WO2011117888A2

WO2011117888A2 - A throttle control mechanism for an off-road vehicle

Info

Publication number: WO2011117888A2
Application number: PCT/IN2011/000195
Authority: WO
Inventors: David Vinoth Chandru; Ibrahim Hasan Mulla; Binesh Ravindran
Original assignee: Mahindra & Mahindra Ltd
Priority date: 2010-03-26
Filing date: 2011-03-23
Publication date: 2011-09-29
Also published as: WO2011117888A3

Abstract

A throttle control mechanism operably connected within an off-road vehicle includes a rotary sensor having a sensor rod fixedly connected to the input side of the rotary sensor. The sensor rod includes first and second holes formed therein. A first actuator cable has a first end operably connected to an accelerator pedal and a second end attached to a first stopper positioned outside the first hole. Further, a second actuator cable has a first end connected to a manually operated throttle lever and a second end attached to a second stopper positioned outside the second hole. Both the first and the second actuator cables angularly rotate the sensor rod and the input side, generating electric signals by the rotary sensor. The electric signals are received by an electronic control unit connected to the output side of the rotary sensor that operates a fuel injection pump of the off-road vehicle.

Description

TITLE OF THE INVENTION

A throttle control mechanism for an off-road vehicle

FIELD OF THE INVENTION

[0001] The present invention relates generally to throttle control for off-road vehicles and more particularly, to a hand and foot operated throttle control mechanism for such off-road vehicles. DESCRIPTION OF THE BACKGROUND ART

[0002] Acceleration systems of off-road vehicles for example tractors, earth movers, etc., include a foot operated accelerator pedal and a hand operated accelerator lever. Upon actuation of the accelerator pedal and/or the accelerator lever, the accelerator system that is operably connected with the fuel injection pump injects an appropriate amount of fuel into the engine thereby accelerating the !off-road vehicle. It is essential for the off-road vehicles to have both the accelerating options because unlike on-road vehicles the off-road vehicles work in fields that may have even and/or uneven surfaces. When running on uneven surfaces, in order to achieve smooth running of vehicle, better fuel efficiency, and better soil preparation it is desirable to set the accelerator lever at a particular position. This ensures that the engine of the off-road vehicle receives a constant amount of fuel and the vehicle runs at a constant speed irrespective of any obstructions. Thus, the operator is saved from continuously pressing the accelerator pedal. However, at the same time it is not always desirable to run the off-road vehicle at the constant speed. For example, on road conditions where the off-road vehicle is required to run at varying speeds instead of the accelerator lever the accelerator pedal may be used. Therefore, it becomes extremely important to provide both options of the accelerator pedal as well as the accelerator lever in off-road vehicles. [0003] Further, both the accelerator pedal and the accelerator lever are designed in such a way that their actuation is interdependent on each other to offer smooth and better field operations. For example,

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when operating in farm field, it is not only desirable to continuously operate the off-road vehicle at a constant speed but also to achieve further instantaneous acceleration/de-acceleration above the set constant speed. In such a situation, the accelerator lever is typically set in a particular position to set the off-road vehicle running at constant speed. Further, by the usage of accelerator pedal the operator could further instantaneously increase or decrease the speed of the vehicle above the constant speed.

[0004] In conventional off-road vehicles, one of the ways by which both the accelerator lever and the accelerator pedal are operatively interconnected to each is via mechanical linkages. In the mechanical actuation arrangement, preferably both the accelerator lever and the accelerator pedal are operatively interconnected through a quadrant. From the quadrant another linkage is connected to the fuel injection pump for controlling its actuation so that appropriate amount of fuel is supplied to the engine. Such mechanical actuation arrangements have several drawbacks due to presence of more number of mechanical linkages/parts. Due to this, more leverage in controlling the mechanical components/parts is required which may lead in under-acceleration or over-acceleration of the off-road vehicles. Further, relative movements and mechanical play that exist between the joints also poses significant problems. Besides these, wear and tear of the joints between the linkages may affect reliability and durability of the mechanical arrangement over the period. Accordingly, the components/parts and joints are required to be continuously lubricated to ensure smooth and proper actuation of the mechanical arrangement and to avoid malfunctioning. Thus, it is imperative that the complete mechanical arrangement is properly designed so that it offers smooth and efficient actuation of both the hand accelerator and the accelerator pedal.

