Patent Publication Number: US-11660633-B2

Title: Spreader for particulate material with improved spread control

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional application of U.S. patent application Ser. No. 16/770,140 filed Jun. 5, 2020, which is a national entry of International application PCT/CA2018/051562 filed Dec. 6, 2018, which claims the benefit of U.S. Provisional Patent Application Ser. No. 62/595,844 filed Dec. 7, 2017, the entire contents of all of which are herein incorporated by reference. 
    
    
     FIELD 
     This application relates to apparatuses for spreading particulate material. 
     BACKGROUND 
     Spinner spreaders are known in the art for broadcasting particulate material to a ground surface (e.g. an agricultural field, a road, and the like) for a variety of applications, for example, spreading fertilizer, fertilizer supplements, seed, sand, gravel, road salt, lime and the like. Spread pattern of the particulate material is dependent on spinner design, including size, placement and orientation of fins on a spinner disc, and on rotational speed of the disc. Distance to which particulate material is ejected may be controlled by the spinner design and the rotational speed of the disc, but uniformity of the spread pattern may be unduly affected when the disc speed is changed, especially when the rotational speed is reduced below a certain rate. However, for some applications, it is desirable to be able to reduce the disc speed while maintaining a uniform spread pattern. In other applications, it is desirable to be able to manipulate the spread pattern to provide a desired pattern. 
     Therefore, there remains a need in the art for a spinner spreader that provides greater control over spread pattern. 
     SUMMARY 
     There is provided an apparatus for spreading particulate material, the apparatus comprising: a bin for holding particulate material; a rotatable disc for broadcasting the particulate material to a ground surface; a conveyor for conveying the particulate material in a particulate material path from the hopper to the rotatable disc; and, a plurality of sluices situated in the particulate material path between the bin and the rotatable disc, each sluice receiving a portion of the particulate material and delivering the portion of particulate material to a radial and/or angular position on the rotatable disc, at least one of the sluices independently moveable to adjust the radial and/or angular position on the rotatable disc to which the portion of particulate material from the at least one independently moveable sluice is delivered, each sluice comprising substantially vertically oriented side walls, an open first end for receiving the particulate material from the conveyor, an inclined floor inclined downwardly from the first end to an open second end of the sluice so that the particulate material in the sluice flows freely out the open second end. 
     A method of controlling spread pattern of a particulate material broadcasted by a spinner spreader, the method comprising: permitting particulate material to flow through a plurality of sluices situated in a particulate material path between a bin and a rotatable disc of a spinner spreader, each sluice receiving a portion of the particulate material and delivering the portion of particulate material to a radial and/or angular position on the rotatable disc, each sluice comprising substantially vertically oriented side walls, an open first end for receiving the particulate material from the conveyor, an inclined floor inclined downwardly from the first end to an open second end of the sluice so that the particulate material in the sluice flows freely out the open second end; and, adjusting the radial and/or angular position on the rotatable disc to which the portion of particulate material from at least one of sluices is delivered by moving the at least one of the sluices relative to the rotating disc thereby changing the spread pattern of the particulate material broadcasted by the rotatable disc. 
     In an embodiment, each of the plurality of sluices is independently moveable to adjust the radial and/or angular positions on the rotatable disc to which the portions of particulate material from the independently moveable sluices are delivered. In an embodiment, the plurality of sluices comprises at least four sluices. Each of the sluices may be moveable longitudinally, transversely, vertically, rotationally or any combination thereof. Each sluice may be independently moveable in at least one of a longitudinal, transverse, vertical or rotational direction. Each sluice may be independently moveable in two, three or all four of the longitudinal, transverse, vertical and rotational directions. In some embodiments, the sluices may be collectively moveable in at least one of the longitudinal, transverse, vertical and rotational directions. The sluices may be collectively moveable in two, three or all four of the longitudinal, transverse, vertical and rotational directions. The ability to move the sluices in a number of different directions permits fine tuning of the spread pattern of the particulate material. 
