IMPROVED PRESSURE PAD MECHANISM FOR
CHOKE ASSEMBLY
FILED OF INVENTION
The present invention relates to a pressure pad mechanism, particularly, the present invention relates to a pressure pad mechanism for choke assembly.
BACKGROUND OF THE INVENTION
The choke assembly is used for internal combustion engines used in motor cycles. The choke assembly in motorcycles is integrated with the handlebar switch. The internal combustion (1C) engine has a spark plug for igniting the air-fuel mixture. The engine gives trouble in starting during winters because of low temperature ambient conditions. When the engine is cold and the rider tries to start it, the engine is runs at an extremely low RPM. Due to the cold conditions the engine needs a very rich mixture to start. In the cold starting conditions the choke mechanism plays a vital role in providing a rich mixture to the engine. A movable choke plate is placed in open condition at the air inlet face of the carburetor. The choke plate is actuated by a choke knob. Figure 1 shows a switch (1) mounted with a choke knob (2) provided on the handle bar of the motor cycle. The choke plate is connected to the choke knob (2) through a choke wire (3). When the choke knob (2) is pulled the choke plate covers the air inlet completely and hence the entire engine vacuum goes into pulling fuel through jets. Thus more fuel is injected into the engine which makes the air-fuel mixture fuel rich .Usually this very rich mixture allows the engine to fire once or twice if you then push the choke lever to the initial position i.e. moving the choke plate so as to open the air inlet, the engine will start running normally.
The actuating mechanism of the choke control system for a motorcycle is described here. The choke actuating knob or lever (2) can be situated in the proximity of the carburetor, on bottom of left hand handle bar switch, or may be located at the left hand side of the left handlebar switch (1) as shown in figure l.The choke knob/lever (2) of the mechanism

is used to pull a wire (3) which closes the air inlet of the carburetor. The choke knob (2) has to remain in the actuated position until the engine has been started by means of self start or kick start. When the choke knob is in the pulled position carburetor air inlet is covered and hence the entire engine vacuum created goes into pulling the fuel from jets. More fuel pulled means a fuel rich mixture is going to the combustion chamber of the 1C engine.
Figure 2 illustrates the existing pressure pad mechanism used for keeping the choke knob/lever in pulled position. As shown in figure 2 a spring loaded pressure pad (10) is provided which applies pressure on to the choke lever (2) against the force exerted by the choke pull wire (3) and hold it in the pulled position. As shown in figure 2 the pressure pad mechanism includes a spring (20), a pressure pad (10), a retainer plate (30) and a screw (40) for securing the mechanism in the switch.
As shown in figure 3 the choke pull wire is secured in the choke lever /knob (2) and the pressure pad (10) is assembled from the outside of the switch (1) and is secured tightly on to the lower part of the switch with the support of retainer plate (30) and a screw (40). Figure 4 and Figure 5 shows the existing pressure pad (10) and switch (1) with a pocket (50) for accommodating the existing pressure pad (10) respectively.
In the existing pressure pad mechanism for keeping the choke knob (2) in pulled position the pressure pad (10) is assembled from the outside of the handlebar switch (1), hence, the mechanism can be tempered by any one which can lead to the failure of the functional requirement of the pressure pad mechanism.
The existing pressure mechanism, require two metal parts which have special requirement of plating to avoid the environmental corrosion of materials. Also, due to vibrations the mounting screw has a chance of occurrence of loosing out and falling in the field during vehicle movement thereby mechanism may fail to operate.

