Abstract:
A saw type gin stand for separating cotton lint from seed cotton in which the improvement comprises one or more of the inwardly facing surfaces of the roll box being movably adapted to re-shape the roll box. Specifically the inner surface of the roll box door member and a seed roll retaining member are adjustable during operation of the gin to re-shape the shape of the gin to optimize performance and, when the breast is opened, to retain the seed roll within the roll box and prevent pieces of the seed roll from breaking off of the roll.

Description:
FIELD OF THE INVENTION 
     This invention relates to a novel gin saw stand for ginning seed cotton. In particular, this invention relates to a gin saw stand having a powered roll box door and an adjustable seed roll retaining member that allow for adjustment of the shape of the roll box during operation of the gin saw stand and for automatic extension to retain the seed roll when the breast is opened. 
     BACKGROUND OF THE INVENTION 
     The process of picking cotton and removing seeds, trash and other foreign materials from the seed cotton is well known. Freshly picked seed cotton is transported from the field to a cotton gin. The cotton gin has apparatus for receiving the seed cotton, removing the seeds from the long cotton fiber or lint, cleaning the lint, and pressing the lint into bales for sale and further processing. 
     Central to this process is a saw type gin stand (referred to herein as a gin saw stand or gin). The gin saw stand separates the cotton fiber from the seeds. Before the seed cotton is fed into the gin saw stand, it is processed with other apparatus to remove heavier foreign materials such as rocks and larger sticks, etc., and dried to desired moisture levels. After drying and cleaning, the seed cotton is fed at a controlled rate into a gin saw stand. From the gin saw stand, the cotton fiber is next transported to lint cleaners for further cleaning or processing before bailing. 
     A commercial gin saw stand which is currently in use is shown in cross section in  FIG. 1 . Referring to the figure, conventional gin saw stands  10  typically comprise an inlet cotton chute  11  wherein the cotton is deposited. A gin saw cylinder  12 , composed of a large number of spaced apart circular blades  13  rotating having serrated outer edges  15  about a common axis  14 , is combined with operably associated ribs  26  positioned between the blades  13  of the saw in order to strip the lint from the seed. 
     Delivery of the seed cotton into contact with the teeth of the first saw is assisted by a rotating toothed cylinder, referred to as the picker roller  21 , which throws the cotton from the inlet cotton chute  11  onto the saw  12 . This picker roller  21  is generally positioned with its axis  22  approximately lateral to the axis  14  of the saw  12 , with its outer periphery  23  spaced apart from the serrated outer periphery  15  or teeth of the saw  12 . The locks of cotton are drawn upwardly by the saw  12 , through a passage called the seed discharge shaft  31  and into the lower portion of a roll box  25  positioned above the axis  14  of the saw  12  where the seeds with attached cotton accumulate in a large mass. This mass of seeds and/or seed cotton is commonly referred to as the roll or seed roll (not shown in  FIG. 1 ). Most of the interior of the seed roll is made up of lint-free seed, and the exterior primarily comprises partially ginned seed and un-ginned seed. 
     The roll box  25  is typically of somewhat distorted cylindrical configuration and its structure is shaped by the exposed, inwardly facing (relative to the roll box) surfaces of a plurality of different members of the gin saw stand  10 , such as, in the illustrated example, the upper portions  26   a  of the ginning ribs  26 , the upper rib support  34 , one or more upper gin-side sheet members  38  (which may further comprise the inner surface  37  of door member  36 ), one or more concave partition or sheet members  39  of the breast  18  and adjustable sheet member  20 . Prior art gin saw stands  10  did employ an adjustable sheet member  20  though previously such sheet members have had a very limited degree of actuation, limited to the function and path of travel as that obtained with the cam shaft assembly as discussed herein. Prior art sheet members  20  did not serve the function of retaining the seed roll with in the roll box as is accomplished by the greater range of motion of the seed roll retaining member of the present invention (discussed below). 
     In some prior art gin saw stands (not shown), the roll box may also comprise an alternate additional set of ginning ribs for one or more additional saw cylinders. 
     While the roll box door member  36  of some prior art gin saw stands  10  do not form part of the roll box  25 , it is not uncommon for at least a portion of the roll box  25  to be formed by the concave inner surface  37  of the roll box door member  36  as illustrated in  FIG. 1 . Typically there is a gap or space  35  in the upper portion of the roll box  25  to allow the seed roll to be viewed or even touched as the gin is operating. It will be noted that at the gap  35 , the seed roll will maintain its generally circular shape because the centrifugal force will tend for it to move horizontally at this point, but gravity and the cohesive qualities of the fibers within the exterior regions of the seed roll tends to pull it down. 
