Abstract:
An agricultural implement is provided that includes a first tool bar supporting first ground engaging tools. The agricultural implement further includes a second tool bar supporting second ground engaging tools and coupled to the first tool bar by a pivot joint. Additionally, the agricultural implement includes a working plate secured to the first tool bar and having a joint structure partially defining the pivot joint. Furthermore, the agricultural implement includes a stress feathering plate secured between the working plate and the first tool bar and secured to both the working plate and the first tool bar, the stress feathering plate extending beyond the working plate and having a contour that provides a reduced stress gradient when the first tool bar, the working plate and the stress feathering plate are loaded by engagement of the first and second ground engaging tools with the ground.

Description:
BACKGROUND 
     The invention relates generally to ground working equipment, such as agricultural equipment, and more specifically, to an implement having reinforcing members that reduce stress concentrations encountered when forces are applied by engagement of the ground. 
     Generally, fertilizer application implements are towed behind a tractor or other work vehicle via a hitch assembly secured to a rigid frame of the implement. These fertilizer application implements typically include one or more ground engaging tools or openers that form a path for fertilizer deposition into the soil. The openers are used to break the soil, thereby enabling injection nozzles (e.g., positioned behind the openers) to deposit fertilizer at a desired depth beneath the soil surface. In certain embodiments, the implement may include knives (e.g., positioned behind the openers), instead of the injection nozzles, to flow the liquid fertilizer into respective trenches formed by the openers and knives. Using such implements, fertilizer may be distributed throughout a field, either before or after planting, to facilitate enhanced crop development. 
     BRIEF DESCRIPTION 
     In one embodiment, a towed implement includes a first tool bar supporting first ground engaging tools. The agricultural implement also includes a second tool bar supporting second ground engaging tools and coupled to the first tool bar by a pivot joint. Additionally, a working plate secured to the first tool bar and having a joint structure partially defining the pivot joint. Furthermore, a stress feathering plate secured between the working plate and the first tool bar and secured to both the working plate and the first tool bar. The stress feathering plate extends beyond the working plate and has a contour that provides a reduced stress gradient when the first tool bar, the working plate and the stress feathering plate are loaded at least in part by engagement of the first and second ground engaging tools with the ground. 
     In another embodiment, a towed implement includes a first tool bar supporting first ground engaging tools. The towed implement further includes a second tool bar supporting second ground engaging tools and coupled to the first tool bar by a pivot joint. Additionally, the agricultural implement includes a fore structure disposed on a fore side of the first tool bar, the fore structure having a fore working plate secured to the fore side of the first tool bar and having a joint structure partially defining the pivot joint, and a fore stress feathering plate secured between the fore working plate and the fore side of the first tool bar and secured to both the fore working plate and the fore side of the first tool bar, the fore stress feathering plate extending beyond the fore working plate and having a contour that provides a reduced stress gradient when the first tool bar, the fore working plate and the fore stress feathering plate are loaded at least in part by engagement of the first and second ground engaging tools with the ground. Furthermore, the agricultural implement includes an aft structure disposed on an aft side of the first tool bar, the aft structure includes an aft working plate secured to the aft side of the first tool bar and having a joint structure partially defining the pivot joint, and an aft stress feathering plate secured between the aft working plate and the aft side of the first tool bar and secured to both the aft working plate and the aft side of the first tool bar, the aft stress feathering plate extending beyond the aft working plate and having a contour that provides a reduced stress gradient when the first tool bar, the aft working plate and the aft stress feathering plate are loaded at least in part by engagement of the first and second ground engaging tools with the ground. 
