FORM-2
THE PATENTS ACT, 1970
The Patents Rules, 2003
COMPLETE SPECIFICATION (SECTION 10 and RULE 13)

TITLE

A CHOKE CONTROL DEVICE
APPLICANT
We, Bajaj Auto Limited, an Indian Company, having its principal place of business at Akurdi, Pune - 411 035, State of Maharashtra, India, an Indian Company.
The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed:-

This invention relates to choke control device for vehicles using handle bar as steering control.
BACKGROUND:
It is a known fact that a vehicle running on an internal combustion engine with a carburetor faces difficulty in starting particularly in cold ambient conditions. In such conditions, the engine requires an additional supply of fuel to facilitate ignition of the air fuel mixture supplied into the engine. Normally, an additional supply of fuel is given from the carburetor through a fuel enriching means such as opening a spring loaded plunger valve, conventionally called a choke, provided in the carburetor. This is operated by a device, conventionally called a choke control device, which is disposed at a convenient location to facilitate easy operation by the vehicle operator. For example, in some types of motorcycles or scooters, the choke control device, operable by a simple lever, is provided on the carburetor body below the petrol tank. In some other types of motorcycles or scooters, the choke control device may be provided conveniently on the handle bar; usually near the switches or may be provided at a location below the rider seat.
In some two or three wheel vehicles, the choke control device may be disposed proximate to the switch control housing on the handle bar of the vehicle. Alternately, the choke control may be provided on the floor panel, particularly on some models of three wheelers. The choke control arrangements explained above may be of lockable type which require manual effort or non-lockable type, which automatically retract after release. These types of arrangements are well known and do not need detailed explanation. The vehicle may be equipped with an electric starter.
The switch control housing on the handle bar may comprise switches for various vehicle controls like the horn, the turn signal indicators, the head lamp etc. One of the difficulties in some of the known systems of the choke control device disposed near the switch control housing of handle bar is the inconvenience that the rider experiences in accessing the choke control. Further, it is the applicant's view that such a location on the instrument console of a vehicle is more important for
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mounting of other control devices of the vehicle such as lighting, horn etc., owing to more frequent usage of such controls than a choke. The mounting of the choke operating mechanism in such a location compromises on available space for such important controls. Therefore, a vehicle designer has to provide a suitable location for mounting of choke control device that is convenient to operate and that does not compromise on the available space on the instrument console. The other locations of the choke control device, such as the floor panel or the carburetor body below the petrol tank, may pose inconvenience to the rider, in that he has to bend forwards to access the device.
In lockable choke arrangement, the choke device can be locked in a position that would supply a richer air fuel mixture to the engine for ease of start, and subsequently unlocked by the rider after engine is started. In such types of arrangement, there is a possibility that the rider may forget to unlock the choke control device after engine is started. This is particularly severe as there is no visual indication to the rider to highlight an "ON" position of the choke when the vehicle is running. Prolonged riding of a vehicle on choke, may lead to significantly increased fuel consumption, poor driveability, higher emissions and possible damage to the engine. The vehicle may stall while riding, which poses a safety issue.
STATEMENT OF INVENTION:
The applicants have invented an arrangement of the choke control device that would avoid the above stated problems.
According to the invention there is provided a choke control device for a vehicle with a handle bar as steering control, comprising a push pull type mechanism, having a handle which moves along an axis wherein the axis of the push pull handle is transverse to the axis of the vehicle;
Preferably, when in the "ON" position, the handle of the push pull mechanism is highly visible to the operator when seated in the riding position;
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Preferably, a part of the push pull mechanism, not normally visible when in the "OFF" position, becomes highly visible to the operator when in the "ON" position;
Preferably, the visibility of such part is enhanced by the use of bright colours;
Preferably, the push pull mechanism may be locked in "ON" position;
Preferably, the push pull mechanism is located at a distal end of a handle bar of a vehicle;
Preferably, mechanism is housed within the end of the handlebar;
Preferably, the mechanism is housed on the side opposite to the throttle control;
Preferably, the push pull mechanism activates a choke;
Preferably, the device requires manual effort for switching between ON and OFF position.
Preferably, the air fuel mixing device is a carburetor.
Objectives:
One of the objectives of the present invention is to provide a choke control device, which is convenient to operate.
Another objective of the invention is to provide a visual indication on the position of the choke control device.
DETAILED DESCRIPTION OF INVENTION
The following is a detailed description of the invention with reference to following accompanying drawings:
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Figure l illustrates a choke control device, according to an embodiment of the invention and disposed inside the right hand side handle bar tube.
Figure 2 illustrates a detailed view of choke control device mentioned above.
Figure 3 illustrates a choke control device, according to an embodiment of the invention and disposed inside the left hand side handle bar tube.
Figure 4 illustrates a detailed view of choke control device mentioned in figure 3.
