Abstract:
In an air pressurized system for use in delivering seeds in an agricultural planter from a main hopper to plural remote bins each associated with a respective seed discharge unit, an air/seed mixture is provided to a seed discharge unit via an air pressure dissipator which vents the air to the atmosphere in controlling the rate at which seed is delivered to the seed discharge unit. The air pressure dissipator includes an upper, angled tube having an outwardly tapered lower end adapted to receive an upper end of a perforated screen tube which extends into the seed discharge unit. As the seed discharge unit fills with seed during operation, the air pressure dissipator regulates the air flow entraining and transporting the seed by directing a portion of the air to the atmosphere when necessary to provide seed to the seed discharge unit to substantially match the seed discharge rate.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates generally to pressurized air systems for delivering seeds from a main hopper to one or more remote bins each as sociated with a planter row unit, and is particularly directed to an air pressure dissipator for regulating the flow of air and the amount of seed delivered to a planter row unit. 
       BACKGROUND OF THE INVENTION 
       [0002]    Early agricultural planters for simultaneously planting plural spaced rows of crops using seed metering apparatus for dispensing seeds at a controlled rate provided each seed metering unit with its own seed hopper. The limited space available along the length of the planter&#39;s tool bar restricted the size of the individual row unit hoppers and led to the use of a central seed hopper for supplying plural smaller remote hoppers, or bins, each associated with a respective row unit. Plural hoses, or tubes, connect the central seed hopper to each remote bin of an individual seed metering unit. The seed bin of a seed metering device is typically integrated in the housing of the seed meter. 
         [0003]    Air under pressure is used to move the seeds from the central seed hopper via the aforementioned tubes extending to the individual remote seed meters. Seeds in the main hopper are agitated by and entrained within an air stream and are delivered under pressure to the individual seed meters. In this type of distribution system, it is difficult to provide uniform seed agitation and transport via airstream entrainment to all individual remote seed meters to ensure uniform seed deposit in all of the crop rows. Inline air current which is too low will result in a reduced number of seeds being transported to the seed meters, while too high an air current may result in excess seed accumulation causing more than one seed to be discharged at a given time or interruptions in seed flow preventing deposit of seeds at regular intervals. Attempts to address this problem have led to the introduction of large remote hoppers having sufficient seed capacity to compensate for any reduction or interruption in the flow of seeds to any of the remote seed meters. But this approach has met with only limited success because of the limited space on the toolbar and the close spacings of the crop rows as discussed above. 
         [0004]    The present invention addresses the aforementioned limitations of the prior art by providing a means of variable air dissipation in a compressed air system for distributing seeds from one or more central hoppers to plural remote seed meters for timed deposit of individual seeds in the soil. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is an exploded perspective view of a planter row unit incorporating an air pressure dissipater for an air seed delivery sys tem in accordance with the present invention; 
           [0006]      FIG. 2  is a side elevation view of the inventive air pressure dissipater; 
           [0007]      FIG. 3  is an upper perspective view of an air dissipator tube incorporated in the air pressure dissipator of the present invention; 
           [0008]      FIG. 4  is a longitudinal sectional view of the air dissipator tube shown in  FIG. 2 , with a portion shown in enlarged detail; 
           [0009]      FIG. 5  is a bottom plan view of the air dissipator tube shown in  FIG. 2 , with a portion thereof shown in enlarged detail; 
           [0010]      FIG. 6  is a perspective view of a perforated tube assembly used in the air pressure dissipator of the present invention; and 
           [0011]      FIGS. 7 and 8  are side elevation views illustrating additional details of the perforated tube assembly shown in  FIG. 6 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0012]    Referring to  FIG. 1 , there is shown an exploded perspective view of an agricultural planter unit  10  connected to an air seed delivery system incorporating an air pressure dissipater  24  in accordance with the principles of the present invention. While the inventive air pressure dissipater  24  is described herein for use in a seed delivery system, this invention is not limited to one particular embodiment or to that type of environment and has application in virtually any particle, or particulate matter, delivery system using an airstream, or air (or other type of gas) under pressure, to move the particles. 