     As gin saw capacities have increased, gin saw stands have become wider. At the same time, the increased capacities and density of the seed rolls within these larger machines have resulted in the need for the reinforcement of the roll box surfaces shaping the seed roll. As a result, the surfaces forming the roll box, including the roll box door member  36 , have been made sturdier and more rigid, and thus thicker and heavier. This has resulted in roll box doors  36  that are cumbersome and may require the efforts of two or more individuals to open. 
     The actual separation of the seed from lint takes place in the roll box  25  of the gin saw stand  10 . In the prior art gin saw stand  10  illustrated in  FIG. 1 , a set of ribs, referred to as the ginning ribs  26 , are located in the spaces between the blades  13  of the saw  12  at the downstream end of the roll box  25 , and extend from a position above the periphery  15  of the saw  12  downward through the spaces between the blades  13  to near or below the bottom of the saw  12 . Cotton fibers in the roll box  25  are caught by the teeth of the first saw and passed toward the ginning ribs  26 . As the teeth of the saw  12  pass between the ginning ribs  26 , they pull the lint from the seeds, which are too large to pass between adjacent ribs  26 . The seed-free lint proceeds past the ginning ribs  26  where it is removed from the teeth of the blades  13  by the faster moving brushes of the doffing brush  27  and passed out of the gin stand  10  through the doffing outlet  29  for transferral to the lint cotton cleaners and/or the battery condenser and bailing press depending upon the design of the installation. 
     As the seeds in the seed roll become substantially free of lint or in a substantially completely “ginned” state, they are of appropriate size and character to pass gravitationally downward adjacent the ginning ribs  26  between the saw blades  13  through the seed discharge shaft  31  and into a seed collection area  32  in the front lower portion of the gin saw stand  10 , to be picked up by the usual seed discharge screw conveyor  33  and delivered to the discharge point (not shown). Lint-free seeds are not held firmly within the surface of the seed roll and often escape the seed roll along the relatively sharp curve or bulge in the seed roll that is formed at the bottom of the seed roll over the seed discharge shaft  31  immediately prior to being pulled upward by the periphery  15  of the saw  12 . The seed discharge shaft  31  is defined by the space between the ginning ribs  26  and the closest, lower breast-side edge  45  of the roll box  25 . Note, however, that when the breast  18  is in the closed position, the blades  13  extend through the ginning ribs  26  and into the seed discharge shaft  31 . 
     In contrast to the substantially lint-free seeds, seeds which retain cotton fibers thereon generally remain on the surface of the mass of seeds and seed cotton (the seed roll) in the roll box  25 , awaiting to be caught by the saw  12  and repeat the ginning operation. 
     In some models of gin saw stands, one or more rotating agitators  75  transversely spanning the gin saw stand  10  substantially parallel to the axis  14  of the saw  12  and having a serrated outer edge or periphery  76 , have been placed in the roll box  25  to assist the gin saw  12  in turning the roll of material within the roll box  25 . Typically, such agitators  75  comprise a plurality of discs  77  about the agitator axis  78 , said discs  77  having serrated teeth about the periphery  76  and being canted at an angle relative to the gin saw blades  13  to cause some side to side action within the seed roll. The agitator  75  spins in a direction counter to the direction of the spinning saw  12 . The agitator  75  is typically not located in the exact center of the roll box cavity  25 , but is somewhat offset, and its periphery  76  is closer to the periphery  15  of the saw  12  than to the other surfaces defining the roll box  25 . In some designs (not shown in  FIG. 1 ), the agitator axis  78  further comprises or may be replaced by a perforated tube containing an auger which provides an additional path for seed to leave the seed roll. 
     The gin stand  10  typically comprises a casing or housing comprising a main gin frame  17  supporting the gin saw cylinder  12  and doffing brush  27 , and a separable front, forwardly movable breast  18  including inlet cotton chute  11  and the supports for ginning ribs  26 , picker roller  21 , roll box door member  36 , and (if any) agitator  75 , permitting the breast structure  18  to be drawn away from the main gin frame  17 . The breast  18  is typically attached to the main gin frame  17  in such a manner that it may be pulled away from the frame  17 . In the prior art gin saw stand  10  shown in  FIG. 1 , the breast  18  is moved away from the frame  17  substantially laterally along the surface of an integrated rail or track  49  on opposing sides of the frame  17  by powered gears or a pneumatic cylinder (not shown in  FIG. 1 ) or other common means. Another typical configuration is shown in  FIG. 2  wherein the breast  18  is attached to the frame  17  at a pivot point  19  located near the front bottom of the main gin frame  17  so that the breast  18  may be tilted away from the main gin frame  17 , thereby creating greater space between the breast  18  and the main gin frame  17  at the top of the breast  18  than at the lower regions. The breast  18  is typically attached to the main gin frame  17  at the top by a pneumatic or hydraulic cylinder  47  to power the movement of the breast between a fully-open, non-ginning position and closed, ginning position. 
