Abstract:
A fiber tuft feeding device for a fiber processing machine includes a fiber advancing member; and an extruded, light-metal feed tray defining, with the fiber advancing member, a nip between which the fiber tufts pass in a feed direction. The feed tray which has a length extending transversely to the feed direction, includes an elongated cavity extending along the tray length. An elongated element which is resistant to bending, is received in the cavity and is substantially coextensive therewith. The feeding device further includes a support for positioning the feed tray adjacent the fiber advancing member.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the priority of German Application No. P 44 39 564.7 filed Nov. 5, 1994, which is incorporated herein by reference. 
    
    
     CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the priority of German Application No. P 44 39 564.7 filed Nov. 5, 1994, which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     This invention relates to an apparatus for cleaning and opening fiber material such as cotton, synthetic fiber or the like presented in tuft form. The apparatus includes a fiber tuft feeding device such as a feed roller cooperating with a feed tray and at least one downstream-arranged opening device such as an opening roller with a cleaning device. The fiber material passes through the feeding device and the opening device and is thereafter advanced to a fiber processing machine. 
     According to a prior art arrangement, the feed tray of the feeding device is movably supported for the purpose of effecting a clamping of the fiber material by the feed roller and the feed tray. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provide an improved apparatus of the above outlined type in which the fiber material throughput is improved while maintaining a highly satisfactory clamping effect and which is simple to manufacture. 
     This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the fiber tuft feeding device for a fiber processing machine includes a fiber advancing member; and an extruded, light-metal feed tray defining, with the fiber advancing member, a nip between which the fiber tufts pass in a feed direction. The feed tray which has a length extending transversely to the feed direction, includes an elongated cavity extending along the tray length. An elongated element which is resistant to bending, is received in the cavity and is oriented parallel to the tray length. The feeding device further includes a support for positioning the feed tray adjacent the fiber advancing member. 
     The use of an extruded, light-metal feed tray permits to so design the feed tray surface oriented towards the fiber material that an optimal fiber flow rate is achieved. In particular, the desired feed tray shape is obtained in a simple manner by an extrusion process. By virtue of the fact that the extruded component is associated with an element having a substantial resistance to bending, such as a steel core, flexing of the light-metal (for example, aluminum) feed tray along the machine width is prevented or at least reduced. In this manner the shape of the feed tray and thus the feed gap for the fiber material defined between the feed tray and the feed roller is configured in an optimal manner and, at the same time, the feed tray may be manufactured in a simple manner. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a schematic side elevational view of a three-roller fiber tuft cleaner having a resiliently supported feed tray according to the invention and a stationarily supported feed roller. 
     FIG. 2 is a schematic side elevational view of a preferred embodiment of the invention. 
     FIG. 3 is a sectional view taken along line III--III of FIG. 2. 
     FIG. 4 is a sectional elevational view of some of the components shown in FIG. 3. 
     FIG. 5 is a sectional elevational view of another preferred embodiment of a component of the invention. 
     FIG. 6 is a sectional side elevational view of yet another preferred embodiment of a component of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Turning to FIG. 1, there is illustrated therein a fiber tuft cleaner which may be a CVT model manufactured by Tr utzschler GmbH &amp; Co. KG, M onchengladbach, Germany. The apparatus is disposed in a closed housing and the fiber material B, such as cotton, is introduced in fiber tuft form into the cleaner. Such a material supply is effected by means of a non-illustrated feed chute or a conveyor belt or the like. The fiber mass is advanced to a rapidly rotating pin roller 3 by a feed roller 1 in cooperation with a feed tray 2, whereby a clamping effect is exerted on the material. The pin roll 3 may have a diameter of, for example, 250 mm and is rotatably held in the cleaner housing for a counterclockwise rotation as indicated by the arrow 3b. The pin roll 3 is followed by sawtooth rolls 4 and 5. The sawtooth roll 4 may have a diameter of approximately 250 mm. The pin roll 3 and the sawtooth roll 4 may have a circumferential speed of, for example, 15 m/sec and 20 m/sec, respectively. The circumferential speed of the sawtooth roll 5 is greater than that of the sawtooth roll 4. The diameter of the sawtooth roll 5 is also approximately 250 mm. The pin roll 3 is surrounded by a housing 6 and is associated with a discharge opening 9 for ejecting fiber impurities whose size is adapted to the grade of soiling of the cotton. The waste outlet opening 9 is bordered by a mote knife. 
