Abstract:
A cultivator apparatus includes a frame, a tube supported on the frame, and a plurality of cultivator rings loosely placed over the axis of said tube. The cultivator rings each include a tubular base including cylindrical interior and exterior circumferential surfaces, and a planer, ring-shaped blade presenting a circular interior circumferential edge and an opposed exterior circumferential edge. The interior edge of each blade is of a diameter slightly larger than the diameter of the exterior surface of the respective base, and each blade is welded to the exterior surface of the respective base along the interior edge. A method of constructing the rings is also provided.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    The present application is a continuation-in-part of U.S. Ser. No. 08/798,565, filed Feb. 11, 1997, by Kevin McDonald, and entitled CULTIVATOR. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    This invention relates to a crop cultivator. More particularly, the invention relates to an enhanced profile cultivator ring for use with a ring-type cultivator.  
           [0003]    Agricultural ring-type cultivators are utilized for a variety of field cultivation tasks including tilling, packing in seeds, sealing in fertilizers and fumigants, breaking clods and crusts in fields, and pulverizing crusted soil. They are typically constructed as a tube or pipe mounted in a frame. A plurality of rings loosely mounted around the tube are used to perform the cultivation tasks. The tube and frame are configured such that the axis of the tube is transverse to the travel of the cultivator when in use. The frame is typically configured so as to constrain each end of the tube at the axis of the tube and to form a yoke for attachment to a tractor or the like for pulling the cultivator over the area to be worked. Existing cultivators may utilize multiple tubes, various configurations of folding attachments, road wheels and hydraulics for moving the cultivator from field to field and similar devices, however, the basic configuration of a tube and frame is common to the various cultivators.  
           [0004]    The rings for contacting the soil to perform the cultivation tasks are loosely mounted around the tube and along the axis thereof The rings are placed side-by-side and sufficiently close that they are constrained so that the plane of the ring is held generally in a vertical orientation and the periphery of the rings are oriented to roll along the field when the cultivator is in use. The interior diameter of the ring typically is one to six inches larger than the outer diameter of the tube. This allows the ring to rotate around the tube as the tube is pulled across the field to be cultivated. Further, the difference between the outer diameter of the tube and the inner diameter of each ring allows that the rings may droop or flex below the tube and, thus, follow the contour of the soil.  
           [0005]    The peripheries of the rings are the portions of the cultivator which contact the soil and perform the cultivation task. Prior art rings are constructed with a series of spikes around the periphery of the ring to perform the cultivation tasks. These spikes act to contact and penetrate the soil as the cultivator passes over the field. The spikes are affixed to the outside of the cultivator ring in a generally radial direction, and may be tipped slightly in a tangential direction in the plane of the ring. The spikes are typically one-half inch to two inches long with an elongated cone or tooth shape and a blunted end. The teeth are spaced nominally two to four inches apart around the circumference of the ring. Prior art rings are typically two to three inches wide in an axial direction of the tube so that, as mounted on the tube, the spacing between the teeth on adjacent rings is two to three inches.  
           [0006]    Existing cultivator ring tooth configurations produce high rolling resistance as the teeth penetrate and embed in the soil when the cultivator passes through the field, increasing the power necessary to pull the cultivator. The length of the teeth on the rings in the prior art configuration is limited, which in turn limits the depth to which prior art cultivators may penetrate the soil to cut through and break up clods and hardpan below the surface of the field. Related to this, it is important that the weight distribution of the penetrating surface of the ring facilitate penetration into the soil. It is desirable for cultivators to push crop stubble and debris below the surface of the field or to lift it and the soil for mixing to facilitate faster breakdown of the plant matter. The spiked configuration has a tendency to only partially push stubble below the surface of the field and its ability to lift soil is limited by the length and configuration of the spikes. Ring breakage due to various stresses placed upon rings in use requires maintenance and creates down-time for ring replacement and, therefore, enhanced ring strength and durability is desirable.  
         BRIEF SUMMARY OF THE INVENTION  
         [0007]    It is an object of the present invention is to provide a cultivator ring configured to provide less pulling resistance than prior art cultivator rings.  