     Moving or tilting the breast  18  or otherwise withdrawing it from the main gin frame  17  may be used as a method of interrupting the ginning process instead of stopping the saw  12  from turning. As the breast  18  is withdrawn to a fully-open position, the ginning ribs  26  move even with, or preferably beyond or outside the periphery  15  of the saw  12 , thereby preventing the saw cylinder  12  from removing lint from the seed roll  25 . This is important because it is much more efficient to simply move the breast  18  away from the main gin frame  17  than to stop the relatively massive saw cylinder  12  from spinning, then having to bring it back up to speed when the ginning process is to be re-started. As a practical matter, it is impossible to restart a motionless saw  12  with a full seed roll if the breast  18  is in the ginning position. The saws will encounter so much resistance, that the motor cannot start without over loading the motor starter. 
     Over the years, the capacities of gin saws  12  have increased, with the stands becoming wider and wider and with higher density seed rolls. As capacities have increased, the width of the seed discharge shaft  31  between the ginning ribs  26  and the lower, breast-side edge  45  of the roll box  25  immediately above the picker roller  21  has also increased to allow more cotton into the roll box and more ginned seed out. A drawback to this approach is that when the breast  18  is moved away from the main gin frame  17 , an relatively larger open gap is created between the lower, breast-side edge  45  of the roll box  25  and the ginning ribs  26  as the blades  13  of the saw  12  are withdrawn from between the ginning ribs  26 . When in operation, this gap is occupied by the portion of the saw blades  13  that extends through the ginning ribs  26  and the spin of the saw blades  13  provides an upward current in the mass of seeds and seed cotton in the roll box such that there is little likelihood that seed cotton will fall down the seed discharge shaft  31 . However, as progressive models of saw stands have moved the lower, breast-side edge  45  of the roll box  25  higher and higher above the picker roller  21  to allow for greater cotton flow, the width of the open gap created when the breast  18  is opened has also increased because as seen in  FIG. 1 , the ginning ribs  26  typically have a curvature that mirrors an arc of the periphery  15  of the circular saw blades  13 . Therefore, the higher the bottom edge  45  of the seed box  25  is positioned relative to the periphery  15  of the saw  12 , the further the ginning ribs  26  curve away from the bottom edge  45  at that same relative height. 
     The larger gaps created when the breast  18  is opened combined with the bigger and more dense seed rolls in current gin saw stands, has led to an increase in the occurrence of seed roll breakage, with parts of the roll, and sometimes even the entire seed roll, including un-ginned seeds with usable cotton, breaking off and falling into the seed discharge shaft  31  when the breast  18  is opened because it is no longer supported by the saw  12  or the lower edge  45  of roll box  25  and/or seed vanes  40  (if any). Obviously, the loss of un-ginned cotton down the seed discharge shaft  31  is undesirable in that it is either wasted or reclaiming it requires a separate operation, resulting in lower productivity and higher expense. 
     Efforts have been made in the past to manipulate the shape of the roll box for the purpose of accelerating the removal of fully ginned seed from the seed roll. An example is shown in U.S. Pat. Reg. No. 4,974,294 issued to Vandergriff entitled Cotton Gin Seed Vanes and Seed Roll Box, wherein a set of spaced-apart vanes are attached to an adjustable finger shaft thereby allowing for the increased width of the seed passage which aids in increasing the rate of discharge of ginned seeds. The vanes extend from the finger shaft mounted across the breast below the bottom edge of a flat or planar surface of the roll box. The vanes extend from the breast into the seed passage when the breast is closed for operation to prevent the seed roll from sagging too deeply into the seed passage and to purposefully slice into the seed roll with the intent of rupturing the lint-covered surface of the seed roll to more easily allow ginned seeds from the interior of the seed roll to escape. The vanes are spaced apart on the finger shaft to allow ginned seed to fall between them down through the seed passage. 
     A thorough description of a variety of commercially available gin saw stands and their operation is provided by Anthony and Mayfield (ed.), Cotton Ginner&#39;s Handbook, Agricultural Handbook No. 503, United States Department of Agriculture, Agricultural Research Service, Washington, D.C., 1994, the contents of which are incorporated in their entirety by reference herein. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a novel gin saw stand having a roll box, the shape of which may be adjusted during operation of the gin saw. Adjustment is possible through movement of one or more members making up one or more segments of the roll box surface. Specifically, the present invention provides a power operated roll box door that may be moved and stopped at any point between fully-opened and fully-closed positions. The roll box door may be adjusted manually or may be operatively connected to a powered means for movement. The present invention also proves a seed roll retaining member that many be adjusted during operation of the gin saw to re-shape the roll box. The seed roll retaining member may be adjusted manually or may be operatively connected to a powered means for movement. 