     In a further embodiment, a towed implement includes a first tool bar supporting first ground engaging tools. The agricultural implement also includes a second tool bar supporting second ground engaging tools and coupled to the first tool bar by a pivot joint. Additionally, the agricultural implement includes a first structure disposed on the first tool bar, the first structure includes a first working plate secured to the first tool bar and having a joint structure partially defining the pivot joint, and a first stress feathering plate secured between the first working plate and the first tool bar and secured to both the first working plate and the first tool bar, the first stress feathering plate extending beyond the first working plate and having a contour that provides a reduced stress gradient when the first tool bar, the first working plate and the first stress feathering plate are loaded at least in part by engagement of the first and second ground engaging tools with the ground. Furthermore, the agricultural implement includes a second structure disposed on the second tool bar, the second structure includes a second working plate secured to the second tool bar and having a joint structure partially defining the pivot joint, and a second stress feathering plate secured between the second working plate and, the second tool bar and secured to both the second working plate and the second tool bar, the second stress feathering plate extending beyond the second working plate and having a contour that provides a reduced stress gradient when the second tool bar, the second working plate and the second stress feathering plate are loaded by engagement of the first and second ground engaging tools with the ground. 
    
    
     
       DRAWINGS 
       These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein: 
         FIG. 1  is a perspective view of an embodiment of an agricultural implement having a storage tank mounted between frame rails, foldable wings and mechanical reinforcing members designed to reduce stresses; 
         FIG. 2  is a perspective view of an embodiment of an agricultural implement illustrating pivot joints; 
         FIG. 3  is a front perspective view of an embodiment of a right pivot joint of  FIG. 2  illustrating components designed to provide reduced stress gradients; 
         FIG. 4  is a front perspective view of an embodiment of a right pivot joint of  FIG. 2  with a front right feathering plate that reduces stress gradients; 
         FIG. 5  is a front perspective view of an embodiment of a left pivot joint of  FIG. 2  illustrating components designed to provide reduced a stress gradients; and 
         FIG. 6  is a front perspective view of an embodiment of a left pivot joint of  FIG. 2  with a front right feathering plate that reduces stress gradients. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a perspective view of an embodiment of an agricultural implement  10  having a storage tank mounted between frame rails. In the illustrated embodiment, the implement  10  is configured to be towed along a direction of travel  12  by a work vehicle, such as a tractor or other prime mover. The work vehicle may be coupled to the implement  10  by a hitch assembly  14 , such as the illustrated “goose neck” pull frame. As illustrated, the hitch assembly  14  is coupled to a main frame  16  of the implement  10  to facilitate towing of the implement  10  in the direction of travel  12 . In the illustrated embodiment, the main frame  16  supports a storage tank  18  configured to house a flowable agricultural product, such as liquid fertilizer. A pair of wheels  20  coupled to the main frame  16  is configured to support the weight of the frame  16 , the storage tank  18 , and the flowable agricultural product, thereby enabling the implement  10  to be towed across the field. 
     The implement  10  is configured to transfer the flowable agricultural product from the storage tank  18  to multiple row units  22  of a tool bar assembly  24 . Each row unit  22  includes a ground engaging tool configured to break the soil, thereby excavating a trench into the soil. An injection nozzle or knife (e.g., positioned behind the ground engaging tool) is configured to deposit flowable agricultural product from the storage tank  18  into the trench formed by the ground engaging tool. In certain embodiments, the penetration depth of the ground engaging tools is adjustable to facilitate deposition of the agricultural product at a desired depth beneath the soil surface. Accordingly, a flowable agricultural product, such as liquid fertilizer, may be distributed throughout a field, either before or after planting, to facilitate enhanced crop development. 
