Patent Description:
It is known from <CIT>, to provide an agricultural implement having a tongue, a central toolbar extending from the tongue, and first and second wings extending generally outwardly from the central toolbar. The implement further includes a central hopper system to provide the material to individual row units along the central toolbar and wings. A weight distribution system is used with the implement to update and adjust the amount of down force applied at the outer toolbars or wings, and the individual row units. The distribution system includes an intelligent control connected to sensors and cylinders. Therefore, the intelligent control receives information from the sensors and adjusts the cylinders accordingly to provide the appropriate amount of down force and to adjust the down force on a real time basis, and can be a closed loop or open loop system.

The invention provides an implement as defined by the subject-matter of independent claim <NUM>. Particular embodiments of the invention are defined in the dependent claims.

In one embodiment, the row unit may include a gauge wheel and a gauge wheel pivot pin configured to measure a reaction force at the gauge wheel from the ground surface and generate a signal indicative of the reaction force.

The control system might be programmed to compare the signal indicative of the applied force and the signal indicative of the reaction force to determine a force differential.

The row unit may further comprise a furrow opener configured to generate a furrow in the ground surface and a closing wheel configured to close the furrow in the ground surface, wherein the magnitude of the force differential is representative of a combined reaction force of the furrow opener and the closing wheel at the ground surface.

The magnitude of the additional force may be dependent upon the force differential.

Further, the control system might be programmed to apply the additional force to generate a reaction force at the gauge wheel at or above a predetermined reaction force.

In a further embodiment, the implement may comprise a product storage system mounted to the frame main section to carry the product, wherein the control system is adapted to operate the weight transfer system in a first mode and in a second mode. The control system might be operable in the first mode to reduce the weight transferred from the frame main section to the frame wing section via the weight transfer system in response to a decrease in a quantity of quantity of product in the product storage system. The control system might be further operable in the second mode to increase the weight transferred from the frame main section to the frame wing section via the weight transfer system in response to the signal from the sensor.

Further, the control system might be adapted to operate the weight transfer system in the first mode simultaneous with the second mode.

Other features and aspects of the disclosure will become apparent by consideration of the following detailed description and accompanying drawings.

Before any embodiments of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the accompanying drawings. The disclosure is capable of supporting other embodiments and of being practiced or of being carried out in various ways.

An implement <NUM> is shown in <FIG> as a row crop planter. Implement <NUM> has a frame <NUM> which includes a draw bar <NUM> and a tool bar <NUM>. At the forward end of the draw bar is a tongue <NUM> for coupling the frame <NUM> to a towing vehicle such as a tractor (not shown). The tool bar has a main frame section <NUM> and left and right frame wing sections <NUM> and <NUM> extending laterally from the frame main section. The frame wing sections are pivotally coupled to the frame main section for rotation about fore and aft extending axes <NUM> and <NUM>. The pivotal connection allows the wing sections to follow the ground contour as the machine moves through a field. Row units <NUM> are carried by the main frame section <NUM> and serve as main section ground engaging tools. Row units <NUM> are carried by the frame wing sections and form wing ground engaging tools. Generally speaking, the row units <NUM> and <NUM> are all identical but need not be identical. The row units will be described in more detail below.

A product storage system <NUM> is mounted to the frame main section and includes product bins or tanks, <NUM>, <NUM> and <NUM>. The bins hold seed that is delivered pneumatically to mini-hoppers on the row units. In other embodiments (not shown), the bins may hold dry or liquid fertilizer or water that used to dilute a concentrated insecticide or other chemical to be applied.