Therefore, there exists a need to develop a pressure pad mechanism for choke which overcomes the above mentioned drawbacks.
OBJECTS OF THE PRESENT INVENTION
The main object of the present invention is to provide a pressure pad mechanism for
choke assembly.
Another object of the present invention is to provide a choke assembly with an improved
pressure pad mechanism which overcomes at least one of the problems of the existing
mechanism.
SUMMARY OF THE INVENTION
The present invention provides a pressure pad mechanism for a choke assembly. Also the present invention provides a choke assembly with improved pressure pad mechanism. The choke assembly and pressure pad mechanism disclosed in the present invention is requires less number of components and tamper proof.
BRIEF DESCRIPTION OF FIGURES
Figure 1 illustrates the switch assembly showing the movement of the choke knob.
Figure 2 illustrates the sectional view of the existing pressure pad mechanism.
Figure 3 shows the exploded view of the existing pressure pad mechanism.
Figure 4 shows the pressure pad used for the existing pressure pad mechanism.
Figure 5 shows the switch with the pocket for pressure pad used for existing pressure pad
mechanism.
Figure 6 is an exemplary illustration of sectional view of the pressure pad mechanism
according to an embodiment of the present invention.
Figure 7 is an exemplary illustration of exploded view of the pressure pad mechanism of
the present invention.
Figure 8 (a) is an exemplary illustration of the choke lever.
Figure 8 (b) is an exemplary illustration of the pressure pad for the pressure pad
mechanism of the present invention.

"igure 9 is an exemplary illustration of the switch with pocket for pressure pad used for pressure pad mechanism of the present invention.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
Accordingly, the present invention provides a pressure pad mechanism for a choke
assembly having a knob being disposed in handlebar switch of a two wheeler, said
pressure pad mechanism comprising:
a pressure pad having a cylindrical hollow body closed at one end and open at other end;
said closed end has a wedge shaped outer face which engages with the knob; said open
end of the pressure pad is provided with an outwardly protruding portion;
a housing located at lower part of the handle bar switch and said housing comprises an
open top end and a closed bottom end;
a locking means provided in the housing for lockingly engage protruding portion of the
pressure pad inside the housing; and
said pressure pad is being movable from the location of the locking means to the closed
bottom end of the housing under a force of a spring being disposed between the pressure
pad and the bottom end of the housing;
In an embodiment of the present invention the housing is located inside the handle bar switch.
In another embodiment of the present invention the housing is integrally formed with the lower part of the handle bar switch.
In still another embodiment of the present invention the housing is provided with a projection for locating the spring inside the housing.
In yet another embodiment of the present invention the said protruding portions is in the form of a protruding rim or in the form of a "L" shaped projections.

In a further embodiment of the present invention the locking means is in the form of stops formed inside the housing arranged to cooperate with the protruding portion.
In a further more embodiment of the present invention the locking means is in the form of slots formed in the housing arranged to cooperate with the protruding portion.
In another embodiment of the present invention the pressure pad is made up of a material selected from the group comprising plastic, nylon plain, nylon glass filled, Poly Propylene talc filled, Poly acetyl.
The present invention also provides a choke assembly being disposed in handlebar switch
of two wheeler, said choke assembly comprising:
a choke knob pivotable in a plane perpendicular to a longitudinal direction of a grip of the
handle of the two wheeler; said knob comprises a handle portion and curved bottom
portion;
a pressure pad having a cylindrical hollow body closed at one end and open at other end;
said closed end has a wedge shaped outer face which engages with the knob; said open
end of the pressure pad is provided with an outwardly protruding portion;
a housing located at lower part of the handle bar switch and said housing comprises an
open top end and a closed bottom end;
a locking means provided in the housing for lockingly engage protruding portion of the
pressure pad inside the housing; and
said pressure pad is being movable from the location of the locking means to the closed
bottom end of the housing under a force of a spring being disposed between the pressure
pad and the bottom end of the housing;
In an embodiment of the present invention the housing is integrally formed with the switch.
In another embodiment of the present invention the knob is pivotable in a plane perpendicular to a longitudinal direction of a grip of the handle bar of the two wheeler.