     In an embodiment, each sluice comprises substantially vertically oriented side walls, an open top for receiving the particulate material from the conveyor, an inclined floor inclined downwardly from a first end to an open second end of the sluice so that the particulate material in the sluice flows freely out the open second end. In an embodiment, the sluices are disposed transversely to one another to form a series of parallel channels. In one embodiment, adjacent sluices of the series of parallel channels abut each other at the substantially vertically oriented side walls. In one embodiment, the sluices do not share common side walls. 
     The sluices are moveable using any suitable mechanism. For example, the sluices may be moveable manually, using one or more crank adjusters, using one or more linear actuators, using one or more hydraulic cylinders, using one or more pneumatic cylinders, or some combination thereof. Each sluice may be moveable by its own dedicated mechanism or mechanisms, or may be moveable by a mechanism or mechanisms common to more than one sluice. In an embodiment, the plurality of sluices comprises an elongated securing element that passes through aligned elongated slots in the side walls so that each of the sluices rests on the elongated securing element, each of the sluices independently translatable on the elongated securing element when not secured by the securing element and not translatable when secured by the securing element. In an embodiment, the elongated securing element comprises a threaded rod and one or more nuts, wherein tightening the one or more nuts on the rod immobilizes the sluices and loosening the one or more nuts on the rod permits the sluices to translate on the rod. 
     In an embodiment, the rotatable disc comprises first and second rotatable discs, and the plurality of sluices comprises first and second sets of sluices, the first set of sluices delivering the particulate material to the first rotatable disc and the second set of sluices delivering the particulate material to the second rotatable disc. 
     Deliberate control of the radial and/or angular position to which the particulate material is delivered to the rotatable disc and the speed at which the particulate material is delivered to the rotatable disc may be used to develop custom spread patterns for the particulate material. The rotational speed of the rotatable disc controls rotational positions at which the particulate material is broadcasted from the rotatable disc. The speed at which the particulate material is delivered to the rotatable disc controls the amount of particulate material delivered from the rotatable discs in a given time period. Manipulating these variables permits fine tuning the spread pattern of particulate material. Additionally, accuracy of the spread pattern may be further adjusted by altering the size and/or shape of the open rear ends of the sluices. For example, narrower sluices may reduce the likelihood of the particulate material shattering when delivered to the rotatable disc by localizing the particulate material more toward the center of the disc where rotational speed of the disc is lower. 
     Further features will be described or will become apparent in the course of the following detailed description. It should be understood that each feature described herein may be utilized in any combination with any one or more of the other described features, and that each feature does not necessarily rely on the presence of another feature except where evident to one of skill in the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For clearer understanding, preferred embodiments will now be described in detail by way of example, with reference to the accompanying drawings, in which: 
         FIG.  1    depicts a rear perspective view of one embodiment of a spinner spreader; 
         FIG.  2    depicts a side view of the spinner spreader of  FIG.  1   ; 
         FIG.  3    depicts a rear view of a spinner spreader of  FIG.  1   ; 
         FIG.  4    depicts a cross-sectional view through A-A in  FIG.  2   ; 
         FIG.  5    depicts a cross-sectional view through B-B in  FIG.  2   ; 
         FIG.  6    depicts a cross-sectional view through C-C in  FIG.  3   ; 
         FIG.  7    depicts the spinner spreader of  FIG.  1    including deflection plates over spinner discs; 
         FIG.  8    depicts a magnified side view of a rear end of the spinner spreader of  FIG.  7   ; 
         FIG.  9    depicts a division of particulate material spread pattern produced by the spinner spreader of  FIG.  7    with all sluices at the same longitudinal position; 
         FIG.  10 A ,  FIG.  10 B  and  FIG.  10 C  illustrate how particle spread pattern is affected by increasing ( FIG.  10 B ) and decreasing ( FIG.  10 C ) rotational speed of the spinner discs of the spinner spreader of  FIG.  7   ; 
         FIG.  11 A ,  FIG.  11 B  and  FIG.  11 C  illustrate how particle spread pattern is affected by forwardly ( FIG.  11 B ) and rearwardly ( FIG.  11 C ) moving a sluice of the spinner spreader of  FIG.  7   ; and, 
         FIG.  12    illustrates how moving sluices and adjusting rotational speed of spinner discs can be used to manipulate particle spread pattern to switch off one of eight broadcast sections of the spinner spreader of  FIG.  7   . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG.  1    to  FIG.  8   , one embodiment of a spinner spreader  1  comprises a hopper  5  mounted on a frame  10 , the frame  10  comprising a plurality of support rails  11  (only one labeled) for supporting the hopper  5  on the frame  10 . The frame  10  is mounted on a vehicle (not shown), for example a truck, a trailer and the like. The hopper  5  is designed to contain particulate material (e.g. fertilizer, fertilizer supplements, seed, sand, gravel, road salt, lime and the like) to be spread on a ground surface as the vehicle drives or is driven on or adjacent the ground surface. 