Main wheel assemblies <NUM> are coupled to the frame main section to support the frame main section for movement over a ground surface. Wing wheel assemblies <NUM> are coupled to the frame wing sections for supporting the frame wing sections for movement over a ground surface. Two wing wheel assemblies <NUM> are shown in <FIG>. Each wing wheel assembly <NUM> includes a tire and wheel <NUM> mounted to a support structure <NUM> for rotation on an axle <NUM>. The support structure <NUM> includes a mounting bracket <NUM> secured to the frame wing section <NUM> and a lift arm <NUM>. The lift arm <NUM> is pivotally connected to the bracket <NUM> by a pin <NUM>. The frame wing section <NUM> can be raised or lowered by operation of hydraulic cylinders <NUM> coupled between the lift arms <NUM> and mounting brackets <NUM> which are in turn secured to the frame wing section <NUM>. Both the rod end and the base end of each cylinder <NUM> are attached to the lift arms <NUM> and brackets <NUM> by pins <NUM>. The main wheel assemblies <NUM> have similar components as the wing wheel assemblies <NUM>, namely wheels and tires, lift arms and hydraulic cylinders. The main wheel assemblies will typically have components sized to carry larger loads than the wing wheel assemblies.

With reference to <FIG>, a row unit <NUM> is shown in greater detail. Row unit <NUM> includes a row unit frame <NUM> which is attached to the frame wing section <NUM> by parallel linkage <NUM>. Linkage <NUM> permits up and down movement of the row unit relative to the tool bar or frame wing section <NUM> to follow ground contours. Row unit frame <NUM> carries a double disc furrow opener <NUM> for forming a seed furrow <NUM> in soil or ground <NUM>. Gauge wheels <NUM> are provided on the sides of the two opener discs. The gauge wheels <NUM> function as furrow depth regulation members. Each gauge wheel <NUM> is respectively associated with one disc of double disc furrow opener <NUM>. More particularly, each gauge wheel <NUM> is positioned slightly behind and immediately adjacent to the outside of each respective disc of double disc furrow opener <NUM>. (The gauge wheels <NUM> can be placed in other locations relative to the opener discs if desired). The gauge wheels <NUM> are vertically adjustable relative to the opener discs to vary the depth of the furrow <NUM> which is cut into the soil by the double disc furrow opener <NUM>. Adjustment link <NUM>, pivotally mounted to the frame at pivot pin <NUM> locks into place and bears against the top of pivot arms <NUM> carrying the gauge wheels. The adjustment link <NUM> thus limits upward movement of the gauge wheels relative to the opener discs.

A seed meter <NUM> is also carried by row unit frame <NUM>. Seed meter <NUM> receives seed from a mini seed hopper <NUM>. Seed is delivered to the mini-hoppers from the product storage system <NUM> by a commonly known pneumatic distribution system, an example of which is shown in <CIT>.

The seed meter drive is not shown; numerous types of drive mechanisms are well known. Seed meter <NUM> delivers seeds sequentially to a seed tube <NUM> through which the seed falls by gravity to the furrow <NUM>. The seed meter <NUM> and seed tube <NUM> form a product dispenser to dispense product to the furrow <NUM>. A seed sensor <NUM> on the seed tube <NUM> detects passing seed as part of a monitoring system. The seed sensor <NUM> and monitor <NUM> can detect the product being dispensed. By combining the detected product dispensed with machine travel speed or position and time data, a product dispense rate is determined.

A pair of closing wheels <NUM> follows behind the gauge wheels and are positioned generally in line with double disc furrow opener <NUM>. Closing wheels <NUM> push soil back into the furrow <NUM> upon the seed or product deposited therein. Numerous types and styles of closing wheels or devices are known.

A supplemental down force system includes a row unit down force actuator <NUM> in the form of an adjustable pneumatic down force cylinder <NUM> on each row unit <NUM>. The cylinder <NUM> acts between the tool bar <NUM> and the linkage <NUM> to apply supplemental down force on the row unit and the row unit components engaging the soil. The supplemental down force applied by the cylinder <NUM> ensures that there is sufficient force to fully insert the double disc furrow opener <NUM> into the soil, forming the furrow <NUM> to the desired depth. The supplemental down force applied to the row unit by the cylinder is shown by the arrow FD. While only a down force cylinder <NUM> is shown in <FIG>, there may also be an up force, or lift cylinder. In other systems, there may be an adjustable mechanical spring providing a supplemental down force together with a pneumatic lift cylinder to fine tune the total down force. In such a system, the spring would be set to provide a down force that is greater than what is needed at any time and the lift cylinder would be controlled to counter-act a portion of the spring down force to produce a desire net down force on the row unit. A sensor or pressure transducer <NUM> is located at the down force cylinder <NUM> to measure the force applied by the down force cylinder <NUM> on the row unit <NUM>.

