Abstract:
An angle adjustable coulter wheel assembly includes a rotatable shank having a longitudinal axis defined by an upper portion of the shank. The longitudinal axis is oriented neither vertically or horizontally with respect to the ground when the assembly is mounted on a tillage apparatus. A coulter wheel rotatably mounted on the shank proximate a lower portion of the shank. An actuator rotates the upper portion of the shank about the longitudinal axis to cause the face of the coulter wheel to rotate about three orthogonal axes thereby changing orientation of the face of the coulter wheel with respect to the ground when the assembly is on the tillage apparatus. The coulter wheel assembly permits adjusting the angle of the coulter wheel in at least two planes permitting greater control over how much soil the coulter wheel disturbs during tilling.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of International Patent Application PCT/CA2015/050013 filed Jan. 9, 2015, which claims the benefit of U.S. patent application 61/925,402 filed Jan. 9, 2014, the entire contents of which are each hereby incorporated by reference. 
     
    
     FIELD 
       [0002]    This application relates to farm machinery, in particular to coulter wheel assemblies for tillage apparatuses. 
       BACKGROUND 
       [0003]    Apparatuses, systems and methods for tilling agricultural fields are very well known in the art. Apparatuses typically comprise a cultivator frame having multiple and various tilling attachments attached thereto, laid out on the frame in a variety of patterns to maximize the desired tilling effect. The apparatus is dragged behind a vehicle during the tilling operation. 
         [0004]    In particular, conservation tillage, or vertical tillage as it is sometimes called, has recently become a tilling strategy of choice in many instances. Conservation tillage minimally disturbs the soil prior to planting in order to allow air to penetrate the mat of crop residue left in the field from the previous harvest. Apparatuses, systems and methods for conservation tillage are known in the art, for example United States patents U.S. Pat. No. 7,762,345 issued Jul. 27, 2010, U.S. Pat. No. 8,113,295 issued Feb. 14, 2012, U.S. Pat. No. 8,196,672 issue Jun. 12, 2012, U.S. Pat. No. 8,307,908 issued Nov. 13, 2012 and U.S. Pat. No. 8,307,909 issued Nov. 13, 2012, the entire contents of all of which are herein incorporated by reference. 
         [0005]    A tillage apparatus may comprise various attachments for working a field including, for example, coulter wheels, chisel plows, V-shaped shovels, sub-soiling teeth, leveling attachments and other field working tools. The attachments are typically mounted on longitudinal or transverse frame-members of the cultivator frame either individually or in gangs. Coulter wheels are a particularly useful attachment for conservation tillage techniques. However, coulter wheels are typically mounted on the cultivator frame in a fixed position with no opportunity to adjust the entry angle of the wheel into the soil. This limits the versatility of the coulter wheels to efficiently till different soil types and through different soil conditions. Some attempts have been made to overcome this limitation, for example, the Gates Coulter Disk is a vertical tillage tool that is adjustable from 0 to 15 degrees around a single axis of rotation. While this provides some versatility, the angle adjustment is limited to rotation around a single axis providing limited gains in tilling versatility. 
         [0006]    There remains a need in the art for more versatile angle adjustable coulter wheel assemblies. 
       SUMMARY 
       [0007]    There is provided an angle adjustable coulter wheel assembly comprising: a rotatable shank having a longitudinal axis defined by an upper portion of the shank, the longitudinal axis of the upper portion of the shank oriented neither vertically or horizontally with respect to the ground when the assembly is mounted on a tillage apparatus; a coulter wheel rotatably mounted on the shank proximate a lower portion of the shank, the coulter wheel comprising a face and an edge; and, an actuator for rotating the upper portion of the shank about the longitudinal axis, wherein rotation of the shank about the longitudinal axis of the upper portion of the shank causes the face of the coulter wheel to rotate about three orthogonal axes thereby changing orientation of the face of the coulter wheel with respect to the ground when the assembly is mounted on a tillage apparatus. 
         [0008]    There is also provided a tillage apparatus comprising a cultivator frame and at least one angle adjustable coulter wheel assembly as described above mounted on the cultivator frame. 
         [0009]    There is also provided a method of tilling a field comprising dragging the tillage apparatus as described above across the field with the coulter wheels of the at least one coulter wheel assembly engaged with soil in the field. 
         [0010]    The coulter wheel assembly is typically mounted on a cultivator frame of a tillage apparatus. The cultivator frame has a longitudinal axis in the direction of motion of the tillage apparatus as it is being dragged across the ground (e.g. a field). The longitudinal axis of the cultivator frame runs from front to rear (or rear to front) of the frame. The cultivator frame has a transverse axis that is perpendicular to the longitudinal axis of the cultivator frame and runs left to right (or right to left) of the frame. The front end of the frame is mounted to the transportation (e.g. vehicle) that drags the apparatus. The cultivator frame may have having a plurality of longitudinally spaced apart transverse frame members and a plurality of transversely spaced apart longitudinal frame members. 
         [0011]    In the angle adjustable coulter wheel assembly, the lower portion of the shank may be transversely offset from the longitudinal axis of the upper portion of the shank. The upper and lower portions of the shank may be in substantially parallel planes or be angled such that a longitudinal axis through the lower portion would cross the longitudinal axis through the upper portion. The upper and lower portions of the shank may be connected such that rotation of the upper portion of the shank causes rotation of the lower portion of the shank. Preferably, the upper portion of the shank is rigidly connected to the lower portion of the shank. 
