Abstract:
A coulter assembly is provided that facilitates continuous adjustment of coulter disk penetration depth. In an exemplary embodiment, the coulter assembly includes a gauge wheel configured to rotate across a soil surface to limit a penetration depth of a coulter disk into the soil. A depth adjustment assembly is coupled to the gauge wheel and configured to adjust the penetration depth of the coulter disk by continuously varying the vertical position of the gauge wheel. This configuration may enable the coulter disk to operate at any penetration depth within the gauge wheel range of motion, thereby facilitating deposition of fertilizer within the soil at a suitable depth to enhance crop growth.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional of U.S. patent application Ser. No. 12/474,408, entitled “Coulter Assembly”, filed May 29, 2009, now U.S. Pat. No. 8,047,147, which is herein incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     The invention relates generally to a coulter assembly, and more specifically, to a continuously variable depth adjustment system for altering a coulter disk penetration depth. 
     Generally, coulters are towed behind a tractor via a mounting bracket secured to a rigid frame of the implement. Coulters are typically configured to excavate a trench into soil, and may assist in delivering a liquid or dry fertilizer into the trench. Specifically, certain coulters include a coulter disk that cuts into the soil as the coulter moves along the terrain. A penetration depth of the coulter disk is generally regulated by a gauge wheel. In a typical configuration, the gauge wheel is positioned adjacent to the coulter disk and rotates across the soil surface. The coulter disk is positioned below the gauge wheel such that the coulter disk penetrates the soil. A vertical offset distance between the coulter disk and the gauge wheel determines the coulter disk penetration depth. As will be appreciated by those skilled in the art, the effectiveness of fertilizer may be dependent upon its deposition depth within the soil. Therefore, precise control of coulter disk penetration depth may be beneficial for crop growth. 
     However, typical coulter assemblies only facilitate gauge wheel adjustment in discrete increments. For example, the gauge wheel may only be adjusted between two or three discrete positions. As a result, the coulter may not deposit the fertilizer at a suitable depth to enhance crop growth. 
     BRIEF DESCRIPTION 
     The present invention provides a coulter assembly configured to facilitate continuous adjustment of coulter disk penetration depth. In an exemplary embodiment, the coulter assembly includes a support structure and a coulter disk rotatable coupled to the support structure. A gauge wheel is movably coupled to the support structure and configured to rotate across a surface of the soil to limit a penetration depth of the coulter disk into the soil. A depth adjustment assembly is coupled to the gauge wheel and configured to adjust the penetration depth of the coulter disk by continuously varying the vertical position of the gauge wheel. This configuration enables any coulter disk penetration depth to be selected within the gauge wheel range of motion, thereby facilitating deposition of fertilizer within the soil at a suitable depth to enhance crop growth. 
    
    
     
       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 a towable agricultural implement including multiple coulter assemblies; 
         FIG. 2  is a detailed perspective view of one coulter assembly, as shown in  FIG. 1 ; 
         FIG. 3  is a left side view of the coulter assembly of  FIG. 2 , showing a support structure, a coulter disk, a gauge wheel, and a swing arm; 
         FIG. 4  is an exploded view of the coulter assembly of  FIG. 2 , showing the support structure, the coulter disk, the gauge wheel, and the swing arm; 
         FIG. 5  is a right side view of the coulter assembly of  FIG. 2 , showing the support structure and a depth adjustment assembly; and 
         FIG. 6  is an exploded view of the coulter assembly of  FIG. 2 , showing the support structure and the depth adjustment assembly. 
     
    
    
     DETAILED DESCRIPTION 
     Turning now to the drawings,  FIG. 1  is a perspective view of a towable agricultural implement  10  including multiple left-handed coulter assemblies  12  and right-handed coulter assemblies  14 . As discussed in detail below, the coulter assemblies  12  and  14  may include a coulter disk configured to excavate a trench into soil. A fertilizer delivery assembly positioned behind the coulter disk may then inject a liquid or dry fertilizer into the trench. In such an arrangement, seeds planted adjacent to the trench may receive a proper amount of fertilizer. As illustrated, the coulter assemblies  12  and  14  are secured to shanks  16  that couple the coulter assemblies  12  and  14  to a tool bar  18 . In the present embodiment, the tool bar  18  includes  12  left-handed coulter assemblies  12  and  12  right-handed coulter assemblies  14 . Further embodiments may include more or fewer coulter assemblies  12  and  14 . For example, certain embodiments may include 2, 4, 6, 8, 10, 14, 16, or more left-handed coulter assemblies  12  and right-handed coulter assemblies  14 . The tool bar  18  is coupled to a tow bar  20 , including a hitch  22 . The hitch  22  may, in turn, be coupled to a tractor such that the towable agricultural implement  10  may be pulled through a field. In certain embodiments, the tool bar  18 , including the coulter assemblies  12  and  14 , precedes row units configured to deposits seeds into the soil. In such embodiments, the row units may be offset from the coulter assemblies  12  and  14  such that the seeds are deposited a desired distance from the fertilizer enriched trench. This configuration may enable the crops to absorb a proper amount of fertilizer as they grow. 