     The seed roll retaining member is further biased to extend to its fullest extent towards the cylindrical saw when the breast of the gin saw stand is opened to provide support for and substantially retain the seed roll in place above the saw. When closed, the seed roll retaining member is not extendable to the maximum extent, and is only capable of such extension when the breast is opened. 
     It is therefore an object of the present invention to provide an improved gin saw stand having a roll box with one or more surfaces that are adjustable to reconfigure the size of the roll box during ginning operations. 
     It is another object of the present invention to provide a gin saw stand having a powered roll box door positionable anywhere between its fully-opened and fully-closed positions. 
     A further object of the present invention is to provide a gin saw stand having a roll box retainer member which is adjustable during ginning operations to modify the shape of the roll box and which automatically extends even further into the seed discharge shaft to provide support for the seed roll when the breast is opened. 
     Another object of the present invention is to provide a gin saw stand having a cam shaft assembly allowing for fine adjustment of the seed roll retaining member to enhance the performance of the gin saw by adjusting the width of the seed discharge shaft. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The particular features and advantages of the invention as well as other objects will become apparent from the following description taken in connection with the accompanying drawings in which: 
         FIG. 1  is a side cross section view of a conventional gin saw stand of the prior art. 
         FIG. 2  is a side cross section view of the gin saw stand of the present invention. 
         FIG. 3  is a side cross section of a portion of the breast and saw of the present invention with the breast in the ginning or closed position illustrating the range of motion of the seed roll retaining member utilizing the cam and cam shaft mechanism. 
         FIG. 4  is a side cross section of a portion of the breast and saw of a less preferred embodiment of the present invention with the breast in the ginning or closed position illustrating the full range of motion of the seed roll retaining member utilizing the integral shaft of the seed roll retaining member. 
         FIG. 5  is a side cross section of a portion of the breast and saw of the present invention with the breast in the open position illustrating the range of motion of the seed roll retaining member utilizing the cam and cam shaft mechanism. 
         FIG. 6  is a side cross section of a portion of the breast and saw of the present invention with the breast in the open position illustrating the range of motion of the seed roll retaining member utilizing the integral shaft of the seed roll retaining member. 
         FIG. 7  is a partial right side front view of the breast of the present invention. 
         FIG. 8  is a right side view of the breast of the present invention. 
         FIG. 9  is a left side view of the breast of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As illustrated in  FIG. 2 , the gin saw stand of the present invention  50  comprises an inlet cotton chute  11  wherein the seed cotton is deposited leading to a picker roller  21  which assists in guiding the seed cotton against the periphery  15  of the circular blades  13  of cylindrical saw  12 . The inlet cotton chute  11  is defined within the breast  18  of the gin saw stand  50  by rear and front panels  56  and  57 , respectively, transversely spanning the breast  18  and first  54  and second breast side panels  55  (shown in  FIGS. 8 and 9 ) of the breast  18 . 
     The picker roller  21  throws the seed cotton in the inlet cotton chute  11  against the outer periphery  15  or teeth of the saw  12  which draws the locks of cotton upward through the seed discharge shaft  31  and into the lower portion of the roll box  25  positioned above the axis  14  of the saw  12  where the seeds with attached cotton accumulate into the seed roll. In the present invention, the seed discharge shaft  31  is defined by the space or shortest distance between the ginning ribs  26  and the curved bottom elbow  61  of the seed roll retaining member  60 . As illustrated in  FIG. 2 , when the breast  18  is in the closed position, as it is during ginning operations, the blades  13  of the saw  12  extend through the ginning ribs  26  and into the seed discharge shaft  31 . 
     As previously discussed, seed cotton remains circulating within the roll box  25  until the ginning action of the saw  12  and ginning ribs  26  remove substantially all of the cotton lint from the seeds. The lint is pulled from the seeds through the ginning ribs  26  where it is removed from the teeth of the saws by the doffing brush  27  and passes out of the gin stand  50  through the doffing outlet  29 . Contemporaneously, as the seeds in the seed roll become substantially free of lint, they are no longer held within the surface of the seed roll and may fall out of the bottom of the seed roll, passing gravitationally through the seed discharge shaft  31  and into a seed collection area  32  in the front lower portion of the gin saw stand  50 . 
     As in the prior art, the roll box cavity  25  of the present invention is of a somewhat distorted cylindrical configuration, however, unlike in prior art gin saw stands  10 , one or a plurality of the plurality of exposed, inwardly facing surfaces that shape the roll box cavity  25  are adapted to be moved to re-shape the roll box cavity  25 , and thus the seed roll formed within it, while the gin saw stand  50  is actively ginning the seed cotton of the seed roll. In a presently preferred embodiment, the roll box cavity  25  is defined by a plurality of exposed, inwardly facing (relative to the roll box) surfaces, namely, the upper portions  26   a  of the ginning ribs  26 , the inner surface member  68  of upper rib support  34 , the concavely curved inner surface  64  of roll box door member  63 , one or more upper breast sheet members  66  and the inner surface  59  of the proximal end  58  of the seed roll retaining member  60 . In the roll box  25  of the present invention  50 , a gap  35  exists between the outer end  71  of the door member  63  and the upper sheet member  66  of the breast  18 . 
     Door member  63  is hinged to the breast  18  at one or more pivot points, such as a transversely spanning shaft or axis  65 . Door member  63  rotates about the pivot point between a fully-closed position and a fully-opened position. Means for moving and holding the door member at any position between the fully-closed and fully-opened positions is provided, such as pneumatic door cylinder  72  attached to the shaft  65  on the outside  54  of breast  18 . Alternate means for moving the door, such as a hydraulic piston or powered gears or other conventional motors are within the contemplation of this invention. Preferably, the door member  63  is capable of movement through an arc of between about 40 to about 60 degrees between the fully-opened and fully-closed positions, though greater ranges of motion up to about 180 degrees are potentially possible. When in the fully-closed position as illustrated in  FIG. 2 , door member  63  rests against the upper end  86  of upper rib support  34  or the inner surface member  68  of rib support  34 . 
     The seed roll retaining member  60  transversely spans the breast  18  of the gin saw stand  50  substantially parallel to the axis  14  of the saw  12 . The seed roll retaining member  60  is a substantially continuous surface or sheet transversing the breast  18  without perforations, gaps or breaks, and is typically formed of sheet metal, though it may be formed of any suitable substantially rigid material. A first end of the proximal end  58  of the seed roll retaining member  60  is pivotably attached to the breast  18  at one or more pivot points such as transversely spanning seed roll retaining member axis  88  (also referred to herein as the integral shaft). The pivot point  88  is positioned immediately below the lower end  67  of breast sheet member  66  such that the inner surface  59  of the breast sheet member  66  and the inner surface of the proximal end  58  of the seed roll retaining member  60  form a relatively continuous surface of roll box  25 . 
     Seed roll retaining member  60  further comprises an elbow end  61 , preferably rounded, at the opposing second end of the proximal end  58  opposite the pivot point  88 , forming an angle between the proximal end  58  and the distal end  62 . The distal end  62  is angled relative to the proximal end  58  such that it remains in slidable contact with the lower end  52  of rear panel  57  of breast  18 , preferably the rear surface of the lower end  52  so that there is a relatively smooth transition between the lower end  52  and the distal end  62  of the seed roll retaining member  60 . Maintaining contact between the seed roll retaining member  60  and the lower end  52  of the rear panel  57  of the cotton inlet chute  11  at all times, regardless of whether the seed roll retaining member  60  is in the fully-extended or fully-retracted position or anywhere in between is important to present a continuous surface that blocks seed cotton from being thrown up behind the seed roll retaining member  60  when it is extended and thereby preventing the seed cotton from becoming trapped under the seed roll retaining member  60  and potentially clogging or inhibiting the free rotation of the seed roll retaining member  60  during operation of the gin. 
     In the preferred embodiment of the present invention  50 , the proximal end  58  and distal end  62  of the seed roll retaining member  60  are spaced-apart members rather than opposite sides of a solid member to reduce overall weight. One or more substantially triangular or pie-shaped supports  92  are spaced along the length of the seed roll retaining member  60  between the proximal end  58  and distal end  62  to maintain the shape of the seed roll retaining member  60  by keeping the proximal end  58  and distal end  62  separated. An opposing pair of outermost supports  92  are positioned flush with the ends of the seed roll retaining member  60  which are, in turn, substantially flush with the sides  54 ,  55  of the breast  18 . In a preferred embodiment, each support  92  has a chamfer  83  or blunted point proximate to where it fits into the elbow  61  to avoid the necessity of meeting fine tolerances when assembling the seed roll retaining member  60 . 
     In an alternate embodiment not shown in  FIG. 2 , the seed roll retaining member  60  could be formed as a solid piece with the outward surface  59  of proximal end  58  and distal end  62  being merely the different sides of a solid member. However, based on currently used materials, a solid seed roll retaining member  60  would be unnecessarily heavy and not practicable. Similarly, another alternative not illustrated is to form the seed roll retaining member  60  as a substantially triangular tube. 
     As illustrated in  FIG. 4 , the seed roll retaining member  60  is rotatably attached to the axis  88  so that it may rotate between a first, fully-retracted position (illustrated in solid lines) and a second, fully-extended position (illustrated in dashed lines) through an arc (α) of between about 20 degrees to about 40 degrees. 
     As illustrated in  FIG. 9 , means for moving and holding the seed roll retaining member  60  at any position between the fully-retracted and fully-extended positions is provided, such as retainer pneumatic cylinder  73  linked to the integral shaft  88 , such as by lever  85 . Retainer pneumatic cylinder  73  is preferably a fairly small bore cylinder and its normal state is retracted, thereby tending to keep the seed roll retaining member  60  in its fully-retracted position and its internal supports  92  engaged with the cams  91  of the cam shaft assembly  89 . 
     As shown in  FIG. 2 , the gin saw stand  50  further comprises a cam shaft assembly  89  for moving the seed roll retaining member  60 , particularly during ginning operations. The cam shaft assembly  89  comprises a cam shaft  90  transversing the breast  18  with an axis parallel to the integral shaft  88  of the seed roll retaining member  60 . One or more lobed or oblong cams  91  are carried upon the cam shaft  90  with each cam  91  normally in sliding contact with the seed roll retaining member  60 , preferably with an associated support  92  of the seed roll retaining member  60 . Turning the cam shaft  90  causes the lobe of the cam  91  to push upon the associated support  92  of the seed roll retaining member  60 , thereby moving the seed roll retaining member  60  between a normal fully-retracted position and a partially-extended position (illustrated in dashed lines in  FIG. 3 ). 
     As best illustrated in  FIGS. 7 and 8 , a means for moving the seed roll retaining member  60  via the cam shaft assembly  89  is provided, such as cam shaft lever  96  operatively attached to the cam shaft  90  and extending through a detented slot  97  in the front panel  56  of breast  18 . The means for moving the cam shaft assembly may be operated manually or by connection to some other power source such as a motor or pneumatic cylinder (not shown). In a preferred embodiment, lever  96  may be manually moved along the length of the slot  97  from a first end  98  to opposing second end  99  and stopped and held in each detention  95  of the slot  97 . When the lever  96  is positioned at one end  98  of the slot  97 , the seed roll retaining member  60  is positioned in the corresponding fully-retracted position, and when the cam shaft lever  96  is positioned at the other end  99 , the seed roll retaining member  60  is positioned in the corresponding partially-extended position. Catching the lever  96  in detensions  95  along the slot  97  positions the seed roll retaining member  60  at corresponding positions between the fully-retracted and the partially-extended positions. Preferably, the cam shaft lever  96  cannot be used to position the seed roll retaining member  60  in the fully-extended position, the limit of its extension by means of the lever  96  being the partially-extended position intermediate the fully-retracted position and fully extended position. 
     As illustrated in  FIG. 3 , the seed roll retaining member  60  may be moved via the cam shaft assembly through an arc Ω of between about 5 degrees to about 10 degrees. The magnitude of the adjustment may be changed by increasing or decreasing the size of the lobe of the supports  92  and by limiting or extending the range of motion of the cam shaft lever  96  within the slot  97  or a combination of both. Alternate means for moving the cam shaft assembly and thereby the seed roll retaining member  60 , such as a hydraulic piston or powered gears or other conventional motors are also within the contemplation of this invention. 
     In an alternative embodiment, the function served by cam shaft assembly could be accomplished by moving the seed roll retaining member  60  during ginning operations using pneumatic cylinder  73  attached to the integral shaft  88 . The cylinder  73  may be equipped with a linear positioning device providing exact piston location within the cylinder and a control panel on the gin  50  configured to provide an adjustment range similar to the range available using the manual lever  96 . Another potential method of moving the seed roll retaining member  60  during ginning operations would be the use of a ball screw actuator equipped with a rotary encoder. Other means common in the art are also within the contemplation of this invention, but are not as favored as the cam shaft assembly  89  due to increased costs. 
