Abstract:
A bi-chromal ball production apparatus and method where the bi-chromal ball material is fed from opposite sides of the disk, reconfiguring the internal geometry of the apparatus, and precisely configuring the bi-chromal ball material feeding slit. The bi-chromal ball production apparatus has a disk that rotates, a first supply structure that supplies a first bi-chromal ball material to the disk from a first direction, a second supply structure tube that supplies a second bi-chromal ball material to the disk from a second direction and a motor that rotates the disk. The bi-chromal ball production apparatus includes a first reservoir and a first slit defined by the disk and a top body, a second reservoir and a second slit defined by the disk and a bottom body. An inner surface of each of the first and second reservoir is parabola shaped.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     This invention relates to producing bi-chromal balls for use in electric paper. 
     2. Description of Related Art 
     First and second color bi-chromal ball material with different electric and/or magnetic properties can be combined to form bi-chromal balls. FIG. 1 shows an exemplary bi-chromal ball  100  formed using a first color bi-chromal ball material  10  and a second color bi-chromal ball material  20 . The exemplary bi-chromal ball  100  has a magnetic or electric dipole oriented top to bottom. Thus, the bi-chromal ball  100  shown in FIG. 1 will rotate when subjected to various magnetic or electric fields. The bi-chromal ball  100  can be produced using various admixtures and materials as known in the art. 
     The bi-chromal ball  100  can be used in electric paper. In electric paper, many bi-chromal balls are placed next to each other in a matrix to form a sheet. The bi-chromal balls can be rotated to form letters and pictures by alternating the showing of either the first color or second color sides. 
     As shown in FIG. 2, the bi-chromal balls  100  are conventionally formed using a known spinner  1000 . The spinner  1000  has a bi-chromal ball material feeding portion  1220  and a spinning portion  1180 . The bi-chromal ball material is fed in through material supply tubes  1110  and  1140  to a pair of reservoir portions  1130  and  1170 . The bi-chromal balls  1190  are spun off of a disk  1200  of the spinning portion  1180 . The bi-chromal ball material feeding portion  1220  does not spin and includes the material supply tubes  1110  and  1140  and one or more O-rings  1210 . The O-rings  1210  are used to seal the ends of at least one of the material supply tubes  1110  and  1140 . 
     The spinning portion  1180  includes first and second bi-chromal ball material transport portions  1120  and  1150  and a pair of bi-chromal ball material reservoirs  1130  and  1170 . A first color bi-chromal ball material is fed through the material supply tube  1110 , into the second bi-chromal ball material transport portion  1150 , and flows through a third bi-chromal ball material transport portion  1160  into the bi-chromal ball material reservoir  1170 . A second color bi-chromal ball material is fed through the material supply tube  1140 , flows through the first bi-chromal ball material transport portion  1120  and into the bi-chromal ball material reservoir  1130 . The bi-chromal ball material is then forced outward from the bi-chromal ball material reservoirs  1130  and  1170  by the pressure in the material supply tubes  1110  and  1140  and by the centrifugal force of the spinning disk  1200  and flows along the surfaces of the disk  1200  until it forms the bi-chromal balls  1190 . The speed at which the bi-chromal ball material is fed to the disk  1200  to create the bi-chromal balls  1190  is controlled by the amount of pressure exerted on the bi-chromal ball material in the bi-chromal ball material supply tubes  1110  and  1140 . 
     Inside of the spinning portion  1180 , one color bi-chromal ball material is kept from the other color bi-chromal ball material in the bi-chromal ball material transport portions  1120  and  1150  by the one or more O-rings  1210 ,  1211 ,  1212  and  1213 . The one or more O-rings  1210  form a seal between the non-spinning bi-chromal ball material feed portion  1220  and the spinning portion  1180 , while the other O-rings are static and do not seal rotating parts. 
     U.S. Pat. Nos. 5,262,098 and 5,344,594, each incorporated herein by reference in its entirety, teach various methods for using liquids fed on opposite sides of a spinner to spread liquids. 
     SUMMARY OF THE INVENTION 
     This invention provides a bi-chromal ball production apparatus and method that is simpler to operate. 
     This invention separately provides a bi-chromal ball production apparatus and method that can operate at higher speeds. 
     This invention separately provides a bi-chromal ball production apparatus and method that has a greater control over the speed of the spinner. 
     This invention separately provides a bi-chromal ball production apparatus and method that has a higher yield of bi-chromal balls produced. 
