Patent Publication Number: US-2018042165-A1

Title: Hardpan Apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. provisional patent application no. 62/374,096, filed Aug. 12, 2016, the entire contents of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to machinery and apparatus for breaking up soil layers in agriculture. In particular, it relates to machinery and apparatus for breaking up the hardpan subsoil layer. 
     BACKGROUND 
     Soil compaction on agricultural land is a growing concern, due to the increasing size and weight of tractors and other farm equipment. Wheel traffic from heavy farm equipment, particularly while the soil is wet, is generally accepted to be the main cause of soil compaction. Over time, soil compaction causes the development of a dense subsoil layer, known as the “hardpan” or the “hardpan layer”. This can reduce the water infiltration and drainage of the soil and impede root growth, resulting in reduced crop yields. Soil compaction at the surface layer can also increase runoff, resulting in increased erosion and water loss. 
     One approach to minimizing the effects of soil compaction is to control field traffic, so as to minimize the amount of compaction that occurs. However, it is not always possible to avoid driving heavy equipment over the soil, during times when the soil is particularly susceptible to compaction, such as when it is wet. Further, once subsoil compaction has occurred, its effects can last for years. Accordingly, techniques for remediating subsoil compaction are required. 
     Traditionally, agricultural land suffering from subsoil compaction is treated using devices known as “rippers” or “deep rippers”, which use large tines that slice through the soil to the desired depth in order to break apart the hardpan. However, the effectiveness of these devices is highly variable. 
     SUMMARY OF THE INVENTION 
     An apparatus for breaking up the hardpan subsoil layer of agricultural land, according to the present invention, has a wheeled frame adapted to connect to a tractor for towing over the agricultural land. A roller having a circular cross-section, a length, a circumferential face, and opposing sidewalls is rotatably mounted within the frame. A plurality of spike members are attached to the circumferential face of the roller and extend outwardly therefrom beneath the frame for penetrating engagement with the hardpan subsoil layer. 
     The roller rotates, in response to the forward motion of the frame, as the apparatus is pulled behind the tractor, causing the spikes to penetrate the soil and the subsoil hardpan layer, thereby breaking up the hardpan. 
     In another embodiment, the plurality of spike members are arranged on the circumferential face of the roller in rows between the sidewalls. 
     In another embodiment, the rows are helical rows. 
     In another embodiment, each spike member is fitted within a collar, which is fixedly attached to the circumferential face, and is attached thereto by means of a shear pin. 
     In another embodiment, each spike member is equidistantly spaced apart from each adjacent spike member in the rows and one or more scraper devices are mounted on the frame and aligned with the equidistant spaces between the spike members. The scraper devices have a scraper blade positioned adjacent the circumferential face and spaced apart therefrom. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the invention may be more clearly understood, a preferred embodiment thereof will now be described in detail by way of example, with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective view of the hardpan apparatus, according to the present invention. 
         FIG. 2  is a side view of the hardpan apparatus. 
         FIG. 3  a side view of the roller of the hardpan apparatus, showing the rows of spikes thereon. 
         FIG. 4  is a detail view of the scraper devices, showing the scraper blades positioned adjacent the roller in the space between adjacent spikes. 
         FIG. 5  is a detail view of the rear end of the frame of the hardpan apparatus, showing the adjustable ride height system. 
         FIG. 6  is a detail view of the parking stand at the front of the frame. 
         FIG. 7  is a side view of the hardpan apparatus, being pulled by a tractor. 
         FIG. 8  is a side view of a spike below the roller, shown penetrating the hardpan subsoil layer. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The hardpan apparatus, according to the present invention, is used to break up compacted soils, for example the hardpan subsoil layer. The apparatus comprises a roller penetrating device, or roller, which is mounted within a wheeled frame, designed to be towed behind a tractor that provides the towing power for the apparatus. The frame is constructed to be open at the bottom to permit engagement of the roller with the ground surface. The wheels on the frame are retractable to thereby fully engage the roller with the ground surface. 
     When the hardpan apparatus is drawn over a field, a plurality of spikes on the roller pierce, disturb, and loosen the soil to allow growing plant roots to grow down into mellow, organic, productive soil. The hardpan apparatus, when drawn over a field, also leaves an organized pattern of penetrated impressions in the soil allowing moisture to move vertically and horizontally through the soil, thereby reducing runoff. 
