Patent Description:
Air carts are commonly towed by an agricultural tractor, to apply a material such as seed, fertilizer and/or herbicide to a field. An air cart is a wheeled cart which includes one or more frame-mounted tanks for holding the material. Air carts are also known as air seeders. In one embodiment of an air cart, the cart includes multiple separate tanks. In another embodiment the air cart includes a single tank having divided internal compartments. The air cart is typically towed in combination with a tilling implement, such as an air drill, one behind the other, to place the seed and fertilizer at or beneath the surface of the soil. Air carts include a metering system for dispensing material from the tanks and a pneumatic distribution system for delivering the material from the tanks to the soil. A fan provides at least one airstream which flows through the pneumatic distribution system. Material is first introduced to the air stream by the metering system at a primary distribution manifold located below the metering system.

The tanks of the air carts are formed with bottom surfaces that slope downward for the granular material to move toward the metering system. Gravity, in combination with the vibrations and movement of the air cart, acts to move the seed or granular material from the side or sides of the tank toward the metering system located toward the center of the tank. Material is moved by the air stream through distribution lines to a series of secondary distribution manifolds, which in turn distribute the material through distribution lines to material boots mounted behind ground openers on the tilling implement to evenly deliver the material, seed or fertilizer to the ground, which is tilled by the tilling implement.

Air carts typically deliver the material to one or more metering devices each including a roller section located within a housing having an input and an output. The material is delivered to a rotating roller having a plurality of chambers, each of which receives material at the input received from one of the tanks. As the roller rotates, each of the chambers receives a quantity of material. As the roller continues to rotate, each chamber deposits its quantity of material to the output which is delivered to one of the distribution lines.

As the roller rotates, material held in each of the chambers is released relatively rapidly under the influence of gravity. Because the material drops from its associated chamber relatively rapidly and while not instantaneous, the release of the material from the chamber appears as a pulse of material. No material or at least a reduced amount of material is dropped on either side of the pulse of material and consequently, the flow of material is not constant. The pulsing appears as a visible change in material flow exiting the chamber of the roller when the motor is spinning the metering roller at a constant angular velocity. Pulsing is more pronounced at low roller speeds, which correspond to low rates or low travel speeds of the air cart. Because of the pulsing effect, the material directed to the soil is not evenly applied. Such uneven application of material can reduce the quantity as well as the quality of the crop being grown. What is needed, therefore, is an air cart that deposits material, such as seed and fertilizer, at a relatively constant rate to improve crop production.

<CIT> discloses an air seeding system and method which includes a manifold mounted across a plurality of row planter units. Electric motors are mounted on the manifold and are operatively connected to the seed meters. A microprocessor or controller adjusts the speed of the motors in response to field data input so as to adjust the rate of seed dispensement to achieve desired plant population. The motor speeds can be adjusted on the fly, without stopping the air seeder. The system senses ground speed, senses the raised and lowered positioned of the row planter units, and senses any blockage of the row planter units. The motors eliminate the need for a ground drive wheel. However, the proposed air seeding system does not provide measures to compensate or minimize pulse of material.

According to the invention, there is provided a metering apparatus to deposit a material provided by an agricultural implement. The metering apparatus includes a motor drive having a drive input and a drive output, a motor including a spindle, a motor input operatively connected to the drive output, and a motor output. A metering roller is operatively connected to the spindle, wherein the metering roller is configured to deliver the material. A controller is operatively connected to the drive input and operatively connected to the motor output, wherein the controller receives a motor status signal from the motor output and transmits a motor drive signal to the motor drive to cause the motor to drive the metering roller at a variable rate to reduce variations in mass flow rate of the material being delivered.

In another embodiment, there is provided an agricultural implement to deliver defined portions of a material from a larger quantity of the material to a material depositing apparatus. The agricultural implement includes a tube defining a conduit having a first end, a second end, and an opening therebetween. A fan is operatively connected to the tube at the first end to deliver a flow of air through the conduit. A metering roller is disposed adjacently to the opening. The material depositing apparatus comprises a metering apparatus according to the invention.