     One or more of these various features and advantages of the invention are realized by feeding the bi-chromal ball material from opposite sides of the disk, reconfiguring the internal geometry of the apparatus and of controllably configuring the bi-chromal ball material feeding slit. 
     In various exemplary embodiments of the bi-chromal ball production apparatus according to this invention, the bi-chromal ball production apparatus has a disk that rotates, a first material supply tube that supplies a first bi-chromal ball material to a first side of the disk from a first direction, a second material supply tube that supplies a second bi-chromal ball material to a second side of the disk from a second direction, and a motor that rotates the disk. The bi-chromal ball production apparatus may include a first slit defined by the disk and a first housing and/or a second slit defined by the disk and a second housing. In various exemplary embodiments, the first and second slits each have a length of about 0.045 inches, a height of about 0.0025 inches and end at a distance of 0.775 inches from the center of rotation. 
     In various exemplary embodiments the apparatus may include a first reservoir portion defined by the disk, the first housing, the first slit and the first feed tube and a second reservoir portion defined by the disk, the second housing, the second slit and the second feed tube. In various exemplary embodiments, the disk may rotate at a speed of about 1800 revolutions per minute to about 5600 revolutions per minute. 
    
    
     These and other features and advantages of this invention are described in or are apparent from the following detailed description and drawings of the exemplary embodiments. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Various exemplary embodiments of the invention is described as referenced to the following figures, wherein like numerals identify like elements and wherein: 
     FIG. 1 illustrates a bi-chromal ball; 
     FIG. 2 is an exemplary cross-sectional view of a conventional spinner; 
     FIG. 3 is a cross-sectional view of a first exemplary embodiment of a bi-chromal ball production apparatus according to this invention; 
     FIG. 4 is a cross-sectional view of the bi-chromal ball production apparatus of FIG. 3 showing one exemplary embodiment of a bi-chromal ball material reservoir in greater detail; 
     FIG. 5 is a graph of the free surface position within the bi-chromal ball production apparatus according to this invention against revolutions per minute; 
     FIG. 6 is a cross-sectional view of a second exemplary embodiment of a bi-chromal ball production apparatus according to this invention; and 
     FIG. 7 is a top view of a portion of the bi-chromal ball producing apparatus of FIG.  6 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIG. 3 shows a first exemplary embodiment of a bi-chromal ball production apparatus  500  according to this invention. As shown in FIG. 3, the bi-chromal ball production apparatus  500  includes a spinner  570 , a rotor  580 , one or more bi-chromal material supply tubes  510  and  540 , one or more bi-chromal ball material transport portions  520  and  550 , one or more bi-chromal ball material reservoirs  530  and  560 , and one or more bi-chromal ball material slits  535  and  565 . 
     A first color bi-chromal ball material is fed through the first bi-chromal ball material supply tube  540  into a first bi-chromal ball material transport portion  520 , and then into a first bi-chromal ball material reservoir  560 . A second color bi-chromal ball material is fed through a second bi-chromal ball material supply tube  510  through a second bi-chromal ball material transport portion  580  and then into a second bi-chromal ball material reservoir  530 . The bi-chromal ball material in each of the first and second bi-chromal ball material reservoirs  530  and  560  is then fed through first and second bi-chromal ball material slits  535  and  565 , respectively, by centrifugal force along the spinner  570  and by the pressure in the supply tubes  510  and  540  to form the bi-chromal balls  590 . 
     Thus, in the first exemplary embodiment of the bi-chromal ball production apparatus  500  according to this invention shown in FIGS. 3 and 4, no part of the bi-chromal ball material transport portions  510  and  540  is formed as part of, or even comes into contact with, the rotating spinner  570 , eliminating the need to use the O-rings  1200  used in the conventional spinner  1000 . The O-rings  1200  are disadvantageous in the conventional spinner  1000 , since the O-rings  1200  introduce vibrations in the conventional spinner  1000  and thus limits its maximum rotating speed, and because the o-rings and the o-ring grooves are severely damaged by the abrasive nature of the pigmented bi-chromal ball material. 