     The spinner spreader  1  further comprises a pair of adjacent conveyor belts  15  (only one labeled) situated at a bottom of the hopper  5  and oriented longitudinally with respect to direction of motion of the vehicle. The conveyor belts  15  transport the particulate material in the hopper  5  toward a rear of the hopper  5 , and therefore toward a rear of the spinner spreader  1 . The conveyor belts  15  comprise endless belts rotationally mounted on transversely oriented drive rollers  16  (only one labeled) located proximate the rear of the spinner spreader  1 , and on transversely oriented idler rollers  18  (only one labeled) located proximate a front of the spinner spreader  1 . The rollers  16 ,  18  are rotatably mounted on the frame  10 . There are separate drive and idler rollers  16 ,  18  for each conveyor belt  15  so that the conveyor belts may be driven independently, permitting driving the conveyor belts at different speeds, or even stopping one conveyor belt entirely, if desired. The two drive rollers  16  may be physically separated, or form a nested arrangement in which one of the drive rollers is hollow and a portion of the other of the drive rollers is mounted inside the hollow drive roller on bearings, permitting the two drive rollers to be operated independently. The same kind of nested arrangement may be utilized with the idler rollers  18 . The drive rollers  16  are driven by hydraulic motors  17  (only one labeled) mounted on the frame  10 . The conveyor belts  15  extend rearwardly pasta rear wall  7  of the hopper  5  transporting the particulate material out of the hopper  5  through a hopper outlet  8  into a transition box  12 . A flow divider  9  situated between the two conveyor belts  15  in the hopper  5  and the transition box  12  keeps the particulate material separated into two flow paths. 
     Two sets  20  (only one labeled) of individually translatable sluices  21  (only one in each set labeled) are disposed below rear ends  19  of the conveyor belts  15  to receive the particulate material flowing off the rear ends  19  of the conveyor belts  15 . One set  20  of sluices  21  is associated with one of the conveyor belts  15  and receives the particulate material from the one conveyor belt  15 . The other set of sluices receives the particulate material from the other conveyor belt, thereby keeping the flow paths of particulate material separate. Each of the sets  20  is shown with four individual sluices  21 , although the sets may comprise more or fewer sluices and/or each of the sets need not have the same number of sluices. In some embodiments, each set may have one, two, three, four, five, six or more sluices. 
     With specific reference to  FIG.  5    and  FIG.  8   , each of the sluices  21  comprise substantially vertically oriented side walls  22 . The sluices  21  have open tops, but are closed at a bottom and front thereof by an inclined floor  23 . The floor  23  is inclined downwardly from front to rear so that the particulate material may flow freely out of open rear ends of the sluices  21 . The open tops may comprise funnels  24  to guide particulate material from the conveyor belts  15  into the sluices  21  so that each sluice  21  receives a portion of the particulate material, each portion being substantially the same amount. The funnels atop the end sluices in each set of sluices may be flared outwardly from the sets of sluices to ensure that all of, or at least most of, the particulate material falling off the conveyor belts  15  enters the sluices  21 . 