         [0013]    Planter row unit  10  includes a support frame  12  having attached to a lower portion thereof plural ground engaging tools  14  (only one of which is shown for simplicity) and wheels  16 . Also coupled to a lower portion of support frame  12  is an attachment mechanism  18  for connecting the planter row unit  10  to a toolbar (not shown) of an agricultural planter. Plural planter row units  10  are disposed in a spaced manner along the length of the toolbar. Disposed on and mounted to support frame  12  is a seed meter  20  which dispenses seeds in a timed manner as determined by the speed of the planter row unit  10  traversing a field. A lower portion of seed meter  20  is connected to a seed discharge tube  15  for discharging the seeds into a furrow formed by the aforementioned ground engaging tools  14 . The seed meter  20  shown in  FIG. 1  is of the vacuum type and includes an opening  20   a  to a seed reservoir within the seed meter. Attached to an upper portion of support frame  12  as well as to seed meter  20  is a seed meter mount  22  having an aperture  22   a  aligned with the aperture  20   a  in the seed meter. While the present invention is described herein as used in combination with a vacuum type seed meter, this invention could equally as well be used with a positive air pressure seed meter or a mechanical seed meter. 
         [0014]    Attached to an upper portion of seed meter mount  22  and aligned with the aperture  22   a  therein is an air pressure dissipator  24  in accordance with the present invention. A side elevation view of the inventive air pressure dissipator  24  is shown in  FIG. 2 . Air pressure dissipator  24  includes an upper air dissipator tube  26  or dissipater chamber and a lower air dissipator screen  28 .  FIG. 3  is an upper perspective view of the air dissipator tube  26 .  FIGS. 4 and 5  are respectively longitudinal sectional and bottom plan views of the air dissipator tube  26 , with each of these figures including enlarged portions of the air dissipator tube to illustrate additional details thereof.  FIGS. 6 ,  7  and  8  are respectively perspective and side elevation views of the air dissipater screen  28  of the inventive air pressure dissipater  24 . 
         [0015]    The air dissipator tube  26  of the air pressure dissipator  24  is preferably comprised of a high strength plastic and includes an upper angled portion  42  having an aperture  40  in the upper end thereof and a lower outwardly tapered portion  44  having a lower aperture  46  therein. The upper end of the angled portion  42  of the air dissipater tube  26  is adapted for coupling by means of plural spaced projections  52  on the outer surface thereof to a connector  30 . Connector  30  is adapted for coupling to a seed hopper by means of an elongated tube, which are not shown in the figures for simplicity. It is in this manner that seeds are provided from the hopper via the air pressure dissipater tube  26  to the seed meter  20  for deposit in the soil. A gasket  32  is provided between the upper end of air dissipator tube  26  and connector  30  for providing an airtight, sealed connection therebetween. The angle in the air pressure dissipator tube  26  is selected so as to facilitate seed/air flow through the air pressure dissipator  24  and to facilitate connection of the air pressure dissipator to a planter row unit disposed either forward or aft of the planter&#39;s tool bar by mounting the air pressure dissipator so as to extend either in a forward or an aft direction relative to the toolbar to accommodate the position of the planter row unit. In a preferred embodiment, the angle of the air pressure dissipater tube  26  is on the order of 45° to facilitate coupling the air pressure dissipater tube to a seed hopper typically via the combination of a flexible hose and a seed air entrainment device which are not shown for simplicity. While the present invention is described herein as being mounted to the top of the seed meter hopper and bent 45 degrees to accommodate hose attachment, this invention could work equally as well with other configurations, combinations and arrangements of its [principle] components. 
         [0016]    Extending downward from the angled portion  42  is the outwardly tapered portion  44  of the air dissipator tube  26 . Disposed on outer, opposed portions of the outwardly tapered portion  44  of the air pressure dissipator tube  26  are first and second mounting flanges  48   a  and  48   b . Each of the first and second mounting flanges  48   a ,  48   b  includes a respective aperture  50   a  and  50   b  therein. Each of apertures  50   a ,  50   b  is adapted to receive a respective connector  51   a ,  51   b  as shown in  FIG. 2  for securely connecting air dissipator screen  28  to a lower end of air dissipator tube  26 . In  FIG. 2 , first and second connectors  51   a ,  51   b  are shown as nut and bolt combinations, although various conventional types of coupling arrangements could be used to connect air dissipator tube  26  and air dissipator screen  28 . First and second connectors  51   a ,  51   b  may also be used to connect air pressure dissipator  24  to seed meter mount  22  such that air dissipator screen  28  is disposed within the seed meter mount&#39;s aperture  22   a  aligned with aperture  20   a  in seed meter  20 . Also disposed on the lower end of the outwardly tapered portion  44  of air dissipator tube  26  are plural spaced recesses  58   a - 58   d , where two of these recesses  58   a  and  58   b  are shown in  FIGS. 2 and 4  and all four are identified in  FIG. 5 . In addition, disposed about the inner surface of the air pressure dissipator  24  where its angled portion  42  meets its outwardly tapered portion  44  is a circular lip extension  54  extending in a downward direction as shown in the sectional view of  FIG. 4 . 
