Abstract:
An apparatus for cleaning foreign matter from separated tufts of fiber uses a transfer cylinder intermediate a revolving open reel type structure mounted within a porous housing to separate a conveying air stream from tufts of fiber conveyed thereby and a toothed cleaning cylinder to separate air flow through said revolving reel from said cleaning cylinder such that air is not drawn through said cleaning cylinder into said porous housing.

Description:
[0001]    This application is a continuation in part of and jointly owned by the same assignee as application Ser. No. 12/168,497 filed on Jul. 17, 2008 which claims priority to U.S. provisional application No. 60/950,222, filed Jul. 17, 2007, which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    This invention relates to cotton fiber processing and more particularly to an apparatus and method of separating foreign matter from fibrous cotton that has been ginned from the seed. About 60 years ago cotton “lint Cleaners” were introduced into cotton gins in the United States to overcome the dramatic increase of extraneous matter brought to the gins in the seed cotton harvested by the newly introduced mechanical cotton harvesters as compared to the previously customary hand picked (harvested) cotton. These “Saw-type” lint cleaners did indeed greatly improve the appearance of the lint by removing much “trash”, but also by aggressively “combing” the tufts of fibers to diffuse them and hide the remaining fine trash particles. The most successful of these “Saw Type” lint cleaners contained a “Feed Roller” working against a concave “Feed Plate” to compact the lint batt and firmly hold it about 7 mm from the sharp tips of the fine teeth on the lint cleaner cleaning cylinder that plucked the fibers from the batt. These lint cleaners were commercially very successful because they made the lint appear to the naked eye to meet the higher grades in the classing sample standard grade boxes which were the primary determinant of the lint value along with the manually determined “staple length” which also “pulled” somewhat longer by the manual grading or classing systems of the day. Soon two and even three stages of these aggressive lint cleaners were used in series benefitting the farmers, but the results at the textile spinning mills proved disappointing. 
         [0003]    The inadequacy of the manual-visual method of classing lint cotton became apparent, and innovative researchers introduced various cotton quality test instruments that measured spinning qualities that were only vaguely sensed by manual methods, if detected at all. Several of these test instruments were improved to perform fast enough to process lint samples as they were produced during the peak of the ginning season, and they were combined into a classing system referred to as “High Volume Instrumentation” (HVI). HVI systems were officially adopted for commerce in the United States and today HVI systems are being promoted for use around the world. However, there is much inertia in the long standing manual classing systems and the transition to HVI commercial use in many foreign countries may be very gradual. 
         [0004]    As more of these accurate spinning quality tests were made using instrument testing equipment comparing the before and after lint quality through these saw type lint cleaners, it became clear that these lint cleaners were breaking many fibers and producing neps, both of which are very detrimental to yarn quality. The location within these saw type lint cleaners that caused this fiber quality damage was controversial, but it has now been shown that the major damage is caused at the point where the cotton batt is fed to the teeth of the cleaning cylinder. 
         [0005]    Patent application Ser. No. 12/168,497 describes apparatus that reduces fiber damage by eliminating the formation of the cotton tufts into a batt, but rather, individually applies the tufts of cotton as they come from the gin stand in an air stream directly onto the teeth of the lint cleaner cleaning cylinder teeth without mechanically restraining the tufts. This patent application is for use with lint cleaners that have short, densely spaced teeth on a solid cylinder which currently are universally used in the U.S. saw gins on upland cotton. 
         [0006]    Roller ginning in the United States has been almost entirely confined to ginning pima cotton which is more valuable than upland cottons because of its extra long, fine fibers that warrant the slow, more expensive roller ginning process that also breaks fewer fibers than saw ginning. However, the roller ginning process has recently been made much faster until roller ginning speed (Capacity) is now nearing saw ginning capacity per unit width of ginning machine. High speed roller ginning is now being introduced to the ginning of some upland cottons in response to monetary incentives for roller ginned lint. Roller ginned lint is classed on a different system from saw ginned lint. The roller ginned lint classing system has completely different standards for “preparation”. The roller ginned “prep” standard calls for a certain lumpy appearance caused by the roller gin that pulls off much larger tufts from the seed than saw gins. The lint cleaners used with roller gins, therefore, do not as aggressively “comb” the lint to preserve the characteristic lumpy appearance of roller ginned lint. The cleaning cylinders used on roller ginned cotton generally have less densely spaced teeth or even bars or lugs which would not provide an air seal between the cleaning cylinder and the high speed separator cylinder housing as is required in application Ser. No. 12/168,491. Furthermore, the textile industry, over many years has developed several specialized cotton cleaning cylinders, including “Kirschner” and “Buckley” beaters, which have more open designs that would allow air to be drawn through the cleaning cylinder back into the high speed separator housing if the apparatus of Ser. No. 12/168,497 were used. Moreover, the open design cleaning cylinders often are self doffing and therefore they eliminate the doffing cylinder of &#39;497, a considerable initial and maintenance expense. The principle proven benefits of Ser. No. 12/168,497 would be lost for use with these many “open” cleaning cylinders without the added concepts of the present invention. 
         [0007]    Other prior methods and apparatus include those such as illustrated in U.S. Pat. No. 6,088,881, incorporated herein by reference, wherein a revolving perforated drum is used to allow air flow through the drum such that a cleaning cylinder may remove cotton fiber from the perforated drum and carry it past a plurality of cleaning grid bars, thereby separating the air flow and removing foreign matter from the fibers, before the fiber is doffed from the cleaning cylinder for subsequent air flow to downstream processing. 
         [0008]    However, the perforated revolving cylinder of the &#39;881 apparatus, revolving at velocities to prevent agglomeration of the tufts in the air stream, develops centrifugal forces that cause the fine trash and very short fibers that penetrate the perforations to accumulate on the interior surfaces of the perforated cylinder. These accumulations require the use of compressed air blasts to cause them to move axially out the open ends of the cylinder. While the compressed air blasts provide a solution to this problem of accumulations, the maintenance and cost of the compressed air system detracts from the otherwise excellent performance of the apparatus per the &#39;881 patent. 
         [0009]    The quality preserving actions of the methods and apparatus shown in U.S. Pat. No. 6,088,881 and application Ser. No. 12/168,497 would be beneficial for use with all types of lint cleaning cylinders, including those used with roller gins. The improvement described herein provides the solution to combining the benefits of these concepts with cleaning cylinders of most all designs. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    An apparatus embodying features of the invention is depicted in the accompanying drawing wherein: 
           [0011]      FIG. 1  is a sectional view of the apparatus disclosed in the copending patent application Ser. No. 12/168,497; 
           [0012]      FIG. 2  is a sectional side elevational view of an embodiment of an apparatus of the present apparatus; 
           [0013]      FIG. 3  is a partial sectional side elevational view of another embodiment of the transfer wheel of the present apparatus. 
       
    
    
     BRIEF SUMMARY OF THE INVENTION 
       [0014]    It is an object of the present invention to provide an improved method and apparatus for separating foreign matter from tufts of fibrous cotton. A further object of the invention is to allow the high speed separation and cleaning of upland cotton using open cleaning apparatus and a combination air seal with fiber transfer roller. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    As shown in  FIG. 1 . Patent application Ser. No. 12/168,497 depends upon the short, dense teeth of the standard cleaning cylinders used in upland cotton gin lint cleaners to seal against the air partial vacuum in the housing surrounding the “high speed air separator cylinder”. This vacuum is required to induce an air stream to convey the tufts of lint to the lint cleaner.  FIG. 1  taken from patent application &#39;497 illustrates the housing around the sub atmospheric air stream entering at C and exiting at E. It also shows the air seal formed between the short, dense teeth at “ 13 ” and close fitting plate “ 27 ” preventing atmospheric pressure air from the trash removing grid area “ 23 ” being drawn into the incoming air stream C. Plate  28  also fits closely to the tips of the cleaning cylinder teeth to prevent air, coming in at D, from being drawn into the housing around the high speed air separator cylinder. 
         [0016]    An improved apparatus and method according to the present invention is illustrated in  FIG. 2 , wherein fiber tufts comingled with foreign matter are pneumatically carried by a conveying air stream C into the apparatus via an air duct  11  as is well known in the art.  FIG. 2  is a cross sectional illustration of a preferred embodiment containing most of the features of the present invention. Fiber tufts, commingled with foreign matter, are conveyed into the entry duct  11  of the apparatus by a high speed air stream preferably under sub atmospheric air pressure. Entry duct  11  converges arcuately toward the periphery of high speed air separator cylinder  17  that is pervious to both inward and outward flow of fiber, foreign matter and air. However, the arcuate convergence of duct  11  combined with the high speed arcuate change of direction develops centrifugal forces urging the fiber and foreign matter to move toward the converging surface  14  of duct  11 . Approximately diametrically opposite the point on the separator cylinder where the duct  11  converges against the periphery of the air separator cylinder  17  is a stationary arcuate section of perforated screen  16  closely following the arc of the periphery of separator cylinder  17 . The perforated screen  16  is pervious to air flow there through, but impervious to desirable fiber. Any fiber that collects on the screen is immediately swept away from the screen by a plurality of circumferentially spaced outer surfaces  18  that are spaced apart circumferentially to allow the conveying air and entrained dust and fine foreign matter particles to pass through the screen  16  and exit the apparatus via an air discharge duct  15  at Q. As outer surfaces  18  rotate across perforated surface  16  the surfaces  18  substantially sweep away any accumulations of matter on the stationary separator surface  16  and return any desirable fiber back to the conveying air stream proximal terminal portion  14  of duct  11 . The rotation of revolving outer surfaces  18  is such that the commingled fiber and foreign matter are exposed to the surface  32  of air seal and fiber transfer cylinder  31  while the revolving outer surfaces  18  are rotating toward stationary semi cylindrical surface  16 . 