     With specific reference to  FIG.  8   , the sluices  21  are disposed transversely to one another to form a series of parallel channels. Each of the side walls  22  of each of the sluices  21  comprise a longitudinally oriented elongated slot  25  situated in the side wall  22  below the floor  23 . All of the slots  25  in a given set of sluices are parallel to each other and transversely aligned so that a threaded rod  26  maybe inserted transversely through all of the slots  25  in the sluices of the given set thereby supporting all of the sluices in the given set on the rod  26 . Loosening one or more nuts, for example one or both of nuts  29  (see  FIG.  5   , only one labeled) on the threaded rod permits the sluices  21  to translate longitudinally forward and backward on the rod  26  by virtue of the elongated slot  25 . Once the sluices  21  have been moved to desired longitudinal positions, the nuts  29  may be tightened on the rod  26  to immobilize all of the sluices  21  in new longitudinal positions. Because each of the sluices  21  supported on the rod  26  are individual structures, the sluices  21  may be longitudinally positioned independently of each other. 
     The spinner spreader  1  further comprises deflection plates  30  (only one labeled) mounted on the frame  10  to a rear of the sets  20  of sluices  21 . The deflection plates  30  downwardly deflects the particulate material exiting from the open rear ends of the sluices  21 . 
     The spinner spreader  1  further comprises a pair of adjacent spinner assemblies  40  (only one labeled) mounted on the frame  10  at the rear of the spinner spreader  1  behind the hopper  5  and below the sluices  21 . If desired, the spinner assemblies may be mounted on a side of or in front of the hopper, with the sluices and conveyor belts positioned accordingly, but mounting the spinner assemblies behind the hopper is more typical in the art. Each spinner assembly  40  comprises a spinner disc  41  having a slightly concave upper surface that receives the particulate material from one set  20  of the sluices  21 . Each spinner assembly  40  comprises a substantially vertically oriented spinner drive shaft  42  attached to a center of the spinner disc  41  and to a spinner drive motor  43 . The spinner drive motor  43  is mounted on a spinner motor mount  45  mounted on the frame  10 . Operation of the spinner drive motor  43  causes the spinner disc  41  to rotate in a plane parallel to the ground surface. Particulate material from the sluices  21  landing on the spinner disc  41  is propelled horizontally off the spinner disc  41  under the influence of centripetal force to be broadcast outwardly from the spinner spreader  1 . The upper surface of the spinner disc  41  further comprises radially oriented fins  44 , which assist with propelling the particulate material off the disc  41 . The fins  44  may be designed to enhance throw distance and uniformity of spread pattern of the particulate material. While four fins  44  per spinner disc  41  are illustrated, each spinner disc  41  may comprise fewer or more fins, for example, each spinner disc  41  may comprise one, two, three, four, five, six or more fins. 
     The particulate material transported by one of the conveyor belts  15  through one set  20  of the sluices  21  is delivered to one of the spinner discs  41 , while the other spinner disc of the pair receives the particulate material transported by the other of the conveyor belts through the other set of sluices. Because the longitudinal position of the spinner discs  41  is fixed, longitudinal translation of an individual sluice  21  results in the portion of particulate material from the individual sluice  21  to fall on the corresponding spinner disc  41  at a different radial position on the disc  41 . Thus, swath control of the particulate material broadcast from each spinner disc  41  can be controlled independently for each disc  41  by independently controlling speed of the conveyor belts  15 , longitudinal position of each sluice  21  in each set  20  of sluices  21 , and rotational speed of each disc  41 . 
     While a pair of conveyor belts, two sets of sluices and a pair of spinner assemblies are illustrated in the embodiment shown in the Figures, it is understood that the spinner spreader may comprise one or more conveyor belt, one or more set of sluices and/or one or more spinner assembly, where one or more may be, for example, one, two, three, four or more. 
