Abstract:
The invention relates to a textile machine comprising a sliver channel ( 2 ) arranged in a rotating plate ( 1 ) for a cycloid-shaped deposit of a fiber sliver in a can. The sliver channel ( 2 ) is characterized in that the cross-section thereof is divided into a guiding cross-section ( 4 ) and a remaining cross-section ( 5 ). The invention also relates to a method for guiding a fiber sliver within a sliver channel ( 2 ), characterized in that the tensioning of the fiber sliver is such that the fiber sliver extends in a guiding cross-section ( 4 ) in the sliver channel ( 2 ).

Description:
BACKGROUND  
       [0001]     The present invention relates to a textile machine with a sliver channel arranged in a rotating plate for a cycloid-shaped deposit of a fiber sliver in a can.  
         [0002]     Textile machines, in particular cards and draw frames are known, in which a fiber sliver is guided through a rotating plate with a sliver channel after being produced or treated. The rotating plate rotates above a can into which the fiber sliver is deposited in a cycloid-shaped manner.  
         [0003]     The sliver channel is normally a straight or curved pipe to guide the fiber sliver generally from a calendar roller to the spinning can in such manner that the fiber sliver may not suffer any wrong draft if at all possible. A wrong draft can occur if the fiber sliver is stretched, e.g. by friction, against the wall of the sliver channel during simultaneous drafting. This is especially a disadvantage when the fiber sliver has been evened out previously in a high-precision regulating draw frame. The regulation carried out before is thus again undone. Especially at high delivery speeds and high rotational speeds of the rotating plate, the forces acting upon the fiber sliver are detrimental in this respect.  
       SUMMARY  
       [0004]     It is a principal object of the present invention to provide a rotating plate sliver channel that avoids the above-mentioned disadvantages and in particular avoids wrong drafts at high delivery speeds to a great extent. Additional objects and advantages of the invention are set forth below in the following description, or may be obvious from the description, or may be learned through practice of the invention.  
         [0005]     By configuring the sliver channel cross-section in accordance with the invention so that the sliver channel is subdivided into a guiding cross-section and a remaining cross-section, the fiber sliver is caused to assume a predetermined ideal line through the guiding cross-section which is provided in particular throughout the entire sliver channel from the input to the output. It is assumed in this case that, taking into account the forces acting upon the fiber sliver, the ideal line represents the shortest path for the fiber sliver through the sliver channel. By subdividing the sliver channel into a guiding cross section and a remaining cross-section, the overall cross-section of the sliver channel is made sufficiently large for the introduction of the fiber sliver into the sliver channel. On the other hand, the guiding cross-section of the sliver channel acting upon the fiber sliver as it goes through the sliver channel is sized so that a more precise guidance of the fiber sliver is achieved than in a conventional sliver channel.  
         [0006]     In the present invention, it was recognized that the sliver channel must perform different tasks. On the one hand it must be sufficiently large at the introduction of the fiber sliver into the sliver channel, i.e. when the deposit of a new fiber sliver into a can begins, so that the fiber sliver can be threaded either manually or by auxiliary mechanical or pneumatic means through the sliver channel. On the other hand the large cross-section required here is troublesome for the depositing of the fiber sliver, i.e. for the actual operation of the textile machine. Here, a sliver channel that is too large would enable the fiber sliver to move in an uncontrolled manner, rendering the deposit of the fiber sliver uneven and in addition easily causes wrong drafts.  
         [0007]     It is therefore proposed according to the invention that a guiding cross-section and a remaining cross-section of the sliver channel be provided. Here, the guiding cross-section is sized so that it compresses the fiber sliver, or at least imposes a very precise guidance upon the fiber sliver. The additional remaining cross-section facilitates the introduction of the fiber sliver into the sliver channel. If the fiber sliver is compressed in the guiding cross-section, the fiber adhesion, i.e. the friction of the individual fibers against each other and thereby the cohesion of the fiber sliver is increased. Thereby the danger of a wrong draft is reduced, since a greater traction (of equal significance as a greater tensile force) can be applied to the fiber sliver without shifting of the individual fibers relative to each other whereby the number of fibers per cross-section in the fiber sliver would be reduced.  
         [0008]     In order to compress the fiber sliver, the guiding cross-section is advantageously designed so that the walls of the sliver channel in the vicinity of the guiding cross-section converge at least in part at a sharp angle. Thereby and due to the rotational movement and the centrifugal force acting upon the fiber sliver, the latter is pressed into the guiding cross-section and adhesion is increased. Alternatively a different, suitable design of the guiding cross-section at the circumference of the sliver channel can cause the centrifugal force to press the fiber sliver more or less forcefully into the guiding cross-section. This can even go so far that the centrifugal force acting on the fiber sliver takes effect outside the guiding cross-section so that the fiber sliver is held in the guiding cross-section merely by the tensile force of the fiber sliver.  
