Patent Description:
Work machines, such as those in the agricultural, construction, and forestry industries perform a variety of operations. These work machines and implements have a need to adapt to changing environments. In some instances, work machines are row crop planters having row units configured to distribute a commodity to the soil and thereafter close the soil with the commodity therein. Typically row units include blades that form a trench area and a closing system that closes the trench area after the commodity has been distributed therein.

These work machines traverse uneven terrain that can include immovable objects, rocks, and holes which can cause a shock load or force on the closing system as the closing system traverses these elements. Moreover, soil properties can vary over a desired planting area that contains the uneven terrain. As the work machine traverses the desired planting area, the change in soil properties affects adequate and proper closure of the trench area with the commodity therein and presents a need to change how the trench area is closed and/or compacted. Some soil conditions and properties include type, texture, structure, porosity, chemistry, color, air content, that may affect the amount of force that the closing system needs to apply to the soil to properly close the trench area. For example, it is not desirable to compact the soil too tightly such that the seed has trouble growing through the compacted soil. It is also not desirable to have inadequate force on the trench area otherwise there will not be good commodity to soil contact.

For example, <CIT> discloses a seed coulter arrangement on a seeder. The seed coulter arrangement comprises a seed coulter for forming a furrow in a field soil and at least one pressure roller placed behind the seed coulter in the direction of operation of the seed coulter arrangement. The pressure roller is designed to roll with pressure on the soil. A coulter beam departing from a coulter frame is connected to the seed coulter and the pressure roller, whereby the pressure roller is arranged in an adjustable manner relative to the seed coulter by means of a parallelogram steering. Furtherm ore, an actuator element is provided for adjusting the parallelogram steering and for exerting a resulting movement of the pressure roller in relation to the seed coulter and a force determination device for detecting the force acting on the actuator element.

Furthermore, <CIT> discloses a down-pressure system for an agricultural implement has a linear actuator connected between a frame assembly and an opener assembly. A mounting structure for connecting the linear actuator to the opener assembly includes a bushing and an alignment member attached to the linear actuator. The bushing has protrusions extending transversely from opposite sides of a longitudinal axis of the linear actuator. Each protrusion has a curved engagement surface for engaging a flat surface on the opener assembly to prevent bending stresses on the linear actuator when the opener assembly is raised and lowered. The alignment member is arranged to lock the bushing into a predetermined rotational position about a longitudinal axis of the linear actuator relative to the opener assembly. The alignment member comprises a first structure that mates with a corresponding structure on the bushing, and a second structure that engages opposite sides of the opener assembly.

<CIT> discloses an agricultural soil rolling machine, the frame unit of which can be connected to the equipment connections of a tractor or carrier vehicle or to agricultural equipment which can be coupled or attached thereto. The frame unit can be connected in particular to an equipment for soil cultivation and seedbed preparation. The frame unit can transfer the weight of the tractor or carrier vehicle or agricultural implement, in whole or in part, to the rolling elements of the soil rolling equipment during rolling work.

Further, an agricultural material applicator is disclosed in <CIT>. The applicator uses a coulter, a knife, and a dual sealer assembly to provide agricultural material such as liquid manure to the soil. Weight of the agricultural material applicator is sup-ported by the sealer assembly to eliminate the need for addi-tional gauge wheels. The sealer assembly is two sealers pro-vided with independent suspension to allow one sealer to move out of the way of an obstruction, while the other sealer continues to operate.

Various closing systems for row crop planters can include automatic or manual adjustability to account for the changes in terrain and/or soil properties. Some closing systems that are adjustable rely on hydraulics and pneumatics, adjustment of motor speeds, adjustable air pressure from an air bag, spring system, or other techniques to adjust the amount of force on closing wheels of the row crop planter. A spring system is often used with the closing system wherein a spring is attached to a handle that is used to adjust or change the tension in the spring from a light force to a heavy or high amount of force on the closing wheels. However, this spring system does not adjust for the type of soil until the operator manually adjusts the tension setting for the spring. Other closing systems use different types of closing wheels such as wheels that flat roll the trench area, notched wheels, and/or wheels that are V-shaped. These wheels once attached to a row crop planter may not adequately account for variations in soil properties and terrain changes which may cause shock loading issues and inadequate contact between the closing wheels and soil due to the shock forces or variations in soil properties.

Such challenges create a need for more effective apparatus, systems, and methods for controlling adjustment of the closing system so that the closing system maintains optimal trench closing, especially while traversing uneven terrain.

The invention is defined according to claim <NUM>.

Further, a stroke length of the first actuator might be adjustable to thereby adjust the amount of the actuator force applied by the first actuator to the second actuator. Therefore, the first actuator might be adjustable to thereby adjust the amount of the actuator force applied by the first actuator to the one or more springs.

Each of the one or more springs ma have an initial spring stiffness, wherein increase of the actuator force to the one or more springs thereby increases the spring stiffness greater than the initial spring stiffness. The first actuator might be self-locking to maintain the actuator force on the one or more springs. Furthermore, an end plate might be positioned to block extension of the one or more springs beyond the end plate.

Referring to <FIG>, an exemplary embodiment of a row unit <NUM> that is configured for attachment to a rearward end of a work or agricultural machine such as a row crop planter. It is contemplated that a plurality of row units <NUM> would be attached to the agricultural machine however for ease of illustration only one row unit <NUM> is illustrated and described.

The row unit <NUM> includes a pair of linking arms <NUM> that are pivotally coupled at pivot <NUM> to a body portion <NUM>. The pair of linking arms <NUM> extend to a frame portion <NUM> configured for attachment to the rearward end of the work machine. The row unit <NUM> includes a shank <NUM> that extends away from the body portion <NUM>. The shank <NUM> is pivotally coupled at pivot <NUM> to a shank extension <NUM>. The row unit <NUM> includes a pair of gauge wheels <NUM> rotatably mounted on the body portion <NUM> and a pair of closing wheels <NUM> rotatably mounted on the shank extension <NUM>. The row unit <NUM> includes a closing wheel system <NUM> operably connected to the shank extension <NUM>, the shank <NUM>, and the pair of closing wheels <NUM>. A row cleaner is not illustrated but could also be mounted to the row unit <NUM>. The pair of gauge wheels <NUM> are coupled to and moveable vertically relative to the shank <NUM>. The pair of closing wheels <NUM> are pivotably coupled to the shank extension <NUM>. Although the pair of closing wheels <NUM> are illustrated in a V-shape configuration, in other forms, the pair of closing wheels <NUM> can have any shape that is known to close the commodity in a commodity trench.

The row unit <NUM> is configured to receive commodity, such as seed, from containers on the work machine and deliver the commodity to the soil. Once the commodity is delivered to the soil trench, the soil trench must be closed by the closing wheel system <NUM> to an optimal compactness to maximize crop yield, and therefore, each closing wheel system <NUM> should be maintained at a desired closer wheel downforce to close the soil trench in the ground with the commodity therein. Moreover, as the row unit <NUM> traverses uneven terrain such as rocks, holes, or ground undulations, a shock force or load is applied to the row unit <NUM>, however with an appropriate nominal force setting on the closing wheel system <NUM>, the closing wheel system <NUM> will overcome the shock force or load and thereby float along the ground undulations and rocks as these terrain features are encountered by the row unit <NUM>.

