Abstract:
A fiber processing machine includes a roll having a direction of rotation and a clothing for carrying thereon fiber material; a cover partially circumferentially shrouding the roll; an air passage opening provided in the cover; an air guiding element bordering the air passage opening; a support for movably holding the air guiding element for varying a distance between the roll and the air guiding element; a pressure sensor for measuring a static pressure between the cover and the roll; and an arrangement for setting a position of the air guiding element as a function of the pressure measured by the pressure sensor.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a continuation of application Ser. No. 10/079,261 filed Feb. 21, 2002. 
     
    
     
         [0002]    This application claims the priority of German Application No. 101 10 824.9 filed Mar. 7, 2001, which is incorporated herein by reference.  
         BACKGROUND OF THE INVENTION  
         [0003]    This invention relates to a device incorporated in a fiber processing machine such as a card, a cleaner, an opener or the like for cleaning, for example, cotton or chemical fibers. The fiber processing machine includes a rapidly rotating roll shrouded by a cover (composed of cover elements) provided with at least one air passage opening. The air passage opening is, at its downstream end as viewed in the direction of roll rotation, bordered by an air guiding element whose distance from the roll is variable.  
           [0004]    In a known device the distance of the air guiding element from the roll is variable as a function of the removed quantities of waste such as trash, dust, fragments and the like.  
         SUMMARY OF THE INVENTION  
         [0005]    It is an object of the invention to provide an improved device of the above-outlined type.  
           [0006]    This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the fiber processing machine includes a roll having a direction of rotation and a clothing for carrying thereon fiber material; a cover at least partially circumferentially shrouding the roll; an air passage opening provided in the cover; an air guiding element bordering the air passage opening; a support for movably holding the air guiding element for varying a distance between the roll and the air guiding element; a pressure sensor for measuring a static pressure between the cover and the roll; and an arrangement for setting a position of the air guiding element as a function of the pressure measured by the pressure sensor.  
           [0007]    As a result of the measures according to the invention, an optimization of the working elements at the roll is feasible. In particular, an optimization at the separating elements, for example, separating knives is achieved with the aid of the air quantities and/or air stream, such as a pneumatic or a vacuum stream. It is a further advantage of the invention that in a simple manner additional air removal quantities and devices required therefor may be dispensed with because the air quantities exciting through air passage openings from regions where higher than atmospheric pressure (overpressure) prevails, may be introduced or drawn in through air passage openings provided in the vacuum zone. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 is a schematic side elevational view of a carding machine incorporating the invention.  
         [0009]    [0009]FIG. 2 is a fragmentary schematic side elevational view of a carding cylinder and a doffer, showing an embodiment of an adjustable air intake opening.  
         [0010]    [0010]FIG. 2 a  is an enlarged detail of FIG. 2.  
         [0011]    [0011]FIG. 3 is a view similar to FIG. 2 a  showing, in addition, a block diagram of a regulating device having a pressure sensor, a regulator and a setting member.  
         [0012]    [0012]FIG. 4 is a schematic side elevational view of licker-ins of a carding machine, provided with pressure sensors, air passage openings and air guiding elements.  
         [0013]    [0013]FIG. 5 is an enlarged detail of FIG. 4.  
         [0014]    [0014]FIG. 6 is a schematic side elevational view of a cleaner incorporating the invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]    [0015]FIG. 1 shows a carding machine CM which may be, for example, a high-performance DK 903 model, manufactured by Trützschler GmbH &amp; Co. KG, Mönchengladbach, Germany. The carding machine CM has a feed roller  1 , a feed table  2  cooperating therewith, licker-ins  3   a ,  3   b ,  3   c , a main carding cylinder  4  rotating in the direction  4   b  about the cylinder axis M, a doffer  5 , a stripping roll  6 , crushing rolls  7 ,  8 , a web guiding element  9 , a web trumpet  10 , calender rolls  11 ,  12 , a traveling flats assembly  13  having flat bars  14 , a coiler can  15  and a sliver coiler  16 .  
         [0016]    Underneath the cylinder  4 , between the doffer  5  and the licker-in  3   c , a cylinder cover  17  is disposed which has two waste outlet openings  18   a  and  18   b  leading into respective suction chambers  19   a  and  19   b . The waste outlet openings  18   a  and  18   b  are preceded—as viewed in the direction of rotation  4   b  of the cylinder  4 —by an air inlet opening  21   a  and an air outlet opening  21   b , respectively.  
         [0017]    Turning to FIGS. 2 and 2 a , the cover  17  is composed of a plurality of cover elements  17   I ,  17   II ,  17   III . The waste outlet opening  18   a  is preceded by the air inlet opening  21   a  and a further air inlet opening  21   c . While a non-regulated air stream B enters from the atmosphere through the air inlet opening  21   a , an air stream C which enters through the air inlet opening  21   c  is regulated. For this purpose an air guiding element  22  (air guiding vane) is provided which has a cylindrical bearing head  23  held in the cover part  17   II  for rotation in the direction of the arrows E, F. The other end of the air guiding element  22  is oriented in the rotary direction  4   b  of the cylinder  4 . By virtue of this arrangement the flow passage of the air inlet opening  21   c  may be gradually widened or narrowed.  
         [0018]    The air inlet opening  21   c  is preceded by a pressure measuring element  24  with which the static air pressure underneath the cylinder cover  17  (that is, in the clearance between the cover  17  and the cylinder clothing  4   a ) is measured. For this purpose a through bore is provided in the cover  17 . The pressure values are used for setting the distance a of the air guiding vane  22  from the points of the cylinder clothing  4   a . The setting of the position of the air guiding vane  22  may be effected manually in a manner not shown. Also, the position of the air guiding vane  22  may be, as shown in FIG. 3, automatically set as a function of the measured values of the pressure sensor  24 . For this purpose the pressure sensor  24  is associated with a transducer  25  which converts the pressure values into electric signals. The transducer  25  is connected to a regulator  26  (such as a microcomputer), having a desired value setter  27 . The regulator  26  is connected via a setting device, for example, a stepping motor,  28  with the air guiding element  22 . In the regulator  26  actual pressure values are compared with nominal pressure values and, in case of a deviation, signals representing such a deviation are applied to the motor  28 .  
         [0019]    During operation, through the air inlet openings  21   a  and  21   c , respective air streams B and C are drawn from the atmosphere by means of the vacuum prevailing in the gap between the cylinder cover  17  and the surface of the cylinder  4 . The air streams B and C impinge on the short fibers carried by the cylinder clothing  4   a  and loosen the hold of the clothing  4   a  on such short fibers. Thereafter, the short fibers are drawn through the waste outlet opening  18   a  into the suction chamber  19   a  and are removed via a conduit  36  which is coupled to a non-illustrated vacuum source. By means of the inflowing air streams B and C which exert a pressure on the short fibers and the vacuum stream D which exerts a pulling force on the short fibers, the removal force on the short fibers is greater than the retaining force of the cylinder clothing  4   a . In this manner, the short fibers are removed from the cylinder clothing to a greater extent than the long fibers still present on the cylinder clothing.  
         [0020]    Turning to FIG. 4, the three licker-ins  3   a ,  3   b  and  3   c  of a carding machine have a cover generally designated at  29 . The cover  29  is interrupted by air passage openings, by material transfer locations between two cooperating rolls, by air guiding elements  22   a - 22   g , separating knives  31   a ,  31   b  and stationary carding elements  30   a ,  30   b . At various locations of the cover  29  pressure sensors  24   a - 24   g  are provided. The pressure sensors  24   a - 24   g  are connected to the regulating device  26  of FIG. 3.  
         [0021]     As shown in FIG. 5, the licker-in  3   a  has a clothing formed of needles  3   I  and rotating in the direction  3   1 , the licker-in  3   b  has a relatively coarse sawtooth clothing  3   II  and rotates in the direction  32  and the licker-in  3   c  has a relatively fine sawtooth clothing  3   III  and rotates in the direction  33 . The rapidly rotating licker-ins  3   a ,  3   b  and  3   c  have an increasing circumferential velocity in the direction of material feed, that is, from the left to the right as viewed in FIG. 5. At an air passage opening  121  provided in the cover  29  downstream of the stationary carding element  30   b  as viewed in the direction of rotation of the roll  3   b , a vacuum prevails between the cover  29  and the roll clothing  3   II . At an air passage opening  21   II  provided in the cover  29  upstream of the stationary carding element  30   b  as viewed in the direction of rotation of the roll  3   b , an overpressure prevails between the cover  29  and the roll clothing  3   II . The pressure sensor  24   c  provides for a measurement of the vacuum whereas the pressure sensor  24   d  provides for a measurement of the overpressure. Between the air guiding element  22   d  and the clothing  3   II  a vacuum prevails whereas between the air guiding element  22   c  and the clothing  3   II  an overpressure is present. By virtue of the vacuum, air enters through the air passage opening  21   1  from the outside into the intermediate space between the cover  29  and the clothing  3   II  whereas by virtue of the overpressure, air escapes outward through the air passage opening  21   II  which is drawn away through the suction hood  19   a . In this manner the degree of separation of foreign particles such as trash and the like may be varied at the separating knives  31   a ,  31   b.    
         [0022]    Turning to FIG. 6, in a cleaning assembly which is disposed in a closed housing  37  and which may be a CVT 4  model manufactured by Trützschler GmbH &amp; Co. KG, Monchengladbach, Germany, the fiber material to be cleaned, such as cotton, is supplied, as indicated by the arrow K, to the feed rollers  1   a ,  1   b  as fiber tufts. The feed rollers  1   a ,  1   b  clamp the fiber material and advance it to a pin roll  32  having a circumferential velocity of 10-21 m/sec. The pin roll  32  is followed by a sawtooth roll  33  which has a circumferential velocity of approximately 15-25 m/sec. The roll  33  is followed by additional sawtooth rolls  34  and  35 . The rolls  32 - 35  have a diameter of approximately 150-300 mm.  
         [0023]    The roll  32  cooperates with a stationary carding element  30   I , a settable air guiding element  22   I , an air outlet opening  21   I , a separating knife  31   I  and pressure sensors  24   a  and  24   b.    
         [0024]    The roll  33  cooperates with a stationary carding element  30   II , a settable air guiding element  22   III , an air outlet opening  21   III , a separating knife  31   III  and a pressure sensor  24   d.    
         [0025]    The roll  34  cooperates with a stationary carding element  30   IV , a settable air guiding element  22   IV , an air outlet opening  21   IV , a separating knife  31   IV  and pressure sensors  24   e  and  24   f.    
         [0026]    The roll  35  cooperates with a stationary carding element  30   IV  a settable air guiding element  22   IV  an air outlet opening  21   IV , a separating knife  31   IV  and a pressure sensor  24   h.    
         [0027]    Respective suction hoods  29   I - 29   IV  are associated with separating knives  311 - 314 . The working direction of the cleaner is designated at G. The pressure sensors  24   a - 24   h  and the settable air guiding elements  22   I - 22   IV  are connected to an electronic control and regulating device, for example, a microcomputer, as shown in FIG. 3.  
         [0028]    It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.