     In one preferred embodiment, the seed roll retaining member  60  is configured such that it can only be moved into the fully-extended position by the retainer pneumatic cylinder  73  but not cam shaft assembly. Allowing the positioning of the seed roll retaining member  60  into the fully-extended position using the manual lever  96  of the cam shaft assembly or other means may be potentially disadvantageous because, as shown in  FIG. 4 , with the breast  18  in the operative, ginning position, fully extending the seed roll retaining member  60  would substantially close off or restrict the unobstructed portion of the seed discharge shaft  31  not occupied by the blades  13  of the saw  12 , said open span being referred to herein as the open shaft span  93 . Substantially restricting or closing off the open shaft span  93  of the seed discharge shaft  31  also substantially closes off or restricts the path for new seed cotton as it is pulled upward by the periphery  15  of the saw  12  into the roll box  25 . If the width of the open shaft span  93  is too restricted or made too small, seed cotton in the gin  50  will tend to choke or clog up at that point, leading to extremely undesirable results and, potentially, failure of the gin  50 . Accordingly, the cam shaft assembly is preferably mechanically restricted by an appropriate physical limiting structure so that it cannot be used to move the seed roll retaining member to the fully-extended position when the breast  18  is closed, such as by limiting the size of the lobes of the cams  91  or restricting the movement of the cam shaft lever  96 . Similarly, the pneumatic cylinder  73  cannot be operated to fully extend the seed roll retaining member  60  when the breast  18  is closed. Only contemporaneously with or after the flow of seed cotton into the inlet cotton chute  11  has been cut off, which will result in substantially all of the seed cotton in the chute  11  being drawn up into the roll box  25  within a matter of a few seconds, may the breast  18  begin the process of being drawn away from the saw cylinder  12  by the pneumatic breast cylinder  47 . 
     As best shown in  FIG. 3 , the present invention  50 , the seed discharge shaft  31  is defined by the distance (y) between the ginning ribs  26  and the elbow  61  of the seed roll retaining member  60 , and the open shaft span  93  is defined by the distance (z) between the elbow  61  and the periphery  15  of the saw cylinder  12 . The ability to manipulate or vary the width of these distances, both when the breast  18  is opened and when it is closed, is an essential goal of the present invention because even relatively slight adjustments to these distances can generate tremendous performance enhancement in the operation of the gin  50  and substantially reduce the loss of unginned seed cotton when the breast  18  is opened. In particular, the ability to extend the seed roll retaining member  60  to within a few inches of the ginning ribs  26  when the breast  18  is open is a substantial improvement not accomplished in the prior art. 
     When the breast  18  is closed and the seed roll retaining member  60  is positioned in the fully-retracted position, the width (y) of the seed discharge shaft  31  is about 3.5 inches (about 8.9 cm) and the width (z) of the open shaft span  93  is about 1.5 inches (about 3.8 cm). When the breast  18  is closed, the distance (z) of primary importance is the open shaft span  93 , and the width (y) of the seed discharge shaft  31  is of only secondary importance because in different models of gin saw stands, the distance the saw blades  13  extend past the ginning ribs at this closest point my vary. Variations in the shape or contour of the ginning ribs  26  proximate to this point may also result in differences in the width (y) of the seed discharge shaft  31 , but the operational improvements result from the ability to vary the width (z) of the open shaft span  93 . 
     When the breast  18  is closed and the seed roll retaining member  60  is extended to the greatest extent possible by manual adjustment with the cam shaft lever  96  (i.e., an intermediate partially-extended position) as shown in  FIG. 3  in dashed lines, the width (z′) of the open shaft span  93  is about 15/16 inches (about 2.4 cm) and the width (y′) of the seed discharge shaft  31  is about 3 inches (about 7.6 cm). 
       FIG. 4  illustrates a non-preferred embodiment in which the seed roll retaining member  60  is configured to extend to its fully-extended position when the breast  18  is closed. In such a configuration, the width (z′) of the open shaft span  93  is about 3/16 inches (about 0.5 cm) and the width (y′) of the seed discharge shaft  31  is about 2 inches (about 5.1 cm). However, as previously discussed, reducing these widths to such an extent tends to result in clogs and blockage of the open shaft span  93  and seed discharge shaft  31 . Even in such a configuration, when the breast  18  is closed, meaning the blades  13  of saw  12  are extended to the fullest extent between the ginning ribs  26 , the proximal end  58  must not be of such a length that the elbow  61  would come into contact with the periphery  15  of the blades  13 . In other words, the elbow  61  can be configured to pass extremely closely over the surface of the saw  12 , but actual contact between the two should be physically impossible to avoid damage to the seed roll retaining member  60  and blades  13 . 
     Preferably, the means for moving the seed roll retaining member  60  via the integral shaft  88  is configured to preclude it from reaching the fully-extended position except when the breast  18  is opened, and then preferably only when the breast  18  is also opened to its fullest extent. In a preferred embodiment, the seed roll retaining member  60  is biased to automatically extend to the fully-extended position when the breast  18  is opened, thereby automatically shortening the distance between the ginning ribs  26  and elbow  61  (i.e., the seed discharge shaft  31 ) to the fullest extent possible, and thereby providing additional support for the seed roll along the proximal end  58  of the seed roll retaining member  60  and substantially reducing the likelihood that significant portions of the seed roll within the roll box  25  will break away and fall through the seed discharge shaft  31  and into the seed collection area  32 . 