The row unit weight also produces a down force shown by the arrow FG acting through the center of gravity of the row unit. These two downward acting forces, FD and FG are counter-acted by upward forces acting on the row unit. The opener penetrates the soil and has a force FO acting upward on the opener. When the opener <NUM> is fully penetrating, the gauge wheels <NUM> will be in contact with the soil and a soil reaction force FR acts upward on the gauge wheels. An additional upward force on the row unit is the force FC acting on the closing wheels <NUM>. Other attachments to the row unit, not shown, such as a coulter or row cleaner will also generate an upward force on the row unit. In systems with an up force cylinder <NUM>, the supplemental down force FD, may at times be positive and at times negative, meaning it may be directed downward or upward, but is referred to herein as a "down force" regardless of direction.

A minimum soil reaction force FR acting on the gauge wheels <NUM> is desired to have confidence that the opener is fully penetrating the soil to the desired depth. If the soil reaction force FR acting on the gauge wheel is zero, the gauge wheel is not touching the soil. This only occurs when the opener is not fully penetrating the soil to the desired depth. Thus, some level of soil reaction force FR greater than zero is desired to be maintained to ensure there is full penetration by the opener. The magnitude of the force FR is measured by a sensor or load cell which can be placed in a variety of locations on the row unit. One example is a load sensor pin <NUM> in the gauge wheel depth adjustment link <NUM>. Adjustment link <NUM> bears against and resists upward movement of the pivot arm <NUM> carrying the gauge wheels <NUM>. A suitable load sensor pin is shown in <CIT>.

The load measured at the pin <NUM> is proportional to the soil reaction force FR, thus allowing the controller <NUM> to determine the soil reaction force at the gauge wheel <NUM> from the measured load. Load sensing pins may be provided at other points in the gauge wheel mounting and adjustment structure. Each row unit may be equipped with a gauge wheel load sensor pin <NUM> or only select row units may be so equipped. If only a few row units have gauge wheel load sensors, it is desired that there be at least one row unit on the frame main section and on a row unit on each frame wing section <NUM> with a gauge wheel load sensor.

The row units <NUM>, <NUM> are representative of row crop planter row units for planting seed. The implement <NUM> may have other types of seed planting row units or may only be for applying fertilizer or chemicals. Each opener will need to have sufficient down force to ensure the opener is fully penetrating the soil.

When the bins <NUM>, <NUM>, <NUM> are full, the weight on the frame main section and thus the main wheel assemblies is greater than the weight on the wing wheel assemblies. The greater weight on the main wheel assemblies can lead to increased soil compaction in the tire tracks of the main wheel assemblies <NUM> compared to the soil compaction caused by the wing wheel assemblies <NUM> and certainly more compaction than there is between row units where there are no wheel assemblies. Depending on the soil type and conditions, this increased compaction can result in lower yield from the rows adjacent the main wheel assemblies. To alleviate the effects of soil compaction, the machine is equipped with a weight transfer system to transfer weight from the frame main section to the frame wing sections in a first mode of operation. This spreads the weight of the implement over all the wheel assemblies to achieve a greater balance of loads on the wheel assemblies. Equal load on all wheel assemblies is not necessarily the goal as the main wheel assemblies may be larger than the wing wheel assemblies and able to carry a greater total load while producing the same soil compaction. As such, the goal in the first mode of operation is to achieve more load balance across the machine than if there is no weight transfer to reduce soil compaction caused by the main wheel assemblies.

