Claims:We claim:
1. A reverse speed locking system (151) for limiting the vehicle speed during its operation in reverse direction at high speed gear ratio, comprising of : atleast a stationary plate (152), positioned adjacent to the high and medium(168) rail in the transmission system (169); atleast a movable plate (153), positioned in parallel with the said stationary plate (152), wherein said movable plate (153) is provided with a first end (154) and a second end (155); a plurality of coupling tube (156a,156b), wherein said each of the coupling tube is provided at the inner surface of the said stationary plate (152) and the said movable plate (153); atleast a connector (157), provided with a first end (158) and a second end (159), wherein said first end (158) of the connector is operatively coupled to the said second end (155) of the movable plate (153); atleast a lever (160) provided with a first end (161) and a second end (162), wherein said first end (161) of the lever (160) is operatively fastened to the said second end (159) of the connector (157), wherein said second end (162) of the lever (160) is operable in forward (163) and reverse (164) direction with respect to the vehicle direction.

2. A reverse speed locking system (151), as claimed in claim 1, wherein said reverse speed locking system is positioned adjacently and edging high and medium (168) rails in the transmission system (169).

3. A reverse speed locking system (151), as claimed in claim 1, wherein said stationary plate (152) is static about its axis.

4. A reverse speed locking system (151), as claimed in claim 1, wherein said movable plate (153) rotates about its axis with respect to the said stationary plate (152).

5. A reverse speed locking system (151), as claimed in claim 1, wherein said movable plate (153) is rotatably linked to the said stationary plate (152) via the said the coupling tubes (156a,156b).

6. A reverse speed locking system (151), as claimed in claim 1, wherein operation of the said reverse lock system in forward (163) or reverse (164) direction actuates or de-actuates high and medium (168) rails in the transmission system (169).

7. A reverse speed locking system (151), as claimed in claim 1, wherein operation of the said second end (162) of the lever (160) in the reverse (164) direction, stimulates the first end (154) of the movable plate (153) to rotate in a clockwise direction to curb and de-actuate the high and medium (168) rail thereby restricting its movement in the high range (166) direction and limiting the vehicle speed operation in reverse direction at low speed range.

8. A reverse speed locking system (151), as claimed in claim 1, wherein operation of the second end (162) of the lever in the reverse direction (164) de-actuates the high and medium (168) rail in high range (166) direction thereby converting 12 forward and 12 reverse speed transmission system into 12 forward and 8 reverse speed transmission system.

9. A reverse speed locking system (151), as claimed in claim 1, wherein actuation of the high and medium (168) rail in high range direction restricts the lever (160) movement in reverse (164) direction thereby locking the reverse gear at high range speed ratio.

10. A method of operation of the reverse speed locking system (151), comprising steps of :

a) operating the lever (160) in forward (163) or reverse (164) direction, wherein said lever (160) operation enables the movement of the said connector (157);
b) simulating the movement of the movable plate (153) via the said connector (157), wherein said movable plate (153) rotates about its fixed axis in accordance with the connector (157) movement; and
c) actuating or de-actuating the low (165), high and medium (168) rails of the transmission with respect to the movement of the said movable plate (153).

11. The method of operation of the reverse speed locking system (151) for limiting the vehicle speed during its operation in reverse direction at high speed gear ratio, as claimed in claim 10, comprising steps of :
a) operating the lever (160) in reverse direction (164), wherein said lever operation enables the forward movement of the said connector (157);
b) simulating the movement of the movable plate (153) via the said connector (157), wherein said first end (154) of the movable plate rotates in clockwise direction edging the high and medium (168) rail; and
c) de-actuating the high and medium (168) rails of the transmission in high direction, thereby restricting the rail movement in the high range (166) gear direction and limiting the vehicle speed operation in reverse direction at low speed range.

12. The method of operation of the reverse speed locking system (151) for locking the reverse gear at high range speed ratio, as claimed in claim 10, comprising steps of :
a. actuating the he high and medium (168) rail of the transmission system in high range (166) direction;
b. restricting the movement of the movable plate (153), wherein said first end (154) of the movable plate remains non-rotatable; and
c. preventing the lever (160) movement in reverse (164) direction thereby locking the reverse gear at high range speed ratio.

