Claims:WE CLAIM:
1. A system (100) for restricting motion of an actuation arm (102) in a vehicle having hydrostatic transmission, said system (100) comprising:
an actuation arm (102) connected to a forward pedal (104) and a reverse pedal (106) of said vehicle at a top portion (103) of the actuation arm (102);
a bearing (108) positioned at a bottom portion (105) of said actuation arm (102) to support said actuation arm (102), the bearing (108) is gripped with said actuation arm (102);
a pair of neutral setting pivot (110) having a first pivot element (112) and a second pivot element (114) with an angle in the range of 800 to 1000 therebetween, said first pivot element (112) connected to said bearing (108);
a bush (118) positioned between the first pivot element (112) and the second pivot element (114), the bush (118) includes a pin (120);
a locking element (122) locking the pin (120) with the bush (118); and
a spring (116) connected to the second pivot element (114) to restrict the motion of the actuation arm (102) thereby keeping the actuating arm (102) in neutral position.

2. The system (100) as claimed in claim 1, wherein said bearing (108) is a roller bearing or a ball bearing.

3. The system (100) as claimed in claim 1, wherein the pin (120) is positioned eccentrically with respect to the axis of said bush (118).
4. The system (100) as claimed in claim 3, wherein the bush (118) includes the locking element (122) for locking said pin (120) with respect to said bush (118).

5. The system as claimed in claim 1, wherein the spring (116) is a tension spring that enables the second pivot element (114) to abut against said bush (118).

6. The system as claimed in claim 1, wherein said second end (105) of the actuation arm (102) has an arced profile.

7. The system as claimed in claim 1, wherein the forward pedal (104) and the reverse pedal (106) are positioned on same side of the actuation arm (102).

8. The system as claimed in claims 1-7, wherein the vehicle includes farm vehicle having hydrostatic transmission.

9. A method (300) of operating the system (100) as claimed in claims 1-8, the method comprises the steps of:
releasing (302) the pressure exerted on said forward pedal (104) and said reverse pedals (106); and
adjusting (304) a position of said actuation arm (102) supported on said bearing (108) by adjusting a pair of neutral setting pivot (110) through a spring (116) and locking element (122).

10. The method as claimed in claim 9, wherein said spring (116) is connected to a second pivot element (114), the spring (116) pulls the second pivot element (114) that include a bush (118) having a pin (120) positioned eccentrically with respect to the axis of said bush (118), the locking element (122) along with the pin (120) restricts the movement of first pivot element (112) thereby preventing rotation of the bearing (108) and keeping the actuation arm (102) at 900 orientation during neutral condition.
Dated this 21st day of April, 2021
For MAHINDRA & MAHINDRA LIMITED
By their Agent

GIRISH VIJAYANAND SHETH IN/PA- 1022
KRISHNA & SAURASTRI ASSOCIATES LLP
, Description:FORM 2

THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003

COMPLETE SPECIFICATION
[see SECTION 10, RULE 13]

A SYSTEM AND METHOD FOR RESTRICTING MOTION OF AN ACTUATION ARM OF A VEHICLE;

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

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

TECHNICAL FIELD OF INVENTION
The present invention relates to a hydrostatic transmission of vehicle and more particularly, to the field of restricting motion of an actuation arm of a vehicle having hydrostatic transmission.
BACKGROUND OF INVENTION
Hydrostatic transmission (HST) systems are widely used in farm vehicles including tractors and off-road vehicles. In such systems, a hydraulic pump or an accumulator drives the motor using the fluid passing through flexible hoses. In hydrostatic transmission, gears are not required for converting rotating mechanical energy from one source to another, when the displacement of pump and motor are fixed, then hydrostatic transmission itself acts as a gearbox. In a hydrostatic transmission system, when the engine runs, it rotates the drive shaft and the input shaft connected thereto. In a closed-circuit system, the movement of this input shaft turns both the charge pump and piston pump. As a result, the charge pump sucks oil from the reservoir to the transmission case. The reciprocating motion of the piston, due to the change in the angle of a swash plate causes the oil to pass through the hoses and towards the motor.

For example, in a tractor with HST, forward and reverse pedals are provided along with actuation lever. The hydrostatic transmission allows a tractor to convert mechanical energy into hydraulic power and then back to mechanical energy. This allows to change the variation in forward and reverse speed by pressing independent pedals defined for forward and backward movement. However, before starting the tractor/ farm vehicle HST trunnion shaft which connected to pedals should be in neutral position to avoid movement of tractor even in neutral condition. When the tractor is under standstill condition, it is observed that any small movement of the actuation arm causes the tractor to move forward or backward direction. Hence, it is required to restrain the movement of tractor during stand-still condition from safety perspective.

