for a separator blade  31 , that is, it is mounted at a non-clothed machine element. Reference numeral  32  denotes an immobile retainer frame. 
     The sensors  33  deliver an electric signal in the event of contact between the sensor  33  and a high-speed roller  4 , for example the cylinder clothing  4   a , that is, in the event of contact of the sensor  33  with a component. The purpose of that is to ascertain undesired contact between a component and a high-speed roller. 
     In the embodiment of  FIG. 5 , between lickers-in  3  and card top guide roller  13   a  there are three immobile fixed carding elements  27   a ,  27   b    27   c  and non-clothed cylinder casing elements  28   a ,  28   b ,  28   c . The fixed carding elements  27  have a clothing that lies opposite to the cylinder clothing  4   a . The fixed carding elements  27   a  to  27   c  are attached by way of screws and the cover elements  28   a  to  28   c  are attached by way of screws (not shown) to an extension bend  29   a  to  29   b  (in  FIG. 5 , only the extension bends  29   a ,  29   a   2  on one side of the flat card are shown), which in turn is fastened by way of screws onto the flat card panel  19   a  and  19   b  (in  FIG. 5 , only  19   a  is shown) on each side of the flat card. The flexible bends  17   a ,  17   b  (in  FIG. 5  only  17   a  is shown) are fastened by way of screws to the side panels  19   a  and  19   b , respectively. Reference numeral  24   a  denotes the machine frame. 
     A sensor  38   1 , is mounted at the immobile extension bend  29   a   2  and a sensor  38   2  is mounted at the immobile side panel  19   a . The sensors  38   1 , and  38   2 , for example piezo-ceramic sensors, register minimal component movements by measuring structure-borne noise. 
       FIG. 6  shows an embodiment in which a sensor  39   1  is mounted at the fixed carding element  27  and a sensor  39   2  is mounted at the suction hood  30 . The sensors  39   1 ,  39   2 , for example acceleration sensors, register minimal component movements by measuring acceleration. 
     Sensors  38   1 ,  38   2  and  39   1 ,  39   2  deliver an electronic signal in the event of contact between a component of the flat card, for example fixed carding clothing  27   a   1 , and a roller  4 , for example cylinder clothing  4   a , that is, in the event of contact between two components lying opposite to one another at a spacing a. The aim in that arrangement is to prevent or to avoid undesirable contact between a component and a high-speed roller. 
     Although the foregoing invention has been described in detail by way of illustration and example for purposes of understanding, it will be obvious that changes and modifications may be practised within the scope of the appended claims.