Precision hoe opener with swing link and biasing member

A precision hoe opener assembly is provided with improved accuracy of seeding as well as improved control over the opener and packer wheel assemblies. The opener assembly includes a hydraulically-driven parallel linkage assembly, a lost motion linkage, a biasing member, a ground engaging tool, and a packer wheel. The design provides improved seeding accuracy, by compensating for changes in draft force caused by changes in terrain elevation.

BACKGROUND

The invention relates to agricultural seeders, such as hoe openers and seeding tools used in farming operations to distribute seeds into the soil.

Generally, precision hoe openers are mounted to the frame of an implement which is towed behind a tractor. These openers may include a ground engaging tool or ground opener that opens the soil, providing a seeding path for seed deposition into the soil. The ground opener is used to break the soil to enable seed deposition. After the seed is deposited, the ground engaging tool may be followed by a packer wheel that packs the soil on top of the deposited seed. The packer wheel may be rigidly mounted behind the ground engaging tool via a structural member or rear frame. Thus, the ground engaging tool and packer wheel generally move together with the same upward and downward motion. This vertical motion, somewhat independent of the implement frame, allows for more precise placement of seed in the soil.

Unfortunately, existing precision hoe openers do not adequately address the need for height variation over terrain during seeding, or for transportation when not seeding. It is generally undesirable to pull the hoe opener through soil when merely transporting the opener from one location to another. In addition, during seeding, existing openers do not provide adequate vertical motion of the opener and related assembly without compromising the load on the ground engaging tool and packer wheel. As a result, variations in the terrain can result in drastic changes in the packing force (e.g., normal force) of the packer wheel on the terrain being seeded by the opener and, also, the draft force of the terrain on the ground engaging tool. In turn, this variation in packing and ground opening force can result in non-uniform seeding depths and packing density in the terrain being seeded by the system.

The distance between the packer wheel and ground engaging tool can also affect the seeding accuracy of the opener assembly. Existing precision hoe openers have a fixed distance between the packer wheel and opener. A greater distance between the components will cause variations in the terrain to greater affect the force on the ground engaging tool or packer wheel. This will also result in non-uniform force applied to the soil by the two components, which reduces seeding accuracy. For instance, some existing precision hoe openers may employ a parallel linkage to control the location of the packer wheel and opener. One of the difficulties in using a parallel linkage is that the force at the packer wheel will fluctuate as the draft force applied to the opener displaces the linkage.

Existing precision hoe openers also require substantial force to raise the opener assembly, including the ground engaging assembly and packer wheel. This requirement results in the use of large hydraulic cylinders to raise the apparatus, due to the overall length and weight of each opener assembly. This hydraulic equipment is costly and takes resources (i.e. hydraulic power) from other portions of the tractor and seeding implement.

There is a need, therefore, for improved arrangements in precision hoe openers and seeder systems that improve the accuracy of the seeding operation. There is a particular need for a precision hoe opener configuration that applies forces to the ground engaging tool and the packing wheel to improve seeding accuracy while also increasing the mobility of the opener.

BRIEF DESCRIPTION

It should be understood that the following discussion, and specific embodiments, are presented merely to provide the reader with a brief summary of certain forms the invention might take and that these embodiments are not intended to limit the scope of the invention. Indeed, the invention may encompass a variety of aspects that may not be set forth below.

Embodiments of the present invention address the problem of inadequate vertical motion of the tool by optimizing the geometric relationship of the cylinder, parallel linkage, ground engaging tool, and packer wheel. Specifically, embodiments of the present invention allow for additional motion between the shank and cylinder by incorporating a swing link assembly between these elements. The swing link enables the cylinder to travel farther than if it were rigidly mounted to the shank providing for alternative positions as the cylinder is extended or retracted. These alternative positions allow for both additional vertical motion of the assembly and the desired loading on the opener and packer wheel.

Further, the shank and ground engaging tool may be loaded by a biasing member, such as a spring, coupled to the swing link assembly, thereby enabling retraction of the shank prior to the retraction of the remaining assembly. This enables an operator to independently retract the ground engaging tool without having to retract the entire assembly. This may be beneficial when the operator has reached the end of a row and must turn to position the tractor and precision hoe opener for the next seeding pass.

Embodiments of the present invention include draft compensation in the parallel linkage to counteract draft forces placed on the ground engaging tool during operation. Embodiments of the present invention are configured to enable the hydraulic load of the cylinder to compensate and counteract the varying draft loads on the ground engaging tool, thereby maintaining a substantially constant packing pressure on the packer wheel.