     Biasing of the seed roll retaining member  60  to the fully-extended position when the breast  18  opens may be accomplished in many ways familiar in the art, such as simply programming pneumatic cylinder  73  to actuate in coordination with the actuation of the pneumatic cylinder  47  that moves the breast  18 . Other means for mechanically biasing the seed roll retaining member  60  are within the contemplation of this invention, such as connecting a lever on roll retainer member  60  to a mechanical linkage actuated by the motion of the breast  18  drawing away from the saw  12 . Alternately, and not by way of limitation, the retainer cylinder  73  may be linked or otherwise programmed to operate to extend the seed roll retaining member  60  to the fully-extended position only in tandem with the opening of the breast  18  by the breast cylinder  47 . 
     When the breast  18  is open as shown in  FIG. 5 , the width (y) of the seed discharge shaft  31  is the tolerance of primary importance because the periphery  15  of the saw cylinder  12  is substantially withdrawn from between the ginning ribs  26  thereby completely clearing or removing any impediments from the seed discharge shaft  31 . As a practical matter, it will be apparent that when the breast  18  is opened, the width (y) of the seed discharge shaft  31  and the width (z) of the open shaft span  93  are substantially identical. As stated above, the open shaft span  93  is defined as the portion of the seed discharge shaft  31  not occupied by the blades  13  of the saw  12 . When the breast  18  is open, no material portion of the seed discharge shaft  31  is occupied by the blades  13 . 
     As best illustrated in  FIG. 4 , when the breast  18  is in the fully-extended position, the internal supports  92  of the seed roll retaining member  60  are drawn away from contact with the associated cams  91 , even if the cam shaft  90  is turned so that the lobe of the cams  91  would otherwise be extending the seed roll retaining member  60  to an intermediate position (as shown in dashed lines in  FIG. 3 ). When the pneumatic cylinder  73  attempts to return the seed roll retaining member  60  to its normal fully-retracted state, as it is withdrawn, the supports  92  would come back into contact with the extended cams  91 , and thus the seed roll retaining member  60  would remain in the position to which the cam shaft assembly is set, rather than returning to the fully-retracted state. Thus, during operation, once a desirable setting of the width (y)of the seed discharge shaft  31  has been achieved using the cam shaft assembly  89  to move the seed roll retaining member  60 , the breast  18  can be opened, which results in the automatic movement of the seed roll retaining member  60  to its fully-extended position, then the breast  18  can be closed again and the seed roll retaining member  60  will assume the position last set by the cam shaft assembly  89  and does not require additional adjustment. 
     As shown in  FIG. 6 , when the breast  18  is opened and the seed roll retaining member  60  is in the fully-extended position (illustrated in dashed lines), the proximal end  58  has a length configured to result in a seed discharge shaft  31  having a width (y′) of about 2.0 inches (about 5.1 cm) or less and the distance (z′) between the elbow  61  and the periphery  15  of the saw  12  is about 2.5 inches (about 6.4 cm) or greater. Fully extending the seed roll retaining member  60  when the breast  18  is open serves the function of supporting the seed roll and preventing it, or portions thereof, from falling through the seed discharge shaft  31 . This supportive function is not materially served when the seed discharge shaft  31  is greater than about 4¾ inches (about 12 cm) in width (y′); no meaningful support is provided when the seed discharge shaft  31  is more than about 6 inches (about 15 cm) in width (y′), with the seed roll or substantial parts thereof being lost the majority of the time at this width. When the breast  18  is opened and the seed roll retaining member  60  is in the fully-retracted position (illustrated in solid lines in  FIG. 6 ), the width (y) of the seed discharge shaft  31  is about 3.5 inches (about 8.9 cm) and the distance (z) between the elbow  61  and the periphery  15  of the saw  12  is about 4.0 inches (about 10.2 cm) or greater. 
     As illustrated in  FIG. 5 , when the breast  18  is opened and the seed roll retaining member  60  is extended to the greatest extent possible by manual adjustment with the lever  96  (illustrated in dashed lines), i.e., the partially-extended position, the width (y′) of the seed discharge shaft  31  is about 3.0 inches (about 7.6 cm) and the distance (z′) between the elbow  61  and the periphery  15  of the saw  12  is about 3 7/16 inches (about 8.7 cm) or greater. 
     Although this invention has been disclosed and described in its preferred forms with a certain degree of particularity, it is understood that the present disclosure of the preferred forms is only by way of example and that numerous changes in the details of operation and in the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.