     In addition, in various exemplary embodiments, the lack of contact between bi-chromal ball material transport portions  510  and  540  and the spinner  570  allows for centrifugal force to be the determining factor in the rate that bi-chromal ball material is supplied to the bi-chromal ball material slits  535  and  565 . As explained below, the bi-chromal ball material slits  535  and  565  can restrict the flow of the bi-chromal ball material out of the bi-chromal ball material reservoirs  530  and  560 , thus, depending on the rotational velocity of the spinner  570  and thus the resulting centrifugal force on the bi-chromal ball material in the bi-chromal ball material reservoirs  530  and  560 , as well as the flow rate of bi-chromal ball material through the bi-chromal ball material transport portions  520  and  550  into the bi-chromal ball material reservoirs  530  and  560 , the amount of bi-chromal ball material on the bi-chromal ball material reservoirs  530  and  560  remains within predetermined limits. Further, as explained below, the bi-chromal ball material reservoirs  530  and  560  can be used to smooth out irregularities in the flow of bi-chromal ball material through the bi-chromal ball material transport portions  520  and  550  and into the bi-chromal ball material reservoirs  530  and  560 . 
     In various exemplary embodiments, the bi-chromal ball material transport portions  520  and  550  are designed to operate over a selected flow rate range. While operating within this flow rate range, a stable amount of bi-chromal ball material flows through bi-chromal ball transport portions  520  and  550  and into the bi-chromal ball material reservoirs  530  and  560 . The bi-chromal ball transport portions  520  and  550  are thus able to deliver the bi-chromal ball material to the spinner  570  without needing to contact the spinner  570  or otherwise have any portion of either of the bi-chromal ball material transport portions  520  and  550  on any rotating element of the bi-chromal ball material production apparatus  500 . 
     FIG. 4 is cross-sectional view showing one exemplary embodiment of a reservoir portion  600  of the first exemplary embodiment of a bi-chromal ball production apparatus  500  shown in FIG. 3 in greater detail. The reservoir portion  600  of the bi-chromal ball production apparatus  500  includes a bi-chromal ball material transport portion  610 , a bi-chromal ball material reservoir  620 , a slit  630  formed on the side of a portion  670  of the spinner  570 , and a portion  690  of a housing used to form the bi-chromal ball material reservoir  620  and the bi-chromal ball material slit  630 . 
     As the bi-chromal ball material is fed down the bi-chromal ball material transport portion  610  at the selected flow rate, the bi-chromal ball material will gather in the bi-chromal ball material reservoir  620 . The centrifugal pressure that is built up in the bi-chromal ball material in the bi-chromal ball material reservoir  620  by the rotational velocity of the spinner  570  forces the bi-chromal ball material out of the bi-chromal ball material reservoir  620 , through the slit  630  and along the portion  670  of the spinner  570 . As outlined above, for any given dimensions for the bi-chromal ball material slit  630 , the rotational speed of the portion  670  of the of the spinner  570  controls the rate at which the bi-chromal ball material flows out of the bi-chromal ball material reservoir  620 , and thus the size, quality and the quantity of the bi-chromal balls  590  produced by the bi-chromal ball material product apparatus  500 . 
     The bi-chromal ball material slit  630  is subjected to atmospheric pressure on both the upstream (i.e., towards the bi-chromal ball material transport portion  610 ) side and the downstream (i.e., toward the edge of the spinner  570 ) side of the bi-chromal ball material slit  630 . Therefore, in the bi-chromal ball production apparatus  500 , the bi-chromal ball material is only subjected to centrifugal pressure generated by the rotational velocity of the spinner  570 . Once the bi-chromal ball material in the bi-chromal ball material reservoir is in contact with the surface of the portion  670  of the spinner  570 , the bi-chromal ball material is accelerated radially out of the bi-chromal ball material reservoir  620  towards the bi-chromal ball material slit  630 . 
     Due to the high flow restriction generated by the bi-chromal ball material slit  620 , where the flow resistance created by the bi-chromal ball material slit  630  is a function of the slit length and the gap slit, the bi-chromal ball material starts to build up in the bi-chromal ball material reservoir  620 , creating a constantly-moving free surface position  680 , until equilibrium is met between the pressure drop across the bi-chromal ball material slit  630  due to the flow resistance and the increasing pressure due to centrifugal force applied on the bi-chromal ball material due to increasing amounts of the bi-chromal ball material, in the bi-chromal ball material reservoir  620 . Once equilibrium is achieved, the bi-chromal ball material will flow out of the bi-chromal ball material reservoir  620  through the bi-chromal ball material slit  630  at a constant flow rate equal to the amount of bi-chromal ball material being delivered, i.e., the selected input flow rate of the bi-chromal ball material from the bi-chromal material transport portion  610  to the bi-chromal ball material reservoir  620 . 
