Abstract:
A diffuser adapted to dissipate air from seed conveyed in a stream of air at a planter to an opener arm and seed boot. The diffuser provides a housing that pivotally supports a counter-weighted valve piece and a resilient valve piece. Admitted seeds are resiliently deflected between the valve pieces. Repeated deflections between the dual valve pieces and simultaneous venting of the conveying air through an associated fulcrum screen and relief ports at the housing dissipate the conveying air. Spent seed momentarily collects on a surface inside the housing and gravitationally falls from the housing and through a lower lying seed boot at a relatively uniform, singulated rate without scatter and damage to the seed.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to air seeders and, in particular, to a diffuser for reducing air pressure at the distribution point of an air seeder to substantially zero to gravitationally deposit seed at a uniform preset soil depth and seed spacing. 
     A wide variety of agricultural seeders have been developed for planting seeds in prepared soil. A common seeder type found at relatively large farm operations is known as an “air drill” or “air seeder”. Multiple openers (i.e. planting/fertilizing arms) are typically mounted to a tractor-towed framework. The openers are commonly supported at preferred row spacings to wings or arms that span multiple rows. The wings collapse (e.g. fold upward) to permit travel over roads and deploy from a collapsed travel condition to span the intended row spacing. 
     Each seeder typically provides an opener head or “seed boot arm” assembly to open and control the depth of each opened furrow. Associated controls and assemblies are included to clean each furrow (e.g. scraper member), tamp the planted seed (e.g. seed firming wheel), and close the furrow (e.g. packer wheel). The seed is dispensed from a covered hopper and an associated fan powered air distribution assembly. The seed is directed from the hopper, sorted and directed via appropriate conduits and tubing to individual distribution ports at relatively high pressures to dispense individual seeds in the prepared furrows. 
     A problem common to air seeders is that of delivering the seeds at relatively high air pressures and high velocities that cause the seeds to bounce in or around the furrows and/or out of the furrows and consequently produce inconsistent seed placement and germination. The seeds during delivery to the seed boot may also be damaged such that cracked or split seed may not successfully germinate. 
     One solution to the problem of which applicant is aware is promoted under the name “D-Cup Diffuser”. The diffuser provides a conical housing having an internal spiral passageway that tapers from a large diameter input port to a narrowed diameter outlet port. Air borne seed is tangentially directed into the passageway at the input port. The conveying air is dissipated to the atmosphere at the input end of the diffuser. The seed is directed down through the spiral passageway and falls from the outlet port. The air pressure is dissipated until the seed falls only under the force of gravity. 
     A problem persists if the seed boot plugs with mud, debris or other matter during difficult planting times as the seeds then tend to follow the air stream and blow out the top of the device and producing skips in the planted field. Even though seed hose monitoring devices exist that alert an operator to a plugged delivery line, the operator typically is not alerted with sufficient lead time to correct the plugged condition since seeds are still flowing through the air/seed hose. Instead of being deposited into the furrow, the seeds are broadcast onto the top of the soil. 
     The present invention was developed to provide an alternative air diffusion assembly to gravity dispense seed from an air seeder. The diffuser includes a formed, resiliently mounted first valve piece in a tubular housing to reduce initial seed velocity. The seed deflects from the first valve piece to strike an associated second resiliently mounted valve piece. A screen fitted into a bore of the housing supports and cooperates with the first valve piece to produce multiple deflections of the seed between the valve pieces as air pressure is bled off. The first valve piece is mounted to pivot from the screen member and includes counter weight and deflection arm portions. Ultimately, the seed falls under the influence of gravity through a dispensing port. 
     A projecting flange or ledge piece exhibiting a half-moon shape adjacent the dispensing port momentarily collects the spent seed. The spent seed tends to fall from the flange at a relatively uniform, generally singulated rate into a prepared furrow with a spacing determined by the operating ground speed of the dispensing port. The seed particularly falls into a prepared furrow at a predetermined depth optimal to the growth of the particular seed. 
     The relative displacement between seeds of the gravity placed seed assures a relatively uniform germination with less loss and damage to the seed. If wet and/or muddy conditions exist at the time of planting and a seed boot plugs with mud, grass, crop or surface debris or the like, the diffuser of the invention simply keeps seed from blowing from the included vents. A warning device alerts the operator to a plugged run earlier than with other devices which permits the operator to stop and clean the plugged condition to avoid further crop spacing skips in the field being planted. 