           [0008]    Another object of the invention is to provide a cultivator ring with enhanced down force or penetration relative to conventional rings to facilitate cutting through clods and hardpan below the surface of the field. In addition, it is an object to provide such a ring that has good soil lifting action for churning the soil and covering crop residue.  
           [0009]    A further object of the invention is to provide a ring configuration of enhanced strength and durability to minimize ring breakage.  
           [0010]    In accordance with these and other objects evident from the following description of a preferred embodiment of the invention, a cultivator apparatus is provided with includes a frame, a tube supported on the frame, and a plurality of cultivator rings loosely placed over the axis of said tube. The cultivator rings each include a tubular base presenting cylindrical interior and exterior circumferential surfaces, and a planer, ring-shaped blade having a circular interior circumferential edge and an opposed exterior circumferential edge. The interior edge of each blade is of a diameter slightly larger than the diameter of the exterior surface of the respective base, and each blade is welded to the exterior surface of the respective base along the interior edge.  
           [0011]    By providing a construction in accordance with the present invention, numerous advantages are realized. For example, by employing a tubular base and a planer blade, it is possible to form the rings out of readily available stock material, reducing the cost of manufacture of the rings. In addition, by welding planer blades to a tubular base, the strength of the rings compares favorably to conventional cast rings, and provides enhanced strength and durability, minimizing ring breakage.  
           [0012]    In addition, by providing the blades of the rings with circumferential edges that are star-shaped, presenting an aggressive attack angle to the ground, the rings provide enhanced down force relative to conventional cultivator rings and improve lifting and mixing of the soil with crop debris. As such, it is possible to reduce the number of passes that must be made through the field with cultivating equipment in order to prepare the field for a subsequent planting. Further, deep tillage points may be mounted on the cultivator to improve the deep tillage capabilities of the implement, again reducing the number of passes through the field that are required to prepare it for planting. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
       [0013]    The preferred embodiment of the present invention is described in detail below with reference to the attached drawing figures, wherein:  
         [0014]    [0014]FIG. 1 is a perspective view of a ring-type cultivator upon which are mounted cultivator rings constructed in accordance with a first embodiment of the present invention;  
         [0015]    [0015]FIG. 2 is a partial front elevational view of a cultivator showing a plurality of cultivator rings of the first embodiment;  
         [0016]    [0016]FIG. 3 is an enlarged front elevational view of a cultivator ring constructed in accordance with the first embodiment, partially cut away to illustrate a base and a blade forming a part thereof;  
         [0017]    [0017]FIG. 4 is a vertical cross-sectional view taken along line  4 - 4  of FIG. 2, illustrating the manner in which the cultivator rings are supported on the cultivator;  
         [0018]    [0018]FIG. 5 is a perspective view of a ring-type cultivator upon which are mounted cultivator rings constructed in accordance with a second embodiment of the present invention;  
         [0019]    [0019]FIG. 6 is a fragmentary side elevational view of the cultivator shown in FIG. 5;  
         [0020]    [0020]FIG. 7 is a fragmentary side sectional view of the cultivator shown in FIG. 5, illustrating the manner in which the cultivator rings are supported on the cultivator;  
         [0021]    [0021]FIG. 8 is a fragmentary rear end elevational view of the cultivator shown in FIG. 5, illustrating a plurality of cultivator rings arranged on the cultivator; and  
         [0022]    [0022]FIG. 9 is a fragmentary side elevational view of an earth penetrating point of the blade, shown in FIG. 5. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0023]    Referring initially to FIG. 4, a cultivator ring constructed in accordance with a first embodiment of the present invention is designated generally by the numeral  10 . Cultivator ring  10  comprises a hollow cylindrical-shaped base  12  to the exterior of which is affixed an annular-shaped blade  14 . The exterior edge of the blade  14  has a plurality of notches designated by the numeral  16 .  
         [0024]    Referring now to FIGS. 2 and 4, the cultivator ring  10  in use mounts loosely over a tube  18 . As can best be seen in FIG. 4, the interior dimension of the base  12  of the cultivator ring  10  is appreciably larger than the exterior dimension of the tube  18 , a dimension which is commonly referred to as flex and is designated by the letter A in FIG. 4.  
