Abstract:
A material spreader includes a belt/chain assembly. The belt is mounted within the chamber of the material spreader and the chain remains out of contact with the material during the operation of the device. A sliding barrier is mounted at the rear of the belt, and moves from a forward position adjacent the front of the spreader to a rear position adjacent the rear of the spreader. One form of the hydraulic system utilizes a sensor for built up pressure within independently driven augers. In response to this pressure build up the sliding barrier speed is reduced.

Description:
CROSS REFERENCE TO EARLIER APPLICATIONS 
   This is a continuation-in-part of pending application Ser. No. 10/673,625, filed Sep. 29, 2003, herein incorporated by reference. 

   BACKGROUND OF THE INVENTION 
   This invention relates to a material spreader and method for using same. It may be used for spreading manure, compost, sludge, paunch or other materials. Conventional material spreaders utilize a series of horizontal bars extending laterally across the floor of the spreader box. These bars move by chains in a rearward direction so as to carry the material rearwardly where it is spread by various types of rotating members. 
   One disadvantage of the present method for conveying the material to the rear of the spreader is that if a chain breaks or is damaged in any way, the entire contents must be removed from the wagon in order to make any repair. 
   Another disadvantage of prior methods relates to the feed mechanism for feeding the material to upstanding augers which spread the material to the rear of the spreader. If the feed mechanism moves too fast it can overload the spread augers and damage them. 
   Another disadvantage of prior methods of operating the upstanding spreading augers is that the two augers are driven by a single power source, whether that single power source be mechanical, electrical, hydraulic or pneumatic. This single source is used in order to coordinate the two augers. Without this coordination there is often high vibration resulting from rotation of the two augers. 
   Therefore, a primary object of the present invention is the provision of an improved material spreader and method for using same. 
   A further object of the present invention is the provision of an improved material spreader which utilizes a belt that spans the width of the material spreader box. 
   A further object of the present invention is the provision of a material spreader and method for using same which maintains a chain drive for moving a belt, wherein the chain drive is never exposed to the material carried by the belt. 
   A further object of the present invention is the provision of an improved material spreader and method for using same which utilizes a sliding barrier at the rear of the belt for moving the material in a rearward direction for discharge from the material spreader. 
   A further object of the present invention is to provide a sensor for sensing overload of the spreading augers and reduction of the feeding mechanism in response thereto. 
   A further object of the present invention is to provide separate and independent drive systems for each of the spreading augers. 
   A further object of the present invention is to reduce the vibration which normally results from rotation of the two spreading augers at the same time by driving the two augers independently of one another. 
   A further object of the present invention is the provision of a material spreader and method for using same which is economical to manufacture, durable in use, and efficient in operation. 
   BRIEF SUMMARY OF THE INVENTION 
   The foregoing objects may be achieved by a material spreader comprising a material spreader box having a bottom wall, opposite sidewalls, a front wall, and a rear wall forming a material storage chamber for storing a quantity of material. The bottom wall includes opposite side edges from which the opposite sidewalls extend upwardly. The bottom wall also includes a front end from which the front wall extends upwardly. A discharge opening is adjacent the rear end of the bottom wall. A conveyor belt is superimposed over the bottom wall and is positioned for supporting a quantity of material contained within the material storage chamber. The conveyor belt has a width that causes the conveyor belt to substantially completely cover the width of the bottom wall. A drive mechanism is connected to the conveyor belt for moving the conveyor belt relative to the bottom wall in a rearward direction toward the rear wall of the material spreader box whereby the conveyor belt will carry the quantity of material within the material storage chamber in a rearward direction and will discharge the material through the discharge opening at the rear end of the bottom wall. A beater assembly is mounted to the rear of the box for engaging and spreading the material exiting from the discharge opening. 
   According to another feature of the invention the drive mechanism comprises a chain and sprocket assembly connected to the conveyor belt. 
   According to another feature of the invention the chain and sprocket assembly is located outside the material storage chamber and is free from contact with the quantity of material stored within the material storage chamber. 
   According to another feature of the present invention the beater assembly comprises a plurality of beater bars mounted to the material spreader box for rotation about a plurality of upstanding axes. 
   According to another feature of the present invention the beater bars rotate about a plurality of horizontal axes. 
   According to another feature of the present invention a first roller and a second roller are spaced apart from one another and are mounted for rotation about first and second roller axes respectively. The conveyor belt is trained around at least one of the first and second rollers. 
   According to another feature of the present invention the chain and sprocket assembly comprises a sprocket on at least one of the first and second rollers and a chain engaging the sprocket for causing rotation of one of the first and second rollers. 
   The method of the present invention involves mounting a conveyor belt within the material chamber in close covering relation over the bottom wall and substantially covering the width of the bottom wall. A quantity of material is inserted within the material chamber so that the quantity of material rests upon the conveyor belt. The conveyor belt is moved towards the discharge opening in the rear wall whereby the quantity of material will be moved toward and discharged from the material chamber through the discharge opening. The material being discharged from the discharge opening is engaged and spread with rotating beater bars mounted to the rear of the rear wall of the material spreader box. 
   According to another feature of the present invention a method for spreading a quantity of material comprises rotating a first auger with a first auger drive and simultaneously rotating a second auger with the second drive independently of the first auger drive. 
   According to another feature of the present invention the first and second auger drives are hydraulic motors and the method comprises sensing the hydraulic pressure within the first and second hydraulic motors. Then the method comprises slowing the rate of the feed mechanism between the first and second positions in response to sensing an increase in the hydraulic pressure from the normal hydraulic pressure sensed in either the first and second hydraulic motors. 
   According to another feature of the present invention the material spreader includes a material spreader box having a bottom wall and opposite side walls forming a storage chamber for storing the quantity of material. At least a first upstanding auger and second upstanding auger are mounted to the spreader box for rotation of about first and second upstanding axis respectively. A first auger drive is provided for causing the first upstanding auger to rotate, and a second auger drive is used for causing the second upstanding auger to rotate. The first and second auger drives are independent from one another. A feed mechanism within the spreader box is movable between first and second positions to cause the quantity of material within the chamber to be fed to the first and second upstanding augers for spreading the material on the ground during the rotation of the first and second augers. 
   According to another feature of the present invention the sensor is responsive to pressure build up in either of the first and second hydraulic motors to cause the feed mechanism to slow down its movement between the first and second positions. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of the material spreader of the present invention. 
       FIG. 2  is a longitudinal sectional view of the material spreader shown in  FIG. 1 . 
       FIG. 3  is a longitudinal sectional view similar to  FIG. 2 , but showing the belt moved in a rearward direction from the position shown in  FIG. 2 . 
       FIG. 4  is a sectional view taken along line  4 — 4  of  FIG. 2 . 
       FIG. 5  is a perspective view of the vertically oriented beater bar assembly. 
       FIG. 6  is a pictorial view of an alternative form of beater bar assembly utilizing horizontally rotatable beater bars. 
       FIG. 7  is a rear elevational view of an alternative form of beater bar assembly utilizing lightings that extend along substantially the entire length of the shafts. 
       FIG. 8  is a schematic view of the hydraulics of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to the drawings, the numeral  10  generally designates a material spreader made according to the present invention. Material spreader  10  includes a spreader box  12  comprising opposite sidewalls  14 , an open front  16 , and an open rear end  18  ( FIG. 2 ). Bottom wall  20  provides a floor for the spreader box  12 . 
   A moveable gate  24  is mounted over the open rear end  18  and is capable of vertical pivoting movement from the position shown in  FIG. 1  to the position shown in  FIG. 2 . A belt/chain assembly  28  comprises a belt  30  and a chain  32 . Belt  30  is connected to the chain at its forward end by means of a connecting bar  34 . Connecting bar  34  includes a chain loop  36  which receives one end of the chain  32 . The rear end of the chain  32  is connected to a sliding barrier  38  having a flat rear face  40  and having a double concave front face  42  with a ridge  44  there between. The double concave front face  42  of the sliding barrier  38  includes a belt connection  46  which is connected to the rear end of the belt  30 . A chain connector  48  extends from the rear face  40  of the sliding barrier  38  and is connected to the rear end of the chain  32 . 
   Chain  32  is trained around a chain drive sprocket  50  at the front of the material spreader  10 . Sprocket  50  is mounted for rotation about a horizontal axis. A belt roller  52  is mounted at the rear of the material spreader  10  and is adapted for rotation about a horizontal axis parallel to the horizontal axis of sprocket  50 . The belt/chain assembly is trained around sprocket  50  and roller  52 , with the chain being engaged with the sprocket  50  and with the belt  30  being trained around the roller  52 . A material load  54  is deposited within the spreader box  12 . 
   A pair of gate lifting cylinders  56  are attached at their lower ends to the spreader box  12  at  60  and are attached at their upper end to an upper connection  62  on arms  58 . Each arm  58  is pivoted at its lower end about axis  65  and is rigidly connected at its upper end to gate  24 . Extension of this cylinder  56  causes the gate  24  to be lifted upwardly, thereby exposing the open rear end  18  which comprises a discharge end for discharging the material  54  within the spreader box  12 . 
   Mounted rearwardly of the gate  24  is a beater assembly  64  which includes a frame  66  and two or more rotatable shafts  68  on which are mounted beater bars  70  and flighting  72 . Adjacent the bottom of each shaft  68  is a rotatable bottom plate  74 . Each shaft  68  is attached to, and driven by, a hydraulic motor  76 , and each bottom plate  74  includes a plurality of spreader flanges  78 . The hydraulic motors  76  rotate the shafts  68 , and cause the flightings  72 , the beater bars  70 , and the spreader flange  78  to rotate and to engage the material exiting from the discharge opening  18 . The material as a result of this rotation is spread rearwardly from the material spreader. Motor  76  drives the left shaft  68  (as viewed in  FIG. 5 ) in a clockwise direction as indicated by arrow  94 . The other motor  76  drives the right shaft  68  in a counterclockwise direction as indicated by arrow  96 . Assembly  64  also includes opposite lateral wings  98 ,  100  ( FIG. 5 ) which are pivotally mounted so as to adjust the spread pattern of material  54  exiting from assembly  64 . 
   A hydraulic motor  80  is mounted adjacent the front of the spreader box  12  and drives the chain/sprocket assembly  28  by rotating the sprocket  50 . The result of this driving action is that the belt  30  and the sliding barrier  38  are moved rearwardly from their initial position shown in  FIG. 2  toward the intermediary position shown in  FIG. 3 . Ultimately the barrier  38  moves completely to the rear of the spreader box  12 , thereby discharging all of the material within the spreader box  12 . The belt  30  and the chain assembly  28  can then be retracted to their position in  FIG. 2  at the end of the cycle. The belt  30  covers the complete bottom wall  20  to the rear of barrier  38 . That is, belt  20  spans the width of bottom wall  20 , and also spans the length of wall  20  rearward of barrier  38 . The edges of belt  30  fit within grooves  82 . Thus the belt  30  underlies and supports the material  54  and carries it toward the open rear end  18  of box  12 . Prior designs must either push or drag the material  54 . Using belt  30  reduces the amount of power required to move the material  54 . 
   During this motion it should be noted that the chain  32  never encounters the material within the material spreader. Only the belt encounters the material. Thus if repairs are necessary to the chain, it is not necessary to remove the material from the spreader box  12 . 
   Furthermore, the belt  30  has its lateral edges guided in slots  82  ( FIG. 4 ). This ensures that all of the material is removed during the movement of the belt  30  and the sliding  38  to their rearward position. 
   Referring to  FIG. 6 , a modified form of beater assembly is designated by the numeral  84 . This beater assembly includes a plurality of horizontal shafts  86  which include beater bars  88  mounted thereon. A drive box  90  is driven by a hydraulic motor (not shown) to rotate the horizontal shafts  86 . A platform  92  is positioned below the horizontal shafts  86  for causing the material to be distributed rearwardly after being encountered by the rotating beater bars  88  on the shafts  86 . 
   Referring to  FIG. 7  a modified form of the beater assembly is designated by the numeral  100 . Beater assembly  100  includes a first auger  102  and second auger  104  which are upstanding for rotation in opposite directions. Auger  102  rotates in a clockwise direction where as auger  104  operates in a counter-clockwise direction. A first hydraulic motor  106  drives the auger  102  and second hydraulic motor  108  drives the auger  104 . Hydraulic motors  106 ,  108  are independently operated with respect to one another and include different hydraulic systems for driving them. 
   Each of the two shafts  102 ,  104  is rotated in upstanding position between a top frame  110  and a bottom frame  114  which are joined by two side frames  112  to create a rectangular opening  116 . 