The above-mentioned aspects of the present invention and the manner of obtaining them will become more apparent and the invention itself will be better understood by reference to the following description of the embodiments of the invention, taken in conjunction with the accompanying drawings, wherein:.

Corresponding reference characters indicate corresponding parts throughout the several view. The exemplifications set out herein illustrate embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

For the purposes of promoting an understanding of the principles of the novel invention, reference will now be made to the embodiments described herein and illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the novel invention is thereby intended, such alterations and further modifications in the illustrated devices and methods, and such further applications of the principles of the novel invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the novel invention relates.

<FIG> is a side elevational view of an agricultural vehicle, and more particularly an air cart <NUM>, also known as an air seeder. Air cart <NUM> is towed by an air tool <NUM> with a portion of a rear hitch <NUM> illustrated in <FIG>. The air tool <NUM> in one embodiment is an air drill but can be configured differently in other embodiments. The air tool <NUM> is also known as a commodity cart. In one embodiment, the air tool <NUM> includes a planter and the air cart <NUM> can be used to refill mini-hoppers on the planter. Air cart <NUM> can also include a rear hitch allowing air cart <NUM> to be towed in front of, rather than behind, tilling air tool <NUM>. In different embodiments, the air tool deposits materials of different sizes and shapes.

While an air cart is described, the present disclosure is not limited to air carts and includes other types of agricultural implements, including but not limited to self-propelled nutrient applicators, planter-fertilizer systems, and seeding tools with onboard storage.

Air cart <NUM> includes a frame <NUM> which in turn includes front wheels <NUM>, rear wheels <NUM>, tank <NUM>, blower <NUM>, and auger <NUM>. In the illustrated form, the tank <NUM> includes three separate mini-tanks or compartments 24A, 24B, and 24C with each mini-tank or compartment containing a material that is to be deposited or placed into or on the soil. Some materials include, but are not limited to, seed, fertilizer, insecticide, and herbicide. Each mini-tank or compartment 24A, 24B, and 24C has a top lid <NUM> that can be opened to fill the mini-tanks 24A, 24B, and 24C with material and then closed.

Air cart <NUM> includes a pneumatic distribution system <NUM> for delivering the air-entrained materials to the soil where trenches or rows have been formed by the tilling implement <NUM>. Pneumatic distribution system <NUM> includes a metering system <NUM>, one or more blowers <NUM> and a plurality of air lines <NUM>, also known distribution lines. The metering system <NUM> dispenses material from the tanks 24A, 24B, and 24C into one or more manifolds <NUM> (see <FIG>) which directs the material into one of the plurality of air lines <NUM>, and from there the material is conveyed to the air seeder via a plurality of air lines <NUM>. Although the illustrated embodiment of <FIG> includes three air lines <NUM>, it is contemplated that in other embodiments, such as is illustrated in <FIG>, a corresponding number of air lines <NUM> is used to transfer material from the tanks <NUM> to the tilling implement <NUM>.

As illustrated in a schematic view of <FIG>, a depositing apparatus <NUM> is operatively connected to each of the tanks <NUM> of the air cart <NUM>. The tank containers are not shown. Each tank <NUM> is connected to a manifold assembly <NUM>. The manifold assemblies receive the commodity from metering rollers <NUM> (See <FIG>) and deliver it to one of several groupings of conveyance lines 36A, 36B, 36C, etc. Each manifold assembly contains a plurality of individual manifolds corresponding to the number of metering rollers <NUM>. Each individual manifold receives commodity from an individual metering roller and diverts it to one conveyance line from either 36A, 36B, 36C, etc. with louver <NUM> (See <FIG>).