According to one embodiment of the invention illustrated in figures 1 and 2, the said operating means essentially comprises a handle bar (1) with a handle bar tube right side (la), a sleeve (15), a choke knob (2), a choke rod (3) of section having at least one flat surface and provided with serration (10) on such flat surface substantially along its operative length, a cap (14), a bush (16) with central hole (12) and a tubular portion (7), a fastening means (13), a ring (5), outer cable (8), inner cable (9), cable end (6); the holding means comprises a ball (4) and a spring (11). The handle bar (1) and the tube (la) are integral (the tube may be die cast with handlebar) and the throttle grip (lb) is assembled on the said tube (la) with a sleeve (15) as known. The said choke knob (2) is either molded with or rigidly fixed to one end of choke rod (3), which passes through a hole (12) and a tubular portion (7) provided centrally in the said bush (16). The other end of the said choke rod (3) is connected to one end of said inner cable (9) by crimping of said ring (5). The other end (6) of said inner cable (9) is connected to said fuel enriching means such as carburetor plunger (not shown) in a known manner. The said cap (14) is assembled inside tube (la) with holding means such as a ball (4) and a spring (11) which maintains a constant pressure on said ball (4) to rest on serration (10) provided on said choke rod (3) to retain position of choke rod (3).
According to the other embodiment of the invention illustrated in figure 3 and 4, the said operating means essentially comprises a handle bar (1) with a handle bar tube left side (la), a choke knob (2), a choke rod (3) of section having at least one flat
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surface and provided with serration (10) on such flat surface substantially along its operative length, a cap (14), a bush (16) with central hole (12) and a tubular portion (7), a fastening means (13), a ring (5), outer cable (8), inner cable (9), cable end (6); the holding means comprises a ball (4) and a spring (11). The handle bar (1) and the tube (la) are integral (the tube may be die cast with handlebar) and the throttle grip (lb) is assembled on the said tube (la) as known. The said choke knob (2) is either molded with or rigidly fixed to one end of choke rod (3), which passes through a hole (12) and a tubular portion (7) provided centrally in the said bush (16). The other end of the said choke rod (3) is connected to one end of said inner cable (9) by crimping of said ring (5). The other end (6) of said inner cable (9) is connected to said fuel enriching means such as carburetor plunger (not shown) in a known manner. The said cap (14) is assembled inside tube (la) with holding means such as a ball (4) and a spring (11) which maintains a constant pressure on said ball (4) to rest on serration (10) provided on said choke rod (3) to retain position of choke rod (3).
During starting of the engine of the vehicle in cold ambient conditions, the said fuel enrichment device such as a plunger valve (not shown) in the carburetor (not shown) is allowed to supply additional fuel in the air from the carburetor to engine by pulling the choke knob (2) outward of handle bar by the rider of the vehicle. The choke rod (3) gets pulled which in turn pulls the inner cable (9) enabling actuation of the fuel enrichment device such as carburetor plunger valve to allow increased quantity of fuel in the air from the carburetor to the engine of the vehicle and facilitate starting. The ball (4) gets locked in one of the corresponding serrations (10) which would prevent any further linear movement of choke rod due to spring pressure exerted on ball. The choke control device is visibly apparent to the rider in its operating position. After starting the engine, the choke knob (2) is pushed towards inwardly of the handle bar by the rider of the vehicle. The fuel enrichment device, such as the plunger valve closes and shuts off the increased supply of fuel in the air fuel mixture from the carburetor to the engine. The carburetor and fuel enrichment device such as spring loaded plunger valve and choke cable and other conventional details of handle bar have not been illustrated and described as such details are not necessary for understanding of the invention.
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The choke control device according to the present invention is prominently visible to the rider in its operating position, as it protrudes out of the end of the handle bar. This serves a visual control to the rider to prevent prolonged riding with the choke on, thereby avoiding high fuel consumption, poor driveability and higher emissions.
The invention advantageously includes the locking arrangement as described above to ensure that the choke operates for the requisite time to enable the engine to start.
The choke control device according to the invention is simple in construction. It is not prone to failure and wear and tear, is very reliable and does not require frequent maintenance.
The choke knob, choke rod and its locking arrangement may be of other profile or geometry or construction. Such variations in the present invention are to be construed and understood to be within the scope thereof.
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WE CLAIM:
1. A choke control device for a vehicle with a handlebar as steering means, comprising a push pull type mechanism, having a handle which moves along an axis wherein the axis of the push pull handle is transverse to the axis of the vehicle.
2. A choke control device as claimed in Claim 1 wherein the choke control device is mounted in the handlebar.
3. A choke control device according to Claim 2, wherein the handlebar includes a pair of laterally spaced hand grip attached to the handlebar on either side, said handlebar having a passage for communication with the plunger valve of the carburetor, said device comprising a control rod and a control knob for operating the control rod, wherein the said knob is co-axial to and perpendicularly external to the handlebar, and wherein the choke rod is arranged and oriented substantially within the tubular portion formed within the handlebar.