     While the illustrated implement  10  includes 25 row units  22 , it should be appreciated that alternative implements may include more or fewer row units  22 . For example, certain implements  10  include a tool bar assembly  24  having a right outer wing  26 , a right inner wing  28 , a central tool bar  30 , a left inner wing  32 , and a left outer wing  34 . Additionally, certain implements may include the row units  22  distributed across the central tool bar  30  and wings  26 ,  28 ,  32 , and  34 . As discussed below in further detail, the number of row units and the spacing between row units may be particularly selected to correspond to the arrangement of row units on respective seeding or planting implements. For example, the implement  10  may include 25 row units  22  spaced 30 inches from one another. Accordingly, as the implement  10  is towed across a field, the row units  22  deposit fertilizer in rows having 30-inch spacing. After the fertilizer is applied, a seeding or planting implement (e.g., having row units spaced 30 inches from one another) may deposit seeds between the rows of fertilizer (e.g., the approximate midpoint between rows), thereby facilitating enhanced crop development. In addition, the implement  10  may be utilized to apply fertilizer to previously planted seeds (e.g., via injecting fertilizer between rows of the previously planted seeds). 
     As discussed in further detail below, the agricultural implement  10  has foldable wings (e.g., right outer wing  26 ) each having one or more row units  22  attached. Additionally, the foldable wings may fold to allow the agricultural implement  10  to change the number of row units  22  that engage the ground during operation of the agricultural implement  10  on a field. By enabling the agricultural implement  10  to change the number of row units  22  engaging the field, the agricultural implement  10  may be efficiently operated in fields planted with row planters with various numbers of rows planted. For example, in certain embodiments, the agricultural implement  10  may be used in a field that has been planted with a planter having 16 rows when one or more wings are placed in a folded position, but the agricultural implement  10  may be suitably used in a field that has been planted with a planter having 24 rows when the wings are deployed in the unfolded position. In other embodiments, the agricultural implement  10  may engage 25 or more row units  22  with the ground when all wings are deployed in the unfolded position, but may engage less row units  22  with the ground when one or more wings are deployed in the folded position. 
     By enabling the agricultural implement to operation with variable widths, one model of the agricultural implement  10  may be used on to fertilize a variety of fields. Furthermore, by making one agricultural implement  10  capable of operating in various field types, a versatile embodiment of the agricultural implement  10  enables many users (e.g., an agricultural cooperative program) to purchase one agricultural implement  10  that may be shared between multiple field types within the group even if the fields have various sizes and/or are planted with various planter sizes/types. 
       FIG. 2  is a perspective view of the agricultural implement  10  illustrating pivot joints between each respective wing and another wing/central tool bar  30  that each allow a respective wing to rotate in relation to a connected wing/central tool bar  30 . Specifically, a right outer pivot joint  36  couples the right outer wing  26  to the right inner wing  28 , and a right pivot joint  38  couples the right inner wing  28  to the central tool bar  30 . Similarly, a left outer pivot joint  40  couples the left outer wing  34  to the left inner wing  32 , and a left pivot joint  42  couples the left inner wing  32  to the central tool bar  30 . 
     Additionally, the agricultural implement  10  includes mechanical devices that fold one or more wings. For example, a right outer actuating cylinder  44  may urge the right outer wing  26  into the illustrated unfolded position or may urge the right outer wing  26  into a folded position above the right inner wing  28 . As can be appreciated, to fold the right outer wing  26  into a folded position above the right inner wing  28 , the right outer actuating cylinder  44  may be retracted to urge the right outer arms  46  toward the right inner wing  28  and to urge the right outer wing  26  to fold inwardly toward the right inner wing  28 . Similarly, the right outer wing  26  may be rotated to the illustrated unfolded position from a folded position by extending the right outer actuating cylinder  44  thereby urging the right outer wing  26  back to the illustrated unfolded position. Similar to the right outer wing  26 , the right inner wing  28  may folded/unfolded by retracting/extending the right actuating cylinder  48  thereby urging the right arms  50  in a corresponding direction. Finally, the left inner wing  32  may folded/unfolded by retracting/extending the left actuating cylinder  52  thereby urging the left arms  54  in a corresponding direction, and the left outer wing  34  may be folded/unfolded by retracting/extending the left outer actuating cylinder  56  thereby urging the left outer arms  58  in a corresponding direction. Additionally, as can be appreciated, the central tool bar  30  and the wings  26 ,  28 ,  32 , and  34  are subject to drag when the row units  22  engage the ground during operation of the agricultural implement  10 . Although it is desirable that each of the wings  26 ,  28 ,  32 , and  34  withstand expected drag during operation, it is also desirable to reduce the weight of the wings  26 ,  28 ,  32 , and  34  to reduce the power needed to fold/unfold the wings as well as reduce the stress that results from the folding/unfolding. In other words, each of the wings  26 ,  28 ,  32 , and  34  are designed to withstand drag while minimizing total weight. 
