Claims:
1. A rotavator assembly (100) for an agricultural vehicle, the assembly comprising:
a hitch (102) for coupling the rotavator assembly (100) to the agricultural vehicle;
a frame (104) connected with the hitch (102)
a first rotor (110) having plurality of blades mounted on the frame (104) for performing primary tillage operation;
a second rotor (112) having plurality of blades mounted at a predetermined distance (111) from the center of first rotor (110) on the frame (104) for performing secondary tillage operation and pulverization, and
a clod cutter (116) disposed between the first rotor (110) and the second rotor (112).

2. The rotavator assembly (100) as claimed in claim 1, wherein the second rotor (112) is disposed at a predetermined height (114) from the surface level of the first rotor (110).

3. The rotavator assembly as claimed in claim 1 wherein the predetermined distance between the first rotor (110) and second rotor (112) is a function of diameter of said first rotor (110) and said second rotor (112).

4. The rotavator assembly (100) as claimed in claim 1, wherein the clod cutter (116) is mounted on a plate (118) positioned between the first rotor (110) and the second rotor (112).

5. The rotavator assembly (100) as claimed in claim 4, wherein the plate (118) comprises a first groove (120) and a second groove (122) to change the position of the clod cutter (116) in order to control the clod size and the load on the rotors (110, 112).

6. The rotavator assembly (100) as claimed in claim 4, wherein the first groove (120) and the second groove (122) comprises locking means to lock the position of the clod cutter (116).

7. The rotavator assembly (100) as claimed in claim 4, wherein the clod cutter (116) is movable from the first groove (120) to the second groove (122) via. a hydraulic mechanism or an electrically actuated mechanism.

8. The rotavator assembly (100) as claimed in claim 1, wherein the first rotor (110) is adapted to rotate in an opposite direction of rotation of the second rotor (112).

9. The rotavator assembly (100) as claimed in claim 1, wherein the first rotor (110) mounted on a first shaft (106) and the second rotor (112) mounted on a second shaft (108) are detachably attached to the frame (104).
, Description:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)

&

THE PATENTS RULES, 2003

COMPLETE SPECIFICATION
[See section 10, Rule 13]

A ROTAVATOR ASSEMBLY FOR A FARM VEHICLE;

MAHINDRA & MAHINDRA LIMITED, A COMPANY REGISTERED UNDER THE INDIAN COMPANIES ACT, 1913, HAVING ADDRESS AT MAHINDRA RESEARCH VALLEY (MRV), MAHINDRA WORLD CITY, PLOT NO: 41/1, ANJUR P.O., CHENGALPATTU – 603004, KANCHEEPURAM DIST., TAMIL NADU, INDIA

THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE NATURE OF THIS INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

FIELD OF INVENTION
The present invention relates to the field of rotavator assembly for an agriculture vehicle.
BACKGROUND OF INVENTION
A rotavator is a farm implement that is attached to an agricultural vehicle and is used for preparation of seed bed. The rotavator uses rotary power to till the soil. The power to the rotavator is delivered with the help of an agricultural vehicle tractor. The rotavator comprises a rotor on which cutting implements are mounted, the cutting implement will cause digging of soil. The rotavator speed is generally higher than the speed of the tractor. This will create a push effect in the tractor also called as negative draft. In case direction of rotation of rotors is opposite to the direction of rotation of wheels in the tractor then the rotavator creates a pull effect. The pull type rotavator is called down cut rotavator, while the push type is called up-cut rotavator. The pull type rotavator will only dig (cut) the soil, while it has the limitation in terms of depth of cut and increase in vibration. In the case of up-cut type, the function of which is to scoop the soil from the bottom, it has the flexibility in terms of depth of cut. In case tillage of soil is more than 150mm then it is called primary tillage, if it is less than 150mm then it is called secondary tillage. Therefore, there is a requirement for a rotavator assembly that performs both primary and secondary tillage efficiently.

OBJECT OF THE INVENTION
An object of the present invention is to provide stage wise breaking/splitting of soil clod, crop residue and separation of clods.
Another object of the invention is to provide a plate with clod cutter for reducing the size of the clod, the plate being static in the rotavator assembly
Another object of the invention is to control the direction of rotation of rotors so as to enable stage wise breaking/splitting of soil clods , crop residue and separation of stones. and optimizing the power requirement by predetermined vertical distance /position of the rotors.

