Title of Invention

THROTTLE OPENING SENSING SYSTEM

Abstract ABSTRACT OF THE INVENTION A throttle opening sensing system for a vehicle with a handlebar comprising a throttle actuator operable by a rotatable throttle control grip and having a cam and follower arrangement, wherein said cam and follower arrangement comprises a cam in the form of a radial recess provided on a throttle pulley, said radial recess on the outer periphery of said throttle pulley being formed by the difference of two unequal predetermined diameters D1 and D2, manual force required to pass the radial recess on rotation of the throttle control grip enabling the rider to sense, by feel, an imminent change of driving mode. 19 MAY 2008
Full Text FORM 2
THE PATENTS ACT, 1970 (39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10, Rule 13)
TITLE
"THROTTLE OPENING SENSING SYSTEM"
APPLICANT
Bajaj Auto Limited, an Indian company, having its registered office at Akurdi,
Pune 411035, Maharashtra, India.
The following specification particularly describes the invention and the manner in which it is to be performed
Original 19 MAY 2008

THROTTLE OPENING SENSING SYSTEM
This invention relates to a throttle opening sensing system for 2 and 3 wheeled vehicles, driven at different speeds and with varying load conditions. This invention particularly is concerned with achieving a feedback by feel of throttle to indicate optimum riding zones to the rider.
At present the operation of the throttle is by a rotating throttle control grip located on right hand side of the handlebar. The grip is rotatable around the sleeve of the handle bar and is connected by a flexible element, such as a pulley and cable or a linkage to the butterfly or slide of the carburetor or a throttle body. When the grip is rotated, the intake air passage in the carburetor opens progressively, to control the quantity of air/fuel mixture going into the cylinder. A 2 or 3 wheeler, powered by an internal combustion engine, uses the throttle as a device to vary inputs of air - fuel to the engine for varying its output power.
There are 4 distinct modes of engine operation. The 1st being Idling, the 2nd is low part throttle openings running on a lean air/fuel mixture (normally up to 40% throttle opening) for good fuel economy, the 3rd is throttle opening which is upwards of 40%, where the air/fuel ratio is progressively richened for good power outputs (but resulting in poor fuel economy) and the 4th is wide open throttle (100% throttle opening, resulting in poor fuel economy) which normally runs on the richest air/fuel mixture and which produces the highest possible output from the engine.
Another parameter which is very important, to optimize the output of an engine, is ignition timing. Based on the combination of the above mentioned modes of engine operation and engine rpm, the best ignition advances are mapped. This results in multiple maps for different conditions of the engine. The number of these maps can vary from a minimum of 2 to as many as desired.
Normally, for the price conscious Indian 2 and 3 wheeler riders, 2 maps
are employed to cover the major conditions as described above. Idling and lean
part throttle conditions of vehicle operation in 1 map (say fuel economy mode)
and the higher throttle openings and wide open throttle conditions (say power
mode) which progressively result in max power output, controlled by the 2nd map.
Various devices are employed to sense the load conditions, which enable the
ignition maps to be suitably switched from 1st to 2nd and vice versa. These

devices could be of contact type (mechanical switch) or non-contact type (magnetic reed type, infra-red sensing type of proximity type switches etc).
Presently, the switching from the 1st to 2nd ignition map and fuel economy mode to power mode or vice versa, is being indicated to the rider by various methods such as, use of visual aids, like coloured telltale bulbs indicating the modes of operation etc. or through an audio signal such as a warning beep.
The inherent flaw in both visual and audio indicating system is that the warning is communicated to the rider after the mode has already changed unintentionally (say from fuel economy mode to power mode). Based on the rider's observations of the this change in mode (which the rider needs to search for) the corrective action of bringing the vehicle back to the previous mode needs some time during which precious fuel is wasted.
There are certain other disadvantages associated with both the above methods. Visual methods-
1. Searching for the visual indications of mode change necessitates diversion of attention of the rider from the road ahead to the instrument console. This compromises the safety of the rider and makes accidents imminent.
2. During riding in bright daylight, it is difficult for the rider to perceive the indication of the visual aids, which defeats the very purpose of its existence.
3. This method employed is prone to failure of the illumination part/parts and mis-representation of the mode.
Audio methods-
1. In noisy city traffic, the audio warning may not be loud enough to attract the attention of the rider.
2. On the other hand, or an absolutely quiet night, the audio warning may sound too loud and irritating.
One of the objectives of the present invention is, therefore, to provide a system in which the rider is pre-warned of the imminent change in driving mode. This system guides the rider, in helping him maintain riding in the fuel economy zone, thus resulting in consistently good fuel economy.


