Description:TECHNICAL FIELD
[001] The present disclosure generally relates to three-point linkage assemblies used in agricultural vehicles for linking implements and equipment to the vehicle body, and more particularly, the present disclosure relates to a device for holding and locking a top link of a three-point linkage system of a vehicle, when no implement is attached to the vehicle.
BACKGROUND
[002] Implements or equipment used for agricultural operations are attached to an agricultural vehicle such as a tractor through a three-point linkage. The three- point linkage is a standardised system comprising of three movable arms or links controlled by a hydraulic system integrated into the vehicle. The three movable arms comprise of two lower lifting arms, and an upper or top link attached at centre of the three-point linkage system. The three-point linkage system is designed to shift the weight of the implement, such as a plough, to the vehicle such that more traction is provided to the vehicle. The two lifting arms allow the lowering and lifting of the implement through the hydraulic system, while the top link provides stability and alignment. The top link is rigid and is designed to have adjustable length to set the operating angle and alignment of the implement. Top link is an important component of the three-point linkage system as it provides draft control when the implement is being operated in a rough terrain. To adjust the top link, usually a handle is attached to the top link to facilitate adjustment of height and length of the top link in the three-point linkage system.
[003] When the implement is not attached to the vehicle, the three-point linkage system which is either attached at a rear end or at front end of the vehicle is suspended in a neutral position above the ground level. There are chances that the arms, and specifically the top link, may loosen up due to the movement of the vehicle in rugged or irregular terrain. Since in traditional three-point linkage only the lifting arms are controlled through the hydraulic system, it becomes crucial that the top link is manually secured in a neutral draft position to avoid any damage to the three-point linkage system.
[004] Conventionally, when the implement is not attached to the vehicle, the top link is manually secured in a neutral position above the ground level through various means. Such means include use of straps, wires or chains to secure the top link in a neutral/ stable position. The top link is strapped to a part of the vehicle with the securing means to avoid any damage caused due to the movement of the vehicle. A major drawback of using such means to secure the top link is that, when the vehicle is driven in rugged or uneven terrain, the securing means might come loose. Also, it is tedious to tie and untie the securing means every time the top link is used. It also puts an additional burden of carrying an extra component for securing the top link to the vehicle. In some vehicles, brackets are used to secure or hold the top link in the neutral position. However, due to a lack of adequate securing means, the probability of the top link coming off from the bracket exists, resulting in damage to the three-point linkage system.
[005] Therefore, there is a need for a device to hold and lock the top-link of a three-point linkage system in a neutral position, wherein the mechanism is easily integrated with the vehicle, easy to use, and holds the top link securely in place.
OBJECTS
[006] The principal object of an embodiment of this invention is to provide a device for holding and locking a top link of a three-point linkage system of a vehicle, when no implement is attached to the vehicle.
[007] Another object of an embodiment of this invention is to provide the device for the top link of the three-point linkage system of the vehicle which is integrated onto the vehicle’s body.
[008] Yet another object of an embodiment of this invention is to provide the device for the top link of the three-point linkage system of the vehicle which facilitates ease of locking the top link when no implement is attached to the vehicle, and ease of releasing the top link when the implement is to be attached to the vehicle.
[009] Still another object of an embodiment of this invention is to provide the device for securing the top link in a neutral position.
[010] Still another object of an embodiment of this invention is to provide the device which is easy to use, easy to manufacture, and does not require complex components.
[011] Yet another object of an embodiment of this invention is to provide a method of fabricating a device for holding and locking a top link in a secured position on the vehicle.
[012] These and other objects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the 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
[013] The embodiments herein are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[014] Fig.1 depicts an exploded view of a locking device of a vehicle top link, according to an embodiment of the invention as disclosed herein;
[015] Fig. 2 depicts a perspective view of the locking device having a locking pin is inserted through a first plate of the locking device and attached with a head and a tail part on either side of the locking pin, according to an embodiment of the invention as disclosed herein;
[016] Fig. 3 is a perspective view of the locking device, wherein a locking pin is inserted through a second plate of the locking device and held in a locked position, according to an embodiment of the invention as disclosed herein;
[017] Fig. 4 is a perspective view of a top link of a vehicle secured with the locking device to the vehicle, wherein an arm of the top link is inserted into the locking device, according to an embodiment of the invention as disclosed herein; and
[018] Fig. 5 is a flowchart depicting a method of fabrication of a locking device for a vehicle top link, according to an embodiment of the invention as disclosed herein.