These and other objects and advantages of the present invention will become more apparent from the following description, when read with the accompanying figures of drawing, which are however not intended to limit the scope of the present invention in any way.
BRIEF DESCRIPTION OF DRAWING
The foregoing and other features of embodiments of the present invention will become more apparent from the following detailed description of embodiments when read in conjunction with the accompanying drawings. In the drawings, like reference numerals refer to like elements.
Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it is not intended to limit the scope of the invention to these embodiments.
Figure1 shows a rotavator assembly for an agricultural vehicle; in accordance with an embodiment of the present invention and
Figure 2 illustrates a top view of the rotavator assembly showing the plate comprising the first groove and the second grove in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which shown by way of illustration specific embodiments that may be practiced. These embodiments are described in sufficient detail to enable a person skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, mechanical, and other changes may be made within the scope of the embodiments. Also, the words “comprising,” “having,” “containing,” and “including,” and other similar forms are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. The singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. The following detailed description is, therefore, not be taken as limiting the scope of the invention, but instead the invention is to be defined by the appended claims. The terms “first rotor” and “second rotor” used herein in the specification is to be understood with respect to a reference object.

Figure 1 illustrates a rotavator assembly (100) for an agricultural vehicle. The rotavator assembly (100) comprises a hitch (102) for coupling the rotavator assembly (100) to the agricultural vehicle, a frame (104) connected with the hitch (102), a first rotor (110) having plurality of blades mounted on the frame for performing primary tillage operation. The first rotor (110) is adapted to rotate in the opposite direction of rotation of the second rotor (112). A second rotor (112) having plurality of blades mounted at a predetermined distance (111) from the center of the first rotor (112) on the frame (104) for performing secondary tillage operation and pulverization, and a clod cutter (116) disposed between the first rotor (110) and the second rotor (112). The first rotor (110) is adapted to rotate in the opposite direction of rotation of the second rotor (112). The second rotor (112) is disposed at a predetermined height (114) from the surface level of the first rotor (110). The predetermined distance between the first rotor (110) and second rotor (112) is a function of diameter of the first rotor (110) and the second rotor (112).The predetermined distance (111) can be in the range of one times the diameter of the first rotor (110) /second rotor (112) and upto twice the diameter of the first rotor (110) and the second rotor (112).

The predetermined height (114) depends upon the soil conditions, clod size. In another embodiment the first shaft (106) and the second shaft (108) are detachably attached to the frame (104). The predetermined height (114) between the first rotor (110) and the second rotor (112) reduces the load exerted at the rotors. The predefined height between first rotor (110) and second rotor (112) will be 20-30% of radius of first rotor. This arrangement ensures balancing of soil loads on the rotors – this will reduce the load on second rotor (112) and ensure pulverization of top layer and covering of stones and crop residue beneath the soil.

A clod cutter (116) is disposed between the first rotor (110) and the second rotor (112). In accordance with an embodiment of the present invention, the clod cutter (116) is mounted on a plate (118) positioned between the first rotor (110) and the second rotor (112).The plate (118) comprises a first groove (120) and a second groove (122) to change the position of the clod cutter (116) in order to control the clod size and the load on the rotors (110, 112). In accordance with an embodiment, the first groove (120) and the second groove (122) comprises locking means to lock the position of the clod cutter (116). The locking means may comprise nuts bolts and fasteners. . The profile of the clod cutter (116) ensures that the snap fit arrangement of the locking means will hold the clod cutter (116) either in the first groove (120) or the second groove (122). The clod cutter may be displaced manually from the first groove (120) to the second groove (122). Alternately, the clod cutter (116) may be movable from the first groove (120) to the second groove (122) via. a hydraulic mechanism or an electrically actuated mechanism (not shown).

The function of the first rotor (110) is to perform primary tillage operation. Primary tillage is defined as the first soil tillage after the last harvest. It is normally conducted when the soil is wet enough to allow plowing and strong enough to give reasonable levels of traction. This can be immediately after the crop harvest or at the beginning of the next wet season. Primary tillage operation involves a depth of cut of soil greater than 150mm. The rotor comprises multiple blades and the rotation of the rotor causes the soil to be cut open along with clods. The soil along with the clods is then directed to the clod cutter by the action of rotation of the first rotor (110) .The clod cutter is disposed between the first rotor (110) and the second rotor (112),and comprises cutting edges for breaking down of the clods received from the first rotor (110) . The clod cutter (116) is mounted on a plate (118). The clods along with soil is crushed with the help of clod cutter is then deposited proximal to the second rotor (112).