Another objective of the present invention is, to still allow the rider to maintain his concentration on driving, while simultaneously, giving a non-intrusive feedback signal, at the throttle control interface itself. This greatly enhances the safety while driving 2 or 3 wheelers.
Another objective of this invention is to provide a system which is insensitive to the ambient light conditions.
Another objective of this invention is to provide a system, which is mechanically robust and does not include parts like bulbs, which are prone to failure.
Another objective of this invention is to provide a system, in which the rider does not have to dedicate his audio senses to listen for a beep.
Another objective of this invention is to provide a system, which is not irritating to the rider as well as passers-by.
The purpose of the present invention and the endeavor of the application is to indicate, by a change in force required for actuating the throttle, the changeover from one driving mode to another, for example from lean running, part throttle, fuel economy mode a to a richer throttle opening power mode.
With this purpose in view, the present invention provides wherein the throttle actuator includes a mechanical means enabling the vehicle operator to feel a change in manual force required to actuate the throttle and sense an imminent change in driving mode.
In a first embodiment, there is provided a throttle opening sensing system for two and three wheeled vehicles comprising a throttle actuator operable by a rotatable throttle control grip and having a cam and follower arrangement, wherein said cam and follower arrangement comprises a cam in the form of a radial recess provided on a throttle pulley, said radial recess on the outer periphery of said throttle pulley being formed by the difference of two unequal predetermined diameters D1 and D2, manual force required to pass the radial recess discontinuity on actuation of the throttle actuator enabling the rider to sense, by feel, an imminent change of driving mode.
In a second embodiment, there is provided a method of sensing an imminent change in driving mode of a vehicle comprising:
(a) a throttle; and

(b)a throttle actuator actuable by the vehicle operator in response to application of manual force.
wherein change in manual force required to actuate the throttle is felt by the vehicle operator and an imminent change in driving mode indicated.
The throttle opening sensing system and method according to the invention will now be described with reference to the following drawings enclosed with the provisional application.
Figure 1 - shows schematic diagram of the accelerator system of two or three wheeled vehicles with visual signal of the driving mode according to prior art.
Figure 2 - shows schematic diagram of the accelerator system of two or three wheeled vehicles with audio signal of the driving mode according to prior art.
Figure 3 - shows torque diagram of the acceleration system of two or three wheeled vehicles with visual / audio signal of the driving mode according to prior art.
Figures 4A to 4H - show schematic diagrams explaining function of the accelerator system of two or three wheeled vehicles with feedback of the driving mode according to the invention.
Figure 5 - shows force diagram of the accelerator system of two or three wheeled vehicles with feedback of the driving mode according to the invention.
With reference to Figures 1 and 2, the right hand operated throttle control grip (1) is fitted to the throttle pipe (3), which is assembled to the handle bar tube (2) on right-hand side. The throttle pipe is provided with a throttle pulley (6) to which one end of the throttle cable (4) is assembled with the help of cable end (5). The throttle cable (4) has two branch (4a) and (4b), which are used to operate the carburetor (7) and throttle sensor (13) respectively. The throttle sensor (13) is connected to the audio or visual signal as the case may be. Typically, the audio signal aid (10) is in the form of a horn or a speaker and visual aid is in the form of red indicator (14) and green indicator (11). As the engine of the vehicle idles, the said throttle pulley rests against the stopper pulley (21).
When the said throttle control grip is rotated anti-clockwise, looking from the right hand side of the handle bar, the engine RPM increases due to actuation of the carburetor throttle valve. As the predetermined rotation of the said throttle grip is reached (angle A°), the said throttle sensor provides signals to either the