       FIG. 3  is a front perspective view of an embodiment of the right pivot joint  38  illustrating components for reducing stress gradients when the implement is towed through and contacts the ground in a field. The stresses may be illustrated as having stress areas  60  under various levels of force resulting from drag occurring when the row units  22  engage the ground. The right pivot joint  38  includes a front right working plate  62  that is coupled to central tool bar  30  by a bolt  64  and welded to the right inner wing  28  along a weld edge  66 . As the distance from the bolt  64  increases, the stress exerted in each stress area  60  are reduced. In certain embodiments, the front right working plate  62  may have a thickness of 1, 1.25, or 1.5 inches, although other thicknesses maybe appropriate. Additionally, some embodiments include a front right working plate  62  having a weld edge  66  that is generally flat and/or substantially vertical. This bolt and weld connection enable the right inner wing  28  to pivot relative to the central tool bar  30 . As can be appreciated, when the row units  22  coupled to the agricultural implement  10  engage the ground, the right inner wing  28  and the central tool bar  30  are subject to drag opposing the direction of travel  12 . Furthermore, the stress on the right inner wing  28  and the central tool bar  30  increases around the right pivot joint  38  due to the discontinuity (e.g., break and/or change in size) between the right inner wing  28  and the central tool bar  30 . Accordingly, the weld edge may traverse one or more areas of high stress on the right inner wing  28  thereby increasing stress on the weld connections and/or right inner wing  28  (i.e., the base metal or member). 
       FIG. 4  is a front perspective view of an embodiment of the right pivot joint  38  with a front right feathering plate  68  designed to reduce stress gradients by extending support and resistance to stresses further out, and in a desired geometry. Thus, the front right feathering plate  68  includes a contour  70 . In certain embodiments, the front right feathering plate  68  includes a contour  70  with an elongated shape, a C-shape, or other suitable shapes. In certain embodiments, the front right feathering plate  68  includes a thickness less than the thickness of the front right working plate  62 . For examples, some embodiments may include a front right feathering plate  68  that has a thickness of 1, 0.75, 0.5, 0.375, or less inches. Additionally, the front right feathering plate  68  is welded to the right inner wing  28  at or around the contoured tip  72 . Accordingly, the weld connection to the right inner wing  28  is moved further from the bolt  64  to reduce the stress on the weld. As can be appreciated, by moving the weld point on the right inner wing  28  away from the bolt  64  to the contoured tip  72  using the front right feathering plate  68 , the stress on the weld connection is reduced when compared to the weld connections in  FIG. 3 . 
     Additionally, the front right feathering plate  68  is welded to the front right working plate  62  at the weld edge  66  and/or other edges. In certain embodiments, the front right working plate  62  and the front right feathering plate  68  may be welded before or after welding connections between the front right feathering plate  68  and the right inner wing  28  are joined. In other embodiments, the front right feathering plate  68  and the front right working plate  62  may be physically stacked and concurrently welded to each other and the right inner wing  28 . Furthermore, by distributing drag throughout the right inner wing  28  using the front right feathering plate  68 , the stress exerted on the weld edge  66  is reduced thereby reducing the likelihood of failure of the right pivot joint  38 . 
     The right pivot joint  38  may also include a rear right feathering plate (not pictured) that welds to a rear right working plate and the left inner wing  28 . In certain embodiments, the rear right feathering plate may include a contour having a different shape than the contour  70  of the front right feathering plate  68 . In some embodiments, the rear right feathering plate and/or the front right feathering plate  68  may be selected from various elongated shapes to accommodate various components of the agricultural implement  10  (e.g., lug for right actuating cylinder  48 ). 
       FIG. 5  is a front perspective view of an embodiment of the left pivot joint  42  illustrating an extended and reduced stress gradient. The left pivot joint  42  includes a front left working plate  74  coupled to the central tool bar  30  via a bolt  76 . In certain embodiments, the front left working plate  74  may have a thickness of 1, 1.25, or 1.5 inches, although again other thicknesses may be appropriate. Additionally, some embodiments include a front left working plate  74  having a weld edge  78  that is generally flat and/or substantially vertical. As can be appreciated, the left pivot joint  42  and front left working plate  74  may be loaded similar to the right pivot joint  38  of  FIG. 3  when the row units  22  engage the ground. Accordingly, the stress areas  60  on the left inner wing  32  are highest near the bolt  76 . Thus, the weld edge  78  of the left pivot joint  42  may traverse multiple stress areas  60  under various levels of stress. Since the weld connection is made in a stress area  60  of higher stress near the bolt  76  and/or across multiple stress areas  60 , the stress on the weld connection, the left pivot joint  42 , and/or the left inner wing  32  is heightened. 
       FIG. 6  is a front perspective view of an embodiment of the left pivot joint  42  with a front left feathering plate  80  illustrating a stress gradient. In certain embodiments, the front left feathering plate  80  may have a thickness (e.g., 1, 0.75, 0.5, 0.375, or less inches) less than the front left working plate  74 . Moreover, the front left feathering plate  80  includes a contour  82  and a contoured tip  84 . In certain embodiments, the front left feathering plate  80  may include a contour  82  having a different shape than the shape of the contour  70  of the front right feathering plate  68 . For example, some embodiments of the agricultural implement  10  may include front right and front left feathering plates  68  and  82  having different shapes to accommodate various components of the agricultural implement  10  (e.g., lug for left actuating cylinder  52 ). Moreover, the front left feathering plate  80  is welded to the front left working plate  74  at the weld edge  78  and/or another edge. Additionally, the front left feathering plate  80  is welded to the left inner wing  32  at or around the contoured tip  84 . In certain embodiments, the front left working plate  74  and the front left feathering plate  80  may be welded before or after welding connections between the front left feathering plate  80  and the left inner wing  32  are joined. In other embodiments, the front left feathering plate  80  and the front left working plate  74  may be physically stacked and concurrently welded to each other and the left inner wing  32 . 
     As previously discussed, by locating a welded connection to the left inner wing  32  and the front left feathering plate  80  further from the bolt  76 , the weld is connected at a stress area  60  of less stress than the weld connection in  FIG. 5  thereby reducing the risk of failure of the weld when the row units  22  engage the soil during operation of the agricultural implement  10 . Furthermore, by distributing the stress from the bolt  76  across the front left feathering plate  80 , weld connections at the weld edge  78  and/or other locations around the front right working plate  74  are subjected to less stress in  FIG. 6  that in  FIG. 5 . 
     Moreover, the left pivot joint  42  includes a rear connection between the central tool bar  30  and the left inner wing  32  using rear left feathering plate  86 . In certain embodiments, the rear left feathering plate  86  may have a different shape than that of the front left feathering plate  80  to accommodate various connections for the agricultural implement (e.g., lug for the left actuating cylinder  52 ). Furthermore, in some embodiments, the front right feathering plate  68  has the same shape as the rear left feathering plate  86 , and the front left feathering plate  80  has the same shape as the rear right feathering plate. While the foregoing discussion related only to the right pivot joint  38  and the left pivot joint  42 , similar feathering plates and/or working plates may be used in the right outer pivot joint  36  and/or the left outer pivot joint  40 . 
     While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.