FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICA TION
(See section 10, rule 13)
1. Title of the invention
A NON REACTION IDLE MECHANISM
2. Applicant(s)
Name Nationality Address
EXCEL CONTROLINKAGE PVT. LTD. INDIA W-65 MIDC INDUSTRIAL AREA, H1NGNA ROAD,
NAGPUR -440016
3. Preamble to the description
COMPLETE SPECIFICATION
The following specification particularly describes the invention and the manner in which it is
to be performed.

The disclosure relates to an idle mechanism for an engine. More particularly the disclosure relates to an automatic idle mechanism for an engine of a construction machine.
BACKGROUND
Construction or work machines include tractors, backhoes and other earth moving or mobile construction equipment. Such machines typically use hydraulic cylinders to control and operate a tool. Hydraulic systems may further be deployed to move the machine as well as rotate the machine body relative its undercarriage, if necessary.
When such construction machines are operating, the throttle of the engine is set at a relatively high level to provide the necessary power for the machine. However, such machines are often in a condition or on standby when no hydraulic function is operated. Typically, such machines are on idle between two tasks or when waiting for another task to complete. When the machines are not being used momentarily or for longer periods of time, the engine is often allowed to continue at the high throttle position consuming a substantial amount of fuel as well as causing undue wear.
Many solutions have been proposed to provide some automatic change in throttle position between a high throttle and a low throttle position when the machine is sensed to be in an idle condition. Such system may be electronic and therefore expensive or may be mechanical/electromechanical and often exceedingly complicated. One such system utilizes hydraulic pressure sensors to determine when the machine is in idle and utilizes a single acting hydraulic cylinder connected to the throttle and the lever for regulating fuel to the engine. When hydraulic pressure is sensed the mechanism returns the engine to a high idle position. However, while electronic based systems are costly to implement, the idle mechanisms typically require some level of operator input in returning the engine to a high idle position.

Figure 1 illustrates one such idle mechanism available in the art. A hand throttle lever is connected by cable to the idle mechanism. A second cable to the idle mechanism also connects an engine throttle. The throttle controls fuel input to the engine (not shown) and consequently the engine RPM. The idle mechanism includes a pressure sensor (not shown) for sensing hydraulic pressure that actuates a solenoid valve. The solenoid valve is connected to a hydraulic cylinder actuating a lever to which the cables from the throttle and the throttle are connected. Movement of the lever, either in response to the solenoid valve or the throttle lever moves the throttle between the low idle and the high idle position. Movements of the throttle lever between the low idle and the high idle position result in corresponding movement of the throttle between the low idle and the high idle position. However, when the idle mechanism actuates the throttle to move from the low idle position to the high idle position, the throttle lever does not necessarily return to its home position for the high idle position on account of frictional losses as well as insufficient force to move the throttle lever to the high idle position. On account of this play, the operator is required to physically move the throttle, often with great effort, back to the high idle position.
Another prior art idle mechanism designed to overcome the limitations of the mechanism described above, illustrated in Figure 2, employs friction pads to restrict movement of the throttle lever in response to the idle mechanism. However, the friction pads require huge efforts form the operator every time a change in the idle setting is required. Alternatively, the operator may loosen the tightening bolts (not shown) to change the idle settings. Both these situations are inconvenient.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
Figure 1 is a schematic diagram of an idle mechanism available in the art. Figure 2 is a schematic diagram of another idle mechanism available in the art designed to overcome the limitations of the mechanism illustrated in Figure 1.

Figure 3 is a schematic diagram of an idle mechanism in accordance with an embodiment of the invention.
Figure 4 is a schematic diagram of an idle mechanism illustrating a throttle as well as the throttle lever set at 'low idle' position in accordance with an embodiment of the invention.
Figure 5 is a schematic diagram of an idle mechanism illustrating a throttle as well as the throttle lever set at 'high idle' position in accordance with an embodiment of the invention.
Figure 6 is a schematic diagram of an idle mechanism illustrating a throttle at 'low idle1 position and the throttle lever set at 'high idle' set in accordance with an embodiment of the invention.
Figure 7 is an isometric view of a coupling mechanism in accordance with a first embodiment of the invention.
Figure 8 is a sectional view of a coupling mechanism in accordance with a first. embodiment of the invention.
Figure 9 is an isometric view of a coupling mechanism in accordance with a second embodiment of the invention.
Figure 10 is a sectional view of a coupling mechanism in accordance with a second embodiment of the invention.
Figure 11 is an isometric view of a coupling mechanism in accordance with a third embodiment of the invention.
Figure 12 is a sectional view of a coupling mechanism in accordance with a third embodiment of the invention.
Figure 13 is an isometric view of a coupling mechanism in accordance with a fourth embodiment of the invention.