     As discussed in detail below, a penetration depth of each coulter disk may be varied by adjusting a vertical position of a gauge wheel. Specifically, the gauge wheel may rotate across a surface of the soil to limit coulter disk penetration. Increasing or decreasing the vertical position of the gauge wheel with respect to the coulter disk varies the penetration depth. In the present embodiment, a depth adjustment assembly is coupled to the gauge wheel to continuously vary its vertical position. Therefore, any coulter disk penetration depth within the gauge wheel range of motion may be selected. 
       FIG. 2  is a detailed perspective view of a left-handed coulter assembly  12 . The coulter assembly  12  is coupled to the shank  16  by a tool bar mount  24 . As illustrated, the tool bar mount  24  is rotatably coupled to a support structure  26  by a shaft  28 . The shaft  28  enables the support structure  26  to rotate about an axis  30  in a direction  32  in response to obstructions or variations in the terrain. Specifically, the tool bar mount  24  may be coupled to the shank  16  by fasteners that pass through openings  34  in the tool bar mount  24 . The tool bar mount  24  includes a spring plate  36  configured to limit rotation of the support structure  26  with respect to the tool bar mount  24 . The coulter assembly  12  includes a threaded rod  38  and a compression spring  40  configured to maintain a substantially constant force between the gauge wheel and the soil. Specifically, the threaded rod  38  passes through an opening in the spring plate  36 , and the spring  40  is disposed about the threaded rod  38 . A first spring stop  42  is disposed between the spring  40  and the spring plate  36 , and a second spring stop  44  is disposed adjacent to the opposite end of the spring  40  to ensure that the spring  40  remains disposed about the threaded rod  38 . The second spring stop  44  is secured to the spring  40  by a washer  46  and a pair of fasteners  48 . The threaded rod  38  is coupled to a pin  50  that passes through a hole  52  in the support structure  26 . The pin  50  is secured to the threaded rod  38  by a loop  54  and the support structure  26  by a cotter pin  56 . 
     The structure described above enables the support structure  26  to rotate about the axis  30  in the direction  32  in response to variations in field conditions. For example, if the support structure  26  is driven to rotate in the direction  32  by contact with an obstruction, the support structure  26  may rotate about the shaft  28 . As the support structure  26  rotates, the spring  40  is compressed, thereby biasing the support structure  26  toward its initial orientation. Specifically, rotation of the support structure  26  causes the pin  50  to rotate about the axis  30  in the direction  32 . Because the pin  50  is coupled to the threaded rod  38  by the loop  54 , the threaded rod  38  is driven to translate through the opening in the spring plate  36 . The spring  40  is then compressed between the spring stops  42  and  44  by the washer  46  secured to the threaded rod  38  by the fasteners  48 . The spring compression applies a biasing force to the support structure  26  by the previously described linkage, thereby inducing the support structure  26  to return to its initial orientation. Such a configuration may serve to protect the coulter assembly  12  by absorbing the impact of obstructions encountered during cultivation. 
     The coulter assembly  12  also includes a coulter disk  58  rotatably coupled to the support structure  26  by a bearing assembly  60 . The bearing assembly  60  enables the coulter disk  58  to freely rotate as it engages the soil and excavates a trench. The coulter assembly  12  also includes a scraper  62  disposed adjacent to the coulter disk  58  and coupled to the support structure  26  by a bracket  64 . The scraper  62  is configured to remove accumulated soil from the coulter disk  58  and may serve to widen the trench. The scraper  62  is coupled to a fertilizer tube  66  configured to deliver liquid or dry fertilizer into the trench. 