     SUMMARY OF THE INVENTION 
     It is a primary object of the invention to provide a device for diffusing or dissipating an air stream conveying seed to a seed planting boot to obtain uniform seed placement (i.e. spacing and depth). 
     It is a further object of the invention to provide a device for deflecting seed between multiple valve pieces and simultaneously diffusing or dissipating air conveying the seed as the seed is directed to a planting boot to obtain seed singulation (e.g. avoid double and triple seed placement especially for large seeds like sunflower and soybean seed). 
     It is further object of the invention to provide a housing that mounts to a seed conveying conduit containing valve members positioned to resiliently ricochet or deflect seed back and forth between the valve members as the seed is conveyed to an outlet port. 
     It is a further object of the invention to provide a housing containing at least one resiliently mounted valve member. 
     It is further object of the invention to provide a housing containing a counter weighted, pivotally mounted valve member. 
     It is a further object of the invention to provide a housing containing a counter weighted valve member mounted to pivot relative to a screen member. 
     It is a further object of the invention to provide a resiliently mounted or counter weighted valve member mounted to pivot relative to a screen member and deflect seed back and forth between the valve member and screen as air is dissipated from the housing. 
     The foregoing objects, advantages and distinctions of the invention are obtained in a diffuser assembly adapted for use with a variety of air seeders. In one construction, the assembly comprises a diffuser that includes one or more valve pieces resiliently mounted in the bore of a tubular housing to deflect seed in a fashion to dissipate the conveying air and gravitationally dispense spent seed. 
     In a presently preferred construction, the seed deflects from a first resiliently mounted valve piece to strike an associated second resiliently mounted valve piece. A screen fitted into a bore of the housing supports and cooperates with the first valve piece to produce multiple deflections of the seed between the valve pieces as air pressure is bled off. The first valve piece is mounted to pivot from the screen member and includes a counter weight arm and deflection arm. The second valve piece is mounted in the housing to resiliently flex upon seed impact. Ultimately, generally singulated seeds fall under the influence of gravity through a dispensing port into a prepared furrow at a relatively uniform spacing. 
     A variety of alternative configurations and combinations of features of the inventive diffuser can be developed. For example, a diffuser can includes one or more of the individual valve pieces or combinations thereof. Alternatively, multiple counter weighted valve pieces might be supported in the housing to deflect seed back and forth between the valve members. Alternatively, multiple resiliently mounted valve pieces might be supported in the housing to deflect seed back and forth between the valve members. Pivoting valve pieces might also be supported to pivot on structures other than a screen. 
     Still other objects, advantages, distinctions, constructions and combinations of individual features of the invention will become more apparent from the following description with respect to the appended drawings. Similar components and assemblies are referred to in the various drawings with similar alphanumeric reference characters. The description to each combination should therefore not be literally construed in limitation of the invention. It is also to be appreciated the singular improvements can be combined in any variety of track assemblies. The invention should therefore be interpreted within the broad scope of the further appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective view of the diffuser of the invention mounted to a planting head or seed boot assembly that is secured to a tractor drawn framework and fed with seed delivered from a hopper and one of several air/seed distribution manifolds and conduits that extend between the hopper, manifold, and a planting wing or arm to one of several seed boot delivery heads fitted to the wing assembly. 
         FIG. 2  shows an air/seed distribution manifold (shown foreshortened and in enlarged scale) that directs air borne seed via several supply conduits to each of several air diffusers of the invention only one of which is shown and which is mounted to the seed distribution conduit at a seed boot assembly. 
         FIG. 3  shows a side view to the diffuser oriented to depict the internal valve pieces and a support screen fitted within the housing and shown in dashed line relative to seeds being deflected back and forth between the valve pieces within the housing bore as air is dissipated through side wall air exhaust ports and spent seed is dispensed from a distribution port adjacent a projecting collection flange exhibiting a half-moon shaped shelf. 
         FIG. 4  shows a perspective view in exploded assembly to one of two housing pieces which supports a forward mounted, pivoting, counter weighted valve piece that is mounted to pivot from a support screen of the diffuser. 
         FIG. 5  shows a perspective view to the second of the two housing pieces and a resiliently supported, deflection valve piece that is mounted to flex and deflect seed back and forth to the pivoting first valve piece. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With attention to the perspective view of  FIG. 1 , an air drill diffuser  10  of the invention is shown as it appears when mounted to a typical tractor drawn air drill assembly  12 . The air drill assembly  12  typically includes a trailer storage bin  14  having fertilizer and seed compartments or hoppers  16  and  18 . The seed is delivered from the seed compartment  18  to a primary air and seed distribution manifold  20  and conveyed as an airborne particulate through several feeder conduits  22  to a trailer drawn planter framework  24 . The framework  24  is typically mounted to follow the bin  14  and one or more arms or wing frames  26  are hinged to pivot about the framework  24 . Multiple planter opener arm assemblies  50  having fertilizer and seed distribution ports in turn are supported to the wings  26 . The fertilizer is independently distributed from the fertilizer compartment or hopper  16  to a separate primary fertilizer distribution manifold  20  and separate feeder conduits  22  to the planter framework  24 . 
     The seed and fertilizer feeder conduits  22  extend along the planter framework  24  and the hinged wing frames  26  where the conduits  22  couple to lower ends of several secondary seed and fertilizer distribution manifolds  28 . The fertilizer and seeds are injected into the bores of “J-shaped”, tubular columns  30  at the manifolds  28  and subjected to contact with several dimpled protrusions  32  that project into the bore  34  of each column  30  to reduce the velocity and separate and agitate the fertilizer and seeds as the fertilizer and seeds rise in the columns  30 . 
     In particular regard to the seeds and after being agitated by the protrusions  32 , the seeds rise to a distribution head piece  36 . The head piece  36  contains a ring shaped separator having several vertical vanes. As the seeds rise in the bore  34  they are randomly distributed between the internal vanes. The vanes are aligned to associated outlet ports  42  formed at a rubber ring or seal piece  44  mounted in concentric relation to the internal vaned separator. 
     The primary flow of air and suspended seed is thus diverted into the ports  42  and associated seed delivery conduits  48  that extend to individual opener arm assemblies  50  that each support an individual planter head or seed boot. The opener arm assemblies  50  are supported to the wing frames  26  at an appropriate spacing set for the type of seed being planted. 
     Fertilizer is separately conveyed from other secondary distribution manifolds  28  to the seed boot of each opener arm assembly  50  and a prepared furrow. Each opener arm assembly  50  independently receives and dispenses an appropriate amount and type of fertilizer for the seed being planted. The air directed fertilizer is conveyed through a fertilizer conduit  52  to a distribution tube  54 , see  FIG. 2 . The fertilizer tube  54  is placed behind an opener head  56  which forms a planting furrow and into which the fertilizer is deposited to an appropriate depth. 
     A seed placement or planting head  58  is independently supported to each opener arm assembly  50  behind each opener head  56  and fertilizer distribution tube  54 . The depth of the head  58  is set to assure proper placement of gravitationally fed seed. Seed distributed by each secondary manifold  28  is conducted into and through the seed conduits  48  to the seed diffusers  10  of the invention and deposited from a seed placement boot  60 . 
     As the air and seed enter each diffuser  10 , the seed is caused to contact and ricochet or deflect back and forth between included valve pieces and the conveying air is simultaneously bled off. Ultimately the air is completely bled off and the seed collects and is momentarily supported on a seed support ledge  112  (e.g. half-moon shaped) inside the diffuser  10  before falling at a generally singular rate through the seed placement boot  60  under the force of gravity into a prepared furrow. At least one presser wheel  62  typically follows each planting head  58  to close each furrow over the deposited fertilizer and seed. The spacing between seeds is thereby primarily determined by the towed velocity over ground of each opener arm assembly  50 . 
     With the aid of the diffuser  10 , the air drill planting assembly  12  provides a relatively controlled, gravity placement of the seed without problems of seed fracture (e.g. cracking or splitting) and/or seed scatter. That is by dissipating the distribution air in the diffuser  10 , the seeds fall at a generally uniform rate and equal spacing to a pre-established depth for optimal soil/seed contact. Seed spacing is also dependent upon the towing speed of the opener arms  50 , while proper placement depth is established at the furrow opener  56  and mounting height of the seeder head  60  relative to opened furrows. The seed falls from the seeder head  60  and provides for a gravity distribution of the seed without bounce or scatter and unaffected by the distribution air. 
     With attention to  FIGS. 3 through 5  details to the construction applicant&#39;s diffuser  10  are depicted. The diffuser  10  is particularly shown in assembled and exploded assembly. Each diffuser  10  generally provides a tubular housing  70  constructed from two mating or overlapping side wall or shell pieces  72  and  74 . Rivets or other fasteners (not shown) secure the side wall pieces  72  and  74  together at tangs  76  that project from the shell pieces  72  and  74 . 
