referring now to the drawings , and more particularly to fig1 - 3 , there is shown an agricultural application implement 10 , on which a pneumatic delivery system 100 can be used . in the exemplary embodiment shown , application implement 10 is a pneumatic granular fertilizer applicator 10 . as is known in the art , applicator 10 generally includes a large tired transport unit 12 such as truck or tractor , and laterally extending particle delivery booms 14 and 16 , which may be pivoted to a stowed position close to the implement for storage or transport . each boom 14 , 16 includes a plurality of boom tubes or conduits terminating at the outboard end in a particle delivering unit , which for fertilizer applicator 10 are a spreading outlet or nozzle . in the exemplary embodiment shown , boom 14 includes eight nozzles 18 , 20 , 22 , 24 , 26 , 28 , 30 and 32 ; and boom 16 includes nozzles 34 , 36 , 38 , 40 , 42 , 44 , 46 and 48 . additionally , at the back of applicator 10 there are rear nozzles 50 , 52 , 54 and 56 to provide full and complete coverage across the width of implement 10 , include the area between the inboard - most nozzles 18 and 34 of booms 14 , 16 . implement transport unit 12 is self - propelled by an engine in an engine compartment 58 and includes an operator cab 60 . in the exemplary embodiment shown , a tank 62 includes compartments 64 and 66 for carrying particulate material to be distributed to and disbursed by nozzles 18 - 56 . further smaller compartments 68 , 70 can be provided to supply micro - nutrients or other materials to nozzles 18 - 56 . the supply of particulate material in compartments 64 , 66 , 68 , 70 is replenished periodically from a still larger volume supply vehicle . fertilizer applicator 10 is illustrative of the types of equipment for which the pneumatic delivery system can be used ; however , it should be understood that the pneumatic delivery system may , of course , be employed in conjunction with other agricultural equipment such as tillage , seeding or planting devices , and is useful in distributing particulate material other than fertilizer . with reference now particularly to fig3 and 4 , in a simple form thereof , pneumatic delivery system 100 includes an inductor assembly 102 and a metering assembly 104 . inductor assembly 102 receives particulate material from tank 62 and supplies the particulate material to metering assembly 104 . metering assembly 104 distributes metered flows of the particulate material for distribution by nozzles 18 - 56 . inductor assembly 102 can be provided beneath tank 62 to receive particulate material from tank 62 under gravitational flow . inductor assembly 102 includes a pneumatic source , such as a fan 106 , an inductor 108 , an outlet conduit 110 from inductor 108 and a flow connection 112 to tank 62 . inductor 108 can be of known design and configuration , such as , for example and not limitation , that shown in u . s . pat . no . 7 , 182 , 029 “ inductor assembly for a product conveying system ” or that shown in u . s . pat . no . 8 , 534 , 208 “ product conveyance system for an agricultural implement ”. other types of inductors also can be used . those skilled in the art will readily understand the manner in which inductor assembly 102 produces a flow of air that combines with particulate material to generate a combined stream of forced air and the particulate material which is discharged through outlet conduit 110 . metering assembly 104 receives the flow of particulate materials from inductor assembly 102 and provides controlled , metered flow to the nozzles 18 - 56 by managing the air flow that controls particulate fluidization in the inductor , such as known for planters using a vacuum fan to control the quantity seeds going through the inductor . a seed gate also can be used to control fluidization . various types of metering devices can be used and can be carried by that portion of implement 10 which performs actual material distribution . accordingly , one type of metering device can be used when distributing particulate material of a first type and a different type of metering device can be used when distributing particulate material of a second type . it should be understood that separate and discrete inductors are provided for the number of compartments in tank 62 , with each such inductor having a separate outlet 110 there from to provide the particulate materials to metering assembly 104 . further , while fig4 shows a metering assembly 104 having a single unit distributing metered flow to each of the nozzles 18 - 32 on boom 14 , it should be understood that multiple metering devices within the metering assembly can be provided . fig5 schematically illustrates an implement 200 having a pneumatic delivery system 210 . implement 200 is similar to implement 10 , having a transport unit 212 and booms 214 , 216 . a tank 218 includes compartments 220 , 222 . pneumatic delivery system 210 includes an inductor assembly 224 having separate inductors 226 , 228 for compartments 220 , 222 , respectively . each inductor 226 , 228 has an outlet 230 , 232 , that is connected to each of a plurality of metering devices . boom 214 is provided with metering devices 234 , 236 ; boom 216 is provided with metering devices 238 , 240 and a rear metering device 242 is provided at the rear of a transport unit 212 . each metering device 234 - 242 receives particulate material flow from each inductor 226 , 228 . metering devices 234 - 242 each provide metered material flow to one or more particle delivery unit 244 , 246 , 248 , 250 , and 252 respectively . particle delivery units 244 - 252 can be nozzles as described previously or can be other types of delivery units such as rotating plates for the distribution of particulate material deposited thereon . the metering devices disclosed herein can be of various types . by way of example and not limitation , a metering device 300 is illustrated in fig6 . metering device 300 is provided for metering the flow of four particulate materials , such as may be included in a fertilizer and / or pesticide application . metering device 300 includes an individual accumulation hopper 302 , 304 , 306 , 308 for each particulate material that is being applied . hoppers 302 - 308 receive particulate material from inductors ( not shown ) by way of inductor outlet conduits 