Accordingly, there is need of a system that restricts the movement of the actuation arm of the vehicle having hydrostatic transmission.
OBJECT OF THE INVENTION
An object of the present invention is to provide a system to prevent forward or reverse movement of farm vehicle during stand-still condition.
Another object of the invention is to ensure the positional accuracy of the actuation lever in farm vehicle.
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.
SUMMARY OF THE INVENTION
In one aspect, the present invention relates to a system for restricting motion of an actuation arm of a vehicle having hydrostatic transmission. The system includes an actuation arm connected to a forward pedal and a reverse pedal of said farm vehicle at a top portion of the actuation arm. A bearing is positioned at a bottom portion of said actuation arm to support said actuation arm. The bearing has a point contact with said actuation arm. A pair of neutral setting pivot having a first pivot element and a second pivot element with an angle in the range of 800 to 1000 therebetween is positioned such that said first pivot element is connected to said bearing and a spring is connected to the second pivot element., The bearing is a roller bearing or a ball bearing. The first pivot element and said second pivot element include a bush positioned therebetween. Said bush includes a pin positioned eccentrically with respect to the axis of said bush. The bush includes a locking element for locking said pin with respect to said bush. The spring is a tension spring that enables the second pivot element to abut against said bush. The second end of the actuation arm has an arced profile. The forward pedal and the reverse pedal are positioned on same side of the actuation arm. The vehicle includes a farm vehicle having hydrostatic transmission.
In another aspect, the present invention relates to a method of operating the system. In the first steps the pressure exerted on said forward pedal and said reverse pedals is released. In the next step, a position of said actuation arm supported on said bearing is adjusted by adjusting a pair of neutral setting pivot through the spring and the locking element. The position of the actuating arm is 900 when the said farm vehicle is in neutral condition. The spring is connected to a second pivot element.
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.
FIG. 1 illustrates a system for restricting motion of an actuation arm in a vehicle;
FIG. 2 illustrates a front view of the system of FIG. 1; and
FIG. 3 illustrates a method of operating the system of FIG. 1.
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 pivot element” and “Second Pivot Element” used herein in the specification is to be understood with respect to a reference object.

Figure 1 illustrates a system (100) for restricting motion of an actuation arm in a vehicle. The vehicle includes farm vehicles. The system (100) comprises an actuation arm (102) connected to a forward pedal (104) and a reverse pedal (106) of the farm vehicle at a top portion (103) of the actuation arm (102). The forward pedal (104) and the reverse pedal (106) are positioned on the same side of the actuation arm (102). A bearing (108) is positioned at a bottom portion (105) of the actuation arm (102) to support the actuation arm (102). In an embodiment the bearing (108) has a point contact with the actuation arm (102). The bottom portion (105) of the actuation arm (102) has an arced profile. The bearing (108) may be roller bearing or a ball bearing.

In accordance with an embodiment of the present invention, the actuation arm (102) has inverted Y shape. The top portion (103) of the actuation arm (102) includes a hole for fixing the forward pedal (104) and the reverse pedal (106) by a shaft. The actuation arm (102) includes a hole at a middle portion thereof for pivotally fixing the actuation arm (102) to the frame (101) using suitable connection means. The bottom portion (105) of the actuation arm (102) includes two bifurcated arms having a semi-circular slot (107) configured therebetween. The bearing (108) is partially gripped in the slot (107). The actuation arm (102) oscillates over the bearing (108) as the bearing (108) rotates.

In accordance with an embodiment, the system (100) includes a pair of neutral setting pivot (110). The pair of neutral setting pivot (110) comprises a first pivot element (112) and a second pivot element (114) with an angle in the range of 800 to 1000 therebetween. The function of neutral setting pivot (110) is to ensure that the actuation arm is at 90-degree orientation with respect to the horizontal under neutral condition of the vehicle. The neutral condition herein refers to the phase in which forward pedal (104) and reverse pedal (106) are not actuated i. e the movement of the actuation arm (102) is restricted such that the vehicle does not move in any direction. The first pivot element (112) is connected to the bearing (108) at a first end thereof. A second end of the first pivot element (112) is connected to a first end of the second pivot element (114).

A connection point between the first pivot element (112) and the second pivot element (114) includes a bush (118). The bush (118) is placed on a frame (101). The bush (118) comprises a pin (120) positioned eccentrically with respect to the axis of the bush (118). The system (100) further includes a locking element (122) for locking the pin (120) with respect to the bush (118). The second pivot element (114) includes a spring (116) connected thereto at a first end of the spring (116). In this one embodiment, the spring (116) is a tension spring that enables the second pivot element (114) to abut against the bush (118). A second end of the spring (116) is fixed at a predefined location on the frame (101) using a suitable arrangement for fixing.

In accordance with an embodiment, the system (100) disclosed herein is used in Hydro-static transmission of a vehicle, and farm vehicle in particular Hydro-static transmission a gear less transmission system that uses the flow of fluid to induce motion in the vehicle. The actuation of forward pedal (104) or the reverse pedal (106) causes the actuation arm (102) to rotate. The rotation of the actuation arm (102) in-turn causes actuation of the hydraulic fluid tank that releases the hydraulic fluid resulting in movement of the vehicle. The fluid tank or casing may have multiple flow paths and the flow of fluid in these paths can be varied based on the actuation or pressing of the forward pedal (104) or the reverse pedal (106). The forward pedal (104) and the reverse pedal (106) are used to enable the farm vehicle to move in forward and reverse directions respectively.