     Referring to  FIG.  9    to  FIG.  12   , the spinner spreader  1  provides improved control over spread pattern of the particulate material being broadcast by the spreader  1 . 
       FIG.  9    illustrates a division of particulate material spread pattern  50  (individually labeled as  50   a ,  50   b ,  50   c ,  50   d ,  50   e ,  50   f ,  50   g ,  50   h  for the particle spread pattern from each sluice) and particle trajectories  60  (individually labeled as  60   a ,  60   b ,  60   c ,  60   d ,  60   e ,  60   f ,  60   g ,  60   h  for the trajectory from each sluice) produced by the spinner spreader  1  when all of the sluices  21  (individually labeled as  21   a ,  21   b ,  21   c ,  21   d ,  21   e ,  21   f ,  21   g ,  21   h ) are at the same longitudinal position. The sluices  21  are in two sets  20  of sluices, the sets  20  individually labeled as left set  20   a  and right set  20   b . The sluices  21   a ,  21   b ,  21   c ,  21   d  are in the left set  20   a , while the sluices  21   d ,  21   e ,  21   f ,  21   g ,  21   h  are in the right set  20   b . The individual particle spread patterns  50   a ,  50   b ,  50   c ,  50   d ,  50   e ,  50   f ,  50   g ,  50   h  correspond to the individual trajectories  60   a ,  60   b ,  60   c ,  60   d ,  60   e ,  60   f ,  60   g ,  60   h , respectively, which correspond to the individual sluices  21   a ,  21   b ,  21   c ,  21   d ,  21   e ,  21   f ,  21   g ,  21   h , respectively. Particle flow paths from each sluice  21   a ,  21   b ,  21   c ,  21   d ,  21   e ,  21   f ,  21   g ,  21   h  are illustrated in dashed lines. 
     Still referring to  FIG.  9   , particulate material flowing out of the sluices  21  is delivered to the spinner discs  41  (individually labeled as left disc  41   a  and right disc  41   b ) to be broadcast to the ground following the illustrated trajectories  60 . The left disc  41   a  broadcasts particulate material delivered by the left set  20   a  of sluices and the right disc  41   b  broadcasts particulate material delivered by the right set  20   b  of sluices. The particulate material delivered from one of the sluices in one set of sluices is dropped on the associated spinner disc at a different radial distance from a center of the spinner disc than the particulate material delivered from the other of the sluices in that set. For example, the particulate material from the outermost sluice  21   a  in the left set  20   a  is dropped on the left disc  41   a  proximate a center  48   a  of the left disc  41   a . In comparison, the particulate material from the innermost sluice  21   d  in the left set  20   a  is dropped on the left disc  41   a  proximate a periphery  49   a  of the left disc  41   a . Consequently, the particulate material from the outermost sluice  21   a  spends more time on the left disc  41   a  and has a more rearward trajectory  60   a  compared to the particulate material from the innermost sluice  21   d  when the respective particulate materials are finally broadcast by the spinning left disc  41   a . The two middle sluices  21   b ,  21   c  deliver particulate material at different radial positions on the left disc  41   a , which are intermediate between the more central position of the particulate material from the outermost sluice  21   a  and the more peripheral position of the particulate material from the innermost sluice  21   d . An equivalent arrangement applies to the right disc  41   b  having a center  48   b  and a periphery  49   b , and servicing the right set  20   b.    
     As can be seen in  FIG.  9   , the arrangements of sluices  21  and spinner discs  41  described above can provide a uniform spread pattern  50  of particulate material through an angle of about 240° behind the spreader  1 . 
