Nurse adapter for air seeders

Abstract: A nurse adapter mechanism for an agricultural seeding implement converts an air seeder meter box into a nurse inductor box (20) to convey seed particles (S) to the singulator of a planting mechanism. The nurse adapter mechanism is detachably mounted on the meter box of the air seeder to receive a supply of seed particles therefrom and utilises the normal air flow (13) for the metering mechanism to effect a nursing of seed particles to a planting mechanism. The nurse adapter mechanism diverts the stream of air (13) into engagement with a pile of seed particles (S) and induce the entrainment of the seed particles for conveyance thereof to the remote planting mechanism. A partition wall divides the nurse induction mechanism into a seed side and an air side. The seed side receives the supply of seed particles from the hopper (12) and allows the seed to pass through a passageway into the air side for engagement by the stream of air. Divider walls (32) are provided to isolate each discharge tube from the other discharges tube so that the planter mechanisms can provide a continuous supply of seed particles. The discharge tubes (22) pass through the seed side of the nurse adapter mechanism in a stacked pair, modular configuration with the respective discharge tubes (22) being adequately separated to permit the passage of seed particles therebetween.

Description: This invention relates generally to air seeders for planting seeds in the ground in an agricultural environment and, more specifically, to a nurse inductor system cooperable with a planter mechanism to feed seed or other particulate material to a planting mechanism for insertion of that material into the ground. As the size of agricultural implements continues to grow, the versatility of such implements becomes more significant. Large air seeders have become increasingly popular for the planting of seeds, fertiliser and other product without strict regard for the exact placement of the seeds particles. For crop planting operations that require seed singulation nurse systems are used to feed seed or other particles from larger hoppers into smaller reservoirs located at the singulators. A nurse inductor system enables an air cart typically used for dry land farming, (cereal crops, etc.), to be adapted for use in row crop planting applications, such as corn and soybean, though not limited to soybean and corn. A nurse inductor system can be used to enable a farmer to singulate on-row, with one central hopper filling location, and to plant more acres before having to stop to fill the central hopper again, resulting in quicker planting and less labour, while maintaining the precision spacing available by on-row singulation. In U. S. Patent No. 5,161,473, a nurse system is disclosed which works off a specialised cart. The air comes into the seed delivery area coaxial with the seed tube that takes the air and seed to the row units. With this system substantial energy is used to nurse the seed since the air changes direction abruptly. This particular nurse system provides a dedicated fan to feed the 12 rows to be planted from the nurse system. This system requires the adding or removing of shims to adjust line length, which is difficult and inconvenient to accomplish. U. S. Patent No. 5,156,102 and U. S. Patent No. 4, 060,181 teach other nurse embodiments. It is further known from FR-2,591,416 to provide a detachable seed distribution unit for mounting on a mechanism having a hopper. The seed distribution unit communicates with a discharge opening from the hopper and intercepts a stream of air generated by the mechanism for creating a flow of air through the seed distribution unit. According to the present invention there is provided a nurse adaptor mechanism for detachably mounting on a hopper of a seeding mechanism having a supply of seeds and being operatively connected to a mechanism for creating a stream of air along a flow path, nurse adaptor mechanism comprises a housing adapted for detachable connection to said hopper characterised by a transverse partition wall separating a reservoir from a distribution apparatus, said partition wall defining a discharge opening at the bottom of said nurse adaptor mechanism for the flow of seeds there through into said distribution apparatus, a plurality of seed distribution tubes passing through said partition wall and through said reservoir for flow communication with a remote planting mechanism, each said seed distribution tube having an inlet opening in flow communication with said distribution apparatus and a plurality of generally vertically extending divider walls to isolate the inlet opening of said seed distribution tubes, said divider walls being sealed against said housing to define individual flow paths to each respective seed distribution tube wherein said stream of air is directed along a serpentine flow channel through said distribution apparatus into contact with seed particles flowing through said discharge opening, said stream of air passing through a nozzle creating a turbulence so as to entrain said seed particles and carry said seed particles into said seed distribution tubes for delivery to said remote planting mechanism. Said distribution tubes may be arranged in a generally vertically stacked configuration and may be sufficiently spaced to permit