     This remains the case as long as the incoming flow rate is within the selected flow rate range. The bi-chromal ball material free surface  680  is constantly moving inside the bi-chromal ball material reservoir  620 , along the radial direction, in order to achieve equilibrium between the bi-chromal ball material flowing out of the bi-chromal ball material reservoir  620  through the bi-chromal ball material slit  630  and the bi-chromal ball material entering the bi-chromal ball material reservoir  620  from the bi-chromal ball material transport portion  610 . In other words, a change to either the rotational velocity of the spinner  570  and/or flow rate of the incoming bi-chromal ball material from the bi-chromal ball material transport portion  610  will upset the system equilibrium, making the bi-chromal ball material free surface  680  move until a new equilibrium is met. 
     Outside of the normal range of operation, two failure modes could occur. First, if there is too much bi-chromal ball material being fed to the bi-chromal ball material reservoir  620  from the bi-chromal ball material transport portion  610 , and the system cannot find a new free surface position  680 , the bi-chromal ball material can over-fill the bi-chromal ball material reservoir  620 . As a result, a choked condition would occur. 
     The other possible failure mode occurs when the bi-chromal ball material transport portion  610  fails to supply enough bi-chromal ball material to the bi-chromal ball material reservoir  620 . This starves the bi-chromal ball production apparatus  600  such that the bi-chromal ball material reservoir  620  empties. In this condition, the free surface  680  inside the bi-chromal ball material reservoir  620  is never achieved. As a result, the bi-chromal ball material is not distributed evenly onto the surface of the spinner  670  through the bi-chromal ball material slit  630 , leading to poorly formed bi-chromal balls  590 . 
     In summary, the slit length and height gap of the bi-chromal ball material slit  630  formed between the housing  690  of the bi-chromal ball production apparatus  600  and the spinner  670  is a design parameter which can be specifically designed for a desired operating range. The flow resistance at the bi-chromal ball material slit thus creates in various exemplary embodiments, a reservoir effect. 
     As shown in FIG. 4, in various exemplary embodiments, the housing  690  has a curved in surface that forms one surface of the bi-chromal ball material reservoir  620 . As a result, once in the bi-chromal ball material reservoir  620  of the bi-chromal ball material apparatus  500 , the bi-chromal ball material may flow through the bi-chromal ball material reservoir  620  using a curved interior geometry. The interior geometry of the bi-chromal ball material reservoir  620  can be adjusted and/or selected or designed to achieve a desired flow rate of the bi-chromal ball material out of the bi-chromal ball material reservoir  620  and through the bi-chromal ball material slit  630 . In various exemplary embodiments, the curved interior geometry of the bi-chromal ball material reservoir  620  is parabolic. When used, the parabolic liquid flow path provides two advantages. First, the parabolic liquid flow path tends to accelerate the bi-chromal ball material out of the bi-chromal ball material reservoir  620  towards the bi-chromal ball material slit  630 . Second, the parabolic liquid flow path tends to eliminate the sharp corners against which bi-chromal ball material could build up to clog the bi-chromal ball material reservoir  620 . 
     In various exemplary embodiments according to this invention, the curved bi-chromal ball material flow path of the bi-chromal ball production apparatus  500  is straight-forward compared to the more complex flow paths used in the conventional spinner  1000 . In these exemplary embodiments, the curved flow path reduces the opportunity for the bi-chromal ball material to become clogged in any of the bi-chromal ball material transport portion or reservoir  610  or  620  or the bi-chromal ball material slit  630 , such as around the bend in the bi-chromal ball material transport portion  1210  that is present in the conventional spinner  1000 . 
     The bi-chromal ball reservoir  620  is, in various exemplary embodiments, parabola shaped. A parabola shape has been found to improve feeding the bi-chromal ball material from the bi-chromal ball material reservoir  620  to the spinner  570 . However, other shapes for the inner surface of the housing  690 , such as surfaces with angles and/or with more or less curvature, are also possible without departing from the spirit or scope of the invention. 
     In one exemplary embodiment, a slit length of 0.045 inches, a slit gap of 0.0025 inches and a distance from the center of rotation to the circumferential end of the bi-chromal ball material slit  630  of 0.775 inches produces the plot of the free surface position  680  against the rotational speed of the spinner  670  shown in FIG.  5 . 