         [0012]    The upper and lower portions of the shank may be connected by an intermediate portion of the shank. The intermediate portion of the shank may form any suitable angles with the upper and lower portion of the shank, the angle between the intermediate portion and upper portion and the angle between the intermediate portion and the lower portion being the same or different. The intermediate portion of the shank may be angled away from the longitudinal axis of the shank. 
         [0013]    The shank may comprise a single piece of material, for example a tube or bar, or a plurality of pieces of material connected together. The shank may have at least two spaced-apart elbows along a length of shank. A first elbow may direct the shank away from the longitudinal axis of the upper portion of the shank. A second elbow closer to the lower portion of the shank may direct the shank at least partially back toward the longitudinal axis of the upper portion of the shank but longitudinally away from the upper portion of the shank. The first and second elbows may form substantially 90° angles, although any angles that permit rotation of the shank to usefully orient the face of the coulter wheel are suitable. The shank may have third, fourth or more elbows depending on the most efficient configuration for the coulter wheel assembly. 
         [0014]    The coulter wheel assembly may be mounted on the tillage apparatus at any suitable location, for example on a transverse or longitudinal frame member of the cultivator frame. The assembly may be mounted with any suitable mount, for example a bracket, a weld, a bolt, etc. Any part of the assembly may be mounted on the tillage apparatus. Preferably, the upper portion of the shank may be mounted on the tillage apparatus using a shank mount. The shank mount is preferably a bracket that supports the upper portion of the shank while permitting the upper portion of the shank to rotate under the control of the actuator. 
         [0015]    The coulter wheel may be any suitable type of coulter wheel, for example rippled, waved, straight or concave coulter wheels, or the coulter wheel may be some other form of disk tool such as a disk harrow. The coulter wheel may comprise a hub rotatably mountable on a shaft, the shaft providing an axle on which the coulter wheel may rotate. The shaft may extend from the lower portion of the shank, preferably toward the longitudinal axis of the upper portion of the shank. At least a majority of the face of the coulter wheel may be between the lower portion of the shank and the longitudinal axis of the upper portion of the shank. Depending on the shape of the coulter wheel and/or the angle that the face of the coulter wheel makes with a horizontal and/or vertical plane, a portion of the face of the coulter wheel may not be between the lower portion of the shank and the longitudinal axis of the upper portion of the shank. The angle of the coulter wheel is adjustable about three orthogonal spatial axes and in at least two planes, a horizontal plane parallel to the ground and defined by the longitudinal and transverse frame members of the cultivator frame and a vertical plane perpendicular to the horizontal plane and containing the longitudinal axis of the cultivator frame. The face of the coulter wheel can form almost any angle with these planes depending on the actuator used to rotate the shank and on any desired constraints placed on the amount of rotation that the upper portion of the shaft may undergo. In an embodiment, the angle that the face of the coulter wheel can make with one or both of the vertical and horizontal planes may be adjustable through an amount up to about 30 degrees, preferably up to about 25 degrees. In an embodiment, horizontal angle range may be from about −5 degrees to about 20 degrees with respect to a normal to the horizontal plane. In an embodiment, vertical angle range may be from about −5 degrees to about 20 degrees with respect to the vertical plane. 
         [0016]    In a tillage operation, the coulter wheel contacts soil and rotation of the coulter wheel in the soil permits cutting through residue. When the face of the coulter wheel is in the vertical plane and perpendicular to the horizontal plane, minimum tillage is obtained. As the face of the coulter wheel is rotated away from the vertical plane and away from being perpendicular to the horizontal plane, more tillage action is obtained. However, rotating the face of the coulter wheel can shift the point at which the coulter wheel contacts the soil. In such a case, tillage lines in a field would not be straight if the angle of the face of the coulter wheel was changed during tillage. To ensure that tillage lines remain straight whether or not the angle of the face of the coulter wheel is changed, the coulter wheel assembly may be designed so that a point of first ground contact on the coulter wheel is on the longitudinal axis of the upper portion of the shank. Regardless of the nature of the shank or mounting structures thereon, regardless of the angle of the longitudinal axis, regardless of the angle of the face of the coulter wheel and regardless of the relative orientations of the upper and lower portions of the shank, if the point of first contact of the coulter wheel with the soil is on the longitudinal axis, the point of first contact remains constant and tillage lines will be straight and evenly spaced. This is especially useful for tillage apparatuses in which left hand and right hand concave coulter wheel assemblies are employed. When concave coulter wheels are used, left hand and right hand coulter wheels are needed to balance side forces so that the apparatus pulls straight. Keeping the point of first contact constant for all coulter wheels is therefore important so that the coulter wheels remain evenly spaced and can be uniformly rotated for both the left and right hand assemblies thereby keeping the spacing or line of cut constant in a longitudinal direction of the cultivator. 
         [0017]    The actuator may be manual or powered. Manual actuators include, for example, hand cranks, levers, and the like. Powered actuators include, for example, hydraulic, electric or pneumatic actuators. Hydraulic actuators are preferred. The actuator may be controlled locally at the assembly, or remotely. Preferably, the actuator may be controlled remotely, for example from a cab of transportation drawing the tillage apparatus or from a different remote location using wireless connections to control operations of the tillage apparatus. The tillage apparatus may comprise needed electricity supplies, electrical connections, fluid reservoirs, fluid pumps and/or fluid lines to provide for control of the actuator. Preferably, the actuator may be controlled while the tillage apparatus is moving so that the angle of the coulter wheel may be adjusted on the fly. 
         [0018]    The actuator may be operatively connected to the shank at any suitable location along the shank, for example the upper portion of the shank or the intermediate portion of the shank. In the case of a hydraulic actuator, extension of an actuator rod may cause rotation of the upper portion of the shank about the longitudinal axis. The rod may be connected to the upper portion of the shank or the intermediate portion of the shank by a linkage arm. The linkage arm may be rigidly connected to the shank and pivotally connected to the actuator rod, or pivotally connected to both the shank and the actuator rod. The actuator may be mounted at any suitable location on the tillage apparatus, for example a transverse or longitudinal frame member of the cultivator frame. The actuator may be mounted on the tillage apparatus using any suitable mount, for example, a bracket, a weld, a bolt, etc. 
         [0019]    The angle adjustable coulter wheel assembly may further comprise a safety mechanism for protecting the coulter assembly from being damaged by forces caused when the coulter wheel assembly is deflected by striking a hard and/or immovable object such as a rock. The safety mechanism may comprise one or more resilient elements, for example, resilient blocks, bushings and/or shank portions. A resilient element may comprise any suitable resilient material, for example an elastomer (e.g. rubber) or spring steel. One embodiment of a suitable safety mechanism is described in U.S. Pat. No. 8,365,837 issued Feb. 5, 2013, the entire contents of which is herein incorporated by reference. 
         [0020]    The angle adjustable coulter wheel assembly may be used with any tillage apparatus, for example the tillage apparatus described in U.S. Pat. No. 8,307,909 issued Nov. 13, 2012, the entire contents of which is herein incorporated by reference. No-till or conservation tillage apparatuses are preferred. The tillage apparatus may comprise a plurality of coulter wheel assemblies. Coulter wheel assemblies may be mounted individually and/or in gangs. The coulter wheel assemblies in gangs may be individually controlled, for example by employing an actuator with each coulter wheel assembly. Two or more of the coulter wheel assemblies in a gang may be controlled by a single actuator. One actuator may effect rotation of the upper portion of the shanks of at least two coulter wheel assemblies. The coulter wheel assemblies may be mounted on the apparatus in transverse rows, longitudinal rows, randomly or any combination thereof. In one embodiment, the coulter wheel assemblies may be mounted in 1 or more transverse rows, for example 1 or more rows, 2 or more rows, 3 or more rows, 4 or more rows, or 5 or more rows. 
         [0021]    When the tillage apparatus is being dragged across a field, the orientation of the face of the coulter wheel with respect to the field may be changed in both a horizontal plane and a vertical plane. This permits the coulter wheel to be more engaged or less engaged with soil in the field depending on soil conditions. The ability to change the orientation of the coulter wheel while the tillage apparatus is moving is particularly useful. Thus, the coulter wheel assembly permits adjusting the angle of the coulter wheel in at least two planes permitting greater control over how much soil the coulter wheel disturbs during tilling. 
         [0022]    Further features will be described or will become apparent in the course of the following detailed description. It should be understood that each feature described herein may be utilized in any combination with any one or more of the other described features, and that each feature does not necessarily rely on the presence of another feature except where evident to one of skill in the art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]    For clearer understanding, preferred embodiments will now be described in detail by way of example, with reference to the accompanying drawings, in which: 
           [0024]      FIG. 1  depicts a perspective view of one embodiment of an angle adjustable coulter wheel assembly; 
           [0025]      FIG. 2A  depicts a top view of the coulter wheel assembly of  FIG. 1  with the coulter wheel angled in a first position; 
           [0026]      FIG. 2B  depicts a top view of the coulter wheel assembly of  FIG. 1  with the coulter wheel angled in a second position; 
           [0027]      FIG. 3A  depicts front view of the coulter wheel assembly of  FIG. 2A ; 
           [0028]      FIG. 3B  depicts front view of the coulter wheel assembly of  FIG. 2B ; 
           [0029]      FIG. 4A  depicts side view of the coulter wheel assembly of  FIG. 2A ; 
           [0030]      FIG. 4B  depicts side view of the coulter wheel assembly of  FIG. 2B ; 
           [0031]      FIG. 5A  depicts a perspective view of a gang comprising three coulter wheel assemblies of  FIG. 1 ; 
           [0032]      FIG. 5B  depicts a top view of the gang of coulter wheel assemblies of  FIG. 5A  with the coulter wheels angled in a first position; 
           [0033]      FIG. 5C  depicts a top view of the gang of coulter wheel assemblies of  FIG. 5A  with the coulter wheels angled in a second position; 
           [0034]      FIG. 6  depicts a perspective view of another embodiment of an angle adjustable coulter wheel assembly; 
           [0035]      FIG. 7A  depicts a top view of the coulter wheel assembly of  FIG. 6  with the coulter wheel angled in a first position; 
           [0036]      FIG. 7B  depicts a top view of the coulter wheel assembly of  FIG. 6  with the coulter wheel angled in a second position; 
           [0037]      FIG. 8A  depicts front view of the coulter wheel assembly of  FIG. 7A ; 
           [0038]      FIG. 8B  depicts front view of the coulter wheel assembly of  FIG. 7B ; 
           [0039]      FIG. 9A  depicts side view of the coulter wheel assembly of  FIG. 7A ; 
           [0040]      FIG. 9B  depicts side view of the coulter wheel assembly of  FIG. 7B ; 
           [0041]      FIG. 10A  depicts a perspective view of a gang comprising four coulter wheel assemblies of  FIG. 6 ; 
           [0042]      FIG. 10B  depicts a top view of the gang of coulter wheel assemblies of  FIG. 10A  with the coulter wheels angled in a first position; 
           [0043]      FIG. 10C  depicts a top view of the gang of coulter wheel assemblies of  FIG. 10A  with the coulter wheels angled in a second position; 
           [0044]      FIG. 11A  depicts a front view of the coulter wheel assembly of  FIG. 6  with a wavy coulter wheel instead of a concave coulter wheel and with the coulter wheel angled in a first position; 
           [0045]      FIG. 11B  depicts a front view of the coulter wheel assembly of  FIG. 6  with a wavy coulter wheel instead of a concave coulter wheel and with the coulter wheel in a straight-up position; 
           [0046]      FIG. 11C  depicts a front view of the coulter wheel assembly of  FIG. 6  with a wavy coulter wheel instead of a concave coulter wheel and with the coulter wheel angled in a second position; and, 
           [0047]      FIG. 12  depicts an enlarged view of an underside of a lower shank portion of a coulter wheel assembly without a coulter wheel. 