said seed particles to pass between said distribution tubes. Said seed may flow through said discharge opening to form a pile of seed particles oriented at a natural angle of repose. Advantageously, the area between the generally vertical divider walls may be greater than the cross-sectional area of the inlet openings of each respective said distribution tube so that the velocity of said air stream increases upon entering each distribution tube thereby allowing said entrained seed particles to be carried within said air stream until reaching said remote planting mechanism. The mechanism may further comprise a regulator to control the flow of seed particles through the discharge opening. The regulator may be formed by a moveable gate. The movable gate may extend across the entire width of the nurse adaptor mechanism and may be moveable by a single external handle. The mechanism for creating a stream of air along a flow path may be an air cart having a fan and a connection mechanism may be used to facilitate the connection of the nurse adaptor mechanism to the air cart as a modular component. The mechanism for creating a stream of air along a flow path may be an air cart having a fan and air delivery tubes and the nurse adapter mechanism may be operable to seal the air delivery tubes from the air cart when it is fitted to the air cart. The preferred embodiments of the invention offer the following advantages: It is possible to use an existing air cart for nursing individual planter units in a passive manner. Replacement of existing components on a conventional air cart with nurse induction components is sufficient to convert the standard air cart without requiring permanent modifications to the cart. The induction of seed or other particulate product is accomplished more evenly and consistently, thereby reducing the possibility of plugging of the lines. Bridging in the hopper side of the induction unit is avoided by increasing the room for particulate material to flow. The air pressure and flow required by the nurse induction system is reduced so that the existing fan on an air cart can be used for both nurse induction of seeds and the application of particles from one or more other air cart hoppers at the same time. The nurse inductor mechanism can be used on an air cart that may also be used in dry land farming. An adapter mechanism can be mounted on a conventional air cart in place of a conventional meter mechanism to convert the air cart into a nurse inductor apparatus. The adapter mechanism utilises the conventional air source from the air cart without requiring a separate air flow mechanism. The nurse adapter mechanism can be installed on a conventional air cart hopper without requiring the entire meter box to be removed from the hopper. The use of a common air source enables the air cart to both nurse seed particles and meter fertiliser to a planting mechanism simultaneously. The invention will now be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side elevation view of a typical air seeder mechanism on which a nurse adapter mechanism incorporating the principles of the instant invention is mounted; Figure 2 is a schematic cross-sectional view of the nurse adapter mechanism depicted in Figure 1, the arrows depicting the direction of air flow through the mechanism; Figure 3 is an enlarged schematic cross-sectional view of the nurse adapter mechanism shown in Figure 2 to depict the flow of air and seed through the uppermost seed distribution tubes leading to the planting mechanism, the arrows depicting the direction of air flow through the mechanism; Figure 4 is an enlarged schematic cross-sectional view similar to that of Figure 3 except depicting the flow of air and seed through the lowermost seed distribution tubes to the corresponding planting mechanism, the arrows depicting the direction of air flow through the mechanism; Figure 5 is a perspective view of the divider wall portion of the nurse adapter mechanism to depict the divider walls separating the uppermost and lowermost seed distribution tubes; Figure 6 is a perspective view of the particle hopper side of the nurse adapter mechanism with the exterior induction box wall removed, the distribution lines being oriented in vertical pairs to leave open space between the lines for the particles to pass through; and Figure 7 is a perspective view of the outlet side of the nurse adapter mechanism seen from the exterior of the mechanism. Referring first to Figures 1 to 4, the principles of the nurse induction apparatus can best be seen. The nurse induction apparatus or nurse adapter mechanism is mounted on a conventional air cart and redirects the air stream 13 coming from the fan 11 in an air cart box into a path that leads through the nurse adapter mechanism 20. The air stream is guided into a nozzle region 30 that directs the air along a flow path that tangentially engages a pile of seed particles S exiting the opening 19 at the bottom of the seed hopper 12. The turbulence of the blast of air from the nozzle 30 loosens the seed particles from this assemblage of seed particles S exiting the opening 19 in the bottom of the seed hopper 12, entraining the individual seed particles into the air stream as it follows a path to the distribution tubes 22 above the seed particle pile. The individual seed particles remain suspended in the air