<FIG> illustrates a section view of <FIG> taken along lines <NUM>-<NUM>. Each of the distribution lines <NUM> defines a channel through which the blowers deliver forced air and through which material is delivered by the manifold 58C to outlets <NUM> (See <FIG>) of the distribution lines <NUM>. The distribution lines <NUM> are supported by the frame <NUM> and the set 36B is located below the set 36A. Distribution line set 36A subtends the manifold 58C which includes individual mounting structures to each support one of a roller drivetrain <NUM>. As seen in <FIG>, eight (<NUM>) roller drivetrains <NUM> are supported by the single manifold 58C. Each of the roller drivetrains includes a motor <NUM> (See <FIG>).

<FIG> illustrates a sectional side view of the depositing apparatus <NUM> at the location of manifold 58C of <FIG>. The tank 24C is located above and connected to the manifold 58C (as shown in this figure) to illustrate the configuration of the roller drivetrains <NUM>, each of which includes one of the motors <NUM>. At the bottom of the tank 24C, an agitator <NUM> receives material from the tank <NUM> to agitate the received material for proper flow to the roller drivetrain <NUM>. The roller drivetrain, in addition to the motor <NUM>, includes a gearbox <NUM> operatively connected to a rotating spindle of the motor <NUM>. The gearbox <NUM> is operatively connected to a roller <NUM> located within a housing <NUM>. Material flows from the tank 24C through the agitator <NUM> and to an inlet <NUM> of the housing <NUM>. A shutoff is located at the inlet <NUM> of the housing <NUM> to either allow or to prevent material flow from the tank 24C to the roller <NUM>. In another embodiment, the spindle of the motor <NUM> directly drives the roller <NUM>.

The roller <NUM> receives material from the inlet <NUM> and rotates responsively to the gearbox <NUM> being driven by the motor <NUM>. Material is captured by the roller <NUM> as described later herein and deposited into a receiving portion <NUM> of the housing <NUM>. Depending on the position of a louver <NUM>, as further described with respect to <FIG>, the material falls under the influence of gravity into one of the distribution lines 36A or 36B. The material is then directed in the direction <NUM> by the appropriate blower, blower 26A or 26B, to the outlets <NUM> of the distribution lines <NUM>. The position of louvers <NUM> is adjusted by a linkage, which is operatively connected to each of the louvers <NUM> of <FIG>.

As seen in <FIG>, each of the rollers <NUM> for each of the roller drivetrains <NUM> are located in a generally cylindrical cavity (disposed longitudinally) of the housing <NUM>. The rollers <NUM> are illustrated as being sectioned between ends of the roller to illustrate a plurality of chambers <NUM> defined by a flute <NUM> located between the pockets <NUM>. After the material flows through the agitator <NUM>, each of the chambers receives an amount of material over a time period determined by the rotational speed of the motor <NUM> and the gear ratio of the gear box <NUM>. As one of the flutes <NUM> of one of the pockets <NUM> moves past an interior wall <NUM> of the housing <NUM>, the material located in the pocket <NUM> starts to fall. The material falls or drops from the cavity into a passage <NUM>, a material drop point that is defined by the location of the louver <NUM>. As seen in <FIG>, the louvers <NUM> are directed to the right and the material drops into one of the distribution lines 36A. If the louvers <NUM> are directed to the left, the material drops into one of the distribution lines 36B.

Each of the roller drivetrains <NUM> is operatively connected to a controller <NUM> as illustrated in <FIG>. The controller <NUM>, in different embodiments, includes a computer, computer system, or other programmable devices. In other embodiments, the controller <NUM> includes one or more processors <NUM> (e.g. microprocessors), and an associated memory <NUM>, which can be internal to the processor or external to the processor <NUM>. The memory <NUM> can include random access memory (RAM) devices comprising the memory storage of the controller <NUM>, as well as any other types of memory, e.g., cache memories, non-volatile or backup memories, programmable memories, flash memories, and read-only memories. In addition, the memory in different embodiments includes a memory storage physically located elsewhere from the processing devices, including any cache memory in a processing device, as well as any storage capacity used as a virtual memory, e.g., as stored on a mass storage device or another computer coupled to controller <NUM>. The mass storage device can include a cache or other dataspace which can include databases. Memory storage, in other embodiments, is located in the "cloud", where the memory is located at a distant location which provides the stored information wirelessly to the controller <NUM>. When referring to the controller and the memory <NUM> in this disclosure, other types of controllers and other types of memory are contemplated.

The controller <NUM> executes or otherwise relies upon computer software applications, components, programs, objects, modules, or data structures, etc. Software routines resident in the included memory <NUM> operatively connected to the processor <NUM>, or other memory, are executed in response to the signals transmitted to a motor drive <NUM>. The motor drive <NUM> receives control signals from the controller <NUM> and provides a drive signal to the roller drivetrain <NUM> based on the control signals provided by the controller <NUM>. The motor drive <NUM>, in one or more embodiments, generates a drive signal that includes a power component and a frequency component to drive the motor <NUM>. A spindle of the motor <NUM> is fixedly coupled to the metering roller <NUM>. In another embodiment, the controller <NUM> is configured to include the motor drive <NUM>.

The motor <NUM>, in different embodiments, is an integrated motor including a motor and a controller having control capabilities including a processor that includes one or more of an encoder, an amplifier, a controller, and a communication port <NUM> operatively connected to the controller <NUM>. The encoder is configured to identify a position of the spindle with respect to the body of the motor and to identify a speed or velocity of the spindle. The communication port <NUM> is configured to receive control signals from the controller <NUM> as well as to transmit status signals of the motor <NUM>. The communication port <NUM> includes a motor input and a motor output. In one embodiment, the motor input is configured to receive power and a spindle driving signal to control the rotational speed of the spindle. The motor output drives the spindle.

In one embodiment, the motor <NUM> includes a velocity sensor to determine the rotational speed of the metering roller <NUM> and a position sensor to determine the position of the motor spindle, and therefore the metering roller <NUM>, with respect to the motor <NUM>. In one embodiment, the spindle, or shaft, includes a key configured to engage a receiving portion of the metering roller. When the key engages the receiving portion, the location of the spindle with respect to the motor is determined by the position sensor. The positional information of the position sensor is transmitted to the controller <NUM>.

In one embodiment, each of the motors <NUM> is controlled by a different AC signal. Each of the AC signals, operatively connected to each of the motors <NUM>, includes a sinusoidal waveform having a phase. In one embodiment, the phase of each of the AC signals are synchronized to be in phase. In other embodiments, the phase of each of the AC signals are synchronized to be out of phase, such that there is a phase difference between signals driving each of the motors. By staggering the phases between signals driving two or more or the motors <NUM>, peak power consumption is reduced. In addition, by staggering the phases, torque load is also reduced. By making the phases for each of the signals to be out of phase, the load provided by the motors, in different embodiments, is minimized.

As described above, each of the roller drivetrains <NUM> is located in a generally cylindrical cavity of the housing <NUM>. The housing <NUM> includes indexing features that orient the roller drivetrain <NUM> at a predetermined position, and therefore each of the motors <NUM> a fixed and known position within the housing <NUM>. By fixing the location of the motor <NUM> within the housing, the position of the dividers with respect to the housing is known and the position of each of the dividers <NUM> with respect to the interior wall <NUM> is known. Consequently, positional information of the dividers <NUM> and therefore the chambers <NUM> is identified by the positional sensor, and the rotational velocity information of the divider moving past the interior wall is also identified.

By use of the integrated motor <NUM>, precise control of motor speed is used to rotate the motor spindle to deliver product from the chamber <NUM>. The motor <NUM> is driven at a varying rotation speed as opposed to the normal convention of a constant speed. The motor <NUM>, and therefore the roller <NUM> delivers metered product in response to a time dependent or periodic control signal having two components: <NUM>) a non-varying amplitude portion which corresponds to a targeted rate or rotational velocity (for instance a DC signal), and <NUM>) a periodic signal portion with a frequency and a phase (for instance an AC signal) to reduce the pulsing effect currently associated with known metering designs. In different embodiments, the periodic signal includes a sine wave, a square wave, or a triangular wave signal. Other periodic signals are contemplated.