[0005] In effort to reduce the number of components/parts in the , mechanical linkages arrangements, electronic devices for controlling engine speed have been devised and used within the off-road vehicles for quite some time. In the electronically controlled actuating systems, individual sensors are electrically coupled to the accelerator lever and the accelerator pedal, respectively. Signals from these sensors are received by an Electronic Control Unit (ECU) that is further electrically connected to the fuel injection pump. The ECU, in response to the signals received by the sensors, allows an appropriate amount of fuel to be injected from the fuel injection pump into the engine. However, cost of such electronic systems are quite huge due to the costs associated with the individual sensors and there electrical arrangements with the ECU. Additionally, logic programming in response to the receiving signals from the two or more sensors needs to be added to the ECU, which leads to more calibrations and complexity in the overall system.

[0006] Thus, there is a need to develop an efficient and reliable and yet much simpler acceleration control mechanism that overcomes at least some of the abovementioned drawbacks.

SUMMARY OF THE INVENTION

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[0007] Accordingly disclosed herein is a throttle control mechanism including a rotary sensor having a rotatable input side and an output side, an electronic control unit connected to the output of the rotary sensor and arranged to operate a fuel injection pump of an off-road vehicle, the throttle control mechanism including a sensor rod fixedly connected the input side of the rotary sensor and having a first hole and a second hole formed therein, the sensor rod and the input side angularly rotatable resulting in generation of electric signals by the rotary sensor, the electric signals being received by the electronic control unit, a first actuator cable extending between a first end and a second end and insertable within the first hole of the sensor rod, the first end operably connected to an accelerator pedal rest and the second end attached to

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a first stopper, the first actuator cable freely movable within the first hole upon progressive depression of the accelerator pedal rest to allow the first stopper to displace the sensor rod, and a second actuator cable extending between a first end and a second end and insertable within the second hole, the first end connected to manually operated throttle lever and the second end attached to a second stopper, the second actuator cable freely movable within the second hole when the throttle lever is selectively operated to allow the j

second stopper to displace the sensor rod.

[0008] In some embodiments, both the first actuator cable and the second actuator cable include a relatively thin metallic wire slidably disposed within a relatively thick elastomeric cover, and wherein the first and the second ends of the first actuator and second actuator cables, respectively, include a portion of the metallic wire extending outwardly from the elastomeric cover.

[0009] In some embodiments, the first stopper is fixedly attached to the extended metallic portion of the first actuator cable, and the second stopper is fixedly attached to extended metallic portion of the second actuator cable. [0010] In some embodiments, the accelerator pedal rest includes a linkage rod that extends along a bottom surface of a foot plate to rotatably engage a generally C-shape bracket member attached to the bottom surface, a portion of the linkage rod positioned between a pair of extensions of the bracket member having a plate attached thereto via one of its ends, extended metallic portion at the first end of the first actuator cable tied to an opposite end of the plate. [0011] In some embodiments, the rotary sensor is mounted on a sensor mounting bracket, the sensor mounting bracket extending outwardly from a steering gearbox positioned on top of a clutch housing of the off-road vehicle. i

[0012] In some embodiments, a longitudinal supporting member having a pair of notches formed therein is fixedly attached to the sensor mounting bracket, the longitudinal supporting member extending outwardly from the sensor mounting bracket, and wherein both the first and the second actuator cables positioned within the notches, respectively. [0013] In some embodiments, wherein the rotary sensor is mounted on the sensor mounting bracket in such a manner that the first hole and the second hole of the sensor rod open up along a vertical plane, and wherein the first actuator cable and the second actuator cable are adapted to be vertically received within the first hole and the second hole, respectively. [0014] In some embodiments, the rotary sensor is mounted on the sensor mounting bracket in such a manner that the first hole arid the second hole of the sensor rod open up along a horizontal plane, and wherein the first actuator cable and the second actuator cable are adapted to be horizontally received within the first hole and the second hole, respectively.

[0015] It is to be understood that both the foregoing general description and the following detailed description of the present embodiments of the invention are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the invention and together with the description serve to explain the principles and operation of the invention. A BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above-mentioned and other features and advantages of the various embodiments of the invention, and the manner of attaining them, will become more apparent and will be better understood by reference to the accompanying drawings, wherein:

[0017] FIG. 1 is a perspective view of a throttle control mechanism arranged within an off-road vehicle according to an embodiment of the present invention;

[0018] FIG. 2 is a zoomed-in perspective view of the throttle control mechanism of FIG. 1 ; [0019] FIG. 3 is top elevational view of a rotary sensor having an input side and an output side used within the throttle control mechanism of FIG. 1 ;

[0020] FIG. 4 is side elevational view of a portion of a transcase of the off-road vehicle of FIG. 1 illustrating various depression positions of an accelerator pedal rest and its effect on a linkage rod of the accelerator pedal rest;

[0021] FIG. 5 is a side elevational view of a portion of the throttle control mechanism of FIG. 1 illustrating a first actuator cable in its actuated position and a second actuator cable in its initial position; and

[0022] FIG. 6 is side elevational view of a portion of the throttle control .mechanism of FIG. 1 illustrating the first actuator cable in its released position and the second actuator cable in its actuated position. ,

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] FIGS. 1 and 2 illustrate a throttle control mechanism arranged within an off-road vehicle

100 according to an embodiment of the present invention. The throttle control mechanism includes a first actuator cable 102 that extends between a first end 104 and a second end 106. Preferably, the first actuator cable 102 is formed of a relatively thin metallic wire 107 positioned within a relatively thick elastomeric cover 108. The metallic wire 107 is positioned within the elastomeric cover 108 in such a manner that even with a little pulling force applied, on the metallic wire 107 against the elastomeric cover 108 the metallic wire 107 can be easily pulled outside against the elastomeric cover 107. As such, the metallic wire 107 is slidably positioned within the elastomeric cover 108. Further, at the first end 104, a portion of the metallic material 107 extends outwardly from the elastomeric cover 108. Similarly, at the second end 106 a portion of the metallic material 107 extends outside from the elastomeric cover 108 (See FIGS. 1 and 2). [0024] The first end 104 of the first actuator cable 102 is operably connected to an accelerator pedal rest 109 that is supported over a foot plate 1 10. The foot plate 1 10 is rigidly attached to a transcase 1 12 of the off-road vehicle 100 so that an operator (not shown) could position his foot thereon and comfortably depress and release the accelerator pedal rest 109. As seen in FIG. 1 , the accelerator pedal rest 109 includes an accelerator pedal rod 1 14 that extends along a length of a bottom surface of the foot plate 1 10 and rotatably engaged with a bracket member 1 16. The bracket member 1 16 is of generally C-shape and fixedly attached to the bottom surface of the foot plate 1 10. The bracket member 1 16 has a pair of extensions 1 18 formed at its ends and each of the extensions 1 18 has an opening formed therein. The accelerator pedal rod 1 14 rotatably engages each of the openings of the extensions 1 18 of the bracket member 1 16. [0025] As seen in FIG. 1 , a longitudinal plate 120 is rigidly attached to a portion 122 of the accelerator pedal rod 1 14 positioned between the pair of extensions 1 18. The plate 120 extends downwardly and preferably attached to the accelerator pedal rod 1 14 through one of its ends. An opposite end of the plate 120 has a hole 124 formed therein and the first end 104 of the first actuator cable 102 engages the hole 124. Preferably, as shown in FIGS. 1 and 2, the extended portion of the metallic wire 107 at the first end 104 is tied within the hole 124. However, in various other embodiments, the opposite end of the plate 120 may not have any hole 124 formed therein and the extended portion of the metallic wire 107 may be simply wrapped around the plate 120 at the opposite end. Such alternatives will be considered to be within the scope of the present invention. Further, as seen in FIGS. 1 and 2, a first elastomeric cover stopping member 125 may also be suitably attached to the bottom surface of the foot plate 1 10 or the bracket member 1 16. The first elastomeric cover stopping member 125 is a starting point for the metallic wire 107 extensions at the first end 104 of the first actuator cable 102. Additionally, the first elastomeric cover stopping member 125 also prevents movement of the elastomeric cover 108 when the metallic wire 107 slidably moves within the elastomeric cover 108. Additionally, a first stopper 126 is fixedly attached to the extended portion of the metallic wire 107 at the second end 106 of the first actuator cable 102.

[0026] Upon progressive depression of the accelerator pedal rest 109 by the operator, the portion

122 of the accelerator pedal rod 1 14 positioned within the pair of extensions 1 18 of the bracket member 1 16 is subjected to angular rotation and due to which the plate 120 is angularly displaced in the rearward direction (FIG. 4). This rearward displacement of the plate 120 progressively pulls the metallic wire 107 within the elastomeric cover 108 of the first actuator cable 102. As a result, even though the elastomeric cover 108 remains stationary because of the first elastomeric cover stopping member 125, the first stopper 126 that is positioned in its initial position traverses to reach to its actuated position. Further, as illustrated in FIGS. 1 and 2, a metal piece 128 integrally formed with the accelerator pedal rod 1 14 is positioned adjacent to one of the extensions 1 18 of the bracket member 1 16. The metal piece 128 is rigidly attached to the accelerator pedal rod 1 14 so that upon angular rotation of the accelerator pedal rod 1 14, the metal piece 128 also angularly rotates. Alternatively, the metal piece 128 may be insertable within the accelerator pedal rod 1 14 and positioned adjacent to one of the extensions 1 18. Further, the metal piece 128 is also subjected to a biasing force that may be exerted by a biasing member, for example a spring 130, which is suitably connected to the bottom surface of the foot plate 1 10. Thus, when the accelerator pedal rest 109 is released, the spring 130 by virtue of its state pulls back the metal piece 128 and accordingly the accelerator pedal rod 1 14 back in its normal position. The extended portion of the metallic wire 107 of the first actuator cable 102 is progressively released and the first stopper 126 traverses back to the initial position. In various other embodiments, instead of the spring 130 other biasing members that may sufficiently perform the above functions may also be used and considered to be within the scope of the present invention.

[0027] Furthermore, as seen in FIGS. 1 and 2, the throttle control mechanism also includes a second actuator cable 132 that also extends between a first end 134 and a second end 136. Similar to the first actuator cable 102, the second actuator cable 132 is also formed of the metallic wire 107 positioned within the elastomeric cover 108 in a manner noted above. The extended portion of the metallic wire 107 at first end 134 of the second actuator cable 132 is fixedly attached to an end 138 of a manually operated longitudinal throttle lever 140 via a connecting member 142. Further, the extended portion of the metallic wire 107 at the second end 136 is fixedly attached to a second stopper 144. The throttle lever 140 is positioned adjacent to a steering wheel 146 for the ease of manoeuvrability for the operator (FIG. 1). Further, the throttle lever 140 is supported along a length of a steering column 148 with the help of a friction plate 150 and fastening members 162. As well known in the automobile art, the throttle lever 140 is capable of being rotatably turned in a plurality of selective positions. The steering column 148 is generally rotatably engaged with a steering gear box 152 that is mounted over a steering mounting bracket 154 fixedly attached to a clutch housing 156 of the off-road vehicle 100. Additionally, similar to as noted with respect to the first actuator cable 102, a second elastomeric cover stopping member 157 is suitably connected to the steering gear box 152. The second elastomeric cover stopping member 157 prevents movement of the elastomeric cover 108 of the second actuator cable 132 when the metallic wire 107 slidably moves within the elastomeric cover 108.

[0028] Forward and reverse operation of the throttle lever 140 in selective positions corresponds to accelerating and de-accelerating the off-road vehicle 100 by certain predetermined speed levels. As the extended portion of the metallic wire 107 at the first end 134 is fixedly attached to the throttle lever 140, forward and reverse operation of the throttle lever 140 simultaneously pulls and releases the metallic wire 107. As a result, even though the elastomeric cover 108 remaining relatively stationary, the second stopper 144 moves along with the metallic wire 107. Similar to the actuated and initial positions of the first stopper 126, the second stopper 144 is also positioned in its actuated and initial positions due to the pull and release of the second actuator cable 132. It is to be understood that appropriate material out of which the metallic wire 107 and the elastomeric material 108 are formed may be suitably chosen and will be considered to be within the scope of the present invention.

[0029] According to one embodiment of the present invention illustrated in FIGS. 1 and 2, a sensor mounting bracket 158 extends outwardly, along a horizontal plane, from a housing 160 of the steering gearbox 152. Preferably, the sensor mounting bracket 158 is fixedly connected to the steering gearbox 152 by the use of fastening members 162 and has a flat surface to support a rotary sensor 164 thereon. The rotary sensor 164 is also attached to the sensor mounting bracket 158 through the fastening members 162. FIG. 3 shows a top elevational view of the rotary sensor 164 used within the throttle control mechanism in the various embodiments of the present invention. The rotary sensor 164 includes an input side 166, an output side 168, and a middle portion 170 extending between the input side 166 and the output side 168. As understood in the rotary sensor art, the input side 166 of the rotary sensor 164 is made, as a rotatable component whereas the output side 168 is made as a stationary component. The middle portion 168 of rotary sensor 164 is made from a combination of electric and mechanical components operably connected with each other.

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[0030] The output side 168 of the rotary sensor 164 may be electrically connected to an electronic control unit (ECU) (not shown) so that the ECU could receive appropriate signals from the rotary sensor 164. The ECU may be preferably positioned proximal to the engine of the off-road vehicle 100 and connected to the rotary sensor 164 via wire harness. Further, the ECU is also connected to a Fuel Injection Pump (FIP)

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(not shown) through appropriate electric cables/wire harness. The ECU is pre-programmed in such a manner that corresponding to particular electric signals received from the rotary sensor 164, the ECU determines the required quantity of the fuel that needs to be injected by the FIP into the engine. This calculation in the form of signals is transmitted to the FIP, which injects the necessary amount of fuel in the engine. [0031] As seen in FIG. 3, a longitudinal sensor rod 172 is fixedly connected to the rotatable input side 166 of the rotary sensor 164 via fastening members 162 to facilitate angular rotation of the input side 166. Across a thickness of the sensor rod 172 a first hole 174 and a second hole 176 are formed. As explained below, the first hole 174 receives the extended portion of the metallic wire 107 of the first actuator cable 102. Similarly, the second hole 176 receives the extended portion of the metallic wire 107 of the second actuator cable 132. The first hole 174 and the second hole 176 have diameters greater than the diameters of the metallic wire 107 so as to facilitate free movement of the metallic wire 107 therein. Further, the sensor rod 172 can also be angularly displaced by pre-calculated angle resulting in angular rotation of the input side 166 of the rotary sensor 164. Thus, positions of the first hole 174 and the second hole 176 on the sensor rod 172 are designed according to the extent of degree of rotation of the rotatable input side 166. Further, due to angular rotation of the input side 166, the electrical as well as mechanical components forming the middle portion 170 of the rotary sensor 164 generate electric signals in proportionate to the degree of the angular rotation of the input side 166. Such electric signals are transmitted to the output side 168 of the rotary sensor 164 and finally to the ECU. The detailed constructional explanation of the rotary sensor 164 is not provided as the technical knowledge relating to the sensing devices technology is understood to be well known by a skilled person in the art.

[0032] In the above embodiment where the sensor mounting bracket 158 extends along a horizontal plane, the rotary sensor 164 is positioned in such a manner that the first hole 174 and the second hole 176 open along a vertical plane (See FIGS. 1 and 2). However, in another embodiment, the rotary sensor 164 may be fixedly positioned over the sensor mounting bracket 158 in such a manner that the first hole 174 and the second hole 176 open up along a horizontal plane. Alternatively, in several other embodiments, the sensor mounting bracket 158 may extend outwardly from the housing 160 of the steering gearbox 152 along a vertical plane. In this embodiment, appropriate provisions may be made therein to securely retain the rotary sensor 164 and to ensure that the first and the second holes 174, 176 are opened along the vertical and the horizontal plane, respectively. All such embodiments and alternatives would be considered to be within the scope of the present invention.

[0033] Referring again to FIGS. 1 and 2, the extended portion of the metallic wire 107 of the first actuator cable 102 is insertable vertically within the first hole 174 of the sensor rod 172 so as to position the first stopper 126 outside the first hole 174. Similarly, the second extending metallic wire 107 is also

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insertable vertically within the second hole 176 of the sensor rod 172 so as to position the second stopper 144 outside the second hole 176. As noted above, the extended portion of the metallic wire 107 received within the first hole 174 and the second hole 176 freely move therein without facing any restraint when either/or both the accelerator pedal rest 109 and the throttle lever 140 are operated. In the embodiment where the first hole 174 and the second hole 176 open along the horizontal plane, the extended portion of the metallic wire 107 of both the first and the second actuator cables 102, 132 could be inserted horizontally within the respective holes.

[0034] Further, as seen in FIGS. 1 and 2, a longitudinal support member 178 having a pair of notches 180 formed therein is fixedly attached to the sensor mounting bracket 158. Preferably, the support member 178 extends in the rearward direction towards the transcase 1 12 of the off-road vehicle 100. The elastomeric cover 108 of the first actuator cable 102 and the second actuator cable 132 are insertable within both the notches 180 with little manually exerted pressure. It may be noted that the notches serve two functions with respect to the first actuator cable 102 and the second actuator cable 132. First, the notches 180 act as the supporting end for the elastomeric cover 108 of both the first and the second actuator cables 102, 132 for efficient actuation of the sensor rod 172. Second, the notches 180 also acts as stoppages for the elastomeric covers 108 of both the first and the second actuator cables 102, 132 when the metallic wire 107 slidably moves against them during operation. The overhanging length of both the first actuator cable 102 and the second actuator cable 132 may be adjusted by supporting the cables 102, 132 to the chassis of the off-road vehicle 100 with the usage of support clips 182 (FIGS. 1 and 2). This adjustment ensures that the overhanging wires do not interfere with the surrounding mechanical components/parts.

[0035] FIGS. 4 and 5 are referred to explain the working of the accelerator pedal rest 109 without operating the throttle lever 140. FIG. 4 shows a series of stages when the accelerator pedal rest 109 is depressed for acceleration needs. Due to the depression of the accelerator pedal rest 109, a portion 184 of the accelerator pedal rod 1 14 depresses and the portion 122 of the accelerator pedal rod 1 14 that is positioned within the extensions 1 18 of the bracket member 1 16 is angularly rotated. The longitudinal plate 120, which is fixedly connected to the accelerator pedal rod 1 14, is angularly turned in the rearward direction. This rearward motion of the longitudinal plate 120 progressively pulls the extended portion of the metallic wire 107 at the first end 104 of the first actuator cable 102. Due to tension in metallic wire 107 of the first actuator cable 102, the extended portion of the metallic wire 107 at the second end 106 freely 'moves within the first hole 174 to reach to its actuated position. In the actuated position, the first stopper 126 exerts a downward pulling force on the sensor rod 172 and as a result, the sensor rod 172 is angularly displaced (FIG. 5). Accordingly, the rotatable input side 166 of the rotary sensor 164 is also angularly rotated thereby generating, say a first type of electric signal. Thus, it is understood that on further depressing the accelerator pedal rest 109 the sensor rod 172 will be further displaced and therefore, the input side 166 will be further rotated resulting in generation of, say a second type of electric signal. The first or the second types of electric signals are received by the ECU, which depending on the type of electric signals, allows a fuel injection pump (not shown) to inject necessary amount of fuel into the engine of the off-road vehicle 100.

[0036] With reference to FIG. 5, it is also to be noted that while the accelerator pedal rest 109 is depressed to a particular depth, forward operation of the throttle lever 140, say up to initial few selective positions, will not add to further acceleration of the off-road vehicle 100. This is because due, to the angular displacement of the sensor rod 172, the extended portion of the metallic wire 107 of the second actuator cable 132 freely moves within the second hole 176 and the second stopper 144 is hot able to make any contact with already the displaced sensor rod 172. However, further forward operation of the throttle lever 140 allows the extended portion of the metallic wire 107 to make contact with the displaced sensor rod 172. When the throttle lever 140 is further forwardly operated, the second stopper 144 exerts an additional angular push on the sensor rod 172 and as a result the ECU allows more amount of fuel to be injected into the engine. This results in further acceleration of the off-road vehicle 100.

[0037] FIG. 6 illustrates the situation when the off-road vehicle 100 is running on uneven surfaces and the operator wishes the off-road vehicle 100 to run at a constant speed. In order to do so, the accelerator lever is set at a selective position by the operator. This creates tension in the extended portion of the metallic wire 107 of the second actuator cable 132. Due to this tension the extended portion of the metallic wire 107 at the second end 136 of the second actuator cable 132 freely moves within the second hole 176 of the sensor rod 172. As a result, the second stopper 144, which is positioned in its initial position, reaches to its actuated position. In the actuated position, the second stopper 144 exerts a downward pulling force on the sensor rod 172 as a result of which the sensor rod 172 is angularly displaced (FIG. 6). Accordingly, the input side 166 of the rotary sensor 164 is angularly rotated thereby generating, say a first type of electric signals. As noted above, this electric signal is received by the ECU which allows a fuel injection pump to inject necessary constant amount of fuel, proportionate to the first type of signal, into the engine thereby resulting in acceleration of the off-road vehicle 100. It will however be noted that while the throttle lever 140 is set at a particular position, progressive depression of the accelerator pedal rest 109, say up to some initial depth, will not add to the acceleration of the off-road vehicle 100. This is because the extended portion of the metallic wire 107 of the first actuator cable 102 freely moves within the first hole 174 and the first stopper 126 is not able to make any contact with the sensor rod 172. However, further depression of the accelerator pedal rest 109 allows the first stopper 126 to make contact with the displaced sensor rod 172. On further depression of the acceleration pedal the first stopper 126 will exert an additional angular push on the sensor rod 172 and as a result the ECU will allow a pre-calculated amount of fuel to be i

injected into the engine. This results in further acceleration of the off-road vehicle 100. [0038] From engineering point of view it is understood that the torsional moment required to do work will be high as the line of action of force gets closer and closer to a fixed point. With this consideration, the second actuator cable 132 connected to the throttle lever 140 and disposed within the second hole 176 is formed closer to the point of angular rotation of rotatable input side 166 of the rotary sensor 164. Thus, the force required to displace the sensor rod 172 with the help of the second actuator cable 132 is more and therefore, from the comfort point of view for the operator the second actuator cable 132 is connected to the throttle lever 140. Further, due to the fact that the first hole 174 is formed at some distance from the line of

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action of force, the force required to displace the sensor rod 172 with the help of the first actuator cable 102, insertable within the first hole 174, is relatively less. Precisely, for this reason the first actuator cable 102 is operably connected to the accelerator pedal rest 109. [0039] It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. Thus it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims

CLAIMS:

1. A throttle control mechanism including a rotary sensor having a rotatable input side and an output side, an electronic control unit connected to the output of the rotary sensor "and arranged to operate a fuel injection pump of an off-road vehicle, the throttle control mechanism comprising:

a sensor rod fixedly connected to the input side of the rotary sensor and having a first hole and a second hole formed therein, the sensor rod and the input side angularly rotatable resulting in generation of electric signals by the rotary sensor, the electric signals being received by the electronic control unit;

a first actuator cable extending between a first end and a second end and insertable within the first hole of the sensor rod, the first end operably connected to an accelerator pedal rest and the second end attached to a first stopper, the first actuator cable freely movable within the first hole upon progressive depression of the accelerator pedal rest to allow the first stopper to displace the sensor rod; and

a second actuator cable extending between a first end and a second end and insertable within the second hole, the first end connected to manually operated throttle lever and the second end attached to a second stopper, the second actuator cable freely movable within the second hole when the throttle lever is selectively operated to allow the second stopper to displace the sensor rod.

2. The throttle control mechanism according to claim 1 , wherein both the first actuator cable and the second actuator cable include a relatively thin metallic wire slidably disposed within a relatively thick elastomeric cover, and wherein the first and the second ends of the first actuator and second actuator cables, respectively, include a portion of the metallic wire extending outwardly from the elastomeric cover.

3. The throttle control mechanism according to claim 2, wherein the first stopper is fixedly attached to the extended metallic portion of the first actuator cable, and the second stopper is fixedly attached to extended metallic portion of the second actuator cable.

4. The throttle control mechanism according to claim 2, wherein the accelerator pedal rest includes a linkage rod that extends along a bottom surface of a foot plate to rotatably engage a generally C-shape bracket member attached to the bottom surface, a portion of the linkage rod positioned between a pair of extensions of the bracket member having a plate attached thereto via one of its ends, extended metallic portion at the first end of the first actuator cable tied to an opposite end of the plate.

5. The throttle control mechanism according to claim 1 , wherein the rotary sensor is mounted on a sensor^' mounting bracket, the sensor mounting bracket extending outwardly from a steering gearbox positioned on top of a clutch housing of the off-road vehicle.

6. The throttle control mechanism according to claim 5, wherein a longitudinal supporting member having a pair of notches formed therein is fixedly attached to the sensor mounting bracket, the longitudinal supporting member extending outwardly from the sensor mounting bracket, and wherein both the first and the second actuator cables positioned within the notches, respectively.

7. The throttle control mechanism according to claim 5, wherein the rotary sensor is mounted on the sensor mounting bracket in such a manner that the first hole and the second hole of the sensor rod open up along a vertical plane, and wherein the first actuator cable and the second actuator cable are adapted to be vertically received within the first hole and the second hole, respectively.

8. The throttle control mechanism according to claim 5, wherein the rotary sensor is mounted on the sensor mounting bracket in such a manner that the first hole and the second hole of the sensor rod open up along a horizontal plane, and wherein the first actuator cable and the second actuator cable are adapted to be horizontally received within the first hole and the second hole, respectively.