The closing wheel system <NUM> is one example however the present disclosure is applicable to other work machines where it is desirable to adjust a force with the ability to float and breakaway with ground undulations and rock strike while traversing a terrain. The closing wheel system <NUM> is a novel way of combining multiple actuators to both follow ground undulations and overcome shock loads to respond while providing a variable nominal force adjustment to the closing wheel system <NUM>. One of the multiple actuators is configured to absorb shock or force due to ground undulations, rock strike, or other forces caused while the closing wheel system <NUM> traverses terrain and another actuator of the multiple actuators is configured to adjust or shift the shock absorbance to either increase or decrease an initial or nominal amount of shock absorbance of the shock or force absorbing actuator. The actuator that is configured to absorb shock or force from the ground undulations can be adjustable, and can either be active or passive. In one form, the actuator that is configured to absorb shock or force is a passive mechanical device wherein the mechanical device is not operable by electric power. The multiple actuators are combined in series or parallel, and single or multiple sets of the multiple actuators are disclosed for the closing wheel system <NUM>. Some non-limiting examples of actuating devices that can be used for either adjusting a nominal force and/or absorbing shock force include gas shocks or gas springs which can be passive or adjustable. Other non-limiting actuating devices include a compliant material, such as rubber bumpers, bunge straps, which can be passive or adjustable. Other non-limiting actuating devices include a hydraulic actuator which can be active and adjustable, or a hydraulic actuator with an accumulator which can be active, adjustable, or passive (using accumulator). Other non-limiting actuating devices include a pneumatic air spring or shock or bag that can be active if the pneumatic air spring or shock or bag is coupled to an air source or air valve. The pneumatic air spring, shock, or bag is adjustable or can be passive due to the air compression. Some examples of actuating devices include mechanical springs which can include extension, compression, torsion, coil, leaf, and/or Belleville types. Some examples of actuating devices can include general shock absorbers including gas or coil over types. Some examples of actuating devices can include lead screw including passive or back-driveable, or active if powered by a motor. Some examples of actuating devices can include a ball screw that can be self-locking or active if powered. Some examples of actuating devices include memory material, such as spring steel or other material that deforms and returns to its shape when load is released, and can be passive.

The closing wheel system <NUM> includes a first actuator including a linear actuator <NUM> operably coupled to a second actuator including a pair of springs <NUM> stored in a spring housing <NUM>. The closing wheel system <NUM> includes a pair of spring rods <NUM> on which the pair of springs <NUM> respectively travel along. The pair of spring rods <NUM> are mounted, at least partially, in spring housing holes <NUM> in the spring housing <NUM> such that first ends <NUM> of the pair of spring rods <NUM> are attached to the shank <NUM> at pivot <NUM>. The pair of springs <NUM> include one or more mechanical springs. In the illustrated embodiment, the linear actuator <NUM> is positioned between the pair of spring rods <NUM> which results in a compact space saving system because each of the pair of springs <NUM> is adjacent the linear actuator <NUM> and utilizes space on the sides of the linear actuator <NUM> rather than in-line wherein the springs <NUM> are aligned with the linear actuator <NUM>. Beneficially, this arrangement of springs <NUM> adjacent or in series with the linear actuator <NUM> utilizes simultaneously the stroke length of the actuator <NUM> and the length of the springs <NUM>. Advantageously, the linear actuator <NUM> is electrically adjusted but the springs <NUM> are mechanically passive elements to absorb shock loads from ground undulations and rock strike. In other embodiments, the pair of springs <NUM> can be inside the linear actuator <NUM>. In other embodiments, only a single spring is used with the linear actuator <NUM>. In yet other embodiments, one or more springs are positioned linearly with the linear actuator <NUM>. In yet other embodiments, the linear actuator <NUM> and the pair of springs <NUM> can be replaced with any of the herein described actuators or other actuators as commonly known by a person of ordinary skill in the art.

The closing wheel system <NUM> includes an end plate <NUM> having a pair of end plate openings <NUM> aligned with a pair of extensions <NUM> that are both sized to receive the pair of spring rods <NUM> therein. The end plate <NUM> includes an actuator opening <NUM> sized to receive the linear actuator <NUM>. The end plate <NUM> includes one or more pin holes <NUM> along each of wing portions <NUM>. Each of the one or more pin holes <NUM> is configured to align with corresponding holes <NUM> in a shank plate <NUM>. The end plate <NUM> is attached to the shank plate <NUM> via a pair of pins <NUM> that are received in the pin holes <NUM> and holes <NUM> wherein the end plate <NUM> can be adjusted relative to the shank plate <NUM> by aligning the pin holes <NUM> to holes <NUM>. Adjustment of the end plate <NUM> relative to the shank plate <NUM> can change the distance the pair of springs <NUM> can travel to thereby increase or decrease the spring stiffness and the corresponding downforce on the pair of closing wheels <NUM>. As can be appreciated, the pair of pins <NUM> enable adjustment of the end plate <NUM> along the length of the pair of spring rods <NUM> to thereby compress the pair of springs <NUM> to increase or decrease the stiffness of the pair of springs <NUM> and correspondingly increase or decrease the downforce on the pair of closing wheels <NUM>. For example, if the end plate <NUM> is moved closer to the spring housing <NUM>, then the stiffness of the pair of springs <NUM> increases as the end plate <NUM> engages the pair of springs <NUM>. Alternatively, if the end plate <NUM> is moved further away from the spring housing <NUM>, then the stiffness of the pair of springs <NUM> decreases as the end plate <NUM> moves away from the pair of springs <NUM>. The effective location of the pair of pins <NUM> and end plate <NUM> is moved away from the end of the linear actuator <NUM> which is beneficial for the pair of springs <NUM> as this arrangement increases the amount of space for which the springs <NUM> can travel. This arrangement is beneficial to decrease the length of actuator needed by moving the end plate <NUM> away from the end of the linear actuator <NUM> which effectively moves the end of linear actuator <NUM> out because the end plate <NUM> is moved out.

The shank plate <NUM> is mounted on the shank extension <NUM>, however in other embodiments the shank plate <NUM> is monolithic with the shank extension <NUM>. The shank plate <NUM> includes a pair of wings <NUM> that include the holes <NUM> therein.

Alternatively, or in addition to moving the end plate <NUM> relative to the pair of spring rods <NUM>, the linear actuator <NUM> is operable to move a desired stroke length to provide an actuator force to the pair of springs <NUM> to compress or increase the stiffness of the pair of springs <NUM>. The amount of actuator force that is applied by the linear actuator <NUM> to the pair of springs <NUM> varies as desired, and in one embodiment the amount of actuator force is between <NUM> and <NUM> Newtons. The linear actuator <NUM> applies the actuator force to the pair of springs <NUM> to increase the stiffness by compressing the pair of springs <NUM> which corresponds to an increase in the downforce applied to the pair of closing wheels <NUM>. The increase in the downforce applied to the pair of closing wheels <NUM> assists to overcome shock loading issues when the row unit <NUM> traverses an obstacle such that the pair of closing wheels <NUM> maintain contact with the ground surface while the row unit <NUM> traverses the obstacle. In one embodiment, the downforce of the pair of closing wheels <NUM> is between <NUM> and <NUM> Newtons.

The linear actuator <NUM> moves per its stroke length to compress the pair of springs <NUM> to change the spring force of the pair of springs <NUM> but the linear actuator <NUM> does not directly change the position of the pair of closing wheels <NUM>. The linear actuator <NUM> changes the spring stiffness of the pair of springs <NUM> to change the downforce output of the pair of closing wheels <NUM>. The pair of springs <NUM> can have a progressive spring rate or a constant spring rate, and each of the pair of springs <NUM> can include multiple springs wherein each of the multiple springs can have the same or different spring rate. Two extreme loading situations will be described with respect to <FIG> and <FIG>. In one embodiment illustrated in <FIG>, the pair of closing wheels <NUM> will free fall from horizontal reference line "R" into a pit, hole "H", or other concave surface when the row unit <NUM> travels over the pit, however the actuator <NUM> has a <NUM> millimeter stroke length which results in no change in the spring stiffness of the pair of springs <NUM> therefore the pair of closing wheels <NUM> apply a minimum amount of downforce to the ground surface. The closing wheels <NUM> float and maintain contact with the concave surface in <FIG> which illustrate the lowermost position. As another example, illustrated in <FIG>, the pair of closing wheels <NUM> hit an obstacle as measured relative to a horizontal reference line "R" as the row unit <NUM> travels over the obstacle "O", however the actuator <NUM> has a maximum stroke length which results in a maximum increase in the spring stiffness of the pair of springs <NUM> such that the pair of closing wheels <NUM> apply a maximum amount of downforce to the ground surface however the pair of springs <NUM> account for sudden impact caused by the closing wheels <NUM> striking the obstacle. The closing wheels <NUM> float and maintain contact with the obstacle in <FIG> which illustrate the uppermost position. As can be appreciated, the maximum down force of the closing wheels <NUM> occurs when the linear actuator <NUM> is at the end of its stroke length and the minimum down force of the closing wheels <NUM> occurs when the linear actuator <NUM> has <NUM> stroke length such that the linear actuator <NUM> has not increased the spring stiffness of the pair of springs <NUM>. The spring stiffness of the pair of springs <NUM> is not increased to the maximum amount therefore the pair of springs <NUM> are able to withstand shock loading as the closing wheels <NUM> encounter obstacles, ground undulations, rocks, pits, holes, or concave surfaces.

In the illustrated embodiment, the linear actuator <NUM> is an electronic self-locking actuator that can adjust and maintain a certain amount of compression of the pair of springs <NUM> yet allows for travel of the pair of closing wheels <NUM> to follow the ground undulations. If the self-locking feature is engaged for the linear actuator <NUM> such that the linear actuator <NUM> is in a locked position with an extended stroke, no additional electrical power is needed to maintain the stroke length of the locked linear actuator <NUM>. The downforce on the closing wheels <NUM> increases as a result of an increase in the spring stiffness of the pair of springs <NUM> from the actuator force of the linear actuator <NUM>. If the linear actuator <NUM> is moved to a desired position to increase the spring stiffness of the pair of springs <NUM>, the closing system <NUM> is still able to overcome shock loading as the pair of springs <NUM> absorb the shock force or load. The shock force is absorbed by the mechanical elements or pair of springs <NUM> so that the stroke position of the actuation device or linear actuator <NUM> remains unchanged during the shock event and is able to return to nominal force condition after the shock event.

The linear actuator <NUM> in a locked position maintains an increased spring stiffness of the pair of springs <NUM> that correspondingly increases the downforce of the pair of closing wheels <NUM> to thereby adjust and react to soil and ground undulations without applying additional electric power to the linear actuator <NUM>. As such, the self-locking linear actuator <NUM> only uses electric power when actuating and electric power is not applied to the motor of the linear actuator <NUM> all the time, which would be a waste of power. The position of the linear actuator <NUM> can be changed with electric power to thereby change a nominal force setting of the pair of closing wheels <NUM> while providing the ability of the closing wheels <NUM> to float and follow ground undulations or breakaway upon rock strike. In other words, the nominal force setting of the pair of closing wheels <NUM> can change with electric power being applied only to the linear actuator <NUM>.

Although the spring stiffness of the pair of springs <NUM> may be increased when the linear actuator <NUM> is engaged to increase its stroke length, the full actuator load force on the pair of springs <NUM> is typically not applied as the full amount of the actuator load force is often not needed. The benefit of a self-locking linear actuator <NUM> to hold the stroke length of the linear actuator <NUM> relative to the end plate <NUM> and thereby compress the pair of springs <NUM> coupled with the ability of the pair of closing wheels <NUM> to change position with or float along the ground undulations by rotating about pivot <NUM> provides mechanical shock absorbing by the pair of springs <NUM>.

In other embodiments, the linear actuator <NUM> is replaced with a mechanical device such as a hydraulic cylinder, an accumulator, and/or a spring in which none of these mechanisms require electrical power. Other forms of actuators include electrohydraulic actuator, ball or screw drive, radial spring, or a leaf spring, to name a few. In these alternative embodiments, the devices may lock to hold a certain position relative to the pair of springs <NUM> to thereby adjust the spring stiffness of the pair of springs <NUM> and the corresponding downforce of the pair of closing wheels <NUM> that float on the ground surface.

As can be appreciated with the side by side arrangement of the linear actuator <NUM> and the pair of springs <NUM>, there are advantages to a control aspect, cable routing, efficiency with electronically activated system to change the downforce of the pair of closing wheels <NUM>. The closing wheel system <NUM> changes the downforce of the closing wheels <NUM> and the closing wheel system <NUM> is robust to changing ground conditions. The linear actuator <NUM> is fixed, and without the pair of springs <NUM>, does not have any give or flexibility such that if the closing wheels <NUM> hit an immovable object, the linear actuator <NUM> can potentially break because the linear actuator <NUM> cannot withstand the shock loading. However, the linear actuator <NUM> coupled with the pair of springs <NUM> overcomes or absorbs the shock load but does not directly change the position of the closing wheels <NUM>. The linear actuator <NUM> changes the spring force or K in the pair of springs <NUM>.

The closing wheel system <NUM> can be connected to controllers and computerized systems to perform user entered, remote, or automatic adjustments. The automation of the closing wheel system <NUM> with attachment to a controller and one or more sensors can control speed, routing, adjust faster, and closed loop control (A2A) using force/stroke feedback from the linear actuator <NUM> which can be embedded in the linear actuator <NUM>. The closed loop aspect can be based on feedback such as a camera processing images that show voids in soil or no voids in soil and adjust the downforce of the closing wheels <NUM> accordingly. Operator input can adjust the downforce to be applied by the closing wheels <NUM> by adjusting the linear actuator <NUM>, alternatively in other embodiments there is an automatic adjustment of the downforce such as by utilizing ground sensing techniques. In other embodiments, the downforce can be adjusted via a prescription that enables adjustment according to certain boundaries of a field or time of year.

A second embodiment of a closing wheel system <NUM> is illustrated in <FIG>, <FIG>, and <FIG>. All of the elements of the closing wheel system <NUM> are the same as the closing wheel system <NUM>, however endplate <NUM> has a slightly different shape than endplate <NUM>. Endplate <NUM> functions substantially the same way as endplate <NUM>.

It should be appreciated that the disclosure herein is applicable to agricultural machines including drawn planters, integral planters, and any other row crop planters having row units, and is also applicable to clearing discs, tillage tines, fertilizer openers, and other systems that can benefit from a similar side-by-side arrangement of an electrically operated self-locking system, such as an actuator, to engage a mechanical system to increase a downforce output. Although illustrated in a side-by-side arrangement, it is understood that the same arrangement can be used vertically.

While this disclosure has been described with respect to at least one embodiment, the present disclosure can be further modified within the scope of this disclosure.

Claim 1:
A closing system (<NUM>) for a row unit (<NUM>) of a work machine, the closing system (<NUM>) comprising:
one or more closing wheels (<NUM>) that are operable to contact a ground surface,
a first actuator (<NUM>) and a second actuator,
the first actuator (<NUM>) operable to engage the second actuator,
the second actuator configured to engage the one or more closing wheels (<NUM>) and to absorb a shock force,
the first actuator (<NUM>) is operable to engage the second actuator to increase an amount of force that the second actuator applies to the one or more closing wheels (<NUM>), wherein
the second actuator includes one or more springs (<NUM>) that are operable to apply an initial amount of force to the one or more closing wheels (<NUM>) and wherein
the first actuator (<NUM>) is operable to apply an actuator force to the one or more springs (<NUM>) to increase the amount of force that the one or more springs (<NUM>) apply to the one or more closing wheels (<NUM>), and wherein
a shank (<NUM>) of the row unit (<NUM>) pivotally coupled at a pivot (<NUM>) to a shank extension (<NUM>) and
the one or more closing wheels (<NUM>) are rotatably mounted on the shank extension (<NUM>),
characterized in that
the first actuator (<NUM>) is arranged parallel to the second actuator.