       
    
    
     DETAILED DESCRIPTION 
       [0048]    Referring to  FIG. 1 ,  FIG. 2A ,  FIG. 2B ,  FIG. 3A ,  FIG. 3B ,  FIG. 4A  and  FIG. 4B , one embodiment of a coulter wheel assembly  1  is shown comprising a shank  10  having an upper shank section  11  mounted on a transverse frame element  90  of a cultivator frame with a mounting bracket  50 . The mounting bracket  50  may comprise any suitable structures to engage the transverse frame element  90  and shank  10 , for example U-bolts  51  to secure the mounting bracket  50  to the transverse frame element  90  and spaced-apart bracket arms  52  with a receiving tube  53  secured there between (as best seen in  FIG. 4A  and  FIG. 4B ) within which the upper shank section  11  of the shank  10  is supported. The upper shank section  11  is free to rotate within the receiving tube  53  and the receiving tube  53  may be secured between the spaced-apart bracket arms  52  by any suitable method, preferably by welding. The arrows labeled “FRONT” in  FIG. 1 ,  FIG. 2A ,B and  FIG. 4A ,B indicate the direction of the front of the cultivator frame, i.e. the direction of movement of the cultivator frame when the tillage apparatus is being dragged across a field. 
         [0049]    The coulter wheel assembly  1  further comprises a coulter wheel  20  having a hub  21  rotatably mounted on an axle  22  extending from a lower shank section  13  of the shank  10 . The coulter wheel may be any type of coulter wheel, for example rippled, waved, straight or concave coulter wheels, or the coulter wheel may be some other form of disk tool such as a disk harrow. The coulter wheel  20  is depicted as a concave coulter wheel. The upper shank section  11  is connected to the lower shank section  13  by a middle shank section  12  that forms a double elbow  14 ,  15  between the upper and lower shank sections  11 ,  13 , respectively, so that the upper and lower shank sections  11 ,  13  are transversely offset. It is evident to one skilled in the art that the lower shank section  13  may be substantially parallel to the upper shank section  11  but does not need to be, and that each of the elbows may be any suitable angle to provide the desired orientation of the lower shank section  13  in relation to the upper shank section  11 . 
         [0050]    The shank  10  is oriented to generally point downward and to a front of the cultivator frame. Thus, the orientation of the shank  10  is generally perpendicular to the transverse frame element  90  but is not orthogonal to or parallel with the longitudinal axis of the cultivator frame. Thus, longitudinal axis A of the upper shank section  11  is also not orthogonal to or parallel with the longitudinal axis of the cultivator frame, but is perpendicular to the transverse frame element  90 . The lower shank section  13  is thus transversely offset from the longitudinal axis A of the upper shank section  11 . The longitudinal axis A of the upper shank section  11  preferably forms an angle in a range of from about 30 degrees to about 60 degrees with the longitudinal axis of the cultivator frame. 
         [0051]    To be able to rotate the shank  10 , a hydraulic cylinder  30  mounted on the transverse frame element  90  is linked to the upper shank section  11  of the shank  10 . The hydraulic cylinder  30  is rigidly mounted on the transverse frame element  90  by mounting flange  31 . A cylinder rod  34  of the hydraulic cylinder  30  is pivotally linked to a rotatable arm  32  by pivot pin  33  and the rotatable arm  32  is secured, for example by welding, to the upper shank section  11 . In the embodiment shown in the Figures, the rotatable linkage arm  32  may comprises two spaced-apart parallel arm portions where both arm portions are secured to the upper shank section  11  for greater security. The hydraulic cylinder may be powered by a hydraulic fluid pump hydraulically connected to the cylinder by fluid lines. Hydraulic connections for tillage implements are well known in the art. Although a hydraulic cylinder is particularly exemplified, it is evident that any form of actuator may be employed, for example manual actuators such as hand cranks, or other powered actuators such as electric or pneumatic actuators. 