     The feeding device includes the slowly rotating feed roller 1 rotating in the direction of the arrow 1a and the feed tray 2 situated above the feed roller 1. The feed tray 2 is supported at one end of a lateral extension 2a in a rotary bearing 7. The outer upper feed tray surface 2&#39; is contacted by a compression spring 8 which resiliently loads the feed tray 2. The rotary support for the feed roller 1 is stationary. 
     The above described device operates as follows: the fiber lap B formed of fiber tufts is clamped by the feed roller 1 and the feed tray 2 and is advanced to the pin roll 3 which combs the fiber material and entrains, on its pins, fiber bundles from the fiber lap. As the material, carried in a circular path by the pins of the roll 3 passes by the waste discharge opening and the mote knife 10, dependent upon the circumferential speed and the curvature of the pin roll 3 as well as the size of the waste discharge opening 9, short fibers and coarse impurities are thrown out of the material by centrifugal forces. The fiber material pre-cleaned in this manner is taken over by the points 4a of the sawtooth roll 4 from the pin roll 3 and performs additional opening operations thereon. Thereafter the fiber material is taken over by the points 5a of the sawtooth roll 5 which is located immediately downstream of the roll 4, as viewed in the working direction A. The roll 5 further opens the fiber material and advances it to a pneumatic removal device 11 which transports the fiber material to a non-illustrated further fiber processing machine. 
     The feed tray 2 is an elongated, extruded aluminum component having a cavity which extends along the length of the feed tray, that is, along the width dimension of the cleaning apparatus and accommodates an elongated element, such as a steel bar (steel core) 12 which is resistant to bending and thus prevents undesired flexing of the feed tray along its length. 
     Turning to FIGS. 2 and 3, the steel bar 12 has, at its opposite ends, stepped-down extensions 12a, 12b which have a length b and which serve for supporting the feed tray 3 in the machine frame. FIG. 3 shows such a supporting structure for the extension 12a which passes through an opening 13a in the machine stand 13. The extension 12a is, for example, by a screw 14, secured in a lever arm 15a of a holding element 15 which is pivotal in the direction 18 and 19 in a rotary bearing (such as a ball bearing) 16 about a pivot pin 17 affixed to the machine frame 13 and having a rotary axis which is perpendicular to the direction of fiber feed and parallel to the length dimension of the feed tray 2. Another lever arm 15b of the holding element 15 is engaged by a compression spring 20, against the force of which the feed tray 2 executes excursions in case of a thickness variation of the lap B. The machine frame 13 further carries a stop 21 which determines the minimum clearance between the feed roller 1 and the feed tray 2. As seen in FIGS. 2 and 3 when viewed together, the steel bar 12 is received in the C cavity of the feed tray 2 with a close fit. FIG. 2 further shows that the distance between the cooperating, fiber-engaging surfaces of the feed roller 1 and the feed tray 2 decreases in the direction of fiber feed. 
     Turning to FIG. 4, the feed tray 2 has, along its length, a rectangular, laterally open cavity 2b receiving the steel bar (steel core) 12 of complemental rectangular cross section. Screws 22, 23 secure the steel bar 12 to the feed table 2. A closure element 24 covers the lateral opening of the feed tray 2 and is coupled thereto by a securing attachment 25. The closure element 24 is also secured to the steel core 12 by a screw 26. 
     FIG. 5 illustrates an embodiment where the steel bar (steel core) 30 is a cross-sectionally circular component having a flattened, planar securing surface 31. The feed tray 32 has a cavity shaped complementally with the circumferential outline of the steel core 30. The steel core 30 is tightened to the feed tray 32 by a screw 33. 
     The feed tray 34 according to the embodiment shown in FIG. 6 has a curved surface 2&#34; which is oriented towards the fiber lap B during operation and which is provided with a wear resistant, thin sheet metal member 27 made, for example of high grade steel and is made to conform in a simple manner to the particular configuration of the surface 2&#34; to which it may be secured by gluing. The sheet metal member 27 has smooth surfaces so that a firm connection with the feed tray surface 2&#34; and a low-friction contact with the fiber lap B may be ensured. Instead of providing a sheet metal member, the surface 2&#34; of the feed tray 34 may be made wear-resistant by metal plating, by providing a wear-resistant coating or by surface-hardening. 
     The apparatus according to the invention may find application in a machine which serves only for opening the fiber material, for example chemical fibers or which serves for both the opening and the cleaning of the fiber material, such as cotton. 
     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.