The weight transfer system includes a hydraulic cylinder <NUM> connected between the main frame section <NUM> and each wing section <NUM>, <NUM> spanning across the wing pivot axes <NUM> and <NUM>. The right cylinder <NUM> is shown in <FIG> spanning across the pivot axis <NUM>. When the cylinder rod is extended, the cylinder <NUM> creates a clockwise moment about the axis <NUM> as viewed in <FIG>. This creates a greater up-force, or soil reaction force, on the wing wheel assemblies <NUM> and a corresponding decrease on the up-force on the main wheel assemblies <NUM>. The cylinder <NUM> could be mounted beneath the frame; in which case the rod is retracted to cause the weight transfer. Weight transfer of this type is known and is used on the John Deere <NUM> stack-fold planter and the Kinze <NUM> series and <NUM> series planters. These planters, however, have no means to control the weight transfer to ensure that the loads are more balanced across the implement wheel assemblies. The amount of weight transfer is manually determined by operator input and remains at a set amount until changed by the operator.

To provide for greater load balance across the implement, the wheel assemblies can be provided with load cells to measure the load on the tires and wheels <NUM>. The wheel assembly loads can be determined by a load cell at the axles <NUM>, the pins <NUM> attaching the lift arms to the mounting brackets <NUM> or the pins <NUM> at either end of the cylinders <NUM>. Suitable load sensing pins, bolts, etc. are available from Strainsert, Inc. of Conshohocken, Pa. The pressure in the wheel lift cylinders <NUM> can also be used to determine the load on the wheel assembly. A weight transfer control system operates the cylinders <NUM> to provide weight transfer to achieve greater balance of the soil reaction forces on the wheel assemblies. Only one wheel assembly on the frame main section and one wheel assembly on each frame wing section need to be equipped with a load cell to operate the cylinders <NUM> for weight transfer. However, all wheel assemblies can be so equipped if desired.

During operation of the machine, the product in the bins will gradually be applied to the soil or to plants, etc. and the weight on the main wheel assemblies will be reduced. The weight transfer control system will continually monitor the load on the wheel assemblies and adjust the amount of weigh transfer to maintain the improved load balance. The continuous monitoring of the wheel assembly loads enables feedback to the control system to make continuous adjustments in the magnitude of weight transfer.

The weight transfer can be controlled individually to the left and right wing sections to take into consideration weight differences between the two wings sections. For instance, if the machine is equipped with extendable row markers, the wing section with the row marker extended and in the ground will have a lower weight than the other wing section where the row marker is not extended.

The hydraulic system <NUM> for the weight transfer is shown in <FIG>. Valve <NUM> controls the flow of oil into and out of the cylinders <NUM>. When the pressure in the cylinder reaches the desired level, the valve closes, trapping the oil in the cylinder and maintaining the down force on the wing section. The valve <NUM> is a proportional electronic reducing/relieving valve. The valve pressure is variable and set by a DC current input. This input is varied by the weight transfer control system to produce the desired pressure in the cylinders <NUM>. As noted previously, the wing section is adapted to float on the ground. If the wing section travels over a low point, the pressure in the cylinder <NUM> will force the wing section downward to follow the ground, dropping the pressure in the cylinders <NUM>, causing the valve <NUM> to open and supply more oil to the cylinders. If the wing section travels over a raised terrace, the pressure in the cylinder <NUM> will increase, causing the valve <NUM> to open and relieve pressure enabling the wing section to float upward. Alternatively, the hydraulic system can employ an accumulator with pressure to act as a spring allowing the wing section to float continuously. While a single valve <NUM> is used to control both the left and right wing weight transfer cylinders <NUM>, separate valves <NUM> can be provided to separately control weight transfer to each wing section.

In place of actual measurement of the wheel assembly loading, other means can be used to approximate the wheel loading. For example, the bins <NUM>, <NUM>, <NUM> may be mounted on load cells to measure the weight of product in the bins. Suitable load cells are commercially available from Digi-Star Holdings, Inc. of Fort Atkinson, Wis. The weight transfer controller can determine the pressure needed in the cylinder <NUM> to transfer sufficient weight to substantially balance, or improve the balance of the loads on the wheel assemblies based on the machine geometry and the measured weight of product in the bins.

Bin level sensors can be used in place of bin load cells to determine the quantity of product in the bins. The product level and either actual density information input into the controller or an estimated density input can be used to determine the bin weight to use in calculating a cylinder pressure for weight transfer.