stream where the air bleeds off and the individual seed particles fall by gravity into a second pile or mass at the planting mechanism. As best seen in Figures 3 - 7, the air stream 13 through the nurse adapter apparatus 20 is split at the general location of the seed particle mass at the bottom of the central seed hopper 12 on the air cart 10 into individual sections 31 that are isolated by generally vertical walls 32. Each individual section 31 leads to a different seed distribution tube 22 and, ultimately, to a different receiver header (not shown) and associated receivers ( not shown) on a remote planting mechanism (not shown). The nurse adapter mechanism 20 induces seed particles into the air stream when and where there is demand for the particles. The demand for particles is controlled by the level of product in each respective receiver on the output end of the seed distribution tube. When a seed receiver is full, air is restricted from escaping from the seed distribution tube by the massed seed particles within the seed distribution tube. As a result of the filled receiver which prevents the passage of air therethrough, the air flow and air velocity reduce due to increased pressurisation of the line. This resultant reduction in potential air pressure reduces the capacity of the flow of air to induce the seed particles into the corresponding seed distribution tube 22. Since the flow of air through the nurse adapter mechanism 20 is spread across the entire unit, the flow of air will tend to go to the lines that have open receivers because of the less airflow resistance. The divider walls 32, that separate the air and entrained seed particle flows to each respective seed distribution tube 22 are sealed such that air cannot get into the seed distribution tubes 22 downstream of the pickup area. The sealed vertical walls 32 also prevent cross over of air and entrained seed to different seed distribution tubes 22. This division of airflow enhances operation since each line is operable to run at different times, depending on demand as represented by the massed seed particles in the output end of the seed distribution tubes 22. The shape of the air and entrained seed particle flow path has an impact on the performance of the inductor. When a receiver is filled to allow only a small volume of air to flow through the receiver, air alone is still capable of travelling through the lines, through the massed seed particles and past the seed particles at the vent. If seed particles were to be allowed to be induced into the lines with airflows that are less than carrying velocity, a blocking of the seed distribution tubes 22 can occur. This problem of blocking the seed distribution tube 22 can be avoided by forming the portion of the inductor structure, just above the area adjacent to the bottom of the central seed hopper where the individual seed particles are entrained into the airflow, larger so that the air velocity slows down in this region. With the slowed air velocity, any seed particles that had been entrained into the slow flowing air stream fall out of the airflow and are dropped back into the seed particle mass region. Thus, the seed particles are picked up and carried by the air stream only when the air velocity is above the minimum carry velocity, thereby allowing air to be flowing slowly without transporting any entrained seed particles into the full seed distribution tube. Correspondingly, the cross- sectional area of the seed distribution tubes is smaller than the cross-sectional area between the generally vertical walls dividing the plenum into discreet channels. As a result, the air velocity increases once entering the seed distribution tube, allowing the seed particle to be retained within the air stream once it enters the seed tube. The regulator 25 for the flow of seed particles into the area for entrainment within the air stream is defined by a movable gate 29 forming a common edge along which seed particles flow into the particle pick-up area. The product regulator 25 extends across the entire nurse adapter mechanism 20. As the seed particles flow under the product regulator, the seed particles form a pile falling naturally at the angle of repose of the seed particles. The angled surface of the pile of seed particles forms the bottom wall of the air channel in the pick-up area. The proximity of the air nozzle 30 to the wall of product affects the amount of product carried in the air stream. As the regulator 25 is rotated and more or less product is permitted to pass through the opening 19 at the bottom of the central seed hopper 12, the seed particles fall either closer to or farther from the air nozzle 30. Since different products, such as different seed types have properties that affect how easily the air stream picks them up, as well as the differences in the angle of repose at which the products slump, the ideal distance between the product surface and the air nozzle varies with the product being distributed. The product regulator 25 is adjustable to enable the optimum distance to be set for each product type, as well as the desired flow rate. As the air stream 13 strips the product away close to the bottom of the product regulator 25, product from the hopper 12 replenishes the created cavity. The closer to the bottom of the regulator 25 the product is stripped away, the more