In accordance with an embodiment, when a user presses, for example the forward pedal (104) the actuation arm (102) that is connected to the forward pedal (104) rotates in a direction to cause the farm vehicle to move forward. The actuation arm (102) is supported by the bearing (108). The neutral setting pivot (110) comprises the first pivot element (112) connected to the bearing (108). The first pivot element (112) ensures that the bearing (108) maintains contact with the actuation arm (102). When the locking element (122) is loosened and rotated with the help of bearing (108) connected to the actuation arm (102), actuation arm (102) rotates in clockwise or anti-clockwise direction. The bush (118) is located between the first pivot element (112) and the second pivot element (114), the bush (118) comprises a pin (120) positioned eccentrically with respect to the axis of the bush. The bush (118) thus forms an eccentric pivot with respect to the pin (120). The locking element (122) is used for locking the pin (120) with respect to the bush (118). The spring (116) is connected to the second pivot element (114). The function of the spring (116) is to ensure that the actuation arm (102) returns to its original position after completion of movement of either forward pedal (104) or reverse pedal (106). During neutral condition of the farm vehicle, the position of the actuating arm (102) is at 900 with respect to the horizonal axis. Thus, under this neutral condition, the farm vehicle does not move and remains steady.

Figure 2 illustrates an exploded view of system (100) for restricting motion of an actuation arm (102) in a vehicle. The actuation arm (102) is connected to a forward pedal (104) and a reverse pedal (106) of the farm vehicle at a first end (103) of the actuation arm (102) as illustrated in Figure. 1. The bearing (108) is located at the second end (105) of the actuation arm (102). The arced profile of the actuation arm (102) causes the actuation arm (102) to maintain contact with the bearing (108). The bearing (108) is held with the help a bolt (201). The bolt (201) also engages with the first pivot element (112) as shown in Figure. 2. The function of the bolt (201) is to support the bearing (108) and to transfer motion between the bearing (108) and the first pivot element (112). The second end of the first pivot element (112) is connected to a bush (118). The bush (118) includes a pin (120) that supports the bush (118) at the other end of the first pivot element (112) and the second pivot element (114). The spring (116) is connected to second pivot element to keep the actuating arm (102) in neutral position. The second end of the spring (116) is connected to a frame (101) of the system (100).

Consider the condition in which a user presses the forward pedal (104) as showing in Fig. 1 to move the vehicle forward. The actuation arm (102) that is connected to the forward pedal rotates in a direction (203) as illustrated in FIG. 2. The actuation arm (102) rotates with the help of bearing (102). The rotation of the actuation arm (102) causes the hydraulic fluid to flow in the system and this causes the tractor to move forward. When the forward pedal (104) is released and the vehicle is no longer in motion, then the vehicle is under neutral condition. In this condition the actuation arm (102) should be at neutral position, that is it should be at 90-degree orientation with respect to the horizontal. This is achieved by the retraction of the spring (116) to cause the first pivot element (112) to rotate the actuation arm (102) with the help of bearing (108) to achieve 90-degree orientation of the actuation arm (102). The spring (116) pulls the second pivot element (114) that include the bush (118) having the pin (120) positioned eccentrically with respect to the axis of said bush (118), locking element (122) along with pin (120) restricts the movement of first pivot element (112) thereby preventing rotation of the bearing (108) and keeping the actuation arm (102) at 900 orientation during neutral condition. With this, under neutral condition the actuation arm (102) does not rotate, and the movement of vehicle is avoided.

Figure 3 illustrates a method (300) of operating the system (100) for neutral setting in the farm vehicle. The method (300) comprises the following steps. In first step (302), the pressure exerted on the forward pedal (104) and the reverse pedals (106) is released. In the next step (304), the position of the actuation arm (102) supported on the bearing (108) is adjusted by adjusting a pair of neutral setting pivot (110) comprising a first pivot element (112) and a second pivot element (114) through a spring (116) and locking element (122). The spring (116) is connected to the second pivot element (114). When the position of the actuating arm (1) is maintained at 900 with respect to the horizontal axis then the neutral condition of the farm vehicle is achieved. During working, under neutral condition of the farm vehicle the forward pedal (112) and reverse pedal (104) are released and the spring (116) that is connected to the second pivot element (114) enables the bearing (108) along with the locking element (122) ensures that the actuating arm (102) that is resting on the bearing (108) does not move rotate further. The locking element (122) along with the pin (120) restricts the movement of the first pivot element (112) and this in turn prevents rotation of the bearing (108) thereby keeping the actuation arm (102) at 900 orientation during neutral condition.

By using the above-mentioned system with hydro-static transmission in farm vehicle it is now possible to prevent movement of the farm vehicle under neutral condition. It is to be noted here that the vehicles referred as in the present disclosure are not limited to farm vehicles and also include vehicles having hydrostatic transmission.
Advantages:
The system of the present invention prevents movement of farm vehicle under neutral condition.
The system of the present invention enables the orientation of the actuation arm of the farm vehicle to be at 90-degree orientation with respect to the horizontal axis under neutral condition of the farm vehicle.
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 pivot element” and “second pivot element”, 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.