13. The method of operation of the reverse speed locking system (151) for locking the reverse gear at high range speed ratio, as claimed in claim 10, wherein mode of operation of the lever is selected from automatic, semi- automatic and/or manual.
, Description:HIGH SPEED REVERSE GEAR LOCKING SYSTEM AND METHOD THEREOF
FILED OF THE INVENTION
The present invention generally relates to a agricultural vehicle speed transmission system, in particular the present invention is related to a locking mechanism in high range gears at reverse condition which prevents high speed reverse gear operation of a vehicle limiting the vehicle speed in reverse direction.
BACKGROUND OF THE INVENTION
In current automotive transmissions, particularly those associated with agricultural and construction equipment it is known to provide several speed ratios in both forward and reverse operation. It is common to operate the engine at a constant speed and vary the speed of the vehicle by means of a transmission having a large number of output speed ratio. In such system, the transmission is usually provided with 12 differing forward and reverse speed ranges. Thus it is frequently desirable to shuttle shift the transmission between forward and reverse gears without changing the output speed of the transmission gearing. Therefore, generally in such type of transmission system a gear change mechanism is provided which operates independently of the forward speed settings so that the tractor can be placed in a reverse gear setting corresponding to any of the forward gear settings.
In some cases, the transmission system is provided with additional speeds in the forward range. The additional forward range speeds are usually provided through higher gear ratios and are selectable by the operator through a single speed control lever. Selection of reverse mode at higher gear ratios is also possible during such lever shift. It is apparent that this large and overspeed gear condition could be detrimental to the vehicle operation leading to safety critical concerns.
It is, therefore, necessary to provide an appropriate means to prevent the operator from selecting a reverse direction while the vehicle is operating in the higher gear ratio and also to limit the speed of the vehicle in reverse direction at higher gear ratio.
Generally, in vehicle transmission shift control device, the reverse lock device acts as a key component for preventing the transmission from directly shifting from the high speed to the reverse gear, and thus is widely used in various types of automobiles. However in actual driving process, due to negligence or mis-operation, the driver may shift the gear position directly to reverse gear of the transmission at high speed. This may cause damage to the reverse gear, which may in turn damage the transmission system resulting in serious accidents and vehicle impairment. In some cases the vehicle at reverse gear travels at relatively high speeds which become difficult to control. Therefore, it is particularly important to add a reverse lock device during the design of the shift control device.
Conventional reverse lock devices mostly comprises of parts that function to oscillate about a fixed axis, similar to the cam mechanism for yaw motion. This configuration can cause the reverse lock to produce a slight deflection of the shifting shaft during the selection process. Long term continuous use of such reverse lock device tends to accumulate small deflections and will eventually result in inaccurate shifting of the shift control device, thereby affecting the normal use of the transmission. Several other reverse lock devices are available in the state of the art.
Indian patent application 201711022908 provides a locking arrangement for restricting engagement of reverse gear in vehicle power transmission unit. The vehicle power transmission unit includes moving a speed shift lever in a direction towards a reverse shifter bush which enables corresponding portion of speed shift lever to engage corresponding portion of first locking element to restrict the engagement of corresponding portion of the speed shift lever with a lever engaging portion of reverse shifter bush. This restrict the movement of speed shift lever towards reverse gear position thereby restricting engagement of the reverse driven gear when range shift lever is in high range position. The locking arrangement also restricts movement of range shift lever towards high range position when reverse driven gear is in engaged position.
Chinese patent document 103775632 discloses a reverse gear locking device of an automobile transmission, comprising of: a flange, a shift shaft, a reverse gear locking rod and a reverse gear locking plate, wherein the shift shaft is in sliding fit with a hole of the flange; the reverse gear locking rod is fixedly connected with the shift shaft; the reverse gear locking rod and the shift shaft conduct axial movement and circumferential reciprocating swing together; and the reverse gear locking rod is locked with the reverse gear locking plate separately. According to the device, the reverse gear locking rod is only stressed in the movement direction, and the movement direction of the reverse gear locking rod is consistent with the axis direction of the shift shaft all the time, so that the deflection effect caused by the device on the shift shaft during gear selection is eliminated.
Chinese patent document 107631023 discloses a reverse gear shaft locking device of a fast locking transmission comprising of : a connecting rod, a sensor, a pressure plate, a pawl, a working pin, a pre-tightening spring, a lock pin, a return spring and a locking gear; the periphery of the locking gear is of a tooth-shaped cylinder structure, and the lock pin is arranged at the upper end of the locking gear; and the sensor is arranged on the connecting rod. The sensor senses the state by a sensitive element so that locking can be timely and accurately carried out when the transmission carries out reversing, and therefore the speed and the response degree of locking are effectively improved.
US patent document 4068540 provides a transmission control for use with a transmission of the type having a first change gear mechanism for establishing a plurality of drive speeds and a second change gear mechanism for establishing either a forward or reverse drive for each of said plurality of drive speeds, said transmission control including: first shift lever means shiftable between a plurality of positions corresponding to each of said plurality of drive speeds; a first tube assembly interconnecting the first shift lever means with the first change gear mechanism; second shift lever means shiftable between forward and reverse positions; and a second tube assembly interconnecting the second shift lever means with the second change gear mechanism, the second tube assembly being coaxially disposed about the first tube assembly; said transmission control means being further characterized by the combination therewith of stop means mounted on the second tube assembly and contactable by the first shift lever means to prevent the transmission from operating in one or more selected reverse speeds.