DETAILED DESCRIPTION
[019] 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.
[020] The embodiments herein achieve a locking device for holding and locking a top link of three-point linkage system of a vehicle when no implement is attached to the vehicle. Further, the embodiments herein achieve the locking device which is easy to integrate onto a body of the vehicle and which securely holds the top-link in a predetermined position. Furthermore, the embodiments herein achieve the locking device which is easy to operate and which also facilitates ease of releasing the top link when the top link is required to be used. Moreover, the embodiments herein achieve the locking device in which the top link is secured/ held in a predetermined position by passing and securing a locking member through the top link. Additionally, the embodiments herein achieve the locking device, which is easy to manufacture, easy to use, and does not require complex components. Further, the embodiments herein achieve a method for fabricating a vehicle top link locking device. Referring now to the drawings, and more particularly to Figs. 1 through 5, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.

[021] Generally, in an agricultural vehicle such as a tractor, agricultural implements such as plough, seed drill, etc., are attached to the vehicle through a three-point linkage system. The three-point linkage system is connected to the tractor to facilitate the attachment and adjustment of the implement for carrying out agricultural operations. The three-point linkage system comprises of two side lifting arms and an upper link or top link arm. The lifting arms enable the lowering and lifting of the implement at the required position, meanwhile the top link which is a rigid and adjustable rod, provides stability and desired draft control to the implement. To allow the adjustment of the top link, usually a functional member such as a handle is attached to the top link which makes it easy for the user to rotate and adjust the top link. Conventionally, the lifting arms are operated through a hydraulic system of the vehicle, whereas the top link is not connected to the hydraulic system. Therefore, when the implement is not attached to the vehicle, the position of the top link needs to be adjusted manually so that the top link is protected from any damage caused during motion of the vehicle in a rugged or uneven terrain such as in an agricultural field. Normally, the top link is tied or secured to the body of the vehicle through a securing means such as a wire, brackets, chains, or straps.
[022] Fig.1 depicts an exploded view of a locking device of a vehicle top link, according to an embodiment of the invention as disclosed herein. The locking device (100) provides a secure means to hold the top link of the three-point linkage system of the vehicle in a predetermined position when no implement is attached to said vehicle. According to an embodiment of the invention, the locking device (100) includes a mounting plate (101), a first plate (102), a second plate (103), and a lock pin (104) comprising of a head (104a), a body (104b), a tail part (104c). The first plate (102) defines a bore (102a) centrally in a body of the first plate (102). The bore (102a) is defined such that it allows a passage of the body (104b) of the lock pin (104) through the first plate (102). The first plate (102) is perpendicularly attached to the mounting plate (101). Further, the second plate (103) defines a key slot (103a) of predetermined shape in a body of the second plate (103) at a predetermined position. The second plate (103) is perpendicularly attached to the mounting plate (101) such that the second plate (103) is parallel to the first plate (102). Further, the bore (102a) of the first plate (102) and the key slot (103a) of the second plate (103) are defined on same axis. In an embodiment, the lock pin (104) includes a tubular body (104b) having predetermined dimensions. The head (104a) is attached towards a first end of the body (104b) of the lock pin (104) and the tail part (104c) is attached towards a second end of the body (104b) of the lock pin (104). The length of the body (104b) of the lock pin (104) is such that it extends from an outer side of the first plate (102) to an outer side of the second plate (103). Further, the head (104a) of the lock pin (104) is attached to the body (104b) of the lock pin (104) such that when the lock pin (104) inserted through the first plate (102), the head (104a) is positioned at the outer side of the first plate (102). In another embodiment of the invention, the locking device may comprise of a plurality of first plates and a plurality of second plates attached perpendicularly to the mounting plate and aligned parallel to each other, and wherein the lock pin is inserted through the plurality of first plates and plurality of second plates for securing the top link in a predetermined position.
[023] Fig. 2 depicts a perspective view of the locking device having a locking pin is inserted through a first plate of the locking device and attached with a head and a tail part on either side of the locking pin, according to an embodiment of the invention as disclosed herein. In an embodiment, the tail part (104c) is attached to the body (104b) of the lock pin (104) after inserting the second end of the body (104b) of the lock pin (104) through the bore (103a) of the first plate (103). The tail part (104c) has a predetermined dimension and profile such that the lock pin (104) is held in a first position and further inserted through the key slot (103a) of the second plate (103) such that the tail part (104c) is positioned at outer side of the second plate (103). The tail part (104c) has a profile such that it does not pass through the bore (102a) of the first plate (102) thereby preventing the lock pin (104) from sliding out of the first plate (102).
[024] Fig. 3 is a perspective view of the locking device, wherein a locking pin is inserted through a second plate of the locking device and held in a locked position, according to an embodiment of the invention as disclosed herein. When the lock pin (104) is inserted through the slot (103a) of the second plate (103) in the first position such that the tail part (104c) passes through the slot (103a) towards the outer side of the second plate (103), the head (104a) is positioned in an initial position. After insertion of the lock pin (104) through the slot (103a) of the second plate (103), the head plate (104a) is released, whereby the lock pin (104) due to the effect of gravity, automatically rotates to a locking position, In an embodiment, the head (104a) of the lock pin (104) is made-up of predetermined mass such that the head (104a) and the tail part (104c) rotate or move to a second position (or locking position), when said head (104a) and the tail part (104c) are released, whereby the lock pin (104) is held at the locked position. In an embodiment, the head (104a) and the tail part (104c) rotate or move about 180 °. To unlock the lock pin (104), the head (104a) is rotated about 180° such that the tail part (104c) passes through the slot (103a) of the second plate (103).
[025] Fig. 4 is a perspective view of a top link of a vehicle secured with the locking device to the vehicle, wherein an arm of the top link is inserted into the locking device, according to an embodiment of the invention as disclosed herein. When the implement is not attached to the vehicle, the top link (200) is not in use. The locking device (100) holds and secures the top link (200) in a neutral position at a predetermined angle, wherein the top link (200) is secured in place with the body of the vehicle. In an embodiment, a connecting member (200a) includes a ring member formed at one end of the connecting member (200a) of the top link (200). The lock pin (104) is inserted through a space defined in the ring member such the ring member is locked between the first plate (102) and the second plate (103) of the locking device (100). When the lock pin (104) rotates to the locking position, the top link (200) is locked through the locking device (100). To release the top link (200) for attaching the implement, the lock pin (104) is rotated to the first position, wherein the ring member is removed from the lock pin (104) and the connecting member (200a) is released.
[026] Fig. 5 is a flowchart depicting a method of fabrication of a locking device for a vehicle top link, according to an embodiment of the invention as disclosed herein. The method (300) includes attaching a first plate (102) and a second plate (103) transversely to a mounting plate (101) (at step 301). Further, the method (300) includes inserting a lock pin (104) having an elongated tubular body (104b) through a bore (102a) defined in said first plate (102) (at step 302). Moreover, the method (300) includes attaching a head (104a) and a tail part (104c) to a first end and a second end of the body (104b) (at step 303). Furthermore, the method (300) includes holding the lock pin (104) in a first position and passing the tail part (104c) attached to the body (104) through a key slot (103a) defined in the second plate (103) (at step 304). Further, the method (300) includes releasing the lock pin (104) to rotate or move said lock pin (104) from said first position to a second position to lock said lock pin (104) in the top link of the vehicle (at step 305).
[027] The technical advantages achieved by the embodiments disclosed herein include ease of operating the locking device for securely holding the top link of a three-point linkage system of a vehicle when no implement is attached to the vehicle, automatic locking of the lock pin therefore eliminating the manual operation, ease of integrating the device with the vehicle, eliminating the need for carrying extra components to secure the top link, and the ease of fabrication of the locking device.
[028] 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 preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
, Claims:We claim,
1. A locking device (100) for holding a top-link (200) of three-point linkage system of a vehicle, comprising:
a mounting plate (101) attached to a body part of said vehicle;
at least one first plate (102) and a second plate (103) connected transversely to said mounting plate (101) at predetermined positions;
a lock pin (104) inserted through said first plate (102) and said second plate (103) to lock said top -link of said three-point linkage system of said vehicle.

