Abstract:
A device for sizing a sample of a fibrous substance including a first compression chamber with a first longitudinal axis, a first ram disposed in the first compression chamber, a second compression chamber disposed adjacent the first compression chamber, including a second longitudinal axis that is transverse to the first longitudinal axis, the second compression chamber being configured such that a front surface of the first ram forms a portion of the second compression chamber, a second ram disposed in the second compression chamber with a first cross-section that is complimentary to a cross-section of the second compression chamber, an extrusion nozzle adjacent the second compression chamber, wherein the sample is produced by causing a first compression stage in the first compression chamber.

Description:
CLAIM OF PRIORITY  
       [0001]     This application claims priority to U.S. Provisional Application 60/773,957 filed Feb. 16, 2006, entitled “Sample Sizer for Cotton Bales,” the entire disclosure of which is incorporated by reference herein. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to a device for providing compact samples of a fibrous substance. More particularly, the present invention relates to a device for providing compact samples of cotton so that the samples can be readily stored and require a minimal amount of storage space.  
       BACKGROUND OF THE INVENTION  
       [0003]     Typically, when baling cotton, samples of the lot of cotton from which the bales are being produced are kept in bags and stored for later use. For example, a perspective purchaser may utilize the samples to test the cotton being purchased for various qualities without having to test the individual bales since the cotton in the samples is representative of the baled cotton. As such, testing the cotton is facilitated in that the samples are more readily accessible and more easily handled than is the baled cotton. As well, testing the samples rather than the bales insures the integrity of any protective packaging in which the bales are stored remains intact. However, since cotton is a relatively fibrous substance and an adequate amount for testing must be retained in each sample, the sizes of the samples often require more storage space up until they are used than is desirable.  
       SUMMARY OF THE INVENTION  
       [0004]     The present invention recognizes and addresses consideration of prior art constructions and methods. In one embodiment of the present invention, a device for sizing a sample of a fibrous substance includes a first compression chamber defined by a front wall, a rear wall that is parallel to the front wall, and a first and a second side wall. The first and the second side walls are transverse to the front and the rear walls such that the first compression chamber has a rectangular cross-section about a first longitudinal axis extending between a first end and a second end of the first compression chamber. A first ram is disposed at the first end of the first compression chamber and has a front surface facing the second end of the first compression chamber and is movable along the first longitudinal axis. A second compression chamber is disposed at the second end of the first compression chamber. The second compression chamber includes a second longitudinal axis that extends from a first end to a second end of the second compression chamber and is transverse to the first longitudinal axis. The second compression chamber is configured such that the front surface of the first ram forms a portion of the second compression chamber when the first ram is disposed at the second end of the first compression chamber. A second ram is disposed at the first end of the second compression chamber and has a first cross-section relative to the second longitudinal axis that is complimentary to a cross-section of the second compression chamber relative to the second longitudinal axis. An extrusion nozzle has a first end and a second end and the first end is adjacent the second end of the second compression chamber. The second end of the extrusion nozzle has a cross-section that is smaller than a cross-section of the first end of the extrusion nozzle. The sample is produced by causing the fibrous material to undergo a first compression stage in the first compression chamber and a second compression stage in the second compression chamber, the sample passing out of the device through the extrusion nozzle.  
         [0005]     Another embodiment of the present invention includes a device for sizing a sample of a fibrous substance, including a first compression chamber defined by a front wall, a rear wall that is parallel to the front wall, and a first and a second side wall, the first and the second side walls being transverse to the front and the rear walls. A first ram is disposed at a first end of the first compression chamber and has a front surface facing a second end of the first compression chamber and is movable along a first longitudinal axis of the first compression chamber. A second compression chamber is disposed at the second end of the first compression chamber and includes a second longitudinal axis extending from a first end to a second end of the second compression chamber, the second longitudinal axis being transverse to the first longitudinal axis. A second ram is disposed at the first end of the second compression chamber and includes an unlocking piston of a first cross-section and a piston rod having a second cross-section. The unlocking piston is releasably secured to the piston rod and the first cross-section of the unlocking piston is complimentary to a cross-section of the second compression chamber. The sample is produced by causing the fibrous material to undergo a first compression stage in the first compression chamber and a second compression stage in the second compression chamber.  