     A gauge wheel  68  is pivotally coupled to the support structure  26  by a swing arm  70 . The swing arm  70  is, in turn, coupled to a depth adjustment assembly  72  configured to continuously vary the vertical position of the gauge wheel  68  with respect to the support structure  26 . As discussed in detail below, because the gauge wheel  68  travels along the surface of the soil, varying the position of the gauge wheel  68  alters the penetration depth of the coulter disk  58  into the soil. The depth adjustment assembly  72  includes a lever  74  and a shaft  76 . The shaft  76  is rigidly coupled to a first end of the lever  74 , and a linear actuator is coupled to the second end. In this configuration, extension and retraction of the linear actuator induces the lever  74  and the shaft  76  to rotate. In certain embodiments, the linear actuator may include a pneumatic cylinder, a hydraulic cylinder, or an electromechanical actuator, for example. In the present embodiment, the linear actuator includes a rod  78 , a pin  80 , a mount  82 , a first fastener  84  and a second fastener  86 . As discussed in detail below, adjusting the position of the fasteners  84  and  86  with respect to the rod  78  rotates the lever  74 , thereby rotating the shaft  76  coupled to the swing arm  70 . Rotating the swing arm  70  alters the vertical position of the gauge wheel  68 , thereby varying the penetration depth of the coulter disk  58 . Because the fasteners  84  and  86  may be positioned at any location along the length of the rod  78 , extension and/or retraction of the rod  78  with respect to the mount  82  may be continuously varied. Therefore, any coulter disk penetration depth within a range defined by the length of the rod  78  and the geometry of the depth adjustment assembly  72  may be achieved. 
       FIG. 3  is a left side view of the coulter assembly  12 , showing the support structure  26 , the coulter disk  58 , the gauge wheel  68 , and the swing arm  70 . As previously discussed, the depth adjustment assembly  72  may rotate the swing arm  70 , thereby adjusting the vertical position of the gauge wheel  68 . Specifically, the swing arm  70  includes a first region  88  and a second region  90 . The first region is rigidly coupled to the shaft  76  by a bolt  92 . In this manner, rotation of the shaft  76  induces the swing arm  70  to rotate. In addition, the gauge wheel  68  is rotatably coupled to the second region  90  by a bolt  94 . The bolt  94  enables the gauge wheel  68  to rotate as it moves across the soil surface. 
     In the illustrated embodiment, the gauge wheel  68  includes an outer surface  96  and an inner hub  98 . The outer surface  96  may be composed of rubber to provide traction between the gauge wheel  68  and the soil. The inner hub  98  may be composed of a rigid material (e.g., nylon) capable of supporting the outer surface  96 . As illustrated, a penetration depth D is established between the bottom of the gauge wheel  68  and the bottom of the coulter disk  58 . Specifically, because the gauge wheel  68  rotates along the surface of the soil, the coulter disk  58  may penetrate the soil to the penetration depth D. In addition, because the depth adjustment assembly  72  is configured to lock the swing arm  70  into place during operation of the coulter assembly  12 , the gauge wheel  68  may limit the penetration depth D based on the angle of the swing arm  70 . Moreover, because the depth adjustment assembly  72  is configured to continuously vary the angle of the swing arm  70  with respect to the support structure  26 , the depth adjustment assembly  72  may continuously vary the penetration depth D of the coulter disk  58  into the soil. 
     In the present embodiment, the gauge wheel  68  is disposed directly adjacent to the coulter disk  58 . In this configuration, the gauge wheel  68  may serve to remove accumulated soil from the coulter disk  58  as the gauge wheel  68  rotates. In certain embodiments, the gauge wheel  68  is angled about a longitudinal axis of the support structure  26  toward a soil penetrating portion of the coulter disk  58 . This arrangement may serve to enhance soil removal from the coulter disk  58 . 
       FIG. 4  is an exploded view of the coulter assembly  12 , showing the support structure  26 , the coulter disk  58 , the gauge wheel  68 , and the swing arm  70 . Specifically,  FIG. 4  illustrates the internal parts that enable the swing arm  70  to rotate with respect to the support structure  26 . As previously discussed, the swing arm  70  is rigidly coupled to the shaft  76 . To limit rotation of the swing arm  70  with respect to the shaft  76 , a key  100  is inserted into a recess  102  in the shaft  76 . A bearing  104  is then disposed between the shaft  76  and the support structure  26  to enable the shaft  76  to rotate within the support structure  26 . The first region  88  of the swing arm  70  includes an opening  106  including a recess  108  configured to interlock with the key  100 . Specifically, the recess  108  is aligned with the key  100  prior to disposing the opening  106  about the shaft  76 . Interaction between the key  100  and the recess  108  limits rotation of the swing arm  70  with respect to the shaft  76 . Therefore, rotation of the shaft  76  by the depth adjustment assembly  72  rotates the swing arm  70 , while limiting rotation of the swing arm  70  during operation of the coulter assembly  12 . Finally, the swing arm  70  is secured to the shaft  76  by the bolt  92  and washers  110  and  112 . 