         [0052]    The coulter wheel  20  has two opposed faces  23 ,  25  and an edge  24 . When the rod  34  of the hydraulic cylinder  30  is fully retracted as shown in  FIG. 2A ,  FIG. 3A  and  FIG. 4A , the coulter wheel  20  is in a first orientation whereby the faces  23 ,  25  are substantially oriented in a first plane having a first angular relationship to a horizontal plane defined by the longitudinal and transverse frame elements of the cultivator frame and a vertical longitudinal plane perpendicular to the horizontal plane. When the rod  34  of the hydraulic cylinder  30  extends, the rotatable arm  32  at the pivot pin  33  begins to translate through an arcuate path about the longitudinal axis A of the upper shank section  11 . Because the rotatable arm  32  is secured to the upper shank section  11 , arcuate movement of the rotatable arm  32  causes the upper shank section  11  to rotate about the longitudinal axis A. This rotation is counterclockwise as depicted in  FIG. 2B ,  FIG. 3B  and  FIG. 4B  but the direction of rotation depends on viewer perspective and on which side of the coulter wheel assembly the hydraulic cylinder is mounted. Rotation of the upper shank section  11  causes the lower shank section  13  to move. Because the lower shank section  13  is transversely offset in relation to the upper shank section  11  and because the middle shank section  12  connecting the lower shank section  13  to the upper shank section  11  provides for elbows that change the angular orientation of the shank  10  at intervals along the length of the shank  10 , the simple rotational movement of the upper shank section  11  around one axis (i.e. the longitudinal axis A) translates into a more complicated movement of the lower shank section  13  around three orthogonal spatial axes. The movement of the lower shank section  11  translates to a movement of the coulter wheel  20  around the three orthogonal spatial axes as well, such that the coulter wheel  20  comes to occupy a second orientation as shown in  FIG. 2B ,  FIG. 3B  and  FIG. 4B  whereby the faces  23 ,  25  are substantially oriented in a second plane having a second angular relationship to the horizontal plane defined by the longitudinal and transverse frame elements of the cultivator frame and the vertical longitudinal plane perpendicular to the horizontal plane. The second orientation of the coulter wheel is angularly different about the three orthogonal spatial axes than the first orientation, thus the coulter wheel  20  has rotated about three axes instead of one axis. Therefore, the faces  23 ,  25  of the coulter wheel  20  have rotated in both the horizontal and vertical planes. Retraction of the cylinder rod  34  reverses the motions and ultimately returns the coulter wheel  20  to the first orientation. 
         [0053]    The coulter wheel  20  is therefore adjustable in two planes and three axes and can engage soil in a various ways depending on the extent of rotation of the upper shank section  11 , which in turn depends on how far the cylinder rod  34  extends. It is evident that with appropriate choice of actuator and appropriate design of how the actuator is coupled to the shank, the upper shank section can be made to rotate through any angle thereby providing great flexibility and variation in the orientation of the coulter wheel. Preferably, the orientation of the coulter wheel is adjustable through a range of angles from about −5 degrees to about 20 degrees with respect to a normal to the horizontal plane and from about −5 degrees to about 20 degrees with respect to the vertical plane. 
         [0054]    While a variety of actuators may be employed, the use of powered actuators permits an operator to change coulter wheel orientation on the fly. For example, with a hydraulic cylinder actuator, an operator in a cab of the transportation can set the coulter wheel orientation as desired to match upcoming soil conditions without the need to stop the tillage apparatus. When minimal soil disturbance is desired, the coulter wheel may be oriented straighter and more vertically as depicted in  FIG. 2A ,  FIG. 3A  and  FIG. 4A . When greater soil disturbance is desired, the coulter wheel may be angled more out of the horizontal and vertical planes as depicted in  FIG. 2B ,  FIG. 3B  and  FIG. 4B . The orientation of the coulter wheels may be customized to meet specific needs. 
         [0055]    Coulter wheel assemblies may be mounted on a transverse frame element in gangs. Each coulter wheel assembly in the gang may be individually controlled, for example each having its own actuator. Individual control of the coulter wheel assemblies permits orienting each coulter wheel differently if desired. 
         [0056]    If there is no need or desire to provide individually controlled coulter wheel assemblies, two or more of the coulter wheel assemblies may share an actuator so that the two or more assemblies are controllable simultaneously in the same manner. In one embodiment referring to  FIG. 5A ,  FIG. 5B  and  FIG. 5C , a gang of three coulter wheel assemblies  100 ,  110 ,  120  are shown mounted on a single transverse frame element  900 . The coulter wheel assemblies  100 ,  110 ,  120  are the same and are the same design as the one depicted in  FIG. 1 . A cylinder rod  334  of a single hydraulic cylinder  300  is pivotally linked to a rotatable arm  102  of the coulter wheel assembly  100  and rotatable arms  102 ,  112 ,  122  of the three coulter wheel assemblies  100 ,  110 ,  120 , respectively, are linked together by a linkage bar  350 . Linear movement of the cylinder rod  334  causes pivoting of the rotatable arm  102 , which in turn causes linear translation of the linkage bar  350 . Linear translation of the linkage bar  350  causes pivoting of the rotatable arms  112 ,  122  by the same amount and in the same direction as the pivoting of the rotatable arm  102 . As previously described, rotation of the rotatable arms  102 ,  112 ,  122  ultimately causes coulter wheels  106 ,  116 ,  126 , respectively, to change orientations. The three coulter wheels in the gang have the same orientation with respect to each other. 