Figure 14 is a sectional view of a coupling mechanism in accordance with a fourth embodiment of the invention.
Figure 15 is a sectional view of a coupling mechanism of the fourth embodiment illustrating the degrees of rotation required and the associated tolerances.
SUMMARY
An idle mechanism for regulating a throttle of an engine having a throttle lever is disclosed. The idle mechanism comprises of an actuating lever connected at one end to the throttle such that movement of the actuating lever from a first position to a second position moves the throttle between a low idle mode and a high idle mode. The actuating lever is connected at the other end to the throttle lever by a non-reaction coupling mechanism. The non-reaction coupling mechanism is configured to transmit forces only from the throttle lever to the actuating lever and to prevent forces from the actuating lever to be transmitted back to the throttle lever.
A throttle lever for regulating the throttle of an engine is also disclosed. The throttle lever comprises of a non-reaction coupling mechanism for connecting the throttle lever to the throttle. The non-reaction coupling mechanism configured to transmit forces only from the throttle lever to the throttle and to prevent movement of the throttle lever on account of engine vibrations.
A work machine is also disclosed. The work machine comprises of an engine and a throttle lever for regulating the throttle of the engine. The work machine further comprises of a hydraulic circuit powered by the engine, a sensor to measure the load on the engine by the hydraulic circuit and an idle mechanism.

DETAILED DESCRIPTION
Referring to Figure 3, an idle mechanism in accordance with an embodiment is
disclosed. A first mechanical control cable 100 connects the idle mechanism 200 to a hand
throttle lever 300. A second mechanical control cable 400 connects the idle mechanism 200
to an engine throttle 500. The throttle 500 controls fuel input to the engine (not shown) and
consequently the engine RPM. The idle mechanism includes a pressure sensor 600 for
sensing hydraulic pressure that actuates a solenoid valve 202. The pressure sensor preferably
has an inbuilt adjustable delay timer that controls the delay time between the machine
becoming idle and the actuation of the solenoid valve. It is possible to set the delay between
the pressure sensor 600 detecting no hydraulic load and the transmission of the actuating
signal to the solenoid valve 202. The solenoid valve 202 is connected to a hydraulic cylinder
204 actuating a lever 206 to which the cables 100, 400 from the throttle 500 and the throttle
lever 300 are connected. A resilient member such as spring 208 is provided on the cable 100
and parallel to the hydraulic cylinder 204, Movement of the actuating lever 206, either in
response to the solenoid valve 202 or the throttle lever 300 moves the throttle 500 between
the low idle and the high idle position. The idle mechanism 200 further includes a coupling
system 700 connected between the throttle lever 300 and the first mechanical control cable
100. The coupling system 700 is a Non Reaction system that transmits motion of the throttle
lever 300 to the actuating lever 206 but motion of the actuating lever 206 is not transmitted to
the throttle lever 300. The coupling system 700 is explained in further detail below.
Specifically, with reference to Figure 4 during machine start up both the throttle 500 as well as the throttle lever 300 is set to low idle. For machine operation, the throttle lever 300 is moved to high idle resulting in movement of the throttle 500 to the high idle position, as illustrated in Figure 5. When the pressure sensor detects no hydraulic load an input is given to the solenoid valve 202 after passage of the preset delay time which directs hydraulic flow

to the hydraulic cylinder 204. The hydraulic cylinder 204 moves the auto idle mechanism 200 to the low idle position and correspondingly the throttle 500 moves to the low idle position through movement of the second mechanical control cable 400, as illustrated in Figure 6. The throttle lever 300 and the first mechanical control cable 100 continue to remain in the high idle position even though the spring 208 is stretched due to the non reaction coupling mechanism 700 at the throttle lever 300. As soon as the operator actuates any hydraulic operation, the pressure sensor 600 detects increase in hydraulic load and through the solenoid valve 202, the hydraulic cylinder 204 moves to the high idle position causing the throttle 500 to move back to the high idle position.
Figure 7 illustrates the coupling mechanism in accordance with a first embodiment. The coupling mechanism 700 includes an actuating plate 702 that has plurality of actuating pins 704 projecting from it. Preferably, pairs of actuating pins 704 are mounted on the actuating plate 702 and in the embodiment illustrated, one pair or two actuating pins 704 project from the actuating plate 702. The actuating plate 702 is connected to the throttle lever 300 such that movement of the throttle lever 300 results in movement of the actuating plate 702.
The coupling mechanism further includes a housing 706 with a back surface 708 defining a hollow chamber 710 with internal walls 712. The actuating plate 702 when positioned over the housing 706 forms the front surface (not shown) of the housing 706 with the actuating pins 704 extending into the hollow chamber 710. The housing 706 is preferably tubular defining a circular chamber 710 with an inner wall 712 along its inner circumference. The housing 706 further defines an opening 714 on the back surface 708 in which is mounted a driven shaft 716. A cam 718 is placed within the chamber 710 and is mounted on the driven shaft 716, such that rotation of the cam 718 results in rotation of the driven shaft 716. The cam 718 includes a central opening 720 sized proportionate the driven shaft 716. The cam

718 may be mounted on the driven shaft 716 by way of a keyway, splines or glue. In the embodiment illustrated, the cam 718 is mounted on the driven shaft 716 by splines 722 manufactured in the central opening 720 of the cam 718 and corresponding splines 722 on the external surface of the driven shaft 716.
Referring next to Figure 8, the cam 718 is sized such that it extends across the chamber 728 at one portion while defining at least one cavity 724 between the inner wall 712 of the chamber 710 and the cam 718 at another portion. The cam 718 includes a projection 726 extending in to the cavity 724 towards the inner wall 712 of the housing 706. The projection 726 defines a central surface and a pair of side surfaces abutting the central surface, such that the pair of side surfaces and the central surface together defines a continuous surface on which a roller 730 may roll. The clearance between the central surface and the inner wall 712 of the chamber 710 is greater than the clearance between the side surfaces and the inner walls 712 of the chamber 710. In the embodiment illustrated, the clearance between both side surfaces and the inner walls 712 of the chamber 710 is the same. On either side of the projection 726 a sub cavity 732 is formed that is sized to receive the actuating pin 704 of the actuating plate 702.
A pair of rollers 730, 736 is placed on the projection 726 between the projection 726 and the inner wall 712 of the chamber 710, with each roller 730, 736 positioned at least partly on a side surface. A spring 734 is placed between the rollers 730. 736. The spring 734 is biased such that it pushes the rollers 730, 736 towards the edge of the side surfaces away from the central surface. The rollers 730, 736 are sized such that when completely or partly on the side surface they contact both the housing 706 and the cam 718 and function as a wedge, whereas when positioned on the central surface a clearance is created between the roller 730, 736 and the housing 706 or the roller 730, 736 and the cam 718. At rest, the rollers 730, 736 serve as a wedge and prevent rotation of the cam 718 within the chamber

710. On assembly, the actuating pins 704 are received within the sub cavities 732 on either side of the projection 726 and may or may not be in contact with the rollers 730, 736.
Rotation of the actuating plate 702 in either direction causes an actuating pin 704 to press against the corresponding roller 730, 736, pushing the roller 730, 736 against the spring towards the central surface. When the roller 730, 736 is pushed on to the central surface, it ceases to function as a wedge and the cam 718 is permitted to rotate. Rotation of the cam 718 causes the driven shaft 716 to rotate and thus rotation of the actuating plate 702 is transmitted to the driven shaft 716. On the other hand, rotating the driven shaft 716 in any direction, attempting to rotate the cam 718, causes a roller 730, 736 to further move away from the central surface and get wedged between the cam 718 and the inner wall 712 of the chamber 710. As a result, rotation of the cam 718 is prevented, and consequently rotation of the actuation plate is prevented.
With reference to Figures 9 and 10, a coupling mechanism in accordance with a second embodiment is illustrated. The cam 718 includes at least one pin 738 projecting towards the actuating plate 702. In the embodiment illustrated, a pair of pins 738, 742 is provided on the cam 718 that project towards the actuating plate 702. The actuating plate 702 is provided with corresponding openings 740 formed thereon that receive the pins 738, 742. The openings 740 on the actuating plate 702 are sized larger than the pins 738, 742, such that on assembly a clearance is created between the pins 738, 742 and the edges of the opening.
Rotation of the actuating plate 702 in either direction causes an actuating pin 704 to press against the corresponding roller 730, 736, pushing the roller 730, 736 against the spring 734 towards the central surface. When the roller 730, 736 is pushed on to the central surface, it ceases to function as a wedge and the cam 718 is permitted to rotate. Simultaneously, rotation of the actuating plate 702 to move the roller 730. 736 on to the central surface causes the opening of the actuating plate 702 to engage the pin 738, 742, also causing the cam 718

