Abstract:
A method of soil preparation simultaneously ploughs soil and tills soil ploughed in a previous pass. An apparatus for tilling soil provides tilling members mounted for deployment on either side of a tractor. The tilling members on one side of the tractor may be brought into engagement with the soil while tilling members on the other side of the tractor are lifted away from the soil. The tilling members are located to coincide with an adjacent strip of land ploughed in a previous pass of the tractor.

Description:
TECHNICAL FIELD 
       [0001]    This invention relates to agriculture. In particular, the invention relates to tilling soil in preparation for planting crops. 
       BACKGROUND 
       [0002]    Preparing a field for planting crops involves a number of steps. Typically, the field is first ploughed. Ploughing turns a top layer of soil over. Plants growing in the top layer of soil are under the top layer after ploughing. This plant matter can decay to build the soil and provide nutrition for the current-year&#39;s crop. This plant matter is known as ‘green fertilizer’. 
         [0003]    One or more additional preparation steps are typically performed after ploughing to break up the soil. Breaking up the soil makes it easier for a new crop to establish itself and to access nutrients in the soil and also facilitates planting. A harrow is a tool commonly used for this purpose. One type of harrow is a disc harrow. The disc harrow has a number of rows of disc-like blades that cut the soil as they pass through it. After ploughing a farmer may pull a disc harrow (or other harrow) over the ploughed field to break up the soil sufficiently to allow a new crop to be planted. 
         [0004]    Soil compaction resulting from driving repeatedly over the field with heavy equipment can harm the land. Repeated passage of tractors or other equipment can seal off the natural passages by way of which air and water can penetrate the soil. 
         [0005]    The field of agriculture is becoming increasingly competitive. Farmers work hard to reduce their cost of production. Field preparation involves significant costs because it typically involves traveling over every part of the field to be prepared multiple times. This results in very significant costs for fuel as well as wear and tear on expensive tractors. Labour costs can also be significant. 
         [0006]    Over the years farmers have taken advantage of a number of developments that help to reduce costs of production. One of these developments is the tumble plough. Because ploughs are “handed” a farmer cannot simply plough a furrow to one end of the field and then turn around and plough another furrow adjoining the just-ploughed area. This would result in the soil being turned over in one direction for the first furrow (or set of furrows in the case of a multi-bottom plough) and turned over in the opposing direction on the return trip. 
         [0007]    A tumble plough has two sets of plough shares. The two sets are oppositely handed (one set turns the soil over to the right-hand side of the tractor as the tractor pulls the plough ahead and the other set turns the soil over to the left-hand side of the tractor as the tractor moves ahead). Using a tumble plough, a farmer can plough a set of furrows along a field in one direction. When the farmer reaches the end of the field, the farmer can lift the plough shares clear of the ground, flip the plough over to bring the second set of plough shares into operating position, turn around in a U-turn, drop the plough into engagement with the ground and plough another set of furrows immediately next to the just-ploughed area. This significantly increases efficiency and can save both fuel and labour costs in ploughing the field (at the cost of the capital investment in a tumble plough). 
         [0008]    There remains a need for methods and apparatus useful in soil tilling which provide further savings in time and/or fuel. 
       SUMMARY 
       [0009]    The following embodiments and aspects thereof are described and illustrated in a way that is meant to be exemplary and illustrative, not limiting in scope. The invention has a number of aspects. These include novel agricultural soil tilling implements; tractors equipped with soil tilling implements; and methods for tilling soil. 
         [0010]    One aspect of the invention provides a method for preparing soil. The method comprises: with a tractor, pulling a plough to plough a first strip of ploughed land; driving the tractor adjacent to the first strip pulling the plough to plough a second strip of ploughed land contiguous with the first strip; and, while ploughing the second strip, tilling the first strip with a first tiling member mounted to the tractor and projecting to a first side of the tractor. 
         [0011]    Another aspect of the invention provides soil tilling apparatus comprising: a member bearing tilling members that is mounted to a tractor and is movable between a lowered configuration in which the tilling members engage the soil across a strip of soil offset to one side of the tractor and a raised configuration wherein the tilling members are lifted away from the soil and an actuator coupled to move the member between its lowered and raised configurations. 
