Description:TECHNICAL FIELD
[001] The embodiments herein generally relate to a hitch control system in an agricultural vehicle and more particularly, to a position control mechanism for an agricultural implement coupled to a hitch of the agricultural vehicle. Further, embodiments herein relate to a method of providing the position control mechanism for controlling the position of the agricultural implement.

BACKGROUND
[002] Agricultural vehicles such as tractors and other similar vehicles are primarily used in agricultural field operations. One of the most common uses of tractors is to move an agricultural implement through agricultural fields to condition the soil for cultivation. Usually, a three point hitch is used to couple the agricultural implement at a rear end of the agricultural vehicle. A position control mechanism is used for controlling the position (lifting and lowering) of the agricultural implement by lifting and lowering the three point hitch. Further, a cam of the position control mechanism is used to bring back a hydraulic lift system to a neutral position. Fig. 4a depicts a graph plot between a movement of a conventional cam with respect to the position of the three point hitch. The throw of the cam is higher (H1) when the three point hitch is at a lowered position (S1, considered as lower point). The throw of the cam is lower (L1) when the three point hitch is at a raised (lifted) position (R1, considered as higher point). An upper portion (considered as higher point, H1) of the cam is engaged with a cam roller when the three point hitch is at the lowered position (lower point, S1). A bottom portion (considered as lower point, L1) of the cam is engaged with the cam roller when the three point hitch is at the raised position (higher point, R1). Therefore, the motion of the cam is descending from the higher point to the lower point and hence, the cam is called as a retarding type cam. A roller engaging portion of the cam which is movably engaged with the cam roller and a portion of a ram arm which is coupled to a connecting rod of a hydraulic cylinder are facing in same direction. The position control members such as the cam, the cam roller and other position control linkages which are accommodated inside a lift housing (not shown) consumes more packaging space and also increases an overall length of the hydraulic lift system and an overall weight of the agricultural vehicle. For example, the cam roller is disposed in front of the cam, and the rockshaft and an entirety of each lift arm of the three point hitch is disposed to the rear of and spaced away from the cam roller which in turn results in extending of lift arms along a rearward direction of the agricultural vehicle thereby increasing the overall length of the hydraulic lift system and also increases the overall weight of the agricultural vehicle. The conventional cam consumes more space in the lift housing thereby posing difficulty in packaging of other parts of the hydraulic lift system.
[003] Therefore, there exists a need for a position control mechanism for an agricultural implement, which obviates the aforementioned drawbacks. Further, there exists a need for a method for providing a position control mechanism for controlling the position of the agricultural implement, which obviates the aforementioned drawbacks.

OBJECTS
[004] The principal object of embodiments herein is to provide a position control mechanism for an agricultural implement coupled to a hitch of an agricultural vehicle.
[005] Another object of embodiments herein is to provide a method of providing the position control mechanism for controlling the position of the agricultural implement coupled to the agricultural vehicle.
[006] Another object of embodiments herein is to provide the position control mechanism for the agricultural implement, which comprises a position control cam having a rise (ascending) type motion with no dwell.
[007] Another object of embodiments herein is to provide the position control mechanism for the agricultural implement, which comprises position control members being accommodated in a compact lift housing thereby consuming less packaging space and results in reducing an overall length of a hydraulic lift system and an overall weight of the agricultural vehicle.
[008] Another object of embodiments herein is to provide the position control mechanism for the agricultural implement, which comprises a position control cam in which a movement of the position control cam is from a lower point to a higher point when the hitch is moved from a lowered position (lower point) to a raised position (higher point) respectively.
[009] Another object of embodiments herein is to mount the position control cam in front of a position control roller in the position control mechanism thereby reducing an overall length of the hydraulic lift system.
[0010] These and other objects of embodiments herein will be better appreciated and understood when considered in conjunction with following description and accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF DRAWINGS
[0011] The embodiments are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0012] Fig. 1 depicts a cross sectional view of a position control mechanism for an agricultural implement coupled to a hitch of an agricultural vehicle, according to embodiments as disclosed herein;
[0013] Fig. 2 depicts a perspective view of the position control mechanism, according to embodiments as disclosed herein;
[0014] Fig. 3a depicts a cross sectional view of a portion of the position control mechanism, according to embodiments as disclosed herein;
[0015] Fig. 3b depicts a perspective view of a position control cam integrated on an ram arm, according to embodiments as disclosed herein;
[0016] Fig. 4a depicts a graph plot between a movement of the conventional cam with respect to the position of the hitch;
[0017] Fig. 4b depicts a graph plot between a movement of the position control cam with respect to the position of the hitch, according to embodiments as disclosed herein; and
[0018] Fig. 5 depicts a flowchart indicating a method of providing the position control mechanism for controlling the position of the agricultural implement coupled to the agricultural vehicle, according to embodiments as disclosed herein.

