FIELD OF INVENTION
The present invention relates to throttle control mechanism for automotivcs. In particular, the present invention relates to throttle position detecting apparatus constructed within switch console of a handle bar assembly of two-wheeler, three-wheeler, and similar vehicles.
BACKGROUND
A throttle position detecting apparatus in two-wheeler/three-wheeler and similar vehicles is structured such that it detects the rotation of a throttle grip mounted on a handle bar and converts the same into electrical signals. The signals are then transmitted to an Electronic Control Unit (ECU). Based on the received signals, ECU controls the engine functions such as air-fuel ratio correction, power increase/decrease, fuel cut-off control and engine modes (idle, part throttle and Wide Open Throttle) etc.
Throttle position detecting device having various configurations have been proposed conventionally, one example of which is one disclosed in JP-A-2004-254278. The throttle position detecting device disclosed in this document is mainly composed of a drive pulley that rotates in conjunction with a throttle grip, a detection gear that is in mesh with a gear that is part of the drive pulley, and a throttle position sensor that is a potentiometer and detects a rotation angle of the detection gear. When the throttle grip is rotated, the indication value of the potentiometer is varied via the drive pulley and a throttle position is thereby detected.
However, in the above conventional throttle position detecting device, the drive pulley, the detection gear, and the throttle position sensor are separate bodies and are provided in cases individually. This may cause a large assembling error which makes it difficult to detect correct throttle position, thereby lowering the reliability of the device. Also, such individually placed bodies are not suitable for lower end vehicles due to complex designs and high manufacturing cost.
Figure 3 shows a flow diagram illustrating functioning of another conventional throttle position detection assembly. The earlier mechanism consisted of a handle bar switch console 301. a seperate junction box 302 and a throttle position detecting apparatus 303 along with a Capacitor

Discharge Ignition (CDI) unit 304. From a handle bar switch console 301, the throttle cable goes to a carburator 305 for application 306 after passing through junction box 302. A fuel tank 307 is connected to the carburator 305. The throttle position detecting apparatus 303 is connected to junction box 302 for sending further signal to CDI unit 304 for final application 308. Such handle bar assembly employs a throttle as shown in Figures 2 and 3. However, this assembly occupies more space due to separate junction box and throttle position detecting apparatus and hence, is not suitable for lower end vehicles.
Few more examples of conventional throttle position detecting apparatus include US 7.010.955 and US 6,576,890. These apparatus disclosed in these documents employ Hall Effect sensors. However, devices with Hall Effect sensors produce a very low signal level and thus require current conditioning through ECU. Due to these reasons, the sensors are also not suitable for lower end vehicles.
Therefore there is a need for low cost, simple design throttle position detecting apparatus that works efficiently for low end vehicles.
OBJECT OF THE INVENTION
The main objective of the present invention is to provide low cost throttle position detecting apparatus on the handle bar of the two wheelers/ three wheelers and similar vehicles.
Another objective of the present invention is to provide a throttle position detecting apparatus as a part of handle bar switch console, thereby eliminating an additional component.
Yet another objective of the present invention is to control the position of butterfly valve through ECU to achieve an enriched air-fuel ratio in an internal combustion engine by simple and reliable design with reduced number of parts.
SUMMARY OF THE INVENTION
A throttle position detecting device for a vehicle comprising a rotatable throttle grip mounted on a leading end of a handle bar, said throttle grip including an end portion having a cam; a plunger disposed below and in contact with the cam for exhibiting linear motion in response to rotary

motion of the throttle grip; a moving contact provided on an external surface of the plunger: and a casing for covering the end portion of the throttle grip having the cam and the plunger, an inner surface of the casing being provided with at least two fixed contacts such that the moving contact provided on the external surface of the plunger makes or breaks contact therewith on rotation of the throttle grip.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention are set forth with particularity in the appended claims. The invention itself, together with further features and attended advantages, will become apparent from consideration of the following detailed description, taken in conjunction with the accompanying drawings. One or more aspects of the present invention are now described, by way of example only, with reference to the accompanied drawings wherein like reference numerals represent like elements and in which:
Figure 1 illustrates perspective view of right hand side handle bar switch console with throttle grip for two wheeler/three wheeler vehicles.
Figure 2A illustrates a conventional throttle grip for two/three wheeler vehicles.
Figure 2B illustrates a sectional view of conventional throttle grip for two/three wheeler vehicles.
Figure 3 illustrates a flow diagram illustrating functioning of the conventional throttle position detecting apparatus in vehicles.
Figure 4 illustrates a flow diagram illustrating functioning of the throttle position detecting apparatus in accordance with an aspect of the present invention.
Figure 5 illustrates a sectional view of throttle position detecting apparatus mounted on right hand side switch console of 2-wheeler/3-wheeler in accordance with an aspect of the present invention.
Figure 6 illustrates exploded view of throttle position detecting apparatus mounted on right hand side switch console of 2-wheeler/3wheeler in accordance with an aspect of the present invention.