         [0009]     In an advantageous embodiment of the invention, the remaining and/or the guiding cross section change form in the course of the sliver channel so that the fiber sliver can be influenced to meet different requirements.  
         [0010]     It has been shown to be especially advantageous if the guiding cross-section guides the fiber sliver essentially interlockingly. As a result, the guidance of the fiber sliver is especially gentle and at the same time the introduction of the fiber sliver into the sliver channel and into the guiding cross-section is facilitated.  
         [0011]     In an especially simple embodiment, the guiding cross-section is cup-shaped. In this embodiment, the fiber sliver extends within the cup. In that case, it could even be possible to dispense with the walls of the remaining cross-section. The remaining cross-section is then open in this embodiment, or at least extensively open. The sliver channel here merely consists of a straight or coiled cup in which the fiber sliver is guided.  
         [0012]     It is normally advantageous if the remaining cross-section is larger than the guiding cross-section. The remaining cross-section which is provided in particular for the introduction of the fiber sliver and for the removal of the air transported together with it, can exert the least possible negative influence on the fiber sliver with this large design. The fiber sliver will then barely come into contact with the walls of the remaining cross-section. The guiding cross-section on the other hand, exerts a sufficiently great force on the fiber sliver so that it can be guided along its ideal line through the sliver channel and if necessary can also be compressed, so that a greater traction can be exerted on the fiber sliver.  
         [0013]     An especially advantageous and even independent invention provides for the remaining cross-section and/or the guiding cross-section be subjected to suction. Thereby, fine dust or individual fibers present in the sliver channel can be sucked away. The so-called “mice” that may form in the sliver channel during the operation of the rotating plate and may fall into the spinning cans in the form of dirt can be prevented in this manner, since the particles from which the mice are formed have already been removed individually from the sliver channel. The suction to which the sliver channel is subjected, especially if it has a remaining cross-section and/or a guiding cross-section, can be effected in this case from one end or from both ends of the sliver channel, or else, in a special embodiment, through wall openings made in the remaining cross-section and/or in the guiding cross-section of the sliver channel. The removal of dust and other particles from the sliver channel without influencing the fiber sliver negatively can be effected very reliable in particular through wall openings in the remaining cross-section. If the suction takes place in the area of the guiding cross-section, this further increases the compression of the fiber sliver within the guiding cross-section and as a result an even greater traction force can be applied to the fiber sliver.  
         [0014]     If the sliver channel is formed so that the remaining cross-section and the guiding cross-section represent separate components connected to each other, the product ion of the sliver channel as well as a possibly machining of the surface inside the sliver channel can be effected very easily. Contrary to the conventional sliver channels, a composition from several components presents no problem with the sliver channel according to the invention because the fiber sliver is essentially guided in the guiding segment only and not in the remaining cross-section of the sliver channel. The interface between the guiding cross-section and the remaining cross-section of the sliver channel can thus be laid out in an area in which a fiber sliver does not normally run so that the danger that fibers may be wedged in, leading to interference with the uniformity of the fiber sliver, are avoided.  
         [0015]     The remaining cross-section and the guiding cross-section of the sliver channel are advantageously separated from each other at least partly by a wall. Thereby the guidance of the fiber sliver can be assisted by the wall in areas where it should take place within the guiding cross-section but where this is difficult to realize. On the other hand, the remaining cross-section can be made large enough in that case so that possible airflow or dirt removal continues to be possible.  
         [0016]     It is especially advantageous if a corresponding wall is located at the end of the sliver channel towards the can. Here in particular, the wall can be used to remove the accumulated and collected dirt from the sliver channel without letting it fall into the can. In that case, the opening of the remaining cross-section that transports the dirt can be designed in such a manner that it lets out into a dirt suction system through which the accumulated dirt is removed. In a simpler embodiment, a dirt catching receptacle can be provided at the remaining cross-section in which the dirt that is taken through the remaining cross-section can be collected and emptied as needed.  
         [0017]     In order to achieve especially good guidance of the fiber sliver at the sliver channel output, the end of the sliver channel towards the can may be made smaller than the rest of the sliver channel. Thereby a very precise guidance of the sliver is obtained at the sliver channel output, and thereby the deposit of the fiber sliver in the sliver channel is increased.  
         [0018]     In sliver channels of the state of the art, it was customary in the past to keep the output cross-section relatively large in order to compensate for tension peaks acting upon the fiber sliver. The pressing of the fiber sliver into the guiding cross-section now makes a greater traction force on the fiber sliver possible without damaging the fiber sliver, so that the output cross-section of the sliver channel can be made narrower and the deposit of the fiber sliver in the can would be improved.  