2. The locking device (100) as claimed in claim 1, wherein said first plate (102) defines a bore (102a) at a predetermined position, said second plate (103) defines a key slot (103a) at a predetermined position, said bore (102a) and said key slot (103a) are axially aligned to each other, said lock pin (104) is configured to pass through said bore (102a) and said key slot (103a) defined in said first plate (102) and said slot (103a), respectively, to lock said top -link of said three-point linkage system of said vehicle.

3. The locking device (100) as claimed in claim 1, wherein said lock pin (104) is configured to automatically rotates to a locking position, when said lock pin (104) is not operated.

4. The locking device (100) as claimed in claim 1, wherein said lock pin (104) comprises of a head (104a), an elongated tubular body (104b), and a tail part (104c) of predetermined profile and dimensions, wherein said head (104a) is attached towards a first end of said body (104b) of said lock pin (104), and said tail part (104c) is attached towards a second end of said body (104b) of said lock pin (104).
5. The lock pin (104) as claimed in claim 4, wherein said lock pin (104) is inserted through said bore (102a) of said first plate (102) and said slot (103a) of said second plate (103), such that said head (104a) of said lock pin (104) is at an outer side of said first plate (102) and said tail part (104c) of said lock pin (104) is at an outer side of said second plate (103).

6. The locking device (100) as claimed in claim 2, wherein said bore (102a) of said first plate (102) is aligned parallel to said slot (103a) of said second plate (103), such that the lock pin (104) passes through said bore (102a) and said slot (103a), and said body (104b) of said lock pin (104) is laterally aligned between said first plate (102) and said second plate (103).

7. The locking device (100) as claimed in claim 4, wherein said tail part (104c) is formed of a predetermined shape corresponding to a shape of said key slot (103a).

8. The locking device (100) as claimed in claim 4, wherein said tail part (104c) is attached to said second end of said body (104b) of the lock pin (104) after inserting the lock pin (104) through said bore (102a) of said first plate (102), said tail part (104c) is larger than said bore (102a), thereby preventing removal of said lock pin (104) from said bore (102a) of said first plate (102).

9. The locking device (100) as claimed in claim 1, wherein a connecting member (200a) is attached to said top link (200) by inserting said connecting member (200a) through said lock pin (104), such that said connecting member (200a) is securely engaged between said first plate (102) and said second plate (103) through said lock pin (104).
10. The locking device (100) as claimed in claim 9, wherein said connecting member (200a) includes a first end and a second end, said first end is attached to said top link (200) and said second end of said connecting member (200a) is inserted through said lock pin (104).

11. The locking device (100) as claimed in claim 10, wherein said connecting member (200a) includes a ring member attached to said second end, such that said ring member is received by said lock pin (104).

12. The locking device (100) as claimed in claim 1, wherein said locking device (100) is attached to a body of said vehicle at a predetermined position, such that said top link (200) is held in a neutral position at a predetermined angle.

13. A method (300) of fabrication of a locking device for a vehicle top link (200) of a three-point linkage system of a vehicle, comprising:
attaching a first plate (102) and a second plate (103) transversely to a mounting plate (101);
inserting a lock pin (104) having an elongated tubular body (104b) through a bore (102a) defined in said first plate (102);
attaching a head (104a) and a tail part (104c) to a first end and a second end of the body (104b);
holding the lock pin (104) in a first position and passing the tail part (104c) attached to the body (104) through a key slot (103a) defined in the second plate (103); and
releasing the lock pin (104) to rotate or move said lock pin (104) from said first position to a second position to lock said lock pin (104) in the top link of the vehicle.
14. The method (300) as claimed in claim 13, wherein said first plate (102) and said second plate (103) are attached to said mounting plate (101) through welding.

15. The method (300) as claimed in claim 13, wherein said head (104a) and said tail part (104c) are connected to said body (104b) of said lock pin (104) through welding.