DETAILED DESCRIPTION
[0019] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0020] The embodiments herein achieve a position control mechanism for an agricultural implement coupled to a hitch of an agricultural vehicle. Further, embodiments herein achieve a method of providing the position control mechanism for controlling the position of agricultural implement coupled to the agricultural vehicle. Furthermore, embodiments herein achieve the position control mechanism, which comprises position control members being accommodated in a compact lift housing thereby consuming less packaging space and results in reducing an overall length of a hydraulic lift system and overall weight of the agricultural vehicle. Referring now to the drawings Figs 1 to 3b and fig. 4b and fig. 5, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0021] Fig. 1 depicts a cross sectional view of a position control mechanism (100) for an agricultural implement coupled to a hitch of an agricultural vehicle, according to embodiments as disclosed herein. In an embodiment, the position control mechanism (100) comprises a position control lever (102), a position control actuator (104), at least one position control coupler (106), at least one position control coupler spring (108), a position control link (110), a position control roller (112), a position control cam (114C) provided on a ram arm (114), a cam plunger assembly (115), a hitch control valve (116), a rock shaft ((117), (as shown in fig. 1 to fig. 3)) and a main actuator ((118), as shown in fig. 2)). For the purpose of this description and ease of understanding, the position control mechanism (100) is explained herein below with reference to controlling the position (raising and lowering) of the agricultural implement coupled to the hitch such as a three point hitch present in the agricultural vehicle, where the position control members (104, 106, 108, 110, 112, 114C, 115P, 115S) are accommodated in a compact lift housing (100H) thereby consuming less packaging space and results in reducing an overall length of a hydraulic lift system and overall weight of the agricultural vehicle. However, it is also within the scope of the invention to use the position control mechanism (100) for controlling the position (raising and lowering) of the agricultural implement coupled to any other implement mounting structure present in any other vehicles or machines, where less packaging space and reducing the overall length of the hydraulic lift system and overall weight of the agricultural vehicle is required, without otherwise deterring the intended function of the position control mechanism (100) as can be deduced from the description and corresponding drawings.
[0022] The position control lever (102) is adapted to control the raising and lowering of the agricultural implement. The position control actuator (104) is coupled to the position control lever (102). The position control actuator (104) is coupled to a spool (116S), as shown in fig. 1 and fig. 2) of the hitch control valve (116). The position control coupler (106) is adapted to couple the position control link (110) to the position control actuator (104). The position control spring (108) is provided on the position control coupler (106). The position control link (110) is movably supported to a lift housing (100H), as shown in fig. 2). The position control roller (112) is connected to the position control link (110). The position control cam (114C) is movably engaged with the position control roller (112). The ram arm (114C) is mounted onto the rockshaft (117). The ram arm (114C) is coupled to a connecting rod (not shown) of the main actuator (118). The hitch control valve (116) is provided in fluid communication with the main actuator (118). The main actuator (118) is considered to be a hydraulic cylinder.
[0023] The position control cam (114C) is an integral part of the ram arm (114). The position control cam (114C) is adapted to be disposed immediately in front of the position control roller (112) thereby disposing an entirety of the rockshaft (117) and a front portion of each lift arm ((100L), as shown in fig. 3) of the hitch to be disposed in front of and spaced away from the position control roller (112) thereby reducing an overall length of a hydraulic lift system. The main actuator (118), the plurality of lift arms (100L), the hitch control valve (116), the rock shaft (117) and the hitch (not shown) mainly forms the hydraulic lift system.
[0024] A roller engaging portion ((114CF), as shown in fig. 3a and fig. 3b) of the position control cam (114) and a portion ((114F), as shown in fig. 4b) of the ram arm (114) are facing in opposite direction with respect to each other. For example, the roller engaging portion (114CF) of the position control cam (114) is facing in a first direction whereas the portion (114F) of the ram arm (114) is facing in a second direction opposite to the first direction. The roller engaging portion (114CF) of the position control cam (114C) is movably engaged with the position control roller (112). The portion (114F) of the ram arm (114) is coupled to the connecting rod (not shown) of the main actuator (118). In an embodiment, the position control cam (114C) is an advance type offset cam in which the position control cam (114C) has a rise type motion with no dwell.