         [0017]    The air dissipator screen  28  attached to the lower end of the air dissipater tube  26  includes an elongated, linear perforated tube  72  preferably comprised of a non-corrosive metal, plastic or other suitable material. Perforated tube has an upper opening  72   a  and a lower opening  72   b  in its tapered lower end  72   c . Disposed about and attached to perforated tube  72  is a mounting plate  74 . Mounting plate  74  includes first and second opposed mounting flanges  74   a  and  74   b  each having a respective aperture  76   a  and  76   b  therein. Mounting flanges  74   a ,  74   b  and apertures  76   a ,  76   b  are aligned with the mounting flanges  48   a ,  48   b  and apertures  50   a ,  50   b  in air pressure dissipator tube  26  for connecting these two components together by means of the aforementioned first and second connectors  51   a  and  51   b . Formed integrally with mounting plate  74  and extending about the large aperture in the mounting plate is an upraised lip portion  74   c  which is crimped, bonded, welded otherwise attached to the outer surface of perforated tube  72  to securely connect these two components in a fixed manner. The openings along the length of perforated tube  72  allow air to pass through the tube, while maintaining seed entrained in the air flow from the main seed hopper confined within the air pressure dissipator  24  for delivery to seed meter  20 . 
         [0018]    While the lower tapered end  72   c  of the air pressure dissipator&#39;s perforated tube  72  is disposed within the seed reservoir in seed meter  20 , the upper end of the perforated tube extends into the outwardly tapered portion  44  in the lower end of the air dissipator tube  26 . The upper end of the perforated tube  72  defining aperture  72   a  therein is inserted in an annular slot  56  disposed between the above described inner lip extension  54  on the inner surface of air dissipator tube  26  and its outwardly tapered portion  44  as shown in  FIG. 4 . Contact is established between the upper edge of the perforated tube  72 , the inner surface of the outwardly tapered portion  44  and inner lip extension  54  of air dissipater tube  26  to ensure that none of the seeds escape the air delivery system and are directed through the perforated tube. As additional seed is deposited in the seed reservoir of seed meter  20 , the seed level approaches the lower end of the air pressure dissipator&#39;s perforated tube  72 . As the deposited seed fills the lower end of perforated tube  72  in an increasing manner, an increase in blockage of the openings in the perforated tube results thereby decreasing the amount of air that is discharged through the perforations in the tube, as well as through the plural recesses  58   a - 58   d  in the lower edge of the air dissipater tube&#39;s outwardly tapered portion  44 . This decrease in air discharged from a lateral portion of air pressure dissipater  24  reduces the air flow velocity in the seed delivery hose, thus preventing seeds from being entrained into the airstream and delivered to the seed meter until the seed level in the perforated tube  72  is lowered to permit additional air and seed to flow into the seed meter. Thus, as seeds are discharged to the soil, the seed level in the seed meter  20  drops allowing an increase in the air flow being dissipated to the atmosphere which in turn increases the air current in the seed delivery hose allowing additional seed to be entrained into the air stream and delivered to the seed meter for discharge onto the soil. It is in this manner that the inventive air pressure dissipator  24  operates to maintain the seed level in seed meter  20  at a more or less constant level to prevent the deposit of excessive amounts of seed in the seed meter, while ensuring a steady flow of seed to the seed meter for optimum seed discharge. While the present invention is described herein as having a straight perforated tube  72  used in conjunction with an outwardly tapered and angled dissipater tube  26 , other tube and screen shapes and combinations thereof could equally as well be used to create a variable air discharge area thereby controlling air current-dependent seed entrainment as seed levels rise and fall. 
         [0019]    While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the relevant arts that changes and modifications may be made without departing from the invention in its broader aspects. Therefore, the aim in the appended claims is to cover all such changes and modifications that fall within the true spirit and scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.