         [0012]    Another aspect of the invention provides an agricultural implement comprising: a hitch configured for coupling the agricultural implement to a tractor; a frame supported by the hitch; first and second arms pivotally mounted to the frame; tilling members mounted to the first and second arms. The first and second arms are each pivotally movable between raised and lowered configurations. When the first arm is in its lowered configuration, the corresponding tilling members are positioned to engage the ground in a first strip that is offset to a first side of the tractor. When the second arm is in its lowered configuration, the corresponding tilling members are positioned to engage the ground in a second strip that is offset to a second side of the tractor opposed to the first side. The first and second strips are spaced apart from one another by a third strip. The implement may be mounted to a tractor in combination with a plough with the plough dimensioned such that a strip ploughed by the plough lies substantially within the third strip. 
         [0013]    Further aspects of the invention and features of example embodiments of the invention are described below and illustrated in the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0014]    The accompanying drawings show non-limiting example embodiments of the invention. 
           [0015]      FIG. 1  is a top-view of a tractor pulling a tumble plough. 
           [0016]      FIGS. 2A to 2C  are top-views of a tractor ploughing a field according to a method the invention. 
           [0017]      FIG. 3  is a perspective view of an implement according to an example embodiment. 
           [0018]      FIG. 4  is a front elevation view of the implement of  FIG. 3 . 
           [0019]      FIG. 5  is a top plan view of the implement of  FIG. 3 . 
           [0020]      FIG. 6  is a perspective view of the implement of  FIG. 3  in an operating mode with one arm raised. 
           [0021]      FIG. 7  is a front elevation view of the implement of  FIG. 3  in an operating mode with one arm raised. 
           [0022]      FIG. 8  is a perspective view of the implement of  FIG. 3  in a transport configuration with both arms raised. 
           [0023]      FIG. 9  is a front elevation view of the implement of  FIG. 3  in a transport configuration with both arms raised. 
           [0024]      FIGS. 10A ,  10 B and  10 C are top plan views showing the end of one arm of the implement of  FIG. 3  and illustrating how an angle of a soil tilling member may be adjusted. 
           [0025]      FIG. 11  is a front elevation view of an implement according to an alternative example embodiment. 
       
    
    
     DESCRIPTION 
       [0026]    Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense. 
         [0027]    Embodiments of this invention provide a front-mounted tilling assembly that may be used in conjunction with a plough. The tilling assembly can be controlled to till the soil that was ploughed on a previous pass of the tractor. The tilling assembly can be used most effectively in combination with a tumble plough. 
         [0028]      FIG. 1  is a top-view of a tractor  10  pulling a tumble plough  12 . A tilling apparatus  15  is mounted on the front of the tractor  10 . Tilling apparatus  15  comprises arms  16 R and  16 L arranged to project respectively on the right and left-hand sides of tilling apparatus  15 . Arms  16 R and  16 L each comprise tilling members. In the illustrated embodiment, the tilling members comprise disc blades  18 . The tilling members may optionally comprise other blades or tines in addition to or in the alternative to disc blades. Disc blades  18  are mounted to shafts  19  (see  FIG. 5 ) which are rotatably mounted to the corresponding arm  16 R or  16 L. Arms  16 R and  16 L can be lowered so that the corresponding disc blades  18  are in contact with and till the soil or raised so that the arm  16 R or  16 L is not in contact with the soil. 
         [0029]      FIG. 2A  is a top-view of a tractor  10  commencing to plough a field. The tractor will follow path  20  to allow plough  12  to cover the entire area of the field. In  FIG. 2A , the tractor has commenced ploughing. The plough shares on plough  12  are turning over the soil towards the right-hand side of the tractor as indicated by arrows  22 . Arms  16 R and  16 L are in their raised positions with disc blades  18  out of contact with the ground. The weight of arms  16 R and  16 L on the front end of tractor  10  provides front ballast that assists in maintaining traction (in the event that tractor  10  has driven front wheels  11 ). 
         [0030]    In  FIG. 2B , tractor  10  has completed its first pass along the field and has turned around, flipped tumble plough  12  and started to proceed in the opposite direction. It can be seen that the tumble plough  12  is now ploughing so that soil is turned over toward the left-hand side of tractor  10  as indicated by arrows  24 . Arm  16 L has been lowered so that its tilling members (disc blades  18 ) are tilling the soil that was ploughed on the previous pass. Arm  16 R remains in its raised position. 