4. A choke control device as claimed in Claim 2, where the said device comprises a tubular portion adapted to be rigidly mounted within one end of the handlebar, a choke rod supported within the tubular portion for linear bidirectional movement along the axis which axis is transverse to the axis of the vehicle and a choke knob arranged at the end surface of the handlebar for manual operation of the choke rod;
5. A choke control device as claimed in Claim 3 where the choke rod is supported within the tubular portion for linear bidirectional movement along the longitudinal axis of the handlebar;
6. A choke control device as claimed in any of the Claims 3, 4 or 5, where the said device comprising of the control rod arranged inside the handlebar at the grip end and the control knob operating the control rod is arranged at distal end
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along the longitudinal axis of the handlebar, said control knob characterized in that it is accessible by the riders hand while seated and the said control knob further characterized in that it is visible when spaced away from the handlebar end.
7. A choke control device as claimed in any of the Claims 3 to 6, where the said device is mounted on a grip comprising of a housing adapted to be mounted within the handlebar, a bush extending to form a tubular hollow portion within the housing, a movable choke rod supported within the said hollow portion, an inner cable actuated by the movable choke rod, said choke rod actuated by a choke knob, and said valve plunger of the carburetor actuated by the inner cable and said control rod biased for preventing outward movement beyond prescribed length, the said device characterized in the knob co-axial fitted on the distal end surface of the handlebar.
8. A choke control device as claimed in any of the claims 2 to 7, where the said device is arranged on and inside portion of the handlebar said device comprising of:-
a. a choke knob arranged on a distal tip end surface of the handlebar
wherein the movement of the choke knob towards and away from the
handlebar surface end actuates correspondingly the movement of a
choke rod;
b. a movable choke rod operable by the choke knob, said rod arranged
within the distal end of the handlebar, which rod in turn actuates the
plunger valve of the carburetor through a set of cables;
9. A choke control device as claimed in Claim 8, where the said device is arranged on throttle grip;
10. A choke control device as claimed in Claim 8, where the said device arranged on hand shift grip;
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11. A handlebar comprising a choke control device as claimed in any of the Claims l to 10, the said handlebar including a pair of laterally spaced grip attached to the handlebar on either side, said handlebar having a passage for communication with the plunger valve of the carburetor, said device comprising of
a. an open end cylindrical hollow tube within the handlebar defining a
housing;
b. a bush adapted to be received at the distal end of the handlebar with
central axial aperture having an axially extending cylindrical hollow
tubular portion supported within the handlebar thereby defining a
cavity open into the handlebar;
c. a serrated choke rod movably supported within the hollow tubular
portion for relative bidirectional movement along the central axis and
movable by a manual force;
d. a choke knob adapted at the outer end of the said choke rod and
extending outwardly of the handlebar for moving the choke rod;
e. a retaining cap lock at the distal end of the housing adapted for mating
with the serrations on the choke rod, supported within the houses by a
holding means, said holding means comprising a ball and spring
mechanism at the distal end of the housing, said spring exerting
pressure on the ball so as to permit predetermined movement of the
choke rod between the cold start position spaced away from the
handlebar and a running position against the handlebar;
f. an inner cable coupled to the control rod at one end and coupled to the
plunger valve of the carburetor at the other end;
g. a ring for coupling the inner end of the choke rod within the housing to
one end of the inner cable, such that the movement of the choke rod is
transmitted to the inner cable, movement further transmitted to the
plunger valve of the carburetor;
12. The handlebar as claimed in Claim 11 where the choke control device is arranged at the throttle grip;
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13- The handlebar as claimed in Claim 11 where the choke control device is arranged at the hand shift grip;
14. A choke control device as claimed in claims 1 to 13, wherein the said choke rod having at least one flat surface, said flat surface having serrations substantially along its operative length;
15. A choke control device, as claimed in claims 1 to 14, said device comprising of a control rod having its outer end slightly extending outwardly of the handlebar wherein the control rod is adapted at its tip to form the control knob disposed outside of the handlebar.
16. A choke control device, as claimed in claim 1 to 15, said device comprising of a control rod having its outer end slightly extending outwardly of the handlebar wherein the control rod is adapted at its tip to form the control knob disposed outside of the handlebar.
17. A choke control device mounted in the handlebar, as claimed in claim 3 to 16, wherein the colour of the control knob is different from the colour of the handle grip.

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CHOKE CONTROL DEVICE FOR VEHICLES USING HANDLE BAR AS STEERING
CONTROL
ABSTRACT:
According to the present invention a choke control device for a vehicle with a handle bar as steering control, comprising a push pull type mechanism, having a handle which moves along an axis wherein the axis of the push pull handle is transverse to the axis of the vehicle and the invention is to provide a visual indication on the position of the choke control device and it is convenient to operator.