[0025] A bottom portion (114CL), considered as lower point, as shown in fig. 3a and fig. 3b) of the position control cam (114C) is engaged with the position control roller (112) when the hitch is at lowered position (S2, considered as lower point as shown in fig. 4b). An upper portion (114CU, considered as higher point, as shown in fig. 3a and fig. 3b) of the position control cam (114C) is engaged with the position control roller (112) when the hitch is at raised position (R2, considered as higher point as shown in fig. 4b). The roller engaging portion (114CF) extends from the upper portion (114CU) to the bottom portion (114CL) of the position control cam (114).
[0026] In an embodiment, the cam plunger assembly (115) comprises a cam plunger (115P), a plunger housing (115H) and a resilient means ((115S), (as shown in fig. 3a)). The cam plunger (115P) is adapted to be disposed immediately to the rear of the position control roller (112) and is located opposite to the position control cam (114C). The position control roller (112) is disposed in between the position control cam (114C) and the cam plunger (115P). The cam plunger (115P) is movably engaged with the position control roller (112). The cam plunger (115P) and the resilient means (115S) are adapted to provide an induced spring force on the position control cam (114C) through the position control roller (112) and forces the position control roller (112) to be in physical contact with the position control cam (114C) always. The cam plunger (115P) along with the resilient means (115S) is housed into the plunger housing (115H). For the purpose of this description and ease of understanding, the resilient means (115S) is considered to be a spring.
[0027] Fig. 4b depicts a graph plot between a movement of the position control cam (114C) with respect to the position of the hitch, according to embodiments as disclosed herein. A throw of the position control cam (114C) is defined as the maximum distance through which the position control roller (112) moves with respect to a base circle of the position control cam (114C). The throw of the position control cam (114C) is lower (L2, considered as lower point) when the hitch is at the lowered position (S2, considered as lower point). The throw of the position control cam (114C) is higher (H2, considered as higher point) when the hitch is at the raised position (R2, considered as higher point).
[0028] The working of the position control mechanism (100) during raising of the agricultural implement is as follows. When the position control lever (102) is moved by the user to a raised position, the position control lever (102) moves the position control actuator (104) which in turn moves the spool (116S) of the hitch control valve (116) to the raised position in which fluid (oil) flow to and/or from the main actuator (118) is regulated and the connecting rod of the main actuator (118) is extended thereby rotating the ram arm (114) which in turn rotates the rock shaft (117). The rockshaft (117) in turn raises the lift arms (100L) of the hitch thereby raising the agricultural implement in ratio of movement of the position control lever (102). On the same time when the agricultural implement is moved to the raised position, the position control cam (114C) moves the position control roller (112) thereby moving the position control link (110). The position control link (110) in turn moves the position control actuator (104) through the position control coupler (106). The position control actuator (104) moves the spool (116S) of the hitch control valve (116) to neutral position in which fluid flow to the cylinder of the main actuator (118) is stopped and the fluid in the cylinder is retained to maintain the lift arms (100L) of the hitch in the same raised position thereby maintaining the agricultural implement in the same raised position as required by the user.