     The trajectory and spread pattern of particulate material delivered from an individual sluice is affected by the rotational speed of the spinner discs. Thus, the integrity of the spread pattern illustrated in  FIG.  9    would be disrupted if an operator wants to alter the rotational speed of one or more of the spinner discs. For example, with reference to  FIG.  10 A ,  FIG.  10 B  and  FIG.  10 C , increasing the rotational speed of the right disc  41   b  ( FIG.  10 B ) in comparison to a ‘normal’ rotational speed ( FIG.  10 A ) causes the particulate material delivered to the right disc  41   b  from the sluice  21   e  to be broadcast from the right disc  41   b  at a position transversely rightward from the position the particulate material is delivered at the ‘normal’ rotational speed of the right disc  41   b . Thus, the trajectory  60   e  and the spread pattern  50   e  of the particulate material delivered by the sluice  21   e  are skewed to the right when the rotational speed of the right disc  41   b  is increased (compare  FIG.  10 A  to  FIG.  10 B ). Conversely, decreasing the rotational speed of the right disc  41   b  ( FIG.  10 C ) in comparison to a ‘normal’ rotational speed ( FIG.  10 A ) causes the particulate material delivered to the right disc  41   b  from the sluice  21   e  to be broadcast from the right disc  41   b  at a position transversely leftward from the position the particulate material is delivered at the ‘normal’ rotational speed of the right disc  41   b . Thus, the trajectory  60   e  and the spread pattern  50   e  of the particulate material delivered by the sluice  21   e  are skewed to the left when the rotational speed of the right disc  41   b  is decreased (compare  FIG.  10 A  to  FIG.  10 C ). 
     The trajectory and spread pattern of particulate material delivered from an individual sluice may be altered by adjusting position of the individual sluice forward or rearward (i.e. longitudinally) with respect to the other sluices. Independent adjustment of the longitudinal position of an individual sluice adjusts the radial position at which the particulate material from the individual sluice is dropped on the spinner disc, because longitudinal position of the spinner disc remains fixed. The ability to independently adjust the longitudinal position of each sluice permits compensating for changes in the rotational speed of one or more of the spinner discs to maintain spread pattern integrity. For example, with reference to  FIG.  11 A ,  FIG.  11 B  and  FIG.  11 C , rearwardly translating the sluice  21   e  ( FIG.  11 B ) with respect to the other sluices causes the particulate material to drop on the right disc  41   b  radially closer to the center  48   b  than when the sluice  21   e  is in a ‘normal’ longitudinal position ( FIG.  11 A ). The particulate material therefore resides for a longer period of time on the spinning right disc  41   b  before being broadcast, resulting in the particulate material being broadcast in a particle trajectory  60   e  that is skewed to the right (compare  FIG.  11 A  to  FIG.  11 B ). As a result, the spread pattern  50   e  of the particulate material from the sluice  21   e  is also skewed to the right (compare  FIG.  11 A  to  FIG.  11 B ). Conversely, forwardly translating the sluice  21   e  ( FIG.  11 C ) with respect to the other sluices causes the particulate material to drop on the right disc  41   b  radially closer to the periphery  49   b  than when the sluice  21   e  is in a ‘normal’ longitudinal position ( FIG.  11 A ). The particulate material therefore resides for a shorter period of time on the spinning right disc  41   b  before being broadcast, resulting in the particulate material being broadcast in a particle trajectory  60   e  that is skewed to the left (compare  FIG.  11 A  to  FIG.  11 C ). As a result, the spread pattern  50   e  of the particulate material from the sluice  21   e  is also skewed to the left (compare  FIG.  10 A  to  FIG.  11 C ). Particle flow path from the sluice  21   e  is illustrated with a dashed line in  FIG.  11 A ,  FIG.  11 B  and  FIG.  11 C .  FIG.  11 A ,  FIG.  11 B  and  FIG.  11 C  illustrate that trajectory and spread pattern of the particulate material delivered from any particular sluice can be skewed left or right by altering the longitudinal position of the particular sluice. 