Heretofore, the weight transfer system has been described as using actual measured wheel loads or an approximation based on the weight of the product in the bins or an estimated weight of the product based on a bin level sensor. The weights or bin levels are continuous inputs to the control system for varying the weight transfer as the product is consumed. However, the weight transfer system could operate without any weight measurement or bin level measurement. When the operator fills the bins, he can input into the controller an estimate of the bin fill level. The product density can also be input to the controller. The density can be from typical density values for various products such as seed corn or bean seed, etc. or the product density can be measured by the operator and input into the controller. The controller can use this information to estimate the product weight and then calculate a desired pressure in the cylinder <NUM> to achieve an approximate balance across the wheel assemblies. By then using the seed sensor to count the seeds dispensed, the changing level of product in the bins can be continuously estimated. Other product dispensing sensors can be used to measure the rate of fertilizer or other chemical application. The calculated change in product in the bins can be used to continuously vary the amount of weight transfer to the frame wing sections.

In addition to balancing the load on the wheel assemblies across the machine, the weight transfer system can also be used to ensure the wing sections have sufficient weight for the row unit down force system in a second mode of operation. If the machine is working in hard soil, the static weight of the wing section may not be great enough for the pneumatic cylinders <NUM> to apply enough force FD to achieve the desire gauge wheel reaction force FR. In some instances, operators add iron weights to the frame wing sections to enable enough row unit down force. With the weight transfer system described above, weight can be transferred from the frame main section to the frame wing sections for row unit down force in a second mode of operation, even when weight transfer is not needed to reduce soil compaction in the first mode of operation. This can obviate the need to add iron weights to the wing sections.

The pressure transducer <NUM> is used to determine the need for weight transfer for row unit down force. The pressure transducer <NUM> measures the force FD that is transferred by the down force cylinder <NUM> from the frame wing section <NUM> onto the row unit <NUM>. In other words, the applied force FD is the force that is removed from the frame wing section <NUM> to drive the row unit <NUM> toward or into the ground surface.

In previous publications, namely in <CIT>, alternative systems are disclosed as being usable to determine the need for weight transfer for row unit down force. A first such system is the load sensor pin <NUM> in the gauge wheel depth adjustment link <NUM>. The load measured at the pin <NUM> is proportional to the soil reaction force FR, allowing the controller <NUM> to determine the soil reaction force from the measured load. However, the load sensor pin <NUM> does not measure the force that is applied by the down force cylinder <NUM>. Based on the location of the pin <NUM>, the pin <NUM> can only measure the reaction force FR of the gauge wheels <NUM>. The reaction force FR is only a component of the full force that opposes the applied force FD. Therefore, the force FO at the opening wheel <NUM> and the force FC at the closing wheel <NUM> can vary (e.g., due to soil conditions), yet these forces are not accounted for by the pin <NUM>.

A height sensor or position sensor on the linkage <NUM> is also disclosed in <CIT> as being usable to determine the need for weight transfer for row unit downforce. If the height sensor detects that the frame wing section <NUM> is too high off the ground, or the position sensors on the linkage bottom out, this information can be relayed to the controller <NUM> by a signal, and weight can be transferred from the frame wing section <NUM> to the row unit <NUM>. However, a height measurement determined by the height sensor does not account for the ground hardness and therefore is not representative of the applied force FD when one or more of the furrow opener <NUM>, the gauge wheel <NUM>, and the closing wheel <NUM> are in contact with the ground.

An example weight transfer control system <NUM> is shown in <FIG>. The control system includes a controller <NUM> including a micro-processor programmed for the function of controlling the weight transfer system. The controller <NUM> receives one or more load inputs from the load input box <NUM>. As mentioned before, the load inputs can include a main wheel assembly load sensor <NUM>. The load sensor <NUM> can be a wheel axle <NUM> load cell, or load cell on any of the pins <NUM> or <NUM> as described above. A similar wing wheel assembly load sensor <NUM> can also be provided. The load on the wheels can also be determined by the internal pressure in the wheel lift cylinder with a sensor <NUM>. The sensor <NUM> is likely a part of the hydraulic system. Other load sensors include the bin load cell <NUM> and the bin level sensor <NUM>.

The control system <NUM> also includes a display/user input device <NUM> which may be a touch screen, to allow the operator to manually input a bin level estimate as well as input a nominal density value for the product. The controller also receives an input of product dispensing from the seed sensor <NUM> and other product dispensing sensors. The seed sensor input will likely be aggregated data from the planter monitor <NUM>. The monitor also receives travel speed and/or position and time information from which product dispensing rates can be determined and a product dispense rate signal delivered to the weight transfer controller <NUM>. The controller <NUM> uses these inputs to determine the amount of weight transfer and then sends a command to a hydraulic controller to operate the weight transfer cylinders <NUM>. The physical architecture of the control system may vary from what is shown. For example, the controller <NUM> may be part of another system such as the planter monitor or the hydraulic controller, etc. Likewise, the display <NUM> may be used for other functions as well.

The control system <NUM> may also have an internal or external memory to record bin loads and the amount of weight transfer by location in the field. The location data is collected through a GPS or other positioning system now commonly used in precision agriculture. The data regarding bin loads and weight transfer can be used later and correlated with other field operations and subsequent yield data.

In the simplest form, for the first mode of operation, the weight transfer system uses operator provided information. When the operator fills a product into the bins, he then enters into the control system an estimate of how much product is in the bins, for example, to the nearest ⅛ of a bin. The operator also inputs the density of the product. The density can be from published tables for the particular product, or nominal values for the class of product. Alternatively, the operator can weigh a given volume of product, calculate the density and input that amount. The controller uses the estimate of bin fill and the density information to determine the product weight. This is added to the dead weight of the main section of the implement to determine the wheel load. With a known dead weight for the wings, the controller determines the amount of weight transfer needed to balance the implement load over all the wheel assemblies and the needed pressure in the weight transfer cylinders <NUM> to produce the desired weight transfer. As the implement is operated in the field, the controller uses dispense rate information from the seed sensors or other product sensors to determine how the product weight is changing. Other product dispensing systems may be programmed to apply product at a certain rate such as a certain number of gallons of chemical per acre. As the implement moves over the field, that information can be used to calculate a reduction in the quantity of chemical still in the bins or tanks. The controller uses the product dispensing information to continuously change the amount of weight transfer from the frame main section to the wings.

Greater precision is available with a measurement of the product in the bins. This can be done by a bin level sensor and user input data of the density. The bin level sensor can be used during operation to monitor the rate of consumption of the product and change the weight transfer accordingly. Still greater precision can be obtained by directly sensing the weight of the product in the bins or tanks with load cells on each bin and tank or by measuring the load on a main wheel assembly as described above. The change in this load over time is used to change the weight transfer. The greatest degree of precision is available from measuring the main wheel loads and the wing wheel loads. The weight transfer is then controlled to keep the desired loads on the main wheel assemblies and the wing wheel assemblies.

For the second mode of operation of the weight transfer system, to ensure that the row unit <NUM> on the frame wing section <NUM> is at a predetermined depth (e.g., the gauge wheel <NUM> is at a predetermined depth within the soil), the pressure transducer <NUM> measures the force FD applied by the row unit downforce system and generates a signal indicative of the applied force FD. The control system <NUM> operated the weight transfer system by actuating the hydraulic cylinder <NUM> in response to the signal from the pressure transducer <NUM> to assist the row unit downforce system. In other words, the row unit downforce system applies a downward force FD on the row unit <NUM> and the weight transfer system applied an additional secondary downward force FS on the row unit <NUM> via the frame wing section <NUM> to assist the applied force FD in driving the gauge wheel <NUM> and opening wheel <NUM> to and/or into the ground to the predetermined depths.

In order to determine the appropriate magnitude of the supplemental secondary force FS applied by the weight transfer system, the control system <NUM> also receives a signal from the gauge wheel sensor <NUM> that is indicative of the measured reaction force FR at the gauge wheel. The control system <NUM> compares the signals from the pressure transducer <NUM> and the gauge wheel sensor <NUM> to determine a force differential between the two forces FD, FR, respectively. The magnitude of the force differential is representative of a combined reaction force of the furrow opener <NUM> and the closing wheel <NUM> at the ground surface, offset from actual reaction force values by the weight FG of the row unit. The control system <NUM> determines the appropriate magnitude of the supplemental force FS applied by the weight transfer system based on the force differential. More specifically, when the force differential between the applied force FD and the reaction force FR is increased, the magnitude of the supplemental force FS is increased. When the force differential between the applied force FD and the reaction force FR is decreased, the magnitude of the supplemental force FS is decreased. At force differentials below a lower limit, the control system <NUM> determines that supplementary force FS is not necessary and the weight transfer system is not utilized to assist the row unit downforce system. The weight transfer system may still be operable in the first mode to limit compaction even if the force differential is below the lower threshold. Similarly, the weight transfer system may be operable in only the second mode, or in both modes simultaneously.

When the supplemental force FS is applied by the weight transfer system, the reaction force FR at the gauge wheel is at or above a predetermined threshold value to ensure that the furrow created by the furrow opener <NUM> and closed by the closing disk <NUM> is at an appropriate depth.

The implement may be operated in a manner that provides for a fixed portion of the total implement weight to be carried by the frame main section and the frame wing sections. For example, it may be desired that the frame main section carry <NUM>% of the implement weight while each of the right and left frame wing sections carry <NUM>% of the implement weight. After the main wheel assembly loads and the wing wheel assembly loads are determined, the weight transfer system transfers weight to the wings to achieve the desired weight distribution. During operation, the weight transfer is changed to maintain the desired weight distribution as the product in the product storage system on the frame main section is consumed.

The implement has been described in the context of a planter having a main frame section with laterally extending wing sections. The weight transfer system could also be adopted for use on an implement having a fore and aft arranged frame sections where only one frame section carries the load of the product storage system and it is desirable to transfer weight from one section to the other.

Claim 1:
An implement (<NUM>) comprising:
a frame (<NUM>) having a main section (<NUM>) and a wing section (<NUM>, <NUM>) pivotally coupled to the main section (<NUM>);
a main wheel assembly (<NUM>) coupled to the frame main section (<NUM>) to support the frame main section (<NUM>) for movement over a ground surface;
a wing wheel assembly (<NUM>) coupled to the frame wing section (<NUM>, <NUM>) to support the frame wing section (<NUM>, <NUM>) for movement over the ground surface;
a row unit (<NUM>) mounted to the frame wing section (<NUM>, <NUM>) to dispense a product to the ground surface; the row unit including a furrow opener (<NUM>) and a gauge wheel (<NUM>);
a weight transfer system coupled to the frame main and wing sections (<NUM>, <NUM>, <NUM>) and adapted to transfer weight from the frame main section (<NUM>) to the frame wing section (<NUM>, <NUM>) to reduce the load carried by the main wheel assembly (<NUM>), the weight transfer system including a hydraulic cylinder (<NUM>) connected between the main frame section (<NUM>) and each wing section (<NUM>, <NUM>) spanning across wing pivot axes (<NUM> and <NUM>);
a row unit downforce system coupled to the frame wing section (<NUM>, <NUM>) and adapted to apply a force on the row unit (<NUM>) relative to the frame wing section (<NUM>, <NUM>), the row unit including a row unit down force actuator (<NUM>) in the form of an adjustable pneumatic down force cylinder (<NUM>) on each row unit (<NUM>), the implement (<NUM>) characterized by further comprising:
a sensor (<NUM>) configured to measure the force applied by the row unit downforce system and generate a signal indicative of the applied force, wherein the sensor (<NUM>) is located at the down force cylinder (<NUM>) to measure the force applied by the down force cylinder (<NUM>) on the row unit (<NUM>); and
a control system (<NUM>) adapted to operate the weight transfer system in response to the signal from the sensor (<NUM>) to assist the row unit downforce system, wherein the control system (<NUM>) is programmed to actuate the weight transfer system to apply an additional force on the frame wing section (<NUM>, <NUM>) in response to the signal.