[0029] The working of the position control mechanism (100) during lowering of the agricultural implement is as follows. When the position control lever (102) is moved by the user to a lowering position, the position control lever (102) moves the position control actuator (104) which in turn moves the spool (116S) of the hitch control valve (116) to the lowered position in which fluid (oil) flow in the main actuator (118) is regulated and the connecting rod of the main actuator (118) is retracted thereby rotating the ram arm (114) which in turn rotates the rock shaft (117). The rockshaft (117) in turn lowers the lift arms (100L) of the hitch thereby lowering the agricultural implement in ratio of movement of the position control lever (102). On the same time when the agricultural implement is moved to the lowered position, the position control cam (114C) moves the position control roller (112) thereby moving the position control link (110). The position control link (110) in turn moves the position control actuator (104) through the position control coupler (106). The position control actuator (104) moves the spool (116S) of the hitch control valve (116) to the neutral position to maintain the lift arms (100L) of the hitch in the same lowered position thereby maintaining the agricultural implement in the same lowered position as required by the user.
[0030] Fig. 5 depicts a flowchart indicating a method (200) of providing the position control mechanism (100) for controlling the position of the agricultural implement coupled to the agricultural vehicle, according to embodiments as disclosed herein. For the purpose of this description and ease of understanding, the method (200) is explained herein below with reference to providing the position control mechanism (100) for controlling the position (raising and lowering) of the agricultural implement coupled to a three point hitch in the agricultural vehicle such as a tractor. However, it is also within the scope of this invention to practice/ implement the entire steps of the method (200) in a same manner or in a different manner or with omission of at least one step to the method (200) or with any addition of at least one step to the method (200) for providing the position control mechanism (100) for controlling the position (raising and lowering) of the agricultural implement coupled to any other implement mounting structure present in any other vehicles or machines, without otherwise deterring the intended function of the method (200) as can be deduced from the description and corresponding drawings. In an embodiment, the method (200) comprises, disposing a position control cam (114C) immediately in front of a position control roller (112) thereby disposing an entirety of a rockshaft (117) and a front portion of each lift arm (100L) of the hitch in front of and spaced away from the position control roller (112), wherein the position control cam (114C) is an advance type offset cam in which the position control cam (114C) has a rise type motion with no dwell. A roller engaging portion (114CF) of the position control cam (114) is facing in a first direction and a portion (114F) of the ram arm (114) is facing in a second direction opposite to the first direction. The roller engaging portion (114CF) of the position control cam (114) is movably engaged with the position control roller (112). The portion (114F) of the ram arm (114) is coupled to a connecting rod (not shown) of the main actuator (118),
[0031] The method (200) includes providing a cam plunger (115P) immediately to rear of the position control roller (112) and opposite to the position control cam (114C), where the cam plunger (115P) is movably engaged with the position control roller (112). The position control roller (112) is disposed in between the position control cam (114C) and the cam plunger (115P). Further, the method (200) includes loading by, a resilient means, the cam plunger (115P) into a plunger housing (115H).
[0032] The technical advantages of the position control mechanism (100) are as follows. The position control mechanism comprises a position control cam having a rise (ascending) type motion with no dwell. The position control members being accommodated in a compact lift housing thereby consuming less packaging space and results in reducing an overall length of a hydraulic lift system and an overall weight of the agricultural vehicle. A movement of the position control cam is from a lower point to a higher point when the hitch is moved from a lowered position (lower point) to a raised position (higher point) respectively. To mount the position control cam in front of the position control roller in the position control mechanism thereby reducing an overall length of a hydraulic lift system.
[0033] 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 understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modifications within the spirit and scope of the embodiments as described herein.
, Claims:We claim:
1. A position control mechanism (100) for an agricultural implement coupled to an agricultural vehicle, said position control mechanism (100) comprising:
a position control cam (114C) provided on a ram arm (114), said position control cam (114C) adapted to be disposed immediately in front of a position control roller (112); and
a cam plunger assembly (115) comprising a cam plunger (115P) adapted to be disposed immediately to rear of the position control roller (112) and is opposite to said position control cam (114C).