         [0006]     The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the invention and, together with the description, serve to explain the principles of the invention.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended drawings, in which:  
         [0008]      FIG. 1  is a perspective view of an embodiment of a sample sizer for cotton according to the present invention;  
         [0009]      FIG. 2  is a front view of the sample sizer for cotton as shown in  FIG. 1 ;  
         [0010]      FIG. 3  is a side view of the sample sizer for cotton as shown in  FIG. 1 ;  
         [0011]      FIG. 4  is a top view of the sample sizer for cotton as shown in  FIG. 1 ;  
         [0012]      FIGS. 5A through 5F  are partial, cross-sectional views of the sample sizer for cotton performing the sequence of events in which a cotton sample is produced;  
         [0013]      FIGS. 6A and 6B  are a front view and a partial side cross-sectional view, respectively, of a piston assembly in accordance with the present invention; and  
         [0014]      FIGS. 7A and 7B  are a top view and a side view, respectively, of an extrusion nozzle in accordance with the present invention. 
     
    
       [0015]     Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention according to the disclosure.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0016]     Reference will now be made in detail to presently preferred embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation, not limitation, of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope and spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.  
         [0017]     Referring now to the figures, in a preferred embodiment, the cotton bale sample sizer  10  includes a rectangular vertical first compression chamber  12 , a first ram  14 , and a side loading door  16  for loading the sample into first compression chamber  12 . On top of the first compression chamber  12  and at a right angle to it is a round horizontal second compression chamber  18  and second ram  20  that compresses the sample into and through a round tapered extrusion nozzle  22  for the purpose of increasing the density and thereby reducing the volume of the sample. A control panel  11  is provided for localized control of the sample sizer  10  by the user.  
         [0018]     The first compression ram  14  performs a single vertical reduction ( FIG. 5B ). The second compression ram  20  performs a two-stage reduction process. A circular unlocking piston  24  ( FIGS. 6A and 6B ) that is attached around a piston rod  26  of the second compression air cylinder performs the first reduction stage ( FIG. 5C ). Unlocking piston  24  is designed to unlock itself from piston rod  26  when compression reaches a predetermined force. This allows unlocking piston  24  to perform the first reduction stage of the second compression, thereby densifying the fiber to a near solid form. Tapered extrusion nozzle  22  is fixed to the exit end of the circular second compression chamber  18  and acts as a wedge choking the opening, thereby increasing frictional resistance. Axial and radial compressions occur simultaneously eliminating the need for an end door. Other embodiments can include a second compression chamber  18  having various cross-sections (i.e. square, polygonally shaped, etc.) and correspondingly shaped second compression ram  20 .  
         [0019]     When the unlocking piston  24  disengages from the piston rod  26 , the air cylinder piston rod  26  is allowed to slide through the unlocking piston  24  ( FIGS. 5D and 5E ). Piston rod  26  pushes the compressed sample through extrusion nozzle  22  and exit pipe  28  and into a small polyethylene sample bag  30  that has been pre-positioned over the outside of exit pipe  28 . In order to prevent piston rod  26  from becoming “wedged” in either the extrusion nozzle  22  or exit pipe  28 , piston rod  26  of the air cylinder has a smaller cross-section than both extrusion nozzle  22  and exit pipe  28 . Rather than becoming wedged, cotton can fold around the end of the piston rod  26 . Wedge prevention allows lower force to be utilized, hence, the cost of production may be lower than other alternatives.  
         [0020]     After the sample is completely ejected, the second compression ram  20  retracts and the unlocking piston  24  is locked back onto the piston rod  26  as the second compression ram  20  returns to its home position and bottoms out. A gap  50  is provided between second ram  20  and second compression chamber  18  so that any cotton that gets trapped behind unlocking piston  24  when it is returned to its initial starting position can be readily removed. The first compression ram  14  then retracts to the full down position. Side loading door  16  can now be opened (as shown in  FIG. 3 ) for the next sample. By mechanical design, side loading door  16  can only be opened when first compression ram  14  is fully retracted. This is a safety feature that prevents operation of first compression ram  14  unless side loading door  16  is closed. An electrical switch is also provided to assure that loading door  16  is closed and latched safely before motion can occur.  