         [0025]    Turning now to FIGS. 1 and 2, the tube  18  is mounted in a frame  20  and affixed in that frame. The particular shape of the frame  20  or manner and attachment of the frame  20  to the tube  18  is not critical. Various configurations of tubes and frames are suitable for use with the cultivator rings  10  of the present invention. The cultivator rings  10 , tube  18 , and frame  20  form a cultivator  24 .  
         [0026]    The base  12  of cultivator ring  10  preferably has an interior diameter from about eight inches to about eighteen inches and a width along the axis of the cylinder of from about ¼ inches to about five inches. More preferably, ring  10 &#39;s inner diameter is from about ten to about sixteen inches and a width of from about three to about five inches. The thickness of the base  12 , i.e., the difference between the interior diameter and the exterior diameter, is preferably about ⅜ to ½ of an inch, although it would be obvious to one skilled in the art that a greater or lesser dimension would be suitable if consistent with the strength characteristics required to maintain the shape of the cultivator ring in use. The base  14  may be manufactured from plate steel which is rolled into a hollow cylindrical shape and welded or preferably may be made from sections of pipe which is commercially available and sliced perpendicular to the axis thereof in order to produce the short cylindrical shapes required.  
         [0027]    The blade  14  of the cultivator ring  10  is an annular-shaped segment preferably fabricated from ⅜ inch flat plate. The interior diameter of the blade preferably is sized to fit over the applicable base  12  with sufficient gap between the inner diameter of the blade  14  and exterior diameter of the base  12  to allow for irregularities in the two dimensions and provide for a snug fit between the blade  14  and the base  12 . Typically, this gap will be 5 to 10 thousandths of an inch to allow ease of assembly of the base  12  and blade  14 . Preferably, the blade  14  is affixed to the base  12  by means of welding or the like, designated by the number  22  in FIGS. 3 and 4. Preferably, the weld  22  is applied as a fillet weld to both sides of the blade  14  and applied in a skip fashion so as to allow some flex between the blade  14  and the base  12 . The weld may also be applied in a continuous fashion around the entire periphery of the junction of the blade  14  and base  12 . As seen in FIG. 3, the blade  14  is preferably affixed to the center of the base  12  equidistant between the ends of the cylinder forming the base  12  so as to minimize twisting of the cultivator ring  10  in use.  
         [0028]    The radial thickness of blade  14 , shown as dimension B in FIG. 4, preferably is from about two to about eight inches and, more preferably, from about two and one half to about eight inches. As best seen in FIG. 4, blade  14  has a plurality of notches  16  which are generally semicircular in shape and evenly spaced around the outer edge of the blade  14 . Preferably, the notches are spaced at nominally 45 degrees apart around the circumference of the blade  14 , although spacing from about 30 to about 60 degrees apart is acceptable depending upon the particular type of application which is desired for the blade. The notches  16  applied to blade  14  are preferably formed as semicircular notches with a radius of from about one to about four inches, more preferably, from about one and one quarter to about two and one half inches. As will be obvious to one skilled in the art, a variety of other shapes of notches are suitable to application in the present invention.  
         [0029]    In use, a plurality of cultivator rings  10  are loosely fit over a tube  18  which is operably affixed in a frame  20 . As the frame  20  is pulled by a tractor or the like (not shown) over a field of ground for cultivation, the blades  14  engage the soil of the field. FIG. 2 shows a portion of a cultivator  24  in contact with the irregular surface of a field. As is shown in FIGS. 2 and 4, the cultivator rings “float” on the inner tube  18  so as to allow the individual cultivator rings to engage the soil at various heights across the width of the cultivator  24 .  
         [0030]    The cultivator ring  10  of the present invention provides for several advantages over the standard prior art rings. The annular blade shape  14  of the present invention enhances the strength and stability of the ring  10  as compared to a prior art cultivator rings which utilizes pins to penetrate the soil because the blade  14  and base  12  form a “T” shape with inherently rigid characteristics, as best seen in FIG. 3. Thus, the shape of the blade helps provide greater resistance to breakage than presently available rings. Because the cultivator ring  10  is more stable, the blade  14  can be made deeper for greater penetration of the soil to cut through clods and the like above and below the surface of the soil. This allows for more effective pulverization of the soil as the cultivator  24  is pulled over the soil. The deeper blade  14  pushes stubble below the surface of the soil more effectively than pins, in part because the blade  14  edge presents a continuous running surface to the soil as compared to pins which present a discontinuous poking action on a relatively small percentage of the soil. Therefore, the present invention cultivator rings  10  push stubble below the surface more effectively, enhancing rapid breakdown of the stubble.  
         [0031]    The notches  16  in the blade  14  help provide a positive surface on which the cultivator ring can bite into the soil, enhancing rotation of the cultivator ring through the soil. The notches  16  also reduce the surface area of the blade  14  against the soil, increasing relative pressure of the blade  14  against the soil for easier penetration. The relatively smooth profile presented by the smooth  20  annular shape of the blade as compared to prior art pins provides less resistance against the blade as the cultivator roller is being pulled through the soil.  
         [0032]    The continuous edge presented by the blade  14  of the present invention to the soil allows a wider spacing between blades to be utilized to effectively cover the same amount of soil as compared to a prior art pin device. Wider spacing between the blades  14  further decreases resistance to pulling the cultivator roller through the soil, further increasing the relative pressure of the blade  14  edge against the soil, enhancing penetration.  
         [0033]    One skilled in the art would appreciate that various types of materials may be employed for the blades  14  and base  12  of the present invention. The particular material utilized will determine the mass, rigidity, and life of the cultivator ring  10 . In most instances, it is preferable to use common plow-grade steel, such as Standard of Automotive Engineers grade 1080 or harder for the blade  14  and standard pipe-grade steel such as grade A36 steel or harder for the base  12 , welded together with a compatible welding material. Alternately, a material such as AR400 steel could be used to form the blade and base. As would be obvious to one skilled in the art, various other materials will provide acceptable results.  
         [0034]    Turning to FIG. 5, a second cultivator  30  is illustrated, wherein a plurality of rings  32  constructed in accordance with a second embodiment of the invention are employed. The cultivator resembles the cultivator  24  shown in FIGS.  1 - 4 , in that it is adapted to be pulled behind any suitable towing implement such as a tractor or the like. However, the cultivator  30  differs from the cultivator  24  in several respects.  
         [0035]    The cultivator  30  broadly includes a frame  34 , a plurality of the cultivator rings  32  supported on the frame for rotation as the towing vehicle pulls the cultivator through a field, and a cleaning assembly  36  for cleaning the spaces between the rings during cultivation so that debris does not build up between the rings.  
         [0036]    The frame  34  includes a front portion  38  that is hitched to the towing vehicle, and a rear portion  40  that is supported by the front portion for pivotal movement between raised and lowered positions. The front portion  38  includes a rear tool bar  42 , a pair of laterally disposed side bars  44  connected to the rear tool bar at the ends thereof, and a pair of front bars  46  connected to the side bars and to one another at the front of the frame. A hitch is secured to the front frame portion, and consists of a single-point, three-point, or any other type of hitch desired.  
         [0037]    The rear portion  40  of the frame includes a horizontal frame member  48 , a pair of laterally disposed side arms  50  connected to the horizontal frame member at the ends thereof, and a tube  52  connected between the side arms and extending in a direction parallel to the horizontal frame member  48 . As shown in FIG. 6, the horizontal frame member  48  is supported on the tool bar  42  of the front portion of the frame by a pair of support assemblies  53 , each of which includes a support bracket  54  secured to the tool bar, a support arm  56  mounted on the bracket for pivotal movement between raised and lowered positions, and a hydraulic piston and cylinder assembly  58  that is connected between the bracket and support arm for shifting the support arm. Alternately, a threaded adjustment mechanism of conventional construction could be employed between the horizontal frame member  48  and the tool bar  42  to provide the pivotal movement.  
         [0038]    As illustrated in FIG. 1, each support bracket  54  includes a pair of laterally spaced bracket elements that are rigidly secured to the tool bar  42  and that present an interior space within which the support arm is received. Returning to FIG. 6, a pin  60  is supported between the bracket elements, and the support arm  56  is received on the pin for pivotal movement between the raised and lowered positions. The support arms  56  are rigidly connected to the horizontal frame member  48  so that the arms pivot together to move the rear frame portion up and down about the pins  60  when the piston and cylinder assemblies  58  are actuated. Preferably, control of the assemblies is achieved by conventional hydraulic circuitry which includes a control valve that may be actuated from the cab or seat of the towing vehicle to extend and retract the pistons of the assemblies, as desired.  