2. The position control mechanism (100) as claimed in claim 1, wherein the position control roller (112) is disposed in between said position control cam (114C) and said cam plunger (115P);
said position control cam (114C) is an advance type offset cam in which said position control cam (114C) has a rise type motion with no dwell;
a roller engaging portion (114CF) of said position control cam (114) is facing in a first direction, where the roller engaging portion (114CF) is movably engaged with the position control roller (112); and
a portion(114F) of the ram arm (114) is facing in a second direction, where the portion (114F) of the ram arm (114) is coupled to a connecting rod of a main actuator (118).

3. The position control mechanism (100) as claimed in claim 1, wherein said position control cam (114C) having,
a bottom portion ((114CL), lower point)) of the position control cam (114C) is engaged with the position control roller (112) when the hitch is at a lowered position (S2, lower point); and
an upper portion ((114CU, higher point)) of the position control cam (114C) is engaged with the position control roller (112) when the hitch at a raised position (R2, higher point).

4. The position control mechanism (100) as claimed in claim 3, wherein a throw of said position control cam (114C) is lower (L2) when the hitch is at the lowered position (S2), lower point); and
the throw of said position control cam (114C) is higher (H2) when the hitch is at the raised position (R2, higher point).

5. The position control mechanism (100) as claimed in claim 1, wherein said cam plunger assembly (115) comprises,
a plunger housing (115H); and
a resilient means (115S) adapted to load said cam plunger (115P) into said plunger housing (115H),
wherein
said cam plunger (115P) and said resilient means (115S) are adapted to provide an induced spring force on said position control cam (114C) through said position control roller (112) and forces said position control roller (112) to be in physical contact with said position control cam 114C) always; and
said cam plunger (115P) along with said resilient means (115S) are housed into said plunger housing (115H).

6. The position control mechanism (100) as claimed in claim 1, wherein said position control cam (114C) disposed immediately in front of the position control roller (112) enables an entirety of a rockshaft (117) and a front portion of each lift arm (100L) of the hitch to be disposed in front of and spaced away from the position control roller (112) thereby reducing an overall length of a hydraulic lift system of the vehicle;
said position control roller (112) is provided on a position control link (110);
the ram arm (114) is mounted on the rock shaft (117); and
each lift arm (100L) is mounted on corresponding end of the rockshaft (117).

7. A method (200) of providing a position control mechanism (100) for controlling the position of an agricultural implement coupled to an agricultural vehicle, said method (200) comprising:
disposing a position control cam (114C) immediately in front of a position control roller (112) thereby disposing an entirety of a rockshaft (117) and a front portion of each lift arm (100L) of the hitch in front of and spaced away from the position control roller (112); and
providing a cam plunger (115P) immediately to rear of the position control roller (112) and opposite to the position control cam (114C),
wherein
the position control cam (114C) is movably engaged with the position control roller (112);
the position control roller (112) is disposed in between the position control cam (114C) and the cam plunger (115P);
the cam plunger (115P) is movably engaged with the position control roller (112);
the position control cam (114C) has a rise type motion with no dwell;
a roller engaging portion (114CF) of the position control cam (114) is facing in a first direction; and
a portion (114F) of the ram arm (114) which is coupled to a main actuator (118), is facing in a second direction opposite to the first direction.

8. The method (200) as claimed in claim 6, wherein said method (200) comprises
loading by, a resilient means, the cam plunger (115P) into a plunger housing (115H),
wherein
the position control cam (114C) is provided on a ram arm (114) which is mounted onto the rock shaft (117).