         [0057]    Referring to  FIG. 6 ,  FIG. 7A ,  FIG. 7B ,  FIG. 8A ,  FIG. 8B ,  FIG. 9A  and  FIG. 9B , another embodiment of a coulter wheel assembly  1000  is shown comprising a shank  1010  having an upper shank section  1011  mounted on a transverse frame element  1090  of a cultivator frame with a mounting bracket  1050 . The mounting bracket  1050  may comprise any suitable structures to engage the transverse frame element  1090  and shank  1010 , for example mounting plate  1051  to secure bracket arm  1052  to the transverse frame element  1090  with a receiving tube  1053  secured to the bracket arm  1052 . The upper shank section  1011  of the shank  1010  is supported within the receiving tube  1053 . The upper shank section  1011  is free to rotate within the receiving tube  1053  and the receiving tube  1053  may be secured to the bracket arm  1052  by any suitable method, preferably by welding. The arrows labeled “FRONT” in  FIG. 6 ,  FIG. 7A ,B and  FIG. 9A ,B indicate the direction of the front of the cultivator frame, i.e. the direction of movement of the cultivator frame when the tillage apparatus is being dragged across a field. 
         [0058]    The coulter wheel assembly  1000  further comprises a coulter wheel  1020  having a rim  1021  rotatably mounted on an axle  1022  extending from a lower shank section  1013  of the shank  1010 . The coulter wheel may be any type of coulter wheel, for example rippled, waved, straight or concave coulter wheels, or the coulter wheel may be some other form of disk tool such as a disk harrow. The coulter wheel  1020  is depicted as a concave coulter wheel. The upper shank section  1011  is connected to the lower shank section  1013  by a middle shank section  1012 . While the upper shank section  1011  is a cylindrical bar, the middle shank section  1012  is a rectangular tube connected to the upper shank section  1011  by a pair of elbow brackets  1014 . The lower shank section  1013  is a flat bent bar connected to the middle shank section  1014  by an elbow  1015  attached through a pivot pin  1041  to a lower shank mount  1016  proximate an end of the middle shank section  1012 . The upper shank section  1011  and a lower end of the lower shank section  1013  are transversely offset from each other. 
         [0059]    The lower shank section  1013  and/or the elbow  1015  may be at least partially made of spring steel. The lower shank mount  1016  comprises the pivot pin  1041  mounted thereto with a resilient bushing (not shown) mounted thereon, which may be able to deform upon lateral deflection of the lower shank section  1013  thereby absorbing some of the load that would otherwise be transferred to the pivot pin  1041 . The bushing may be pre-compressed and/or may be provided with a clockwise or counter-clockwise bias to aid in resisting pivoting movement of the pivot pin  1041 . The bushing may provide the added benefit of reducing wear caused by ingress of dirt to the pivot pin  1041 . However, in the present application, the resilient bushing may be of limited use as it may become virtually non-compressible due to side load forces. A resilient block  1043  may also be provided between an upper mounting portion of the lower shank mount  1016  and the elbow  1015 , which provides further absorption of loads caused when the coulter wheel assembly  1000  is deflected. By providing the lower shank section  1013  and/or the elbow  1015  with at least a resilient portion and also by providing the resilient block  1043 , the coulter wheel assembly  1000  is able to absorb lateral deflection due to impact with obstacles (e.g. rocks) and also rearward vertical deflection, thereby mitigating impact damage to the coulter wheel assembly  1000  regardless of the angle at which the obstacle is struck. This permits higher speeds to be used without excessive breakage. 
         [0060]    The shank  1010  is oriented to generally point downward and to a front of the cultivator frame. Thus, the orientation of the shank  1010  is generally perpendicular to the transverse frame element  1090  but is not orthogonal to or parallel with the longitudinal axis of the cultivator frame. Thus, longitudinal axis B of the upper shank section  1011  is also not orthogonal to or parallel with the longitudinal axis of the cultivator frame, but is perpendicular to the transverse frame element  1090 . The lower shank section  1013  is thus transversely offset from the longitudinal axis B of the upper shank section  1011 . The longitudinal axis B of the upper shank section  1011  preferably forms an angle in a range of from about 30 degrees to about 60 degrees with the longitudinal axis of the cultivator frame. 
         [0061]    To be able to rotate the shank  1010 , a hydraulic cylinder  1030  pivotally mounted on the transverse frame element  1090  is linked to the middle shank section  1012  of the shank  1010 . The hydraulic cylinder  1030  is pivotally mounted on the transverse frame element  1090  by mounting flange  1031 . A cylinder rod  1034  of the hydraulic cylinder  1030  is pivotally linked to a control arm  1032  by pivot  1033  and the control arm  1032  is pivotally secured to the middle shank section  1012  by a pin  1035  journaled in a sleeve  1036 . As best seen in  FIG. 7A  and  FIG. 7B , extension or retraction of the cylinder rod  1034  causes the control arm  1032  to translate transversely thereby causing the middle shank section  1012  to translate transversely through an arcuate path about the longitudinal axis B of the upper shank section  1011 . The upper shank section  1011  therefore rotates about the longitudinal axis B and, as described in more detail below, the orientation of the coulter wheel  1020  is thereby made to change. The hydraulic cylinder may be powered by a hydraulic fluid pump hydraulically connected to the cylinder by fluid lines. Hydraulic connections for tillage implements are well known in the art. Although a hydraulic cylinder is particularly exemplified, it is evident that any form of actuator may be employed, for example manual actuators such as hand cranks, or other powered actuators such as electric or pneumatic actuators. 