Figure 7 illustrates the sectional view of the throttle position detecting apparatus in accordance with an aspect of the present invention.
Figure 7A illustrates the sectional view of the throttle position detecting apparatus at initial condition in accordance with an aspect of the present invention.
Figure 7B illustrates the sectional view of the throttle position detecting apparatus at cut-off condition in accordance with an aspect of the present invention.
Figure 8A illustrates a perspective view of the throttle grip according to one aspect of the present invention.
Figure 8B illustrates a sectional view of the throttle grip according to one aspect of the present invention.
Figures 9A and 9B illustrate a front view and a rear view of the plunger in accordance with an aspect of the present invention.
Figure 10 illustrates a sectional view of a casing showing fixed contact in accordance with an aspect of the present Invention.
DETAILED DESCRIPTION
While the invention is susceptible to various modifications and alternative forms, specific aspects thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternative falling within the spirit and the scope of the invention as defined by the appended claims.
Before describing the aspects in details, it may be observed that the novelty and inventive step that are in accordance with the present invention reside in the throttle position detecting apparatus constructed within switch console of a handle bar assembly of vehicles, accordingly. the drawings are showing only those specific details that are pertinent to understanding the

aspects of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.
The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device that comprises a list of components docs not include only those components but may include other components not expressly listed or inherent to such setup or device. In other words, one or more elements in a system or apparatus proceeded by "comprises... a" does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.
The present invention relates to throttle control mechanism for automotives. In particular, the present invention relates to throttle position detecting apparatus constructed within switch console of a handle bar assembly of two-wheeler, three-wheeler, and similar vehicles.
Accordingly, the present invention relates to a throttle position detecting device for a vehicle comprising a rotatable throttle grip mounted on a leading end of a handle bar, said throttle grip including an end portion having a cam; a plunger disposed below and in contact with the cam for exhibiting linear motion in response to rotary motion of the throttle grip; a moving contact provided on an external surface of the plunger; and a casing for covering the end portion of the throttle grip having the cam and the plunger, an inner surface of the casing being provided with at least two fixed contacts such that the moving contact provided on the external surface of the plunger makes or breaks contact therewith on rotation of the throttle grip.
In an aspect of the present invention, the casing comprises of two half-divided sub-casing being respectively mounted onto the handlebar from an upper and a lower directions to hold at least the cam of the throttle grip there between.
In another aspect of the present invention, the casing further comprises a first spring disposed below the plunger for resilient vertical movement of the plunger on rotation of the throttle grip.

In yet another aspect of the present invention, the plunger is provided with a second spring disposed at the rear end of the moving contact for resilient horizontal movement of the moving contact.
In still another aspect of the present invention, the plunger is provided with a locking arrangement to prevent the plunger from exiting the casing.
In another aspect of the present invention, the plunger is provided with cut out windows on the sides to prevent the housed moving contact from exiting the plunger.
Figure 4 shows a block diagram illustrating functioning of the throttle position detection assembly in accordance with an aspect of the present invention.
According to the present invention, the need for the separate junction box 302 and the throttle position detection apparatus 303 can be eliminated from the assembly. The handlebar switch console 401 includes the throttle position detecting apparatus 303 which has been designed for the two modes, economy (OFF) mode and power (ON) mode. At throttle released/initial condition, signal will be high (ON) which gives the power mode signal to Capacitor Discharge Ignition (CDI) and after cut-off angle, signal will be low (OFF) which gives the economy mode signal to CDI for further engine control. Hence, the throttle position signals can be achieved from handlebar switch console 401 itself thereby reducing the overall cost of the system.
Figure 5 illustrates a sectional view of throttle position detecting apparatus mounted on right hand side switch console of two-wheeler/three-wheeler in accordance with an aspect of the present invention.
The throttle position detecting apparatus 500 is a simple make and break mechanism designed as a low cost throttle position controlling device. According to an aspect of the present invention, the apparatus comprises of a casing, a throttle grip 501, a plunger 502 and atleast two fixed contacts 503. The casing is mounted onto a handle bar of a vehicle. The throttle grip 501 is disposed in proximity of the casing 500 and on leading end of the handle bar such that the throttle grip 501 is rotatable with respect to the handle bar. An end portion of the throttle grip 501 is provided with a cam. Below the cam of the throttle grip 501, the plunger 502 is disposed.

The casing consists of two-half divided sub-casing i.e. upper sub-casing 504a and lower sub-casing 504b (hereinafter collectively referred to as casing 504) which are respectively mounted onto the handle bar from an upper and a lower directions so as to hold the end portion of the throttle grip 501 having the cam there between. The lower sub-casing 504b accommodates the plunger 502. The plunger 502 acting as a cam follower is in contact with the cam of the throttle grip 501 and exhibits vertical motion on rotation of the throttle grip 501. The plunger 502 rests against a first spring 505 so that plunger 502 can travel up/down within the casing 504 as the throttle grip rotates. A moving contact 506 is connected to an outer surface of the plunger 502. Further, a pair of fixed contacts 503 is insert molded inside the casing 504 such that the moving contact 506 provided on the external surface of the plunger 502 makes/breaks contact with the fixed contacts 503 on rotation of the throttle grip 501. A second spring 507 is placed behind the moving contact 506 for resilient horizonal movement of the moving contact 506 and for having contact pressure over fixed contacts 503 incessantly.
Initially, the moving contact 506 remains in contact with the fixed contacts 505. During rotation of throttle grip 501, the plunger 502 follows the cam path and gets pressed down inside the casing against the spring 505, while breaking continuity of the moving contacts 506 with the fixed contacts 503 at a certain defined angle of rotation of throttle grip. The initial normally closed condition will be changed to normally open condition after pre-defined angle of rotation of the throttle grip. Accordingly, the signal will go to CDI unit 307 and GDI unit will confirm the economy /power mode curves for engine.
Figure 6 illustrates an exploded view of throttle position detecting apparatus shown in Figure 5.
Figure 7 illustrates the sectional view of the throttle position detecting apparatus in accordance with an aspect of the present invention.
The side sectional view of the throttle position detecting apparatus is shown in assembled condition. The plunger 502 always remains in contact with the cam of the throttle grip 501 and acquires a vertical movement on rotation of the throttle grip 501.

Figure 7A illustrates the sectional view of the throttle position detecting apparatus at initial condition in accordance with an aspect of the present invention.
As shown, at the initial stage, the throttle grip 501 is in released condition and hence contact will be Normally Closed (NC). In normally closed condition, the plunger 502 is in released condition and hence is in contact with lowest point (starting point) of the cam. The moving contact 506 housed inside the plunger 502 engages with the fixed contact 503 and the continuity is maintained. At this time, the angle between the center of axis of the throttle and the throttle cable end holding point is 46.5 degrees. This angle can vary upon the initial setting of throttle in free position.
Figure 7B illustrates the sectional view of the throttle position detecting apparatus at cut-off condition in accordance with an aspect of the present invention.
As the throttle grip 501 is rotated, the plunger 502 follows the cam path over throttle grip 501 and moves downward continuing the engagement of the moving contact 506 with the fixed contacts 503. At a pre-defined angle of rotation of throttle grip 501 for which cam has been designed, the plunger 502 comes in contact with the peak point of cam (finishing point) leading to break in the continuity of the moving contact 506 with the fixed contacts 503. After this angle. the plunger 502 will be in pressed condition and contact will be Normally Open (NO). In normally open condition, the moving contact 506 is not in contact with the fixed contacts 503. The angle for cut-off can vary upon the requirement. In one embodiment, the angle for cut-off is 49.1 degrees.
Figure 8A and 8B illustrates a perspective and a sectional view respectively of the throttle grip according to one aspect of the present invention.
The throttle grip 501 in the present invention is provided with a cam. The cam is placed on left end over the radial surface of the throttle grip 501. The cam has been designed according to desired cut-off angle of the rotation of the throttle grip 501 and calculated depth up to which the plunger 502 will be pressed during operation to break the continuity. Alternately, the make and break mechanism could be interchanged according to requirement. In an exemplary aspect of the present invention, the position of the fixed contacts 503 can be changed by placing the fixed

contacts 503 at a defined depth at which there will be no contact between the moving contact 506 and fixed contacts 503 at throttle released condition and hence the condition will be Normally Open (NO). The plunger 502 will come in contact with fixed contacts 503 only after getting pressed downward to make continuity. This condition is referred to as Normally Closed (NC) condition.
Figures 9A and 9B illustrate a front view and a rear view of the plunger in accordance with an aspect of the present invention.
The plunger 502 is designed in a manner to work for carrier purpose as well as plunger purpose. The upper part of the plunger 502 acts as a cam follower for the cam over the throttle grip during operation. The lower part of the plunger 502 is designed to accommodate the moving contact 506 and the second spring 507 behind the moving contact 506 for constant contact pressure over the fixed contacts 503. The second spring 507 creates contact pressure over moving contact 506 and against fixed contacts 503 that is insert molded within the casing 504. Cut out windows arc provided on the sides of plunger 502 to prevent the moving contact 506 from coming out and from moving within the plunger 502. The first spring 505 is located inside the casing 504 just below plunger 502 and the plunger 502 glides against spring pressure and throttle pressure inside the casing 504. This plunger 502 travels a linear distance downwards against the first spring 505 within the casing. At the rear side of the plunger/carrier 502, there is a locking arrangement 901 which prevents the moving contact 506 from exiting the casing 504 during operation.
Figure 10 illustrates a sectional view of lower sub-casing showing fixed contact in accordance with an aspect of the present invention.
The lower sub-casing 504 houses the plunger 502 and a portion of the cam of the throttle grip 501 along with wiring harness. The two fixed contacts 503 are insert molded with wall of the casing 504. The casing 504 includes a guide rail provided inside a pocket at throttle movement area for smooth floating of plunger 502 against spring force. A round peep is also provided in the casing 504 for guiding and locating spring responsible for resilient movement of the plunger 502.

Drain holes are provided at the lower end of the plunger 502 to prevent accumulation of water, dust or other contamination in the said casing 504.
While the particular preferred embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the teachings of the invention. It is therefore contemplates that the present invention cover any and all modifications, variations or equivalents that fall within the scope of the basic underlying principles disclosed above and claimed herein.
ADVANTAGES OF THE PRESENT INVENTION
The present invention has the following advantages:
1. The throttle position detecting apparatus of the present invention involves reduced number of parts.
2. The throttle position detecting apparatus of the present invention has simple and reliable design effective.
3. The throttle position detecting apparatus of the present invention is cost effective and hence, suitable for lower end vehicles.

We Claim:
1. A throttle position detecting device for a vehicle comprising:
a rotatable throttle grip mounted on a leading end of a handle bar, said throttle grip including an end portion having a cam;
a plunger disposed below and in contact with the cam for exhibiting linear motion in response to rotary motion of the throttle grip;
a moving contact provided on an external surface of the plunger; and a casing for covering the end portion of the throttle grip having the cam and the plunger, an inner surface of the said casing being provided with at least two fixed contacts such that the moving contact provided on the external surface of the plunger makes or breaks contact therewith.
2. The device as claimed in claim 1, wherein the casing comprises of two half-divided sub-
casing being respectively mounted onto the handlebar from an upper and a lower directions
to hold at least the cam of the throttle grip there between.
3. The device as claimed in claim 1, wherein the casing further comprises a first spring
disposed below the plunger for resilient vertical movement of the plunger on rotation of the
throttle grip.
4. The device as claimed in claim 1, wherein the plunger is provided with a second spring disposed at the rear end of the moving contact for resilient horizontal movement of the moving contact.
5. The device as claimed in claim 1, wherein the plunger is provided with a locking arrangement to prevent the plunger from exiting the casing.
6. The device as claimed in claim 1, wherein the plunger is provided with cut out windows on the sides to prevent the housed moving contact from exiting the plunger.

7. A throttle position detecting device for a vehicle substantially as herein described with reference to the accompanying drawings.