     As shown in  FIG. 1 , the hardpan apparatus  1  has a wheeled frame  2  and a roller  3 , rotatably mounted within the frame  2 . The frame  2  has a plurality of structural members  4 , a front end  5 , a rear end  6 , and sides  7 . The plurality of structural members  4  are arranged to provide attachment points for the roller  3  and to give rigidity to the frame  2 . On the front end  5  of the frame  2  is a linkage  8  for connecting the frame  2  to a tractor. As is known in the art, any suitable linkage may be used, for example, a drawbar hitch or three-point hitch. As shown in  FIGS. 1, 2, 6, and 7 , a tongue  4   a  extends forwardly from the front end  5  of the frame  2  and may also angle downwardly at its forward-most end to provide an optimum connection point with the tractor. Preferably, the linkage  8  is located at the end of the tongue  4   a.    
     The roller  3  is cylindrical having a circumferential face  9  and opposing sidewalls  10 . As shown in  FIG. 3 , the roller  3  is mounted within the frame  2  by way of axles  11 , between the sides  7  and intermediate the front and rear ends  5  and  6  of the frame  2 . The axles  11  extend outwardly from the centre of the opposing sidewalls  10  and are seated within rotary bearings  12  attached to the sides  7  of the frame  2 . The roller  3  is thereby permitted to rotate freely about its longitudinal axis. Preferably, the roller  3  is hollow with one or more hollow compartments that may be filled with liquid weight ballast, typically water, through an aperture  13  in one of the sidewalls  10 , to add weight as required. Weight ballast, may also be added on a platform (not shown) on top of the frame  2 . Optionally, a brake mechanism (not shown) may be provided to prevent rotation of the roller  3  when the hardpan apparatus  1  is not in use and for safety purposes. 
     A plurality of elongated spike members, or spikes  14 , are mounted on the circumferential face  9  of the roller  3  and extend radially outwardly therefrom and beneath the frame  2  for penetrating engagement with the hardpan subsoil layer. The spikes  14  are attached to the circumferential face  9  by way of shear pins  15  to minimize damage to the hardpan apparatus  1  in the event one of the spikes  14  hits a rock or other debris during operation. In that event, the spike  14  will shear the shear pin  15  at the connection point and detach. At least a portion of each spike  14  may be coloured to assist in locating any detached or broken spikes  14  in the field. The spikes  14  are arranged about the circumferential face  9  of the roller  3  in rows  16 , across the surface of the roller  3 . 
     In the preferred embodiment, there are nine rows  16  of ten spikes  14  arranged about the roller  3 , however, fewer or additional rows  16  of spikes  14  may be used. As shown in  FIGS. 2, 3, and 4 , the spikes  14  in each row  16  are equidistantly spaced apart from each adjacent spike and may be slightly circumferentially offset from one another, thereby providing the roller  3  with helical rows  16  of spikes  14 . For example, each spike  14  may be offset from the adjacent spikes  14  by 1″ along the circumferential face  9  of the roller  3 . This promotes the penetration of the spikes  14  into the soil and more evenly distribute the penetrating forces exerted by the spikes  14  on the ground beneath. This in turn reduces “bumping”, since not all of the spikes  14  in each row  16  engage with the soil simultaneously. Preferably, as the roller  3  rotates, only one spike  14  (at bottom dead-centre) is fully engaged with the soil at any given time and the adjacent spikes  14  in the row  16  are either entering or exiting the soil. 
     The spikes  14  are, preferably, between 16″ and 20″ long. The spikes  14  must be long enough to penetrate the hardpan, which is typically about 8″-9″ below the surface of the soil, as shown in  FIG. 8 . The illustration in  FIG. 8  conceptually shows the hardpan and a spike  14  penetrating therethrough. The hardpan layer generally forms about 1″ below the penetration depth of the tillage instruments used on the soil. Spike length may be selected, based on soil conditions, in particular, the depth of the hardpan layer, as determined, for example, by a survey of the field. 
     As shown in  FIGS. 2-4 , the spikes  14  extend radially outwardly from the circumferential face  9  of the roller  3  and are cylindrical with a generally round cross-section and a wedge-like point  17  at the distal end  18  (the end pointing away from the roller  3 ). The other end, or proximal end  19 , of each spike  14  is fitted within a collar  20  and attached to the collar  20  by way of a shear pin  15 , while the collar  20  is welded to the circumferential face  9  of the roller  3 . 