         [0062]    The coulter wheel  1020  has two opposed faces  1023 ,  1025  and an edge  1024 . When the rod  1034  of the hydraulic cylinder  1030  is fully extended as shown in  FIG. 7A ,  FIG. 8A  and  FIG. 9A , the coulter wheel  1020  is in a first orientation whereby the faces  1023 ,  1025  are substantially oriented in a first plane having a first angular relationship to a horizontal plane defined by the longitudinal and transverse frame elements of the cultivator frame and a vertical longitudinal plane perpendicular to the horizontal plane. When the rod  1034  of the hydraulic cylinder  1030  retracts, the control arm  1032  begins to translate transversely. Transverse translation of the control arm  1030  causes the middle shank section  1012  to translate in the same direction, but because the middle shank section  1012  is connected to the upper shank section  1011 , the middle shank section  1012  follows and arcuate path with the upper shank section  1011  rotating about the longitudinal axis B. The pin  1035  rotatatable in the sleeve  1036  to prevent binding as the middle shank section  1012  translates arcuately while the control arm  1032  translates linearly. Rotation of the upper shank section  1011  causes the lower shank section  1013  to move. Because the lower shank section  1013  is transversely offset in relation to the upper shank section  1011  and because the middle shank section  1012  connecting the lower shank section  1013  to the upper shank section  1011  provides for bends that change the angular orientation of the shank  1010  at intervals along the length of the shank  1010 , the simple rotational movement of the upper shank section  1011  around one axis (i.e. the longitudinal axis B) translates into a more complicated movement of the lower shank section  1013  around three orthogonal spatial axes. The movement of the lower shank section  1011  translates to a movement of the coulter wheel  1020  around the three orthogonal spatial axes as well, such that the coulter wheel  1020  comes to occupy a second orientation as shown in  FIG. 7B ,  FIG. 8B  and  FIG. 9B  whereby the faces  1023 ,  1025  are substantially oriented in a second plane having a second angular relationship to the horizontal plane defined by the longitudinal and transverse frame elements of the cultivator frame and the vertical longitudinal plane perpendicular to the horizontal plane. The second orientation of the coulter wheel is angularly different about the three orthogonal spatial axes than the first orientation, thus the coulter wheel  1020  has rotated about three axes instead of one axis. Therefore, the faces  1023 ,  1025  of the coulter wheel  1020  have rotated in both the horizontal and vertical planes. Extension of the cylinder rod  1034  reverses the motions and ultimately returns the coulter wheel  1020  to the first orientation. 
         [0063]    The coulter wheel  1020  is therefore adjustable in two planes and three axes and can engage soil in a various ways depending on the extent of rotation of the upper shank section  1011 , which in turn depends on how far the cylinder rod  1034  retracts. It is evident that with appropriate choice of actuator and appropriate design of how the actuator is coupled to the shank, the upper shank section can be made to rotate through any angle thereby providing great flexibility and variation in the orientation of the coulter wheel. Preferably, the orientation of the coulter wheel is adjustable through a range of angles from about −5 degrees to about 20 degrees with respect to a normal to the horizontal plane and from about −5 degrees to about 20 degrees with respect to the vertical plane. 
         [0064]    Referring to  FIG. 11A ,  FIG. 11B  and  FIG. 11C , the coulter wheel assembly  1000  of  FIG. 6  is shown except the concave coulter wheel is replaced with a waved coulter wheel  1060 , which allows for less aggressive tillage through the range of angles than a concave coulter wheel. The coulter wheel assembly  1000  of  FIG. 11A ,  FIG. 11B  and  FIG. 11C  otherwise functions in the same manner as the coulter wheel assembly of  FIG. 6 .  FIG. 11A ,  FIG. 11B  and  FIG. 11C  further illustrate a range of angle adjustability for the coulter wheel assembly  1000 . Centerline axis CL is a vertical axis in the vertical plane, the centerline axis CL passing through a contact point  1061  where the coulter wheel  1060  contacts the soil.  FIG. 11A  illustrates the coulter wheel  1060  tipped in one horizontal direction away from the vertical plane (and also tipped in one vertical direction away from a normal to the horizontal plane) so that a face of the coulter wheel  1060  forms an angle of about −5 degrees with respect to the vertical plane. As illustrated in  FIG. 11B , rotation of the upper shank  1011  about the longitudinal axis B causes the coulter wheel  1060  to assume a straight-up position in which the face of the coulter wheel  1060  forms an angle of about 0 degrees with respect to the vertical plane and about 0 degrees with respect to a normal to the horizontal plane (i.e. about 90 degrees with respect to the horizontal plane). As illustrated in  FIG. 11C , further rotation of the upper shank  1011  about the longitudinal axis B causes the coulter wheel  1060  to assume a second position where the coulter wheel  1060  is tipped in the other horizontal direction away from the vertical plane (and also tipped in the other vertical direction away from a normal to the horizontal plane) so that the face of the coulter wheel  1060  forms an angle of about 20 degrees with respect to the vertical plane. As is evident, the face of the coulter wheel  1060  can assume any angle with respect to the vertical plane between the first and second positions. This permits sensitive control over how much contact the face of the coulter wheel  1060  has with the soil, thereby controlling the amount of tillage that may be accomplished, which is especially important when the coulter wheel is concave. 
         [0065]    Comparing  FIG. 11A ,  FIG. 11B  and  FIG. 11C , it is apparent that the contact point  1061  on the coulter wheel  1060  does not change position regardless of the angle of the coulter wheel  1060  or the angle of the longitudinal axis B. The longitudinal axis B of the upper shank  1011  meets the contact point  1061  on the coulter wheel  1060  so that when the hydraulic cylinder  1030  rotates the coulter assembly  1000  by rotating the upper shank  1011  the contact point  1061  remains at a constant position. Thus, the coulter wheel  1060  can uniformly rotate whether left or right handed assemblies are used, and spacing or line of cut in the longitudinal direction of the cultivator will remain straight. This permits a range of minimum tillage to maximum tillage action in one tillage apparatus. 