     As previously discussed, the gauge wheel  68  is coupled to the second region  90  of the swing arm  70  by the bolt  94 . Specifically, the bolt  94  passes through the gauge wheel  68  and a washer  114 . The bolt  94  then secures to an opening  116  within the second region  90  of the swing arm  70 . This configuration enables the gauge wheel  68  to rotate with respect to the swing arm  70  as it moves across the soil surface. 
       FIG. 5  is a right side view of the coulter assembly  12 , showing the support structure  26  and the depth adjustment assembly  72 . As previously discussed, the depth adjustment assembly  72  facilitates continuous adjustment of the penetration depth D of the coulter disk  58  into the soil by adjusting the vertical position of the gauge wheel  68 . Specifically, a position of the rod  78  may be varied by adjusting the position of the fasteners  84  and  86  with respect to the mount  82 . In certain embodiments, the rod  78  may be threaded and the fasteners  84  and  86  may be nuts including complementary threads configured to mate with the threaded rod  78 . In such a configuration, washers  118  and  120  may be disposed between the nuts  84  and  86 , respectively, and the mount  82 . For example, the rod  78  may be translated in a direction  122  by uncoupling the fastener  86 , moving the rod  78  in the direction  122 , and then securing both fasteners  84  and  86  about the mount  82 . Translating the rod  78  in the direction  122  rotates the lever  74  in a direction  124 , thereby rotating the shaft  76  in the direction  124 . As previously discussed, the shaft  76  is rigidly coupled to the swing arm  70 . Therefore, rotating the shaft  76  in the direction  124  induces the swing arm  70  to rotate in the direction  124 , thereby increasing the vertical displacement of the gauge wheel  68  with respect to the support structure  26  and increasing the penetration depth D of the coulter disk  58 . 
     Conversely, the rod  78  may be translated in a direction  126  by uncoupling the fastener  84 , moving the rod  78  in the direction  126 , and then securing both fasteners  84  and  86  about the mount  82 . Translating the rod  78  in the direction  126  rotates the lever  74  in a direction  128 , thereby rotating the shaft  76  in the direction  128 . Because the shaft  76  is rigidly coupled to the swing arm  70 , rotating the shaft  76  in the direction  128  induces the swing arm  70  to rotate in the direction  128 . Therefore, the vertical displacement of the gauge wheel  68  with respect to the support structure  26  is decreased, and the penetration depth D of the coulter disk  58  is decreased. In certain embodiments, the penetration depth D of the coulter disk  58  may be continuously varied between approximately 0 to 6 inches. However, further embodiments may have a greater or lesser range of adjustment. Because the fasteners  84  and  86  may be positioned at any location along the rod  78 , any penetration depth D may be established within the range limited by the length of the rod  78  and the geometry of the depth adjustment assembly  72 . 
       FIG. 6  is an exploded view of the coulter assembly  12 , showing the support structure  26  and the depth adjustment assembly  72 . As illustrated, the threaded rod  78  includes a loop  130  configured to receive the pin  80 . The loop  130  of the threaded rod  78  may be aligned with openings  132  in the lever  74 . The pin  80  may then be inserted through the openings  132  and the loop  130  to secure the threaded rod  78  to the lever  74 . The pin  80  includes a recess  134 , and the threaded rod  78  includes an opening  136 . The recess  134  may be aligned with the opening  136 , and a pin  138  may be inserted through the opening  136  and into the recess  134 . In this manner, the threaded rod  78  may be rotatably secured to the lever  74 . 
     As previously discussed, the lever  74  is rigidly coupled to the shaft  76  including the key  100 . A bearing  140  is disposed about the shaft  76  such that the shaft  76  may rotate within an opening  142  within the support structure  26 . This configuration may enable linear movement of the threaded rod  78  to induce rotation of the shaft  76  within the opening  142  such that the swing arm  70  rotates with respect to the support structure  26 . The threaded rod  78  may be inserted through an opening  144  in the mount  82 . As illustrated, the opening  144  is elongated in the vertical direction to enable vertical movement of the threaded rod  78  as the rod  78  translates in the direction  122  and/or  126  through the opening  144  in the mount  82 . As previously discussed, fastener  84  and washer  118  is disposed on one side of the mount  82 , while fastener  86  and washer  120  are disposed on the opposite side. In this configuration, the threaded rod  78  may be positioned and secured relative to the mount  82  such that the vertical position of the gauge wheel  68  may be continuously varied with respect to the support structure  26 , thereby enabling the penetration depth D of the coulter disk  58  to be continuously adjusted. 
     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.