         [0019]     For the pneumatic introduction of the fiber sliver into the sliver channel, it is possible to design the openings of the sliver channel, in particular the opening of the remaining cross-section, so that they can be closed in order for the stream to emerge only through the guiding cross section at the end of the sliver channel and thus carry the fiber sliver with it. Following the pneumatic introduction of the fiber sliver, the opening of the sliver channel can be opened again. The openings of the sliver channel can also be closed entirely or partially during operation in order to adjust the stream management within the sliver channel.  
         [0020]     Another embodiment of the invention provides for the inside surface of the sliver channel to be at least partially coated. This coating may be such as to make friction-less sliding of the fiber sliver against the surface of the sliver channel possible. To avoid the accumulation of dirt on the inside walls of the sliver channel, it is advantageous to provide an anti-adhesion coating at least partially on the fiber sliver channel. It can be especially advantageous if the coating is especially friction-free in the area of the guiding cross-section, while an anti-adhesion coating is applied in the area of the remaining cross-section. This differentiated coating can be achieved without difficulty, e.g. through a design of the sliver channel in several parts. Other realizations of a uniform coating or different coatings in different sliver channel sections are possible. It is equally advantageous if the sliver channel is made of a low-friction material.  
         [0021]     In general, all measures that reduce the tensile traction and/or the frictional forces acting upon the fiber sliver are preferred.  
         [0022]     In a process according to the invention of the guidance of a fiber sliver in the sliver channel, the traction on the fiber sliver is such that the fiber sliver runs in a guiding cross-section of the sliver channel provided for this. The fiber sliver is then guided in a suitably designed guiding cross-section of the sliver channel in which the fiber sliver is conveyed by the traction in direction of the guiding cross-section. The traction can be greater than for conventional fiber slivers because of the design of the guiding cross-section, since the compression of the fiber sliver within the guiding cross-section permits an increase of traction force. It is even possible to process thin slivers that could no longer be drafted by conventional machines by means of the invention.  
         [0023]     If an air stream, in particular suction, is produced according to the invention along the inner surface of the sliver channel, at least in the area of the remaining cross-section of the sliver channel, this air stream can be used for the removal of dirt present inside the sliver channel. The air stream can be produced actively, by means of a suction or blowing device, as well as passively, through the configuration of the sliver channel and through its rotation.  
         [0024]     Additional advantages of the invention are shown in the embodiments below. 
     
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0025]      FIG. 1  shows a top view of a rotating plate,  
         [0026]      FIG. 2  shows a section AA through  FIG. 1 ,  
         [0027]      FIGS. 3   a  to  c  show a view of three sides of a sliver channel and  
         [0028]      FIG. 4  shows another embodiment of a sliver channel. 
     
    
     DETAILED DESCRIPTION  
       [0029]     Reference will now be made in detail to embodiments of the invention, one or more examples of which are shown in the drawings. The embodiments are provided by way of explanation of the invention, and not as a limitation of the invention. It is intended that the invention include modifications and variations to the embodiments described herein.  
         [0030]      FIG. 1  shows a rotating plate  1  in which a sliver channel  2  is provided. The sliver channel  2  starts near the central axis of the rotating plate  1  and ends on the bottom of the rotating plate  1  with an approximately kidney-shaped opening cross-section. The sliver channel  2  is attached in the usual manner in the rotating plate  1 , e.g. by means of a poured mass  3 .  
         [0031]     The sliver channel  2  has a round cross-section. The cross-section consists of a guiding cross-section  4  and a remaining cross-section  5 . The guiding cross-section  4  in this embodiment is a partial circle connected to another partial circle of the remaining cross-section  5 . The partial circle of the guiding cross-section  4  has a clearly shorter radius than the partial circle of the remaining cross-section  5 . As a result, the fiber sliver entering the guiding cross-section  4  is more compressed and can sustain a greater traction force without damage to the fiber sliver, as described earlier.  
         [0032]     The placement of the guiding cross-section  4  relative to the position of the remaining cross-section  5  can also be different from that indicated in this embodiment. The arrangement of the guiding cross-section  4  as drawn here shows the position that the fiber sliver would essentially assume automatically when the rotating plate  1  rotates and the fiber sliver is deposited in a can. Thanks to the compression of the fiber sliver in the guiding cross-section with relatively short radius, the strength of the fiber sliver is increased, so that the depositing speed can be increased without damaging the fiber sliver. It is also possible to produce a rotation in the fiber sliver to further increase the strength of the fiber sliver.  
         [0033]      FIG. 2  shows the section AA from  FIG. 1 . The sliver channel  2  is here partially cut. At the upper end of the sliver channel  2  a fiber sliver which is not shown enters the sliver channel  2  and runs through the sliver channel  2 . At the lower end of the drawing, the fiber sliver emerges and is deposited in a can which is not shown and which is standing under the rotating plate  1 . From the section through the sliver channel  2 , it can be seen that the guiding cross-section  4  represents a raised area in the cross-section of the sliver channel  2 . The fiber sliver follows this rise and is further compressed by the cross-section that is smaller than the rest of the sliver channel  2  since it is unable to spread out because of the form of the sliver channel  2  at that point.  
         [0034]      FIG. 3  shows three sides of a sliver channel  2  (“a” through “c”). The sliver channel  2  in the drawing of  FIG. 3   a  is shown in a side view. The guiding cross-section  4  extends in a raised groove along the sliver channel  2  from its one end to the other end. The remaining cross-section  5  constitutes the essential volume of the sliver channel  2 . While the air, as well as part of the fiber sliver, is transported in the remaining cross-section  5 , the fiber sliver is applied in the guiding cross-section  4 . Due to the shorter radius of the guiding cross-section  4 , a greater force is exerted upon the fiber sliver and thereby the fiber sliver is compressed more than in a cross-section with the radius of the remaining cross-section  5 .  
         [0035]     In order to clearly show the cross-section,  FIG. 3   b  shows another side view and the drawing of  FIG. 3   c  shows a top view of the sliver channel  2 . Especially in the top view of the sliver channel  2 , it can be seen that the radius r 1  of the remaining cross-section  5  is clearly larger than the radius r 2  of the guiding cross-section  4 .  
         [0036]     The walls of the guiding cross-section  4  and of the remaining cross-section  5  can be made from two different parts that are connected to each other. The connection can be achieved e.g. by soldering. A screw connection is however also possible. The separating line can be located in the shown curve between guiding cross-section  4  and remaining cross-section  5 . It is however also possible for the separation of the sliver channel  2  to take place e.g. exclusively in the area of the remaining cross-section  5 , for example instead of the interface points between the broken center line  6  and the wall of the remaining cross-section  5 . In this area, the contact between the wall and the fiber sliver barely applies, so that damage to the fiber sliver caused by a possible separating line can be avoided.  
         [0037]      FIG. 4  shows a lateral view of another embodiment of a sliver channel  2 . This sliver channel  2  has a guiding cross-section  4  and a remaining cross-section  5 . The output end of the remaining cross-section  5  is partially covered here by a cover  7 . In the area of the cover  7 , a separating wall  8  extending into the sliver channel  2  is provided. In addition, an opening  9  is provided at the lower end of the sliver channel  2 , through which dirt or dust particles can be aspired. The suction is effected either by a suction device that is not shown and which is installed at the opening  9 , or through injector effect which automatically produces a suction effect in the remaining cross-section  5  due to the rotation of the sliver channel  2  and which can exit e.g. through the opening  9 .  
         [0038]     The separating wall  8  and the cover  7  reduce the output cross-section of the sliver channel  2  for the fiber sliver so as to be smaller than in an embodiment without cover  7 . As a result, a precise deposit of the fiber sliver in the can is possible. The cover  7  can cover the rear portion of the remaining cross-section  5  or can be extended laterally into the area of the guiding cross-section  4 . The separating wall  8  can be provided on its end away from the output end of the sliver channel  2  with a chamfering pointing away from the guiding cross-section in order to facilitate the introduction of the fiber sliver and to prevent the fiber sliver from being guided into the area of the cover  7 .  
         [0039]     The openings  10  which are located in the area of the remaining cross-section  5  also serve for the removal of dust and dirt particles. This removal of dust and dirt particles can be effected with special efficiency if the area in which the rotating plate is located is subjected to negative pressure and a suction effect acts upon the interior of the sliver channel  2 . The removal of dirt particles thorough the openings  9  or  10  make it possible to effectively avoid so-called mice. In a special, not shown embodiment, the openings  9  and  10  can be designed so that their size can be adjusted. This makes it possible to adapt the sliver channel  2  to certain kinds of dirt on the fiber sliver or to certain qualities of the fiber sliver. The opening  9  can be connected to a negative pressure system as well as to a dirt collection container which is not shown and in which the dirt particles are collected. From there, they must be emptied as needed.  
         [0040]     The invention is not limited to the examples discussed. Thus the configuration of the cross-section of the sliver channel  2  in particular can be different, i.e. the form of the guiding cross-section as well as the form of the remaining cross section can be different. The essential point is that the fiber sliver be given guidance in the guiding cross-section so that the sliver deposit may thus take place in a clean and rapid manner.