audio or visual signal aid. As the throttle travel reaches in the range of angle B°, the said speaker generates typical noise in case of the audio aid and in case of the said visual aid, the green indicator (11) extinguishes and red indicator (14) gets lighted.
The torque, which is required to rotate the said throttle grip, is uniform through out the travel explained in typical torque vs. opening graph attached as figure 3. The system described above is well known to the public and does not need any detailed explanation.
With reference to Figures 4A to 4H, the improved throttle control system for 2 and 3 wheeled vehicles according to the invention, essentially comprises of right hand operated throttle control grip (1), throttle pipe (3), handle bar tube (2), throttle pulley (20), throttle cable (4) with cable end (5), stopper pulley (21), roller (22), spring (23), lever (24), fulcrum (25), switch (26), housing (27). The assembly of the said throttle control grip (1), throttle pipe (3), handle bar tube (2), throttle pulley (20), throttle cable (4) with cable end (5) and stopper pulley (21) is as in the case of the prior art. The said throttle pulley is provided with radial recess on the outer periphery formed by the difference of two unequal predetermined diameters D1 and D2. The said switch (26) is provided on the housing (27) to enable resting of roller (22) on the said outer periphery of the said throttle pulley, when in operated and keeps it away from the said periphery when not in operation. The said lever is pivoted to the housing and the spring (23) exerts pressure on the said lever.
Alternatively, by redesigning the said spring (23), the said switch (27) can be removed from this system to rest the roller (22) continuously on the said outer periphery of the said throttle pulley (20).
When the engine is idling, the said throttle pulley (20) is resting on the stopper pulley (21). As the accelerator is rotated to increase the engine speed in the direction shown, the said recess starts approaching the said roller. After completion of travel by A0, the roller starts riding on the said recess and the said spring gets compressed to exert pressure on the periphery of the said pulley. This indicates to the driver regarding the change in the mode of the accelerator.
Figure 5 typically illustrates a torque vs. throttle opening diagram as applicable to invented system, where the torque is applied, increases slightly and drops

which provides a feel to the rider that the mode of the operation is getting changed.
The above throttle opening sensing system can be used by connecting the throttle pulley (20) either only to carburetor (not shown) or in conjunction with a device to sense the load conditions which enables mapping of ignition system.
It will be observed with the above explanation that the important function of conveying the change of mode, which is presently done with audio or visual mode, is now possible without their associated drawbacks, by mechanical means as per the invention.
The description given above details a possible mechanical means for conveying the change of mode. However, there are other possibilities of such mechanical systems being employed in the system, which can be worked out with other workshop modifications. It is explicitly understood that such modifications are well within the scope of this invention.

We Claim:
1. A throttle opening sensing system for a vehicle with a handlebar comprising a throttle actuator operable by a rotatable throttle control grip and having a cam and follower arrangement, wherein said cam and follower arrangement comprises a cam in the form of a radial recess provided on a throttle pulley, said radial recess on the outer periphery of said throttle pulley being formed by the difference of two unequal predetermined diameters D1 and D2, manual force required to pass the radial recess on rotation of the throttle control grip enabling the rider to sense, by feel, an imminent change of driving mode.
2. A throttle opening sensing system of claim 1 wherein the change of driving mode is from a lean running part throttle fuel economy mode to a richer throttle opening power mode and vice versa.
3. A throttle opening sensing system for two and three wheeled vehicles as claimed in claim 1 wherein said radial recess is provided on throttle pulley at a predetermined angular position.
4. A throttle opening sensing system for a vehicle with a handlebar comprising:
a throttle control grip assembled to the handlebar for actuating the throttle, a throttle pulley with a cam on circumferential periphery, wherein rotating the throttle control grip from a first angular position to a second angular position causes the operator to encounter a resistive torque opposed to the throttle operating effort enabling the rider to sense, by feel, the change of driving mode.
5. A throttle opening sensing system as claimed in claim 4 wherein said cam has a radial recess.
6. A throttle opening sensing system as claimed in claim 4 or 5 wherein said radial recess corresponds to said first angular position of the throttle.