DETAILED DESCRIPTION

Turning now to the drawings and referring first toFIG. 1, an embodiment of a precision hoe opener assembly is illustrated and designated generally by reference numeral10. Precision opener assembly10includes a frame support12, a linear actuator such as a cylinder14(e.g. a hydraulic, piston-driven assembly), a swing link assembly16, a packer wheel assembly18(e.g., a packer arm), and a packer wheel20. Precision hoe opener assembly10may be towed, pushed, or generally moved by a vehicle, such as a tractor (not shown). For example, the frame support12may be connected to tool frame tow bar22attached to the tractor for towing the precision hoe opener assembly10. The precision opener assembly10is mounted to the tractor support via mounting brackets24. In the present context, the precision hoe opener assembly10may also be generally referred to as an opener assembly, a hoe opener, a row unit, a seeder, a planter, an opener or a ground engaging tool/assembly. Further, the ground engaging tool or opener is the portion of the hoe opener assembly that contacts the ground, thereby preparing the soil for seed deposition.

Tool frame support12is connected to the swing assembly16of packer wheel assembly18via the cylinder14, first member26, and second member28. The mounting configuration of cylinder14, first member26, and second member28will be discussed further below. Cylinder14is mounted to swing link assembly16via pin30. Cylinder14is hydraulically coupled to a power supply32that may be used to pressurize piston rod34to actuate the swing link assembly16. Once actuated, swing link assembly16may engage packer wheel assembly18via a stop as will be described further below. The swing link assembly16engages the packer wheel assembly18via a shank mount adapter36. The shank mount adapter36is coupled to a shank38and a first ground engaging tool40. Shank mount adapter36may be coupled to shank38via fasteners42, which allow height adjustments for ground engaging tool40. Packer wheel assembly position adjustments can be made via adjuster44. First ground engaging tool40is coupled to a seed distribution header46via a seeding tube48to allow product deposition during operation. The present embodiment illustrates an optional second ground engaging tool50, which may be added in some cases to allow for a second product to be placed in the ground. The adjustments enabled by fasteners42and adjuster44may optimize product placement accuracy by allowing packer wheel20to move vertically with respect to first opener40and second opener50. Moreover, the optional second ground engaging tool may affect the packing forces and/or compensation of the system, but likely not significantly alter the basic design of the precision hoe opener assembly and swing link mechanism.

First member26is attached via pins54, and56to tool frame support12, rear frame58, and packer wheel assembly18. Second member28is connected to rear frame58and tool frame support12via pins60and52. Further, pins60and54couple rear frame58to the packer wheel assembly18and shank mount adapter36as well as second member28. The elements12,26,28, and58may be collectively described as a four-bar linkage or parallel linkage assembly. As depicted, the parallel linkage assembly is driven by cylinder14.

As discussed above, cylinder14actuates swing link assembly16to load shank38, which further loads packer wheel assembly18and packer wheel20. In certain embodiments, the packer wheel20provides a substantially constant force to the soil after the seed has been deposited. As is known in the art, packer wheel20is coupled to packer wheel assembly18via a rotating bearing. Further, packer wheel assembly18includes multiple mounting locations on adjuster44to allow for adjustment of the packer wheel20. As stated above, seeding accuracy may be enhanced by adjusting the position of packer wheel20.

In the present embodiment, shank mount adapter36and swing link assembly16are coupled by a biasing spring member62. As will be appreciated by those skilled in the art, the biasing member may take many forms, such as a spring, an elastic band or any other suitable device. Biasing spring member62allows swing link assembly16to provide a raising force to shank mount adapter throughout the angular range of swing link assembly16.

FIG. 2illustrates a portion of the precision hoe opener10with certain features removed for clarity, such as packer wheel20, packer wheel assembly18, and first member26. The figure illustrates the tool frame support12, cylinder14, second member28, swing link assembly16, and shank mount adapter36. Precision hoe opener10is shown with the swing link assembly16and first ground engaging tool40in a retracted position away from (and above) the ground. The cylinder14is retracted, thereby stretching biasing spring member62in tension. Further,FIG. 3is a perspective view of the shank mount adapter36, swing link assembly16, and their related elements.