     Upstream/inlet and downstream/outlet ports  78  and  80  are configured and sized in the internal ends of the mated shell pieces  72  and  74 . The ports  78  and  80  interconnect and mate with specific seed conduits  48  (e.g. 1¼ or 1½ inch) provided at commercial planters  12 . The diffusers  10  are designed to mount as either before or after market accessories to each opener arm assembly  50 . Upon inserting the upstream and downstream cut ends of each conduit  48  into the ports  78  and  80 , the conduit  48  is gripped by several ringed ridges  82  or other devices to capture the diffuser  10  to the conduit  48 . The ports  78  and  80  and ridges  82  are sized and shaped to facilitate a secure fastening of the diffuser  10  relative to the operating environment and conditions. 
     Appropriate fasteners (e.g. screws) are also inserted through raised hubs  84  at the housing side wall  72  to secure the inlet and outlet ends of the diffuser housing  70  to the conduits  48 . Although one form of attachment and fastening of the housing  70  to the conduits  48  is shown, a variety of other couplings and fastenings can be used to physically secure each housing  70  to appropriate air and seed delivery conduits. 
     Mounted at the upstream or forward end of a cylindrical cavity, bore or channel space  86  within the housing  70  is a resiliently mounted valve piece  88 . The valve piece  88  is particularly hinge mounted. The valve piece  88  provides a leading seed deflecting arm portion  90  and a counter weight lagging arm portion  92 . The arm portions  90  and  92  extend at an angular orientation “A-A” in the range of 10 to 25 degrees relative to each other. An intermediate fold or bend  94  separates the leading and lagging arm portions  90  and  92  and permits the valve piece  88  to pivot at the fold  94  about a leading edge  102  of a screened fulcrum piece  96 . The length and weight of the lagging counter weight arm portion  92  relative to the leading deflecting arm portion  90  determines the degree of resilience exhibited by the valve piece  88 . 
     The angle “A” between the leading and lagging valve arm portions  90  and  92  is sized to provide free movement of the valve piece  88  as it pivots about the upstream edge  102  of the fulcrum/screen piece  96 . The fold  94  is supported on the edge  102  of the fulcrum/screen piece  96  and thus the lagging counter weight arm portion  92  is free to pivot about the edge  102  of the intermediate fulcrum/screen piece  96  in the space between the fulcrum/screen piece  96  and the internal surfaces of the side wall piece  72 . A stop member  103  projects interiorly from the shell piece  70  to limit the range of movement of the downstream end of the counter weight arm portion  92 . 
     The screened fulcrum piece  96  is constructed from a length of screen that extends in the cavity space  86  at an acute angle relative to the side wall piece  72  as the screen  96  projects downward toward the outlet port  80 . The upstream edge  102  of the fulcrum/screen piece  96  particularly extends from between lateral supports  98  that project from an interior surface of the side wall piece  72  in the cavity space  86 . 
     The fulcrum/screen piece  96  depends at an increasing angular orientation as it extends to rest on other downstream projections or supports  99  and a baffle or gate flange  100  adjacent the outlet port  80  of the cavity space  86 . The downstream edge  101  of the fulcrum/screen piece  96  is supported on the baffle flange  100  interiorly of the diametric center of the housing  70 , see  FIG. 3 . The baffle flange  100  also prevents seed from collecting behind the fulcrum/screen piece  96 . The fulcrum/screen piece  96  is typically mounted to extend at an acute angle in a range of 10 to 30 degrees relative to the side wall piece  72 . 
     Several longitudinal vents or relief ports  104  are let through the side walls of the shell piece  72 . The ports  104  extend longitudinally adjacent the counter weight arm portion  92  and fulcrum/screen piece  96 . Air entering the housing  70  with the seed is vented through the pores of the fulcrum/screen piece  96  and the ports  104 . The screen  96  presently exhibits a mesh or grit porosity in the range of 1/32 nd  (0.03125) to 5/32 nd  (0.15625) inch at each pore. Screening with other mesh or grit sizes can be used depending upon the seed size to prevent venting the seed from the housing  70  as the air is dissipated. If the screen pores are too small the pores will clog with fertilizer dust and not vent properly. Although the relief vents  104  presently only extend along the length of the counter weight arm portion  92 , more or less vents  104  can be provided and aligned as desired to the included valve piece  88  and fulcrum/screen piece  96 . 