     The hardpan apparatus may be made vertically adjustable to selectively vary the depth of penetrating engagement of the spikes  14  with the hardpan subsoil layer. As shown in  FIGS. 2 and 5 , two height adjustable wheels  21  are attached at the rear end  6  of the frame  2 . The wheels  21  may be selectively raised and lowered (with reference to the frame) to adjust the ride height of the frame  2  as it is towed behind a tractor. This may be provided, by way of an adjustable ride height system  22 , wherein the wheels  21  are mounted on an axle  23  rotatably supported at one end of a pivoting arm  24 . The other end of the pivoting arm  24  is pivotally attached to the rear end  6  of the frame  2 . A powered actuator, such as a hydraulic piston  25 , is attached to the rear end  6  of the frame  2  and to the pivoting arm  24  to control the angle of the pivoting arm  24  and, thereby, raise and lower the wheels  21 . As the wheels  21  are lowered, the frame  2  is thereby raised, and vice versa. 
     The adjustable ride height system  22  permits the frame  2  to be raised and lowered between a lowered, operative position, and a raised, inoperative position. In the operative position, the wheels  21  are raised and the frame  2  is lowered such that the roller  3  engages the ground and the spikes  14  penetrate the soil, as the hardpan apparatus  1  is pulled behind a tractor. In the inoperative position, the wheels  21  are lowered to make contact with the ground and raise the frame  2  such that the spikes  14  disengage from the ground and remain elevated above and do not make contact therewith. 
     The ability of the spikes  14  to penetrate the soil and subsoil layers depends primarily on the soil conditions and the total weight of the hardpan apparatus  1 . The total weight has three main components: W 1  is the weight of the apparatus itself; W 2  is the weight of the water in the roller  3 , if added, and W 3  is the weight of the weights on top of the frame  2 , if added. The total weight provides a distributed penetrating force F P  on each spike which is engaged with the ground. 
     During operation, the hardpan apparatus  1  is pulled, in the operative position behind a tractor, over soil with a compacted hardpan layer. The spikes  14  penetrate the soil deeply enough to also penetrate the hardpan layer, but the circumferential face  9  of the roller  3  remains at, or just slightly above the surface of the soil. Accordingly, as the tractor pulls the hardpan apparatus  1 , the spikes  14  penetrate the soil, causing the roller  3  to rotate on its rotary bearings  12  within the frame  2 . As the roller  3  rotates, the helical rows  16  of spikes  14  make sequential contact with the soil. The spikes  14 , continue to rotate and move downwardly through the soil until they reach the hardpan. At this point the spikes  14  will penetrate the hardpan at a downward and forward angle, toward the front end  5  of the frame  2 . As the roller  3  continues to rotate, the spikes  14  move through an arc to a downward and rearward angle, toward the rear end  6  of the frame  2 . This results in a disruption, or breaking up, of the hardpan layer. 
     An accessory agricultural implement may be mounted on a rearward extension behind the frame  2  for tandem towing. For example, a harrow rake, may be dragged behind the frame  2  to level and smooth the soil, following disruption of the hardpan. Preferably, two structural members  4  extend rearwardly from the frame  2  with a plurality of chains, or cables, attached therealong. The chains are attached, at one end, to one of the two structural members  4  and at their other end to the harrow rake. The length of the chains is selected to permit the harrow rake to drag along the ground when the frame  2  is in the operative position and to remain elevated above the ground when the frame  2  is in the inoperative position. One or more chains may also be attached at one end to the front end of the harrow rake, and at the other end to the rear end  6  of the frame  2 . 
     As shown in  FIG. 4 , scraper devices, or scrapers  29 , may be mounted on the frame  2  and positioned between the spikes  14  in each row  16 . The scrapers  29  have a scraper blade  30  positioned adjacent the circumferential face  9  of the roller  3  to promote detachment of dirt and debris. The scraper blade  30  is attached to a scraper arm  31  extending from the frame  2  near the rear end  6  thereof. A brace  32  may be attached to the scraper arm  31  near the scraper blade  30  to provide structural support to the scraper arm  31 . The scrapers  29  thereby remove dirt and debris from the circumferential face  9  of the roller  3 , during operation, which could otherwise build up and prevent the spikes  14  from fully penetrating the soil. 
     A parking stand  33  may be attached on the front end  5  of the frame  2  to support the weight of the hardpan device  1  and prevent it from tipping forward when not in use. Preferably, the parking stand  33  is located adjacent to the linkage  8  and is hydraulically raised and lowered. The parking stand  33  may also assist in positioning the linkage  8  at the appropriate height to facilitate connection and disconnection with the tractor. 
     The forgoing description, together with the accompanying figures, set out detail of the structure and function of the present invention, however, the disclosure is to be understood as illustrative of the preferred embodiments and changes may be made without departing from the scope of the invention herein described.