     Deliberate control of the longitudinal position of one or more of the sluices, the rotational speed of one or more of the spinner discs and the speed of one or more of the conveyor belts can be used to develop custom spread patterns for the particulate material. The rotational speed of the spinner discs controls rotational positions at which the particulate material is broadcasted from the spinner discs. The speed of the conveyor belts controls rates at which the particulate material is delivered to the spinner discs.  FIG.  12    illustrates one possibility in which particle spread pattern is manipulated to switch off one of eight broadcast sections while maintaining a uniform spread pattern in the other seven broadcast sections. With reference to  FIG.  12   , the left set  20   a  of sluices and the right set  20   b  of sluices receive particulate material from a left conveyor belt  15   a  and a right conveyor belt  15   b , respectively. The left set  20   a  of sluices and the right set  20   b  of sluices deliver the particulate material to the left disc  41   a  and the right disc  41   b , respectively. The particulate material is normally broadcast into broadcast sections. The broadcast sections comprise four left-side sections  70   a ,  70   b ,  70   c ,  70   d  on a left side of the spreader  1 , the four left-side sections  70   a ,  70   b ,  70   c ,  70   d  each correlating to the four sluices  21   a ,  21   b ,  21   c ,  21   d  (see  FIG.  9   ), respectively, of the left set  20   a  of sluices. Likewise, the broadcast sections comprise four right-side sections  70   e ,  70   f ,  70   g ,  70   h  on a right side of the spreader  1 , the four right-side sections  70   e ,  70   f ,  70   g ,  70   h  each correlating to the four sluices  21   e ,  21   f ,  21   g ,  21   h  (see  FIG.  9   ), respectively, of the right set  20   b  of sluices. However, it may be desirable in some applications to switch off broadcasting the particulate material to section  70   h  while maintaining a uniform spread pattern across the other seven sections  70   a ,  70   b ,  70   c ,  70   d ,  70   e ,  70   f ,  70   g . To accomplish such a custom spread pattern, the left conveyor belt  15   a  and the left disc  41   a  may be operated at normal speeds with the left set  20   a  of sluices in the normal longitudinal positions, thereby delivering 1 unit of particulate material to each of the four left-side sections  70   a ,  70   b ,  70   c ,  70   d . On the right side, the right conveyor belt  15   b  may be operated at three-quarters of the normal speed, the right disc  41   b  may be operated at lower rotational speed and the right set  20   b  of sluices may be translated rearwardly. The lower rotational speed of the right disc  41   b  and the rearward translation of the right set  20   b  of sluices are balanced so that section  70   h  receives no particulate material, and the other three right-side sections  70   e ,  70   f ,  70   g  each receive the same amount of particulate material as each of the left-side sections (i.e. 1 unit), but each of the three right-side sections  70   e ,  70   f ,  70   g  receive particulate from two of the sluices of the right set  20   b  of sluices. Particle flow paths from each sluice are illustrated in dashed lines. Thus, section  70   e  receives 0.75 unit of particulate material from the sluice  21   e  and 0.25 unit of particulate material from the sluice  21   f ; section  70   f  receives 0.5 unit of particulate material from the sluice  21   f  and 0.5 unit of particulate material from the sluice  21   g ; section  70   g  receives 0.25 unit of particulate material from the sluice  21   g  and 0.75 unit of particulate material from the sluice  21   h ; and, section  70   h  receives no particulate material. Each of the sluices  21   e ,  21   f ,  21   g ,  21   h  of the right set  20   b  of sluices delivers a total of 0.75 unit because the right conveyor belt  15   b  is operated at three-quarters of the normal speed. However, the particulate material delivered by each of the four sluices  21   e ,  21   f ,  21   g ,  21   h  is divided between the three right-side sections  70   e ,  70   f ,  70   g  as a result of balancing the lower rotational speed of the right disc  41   b  with the rearward longitudinal translation of the right set  20   b  of sluices. Because the longitudinal position of each sluice is independently adjustable, it is possible to create many different spread patterns for a variety of different applications and situations by balancing longitudinal sluice positions, rotational speeds of the spinner discs and operating speeds of the conveyor belts. 
     The novel features will become apparent to those of skill in the art upon examination of the description. It should be understood, however, that the scope of the claims should not be limited by the embodiments, but should be given the broadest interpretation consistent with the wording of the claims and the specification as a whole.