to rotate. Rotation of the cam 718 causes the driven shaft 716 to rotate and thus rotation of the actuating plate 702 is transmitted to the driven shaft 716. Thus rotation of the actuating plate 702 is transmitted to the cam 718 by both the rollers 730, 736 as well as the dowel pins 738, 742.
On the other hand, rotating the driven shaft 716 in any direction, attempting to rotate the cam 718, causes a roller 730, 736 to further move away from the central surface and get wedged between the cam 718 and the inner wall 712 of the chamber 710. As a result, rotation of the cam 718 is prevented, and consequently rotation of the actuation plate 702 is prevented.
Figures 11 and 12 illustrate the coupling mechanism in accordance with a third embodiment. The actuating plate 702 is provided with two sets of actuating pins 704, 744, The cam 718 is sized such that it extends across the chamber 710 at one portion while defining two cavities 724, 746 between the inner wall 712 of the chamber 710 and the cam 718 at another portion, as best seen in Figure 12. In the embodiment illustrated, the cavities 724, 746 are diametrically opposite each other, separated by the portion of the cam 718 extending across the chamber 710. A projection 726 extends in to each cavity 724, 746 towards the inner wall 712 of the housing 706. On either side of each projection 726, a sub cavity 732 is formed that is sized to receive the actuating pin 704, 744 of the actuating plate 702.
A pair of rollers 730, 736 is placed on each projection 726 between the projection 726 and the inner wall 712 of the chamber 710. On assembly, the actuating pins 704, 744 are received within the sub cavities 732 on either side of each projection 726 and may or may not be in contact with the rollers 730, 736.
Rotation of the actuating plate 702 in either direction causes diametrically opposite actuating pins 704, 744 to press against the corresponding rollers 730, 736, pushing the

rollers 730, 736 against the spring 734 towards the central surface. When the rollers 730, 736 are pushed on to the central surface, they cease to function as a wedge and the cam 738 is permitted to rotate. Rotation of the cam 718 causes the driven shaft 716 to rotate and thus rotation of the actuating plate 702 is transmitted to the driven shaft 716. On the other hand. rotating the driven shaft 716 in any direction, attempting to rotate the cam718, causes diametrically opposite rollers 730, 736 to further move away from the central surface and get wedged between the cam 718 and the inner wall 712 of the chamber 710. As a result, rotation of the cam 718 is prevented, and consequently rotation of the actuation plate 702 is prevented.
With reference to figures 13 and 14, a coupling mechanism in accordance with a fourth embodiment is illustrated. The actuating plate 702 is rigidly connected to a driving shaft 716 that is connected to the throttle lever 300. The fourth embodiment is a modification of the third embodiment on the lines of the second embodiment. In addition to the pair of projections 726, the cam 718 is provided with at least one dowel pin 738 projecting towards the actuating plate 702. In the embodiment illustrated, a pair of dowel pins 738, 742 is provided on the cam 718 that project towards the actuating plate 702. The actuating plate 702 is provided with corresponding openings 740 formed thereon that receive the dowel pins 738, 742. The openings 740 on the actuating plate 702 are sized larger than the dowel pins 738, 742, such that on assembly a clearance is created between the dowel pins 738, 742 and the edges of the opening 740.
Rotation of the actuating plate 702 in either direction causes diametrically opposite actuating pins 704, 744 to press against the corresponding rollers 730, 736, pushing the rollers 730, 736 against the spring 734 towards the central surface. When the rollers 730, 736 are pushed on to the central surface, they cease to function as a wedge and the cam is permitted to rotate. Rotation of the cam 718 causes the driven shaft 716 to rotate and thus

rotation of the actuating plate 702 is transmitted to the driven shaft 716. Simultaneously. rotation of the actuating plate 702 to move the rollers 730, 736 on to the central surface causes the opening 740 of the actuating plate 702 to engage the dowel pins 738, 742. also causing the cam 718 to rotate. Rotation of the cam 718 causes the driven shaft 716 to rotate and thus rotation of the actuating plate 702 is transmitted to the driven shaft 716. Thus rotation of the actuating plate 702 is transmitted to the cam 718 by both the rollers 730, 736 as well as the dowel pins 738, 742.
On the other hand, rotating the driven shaft 716 in any direction, attempting to rotate the cam 718, causes diametrically opposite rollers 730, 736 to further move away from the central surface and get wedged between the cam 718 and the inner wall 712 of the chamber 710. As a result, rotation of the cam 718 is prevented, and consequently rotation of the actuation plate 702 is prevented.
With reference to Figure 15, the actuating pins 704 are shown at the rest position. Clockwise rotation of the actuating plate 702 by two degrees results in the actuating pins 704 contacting the roller 736. A further rotation of two degrees results in the roller 736 pressing spring 734 and moving towards the central surface 750, as well as the opening 740 of the actuating plate 702 contacting the actuating pin 704. A four-degree rotation of the actuating plate 702 is sufficient to rotate the cam 718.
In accordance with an embodiment, the idle mechanism is provided with a delay timer that actuates the solenoid valve 202 for moving the throttle 500 to the low idle position only after a pre-determined time period has lapsed. The delay timer may be set to a few seconds or to a few minutes. The delay timer prevents the engine from unnecessary oscillations between low idle and high idle positions.
In accordance with an embodiment, the throttle lever for regulating the throttle of an engine comprises of a non-reaction coupling mechanism for connecting the throttle lever to

the throttle. The non-reaction coupling mechanism configured to transmit forces only from the throttle lever to the throttle and to prevent movement of the throttle lever on account of engine vibrations.
In accordance with another embodiment, the throttle lever is configured to regulate the throttle of an engine. The engine comprises of an idle mechanism connected to the throttle and configured to move the engine between a low idle mode and a high idle mode in response to the engine load. The throttle lever comprises of a non-reaction coupling mechanism for connecting the throttle lever to the idle mechanism. The one way coupling mechanism is configured to transmit forces only from the throttle lever to the idle mechanism and to prevent forces from the idle mechanism to be transmitted back to the throttle lever.
In accordance with another embodiment, the work machine comprises of an engine and a throttle lever for regulating the throttle of the engine. The work machine further comprises of a hydraulic circuit powered by the engine, a sensor to measure the load on the engine by the hydraulic circuit and an idle mechanism.
In accordance with an embodiment, the work machine may be any construction machine such as tractors, backhoes and other earth moving or mobile construction equipment.
SPECIFIC EMBODIMENTS ARE DESCRIBED BELOW
An idle mechanism for regulating a throttle of an engine having a throttle lever, the idle mechanism comprising an actuating lever connected at one end to the throttle such that movement of the actuating lever from a first position to a second position moves the throttle between a low idle mode and a high idle mode; the actuating lever connected at the other end to the throttle lever by a non-reaction coupling mechanism, the non-reaction coupling mechanism configured to transmit forces only from the throttle lever to the actuating lever and to prevent forces from the actuating lever to be transmitted back to the throttle lever.

Such idle mechanism(s), further comprising a sensor for determining the load on the engine and instructing the idle mechanism to move the engine between a low idle mode and a high idle mode
Such idle mechanism(s), further comprising a hydraulic cylinder and a solenoid valve configured to connect the sensor to the actuating lever.
Such idle mechanism(s), further comprising a control cable for connecting the non-reaction coupling mechanism to the actuating lever.
Such idle mechanism(s). further comprising a resilient member for connecting the actuating lever to the control cable.
Such idle mechanism(s), wherein the actuating lever is connected to the throttle by a control cable.
Such idle mechanism(s), wherein the non-reaction coupling mechanism comprises a housing defining an opening to receive a driven shaft connected to the actuating lever, a cam defining a radial projection positioned within the housing and mounted on the driven shaft; the radial projection comprising a central surface, a first side surface and a second side surface on either side of the central surface, such that the central surface defines a central clearance between the cam and the housing and the first side surface and the second side surface define side clearances between the cam and the housing; the side clearances smaller than the central clearance, a first roller and a second roller positioned between the radial projection and the housing and having a resilient member in between, the resilient member configured to position the first roller at least partly on the first side surface and the second roller at least partly on the second side surface; the first and second rollers sized such that when partly or completely positioned on the side surface the rollers contact the housing and serve as a wedge between the cam and the housing and when positioned on the central surface a gap is formed between the rollers and the housing and a first actuating pin and a

second actuating pin mounted on the actuating member and configured to be received within the housing with the first actuating pin positioned between the cam and the first roller and the second actuating pin positioned between the cam and the second roller; such that rotation of the actuating member causes one of the actuating pins to push the respective roller from the side surface towards the central surface against the resilient member.
FURTHER SPECIFIC EMBODIMENTS ARE DESCRIBED BELOW
A throttle lever for regulating the throttle of an engine comprising a non-reaction coupling mechanism for connecting the throttle lever to the throttle, the non-reaction coupling mechanism configured to transmit forces only from the throttle lever to the throttle and to prevent movement of the throttle lever on account of engine vibrations.
Such throttle lever(s), for regulating the throttle of an engine, the engine comprising an idle mechanism connected to the throttle and configured to move the engine between a low idle mode and a high idle mode in response to the engine load, the throttle lever comprising a non-reaction coupling mechanism for connecting the throttle lever to the idle mechanism, the one way coupling mechanism configured to transmit forces only from the throttle lever to the idle mechanism and to prevent forces from the idle mechanism to be transmitted back to the throttle lever.
Such throttle lever(s), wherein the non-reaction coupling mechanism comprises a housing defining an opening to receive a driven shaft, a cam defining a radial projection positioned within the housing and mounted on the driven shaft; the radial projection comprising a central surface, a first side surface and a second side surface on either side of the central surface, such that the central surface defines a central clearance between the cam and the housing and the first side surface and the second side surface define side clearances between the cam and the housing; the side clearances smaller than the central clearance, a first roller and a second roller positioned between the radial projection and the housing and

having a resilient member in between, the resilient member configured to position the first roller at least partly on the first side surface and the second roller at least partly on the second side surface; the first and second rollers sized such that when partly or completely positioned on the side surface the rollers contact the housing and serve as a wedge between the cam and the housing and when positioned on the central surface a gap is formed between the rollers and the housing and a first actuating pin and a second actuating pin mounted on the actuating member and configured to be received within the housing with the first actuating pin positioned between the cam and the first roller and the second actuating pin positioned between the cam and the second roller; such that rotation of the actuating member causes one of the actuating pins to push the respective roller from the side surface towards the central surface against the resilient member.
Such throttle lever(s), further comprising a control cable for connecting the idle mechanism to the non-reaction coupling mechanism.
FURTHER SPECIFIC EMBODIMENTS ARE DESCRIBED BELOW
A work machine comprising an engine, a throttle lever for regulating the throttle of the engine, a hydraulic circuit powered by the engine, a sensor to measure the load on the engine by the hydraulic circuit and an idle mechanism.
INDUSTRIAL APPLICABILITY
The idle mechanism disclosed overcomes prior art limitations and prevents movement of the engine throttle in response to the idle mechanism from causing corresponding movement of the throttle lever. Operator inputs to restore throttle lever to the high idle setting are not required easing operator comfort. Moreover, play in throttle lever is reduced on account of the idle mechanism. The non-reaction coupling between the idle mechanism and the throttle allows inputs from the throttle lever to be conveyed to the idle mechanism while preventing feedback from the idle mechanism.

The throttle lever with the non-reaction coupling mechanism prevents movement of the throttle lever on account of engine vibrations or any feedback from the engine.
The work machine configured with the idle mechanism and the throttle lever of by described herein significantly improves operation efficiency including fuel savings while also improving operator convenience.

WE CLAIM:
1. An idle mechanism for regulating a throttle of an engine having a throttle lever, the idle mechanism comprising:
an actuating lever connected at one end to the throttle such that movement of the actuating lever from a first position to a second position moves the throttle between a low idle mode and a high idle mode; the actuating lever connected at the other end to the throttle lever by a non-reaction coupling mechanism, the non-reaction coupling mechanism configured to transmit forces only from the throttle lever to the actuating lever and to prevent forces from the actuating lever to be transmitted back to the throttle lever.
2. An idle mechanism as claimed in claim 1 further comprising a sensor for determining the load on the engine and instructing the idle mechanism to move the engine between a low idle mode and a high idle mode.
3. An idle mechanism as claimed in claim 2 further comprising a hydraulic cylinder and a solenoid valve configured to connect the sensor to the actuating lever.
4. An idle mechanism as claimed in claim 1 further comprising a control cable for connecting the non-reaction coupling mechanism to the actuating lever.
5. An idle mechanism as claimed in claim 4 further comprising a resilient member for connecting the actuating lever to the control cable.
6. An idle mechanism as claimed in claim 1 wherein the actuating lever is connected to the throttle by a control cable.
7. An idle mechanism as claimed in claim 1 wherein the non-reaction coupling mechanism comprises:
a housing defining an opening to receive a driven shaft connected to the actuating lever;

a cam defining a radial projection positioned within the housing and mounted on the driven shaft; the radial projection comprising a central surface, a first side surface and a second side surface on either side of the central surface, such that the central surface defines a central clearance between the cam and the housing and the first side surface and the second side surface define side clearances between the cam and the housing; the side clearances smaller than the central clearance;
a first roller and a second roller positioned between the radial projection and the housing and having a resilient member in between, the resilient member configured to position the first roller at least partly on the first side surface and the second roller at least partly on the second side surface; the first and second rollers sized such that when partly or completely positioned on the side surface the rollers contact the housing and serve as a wedge between the cam and the housing and when positioned on the central surface a gap is formed between the rollers and the housing; and a first actuating pin and a second actuating pin mounted on the actuating member and configured to be received within the housing with the first actuating pin positioned between the cam and the first roller and the second actuating pin positioned between the cam and the second roller; such that rotation of the actuating member causes one of the actuating pins to push the respective roller from the side surface towards the central surface against the resilient member. 8. A throttle lever for regulating the throttle of an engine comprising: a non-reaction coupling mechanism for connecting the throttle lever to the throttle, the non-reaction coupling mechanism configured to transmit forces only from the throttle lever to the throttle and to prevent movement of the throttle lever on account of engine vibrations.

9. A throttle lever for regulating the throttle of an engine, the engine comprising an idle mechanism connected to the throttle and configured to move the engine between a low idle mode and a high idle mode in response to the engine load, the throttle lever comprising a non-reaction coupling mechanism for connecting the throttle lever to the idle mechanism, the one way coupling mechanism configured to transmit forces only from the throttle lever to the idle mechanism and to prevent forces from the idle mechanism to be transmitted back to the throttle lever.
10. A throttle lever as claimed in claim 8 or 9 wherein the non-reaction coupling mechanism comprises:
a housing defining an opening to receive a driven shaft;
a cam defining a radial projection positioned within the housing and mounted on the driven shaft; the radial projection comprising a central surface, a first side surface and a second side surface on either side of the central surface, such that the central surface defines a central clearance between the cam and the housing and the first side surface and the second side surface define side clearances between the cam and the housing; the side clearances smaller than the central clearance;
a first roller and a second roller positioned between the radial projection and the housing and having a resilient member in between, the resilient member configured to position the first roller at least partly on the first side surface and the second roller at least partly on the second side surface; the first and second rollers sized such that when partly or completely positioned on the side surface the rollers contact the housing and serve as a wedge between the cam and the housing and when positioned on the central surface a gap is formed between the rollers and the housing; and a first actuating pin and a second actuating pin mounted on the actuating member and configured to be received within the housing with the first actuating pin positioned

between the cam and the first roller and the second actuating pin positioned between the cam and the second roller; such that rotation of the actuating member causes one of the actuating pins to push the respective roller from the side surface towards the central surface against the resilient member.
11. A throttle lever as claimed in claim 8or 9 further comprising a control cable for connecting the idle mechanism to the non-reaction coupling mechanism.
12. A work machine comprising: an engine;
a throttle lever for regulating the throttle of the engine;
a hydraulic circuit powered by the engine;
a sensor to measure the load on the engine by the hydraulic circuit; and
an idle mechanism as claimed in claim 1.
13. An idle mechanism for regulating a throttle of an engine substantially as herein described with reference to and as illustrated in the accompanying drawings.
14. A throttle lever for regulating the throttle of an engine substantially as herein described with reference to and as illustrated in the accompanying drawings.
15. A work machine substantially as herein described.