     Thus, FIG. 5 shows a graph  800  of the free surface position  680  from the center axis versus the rotational velocity, in revolutions per minute, for the exemplary embodiment of the portion  600  of the bi-chromal ball production apparatus  500  shown in FIG.  4 . For a flow rate of 0.75 cc/second of the bi-chromal ball material through the bi-chromal ball material transport portion  610  into the bi-chromal ball material reservoir  620 , the free surface  680  in this exemplary bi-chromal ball production apparatus is described by the curve  810 . As shown in FIG. 5, when the rotational velocity is varied between around 2000 rpm and around 6700 rpm, the free surface  680  remains radially inside of the axial end of the bi-chromal ball material reservoir  620 , which is indicated by the line  830 , such that the bi-chromal ball material reservoir  620  does not become over filled and thus does not overflow. Similarly, the free surface  680  also remains radially outside of the circumferential end of the bi-chromal ball material reservoir  620 , indicated by the line  820  such that the bi-chromal ball material reservoir does not empty. Thus, when the rotational velocity of the spinner  620  is varied between around 2000 rpm to around 6700 rpm, the bi-chromal ball material will flow to the edge of the spinner  570  at a flow rate, in volume per radians, determined primarily, if not solely, by the rotational velocity of the spinner  570 . 
     Other free surface position curves are possible, depending on the speed of the spinner  570 , the flow rate of bi-chromal ball material into the bi-chromal ball material reservoir  620  and the size of the bi-chromal ball material slit  630 . In various exemplary embodiments, any or all of these parameters can be varied without departing form the spirit and scope of the invention. 
     Thus, in various exemplary embodiments of the bi-chromal ball production apparatus according to this invention, the bi-chromal ball material flow rate to the surfaces of the spinner  570  is driven primarily by centrifugal pressure. By driving the bi-chromal ball material flow rate by centrifugal pressure, the bi-chromal ball material supply portions, such as the bi-chromal ball material transport portions  510  and  540 , of the bi-chromal ball material production apparatus  500  can be isolated from the spinning portions of the bi-chromal ball material production apparatus  500 , such as the bi-chromal ball material transport portions  510  and  540 . This tends to eliminate the need for any physical contact between the bi-chromal ball material supply portions of the bi-chromal ball material production apparatus  500  and the spinning portions of the bi-chromal ball material production apparatus. 
     In contrast, in the conventional pressurized feeding system shown in FIGS. 1 and 2, that bi-chromal ball producing apparatus  1000  will not work without physical contact between these portions. Also, the internal geometry of the bi-chromal ball production apparatus according to this invention is robust enough to allow for minor variations in rotational velocity without adversely affecting the performance of the bi-chromal ball production apparatus  500 . In other words, bi-chromal ball material reservoir  520 ,  550  and/or  620  continuously self-adjust the volume of the bi-chromal ball material so that small variations in the rotational velocity of the spinner  570  do not adversely affect the flow rate of the bi-chromal ball material to the spinner  570 . Also, if the volume of the bi-chromal ball material reservoir  520 ,  550  and/or  620  is large enough, any variations in the flow rate due to inconsistencies in the amount of bi-chromal ball material supplied by the bi-chromal ball material transport portion  510 ,  540  and/or  610  will be averaged over time, reducing the magnitude of the flow rate variations, i.e., smoothing out those variations that pass to the spinner  570 . 
     FIG. 6 shows a second exemplary embodiment of a bi-chromal ball production apparatus  700  according to this invention. The bi-chromal ball production apparatus  700  includes a bi-chromal ball material supply portion  710 , a number of bi-chromal material reservoirs  720  and  740 , a number of bi-chromal ball material slits  730  and  750 , a first housing  760  a second housing  780  and a screw  790 . The slit  730  is defined by the spinner  770  and a first outer housing  768  of the first housing  760 . Likewise, the slit  750  is defined by the spinner  770  and a second outer housing  788  of the second housing  780 . The bi-chromal material reservoir  720  is formed by an inner housing  762  and the outer housing  768  of the first housing  760  and the spinner  770 . Likewise, the bi-chromal material reservoir  740  is formed by an inner housing  782  and the outer housing  788  of the second housing  780  and the spinner  770 . Each of the outer housings  768  and  788  have threads  764  and  784 , respectively, that mesh with threads  764  and  784  formed on the inner housings  762  and  782 , respectively. 
     As shown in FIG. 7, the inner housings  762  and  782  are supported by webs or columns  766  and  786  distributed around the circumference of the circular inner housings  762  and  782 . The screw  790  passes through the inner housing  762 , a pair of the columns  766  and  786 , the spinner  770  and into the inner housing  782 . 
     The slit  730  can be adjusted by turning the outer housing  768  relative to the upper housing  762 . Likewise, the slit  750  can be adjusted by turning the outer housing  788  relative to the inner housing  782 . 
     As noted above, the free surface position of the bi-chromal ball material inside the bi-chromal material reservoirs  720  and  740  is controlled by the flow resistance provided by the bi-chromal ball material slits  730  and  750 , respectively, and varies with the fluid properties of the bi-chromal ball material, the rotational velocity of the disc  770  and the amount of bi-chromal ball material being fed through the bi-chrome ball material supply portions  710  and  715 . Therefore, any change in the material properties or rotational velocity might cause a failure mode within the bi-chromal ball producing apparatus  500  or  700  according to this invention. However, in this second exemplary embodiment of the bi-chromal ball material production apparatus  700 , the bi-chromal ball material slit  730  can be adjusted by rotating the outer housing  768  relative to the inner housing  762  to move the outer housing  768  up or down to increase or decease the vertical size of the bi-chromal ball material slit  730  of the bi-chromal ball material production apparatus  700 . 
     This can be done independently of any adjustments to the bi-chromal ball material slit  750 . The bi-chromal ball material slit is itself adjusted by rotating the outer housing  788  relative to the inner housing  782  such that outer housing  788  moves up or down to make the vertical size of the bi-chromal ball material slit  750  larger or smaller. Thus, in the second exemplary embodiment of the bi-chromal ball material production apparatus  700  shown in FIGS. 6 and 7, the bi-chromal ball material slits  730  and  750  can be adjusted independently of each other, allowing for bi-chromal ball materials with different viscosities and reducing the likelihood that the bi-chromal ball material reservoirs  720  and/or  740  overflow or become clogged by undispensed bi-chromal ball material or large fibers within the bi-chromal ball material. 
     The second exemplary embodiment of the bi-chromal ball material production apparatus shown in FIGS. 6 and 7 can use the same type of thread system used in micrometers for the threads formed in the inner and outer housings  762 ,  768 ,  782  and  788 . The second exemplary embodiment of the bi-chromal ball material production apparatus can use a two-piece structure for each of the top and the bottom housings  760  and  780 . One part forms the majority of the internal geometry of the inner housings  762  and  782 . In this case, the inner housings  762  or  782  would be permanently mounted to the spinner  770  with the series of mounts  766 ,  786  and bolts  790 . The outer housings  768  and  788  can be attached to the inner housing  762  and  782  by the threads  764  or  786  on each housing  762 ,  768 ,  782  and  788 . By rotating the outer housing  768  or  788  relative to the inner housings  762  or  782 , the bi-chromal ball material slit  730  or  750 , respectfully, is opened or closed, depending on which direction the outer housing  768  or  788  was rotated relative to the inner housing  762  or  782 . In the second exemplary embodiment of the bi-chromal ball material production apparatus, calibration marks could be used on the inner housings  762  and  782  and a reference point on the outer housings  768  and  788  to indicate the slit size of the bi-chromal ball material slits  730  and  750 . 
     In various exemplary embodiments, the inner housings  762  and  782  and the outer housings  768  and  788  are machined out of heat-stable material because of the high temperatures encountered in operations. However, other materials may be used. 
     This second exemplary embodiment of the bi-chromal ball material production apparatus has been shown with the threads  764  and  784  formed on the interface between the inner housings  762  and  782  and the outer housings  768  and  788 . However, it should be appreciated that the adjustment threads can be placed in other areas in other exemplary embodiments. 
     While the adjustment mechanism in the second exemplary embodiment of the bi-chromal ball material production apparatus shown in FIGS. 6 and 7 uses threads  764  and  784  formed on the inner and outer housings  762  and  768 , and  782  and  788 , respectively, any other known or later developed devices, structures or apparatus usable to adjust the size of the bi-chromal ball material slits  730  and  750  can be used. 
     While this invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. For example, the bi-chromal ball material has been described as bi-chromal ball material of two different colors, and bi-chromal ball material of similar color but different properties may be substituted. Accordingly, preferred embodiments of the invention as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention.