Abstract:
A dry inoculant dispenser includes a hopper with dry inoculant therein, and a conveyor for carrying dry product to a vertical drop tube. The drop tube is connected to a dispenser tube that will direct the inoculant to the forage material. A flow of air is created in the dispenser tube to carry inoculant therethrough, and a vacuum is created in the drop tube such that dry inoculant within the drop tube is sucked into the dispenser tube and dispensed from the distal end thereof.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
   (Not Applicable) 
   STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
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   INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC 
   (Not applicable) 
   BACKGROUND OF THE INVENTION 
   (1) Field of the Invention 
   The present invention relates generally to apparatus for mixing dry granular material uniformly with bulk materials, and more particularly to an improved apparatus for applying minute amounts of dry inoculant to large quantities of forage materials. 
   (2) Description of Related Art 
   Bacterial inoculant is applied to feedstuffs before ensiling, to improve the preservation efficiency of the ensiled crop. For forage crops, applying the inoculant at the cutter is the most efficacious method of application. 
   Inoculant can be applied in either a wet or dry condition. In a dry application, the bacteria are blended with a dry granular material and applied to the forage at the rate of ¼ pound to one pound per treated ton of forage. The most common method of application is the use of a granular applicator system such as that disclosed in U.S. Pat. No. 4,705,220. While this system clearly accomplishes its purpose of applying dry inoculant to a forage material, it has several drawbacks. First, the amounts of inoculant that must be applied require the user to handle hundreds or thousands of pounds of the materials each day. Such an amount is extremely labor intensive. However, attempts to use smaller amounts of inoculant in such a system produce variable inoculation rates, and therefore do not produce acceptable results. 
   Inoculants have also been applied in liquid form. Typically, dry bacterial concentrate is mixed with water and sprayed onto the forage. Application rates of one quart of liquid per ton of forage were common. As with dry applications, such large amounts of liquid products were very labor intensive. 
   Recently, a new applicator system that uses much less water (about 1.28 ounces per ton rather than a quart per ton) has been disclosed, in US Published Application 20030006312 to Dohrmann. While this new applicator is a vast improvement over prior art systems, there are still limitations. 
   First, some forage harvesters would prefer to not have to handle liquid inoculant in any manner. The difficulties and complexities of dealing with a liquid can be much greater than with a dry product. 
   Second, when dry bacteria are mixed with water, the inoculant must be used quickly, to maintain maximum viability. Thus, equipment breakdown, rain events, or even simply quitting for the evening, can all reduce the efficaciousness of the bacteria. 
   BRIEF SUMMARY OF THE INVENTION 
   It is therefore a general object of the present invention to provide an improved apparatus and method for applying small amounts of dry inoculant uniformly in forage material. 
   Another object is to provide a dry inoculant applicator and method that meters precise amounts of dry inoculant into an air stream, without “blow back” into the supply of inoculant. 
   These and other objects will be apparent to those skilled in the art. 
   The apparatus and method for applying dry inoculant to forage material includes a dry inoculant dispenser having a hopper with dry inoculant therein, and a conveyor for carrying dry product to a vertical drop tube. The drop tube is connected to a dispenser tube that will direct the inoculant to the forage material. A flow of air is created in the dispense tube to carry inoculant therethrough, and a vacuum is created in the drop tube such that dry inoculant within the drop tube is sucked into the dispenser tube and dispensed from the distal end thereof. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     The preferred embodiment of the invention is illustrated in the accompanying drawings, in which similar or corresponding parts are identified with the same reference numeral throughout the several views, and in which: 
       FIG. 1  is a pictorial view of a silage cutter with the applicator of the present invention installed; and 
       FIG. 2  is an enlarged schematic view of the applicator of the present invention with portions shown in vertical sectional view. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring now to the drawings, and more particularly to  FIG. 1 , the dry inoculant application system of the present invention is designated generally at  10 , and is shown installed on a self-propelled silage cutter  12 . System  10  includes an applicator designated generally at  14 , and an electrical control box  16  electrically connected to applicator  14  via wire  18 . 
   Cutter  12  is merely an example of one type of harvesting equipment upon which the system  10  of the present invention may be installed. Cutter  12  includes a cutting head  20 , which is shown cutting corn stalks  22  to create corn silage. Cutter  12  cuts and conditions the corn stalks  22 , or other similar material, and dispenses the conditioned forage material out spout  24 . A dispenser tube  26  extends from applicator  14  to dispense dry inoculant  28  to the cut forage material in cutter head  20 . It should be noted that the location of applicator  14  and dispenser tube  26  in  FIG. 1  is a matter of choice for the owner/operator of the equipment. The dry inoculant  28  may be dispensed onto the forage material at any desired location from cutting head  20  to spout  24 . 
   Referring now to  FIG. 2 , a schematic diagram of the dry application system  10  is shown. Applicator  14  includes a hopper  30 , which consists of an upright enclosed container  32  having a removable lid  34 . Hopper  30  holds the dry material  28  desired to be applied. As noted above, this dry material may be sugar plus dried bacterial culture. However, this applicator may also be used in other applications, wherein the dry material  28  may be a feed additive, a trace mineral, or any other similar dry products in dry powder or fine granular form that might be added to a total mixed ration for cattle, pigs, chickens or other livestock. In addition, the applicator system  10  of the present invention may be used in completely different fields of use, wherein a dry product is applied to a large quantity of material at a very low inclusion rate. 
   The lower end of hopper  30  includes inclined walls to form a funnel portion directing the dry materials  28  within the hopper to a lower outlet  38 . Outlet  38  communicates directly with an upstream end  40   a  of an auger  40  within a pipe  42 . The downstream or terminal end  40   b  of auger  40  communicates with the upper end of a vertical drop tube  44 . As shown in  FIG. 2 , the terminal end  40   b  of auger  40  extends beyond the wall of the drop tube  44  so that dry materials  28  do not accumulate at the end of pipe  42 . 
   A variable speed gear motor  46  is connected to auger  40  to selectively drive the auger  40  at a desired speed, to thereby dispense dry material  28  at a desired metered rate. While auger  40  is the preferred apparatus for moving the dry material  28  from hopper  30  to drop tube  28 , other apparatus could be used to perform this function equally as well. A conveyor is one example of such an apparatus. 
   Motor  46  is electrically connected to control box  16  via wire  18   a . Control box  16  is typically mounted within the cab of the harvester  12  (as shown in  FIG. 1 ) to permit quick and easy access by the user. Control box  16  is designed to allow the user to control the speed of motor  46 , so that the dry material  28  is metered out and applied at a desired rate of inclusion. The power source for application system  10  and control box  16  may be the vehicle to which it is attached (harvester  12 ), or from a standard electrical power source such as a battery or generator. A second wire  18   b  from control box  16  extends to a blower  48 , described in more detail below. 
   One of the important aspects of the invention is to provide a vacuum within drop tube  44 , so that air or other gas is not forced up the drop tube toward the hopper, and hampering or obstructing the metered flow of the inoculant or dry material  28 . In the preferred embodiment, the vacuum is produced by a venturi  50  formed within an injector housing  52 . Venturi  50  is formed by a tube with a short constricted section  50   a  and opposing widened tapered ends  50   b , such that air flowing through the constricted portion  50   a  at a higher velocity than through the tapered ends  50   b  creates a pressure differential in the constricted section  50   a . The lower end of drop tube  44  is connected to the constricted section  50   a  via an inlet port  54  in injector  52 , such that the pressure differential creates a vacuum within drop tube  44 . 
   An alternative to the venturi configuration of the preferred embodiment would be to position a blower in line with the drop tube  44  and dispensing tube  26 , where a vacuum exists on an upstream side of the blower and positive pressure is formed on the downstream side. Alternatively, some vehicles have a vacuum built into the machinery, such as the “blower” of a harvester, which could produce an adequate vacuum to dispense the dry material  28 . In such a case, one could simply attach a tube from the vacuum side of the blower to the dispensing tube  26 , to cause the dry material  28  to become entrained in the airflow and dispensed out dispenser tube  26 . Also, the injector housing  52  may not be required. 
   As noted above, the preferred embodiment of the invention uses a blower  48  to create the airflow through venturi  50 . Preferably, blower  48  is a centrifugal blower. However, an air compressor, or other source of pressurized gas could be used in place of blower  48 , depending upon the application to which system  10  is applied. All of these alternatives are envisioned with in the scope of the invention. 
   Dispenser tube  26  is preferably an elongated, flexible tube for carrying and directing the inoculant  28  to the forage material. In such an application, tube  26  would be about 1 inch in diameter and 10 to 15 feet in length. 
   Because of the vacuum applied to drop tube  44 , very small amounts of dry material, such as inoculant, may be uniformly dispensed from dispenser tube  26 . This permits the user to greatly reduce the effective inclusion rate over systems without this feature. In fact, the applicant has found that the system  10  can provide a uniform inclusion rate of about 2 grams of inoculant per ton of forage material, as compared with inclusion rates of about 113-454 grams per ton in prior art dry application systems. 
   Whereas the invention has been shown and described in connection with the preferred embodiments thereof, many modifications, substitutions and additions may be made which are within the intended broad scope of the appended claims.