         [0017]    Up to this point the present invention follows the teachings of patent application Ser. No. 12/168,497 and the preferred embodiment of the present invention likewise follows  FIG. 1  of patent application Ser. No. 12/168,497. But from this point on the preferred embodiment of the present invention deviates from patent application Ser. No. 12/168,497 in that it calls for the addition of the air seal and fiber transfer cylinder  31  between the air separator cylinder  17  and the cleaning cylinder  12  as shown in  FIG. 2 . As will be understood from the prior art, the rotation of cleaning cylinder  12  carries the tufts past a stripping bar and plurality of cleaning grid bars  23  disposed to separate a major portion of foreign matter from the cotton tufts on the cleaning cylinder  12 , which foreign matter may be disposed via a trash conveyor system for subsequent collection and baling. As noted above, roller ginning is generally used for the higher quality cottons and the lint cleaning machinery often uses longer, more widely spaced pin or lug type cylinders which would not prevent air flow back into the high speed separator section that is under sub atmospheric air pressure. 
         [0018]    Air seal and fiber transfer cylinder  31  is needed for use with such a cleaning cylinder  12  that has longer, less dense teeth or lugs that would allow air to be pulled back from the trash removing grid section into the sub atmosphere air pressure housing around the high speed air separator cylinder  17 . In the present apparatus, as shown in  FIG. 2 , cylinders  17 ,  31 , and  12 , all revolve counter clockwise and preferably successively at increasing surface speeds. Air seal and fiber transfer cylinder  31  primarily acts as what is generally known as a “vacuum wheel”. To make this air seal, air seal and fiber transfer cylinder  31  must fit tightly against arcuate walls  37  and  36  both on the fiber carrying side and the return side of the cylinder  31  and it must be constructed to prevent air from passing through the air pressure differential across the cylinder at all times in its rotation. Also this cylinder  31  must be capable of carrying the fibers around the arcuate fiber transfer side, preferably while holding the fiber tufts firmly in place as they enter the pinch point between this cylinder and the arcuate wall  37  on the fiber carrying side and hold the tufts until they are released to the tip of a streamer plate  38  at the end of the arcuate wall from which the fibers are pulled by the teeth of cleaning cylinder  12 . Thus, in one embodiment, the surface  32  of air seal and transfer cylinder  31  is of a dense brush type consistency that will engage fibers and present a dense but flexible seal in the interstice between the cylinder  31  and the walls  36  and  37 . Such a brush like surface would preferentially be composed of bristles spaced less than about 6 millimeters apart over the surface of the transfer cylinder. 
         [0019]    The surface of cylinder  31  should preferably be radially flexible and continuous to maintain an air seal at all times both on the lower, fiber exit side and upper return side of cylinder  31  running against stationary arcuate sealing surfaces  36  and  37  that join to the housing around separator cylinder  17 . As noted preferred outer surface for cylinder  31  is composed of continuous, dense brush bristles that entrap the fiber tufts against arcuate surface  36  and an adjustable streamer plate  38  which has an acute angle fiber delivery tip to uniformly “payout” the fiber tufts to the teeth of the faster moving surface of cleaning cylinder  12 . That is to say, streamer plate  38  converges to a tip or edge at the interstice of cylinders  31  and  12  with the converging sides being substantially tangent to the adjacent cylinders. Streamer plate is mounted such that it can be mechanically adjusted as is well known in the industry relative to the transfer cylinder  31  and the cleaning cylinder  12 , such that fiber tufts being carried past sealing surface  36  is exposed at the tip or edge of streamer plate  38  to the teeth  13  of cleaner cylinder  12 , such that the fibers may be removed from transfer cylinder  31  for processing by cleaning cylinder  12 . By way of example, streamer plate  38  may be adjusted by appropriate shims or by incorporating an adjustment slot and selectively tightened bolts to allow the plate to vary in inclination and projection. 
         [0020]    It should also be noted that cylinder  31  may be in the form of an air wheel having a solid cylindrical core  41  and a plurality of angularly spaced radially extending flights  42  or brushes which resiliently engage walls  36  and  37  as shown in  FIG. 3 . The flights  42  would be angularly spaced at distances less than the arc defined by wall  36  or  37  such that at least one flight  42  would be in sealing engagement with wall  36  and another in sealing engagement with wall  37  at all times, thereby preventing the flow of air past cylinder  31 . Flights  42  would be sufficiently resilient to carry the fiber tufts past wall  36  to where the fibers would be engaged by cleaning cylinder  12 . The flights  42  may be brushes, belts or other strip like material. 
         [0021]    As will also appreciated, a rotating doffing cylinder or brush  24  can remove the cleaned tufts from the teeth  13  of cleaning cylinder  12  and deliver the cleaned fibers to duct  26 .  FIG. 2  also shows a form of air flow doffing without a doffing cylinder often used with the more open cleaning cylinders. As may be seen the doffing airstream through inlet duct  41  and outlet duct  42  moves in conjunction with the rotating teeth or lugs of cylinder  12  such that fibers are readily entrained in the airflow. The present invention makes air doffing without a doffing cylinder usable with the proven advantages of the high speed separator taught in application Ser. No. 12/168,497. 
         [0022]    While the forgoing specification describes only a few embodiments of the present invention, the invention is not so limited and is intended to encompass the full scope of the claims appended hereto.