         [0031]      FIG. 2C  shows the field with the tractor on the next pass. The tumble plough  12  has been flipped again and is now ploughing so that soil is turned over towards the right-hand side of tractor  10 . Arm  16 R has been lowered to bring the corresponding tilling members (e.g. disc blades  18 ) into engagement with the ground ploughed on the previous pass. Arm  16 L has been raised. The tilling members (disc blades  18 ) on the lowered arm  16 R are tilling the soil turned over in the previous pass of plough  12 . 
         [0032]    By proceeding as described above, a farmer can both plough and till a field with a single pass over the field. Furthermore, since the tilling apparatus may comprise or be used in conjunction with a tumble plow, tractor  10  does not need to travel for any significant distances to transport plough  12  to a new starting point. Tractor  10  can cover the entire field by making U-turns to change direction when it reaches the ends of the field. 
         [0033]    As illustrated in  FIGS. 2B and 2C , the lengths of arms  16  and the portions of those arms which carry tilling members  18  are selected to facilitate tilling of the soil that has been turned over in an adjacent previous pass of plough  12 . The portion  25  (see  FIG. 4 ) of arms  16  which carry tilling members (e.g. disc blades  18 ) may be at least approximately the same length as the width covered in each pass of plough  12 . 
         [0034]    In some embodiments, portion  25  is slightly longer than the width of each pass of plough  12  to provide some overlap between the strips tilled in successive passes of tilling apparatus  15 . Although farmers like to do a neat job of field preparation, ploughing does not require high precision. Portion  25  is offset from a centerline of tractor  10  to coincide with an adjacent strip of land that has been ploughed in a previous pass of plough  12 . Portions  25  may be offset by the same amount respectively to left and right sides of the tractor centerline. 
         [0035]    In the illustrated embodiment, when the corresponding frame  33 R or  33 L is in its lowered configuration, the corresponding portion  25  does not extend significantly into the current path of plough  12 . The tilling members of tilling apparatus  15  are arranged so as to leave a gap between the strips that can be tilled by portions  25 . In the gap there are no tilling members (or in the alternative any tilling members that may be present for other applications are mounted by a retraction mechanism that may be operated to keep such tilling members retracted away from the ground to allow for operation of tilling apparatus  15  as described herein). In the illustrated embodiment, tilling members of either one of portions  25  may be engaged with the ground to till the soil without bringing any tilling members into engagement with the ground in a strip extending more-or-less the width of plough  12 . This allows plough  12  to work on clean, un-cut soil. Apparatus  15  may be configured such that, with plough  12  configured to plough to one side, when the arm  16 R,  16 L corresponding to that ploughing direction is in its lowered configuration, the corresponding portion  25  may have its innermost edges in line with or nearly in line with the edge of the strip being currently ploughed by plough  12  and extend outwardly (away from the centreline of tractor  10 ) from that point. 
         [0036]    In the illustrated embodiment, when a frame  33 R or  33 L is in its lowered position, the corresponding portion  25  begins approximately even with the outside edges of tires  11  of tractor  10 . Leaving at least part of the track of tires  11  untilled is advantageous since the soil on which tires  11  drive can remain undisturbed by tilling apparatus  15 , thereby maintaining traction. 
         [0037]    Advantageously, apparatus  15  may be configured such that, when a right arm  16 R is in its lowered configuration, the corresponding tilling members are positioned to engage the ground in a first strip that is offset to the right side of tractor  10  and when left arm  16 L is in its lowered configuration, the corresponding tilling members are positioned to engage the ground in a second strip that is offset to the left side of the tractor and the first and second strips are spaced apart from one another by a third strip. Advantageously the third strip may extend into the track of tires  11  past the inner edges of tires  11 . In some embodiments, the track of tires  11  may be entirely within the third strip. Depending upon its width, plough  12  may plough a strip that substantially lies within the third strip. 
         [0038]      FIGS. 3 through 10C  show some details of construction of an example embodiment of tilling apparatus  15 . In the illustrated embodiment, arms  16 R and  16 L respectively comprise frames  33 R and  33 L. 
         [0039]    Apparatus  15  comprises a central frame  30  which includes a coupling  32  for mounting to the front of a tractor  10 . In some example embodiments, coupling  32  comprises a 3-point hitch coupling that couples to a front-mounted 3-point hitch assembly on the front end of tractor  10 . In alternative embodiments, frame  30  could be bolted or otherwise affixed to the front of tractor  10 . 