     Returning attention to the upstream seed deflecting arm portion  90  of the valve piece  88 , it includes a secondary bend or downstream tail piece end  106  that extends into the bore of the cavity space  86  approximately to the diametric center. The tail piece  106  projects at an angle “B” in the range of 10 to 25 degrees from an upstream upper arm piece  108  of the seed deflecting arm portion  90 . The angles “A” and “B” are established to assure contact between the entering seed with the deflecting arm portion  90 . The relative angles “A” and “B” and lengths of the arm pieces  106  and  108  and valve arm portions  90  and  92  are established to provide a desired resilience at the hinged valve piece  88  to prevent damaging the seeds as they engage the valve piece  88 . 
     The type of material(s) from which the valve piece  88  and fulcrum/screen piece  96  are constructed is selected to withstand the abrading effects of the high velocity seed as it encounters the valve and screen pieces  88  and  96 . Although a counter weight arm portion  92  is provided and has proven effective, the material used to construct the seed deflecting valve piece  88  and fulcrum piece  96  can be selected and/or the valve piece  88  can be shaped to exhibit an intrinsic resilience. A resilient spring member may also be mounted between the arm portion  92  and the housing side wall  72 . Additional bends or resilient extensions may also be included at the seed deflecting valve piece  88  to provide desired seed deflection angles and resilience. Ideally the seed deflecting valve piece  88  is resiliently suspended in a fashion somewhat akin to a reed valve to avoid fracturing the seed as the air is vented from the housing  70 . 
     As described above the seed deflecting valve piece  88  and fulcrum/screen piece  96  are mounted to the longitudinal or side wall shell piece  72  of the housing  70 . With attention to  FIG. 5 , the adjoining side wall or shell piece  74  includes a second valve piece  110 . The valve piece  110  is also resiliently mounted and positioned like a second reed valve to deflect seed between the valve pieces  88  and  110  to dissipate energy. 
     A downstream portion  109  of the valve piece  110  extends at an acute angle “C” in the range of 10 to 30 degrees relative to the interior surfaces of the shell piece  74  toward the diametric center of the housing  70 . A downstream edge  111  of the second valve piece  110  terminates before intersecting the valve piece  88  and/or above the adjacent edge  101  of the fulcrum screen piece  96  and just short of the diametric center of the cavity space  86 . A gap is thus formed in the central region of the bore space  86  between the downstream edges  101  and  111  of the seed deflecting valves  88  and  110  and through which the seed falls after the air is vented. 
     A forward or upstream end  113  of the valve piece  110  is rigidly fastened to the side wall  74  and the unsupported downstream end  109  resiliently flexes in the housing  70 . The angular extension of the valve end  109  thus exhibits an inherent resilience. Seed initially deflected by the pivoting valve piece  88  upon entering the cavity space  86  is directed to impinge onto the second valve piece  110 . The flexion and angular orientation of the second valve piece  110  re-directs the seed back against the valve piece  88  or the fulcrum/screen  96 . The back and forth ricocheting effects of the valve pieces  88  and  110  and simultaneous venting of the conveying air completely reduces the velocity of the seeds such that the spent seeds generally exhibit zero velocity and gravitationally fall at a generally singular rate from the outlet port  80 . 
     It is to be appreciated the resilience of the valve piece  110  can be varied with different mountings or the use of different materials. The valve piece  110  might also be constructed of a porous material to vent air. The fulcrum piece  96  might also merely comprise a pivot member about which the valve piece  88  pivots. The counter weight arm portion  92  might also be mounted to deflect seed onto the valve piece  110 . 
     As the spent seeds pass the distal end of the fulcrum/screen  96  and downstream edge  111  of the second valve piece  110 , the seed momentarily falls to collect on a flange or ledge  112  that projects into the cavity or bore space  86 . The ledge  112  interrupts the seeds&#39; passage through the housing  70  and causes a small amount of seed to collect at the ledge  112 . The seed eventually randomly falls at a generally singular rate from the ledge  112  and through the seeder head or boot  60 . The displacement between the dispensed seeds generally depends upon the speed of the planter arm. A farmer is however assured that un-fractured seed is dispensed into and not outside the furrow. 
     While the invention has been described with respect to a presently preferred assembly and considered improvements, modifications and/or alternatives thereto, still other assemblies and arrangements may be suggested to those skilled in the art. It is also to be appreciated that the features of the foregoing diffuser housing assembly can be arranged in different combinations. For example, the valve pieces  88  and/or  110  can be constructed to provide a variety of different resilient mountings that promote deflection and energy dissipation. The foregoing description should therefore be construed to include all those embodiments within the spirit and scope of the following claims.