         [0066]    Referring to  FIG. 12 , an enlarged view of an underside of a lower shank section  2013  of a coulter wheel assembly  2000  without a coulter wheel is shown. The coulter wheel assembly  2000  is an embodiment with a reverse handedness to the coulter wheel assembly depicted in  FIG. 6 ,  FIG. 7A ,  FIG. 7B ,  FIG. 8A ,  FIG. 8B ,  FIG. 9A  and  FIG. 9B .  FIG. 12  shows details of one embodiment of a safety mechanism for the coulter wheel assembly, which may be applied to other embodiments of the coulter wheel assembly. Elbow  2015  of the lower shank section  2013  comprises spring steel to provide resilience. The lower shank section  2013  is mounted to a lower shank mount  2016  between a pair of lugs  2009   a ,  2009   b  and a pair of gussets  2018   a ,  2018   b . A resilient block  2043  is provided between the lower shank section  2013  and an upper plate  2017  of the lower shank mount  2016 . The lugs  2009   a ,  2009   b  allow the lower shank section  2013  to pivot around a pair of pivot pins  2006   a ,  2006   b  mounted within resilient bushings  2019   a ,  2019   b , respectively. Pivoting of the lower shank section  2013  about the pivot pins  2006   a ,  2006   b  causes compression of the resilient block  2043 . The resilient elbow  2015 , the resilient block  2043  and to a lesser extent the resilient bushings  2019   a ,  2019   b  absorb load caused by deflection of the coulter wheel assembly  2000  when the coulter wheel assembly  2000  strikes a hard obstacle, thereby mitigating damage to the coulter wheel assembly. 
         [0067]    While a variety of actuators may be employed, the use of powered actuators permits an operator to change coulter wheel orientation on the fly. For example, with a hydraulic cylinder actuator, an operator in a cab of the transportation can set the coulter wheel orientation as desired to match upcoming soil conditions without the need to stop the tillage apparatus. When minimal soil disturbance is desired, the coulter wheel may be oriented vertically straighter. When greater soil disturbance is desired, the face of the coulter wheel may be angled more out of the vertical plane and angled more away from a normal to the horizontal plane. The orientation of the coulter wheels may be customized to meet specific needs. 
         [0068]    Coulter wheel assemblies may be mounted on a transverse frame element in gangs. Each coulter wheel assembly in the gang may be individually controlled, for example each having its own actuator. Individual control of the coulter wheel assemblies permits orienting each coulter wheel differently if desired. If there is no need or desire to provide individually controlled coulter wheel assemblies, two or more of the coulter wheel assemblies may share an actuator so that the two or more assemblies are controllable simultaneously in the same manner. 
         [0069]    In one embodiment referring to  FIG. 5A ,  FIG. 5B  and  FIG. 5C , a gang of three coulter wheel assemblies  100 ,  110 ,  120  are shown mounted on a single transverse frame element  900 . The coulter wheel assemblies  100 ,  110 ,  120  are the same and are the same design as the one depicted in  FIG. 1 . A cylinder rod  334  of a single hydraulic cylinder  300  is pivotally linked to a rotatable arm  102  of the coulter wheel assembly  100  and rotatable arms  102 ,  112 ,  122  of the three coulter wheel assemblies  100 ,  110 ,  120 , respectively, are linked together by a linkage bar  350 . Linear movement of the cylinder rod  334  causes pivoting of the rotatable arm  102 , which in turn causes linear translation of the linkage bar  350 . Linear translation of the linkage bar  350  causes pivoting of the rotatable arms  112 ,  122  by the same amount and in the same direction as the pivoting of the rotatable arm  102 . As previously described, rotation of the rotatable arms  102 ,  112 ,  122  ultimately causes coulter wheels  106 ,  116 ,  126 , respectively, to change orientations. The three coulter wheels in the gang have the same orientation with respect to each other. 
         [0070]    In another embodiment referring to  FIG. 10A ,  FIG. 10B  and  FIG. 100 , a gang of four coulter wheel assemblies  1100 ,  1200 ,  1300 ,  1400  are shown mounted on a single transverse frame element  1900 . The coulter wheel assemblies  1100 ,  1200 ,  1300 ,  1400  are the same and are the same design as the one depicted in  FIG. 6 . A cylinder rod  1334  of a single hydraulic cylinder  1330  is pivotally linked to a single control arm  1332 , which is pivotaly linked to the middle shank sections  1112 ,  1212 ,  1312 ,  1412  of the four coulter wheel assemblies  1100 ,  1200 ,  1300 ,  1400 , respectively. Linear movement of the cylinder rod  1334  linear transverse translation of the control arm  1332 , which in turn causes the middle shank sections  1112 ,  1212 ,  1312 ,  1412  of the four coulter wheel assemblies to translate transversely by the same amount in an arcuate path. As previously described, translation of the middle shank sections  1112 ,  1212 ,  1312 ,  1412  ultimately causes coulter wheels  1106 ,  1206 ,  1306 ,  1406 , respectively, to change orientations. The four coulter wheels in the gang have the same orientation with respect to each other. 
         [0071]    The novel features will become apparent to those of skill in the art upon examination of the description. It should be understood, however, that the scope of the claims should not be limited by the embodiments, but should be given the broadest interpretation consistent with the wording of the claims and the specification as a whole.