         [0040]    Swinging frames  33 R and  33 L are pivotally attached to central frame  30 . A disc assembly  34  is attached to each of swinging frames  33 R and  33 L. Disc assembly  34  comprises a member  36  to which is rotatably mounted a shaft  19  which carries disc blades  18 . 
         [0041]    Actuators (for example hydraulic cylinders) are coupled between mounting points on central frame  30  and corresponding mounting points on swinging frames  33 R and  33 L. The illustrated embodiment includes hydraulic cylinders  40 R and  40 L which are respectively coupled to raise and lower swinging frame  33 R and swinging frame  33 L. 
         [0042]    In a simple embodiment, hydraulic cylinders  40 R and  40 L are controlled by means of auxiliary hydraulic circuits (not shown) of a tractor  10 . Control levers for controlling each of these auxiliary hydraulic circuits may be provided in a cab of tractor  10 . By operating the control levers, a driver of the tractor can individually control each of swinging frames  33 R and  33 L to move between its raised and lowered positions and to stay in the selected raised or lowered position. 
         [0043]    Some embodiments provide a more automatic control. In such embodiments, a single control lever or other user interface may be provided which has positions or commands for left frame  33 L down (and right frame  33 R up); right frame  33 R down (and left frame  33 L up); and transport position (both right and left frames  33 L,  33 R up). 
         [0044]    Members  36  may be angled relative to the direction of travel of tractor  10  to provide a desired tilling action. As illustrated in  FIGS. 10A to 10C , some embodiments permit the angles of members  36  to be varied to modify tilling action of disc blades  18 . 
         [0045]    Since only one of left and right arms  16 L and  16 R is being deployed at a time in normal operation, an alternative embodiment as shown in  FIG. 11  has only a single arm that can be swung between left and right sides of a tractor  10 . In the  FIG. 11  embodiment, single arm  50  carries first and second sets  51 L and  51 R of tilling members. Arm  50  can be carried in a central upright position for transport. Additionally, arm  50  can be swung to the left to bring tilling members  51 L into contact with soil on the left-hand side of tractor  10 . Arm  50  can be swung to the right to bring tilling members  51 R into contact with the soil on the right-hand side of the tractor. Any suitable actuator may be applied to swing arm  50  between its positions and to hold arm  50  in a position after that position has been selected. For example, the actuator could comprise a hydraulic motor, a rack and pinion mechanism, a hydraulic piston, or the like. 
         [0046]    Other constructions are also possible. For example, front-mounted tilling members on either side of a tractor  10  may be mounted so that they can be independently lifted away from engagement with the soil or lowered to engage and till the soil by means of a mechanism which lifts and lowers the members in a generally vertical direction. 
         [0047]    Alternative types of tilling members may be provided. For example, motor-driven rotary tiller blades may be mounted in place of disc blades  18 . Such blades may be driven, for example, by means of a hydraulic motor connected to be driven by pressurized hydraulic fluid supplied from tractor  10 . Movable or fixed, driven or non-driven tines may be provided instead of or in addition to disc blades  18 . Instead of being mounted on the front of a tractor  10 , arms  16 R and  16 L could be mounted to sides of tractor  10  so that they can be lowered to bring tilling members into position to till a previously-ploughed strip of soil. 
         [0048]    While it is most efficient to use an implement as described herein together with a tumble plough, some embodiments comprise a single-bottom plough. Such embodiments require only a single arm that can be lowered to bring tilling members into contact with a strip of land ploughed in a previous pass. The single arm may be mounted on the side of the tractor toward which the plough turns the soil. 
         [0049]    Preferably the tilling members are mounted so that, when they engage the ground at least inside edges of tires of the tractor  10  drive on ground that has not been tilled by the tilling members. For example, the tilling members may be mounted so that they till a strip of land beginning just outside of the tractor&#39;s front wheels and extending outward (away from the centerline of the tractor) for the width of the plough being pulled by the tractor or slightly farther. 
         [0050]    Although tractor  10  is depicted as having tires, the invention may be applied using a tractor having tracks. Tractor  10  is not required to be a purpose-built agricultural tractor but may be a crawler tractor or any other vehicle capable of application as described herein. 
         [0051]    While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.