In a metering system having a constant velocity roller, the entire amount of material held in a chamber is completely released substantially all at the same time. This is known as pulsing. There are periods of material release separated by periods where little or no material is released. In the present disclosure, however, rotational speed of the roller is controlled using a motor controlled by a signal having a both frequency and amplitude component which reduces or substantially eliminates pulsing. The amplitude and phase shift of the periodic signal are determined such that the end result of the meter output is a reduced pulse effect (e.g. the amplitude (amount) of the released material is reduced) to the point where it is less noticeable, and in one or more embodiments no longer visibly detectable.

In order to determine the phase shift of the motor speed, the position of the roller relative to a material drop point and the positon of the divider with respect to the wall of the housing is determined. In one embodiment, the flow of material being released from a roller chamber is detected at an inlet to a cavity where the material is released. The detected material flow beneath the roller chamber provides an indication of when to speed up rotation of the roller and to slow down rotation of the roller. In one example, the roller is rotated slowly enough so that the sinusoidal pulses, which in one embodiment include sinusoidal pulses of an AC signal superimposed on a DC signal and which become a half-rectified sine way as the DC signal approaches zero. This effect occurs because the seed being deposited does not vacuum seed back into the meter. At this location, the flow sensor is used to determine the position of the flute. In another embodiment, the dividers (flutes) of the chambers dragging on the walls of the housing, are monitored to determine a torque signal. In this embodiment, the motor is configured to provide a torque signal to the controller <NUM>. In another embodiment, one of the flutes is made such that it extends past the other flutes to provide a higher drag, which when it crosses the material drop point would result in a reduction in rolling drag which can be detected by the motor <NUM> and transmitted to the controller <NUM>.

In another embodiment, a second sensor directly determines the position of the roller relative to the housing.

<FIG> illustrates a graphical representation of a metering device that does not include pulse compensation. In such an embodiment, a motor operatively connected to a roller is driven by a signal such that the roller is rotated at a constant speed <NUM>. In such an embodiment, the motor is driven by a signal having a constant amplitude, such as a DC signal. When the roller is driven at a constant speed, a pulsing condition of the material being deposited is shown by a variable rate line <NUM> that represents a pulsing of or a variable delivery of material from the roller. As the roller rotates a large quantity of material is released from the roller as shown by the maximum amplitudes of the line <NUM>. A small amount of material is released from the roller at the minimum amplitudes of the line <NUM>.

<FIG> illustrates a graphical representation of one embodiment of a metering device of the present disclosure having pulse compensation. The motor <NUM> is driven by a variable rate signal <NUM> having a sine wave configuration. When rotating the roller with the variable rate signal <NUM>, the pulsing condition of the material being deposited is substantially smoothed as shown by the signal line <NUM> that represents pulsing or a variable delivery rate of material being expelled from or deposited by the roller. By smoothing the pulsing condition of the material, variations in mass flow rate of the material being deposited is reduced.

To achieve the reduced pulsing of the material, the phase of the control signal <NUM> is adjusted to coincide with movement of the dividers moving past the sidewall of the material receiving chamber.

There are at least two methods for adjusting the phase shift of the motor drive signal. In a first method a mass flow sensor is employed in a feedback loop. The goal of the feedback loop is to obtain as close to a DC signal (a constant rate of material delivery) as possible (i.e. make the amplitude of the AC signal <NUM> of <FIG> constant). A second method employs a lookup chart contained within the controller <NUM>. In this example, the controller <NUM> determines the roller displacement and speed, and applies a phase shift to the signal, wherein the phase shift is determined by the controller using the lookup table. The frequency of the signal, and therefore the rate of depositing the material, is determined by roller speed and number of flutes. In another embodiment, the amplitude of the signal is adjusted within the aforementioned feedback loop.