   First auger  102  includes a first auger shaft  118  having a first flighting  120  helically extending thereon and second flighting  122  also helically extending thereon. The flightings  120 ,  122  are referred as to double flighting. It should note that the double flighting  120 ,  122  extends most of the length of shaft  118 , and there are no other breaker bars or beater bars mounted to the shaft  118 . Only the flighting  120 ,  122  is included. Mounted on the outer periphery of the flighting  120 ,  122  are a plurality of beater plates  124  which facilitate in the distribution of the material to be spread. At the bottom of shaft  118  are a plurality of radially extending fling plates which fling the material outwardly from the rear of the frame assembly  110 ,  112 ,  114 . 
   A second auger shaft  128  forms the central shaft for auger  104 . It includes a first flighting  130  and a second flighting  132  which are mounted the same as the flightings  120 ,  122  of first auger shaft  118 . However, they extend helically in the opposite direction. The reason for this is that the shafts  118 ,  128  are rotated in opposite directions and must fling the material rearwardly (toward the viewer as viewed in  FIG. 7 ). A plurality of beater members  134  are bolted on the outer edges of the helical flightings  130 ,  132 . At the bottom of shaft  128  are a plurality of radial extending fling plates  136 . 
   Referring to  FIG. 8  a schematic of the hydraulic and mechanical arrangement is shown. First and second motors  106 ,  108  are shown connected to first shaft  118  and second shaft  128  respectively. Motor  106  is connected to a hydraulic pump  138  and a tank  140  which are in a hydraulic system separate from that for driving motor  108 . Motor  108  is enclosed in a separate and independent hydraulic system comprising a pump  142  and a tank  144 . 
   A sensor  148  is connected to both motors  106  and  108  and is adapted to sense a build up in pressure in the motors  106 ,  108 . This pressure build up can occur when the feeding plate  160  feeds the material too quickly to augers  102 ,  104 . Sensor  148  is connected to motors  106 ,  108  by sensor connects  150 . A valve  152  is driven by sensor  148 . Valve  152  includes a valve spring  154  which biases the valve to a desired position. Valve  152  can be a continuous valve which continuously changes the hydraulic pressure provided to feed mechanism motor  156 . Motor  156  is mechanically connected to a sprocket  158  for rotating it in two opposite directions. The feed plate  160  is movable to increase or decrease the rate at which the material is fed to the hydraulically driven augers  102 ,  104 . A connecting gear  162  is connected to a chain  164  which extends around the sprocket  158 . Motor  156  is connected to a tank  166  which in turn is connected to a hydraulic feed mechanism pump  168 . 
   In operation, the hydraulic motors  106 ,  108  drive the auger shafts  118 ,  128  in opposite directions. As explained before, the hydraulic system and motors for operating shafts  118 ,  128  are independent and separate from one another. The sensor  148  senses a normal hydraulic pressure within motors  106 ,  108 , and also is responsive to sensing a build up of hydraulic pressure beyond the normal rate in either motor  106  or  108 . When such a pressure build up occurs, the sensor  148  causes the valve  152  to move either to its closed position or to move to an alternative position partially restricting the flow of fluid to motor  156 . This results in either slowing down the feed plate  160  or stopping it altogether. 
   Several things contribute to the low vibration that is created by the rotation of first and second augers  102 ,  104 . One of these features is the identical nature of the augers. Another feature is the use of double flighting. Yet another feature is the fact that the flightings extend the same distances on shafts  118 ,  128  and extend substantially the entire length. Maintaining the structure of the augers  102 ,  104  is possible to reduce the vibration caused by other auger configurations. 
   Also, other types of spreader attachments can be used in addition to the vertical and horizontal beaters. For example a side discharge expeller spreader attachment may be used without detracting from the invention. 
   Furthermore a cable and drum can replace the chain and sprocket assembly to accomplish the same result. A continuous belt may also be used. 
   While the drawings show a trailer mounted unit, the unit may also be truck mounted. The rate of discharge can be controlled by varying the hydraulic flow to motor  80 . 
   In the drawings and specification there has been set forth a preferred embodiment of the invention, and although specific terms are employed, these are used in a generic and descriptive sense only and not for purposes of limitation. Changes in the form and the proportion of parts as well as in the substitution of equivalents are contemplated as circumstance may suggest or render expedient without departing from the spirit or scope of the invention as further defined in the following claims.