310 , 312 , 314 , 316 . each of the accumulation hoppers 302 - 308 is provided with an air breather 318 , 320 , 322 , 324 , respectively . as known to those skilled in the art , hoppers 302 - 308 provided with breathers 318 - 324 can operate with a pneumatic supply of material thereto in an on - demand fashion . as a particulate material accumulates in one of the hoppers 302 - 308 , the particulate material obstructs the breather 318 - 324 associated with the hopper , thereby stopping the flow of particulate material to the hopper . as the level of particulate material decreases in a hopper 302 - 308 , flow of particulate material thereto will resume . a vacuum inlet as known for planters also can be used . metered dispensing of particulate material from accumulation hoppers 302 - 308 can be by known means , such as a rotating metering roll 326 . in the exemplary embodiment shown , metering device 300 provides a combined flow of metered particles via a particle mixing drum 328 that receives the individual metered flows from hoppers 302 - 308 , mixes the particulate materials and dispenses the mixed materials to a rotary spreader 330 . the rollers can be separated by some minimal distance , or by a physical barrier or divider . since metered distribution of material continues even when the flow of particulate material to a hopper is interrupted , normal distribution of the material will continue until the hopper is empty , even if the upstream flow to the hopper is interrupted by plugging or the like . placing the meter at the end of the material conveying circuit , near the point at which the particulate material is applied , and separating the meter by way of the on - demand hopper system isolates the meter from changes in pressure upstream of the hoppers , such as may occur during temporary plugging and / or plug clearing . fig7 illustrates another metering assembly associated with a rotating applicator . carousel metering assembly 400 includes an array of individual metering devices 402 , 404 , 406 , 408 which may be compact individual metering units of various types , including rotating rolls , vibrating meters and the like . metering devices 402 - 408 individually dispense metered particulate material onto a rotary spreader 410 . metering devices 402 - 408 are supplied with a flow of particulate material via outlet conduits 412 , 414 , 416 , 418 , respectively . fig8 illustrates the use of five carousel metering assembly &# 39 ; s 400 each receiving particulate material from an inductor assembly 420 . meters can be driven individually by electric motors , hydraulic motors or the like ; or the meters can be linked together mechanically using a variable speed system of clutches , brakes and the like . while the pneumatic delivery systems disclosed so far herein have been primarily with respect to pneumatic fertilizer application equipment commonly referred to as a “ floater ”, it should be understood that the advantages from the pneumatic delivery systems disclosed herein can be obtained on other types of equipment for applying particulate materials in a field . planters of various types are known to include an applicator unit , such as a drill or seeder , and may include an air cart having one or more bulk tanks carrying fertilizer and / or seeds to be planted . the pneumatic delivery systems disclosed herein can be provided by way of one or more metering assembly on the planter , and one or more inductor on the air cart . if the air cart is then used with a planter of a different type , or with another type of particle application equipment , adjustments to the metering assembly can be made without the need to adjust the inductor assembly on the air cart . accordingly , switching from one crop to another crop or from one planter to another planter does not require major adjustment of the inductor assembly on the air cart . fig9 illustrates an agricultural application implement in the form of an air seeder 500 that includes an air cart 502 and an air drill 504 . air cart 502 includes inductors 506 , 508 , 510 to fluidize particulate material contained in each of three separate compartments . each inductor 506 , 508 , 510 is connected to each of a plurality of metering devices 512 , 514 , 516 , 518 , 520 . metering devices 512 - 520 meter seeds and / or other particulate material in controlled flows to pluralities of particle delivery units that deposit the seeds and / or other particulate material in the farm field . in using a pneumatic delivery system as disclosed herein , a variety of materials can be applied by a variety of different implements . the particulate material to be applied is contained in one or more compartments . the particulate material or materials are supplied to an inductor assembly wherein the material or materials are fluidized and conveyed to one or more metering device . at the metering device the conveyed product or products are provided in a metered flow and transferred to one or more particle delivery unit , which can be a broadcast spreader , seeder for depositing seeds or other materials across the surface of soil , a row opener unit for depositing seeds or other material in rows , or the like . when advantageous , the metered flows can be combined and the combined flow in appropriate proportions then provided to the particle delivery unit or units . while this invention has been described with respect to at least one embodiment , the present invention can be further modified within the spirit and scope of this disclosure . this application is therefore intended to cover any variations , uses , or adaptations of the invention using its general principles . further , this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims .
a pneumatic delivery system for particulate agricultural products includes one or more compartment for containing and supplying one or more particulate product . an inductor assembly separately receives and fluidizes the particulate products and conveys the fluidized products to a metering assembly . the metering assembly separately meters each of the product flows and transfers the metered flows to one or more delivery units for applying the products . the pneumatic delivery system can be used on various implements , including planters and applicators for applying seeds , fertilizer , pesticides and other products .