quickly the product is replenished. Thus, when the regulator 25 is positioned correctly for the specific type of product being nursed, the induction of product into the air stream is relatively steady. During testing, it was found that steady induction of product into the air stream reduced plugging problems within the distribution tubes 22 while maximising product delivery efficiency. The product regulator 25 is located on the hopper side of the induction box so that it does not interfere with the seal of the divider walls 32. The product regulator 25 is formed as a single crescent shaped plate 29 that extends across the entire width of the induction box of the adaptor mechanism 20. The regulator plate 29 is attached to a shaft that is rotated by an external handle 28. Thus, the flow of product across the induction box is controlled with the adjustment of a single handle 28. As a result, the flow rate of seed particles can be controlled for all of the tubes 22 simultaneously and can be completely shut-off to permit clean-out during which process the air will still be guided through the distribution tubes 22 without carrying seed particles. The rotatable regulator plate 19 can be adapted easily for remote control by appropriate actuators connected to the regulator 25. Such a configuration is particularly advantageous in precision farming practices, as the flow of seed particles through the seed distribution tubes 22 can be turned on and off easily. Alternatively, the regulator 25 could be configured to control the flow of air through the nozzle 30 instead of the flow of seeds. The generally vertical divider walls 32 are constructed such that the nurse adaptor mechanism 20 is made in pair segments that are stacked to fit the width of the induction box. The vertical nature of this modular design allows the inductor apparatus or adapter mechanism to be compact. The modularity of such a design allows the nurse adapter mechanism to be easily adapted to different widths and numbers of product lines, including a compact induction box width having a large number of product lines. To allow more space on the particle hopper side of the inductor unit, the distribution tubes 22 forming the outlet pipes are stacked in vertical pairs. The additional space between outlet pipes reduces bridging of the particles as they flow past the pipes and into the region of the product regulator 25. Each distribution tube 22 is independent. The walls 32 dividing the distribution tubes are curved to direct the air and entrained seed particle stream as shown in Figure 5. The air and entrained seed make relatively small directional changes in the inductor apparatus, which improves the efficiency of the air system. This efficiency enables both the nursing of more than 12 rows and the use of the second air cart tank for simultaneous fertiliser operations. Alternatively, the nurse adaptor mechanism 20 is adaptable for use with a stand-alone tank, as well as for with an air cart. Furthermore, the nurse induction unit 20 can also be adaptable to other planter units. As best seen in Figures 1 and 2, the nurse induction apparatus is preferably formed as a modular unit that can be inserted into a standard air cart structure to convert the air cart from a straight meter box into a nurse induction box. The conventional air delivery tubes 17 are sealed and remain on the air cart 10, while the nurse induction unit 20 is interposed to receive the air stream 13 from the fan 11. A connection mechanism 16 facilitates the convenient connection of the nurse unit 20 to the air cart 10 as a modular component. One skilled in the art will recognise that the instant invention is not limited to the conveyance of seed particles, as other particulate matter is commonly distributed through an air cart system, such as fertiliser. Furthermore, the typical air cart 10 is provided with multiple hoppers or tanks containing different product to be planted in the ground. One tank could have seed stored therein, while another tank would have fertiliser and yet another tank could have herbicides or still another reservoir of fertiliser. In such multi-tank configurations, one of the tanks could be provided with a nurse adaptor mechanism 20 to convey seeds to the planting devices, while a conventional meter box is used to control the flow of fertiliser or other product to the planting devices by separate distribution tubes. Such a conventional meter box could apply the fertiliser or other product at a variable rate and could be controlled by an electronic controller, as is known for precision farming techniques. Other alternative configurations can include one tank nursing seed to all the singulators, as well as multiple tanks nursing seeds to any one particular singulator. Therefore the nurse inductor apparatus or nurse adapter mechanism 20 enables the use of a standard air cart 10 for both the central hopper and the nurse system air source. The air cart fan can be used for both fertilising and nursing operations simultaneously. The nurse adapter mechanism 20 is designed in an adapter arrangement, which enables the air cart 10 to be readily converted from a roller type metering system to the nurse inductor system, and vice versa. The change to the cart to enable nurse induction is not permanent and does not require the use of time-consuming threaded fasteners.

Claims: A nurse adaptor mechanism (20) for detachably mounting on a hopper of a seeding mechanism (10) having a supply of seeds and being operatively connected to a mechanism (13) for creating a stream of air along a flow path, the nurse adaptor mechanism (20) comprises a housing adapted for detachable connection to said hopper characterised by a transverse partition wall separating a reservoir from a distribution apparatus, said partition wall defining a discharge opening (19) at the bottom of said nurse adaptor mechanism (20) for the flow of seeds there through into said distribution apparatus, a plurality of seed distribution tubes (22) passing through said partition wall and through said reservoir for flow communication with a remote planting mechanism, each said seed distribution tube (22) having an inlet opening in flow communication with said distribution apparatus and a plurality of generally vertically extending divider walls (32) to isolate the inlet opening of said seed distribution tubes (22), said divider walls (32) being sealed against said housing to define individual flow paths to each respective seed distribution tube (22) wherein said stream of air is directed along a serpentine flow channel through said distribution apparatus into contact with seed particles flowing through said discharge opening (19), said stream of air passing through a nozzle (30) creating a turbulence so as to entrain said seed particles and carry said seed particles into said seed distribution tubes (22) for delivery to said remote planting mechanism. A nurse adapter mechanism as claimed in Claim 1 wherein said distribution tubes (22) are arranged in a generally vertically stacked configuration and are sufficiently spaced to permit said seed particles to pass between said distribution tubes (22). A nurse adaptor mechanism as claimed in Claim 1 or in Claim 2 wherein said seed flows through said discharge opening (19) to form a pile of seed particles oriented at a natural angle of repose. A nurse adaptor mechanism as claimed in any of claims 1 to 3 wherein the area between the generally vertical divider walls (32) is greater than the cross-sectional area of the inlet openings of each respective said distribution tube (22) so that the velocity of said air stream increases upon entering each distribution tube (22) thereby allowing said entrained seed particles to be carried within said air stream until reaching said remote planting mechanism. A nurse adapter mechanism as claimed in any of claims 1 to 4 wherein the mechanism further comprises a regulator (25) to control the flow of seed particles through the discharge opening (19). A nurse adaptor mechanism as claimed in claim 5 wherein the regulator (25) is formed by a moveable gate (29). A nurse adaptor mechanism as claimed in claim 6 wherein the movable gate (29) extends across the entire width of the nurse adaptor mechanism (20). A nurse adaptor mechanism as claimed in any of claims 1 to 7 wherein the mechanism for creating a stream of air along a flow path is an air cart (10) having a fan (11) and a connection mechanism (16) is used to facilitate the connection of the nurse adaptor mechanism (20) to the air cart (10) as a modular component. A nurse adapter mechanism as claimed in any of claims 1 to 8 wherein the mechanism for creating a stream of air along a flow path is an air cart (10) having a fan (11) and air delivery tubes (17) and the nurse adapter mechanism (20) is operable to seal the air delivery tubes (17) from the air cart (10) when it is fitted to the air cart (10).

Inventors: ENGEN RONALD N, HUNDEBY DAVID R, MAYERLE DEAN J, ENGEN, RONALD N., HUNDEBY, DAVID R., MAYERLE, DEAN J.
Applicants: CNH CANADA LTD, CNH CANADA LTD.
Application year: 1999
Main classification: A01C7
IPC codes: A01C7