         [0039]    The side arms  50  of the rear frame portion are each V-shaped, presenting a pair of arm segments protruding outward from the horizontal frame member. As shown in FIG. 1, the tube  52  is connected between the lower segments of the side arms, and the cleaning assembly  36  is supported between the upper segments. The tube  52  is circular in cross section, as illustrated in FIG. 7, and is preferably formed of a rigid supportive material such as steel or other metal. A pair of end plates  62 , shown in FIG. 6, are provided for closing off the ends of the tube and for providing a mounting surface by which the tube is secured to the side arms of the frame by threaded fasteners or the like. As such, the tube does not rotate relative to the frame. The tube  52  includes an outer surface of a predetermined diameter that is substantially smaller than the inner diameter defined by the cultivator.  
         [0040]    The cultivator ring  32  constructed in accordance with the second embodiment of the invention each broadly include a base  64  and a blade  66  welded to the base. As shown in FIG. 7, the base  64  of each cultivator ring preferably has an interior diameter from about eight inches to about eighteen inches and, as shown in FIG. 8, includes a width along the axis of the tube of from about two inches to about five inches. More preferably, the ring inner diameter is from about ten to about sixteen inches and the ring includes a width of from about three to about five inches. The radial thickness of the base  64  is preferably about ⅜ to ½ of an inch, although it would be obvious to one skilled in the art that a greater or lesser dimension would be suitable if consistent with the strength characteristics required to maintain the shape of the cultivator ring in use. The base  64  may be manufactured from plate steel which is rolled into a hollow cylindrical shape and welded. Preferably, however, it is made from conventional pipe of a hard steel by cross cutting circular sections of pipe in a plane perpendicular to the longitudinal axis thereof in order to produce the short tubular shapes required.  
         [0041]    Returning to FIG. 7, the blade  66  of the cultivator ring is an annular-shaped segment that is preferably fabricated from a flat plate having a thickness of ⅜ inches. An interior hole is cut or punched into the plate, and presents a diameter slightly larger than the outer diameter of the base  64  such that the blade can be positioned on the base during manufacture with a sufficient gap between the inner diameter of the blade and exterior diameter of the base to allow for irregularities in the two dimensions and provide for a snug fit between the blade and the base. Alternately, the blade can be formed by two flat plate sections that are welded together during manufacture. Typically, this gap will be 5 to 10 thousandths of an inch to allow ease of assembly of the base and blade Preferably, the blade  66  is affixed to the base by means of welding or the like, and the weld is applied as a fillet weld to both sides of the blade and in a skip fashion so as to allow some flex between the blade and the base. Alternately, the weld may be applied in a continuous fashion around the entire periphery of the junction of the blade and base. This alternate construction reduces the waste of material relative to a construction in which the blade is formed from a single flat plate of material. As shown in FIG. 8, the blade  66  is preferably affixed to the center of the base equidistant between the axial ends or edges of the cylinder forming the base so as to minimize twisting of the cultivator ring in use.  
         [0042]    The radial dimension of the blade  66  preferably is from about two to about eight inches and, more preferably, from about two-and-one-half to about eight inches. In accordance with the second embodiment of the invention, the outer edge of the blade is cut or otherwise shaped to present a plurality of earth-penetrating points  68 . As shown in FIG. 9, each point includes a leading edge  70 , a trailing edge  72 , and a tip  74  that separates the edges from one another. The angle formed between the leading edge of each point and a radial line  76  extending through the tip is smaller than the angle formed between the same radial line and the trailing edge of the point. As such, the leading edges  70  of the points  68  present an aggressive angle of attack that enhances soil penetration relative to conventional cultivator rings, and the trailing edges  72  of the points provide improved lifting of soil as the rings rotate up out of the ground to facilitate mixing of the soil with crop stubble resting on the surface of the ground. The trailing edges  72  of the points also help to drive the ring to reduce the amount of soil that is pushed forward during operation.  