         [0021]     As best seen in  FIG. 4 , an external back pressure device  32  is provided at the end of the pipe  28  to prevent axial expansion of the sample during the extrusion process. An adjustable hydraulic damper  34  provides the correct amount of back pressure to control extrusion. An end stop  36  is attached to hydraulic damper  34  which allows for bagged sample removal and can be tilted out of the way as needed, as shown in  FIG. 3 . A sample tube  39  extends outwardly from end stop  36 . Sample tube  39  is configured to be positioned over exit tube  28  and, therefore, contain the sample as it exits the tube. A spring  38  is provided to retract damper  34  after the sample is removed, which prepositions the end stop  36  for the next sample as shown in  FIG. 5A .  
         [0022]     As best seen in  FIGS. 7A and 7B , a tag holder  40  is located on top of the exit pipe  28  such that the sample bag  30  can be placed over it. Tag holder  40  includes a hook end  53  that is received in a slot  54  and a catch  56  that acts as a trigger for releasing tag  52  as the sample passes through exit pipe  28 . As best seen in  FIG. 7B , as the lead end of the sample engages catch  56 , tag holder  40  is urged upwardly so that tag  52  is no longer retained between tag holder  40  and the outer surface of exit pipe  28 . As the sample exits the pipe, tag  52  is frictionally retained between the sample and sample bag  30 , and thereby removed from exit pipe  28 . The end of the exit pipe  28  is cut with a double 30-degree angle to control radial expansion, thereby reducing sudden bulging resulting in big-ended samples. The double angle aids in sample bag  30  placement and directs expansion favorably such that tag  52  is stripped from holder  40  during extrusion. In the preferred embodiment shown, as the sample is extracted from nozzle  22  and exit pipe  28 , it is received in sample tube  39 , which is pushed outwardly from the sample sizer by the sample. Once the sample is within sample tube  39 , the tube is pivoted out of the way of exit tube  28  for sample removal. The worker will then twist the open end of the polyethylene bag to prevent axial expansion and will then use a tape machine commonly used in gins to seal the sample off. With end stop  36  pivoted out of the way, the next bale sample tag can be inserted under holder  40  ( FIGS. 7A and 7B ) and a new polyethylene sample bag  30  can be pre-positioned over exit pipe  28  and the tag. End stop  36  can now be rotated back into position for the next sample, and as external spring  38  returns end stop  36  back into position, sample tube  39  will receive exit tube  28  and the associated sample bag  30 .  
         [0023]     In another embodiment in which there is no sample tube  39 , as the sample is extruded from the nozzle, the worker can safely place one hand over the sample bag  30  and sample to remove sample from machine. It may be necessary to pivot the end stop  36  out of the way for efficient sample removal. Once the sample is removed, end stop  36  will be returned to the starting position by external spring  38 .  
         [0024]     Referring now to  FIGS. 6A and 6B , preferably, unlocking piston  24  has five radial chambers  42  which contain spring  44  loaded steel balls  46  with an adjustable set screw  48  to provide force adjustment. Balls  46  are seated into a V-shaped notch  50  located around the second compression cylinder piston rod  26 . Balls  46  disengage the notch  50  at a preset axial force, hence, unloading piston  24  is unlocked allowing cylinder piston rod  26  to continue pushing sample through the smaller opening in extrusion nozzle  22  and exit pipe  28 .  
         [0025]     As best seen in  FIG. 6B , the face  25  of unlocking piston  24  is preferably cupped. This has been found to reduce required operating forces during compression of the sample. As well, front face  29  of piston rod  26  is preferably serrated, or toothed, such that portions of the sample are less likely to wrap around piston rod  26  during the compression stage after unlocking piston  24  has been released.  
         [0026]     While one or more preferred embodiments of the invention are described above, it should be appreciated by those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope and spirit thereof. It is intended that the present invention cover such modifications and variations as come within the scope and spirit of the appended claims and their equivalents.