Referring to bothFIGS. 2 and 3, shank mount adapter36includes a main body having a number of features. These features interface the swing link assembly16during either retraction or extension of the cylinder14. The swing link assembly includes extension mating feature64that interfaces with extension contact surface66. These features provide greater leverage about pin60for cylinder14, reducing the amount of hydraulic power needed to move the opener assembly. The swing link assembly16may be described as contacting the surfaces of shank mount adapter36at the extremities of the angular rotational movement of the swing link assembly16in order to raise or lower the shank. Further, when in the extension position, as shown inFIG. 3, frame stop cavity68rotates as well, engaging a frame stop, located on the rear frame, to provide a lowering force upon the packer wheel assembly. It follows, that when the swing link assembly16is in a retraction position, as shown inFIG. 2, the frame stop may provide a lifting force to the packer wheel assembly.

As swing link assembly16retracts, shown inFIG. 2, biasing spring member62is stretched while providing a lifting force to shank mount adapter36. Biasing spring member62is attached to members70and72, which are rigidly coupled to swing link assembly16and shank mount adapter36, respectively. As will be appreciated by one skilled in the art, a portion of the angular movement of the swing link assembly16will not cause movement of the packer wheel assembly. This is due to the “stretching” of spring member62that is necessary to initiate a lifting force. This characteristic may cause the swing link assembly16to be referred to a lost motion linkage.

FIG. 3shows the swing link assembly16in the extension position to engage the shank mount adapter36to extend the first ground engaging tool40and packer wheel assembly18. In this position, extension mating feature64engages extension contact surface66. Also shown are retraction mating feature74and retraction contact surface76. In the present embodiment, the geometry of swing link assembly16reduces the required lengths for members26and28necessary to raise and lower opener assembly10. In order to move the opener assembly10, cylinder14is attached to the swing link assembly16via cylinder adapter78.

Referring back toFIG. 2, the swing link assembly16is shown in the retracted position in which the first ground engaging tool40is lifted higher than the packer wheel20. In the illustrated retracted position, retraction mating feature74engages retraction contact surface66. As shown inFIGS. 2 and 3, the cylinder14and piston rod34are not directly coupled to shank mount adapter36. Instead, the first ground engaging tool40is retracted and extended via the swing link assembly16engaging and disengaging the shank mount adapter36.

Further, biasing spring member62enables retraction of shank mount adapter36via connection members70and72. This configuration may enable optimization of the geometry for the seeding operation by enabling an operator to retract the shank mount adapter36without further raising the packer wheel assembly18. For example, when an operator approaches the end of a row, that operator may retract only the first ground engaging tool40in order to make a turn to seed the next row. In other words, the operator does not have to retract the entire precision hoe assembly10and packer wheel20because the biasing spring member62raises shank mount adapter36before retraction mating feature74and surface76are engaged.

FIG. 4illustrates an embodiment of the precision hoe opener10in a deployed position as might be representative of being towed during a seeding operation. In this deployed position, shank mount adapter36rotates about pin60, along with frame stop cavity68, to lower first ground engaging tool40and engage the frame stop located on rear frame58. When shank mount adapter36rotates about pin60and engages frame stop cavity68, shank mount adapter36loads packer wheel assembly18which is coupled to rear frame58. The resulting force applies a load to packer wheel20via the parallel linkage assembly.

In general, the figures illustrate that the precision opener assembly10has an increased range of motion providing a generally constant packing force to the soil. This is achieved by the opener assembly10maintaining a substantially constant angle between packer wheel assembly18and terrain in combination with the geometry of cylinder14, first member26, and second member28.

The disclosed embodiments of the precision hoe opener assembly10provide precision control of the packing force by the packer wheel20and the seeding depth by the first ground engaging tool40. The opener assembly10advantageously responds to variations in the terrain, the draft force on the first ground engaging tool40, the packing force, or a combination thereof. Thus, the opener assembly10can provide a generally uniform packing force and seeding depth to improve the overall quality of the seeding process, and in turn improve subsequent growth originating from the seeds. Again, the hoe opener assembly10has a variety of adjustment mechanisms to control the location of the packer wheel20, the first ground engaging tool40, the optional second ground engaging tool50, or a combination thereof.

Finally,FIG. 5illustrated the precision hoe opener assemblies10as row units of a complete agricultural seeder system80, as towed behind a tractor. As shown in the diagram, the seeder system80includes a plurality of opener assembly row units mounted on several tool frame bars which are generally transverse to the direction the seeder system is pulled. As the seeder system80is towed across a field with the row units deployed, a plurality of rows of crops may be seeded in each pass.