         [0043]    Because the cultivator rings  32  of the second embodiment provide increased soil lifting relative to the first embodiment, it is necessary in using the second embodiment to employ the cleaning assembly  36  to prevent soil and debris from getting clogged between adjacent cultivator ring blades. As shown in FIG. 5, the cleaning assembly broadly includes a support bar  78  supported between the side arms  50  of the rear frame portion  40 , and a plurality of shoe assemblies  80  depending from the support bar. As shown in FIG. 8, the support bar  78  includes a plurality of laterally spaced support rings that are secured to the bar along the width thereof, each presenting a vertical hole within which one of the shoe assemblies  80  is received. As shown in FIG. 7, each shoe assembly  80  includes an arm  82  received in one of the support rings, and a shoe  84  that is attached to the lower end of the arm. Preferably, a set screw or the like is provided in association with each support ring for securing the respective support arm at a fixed position relative to the underlying cultivator rings, and the set screw permits this position to be adjusted, as desired.  
         [0044]    The shoe  84  of each assembly includes a proximal end received on the support arm  82  of the assembly, and a distal end that protrudes downward and inward toward the outer surface of the bases of a pair of laterally adjacent cultivator rings of the apparatus. The shoes are disposed between the blades of adjacent rings  32 , and function during rotation of the rings to clean the spaces between the blades to improve penetration of the rings into the soil.  
         [0045]    With reference to FIG. 1, the plurality of cultivator rings  32  are loosely fit over the tube  52 , and the tube is affixed to the side arms  50  of the rear frame portion  40  in the manner described above to secure the rings on the apparatus. Thereafter, when the rear frame portion of the frame is lowered to the ground and the apparatus is towed across a field to be cultivated, the blades  66  penetrate the soil of the field. As with the rings of the first embodiment, the rings  32  of the second embodiment are allowed to float on the tube so as to allow the individual cultivator rings to engage the soil at various heights across the width of the cultivator, accommodating varying ground heights across the width of the apparatus. However, because of the unique earth-penetrating points  66  on the rings, the blades  66  penetrate the soil, breaking up large clods and stubble, and lifting the soil and stubble for better mixing. In addition, the blades  66  move soil in a way to resettle and level the seed bed, and reduces compaction of the soil.  
         [0046]    If desired, the rear portion of the frame may be lifted from engagement with the ground by actuating the piston and cylinder assemblies  58 , raising the cultivator rings from the ground on the fly. This type of mounting arrangement is particularly useful where the front portion  38  of the frame is fitted with deep tillage points  86  or other tillage implements that are adapted for use either in combination with the cultivator rings or independently thereof However, the arrangement also facilitates turning of the apparatus between rows and transport of the apparatus between fields.  
         [0047]    The cultivator ring of the present invention provides for several advantages over the standard prior art rings. The annular blade shape of the present invention enhances the strength and stability of the ring as compared to a prior art cultivator rings which utilizes pins to penetrate the soil because the blade and base form a “T” shape with inherently rigid characteristics, as best seen in FIG. 8. Thus, the shape of the blade helps provide greater resistance to breakage than presently available rings. Because the cultivator ring is more stable, the blade can be made deeper for greater penetration of the soil to cut through clods and the like above and below the surface of the soil. This allows for more effective pulverization of the soil as the cultivator is pulled over the soil. The deeper blade penetrates the surface of the soil more effectively than the thicker pins of conventional constructions.  
         [0048]    One skilled in the art would appreciate that various types of materials may be employed for the blades and base of the present invention. The particular material utilized will determine the mass, rigidity, and life of the cultivator ring In most instances, it is preferable to use common plow-grade steel, such as Standard of Automotive Engineers grade 1080 or harder material, such as AR400 steel, for the blade and standard pipe-grade steel such as grade A36 steel, or harder material, for the base, welded together with a compatible welding material. As would be obvious to one skilled in the art, various other materials will provide acceptable results.  
         [0049]    From the foregoing it will be seen that this invention is one well-adapted to attain all the ends and objects set forth above, together with other advantages which are obvious and which are inherent in the structure.  
         [0050]    It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.  
         [0051]    Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.