GB 1496616 discloses a hydrostatic transmission control linkage in a vehicle which prevents reverse movement of the vehicle in a high speed range comprises a valve spool movable by a lever through linkwork to select forward, neutral or reverse, a lever which pivots a link to select a high speed range (position H) or a low speed range (position L) and a plate pivoted by a rod when lever is moved, the link, connected to valve spool, having a projection which abuts plate to prevent engagement reverse when the vehicle is in a high speed range and also, when the vehicle is in reverse, prevents selection of the high speed range. The vehicle may be an industrial or agricultural tractor, a loader, a scraper or an earth mover.
All of the above cited prior-art documents discloses a reverse lock mechanism which restricts the shifting or movement of transmission gear from forward to reverse condition thereby preventing the vehicle movement in reverse direction. In some state of the art reverse locking system, sensors are employed to sense the vehicle position and enable accurate locking of the reverse transmission gear, and few other locking systems minimizes the deflection effect caused during gear selection. But none of the prior-art document discloses a reverse speed locking system which limits the vehicle speed during its operation in reverse direction at high speed gear ratio. The present invention provides a simple mechanical system to lock the high range gears in the reverse direction thereby restricting the vehicle speed operation in the reverse direction. Therefore, the present invention provides a reverse speed locking system which limits the vehicle speed when vehicle is operated in reverse direction at high speed gear ratio. The present system also operates as a speed conversion system which enables the conversion of 12 forward and 12 reverse speed transmission system into 12 forward and 8 reverse speed transmission system.
OBJECTIVES OF THE INVENTION
In view of the deficiencies of the prior art, the primary objective of the present invention is to provide a reverse speed locking system which limits the vehicle speed during its operation in reverse direction at high speed gear ratio.
Another objective of the present invention is to provide a simple mechanical system to lock the high range gears in the reverse direction thereby restricting the vehicle speed operation in the reverse direction.
Still another objective of the present invention is to provide a reverse speed locking system which also operates as a speed conversion system, enabling conversion of 12 forward and 12 reverse speed transmission system into 12 forward and 8 reverse speed transmission system.
Yet another objective of the present invention is to provide a reverse speed locking system which blocks the high range shift during reverse gear shifting.
Accordingly it is highly desirable to provide a means which will prevent high speed reverse operation of an agricultural or industrial vehicle by employing a simple mechanical locking system. The locking system of the present invention also prevents the forward - reverse gear change mechanism of a transmission from being shifted into its reverse mode when the variable speed change gear mechanism of a transmission is disposed in a high gear setting, or alternatively prevent the change gear mechanism from being disposed in a high speed gear setting when the forward - reverse gear setting is disposed in its reverse position. Furthermore, other desirable features and characteristics of the devices, systems and methods of the herein described exemplary embodiments will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.
SUMMARY OF THE INVENTION
The present invention provides a reverse speed locking system for limiting the vehicle speed during its operation in reverse direction at high speed gear ratio, comprises of : atleast a stationary plate, positioned adjacent to the high and medium rail in the transmission system; atleast a movable plate, positioned in parallel with the said stationary plate; a plurality of coupling tube, wherein said movable plate is rotatably linked to the said stationary plate via the said the coupling tubes; atleast a connector, operatively coupled to the said movable plate; atleast a lever operatively fastened to the said connector, wherein said lever is operable in forward and reverse direction with respect to the vehicle direction. Wherein operation of the said reverse lock system in forward or reverse direction actuate or de-actuate the low, high and medium rails.
In an embodiment of the present invention, wherein said reverse speed locking system is positioned adjacently and edging the low, high and medium rails in the transmission system.
In an embodiment of the present invention, wherein operation of the lever in the reverse direction de-actuates the high and medium rail in high range direction thereby restricting the rail movement in the high range gear direction and limiting the vehicle speed operation in reverse direction a low speed range. This blocking of high and medium rail in high range direction converts the 12 forward and 12 reverse speed transmission system into 12 forward and 8 reverse speed transmission system.
In another embodiment of the present invention, wherein actuation of the high and medium rail in high range direction restricts the lever movement in reverse direction thereby locking the reverse gear at high range speed ratio.
An embodiment of the present invention, provides the method of operation of the reverse speed locking system, comprising steps of : operating the lever in either forward or reverse direction. Wherein said lever operation enables the movement of the said connector, which simulates the movement of the movable plate. The said movable plate rotates about its fixed axis in accordance with the connector movement resulting in actuation or de-actuation of the low, high and medium rails of the transmission.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 shows the reverse speed locking system for limiting the vehicle speed during its operation in reverse direction at high speed gear ratio according to the present invention.
Figure 2 represents the reverse speed locking system positioned in the vehicle transmission system according to the present invention.
While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

DETAILED DESCRIPTION OF THEINVENTION WITH RESPECT TO DRAWINGS
The present invention as embodied by a “High speed reverse gear locking system and method thereof" succinctly fulfils the above-mentioned need(s) in the art. The present invention has objective(s) arising as a result of the above-mentioned need(s), said objective(s) being enumerated below. In as much as the objective(s) of the present invention are enumerated, it will be obvious to a person skilled in the art that, the enumerated objective(s) are not exhaustive of the present invention in its entirety, and are enclosed solely for the purpose of illustration. Further, the present invention encloses within its scope and purview, any structural alternative(s) and/or any functional equivalent(s) even though, such structural alternative(s) and/or any functional equivalent(s) are not mentioned explicitly herein or elsewhere, in the present disclosure. The present invention therefore encompasses also, any improvisation(s)/modification(s) applied to the structural alternative(s)/functional alternative(s) within its scope and purview. The present invention may be embodied in other specific form(s) without departing from the spirit or essential attributes thereof.
Throughout this specification, the use of the word "comprise" and variations such as "comprises" and "comprising" may imply the inclusion of an element or elements not specifically recited.
The present invention aims to overcome the defects of the existing reverse gear locking systems by providing a simple mechanical system to lock the high range gears in the reverse direction thereby restricting the vehicle speed operation in the reverse direction. The reverse speed locking system according to the present invention also operates as a speed conversion system, enabling conversion of 12 forward and 12 reverse speed transmission system into 12 forward and 8 reverse speed transmission system.
According to the present invention as embodied in Fig.1, the reverse speed locking system (151) for limiting the vehicle speed during its operation in reverse direction at high speed gear ratio, comprises of : atleast a stationary plate (152), positioned adjacent to the high and medium rail (168) in the transmission system (169), wherein said stationary plate (152) is static about its axis; atleast a movable plate (153), positioned in parallel with the said stationary plate (152), wherein said movable plate (153) is provided with a first end (154) and a second end (155), wherein said movable plate (153) rotates about its axis with respect to the said stationary plate (152); a plurality of coupling tube (156a,156b), wherein said each of the coupling tube (156a & 156b) is provided at the inner surface of the said stationary plate and the said movable plate, wherein said movable plate (153) is rotatably linked to the said stationary plate (152) via the said the coupling tubes (156a & 156b); atleast a connector (157), provided with a first end (158) and a second end (159), wherein said first end (158) of the connector is operatively coupled to the said second end (155) of the movable plate (153); atleast a lever (160) provided with a first end (161) and a second end (162), wherein said first end (161) of the lever is operatively fastened to the said second end (159) of the connector, wherein said second end (162) of the lever is operable in forward (163) and reverse (164) direction with respect to the vehicle direction.
In the preferred embodiment of the present invention, wherein said reverse speed locking system (151) is positioned adjacently and edging high and medium (168) rails in the transmission system (169).
In the preferred embodiment of the present invention, wherein operation of the said reverse lock system (151) in forward (163) or reverse (164) direction allows to actuate the low rail (165).
In the preferred embodiment of the present invention, wherein said high and medium (168) rail is operable in high range (166) and medium range (167) direction.
In the preferred embodiment of the present invention, wherein operation of the second end (162) of the lever in the reverse direction (164), stimulates the first end (154) of the movable plate (153) to rotate in a clockwise direction to curb and de-actuate the high and medium (168) rail thereby restricting its movement in the high range (166) direction. This controls the vehicle speed operation in reverse direction.
In the preferred embodiment of the present invention, wherein operation of the second end (162) of the lever in the reverse direction (164) de-actuates the high and medium (168) rail in high range (166) direction thereby converting 12 forward and 12 reverse speed transmission system into 12 forward and 8 reverse speed transmission system.
In another embodiment of the present invention, wherein actuation of the high and medium (168) rail in high range (166) direction restricts the lever (160) movement in reverse direction (164) thereby locking the reverse gear at high range speed ratio.
In an embodiment of the present invention, method of operation of the reverse speed locking system (151), comprises steps of :
a) operating the lever (160) in either forward (163) or reverse (164) direction, wherein said lever (160) operation enables the movement of the said connector (157);
b) simulating the movement of the movable plate (153) via the said connector (157), wherein the said movable plate (153) rotates about its fixed axis in accordance with the connector (157) movement;
c) actuating or de-actuating high and medium (168) rails of the transmission (169) in accordance with movement of the said movable plate (153).
In an embodiment of the present invention, method of operation of the reverse speed locking system (151) for limiting the vehicle speed during its operation in reverse direction at high speed gear ratio, comprises steps of :
a) operating the lever (160) in reverse direction (164), wherein said lever (160) operation enables the forward movement of the said connector (157);
b) simulating the movement of the movable plate (153) via the said connector (157), wherein said first end (154) of the movable plate (153) rotates in clockwise direction edging the high and medium (168) rail;
c) de-actuating the high and medium (168) rails of the transmission in high direction, thereby restricting the rail movement in the high range (166) gear direction and controlling the vehicle speed operation in reverse direction.
In the preferred embodiment of the present invention, wherein said mode of operation of the lever is selected from automatic, semi- automatic, manual.
In another embodiment of the present invention, actuation of the high and medium (168) rail of the transmission system (169) in high range (166) direction restricts the movement of the first end (154) of the movable plate (153) thereby preventing the lever (160) movement in reverse direction (164) and locking the reverse gear at high range speed ratio. This locking of the reverse gear at high range speed ratio results in conversion of 12 forward and 12 reverse transmission system into a 12 forward and 8 reverse transmission system.
EXAMPLE 1
Limiting the vehicle speed in reverse direction using the reverse speed locking system (151) according to the present invention involves, operating the second end (162) of the lever (160) in reverse direction (164). Wherein said lever (160) operation enables the forward movement of the said connector (157) pulling the movable plate (153) towards the lever. This simulates the rotating motion of the movement of the movable plate (153). This rotates the first end (154) of the movable plate (153) in clockwise direction in downward motion, edging the high and medium (168) rail. This edging de-actuates and blocks the movement of the high and medium rail (168) in high range (166) direction. This enables operation of only the low rail (165) and medium /high rail during the reverse operation, thereby controlling the vehicle speed in reverse direction at high & medium speed only. The vehicle speed in reverse direction is restricted to 20 km/hr.
EXAMPLE 2
Conversion of 12 forward and 12 reverse transmission system into a 12 forward and 8 reverse transmission system using the reverse speed locking system (151) according to the present invention involves, operating the second end (162) of the lever (160) in reverse direction (164). Wherein said lever operation enables the forward movement of the said connector (157) pulling the movable plate (153) towards the lever. This simulates the rotating motion of the movement of the movable plate (153). This rotates the first end (154) of the movable plate in clockwise direction in downward motion, edging the high and medium (168) rail. This edging de-actuates and blocks the movement of the high and medium (168) rail in high range (166) direction. This restricts the movement of the high and medium rail in high range direction and locks the high range gears in the reverse direction thereby converting the 12 forward and 12 reverse transmission system into 12 forward and 8 reverse transmission system.

EXAMPLE 3
Preventing or locking the reverse gear shift during high range gear ratio operation of the vehicle is performed using the reverse speed locking system (151) of the present invention comprises of: actuation of the high and medium rail (168) of the transmission system in high range (166) direction. This moves the high and medium (168) rail in the high range (166) direction. This movement of high and medium rail restricts the rotational movement of the movable plate (153), which in-turn prevents the operation of the lever (160) movement in reverse direction (164). This locks the reverse gear shift during the operation of the vehicle at high range speed ratio i.e, when already the high and medium (168) rail is operated in the high range (166) position, the lever (160) movement is restricted in the reverse direction.
EXAMPLE 4
In automatic mode of operation of the reverse speed locking system according to the present invention additionally comprises of sensors for sensing the vehicle speed in reverse direction and an electronic control unit which is pre-calibrated with a desired vehicle speed in reverse operation and a hydraulic actuating cylinder for lever operation. Based on signals received from the sensors the electronic control unit activates the hydraulic actuating cylinder. Activated hydraulic cylinder enables the lever (160) operation in forward or reverse direction in accordance with the signals received from the sensors, wherein said lever operation enables the movement of the said connector. The connector (157) simulates the rotating movement of the movable plate (153) which rotates about its fixed axis in accordance with the connector movement. This movement of the movable plate (153) actuates or de-actuates the high and medium (168) rails of the vehicle transmission system.
EXAMPLE 5
In automatic mode of operation of the reverse speed locking system (151) according to the present invention for limiting the vehicle speed in reverse direction includes, sensors for sensing the vehicle speed in reverse direction and an electronic control unit which is pre-calibrated with a desired vehicle speed in reverse operation and a hydraulic actuating cylinder for lever operation. The pre-calibrated vehicle speed in reverse direction is restricted to 20 km/hr. Based on signals received from the sensors, when the vehicle speed in reverse direction exceeds 20km/hr, the electronic control unit activates the hydraulic actuating cylinder. Activated hydraulic cylinder enables operation of the second end (162) of the lever (160) in reverse direction (164). Wherein said lever (160) operation enables the forward movement of the said connector (157) pulling the movable plate (153) towards the lever. This simulates the rotating motion of the movement of the movable plate. This rotates the first end (154) of the movable plate in clockwise direction in downward motion, edging the high and medium (168) rail. This edging de-actuates and blocks the movement of the high and medium (168) rail in high range direction. This enables operation of only the low rail (165) during the reverse operation, thereby controlling the vehicle speed in reverse direction at low speed. The vehicle speed in reverse direction is restricted to 20 km/hr.
EXAMPLE 6
In semi-automatic mode of operation of the reverse speed locking system (151) according to the present invention for limiting the vehicle speed in reverse direction includes, sensors for sensing the vehicle speed in reverse direction and an electronic control unit which is pre-calibrated with a desired vehicle speed in reverse operation and an alarm unit for indicating the vehicle speed in reverse direction. The pre-calibrated vehicle speed in reverse direction is restricted to 20 km/hr. Based on signals received from the sensors, when the vehicle speed in reverse direction exceeds 20km/hr, the electronic control unit activates the alarm unit to indicated the high speed of the vehicle in reverse direction. This alerts the operator to operate the second end (162) of the lever in reverse direction (164). Wherein said lever operation enables the forward movement of the said connector (157) pulling the movable plate towards the lever. This simulates the rotating motion of the movement of the movable plate. This rotates the first end (154) of the movable plate in clockwise direction in downward motion, edging the high and medium (168) rail. This edging de-actuates and blocks the movement of the high and medium rail in high range (166) direction. This enables operation of only the low rail (165) (165) during the reverse operation, thereby controlling the vehicle speed in reverse direction at low speed. The vehicle speed in reverse direction is restricted to 20 km/hr.

It will be apparent to a person skilled in the art that the above description is for illustrative purposes only and should not be considered as limiting. Various modifications, additions, alterations, and improvements without deviating from the spirit and the scope of the invention may be made by a person skilled in the art.