Abstract:
An apparatus for lengthening, to a determined extent, a free sliver end portion hanging on an exterior face and from an upper edge of a can containing sliver deposited in coils, includes a device for grasping and firmly holding the free sliver end portion; and an arrangement for moving the grasping device and the can away from one another for pulling an additional length of sliver from the can to lengthen the free sliver end portion.

Description:
REFERENCE TO RELATED APPLICATION  
       [0001]    This application is a continuation of U.S. patent application Ser. No. 09/632,790 filed Aug. 4, 2000. 
     
    
     
         [0002]    This application claims the priority of German Application No. 199 36 703.5 filed Aug. 4, 1999, which is incorporated herein by reference.  
         BACKGROUND OF THE INVENTION  
         [0003]    This invention relates to a device for depositing sliver into a coiler can, particularly a flat coiler can having an elongated horizontal cross-sectional shape. Further, the invention concerns in particular a coiler can used in conjunction with a draw frame or a carding machine, wherein the sliver is deposited into the coiler can in coils and the free sliver end hangs from an upper can edge in a downward orientation at the outside of the coiler can.  
           [0004]    In practice, the sliver is advanced in a sliver guiding channel of a rotary coiler head and fills, in coil layers, a coiler can which is positioned underneath the coiler head. During the filling operation the flat coiler can is horizontally reciprocated. When the coiler can is full, it is moved a predetermined distance from a zone underneath the coiler head. During this occurrence the sliver is still connected to the coiler head and extends to the uppermost coil layer in the coiler can. Subsequently the sliver is severed, for example, by means of a mechanical severing device. In this manner, a free sliver end is obtained which, because of the significant distance between the coiler can and the coiler head, has an appreciable length as it hangs down along the outside of the coiler can. In such a process first the final length of the free sliver end is obtained and subsequently the sliver is severed.  
           [0005]    It is a disadvantage of the above-outlined conventional arrangement that an accurate length of the free sliver end cannot always be obtained. It may happen that the overhanging sliver end is excessively long for the subsequent processing during which the sliver end has to be accurately grasped to ensure that it is securely advanced to a processing apparatus. Further, the exact positioning and orientation with respect to the coiler can in case of a long sliver end is not ensured.  
           [0006]    German patent document No. 195 48 232 to which corresponds U.S. Pat. No. 5,621,948 discloses an apparatus wherein the draft of a draw frame situated upstream of the sliver outlet opening is briefly increased such that a reduced cross section at a location of the sliver bundle is obtained. The combined sliver subsequently produced from the sliver bundle runs, with the reduced cross-sectional location, through the entire sliver channel of the coiler head up to the outlet opening. When the location of reduced thickness has reached the deflecting edge at the outlet of the sliver channel, the sliver is severed by virtue of the fact that the coiler can is moved away horizontally. Stated differently, the distance between the sliver outlet opening and the uppermost coiler layer in the coiler can is increased such that the sliver ruptures at the location of reduced thickness without the need of an additional severing device. Upon initiating the sliver severing process, one of the narrow walls of the flat coiler can is situated approximately below the severing edge. If the middle of the flat can were positioned below the severing edge, then upon moving the can away, additional deposited sliver coils would be dragged along which would be an undesired occurrence. In particular, the sliver end would be situated on top of the uppermost coil layer of the sliver rather than hanging laterally outside the coiler can. When the location of reduced thickness in the sliver is situated on the deflecting edge and the narrow wall of the coiler can is positioned below the deflecting edge, the coiler can is moved away, resulting in an excessively short free sliver end at the coiler can. A short sliver end is not adapted for being automatically grasped and admitted to the feeding device of an after-connected processing machine, for example, a spinning machine.  
         SUMMARY OF THE INVENTION  
         [0007]    It is an object of the invention to provide an improved device and method of the above-outlined type from which the discussed disadvantages are eliminated and which, in particular, is capable of producing, in a simple manner, a free sliver end with a sufficient and accurately predetermined length.  
           [0008]    This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the apparatus for lengthening, to a determined extent, a free sliver end portion hanging on an exterior face and from an upper edge of a can containing sliver deposited in coils, includes a device for grasping and firmly holding the free sliver end portion, and an arrangement for moving the grasping device and the can away from one another for pulling an additional length of sliver from the can to lengthen the free sliver end portion.  
           [0009]    Thus, first the sliver is severed between the coiler can and the outlet opening of the coiler head and subsequently, according to the invention, the precise, predetermined length of the sliver end is produced. According to the invention, between the end of the hanging sliver and the coiler can a defined relative motion is obtained. In particular, the sliver end is fixed and subsequently, the coiler can is horizontally shifted. Thus, the end portion of the sliver is lengthened by the removal and linear orientation of a sliver coil from the uppermost sliver layer of the sliver deposited in the coiler can. In this manner, a free sliver end with an accurately predeterminable length is obtained. Further, the position of the sliver may be precisely determined in relation to the can wall on which it hangs, so that in this manner too, a further processing of the sliver is improved. By virtue of the exact length and position of the free sliver end an automatic start of the successive machine is feasible.  
           [0010]    The invention has the following additional advantageous features:  
           [0011]    Upon severance of the sliver the distance between the outlet end of a coiler head which deposits the sliver into the can in coils and a can wall closest to the coiler head is about 30 to 90 mm.  
           [0012]    After severing the sliver, the extended length of the free sliver end portion corresponds essentially to the distance between the can wall closest to the coiler head and the sliver outlet opening of the coiler head.  
           [0013]    The period during which the free sliver end portion is firmly held is determined by the control device of the sliver producing machine at which the sliver is deposited by the coiler head.  
           [0014]    The extended free sliver end portion has a length of about 90-140 mm, preferably between about 120-130 mm.  
           [0015]    The device which grasps and firmly holds the free sliver end portion is a mechanical clamping element.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0016]    [0016]FIG. 1 is a schematic side elevational view of a draw frame and a reciprocated flat coiler can filled with sliver.  
         [0017]    [0017]FIG. 2 is a schematic side elevational view illustrating the passage of the sliver through the draw unit and showing a location of reduced sliver thickness.  
         [0018]    FIGS.  3 A- 3 D are schematic side elevational views showing consecutive operational phases in lengthening a short sliver end.  
         [0019]    [0019]FIG. 4 is a fragmentary front elevational view of a rectangular, flat coiler can (one of the two narrow faces thereof being visible), illustrating a short and a lengthened sliver end.  
         [0020]    [0020]FIG. 5 is a schematic side elevational view of a pneumatic suction device operating as a sliver hold-down element. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]    [0021]FIG. 1 illustrates a regulated, high-performance draw frame  1  which may be an HSR 1000 Model manufactured by Trützschler GmbH &amp; Co. KG, Mönchengladbach, Germany. The slivers enter the draw unit of the draw frame from non-illustrated coiler cans, and after a drawing operation the plurality of slivers are combined into a single sliver which subsequently passes through a rotary coiler head  2 . The latter deposits the sliver in coils into a flat coiler can  3  which is reciprocated in the direction of arrows A and B. The coiler can has an elongated, generally rectangular horizontal cross-sectional shape; in FIG. 1 one of the two opposite large sides of the coiler can  3  is visible. The coiler can  3 , after being filled with the sliver  4 , is moved out from under the coiler head  2  in the direction of the arrow C. During this occurrence the sliver is severed at a location thereof, and the sliver end of the coiled sliver contained in the coiler can  3  hangs loosely over the edge of one of the narrow end faces of the coiler can  3 . A cover plate  10  extends over the top of the sliver fill as the coiler can  3  moves away in the direction of the arrow C; the cover plate  10  adjoins a carrier plate  11  as shown in FIG. 3A.  
         [0022]    In FIG. 2 a 4-over-3 draw unit is shown, having a preliminary drawing field a′ and a principal drawing field b′. The slivers  5  run through the draw unit in the direction of the arrow D. The sliver has a thinned (cross-sectionally reduced) location  6  which is obtained by a short-period speed increase of the output rolls of the draw unit. The slivers  5  enter a sliver trumpet  7  from which a combined sliver is pulled off by delivery rolls  8 ,  9 . The sliver subsequently passes through a sliver channel  2   a  of the coiler head  2  from the sliver inlet opening  2   b  to the sliver outlet opening  2   c  and is thereafter deposited into the coiler can  3  which is horizontally reciprocated underneath the coiler head  2 .  
         [0023]    As shown in FIG. 3A, the filled coiler  3  is pushed out of the draw frame  1  in such a manner that one of the two narrow end walls  3   a  is situated approximately underneath the free end of the cover plate  10 . The short (approximately 40 mm) sliver end  4   a  hangs downwardly from the upper edge of the can wall  3   a . In the region of the free end of the cover plate  10  a pneumatic suction device  12  is arranged which is shown in more detail in FIG. 5. Upon turning on a suction stream E as shown in FIG. 3B, the short band end  4   a  is drawn upwardly against the cover plate  10  and is firmly held there by the force of the suction stream E. Thereafter, the coiler can  3  is, as shown in FIG. 3C, further shifted in the direction of the arrow F whereby a lengthened band end  4   b  is obtained. Subsequently, the suction stream E is turned off so that the lengthened band end  4   b  drops down from the suction device  12  and remains hanging on the end wall  3   a  by gravity.  
         [0024]    In FIG. 4 the short sliver end  4   a  (whose terminal edge is shown in broken lines) and the lengthened sliver end  4   b  (whose terminal edge is shown in solid lines) are illustrated. The short sliver end  4   a  has a length a which extends from the upper edge of the can wall  3   a  to the free edge of the short sliver end. The lengthened sliver end  4   b  has a length b of, for example, 125 mm, extending from the upper edge of the wall  3   a  to the free sliver edge (shown in solid lines). The lengthened free sliver end  4   b  is situated in a generally rectangular “tolerance window”  13  which has a length c of approximately 50 mm and a width d of approximately 30 mm. The upper edge of the can wall  3   a  has a distance e of approximately 90 mm from the upper boundary and a distance f of approximately 140 mm from lower boundary of the tolerance window  13 . The center line  14  of the coiler can wall  3   a  and that of the tolerance window  13  coincide. The distance g of the center line  14  from the large (wide) can wall  3   b  is approximately 60 mm.  
         [0025]    The suction device  12  shown in FIGS. 1, 3A and  5  has a suction channel  12   a  provided at its end with a suction opening which is flush with the lower surface  10 ′ of the cover plate  10 . The other end of the suction channel  12   a  is coupled to a suction conduit  15  which leads to a non-illustrated vacuum source which, in turn, is energized or de-energized by an electronic control device, also not illustrated. In FIG. 5 the direction of the vacuum stream flow is designated at E.  
         [0026]    Reverting to FIG. 4, the lengthened sliver end  4   b  of defined length b which is obtained according to the invention and which hangs down laterally on the outside of the full coiler can  3 , has advantages both for a manual and for an automatic handling.  
         [0027]    If the sliver is to be manually threaded into a successive processing machine, for example, a spinning machine, locating and grasping the end  4   b  of the sliver is facilitated for the machine operator.  
         [0028]    In case of an automated sliver insertion into the successive processing machine, the downwardly hanging sliver end  4   b  is even a precondition for an automatic operation. The recognition and the reproducible secure grasping of the sliver end  4   b  of the coiled fiber mass  4  without entraining additional coils therefrom is made possible in a simple manner. Therefore, in case of an automatic sliver insertion into a spinning machine a tolerance window is provided where the sliver end  4   b  must be located to ensure an operationally reliable functioning of the sliver insertion arrangement.  
         [0029]    The invention may also be used for inserting slivers in creels for draw frames, flyers or air jet machines.  
         [0030]    As a complementation of the sliver severing device the invention provides a device and a method for obtaining a sliver end of definite length hanging externally over an upper edge of the coiler can. A fixing, for example, clamping of the short sliver end  4   a  is effected preferably by the suction device  12  mounted on the fiber processing machine during a transporting motion in the direction of the arrow F of the full coiler can  3  in such a manner that the clamping element and the coiler can  3  are moved briefly away from one another as shown, for example, in FIG. 3C, whereby the short sliver end  4   a  is pulled out of the coiler can  3 . The length b of the extended sliver end  4   b  which hangs loosely after being released, may be determined by setting the clamping period. For pulling out the short sliver end  4   a , an already present motion process, such as the reciprocating motion of the coiler can  3 , may be utilized. The clamping period has to be predetermined by the machine control to adapt the length b of the downwardly hanging extended sliver end  4   b  to the conditions prevailing in the successive fiber processing machine or to be able to obtain an extended sliver end  4   b  even in case of coiler cans which do not have an upwardly spring-urged movable bottom.  
         [0031]    It is to be understood that for practicing the invention the coiler can may have a circular or square horizontal cross section. In such a case the shift of the can away from the coiler head is linear for a rectangular coiler can (as in case of a flat can) or at least approximately circular in case of a round can. In case the clamping element is a pneumatic suction device  12 , the searching and clamping of the sliver end  14   a  may be performed in a simple manner.  
         [0032]    The invention was described in connection with an example in which the clamping element is provided in the coiler cover of the processing machine, namely in the cover plate  10  of a flat can filling station of the high-performance draw frame HSR 1000. It is to be understood that the invention may be utilized in a similar manner by an apparatus which is independent from the sliver producing machine such as a draw frame.  
         [0033]    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.