7. A throttle opening sensing system as claimed in claim 6 wherein said first angular position of the throttle corresponds to a terminal point of a first operating mode of the vehicle power plant.
8. A throttle opening sensing system as claimed in claim 7 wherein the first operating mode is lean operating mode.
9. A throttle opening sensing system as claimed in any one of claims 4 to 8 wherein the second angular position of the throttle corresponds to a second predetermined operating mode of the vehicle power plant.
10. A throttle opening sensing system as claimed in claim 9 wherein the second operating mode is rich operating mode.
11. A throttle opening sensing system in claims 4 to 10 engage-able by a switch.
12. A throttle opening sensing system for sensing an imminent change in driving mode of a vehicle comprising:

(a) a throttle;
(b) a throttle actuator actuabie by the vehicle operator in response to application of manual force wherein the throttle actuator includes a mechanical means enabling the vehicle operator to feel a change in manual force required to actuate the throttle and sense an imminent change in driving mode.
13. A method of sensing an imminent change in driving mode of a vehicle
comprising:
(a) a throttle; and
(b) a throttle actuator actuabie by the vehicle operator in response to application of manual force.
wherein change in manual force required to actuate the throttle is felt by the vehicle operator and an imminent change in driving mode indicated.

14. A throttle opening sensing system for two and three wheeled vehicles substantially as herein described with reference to the drawings.
Dated this 17th day of January 2005
M K CHAKRABARTI of MKC & Associates Applicant's Attorney

Documents:

1102-mum-2003-abstract(19-5-2008).doc

1102-mum-2003-abstract(19-5-2008).pdf

1102-mum-2003-cancelled pages(19-5-2008).pdf

1102-mum-2003-claims(granted)-(17-5-2008).doc

1102-mum-2003-claims(granted)-(17-5-2008).pdf

1102-MUM-2003-CORRESPONDENCE(17-3-2010).pdf

1102-MUM-2003-CORRESPONDENCE(19-2-2010).pdf

1102-mum-2003-correspondence(ipo)-(4-9-2008).pdf

1102-mum-2003-correspondence1(8-8-2006).pdf

1102-mum-2003-correspondence2(19-5-2008).pdf

1102-mum-2003-drawing(17-1-2005).pdf

1102-mum-2003-form 1(10-11-2003).pdf

1102-mum-2003-form 13(19-2-2010).pdf

1102-mum-2003-form 13(19-5-2008).pdf

1102-mum-2003-form 13(2-11-2006).pdf

1102-mum-2003-form 18(10-8-2006).pdf

1102-mum-2003-form 2(granted)-(17-5-2008).doc

1102-mum-2003-form 2(granted)-(17-5-2008).pdf

1102-mum-2003-form 3(16-10-2003).pdf

1102-mum-2003-form 3(19-5-2008).pdf

1102-mum-2003-other document(18-11-2005).pdf

1102-mum-2003-power of attorney(18-4-2006).pdf

1102-mum-2003-power of attorney(9-1-1996).pdf

abstract1.jpg


Patent Number 223577
Indian Patent Application Number 1102/MUM/2003
PG Journal Number 06/2009
Publication Date 06-Feb-2009
Grant Date 15-Sep-2008
Date of Filing 20-Oct-2003
Name of Patentee BAJAJ AUTO LTD.
Applicant Address of Akurdi, Pune-
Inventors:
# Inventor's Name Inventor's Address
1 JOSEPH ABRAHAM of Bajaj Auto Ltd., An Indian company Limited, of Akurdi, Pune-411 035.
PCT International Classification Number F02D 9/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA