Abstract:
A fiber processing machine includes a rotatably supported clothed opening roll; a withdrawing roll adjoining the opening roll and supported for rotation for forwarding the fiber material to the opening roll; an optical sensor system for detecting foreign material carried on the opening roll along with fiber material; an air stream generating device for directing an air blast to the clothing of the opening roll; a control-and-regulating device to which the optical sensor system and the air stream generating device are connected for operating the air stream generating device upon detecting foreign material by the optical sensor system to remove and carry away the foreign material from the clothing of the opening roll by an air stream; and a collecting chamber for receiving the air stream carrying the foreign material.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the priority of German Application Nos. 198 06 894.8 filed Feb. 19, 1998 and 198 47 237.4 filed Oct. 14, 1998, which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     This invention relates to an apparatus for removing foreign material from a rapidly rotating fiber opening roll of a fiber processing machine which may form part of a fiber processing line. The clothing of the opening roll is associated with at least one feed roll (also referred to hereafter as withdrawing roll), a cover and an optical sensor system for recognizing foreign material. The optical sensor system is connected with an electric control-and-regulating device which, in turn, is coupled to a device which removes the foreign material and which includes a mechanism for generating an air blast directed to the clothing of the opening roll for dislodging and carrying away the foreign material from the clothing of the opening roll. 
     German Offenlegungsschrift (application published without examination) No. 195 43 526 discloses an apparatus in which two slowly rotating feed rolls laterally cooperate with the opening roll for advancing the fiber material thereto. Guide plates are provided for maintaining the co-rotating air screen on the opening roll. At the lower end of the opening roll a sensor device is disposed for optically recognizing foreign bodies in the fiber tufts. The sensor device is disposed in a collecting chamber for the separated foreign parts. Between the guide plate and a knife an aperture is provided through which, for a short period of time, an air blast is directed from below in an oblique orientation to that region of the roll surface where the fiber tufts contain the foreign bodies. As a result, the contaminated fiber tufts are blown off the roll surface and are subsequently carried away. 
     It is a disadvantage of the above-outlined prior art device that it needs substantial space because of the lateral introduction of the fiber tufts from a laterally arranged accumulator, conveyor or the like and also because of the arrangement of the optical sensor device and the blowing direction of the air-blast generating source in the region underneath the opening roll. It is a particular drawback that the air-blast generating device is situated in the waste collecting chamber which may lead to significant operational disturbances, interruptions and down times. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provide an improved fiber processing machine of the above-outlined type from which the discussed disadvantages are eliminated and which, in particular, is structurally simple and compact. 
     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 rotatably supported clothed opening roll; a withdrawing roll adjoining the opening roll and supported for rotation for forwarding the fiber material to the opening roll; an optical sensor system for detecting foreign material carried on the opening roll along with fiber material; an air stream generating device for directing an air blast to the clothing of the opening roll; a control-and-regulating device to which the optical sensor system and the air stream generating device are connected for operating the air stream generating device upon detecting foreign material by the optical sensor system to remove and carry away the foreign material from the clothing of the opening roll by an air stream; and a collecting chamber for receiving the air stream carrying the foreign material. 
     By virtue of the fact that the air stream is guided into a collecting chamber, the air stream, together with the contaminated fibers (that is, fibers intermingled with the foreign bodies) may be captured and its velocity reduced. Swirling of the air is prevented and, at the same time, the fibers and the foreign bodies are collected. Such a capture occurs in the desired direction and at a suitable location. The provision of such a collecting chamber eliminates a source of danger posed by the powerful air stream. 
     By providing, according to a further feature of the invention, for the fiber material a substantially vertical feed chute, at the lower end of which a withdrawing roll and therebelow an opening roll are disposed, the fiber material is presented to the clothing of the opening roll by the withdrawing roll from above. The withdrawing roll at the same time serves as a feed roll for the opening roll and is disposed adjacent an upper region of the opening roll. Such an arrangement saves horizontal space in the blow room. 
     The invention has the following advantageous additional features: 
     The collecting chamber is situated adjacent the opening roll. 
     The collecting chamber is dimensioned such that the air stream expands therein upon introduction. 
     The compressed air stream generates a suction stream. 
     The suction stream tears away the fibers with the foreign bodies from the opening roll, and has a velocity of, for example, 10-25 m/sec. 
     The compressed air stream is discharged by sectional nozzles. 
     The air stream carrying fibers and foreign bodies from the clothing of the opening roll passes through a channel which opens into the collecting chamber and which is provided with a stream-deflecting member. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic side elevational view of a fiber opening, cleaning and carding line incorporating the invention. 
     FIG. 2 is a schematic top plan view of a fiber processing line similar to FIG. 1 incorporating two apparatuses according to the invention. 
     FIG. 3 is a schematic sectional side elevational view of a preferred embodiment of the invention including a feed chute and an after-connected opening roll as well as foreign material recognition and removal devices. 
     FIG. 4 is a schematic sectional side elevational view of an optical sensor system forming part of the invention and including a camera disposed adjacent a feed chute and oriented toward the opening roll. 
     FIG. 4 a  is a schematic sectional side elevational view of the camera of FIG. 4, illustrated in a position pivoted away from the opening roll. 
     FIG. 5 is a schematic sectional elevational view of a device generating an air blast tangentially to an opening roll and having means for removing the air stream carrying foreign material. 
     FIG. 6 is a schematic side elevational view of an air expansion and waste collecting chamber forming part of the invention. 
     FIG. 6 a  is a schematic side elevational view of an air expansion and waste collecting chamber designed as a removable carriage. 
     FIG. 7 is a schematic sectional side elevational view of a device for separating fiber material from the air stream. 
     FIG. 7 a  is a sectional view taken along line VIIa-VIIa of FIG.  7 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 illustrates a fiber processing line whose first machine is a bale opener  1  which may be a BLENDOMAT BDT model, manufactured by Trützschler GmbH &amp; Co. KG, Monchengladbach, Germany. Between the bale opener  1  and a fiber mixer  5  a high-capacity condenser  2  is arranged which is followed by a feed chute  3  and a fiber transporting fan  4 . The mixer  5  is followed by a further fiber transporting fan  6 , a fiber separator  7 , a feeding device  8  and a multi-roll cleaner  9 . The cleaner  9  is followed by the apparatus  10  according to the invention which, in turn, is adjoined in the downstream direction by at least one card feeder  11  and one carding machine  12  which may be, for example, an EXACTACARD DK model manufactured by Trützschler GmbH &amp; Co. KG. Underneath the bale opener  1  a bale series  1   a  is positioned (only one bale is visible); the bale opener  1  travels over the bale series  1   a  in a direction perpendicular to the plane of drawing FIG. 1 while it removes fiber material from the top of the fiber bales. The above-described machines are serially connected by pneumatic conduits  13 . It is noted that the directions “upstream” and “downstream” are related to the direction in which the fiber material travels through the fiber processing line. 
     Turning to FIG. 2, in the cotton cleaning line shown therein the mixer  5  is followed by a branch-off device  14  whose conduits  13 ′,  13 ″ lead to respective sawtooth cleaners  9 ′,  9 ″, each of which may be a CLEANOMAT CVT model, manufactured by Trützschler GmbH &amp; Co. KG. Downstream of each sawtooth cleaner  9 ′,  9 ″ respective apparatuses  10 ′ and  10 ″ structured according to the invention are connected which, in turn, are followed by card feeders  11 ′,  11 ″ and associated carding machines  12 ′,  12 ″. Upstream of the mixer  5  a dual-roll cleaner  42  is positioned which may be an AXI-FLO model manufactured by Trützschler GmbH &amp; Co. KG. 
     Turning to FIGS. 3,  4  and  5 , a substantially vertical tuft feed chute  15  has, at its lower end, two slowly rotating feed rolls (withdrawing rolls)  16   a  and  16   b  which introduce fiber material to a rapidly rotating opening roll  17  having a clothing  17   a  and a direction of rotation  17   b . The withdrawing rolls  16   a ,  16   b  which rotate in the direction  16   1  and  16   2 , respectively, are situated in the immediate vicinity of the clothing  17   a  of the opening roll  17 . A camera  20 , such as a CCD line camera of an optical sensor system  19  which also includes an electronic evaluating device  21  for recognizing foreign bodies, is directed to the clothing  17   a  of the opening roll  17 . The sensor system  19  recognizes foreign bodies and particles, particularly those which deviate in lightness and color from the fiber material to be processed. The sensor system  19  is connected by means of an electronic control and regulating device  22  with a device  23  for removing the foreign bodies. The device  23  generates a short-duration, powerful air stream (air blast) oriented toward the clothing  17   a  for dislodging and carrying away foreign bodies with a small quantity of fibers from the clothing  17   a.    
     A fiber transporting fan  25  pneumatically introduces fiber material into an upper inlet opening of the feed chute  15 . A stationary, air-pervious surface (screen)  26  arranged at the top of the feed chute  15  separates the fiber material from the air stream which thus exits the feed chute  15 , while the fiber material proceeds toward the withdrawing rolls  16   a ,  16   b . Further in the upper part of the feed chute  15  an air stream guiding device  27  having movable elements is disposed for effecting a back-and-forth agitation of the fiber material at the inner face of the screen  26  as the air stream separates therefrom and passes through the screen  26 . Eventually, the fiber material, substantially by gravity, drops down into the feed chute  15 . The rolls  16   a ,  16   b  have a dual function: they serve as withdrawing rolls for the fiber material by pulling it downwardly in the feed chute  15  and also serve as feed rolls for presenting the fiber material to the opening roll  17 . 
     The solid arrows in FIGS. 3,  5 ,  6 ,  7  and  7   a  illustrate fiber material flow, while the empty arrows indicate air streams without fibers and the half solid, half empty arrows designate fiber-laden air streams. 
     The camera  20  is situated, as shown in FIGS. 3 and 4, obliquely above the opening roll  17  in the vicinity of the outer wall  15   a  of the feed chute  17 , whereby a compact, space-saving construction is obtained. The camera  20  is oriented towards the clothing  17   a  of the opening roll  17  and is capable of recognizing colored foreign material such as red fibers in the fiber flow. The range of the camera  20  includes the full axial length of the opening roll  17  which may be, for example, 1 m. As viewed in the direction of rotation  17   b  of the opening roll  17 , downstream of the optical sensor system  19  the device  23  for generating a pneumatic stream is arranged which has a nozzle  23   a  oriented in the direction of the clothing  17   a  of the opening roll  17  in such a manner that a short-duration, powerful air stream flows to the clothing  17   a , approximately tangentially thereto. The sensor system  19  is coupled via the evaluating device  21  and the electronic control-and-regulating device  22  with the air-blast generating device  23  which includes a valve control device  24 . When the camera  20 , based on comparison values or desired values, detects foreign material in the fiber mass situated on the clothing  17   a , the valve control device  24  sends a command to the device  23  to emit a short, high-speed air blast toward the clothing  17   a  to remove the foreign material from the fiber layer on the clothing  17   a  with a small number of fibers. 
     The sensor system  19  is accommodated in a housing  56  which, as shown in FIG. 4 a , may be pivoted inwardly and outwardly about a stationary rotary support  57 . 
     Turning to FIG. 5, the two withdrawing rolls  16   a  and  16   b  are arranged obliquely above the rotary axis M of the opening roll  17 , adjacent the clothing  17   a  thereof. As viewed in the rotary direction  17   b , downstream of the withdrawing rolls  16   a ,  16   b  a cover  28 , a cover element  29 , an opening  30 , a cover element  31 , an opening  32  and a cover element  33  are arranged in a circumferential series about the opening roll  17 . The device  23  is coupled to a pressurized air source  25 ′. The valve control device  24  opens a non-illustrated valve of the separating device  23  for a short period so that a strong air jet D 1 , with a high speed of, for example, 15-25 m/sec is discharged by the nozzle  23   a  of the separating device  23 . Expediently, a non-illustrated nozzle bank with several linearly arranged nozzles  23   a  is provided which extends over the width (axial length) of the opening roll  17 . The cover  29  and a guide face  34   a  of an oppositely situated guide element  34  are arranged conically with respect to one another and have, at their narrowest clearance, a distance a from one another through which the air stream D 2  passes in such a manner that it flows at a small distance from the clothing  17   a . As a result, a suction stream F 1  is generated (based on the principle of a water jet pump) which, for a short period of time, locally tears away a small quantity of fibers together with the foreign material from the fiber layer carried on the clothing  17   a . The guide element  34  has a rounded nose  34   b  and a further guide face  34   c  which, together with an oppositely disposed deflecting element  35 , forms a channel  36  for guiding the air stream F 2  away from the opening roll  17 . An air stream G flows in the direction of the opening roll  17  through a channel  37  toward the opening  32  for dislodging the fiber layer from the clothing  17   a  and flows through a channel  38  as a fiber-laden stream H. 
     Turning to FIG. 6, laterally of the feed chute  15  and the optical sensor system  19  a receptacle  39  is disposed, having a bottom  39   d  and a side wall  39   a  which is provided with an opening connected to the channel  36 . The fiber-laden air stream F 2  enters the inner chamber  39   e  of the receptacle  39 . The volume of the chamber  39   e  is designed such that the air stream F 2  expands and its velocity significantly drops. The chamber  39   e  at the same time serves as a collecting space for the separated fiber material containing the foreign bodies. The side walls  39   a ,  39   b  and the top wall  39   c  of the receptacle  39  are formed as air-pervious screens to allow the air stream to be separated from the foreign material and to thus exit the receptacle  39 . In the plane of the side wall  39   b  an access door  40  is provided through which the waste collected in the chamber  39   e  may be periodically removed. Between the end of the channel  36  and the opening in the wall  39   a  an air-pervious slidable gate  41  is provided which is displaceable in the direction of the two arrows when the access door  40  is opened or, respectively, closed. Preferably, the receptacle  39  is of upright design, whereby horizontal space may be saved. As shown in FIG. 6 a , the receptacle  39  is part of a wheeled carriage which may be connected to or disconnected and moved away from the channel  36 . The further wall faces of the receptacle  39  oriented perpendicularly to the walls  39   a ,  39   b  are not illustrated. 
     As shown in FIG. 7, the fiber material transporting fan  25  is arranged laterally of the wall  15   b  of the feed chute  15 . The fan  25  blows the fiber-laden air stream A (discharged, for example, by an upstream-arranged machine of the fiber processing line) through the conduit  43  into a chamber  44  in which the stationary, semi-cylindrical, air-pervious screen  26  is provided for separating the fiber material B from the air stream. The air stream C thus stripped of the fiber material (but still containing dust) passes through the screen  26  into the chamber  45  and exits through an outlet  46 . The conduit  43  is adjoined by an air guiding device  27  having movable elements, whereby a reversible, back-and-forth guidance of the material in the air stream may be effected, and the fiber material B, after impinging on the air-pervious surface  26 , drops downwardly essentially by gravity and is introduced into the feed chute  15 . The outlet end of the conveying conduit  43  merges into the chamber  44  approximately tangentially to the screen  26 . During operation, the stream A, after impinging on the screen  26 , sweeps therealong and thus has a cleaning effect thereon. The perforations (meshes) of the screen  26  have a size which is sufficient to allow passage of the dust-laden air stream C and small impurities on the fiber tufts but prevents passage of the fiber tufts B. 
     Turning to FIG. 7 a , the earlier-noted back-and-forth guidance of the fiber-laden air stream A is effected by a pair of oscillating guide plates  27   a ,  27   b  whose surfaces are essentially parallel to one another and are driven, for example, by a motor  47 . The outlet opening of the conduit  43  is situated in the space between the two guide plates  27   a ,  27   b.    
     The invention also encompasses an embodiment in which the feed chute  15  serves as a fiber accumulator in a cleaning line such as shown in FIG.  1 . Expediently, the feed chute  15  has a filling height regulating device including, for example, an optical barrier or the like, and further, the rpm of one or both withdrawing rolls  16   a ,  16   b  may be regulated. Preferably an electronic control-and-regulating device such as a microcomputer  22  is provided to which there are connected the setting member for the rpm of at least one of the feed rolls  16   a ,  16   b  and at least one measuring member sensing the fill level in the after-connected card feeder chutes  11  for the cards  12 . Expediently, at the card feeders  11  electronic pressure switches are used as measuring members, and to the control-and-regulating device  22  an element is connected for determining a basic operating rpm as a function of the sum of all productions of the cards  12 . 
     The invention also encompasses an embodiment in which the optical sensor system  19  is installed in a multi-roll cleaner  9  (FIG. 1) and is associated with a first opening roll, whereas the device  23  for generating the air blast is associated with the last opening roll, as viewed in the direction of fiber travel through the cleaner. 
     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.