Figure 2 illustrates a top view of the rotavator assembly (100) showing the plate (118) comprising the first groove and the second grove. The function of the first grove and the second groove is to accommodate the clod cutter (116) in order to control the clod size and the load on the rotors (110, 112). The first groove (120) and the second groove (122) comprises locking means to lock the position of the clod cutter (116). One end of the clod cutter (116) has a profile that is complementary to the inner profile of the first groove (120) or the second groove (122). This enables the clod cutter (116) to attach itself to the first groove (120) or the second groove (120) depending upon the size of clods to be cut.

During working of the rotavator assembly (100) the power from the tractor is delivered to the first rotor (110). The rotation of the first rotor (110) will cause the cutting edges to dig into the soil. The soil is scooped and or cut depending upon the direction of rotation of the first rotor (110). The soil along with clods is then directed towards the clod cutter (116). The function of the clod cutter (116) is to reduce the size of clods. Once the clod size is reduced, these clods along with soil interact with the second rotor (112) which levels the soil leading to preparation of seedbed.

By using the above-mentioned combination of first rotor (110) and second rotor (112) it is now possible to use the rotavator for both primary tillage and secondary tillage operation. Also, by keeping the first rotor (110) and second rotor (112) at different distance from surface level it is now possible to reduce the load experienced by the first rotor (110) and the second rotor (112). This is because while the first rotor (110) will scoop and direct the soil towards the second rotor (112), the second rotor (112) will help in levelling of the soil.

The placing of first rotor (110) and second rotor (112) at predefined height will ensure the flow of soil from front to rear, this also allows the clods and crop residue to settle at subsurface level and get covered with pulverized soil thereby forming seedbed for plants and seeds.

The various types of blades can be mounted on the both the rotors –first rotor blades are defined for soil opening and throwing back /feed it to rear rotor through baffle plate for segregation of rocks, crop residues and soil clods and first degree of pulverization.
The second rotor (112) blades are defined for further fine pulverization of soil clods and crop residue materials.
The number of blades per rotor shaft will be defined based on type of soil, application (dry or wet cultivation) and the speed of rotation of the power take off shaft. The blades may be of L type, C type, J type, and combination. The different type of provisions/arrangement available for mounting of blades on the rotors – will be based on no of blades per flange of rotor, combination of different blades types at first and second rotor for soil opening, pulverisation and residue management.

ADVANTAGES
The advantages of the present invention are as follows:
1. The rotavator assembly enables stagewise break up of clods.
2. The use of first rotor and the second rotor with predetermined height (114) from the surface level helps in levelling of soil along with clod/stone residue.
3. The clod cutter disposed between the first rotor and the second rotor helps to reduce the size of the clods.
4. The rotavator assembly along with the first rotor and second rotor can be used for performing both primary tillage and secondary tillage operation.
5. The plate provided on the rotavator assembly enables clod cutter to be moved between the first groove and the second groove to control the size of the clod.
The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt, for various applications, such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments.
It is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative, of the invention and not as a limitation. The exemplary embodiments described in this specification are intended merely to provide an understanding of various manners in which these embodiments may be used and to further enable the skilled person in the relevant art to practice the invention.
Although, the embodiments presented in this disclosure have been described in terms of its preferred embodiments, the skilled person in the art would readily recognize that these embodiments can be applied with modifications possible within the spirit and scope of the present invention as described in this specification by making innumerable changes, variations, modifications, alterations and/or integrations in terms of materials and method used to configure, manufacture and assemble various constituents, components, subassemblies and assemblies, in terms of their size, shapes, orientations and interrelationships without departing from the scope and spirit of the present invention.
The numerical values given of various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher or lower than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the disclosure unless there is a statement in the specification to the contrary.
Throughout this specification, the word “comprise”, or variations such as “comprises” or “comprising”, shall be understood to imply including a described element, integer or method step, or group of elements, integers or method steps, however, does not imply excluding any other element, integer or step, or group of elements, integers or method steps.
The use of the expression “a”, “at least” or “at least one” shall imply using one or more elements or ingredients or quantities, as used in the embodiment of the disclosure in order to achieve one or more of the intended objects or results of the present invention.
These relative terms are for convenience of description and do not require that the corresponding apparatus or device be constructed or operated in a particular orientation. Terms concerning attachments, coupling and the like, such as “first groove” and “second groove”, refer to a relationship, wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise.