ADJUSTABLE STOPPER MECHANISM IN A THROTTLE PULLEY
FIELD OF THE INVENTION
[0001] The present invention relates generally to a throttle pulley and
more particularly, but not exclusively, to an adjustable stopper mechanism in a throttle pulley for an automotive vehicle.
BACKGROUND OF THE INVENTION
[0002] A petrol engine driven three wheeled vehicle is vastly used as a
point to point mode of transportation in rural and urban areas as a passenger carrier, and may also be used solely as a load carrier. The engine is manually operated by a throttle lever connected to a carburettor through a throttle cable. The throttle lever rotates within a predefined range on the handle bar and works via a throttle pulley. Further rotation of throttle lever beyond the predefined range is arrested through a stopper mechanism. Since the maximum speed of such vehicle is low, it is mostly operated at full throttle and consequently, the 'travel' (movement) of throttle cable at the carburettor end is fixed. Due to this reason, the throttle pulley at the handle bar is designed with a fixed stopper.
[0003] However, in a diesel engine driven three wheeled vehicle, the
throttle lever, through the throttle cable, is connected to a governor which limits the speed of the diesel engine by controlling the rate of fuel delivery. The 'travel'

of the throttle cable at the governor end is variable within a pre defined range due to adjustments required in governor on account of emission norms and acceleration requirements. If these variations are not considered, it may lead to lack of throttle opening beyond the fixed travel range due to which peak engine r.p.m may not be achievable and may also lead to throttle cable failure due to excess load on the throttle cable. Hence, a fixed stopper cannot be used in the throttle pulley in the diesel driven three wheeled vehicle and a room for improvement exists.
SUMMARY OF THE INVENTION
[0004] The present subject matter is directed to overcoming one or more
problems as set forth above and thereby to obviate a lacunae in the prior art. It is therefore an object of the present subject matter to ensure a positive stop of the throttle cable by accomodating the maximum and minimum variation at the governor end, and thus preventing excess load to the throttle cable.
[0005] To this end, the present invention relates to an adjustable stopper
member integrated in a throttle pulley and disposed in its rotating direction in a three wheeled vehicle with a diesel type internal combustion engine. The adjustable stopper member is configured to abut at an inner surface of the vehicle handle bar. The throttle pulley is connected to a governor through athroitle cable, and the travel of the throttle cable at the governor end is adjustable between a predefined range.

[0006] The foregoing objectives and summary provide only a brief
introduction to the present subject matter. To fully appreciate these and other objects of the present subject matter as well as the subject matter itself, all of which will become apparent to those skilled in the art, the ensuing detailed description of the subject matter and the claims should be read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The above and other features, aspects and advantages of the subject
matter will be better understood with regard to the following description, appended claims and accompanying drawings where:
FIG. 1 shows a side view of a concerned three wheeled vehicle.
FIG. 2 shows a front view of the anterior portion of the three wheeled vehicle.
FIG. 3 shows a top view of a handle bar assembly of the vehicle.
FIG. 4 shows a front perspective view of a central portion of the handle bar assembly comprising a throttle pulley.
FIG. 5 shows a side view of the throttle pulley when the throttle is in closed condition.
FIG. 6 shows a side view of the throttle pulley when the throttle is in fully open condition.

FIG. 7 shows an exploded view to illustrate the assembly of the throttle pulley with a stopper member.
DETAILED DESCRIPTION OF THE INVENTION
[0008] The subject matter disclosed herein relates to a throttle pulley with
an integrated adjustable stopper member for a three wheeled automotive vehicle which is mainly, but not solely, used as a passenger carrier. It is to be noted that "front" and "rear", and "left" and "right" wherever referred to in the ensuing description, refer to front and rear, and left and right directions as seen in a state of being seated on a seat of the vehicle and looking forward. Furthermore, a longitudinal axis refers to a front to rear axis relative to the vehicle, while a lateral axis refers generally to a side to side, or left to right axis relative to the vehicle. Various other features of the throttle pulley according to the present subject matter here will be discernible from the following further description thereof, set out hereunder.
[0009] FIG. 1 illustrates a side view of a concerned three wheeled
passenger carrier vehicle, referenced by the numeral 100, driven by an internal combustion engine. The three wheeled vehicle can also be used for load carrying applications. It has a front panel 101 supporting a windscreen 102. The lower portion of the front panel 101 is connected to a front wheel 104 with a wheel cover 103 disposed in between. A handle bar 109 is present behind the front panel 101 which is used to operate the vehicle 100. In this view, a steering tube

assembly is not visible to an onlooker of the vehicle. For the purpose of better illustration, the vehicle is laterally divided into two halves, along the line A-A, the front half having the driver's seat 107 while the rear half has a long passenger seat
108 with a seating capacity of minimum three passengers. The rear cabin (also
known as rear compartment) 106 along with the rear half of the vehicle containing
the passenger seat 108 is supported on a pair of rear wheels 105 located on either
side of the longitudinal axis of the vehicle 100. An internal combustion engine
400 is disposed proximately to the passenger seat 108 towards the rear side and is
used to power the vehicle. The engine is a diesel driven internal combustion
engine.
[00010] FIG. 2 illustrates a front view of the three wheeled vehicle with the
panels and styling parts removed. The said three wheeled vehicle 100 is supported on a frame structure spanning from the anterior portion A to the posterior portion P of the vehicle. The frame is connected to a front suspension 203 and a trailing arm 204. A steering column assembly is connected to the front wheel 104 and comprises of a steering column tube 202, rotatably supporting the front wheel 104 and acting as a mechanical link between the handle bar 109 and the front wheel 104. The steering column tube 202 is engulfed by a head tube 205 on all sides and welded or secured to the head tube. The head tube 205, which is a part of vehicle chassis, usually houses bearings that allow the steering tube 202 to turn freely. A clutch actuation lever 111 is pivotally mounted at a distal end of the handle bar
109 preferably on the left side thereof, such that the user may grip the handle bar

109 to change the gear ratio by retracting and releasing the clutch actuation lever 111.
[00011] The said vehicle is operated and steered through the handlebar 109.
FIG. 3 shows a top view of the handle bar assembly. The engine is manually operated by a throttle grip 112 pivotally mounted at a distal end of the handle bar 109 preferably on the right side thereof. The throttle grip 112 is rotated by the vehicle driver to turn a throttle pulley 120 from its default position. The throttle pulley in turn operates a throttle cable (not shown) which is connected to a fuel supply unit like a governor at one end. This end will henceforth be called as the 'governor end'. At the other end, the throttle cable is rotatably connected to the throttle pulley 120 and this end will be called as the 'pulley end'. In an embodiment, the governor is of speed limiting type which limits the speed of the diesel engine by controlling the rate of fuel delivery. The throttle pulley 120 is thus connected to the governor through the throttle cable.
[00012] The travel of the throttle cable at the governor end varies between a
maximum and minimum range due to variations and adjustments in governor. This range is predetermined. If the variation in travel of the throttle cable is not accommodated at the pulley end, then it may lead to lack of further throttle opening where the peak engine r.p.m is not achieved. If the throttle pulley is rotated by the driver beyond the required angle of rotation needed for cable travel at the governor end, it will put undesirable excess load on the throttle cable which may fail. The throttle pulley 120 is thus configured to 'adjust' the travel of the

throttle cable at the governor end between the predefined range and also to prevent excessive and instant loads on the throttle cable.
[00013] The throttle pulley according to the present subject matter is now
explained in detail with the help of FIGS. 4 to 7. In an embodiment, the throttle pulley is housed in a central portion 114 of the handle bar 109. The central portion 114 is covered and the throttle pulley is not visible to the vehicle driver. FIG. 4 shows a front perspective view of the central portion 114. The central portion 114 houses the throttle pulley 120 as well as a gear pulley 130 adjacent to each other. By convention, the throttle pulley 120 is located on the right side in the central portion 114 of the handlebar. The gear pulley controlling the gearing operation is located in the left side of the central portion 114.
[00014] The throttle pulley 120 is disposed on a throttle tube 113 (FIG. 7).
A hairpin shaped clip pin 122 passing radially through the throttle pulley 120 and the throttle tube 113 holds the throttle pulley 120 over the throttle tube 113.
[00015] According to an embodiment, the throttle pulley 120 comprises of
an adjustable stopper member 124 configured to abut an inner surface 115 of the
handle bar 109. In this way, the adjustable stopper member 124 arrests the turning
of the throttle pulley 120 beyond a particular point and ensures a positive stop for
the throttle cable (no excess cable travel than required) by accommodating the
maximum and minimum variation in the throttle cable at the governor end
[00016] As shown in FIG. 4 and FIG. 5, the throttle pulley 120 further
comprises of a circular portion 128, an arc shaped portion 127 radially projecting

out from the circular portion 128 and an enmoulded projection 123 attached with the arc shaped portion 127. The arc shaped portion 127 only partially covers the circumference of the circular portion 128 of the throttle pulley 120. The central portion 128, the arc shaped portion 127 and the enmoulded projection 123 are all formed integral as one part so as to reduce the steps of manufacture of the throttle pulley. However, in a different embodiment, they can be formed separately and operatively connected to each other to develop into a functional throttle pulley. Further, a throttle cable guide 121 is provided between the surfaces of the arc shaped portion 127 within which the throttle cable is disposed and held. The throttle cable guide, 121 enables the rotatory motion of the throttle cable 120 around the throttle pulley 120. One end of the throttle cable is fixed in the throttle cable guide 121 through a throttle cable bullet groove 126.
[00017] According to an aspect, the stopper member 124 is operatively
engaged with the enmoulded projection 123 of the throttle pulley 120 and configured to abut at the inner surface 115 of the central portion 114. For this purpose, the enmoulded portion 123 is provided with a receiving opening. The inner radial surface of receiving opening comprises of a threaded insert 123a. The adjustable stopper member 124 is received into this threaded insert which will hold the stopper member from unsecuring. It is to be noted that the stopper member 124 is rotatable, to and fro, in the threaded insert 123a of the enmoulded projection 123 so that it abuts the inner surface 115.
[00018] In a preferred embodiment, the stopper member 124 is a threaded
bolt. The stopper member is held into its position by a lock nut 125 which is

threadably engaged with the stopper member 124. Thus, the distance between a portion of the stopper member 124 abutting the inner surface 115, and the inner surface 115 of the central portion 114 can be varied by rotating the stopper member 124 in the insert 123a and then maintaining it in that position through the lock nut 125. Thus, the distance between the stopper member 124 and the inner surface 115 can be increased or decreased depending upon on the predefined range of the travel required by the throttle cable at the governor end.
[00019] The function of the throttle pulley 120 comprising the adjustable
stopper member 124 will now be described. FIG. 5 shows the left side view of the throttle pulley in its default (inoperative) position. The enmoulded projection is towards the forward direction of the handle bar and there is a substantial distance between the stopper member 124 and the inner surface 115 of the central portion 114. FIG. 6 shows a left side sectional view of the throttle pulley when it is operated in the clock wise direction (as shown by the arrow) by the vehicle driver (operative position). The rotation of the throttle pulley 120 is restricted in the clockwise direction by the stopper member 124 and in the anti-clockwise direction by the arc shaped portion 127. The clockwise direction would be when the vehicle operator pulls the throttle grip 112 towards himself and the anti¬clockwise direction would be when the vehicle operator releases the throttle grip 112 to return to the inoperative position. In the neutral position, the arc shaped portion 127 of the throttle pulley butts against the corresponding portion provided from the throttle tube 113. When the vehicle operator rotates the throttle grip 112 to open the throttle, the throttle tube 113 rotates due to which the throttle pulley

120 rotates. The throttle pulley 120 may rotate about a certain angle to achieve full throttle condition. Since the maximum speed of the vehicle is low, the operator usually operates the vehicle at full throttle. After the full throttle condition is achieved, the throttle pulley 120 does not rotate further as its rotation is arrested by the stopper member 124. The stopper member 124 butts against the inner surface 115 of the central portion 114 preventing further rotation. The stopper member 124 can move forward and backward in the insert 123a by loosening the lock nut 125 and rotating the stopper member 124. Hence the butting of stopper member on the inner surface 115 of the central portion 114, and consequently the distance between the stopper member and the inner surface is adjustable.
[00020] Any adjustment in the stopper member reflects in the travel of the
throttle cable at the governor end. The stopper member 124 may be loosened or tightened according to the requirement of the governor thus allowing the throttle cable travel at the governor end to vary within the predetermined range. This travel is variable within the range of a maximum value and a minimum value depending upon governor settings. If the stopper member is tightened, butting with the inner surface takes place later thus allowing additional rotation of throttle cable. On the other hand, if the stopper member is loosened, butting will take place faster thus cutting short the rotation of throttle cable. Contrastingly, in a fixed stopper throttle pulley, the distance between the stopper member and the inner surface is not adjustable. Hence the travel of throttle cable at the governor

end in not variable and has a fixed value. This may limit the acceleration at the governor end and may also limit the engine operation below the peak rpm.
[00021] The present subject matter and its equivalent thereof offer many
advantages, including those which have been described henceforth. The adjustable stopper mechanism in the throttle pulley assures a positive stop by accommodating the maximum and minimum variation in the travel of the throttle cable at the governor end. This eliminates any excess and instant load on the throttle cable thereby preventing its failure. The stopper member erases any excess play in the throttle cable after complete adjustment of the throttle cable slack at the governor end. Further, the adjustment can be done simply by turning the stopper member thus making the adjustment simple and easy.
[00022] The present subject matter is thus described. The description is not
intended to be exhaustive nor is it intended to limit the invention to the precise form disclosed. It will be apparent to those skilled in the art that the disclosed embodiments may be modified in light of the above description. The embodiments described are chosen to provide an illustration of principles of the invention and its practical application to enable thereby one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Therefore the forgoing description is to be considered exemplary, rather than limiting, and the true scope of the invention is that described in the appended claims.

We claim:
1. A manually operated rotatable throttle pulley 120, mounted on a handle
bar 109 of a three wheeled vehicle 100 with a diesel type internal
combustion engine, comprising:
an adjustable stopper member 124 configured to abut at an inner surface 115 of the handle bar 109;
wherein the throttle pulley 120 is connected to a governor through a throttle cable, and wherein further, the travel of the throttle cable at the governor end is adjustable between a predefined range.
2. The throttle pulley as claimed in claim 1, wherein the stopper member 124 is operatively engaged with an enmoulded projection 123 of the throttle pulley 120.
3. The throttle pulley as claimed in claim 2, wherein the throttle pulley 120 also comprises:
a circular portion 128,
an arc shaped portion 127 radially projecting out from the circular portion 128,
wherein the enmoulded projection 123 is attached with the arc shaped portion 127 and has a threaded metal insert 123a receiving the -• stopper member 124.

4. The throttle pulley as claimed in claim 1, wherein the stopper member 124 is a threaded bolt.
5. The throttle pulley as claimed in claim 4, wherein a lock nut 125 is threadably engaged with the stopper member 124.
6. The throttle pulley as claimed in claim 1, wherein the throttle pulley 120 is housed in a central portion 114 of the handle bar 109.
7. The throttle pulley as claimed in claim 1, wherein the stopper member 124 erases excess play in the throttle cable after adjustment of the throttle cable slack at the governor end.
8. A manually operated rotatable throttle pulley 120, housed in a central portion 114 of a handle bar 109 of a three wheeled vehicle 100 with a diesel type internal combustion engine, comprising:
a circular portion 128,
an arc shaped portion 127 radially projecting out from the circular portion 128,
an enmoulded projection 123 attached with the arc shaped portion 127,
an adjustable stopper member 124 operatively engaged with the enmoulded projection 123-and configured to abut at an inner surface 115-of the central portion 114;

wherein the throttle pulley 120 is connected to a governor through a throttle cable,
and wherein further, the travel of the throttle cable at the governor end is alterable between a predefined range.
9. The throttle pulley as claimed in claim 8, wherein the stopper member 124 is a threaded bolt.
10. The throttle pulley as claimed in claim 9, wherein a lock nut 125 is threadably engaged with the stopper member 124.