<FIG> illustrates one embodiment of a metering device <NUM> configured with a conveyance tube selector within the meter housing. The metering device <NUM> includes a motor drivetrain <NUM> including an integrated motor <NUM> operatively connected to a gearbox <NUM> which is operatively connected to a removable roller <NUM>. The motor drivetrain <NUM> is supported by a housing <NUM>. The metering device <NUM> includes an adjuster <NUM> including a handle to manually adjust a positon of a louver, such as the louver <NUM> of <FIG>.

The roller <NUM> is removably replaceable with rollers of different configurations. For example as seen in <FIG>, roller 136A includes a cylinder <NUM> extending along a longitudinal axis of the roller. A portion <NUM> of the cylinder <NUM> of includes a first row of chambers <NUM> and a second row of chambers <NUM> located adjacently to the first row <NUM>. The chambers of the adjacent rows <NUM> and <NUM> are offset from one another such a divider of one chamber is disposed adjacently to a central portion of the adjacent. Each of the chambers is equidistantly and radially spaced from a central axis <NUM> of the roller 136A.

A roller 136B includes a first row of chambers <NUM> and a second row of chambers <NUM> located adjacently to the first row. Each row of chambers include <NUM> chambers and consequently, each of the chambers includes a sufficient volume to hold approximately 166cc. This size of chamber is adapted to deposit materials of a certain size. In one example of different sized rollers, roller 136A is for small seeds and fertilizers (~<NUM>), rollers 136B and 136C are the general use for most seeds and fertilizers, and roller 136D is for very high rates of seed or fertilizer or large seeds (<NUM> or more).

A roller 136C includes two rows of chambers similar to rollers 136A and 136B. In the configuration of roller 136C, the chambers are larger than the chambers of roller 136B. Likewise, the roller 136D includes two rows of chambers, each of which includes chambers larger that the chambers or roller 136C. Other sizes of chamber, other numbers or rows of chambers, and other radiuses of rollers are contemplated.

The delivery of material by each of the rollers 136A, 136B, 136C, and 136D is determined by a variable rate signal, such as the variable rate signal <NUM> of <FIG>. Each driving signal <NUM>, however, for each roller is determined based on the configuration of each of the rollers <NUM> of <FIG> and the speed at which material is delivered. For instance, the roller 136D includes larger chambers than the roller <NUM> B of <FIG>, and consequently the driving signal for roller 136D is different than the one for roller 136B in different embodiments. In one embodiment, the roller 136D is driven at a lower velocity than the velocity of the rollers 136A, 136B, and 136C to achieve the same mass flow rate.

Claim 1:
A metering apparatus to deposit a material provided by an agricultural implement (<NUM>, <NUM>), the metering apparatus comprising:
a motor drive (<NUM>) including a drive input and a drive output;
a motor (<NUM>) including a spindle, a motor input operatively connected to the drive output, and a motor output;
a metering roller (<NUM>) operatively connected to the spindle, the metering roller (<NUM>) configured to deliver the material; and a controller (<NUM>) operatively connected to the drive input of the motor drive (<NUM>) and operatively connected to the motor output of the motor (<NUM>), wherein the controller (<NUM>) is configured to transmit a motor drive signal to cause the motor drive (<NUM>) to drive the motor and to receive a motor status signal from the motor output of the motor (<NUM>), wherein the motor (<NUM>) in response to the motor drive signal is configured to drive the metering roller (<NUM>) at a variable rate to reduce a variation in mass flow rate of material being delivered, wherein the controller (<NUM>) includes a processor (<NUM>) and a memory (<NUM>), wherein the memory (<NUM>) has a plurality of program instructions that in response to execution by the processor (<NUM>) causes the controller to transmit a variable rotational velocity signal to the drive input of the motor drive to drive the spindle and the metering roller (<NUM>) at a variable rotational velocity during one revolution of the spindle, characterized in that the variable rotational velocity signal has two components, comprising a non-varying amplitude portion corresponding to a targeted rotational velocity and a periodic signal portion with a frequency and a phase.