Lap evener for a fiber processing machine
CROSS REFERENCE TO RELATED APPLICATION 
     U.S. patent application Ser. No. 07/261,519, filed October 3, 1988 and entitled Apparatus For Feeding A Fiber Lap To A Fiber Processing Machine and being the counterpart of Federal Republic of Germany Application No. P 37 33 632.0 discloses related subject matter and is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     This invention relates to an apparatus which is associated with a card, a roller card unit, a cleaner or a similar textile fiber processing machine and which serves for evening the fiber lap fed to the fiber processing machine. Upstream of the fiber processing machine, a fiber tuft feeding device such as a feed chute is arranged which discharges a fiber lap, subsequently advanced by a feed roller to a fiber processing roller (such as a licker-in for a card or an opening roller for a cleaner). A counterelement, such as a feed table or a counterroller cooperates with the feed roller to advance the fiber lap therebetween. Either the feed roller or the counterelement is supported stationarily, while in each instance the respective other component executes excursions to thus vary the gap between the feed roller and the counterelement. 
     It is known to provide for the fiber lap a transfer element such as a transfer tray between the discharge end of the feed chute and the feed roller. The fiber lap discharged downwardly from the feed chute is deflected by the transfer element from a vertical direction to an approximately horizontal orientation. This change in direction alters the inner structure of the fiber lap. Further, deflecting, guiding and compressing elements are also present which adversely affect the uniformity of the fiber lap. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provide a fiber lap evener of the above-outlined type from which the discussed disadvantages are eliminated and which, in particular, provides for a greater uniformity of the fiber lap. 
     This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the discharge end of the feed chute terminates immediately adjacent the feed roller so that the feed roller draws the fiber material from the feed chute, and a device is provided which generates a signal that represents the width of the gap which is defined between the feed roller and the counterelement and which varies by virtue of the excursions of either the feed roller or the counterelement in response to the quantity fluctuations of the fiber lap passing therebetween. The signal is applied to a control device which is connected to the drive motor of the feed roller to thus regulate the feed roller speed as a function of the fiber lap quantities passing through the gap. 
     Thus, according to the invention, components such as an intermediate element, a transfer tray, a support roller or the like which are conventionally arranged between the discharge end of the feed chute and the feed roller are dispensed with. The drawings and transporting function of the feed roller/counterelement assembly is assisted by gravity acting on the fiber lap, as well as by the fiber tuft densifying (compressing) device situated in the lower, or feed chute of a two-chute card feeder. By virtue of the fact that the conventional deflecting, guiding and compressing elements are omitted according to the invention, the usual multiple shifts the fiber lap which cause structural changes and irregularities in the fiber lap, can no longer occur. 
     It is known, for example, that the extent of draft between the delivery rollers at the bottom of the feed chute and the feed roller associated with the card has a significant effect on the uniformity of the sliver produced by the card: thus, unfavorable drafts may cause significant errors. The invention eliminates the sources of such errors. Even in case of a favorable draft, reorientations occur which are eliminated by the invention. The fiber lap is admitted in a more state (considered both over a time period and along the width of material at any given time) to the opening roller of the fiber processing machine, such as the licker-in of a card. A uniform advance of the fiber lap throughout its width is ensured by the fact that the transporting device, that is, the feed roller, is situated in the immediate vicinity of the opening roller (licker-in). This arrangement results in better Uster values and CV values. 
     By associating the movable component of the feed roller/counterelement assembly with a measuring member to sense the excursion of the movable member as a function of the throughgoing fiber material and using the sensor signal to increase or decrease the rpm of the feed roller dependent upon the thickness variations, there is achieved a short-period regulation. The direct feed, achieved by arranging the feed chute terminus immediately at the feed roller and the short-period regulation cooperate with one another for improving the uniformity of the fiber lap. Only a very narrow space is needed to accomplish these measures; this circumstance advantageously results in a compact and structurally simple apparatus. 
     Preferably, the discharge end of the feed chute terminates at a location which is generally above the center of the opening roller (licker-in) of the fiber processing machine. 
     According to further advantageous features of the invention, the movable counterelement is spring-biased, for example, by a spring weight. According to another advantageous feature of the invention, the counterelement is an independient sensor element. Preferably, the measuring member is an inductive path measuring device. According to a further advantageous feature of the invention, the measuring element is connected to the drive motor of the feed roller with the intermediary of the control device. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a schematic side elevational view of a carding machine and an associated, upstream-arranged feed chute, incorporating a preferred embodiment of the invention. 
     FIGS. 2-6 are each diagrammatic side elevational views of five further preferred emdodiments of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Turning to FIG. 1, there is illustrated therein a carding machine, which may be, for example, an EXACTACARD DK 715, manufactured by Trutzschler G,bH and CO. KG. Monchengladbach, Federal Republic of Germany. The carding machine has a feed roller 1, a feed table 2 cooperating therewith, a licker-in 3, a main carding cylinder 4, a doffer 5, stripping rollers 6, crushing rollers 7 and 8, a fiber web guiding element 9, a sliver trumpet 10, calender rollers 11 and 12 as well as travelling flats 13 cooperating with the carding cylinder 4. 
     The feed roller 1 is radially immovably supported and cooperates with the movably supported feed table 2 which is urged towards the feed roller 1 by means of a spring 15. A generally vertically oriented fiber tuft feed chute 14 has, at its bottom, a curve terminus 14a which ends immediately at the feed roller 1. As a result, as the feed roller 1 rotates, it draws the fiber material 14b directly from the feed chute 14. 
     The movable feed table 2 is connected with a measuring member 16 formed as an inductive path indicator for generating a signal whose magnitute represents the extent of excursion of the feed table 2 from the feed roller 1. Such excursion occurs in response to a variation in the quantities of fiber material passing between the feed roller 1 and the feed table 2. The signals generated by the device 16 and corresponding to the actual thickness value of the fiber lap passing through the roller 1 are applied to a control device 17 which in turn applies signals to a drive motor 18 for rotating the feed roller 1. 
     Turning now to FIG. 2, in the embodiment shown therein, the feed chute 14 is provided, in its lower zone, with air outlet apertures 14c and 14d. The feed roller 1 and a counterroller 19 arranged side-by-side at the discharge end of the feed chute 14. The counterroller 19 is urged against the feed roller 1 in a generally horizontal direction by means of a spring 20. The feed roller 1 cooperates with the counterroller 19 to draw the fiber material from the feed chute 14 and cooperates with the stationary feed table 2 to feed the fiber lap to the licker-in 3. The inductive path sensor 16 emits electric signals as a function of the actual value of the thickness of the fiber lap which passes through the gap defined between the rollers 1 and 19 and the signals are applied to the control device 17 with which there is associated a desired value setter 17a for the desired thickness of the fiber lap. The correcting signals for the rpm&#39;s are applied to the drive motor 18 which is coupled with a device 21 for inputting the basic rpm values for the motor. 
     Turning now to the embodiment illustrated in FIG. 3, the feed table 2 is provided with an opening 2a in which at least one sensor element 22 is accommodated. The sensor element 22 is mounted at one end of a two-arm lever 23 which is rotatably mounted on a support 25 and whose other arm carries a weight 24, by means of which the sensor element 22 is resiliently urged towards the feed roller 1. The inductive path sensor 16 is connected to the lever arm 23a. 
     In the embodiment illustrated in FIG. 4, the feed roller 1 is situated laterally above the counterroller 19, as opposed to the side-by-side arrangement of these components in the two embodiments illustrated in FIGS. 2 and 3. In the FIG. 4 embodiment, the feed table 2 has two adjoining concave recesses 2c and 2d which conform to the convex course of the counterroller 19 and the feed roller 1, respectively. A lower terminal length portion of the feed chute 14 is supported for pivotal motion about a horizontal axis at a bearing support 26 whereby the lower feed chute portion 14e, together with the feed roller 1 and the counterroller 19 can be pivoted away from the feed table 2 into the dash-dotted position indicated at 14&#39;, 1&#39; and 19&#39; in the direction of the arrow A and may be pivoted back into the full line position in the direction of the arrow A&#39;. 
     In the embodiment illustrated in FIG. 5, the feed chute 14 is situated substantially vertically above the licker-in 3. The lower portion of the chute wall 14f is pivotally supported at 26 for movement about the horizontal axis and is biased by a spring 15. The lower end of the feed chute wall 14f is designed as the feed table 2 which cooperates with the feed roller 1. The gap between the feed roller 1 and the feed table 2 extends approximately vertically above the center of the licker-in 3. The short-period regulation in the FIG. 5 embodiment corresponds to that described in connection with FIG. 3. 
     Turning now to the embodiment shown in FIG. 6, there is illustrated therein a dual-chute tuft feeder comprising a lower feed chute 14 and an upper, reverse chute 27 between which there are arranged a slowly rotating supply roller 28 and a rapidly rotating opening roller 30. The control device 17 is electrically connected with the drive motor 18 of the feed roller 1 and with the drive motor 29 of the supply roller 28. Thus, in this arrangement a single measuring member 16 serves two setting members, namely the feed roller 1 cooperating with the licker-in 3 and the supply roller 28 cooperating with the opening roller 30. 
     Arrows drawn into rollers 1, 3-8, 11-12, 19, 28 and 30 indicate directions of rotation. 
     By virtue of the fact that the terminus of the feed chute is situated above the height level of the rotary axis of the licker-in 3 as illustrated in FIGS. 3, 5 and 6, it is feasible to provide, for a given diameter, a greater number of knives and stationary carding devices along the circumferential surface of the licker-in. In case the diameter of the licker-in is reduced, a higher rpm is possible at the same circumferential speed. In this manner, a larger centrifugal force is generated which inproves the separation of trash and other impurities. 
     The present disclosure relates to subject matter container in Federal Republic of Germany Patent Application No. P 37 33 631.2 (filed October 5th, 1987) which is incorporated herein by reference. 
     It will 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.