In still another embodiment of the present invention the knob comprises a handle portion and a curved bottom portion.
In yet another embodiment of the present invention the knob is connected with an end of the choke wire such that the movement of the knob actuates the choke.
In one more embodiment of the present invention the present invention provides an improved pressure pad mechanism for choke assembly which overcomes the drawbacks of the existing pressure pad mechanism.
Before describing in detail embodiments that are in accordance with the present invention, it should be observed that nothing contained in this section is intended to limit the scope of the invention. The scope of the invention is intended to be limited purely by the claims and its equivalence. The following detailed description of the embodiments is provided purely to enhance the understanding of the invention and to assist a person reading the document to work the invention. Accordingly, the elements (or in other words the components) of the device have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments 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 device that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such device. Also, it should be observed that an element proceeded by "comprises... a" does not, without more constraints, preclude the existence of additional identical elements in the device that comprises the element.
The present invention is described with reference to the figures and specific embodiments; this description is not meant to be construed in a limiting sense. Various alternate embodiments of the invention, will become apparent to persons skilled in the art

ipon reference to the description of the invention. It is therefore contemplated that such alternative embodiments form part of the present invention.
Accordingly, the present invention provides an improved pressure pad mechanism for a choke assembly. The choke assembly has a knob and usually it is disposed in the handle bar switch of a two wheeler. The pressure pad mechanism of the present invention preferably comprises a pressure pad which has a cylindrical hollow body which is closed at one end and open at the other end. The closed end of the pressure pad may be formed so as to have a wedge shaped outer surface. The knob of the choke assembly has a handle portion and curved bottom portion. The wedge shaped outer surface engages or arranged to be in contact with the curved bottom portion of the knob. The open end of the pressure pad may be provided with an outwardly protruding portion.
The pressure pad can be placed in a housing inside the handle bar switch. The housing can be placed in lower part of the switch and the housing can be integrally formed with the lower part of the switch. The housing has a closed bottom end and an open top end for receiving the pressure pad. The housing is provided with locking means for lockingly engaging the protruding portion of the pressure pad. The locking means can be located at some intermediate location in the housing between the open top end and the closed bottom end. As it can be clearly understood the pressure pad is movable between the location of the locking means and the bottom end of the housing. A spring is disposed inside the housing, between the pressure pad and the bottom end of the housing. The open end of the pressure pad in configured to receive the spring. A projection can be provided at the bottom end of the housing for locating the spring inside the housing.
As it can be clearly understood from the above paragraph that the pressure pad is placed inside the housing under the force of the spring and locking means engages the protruding portion of the pressure pad inside the housing. This arrangement allows the movement of the pressure pad from the location of the locking means to the bottom end of the housing. However, the pressure pad is not allowed to move from the location of the locking means to the top end of the housing.

The protruding portions provided on the pressure pad can be made in the form of a protruding rim or alternatively, the protruding portions can be in the form of 'L' shaped projections. The locking means provided in the housing can be in the form of stops which co-operate with the protruding portion of the pressure pad and engage the pressure pad. Alternatively, the locking means is in the form of slot formed in the housing so that the slot receives the protruding portion of the pressure pad.
The pressured pad of the pressure pad mechanism of the present invention can be made up of material selected from the group comprising plastic, nylon plain, nylon glass filled, Poly Propylene talc filled, Poly acetyl.
The pressure pad mechanism of the present invention can be suitably used in the choke assembly. Accordingly, the present invention provides a choke assembly being disposed in the handle-bar switch of two wheeler. The handle bar switch generally has two parts i.e. upper part and the lower part. The choke assembly comprises a choke knob which has a handle portion and a curved bottom portion. The choke knob is generally disposed in the upper part of the handle bar switch. The choke knob is pivotable in a plane perpendicular to a longitudinal direction of a grip of the handle of the two wheeler. It can be clearly observed that, by this particular arrangement the actuation of handle portion of the choke knob actuates the curved bottom portion of the choke knob in arcuate direction.
The choke knob is connected with an end of a choke wire so that the actuation of the handle portion of the choke knob actuates the choke. The choke wire exerts a return force which tends to bring the choke knob in its original position. The choke knob is held in pulled position by the pressure pad mechanism disposed in lower part of the switch. According to an embodiment of the present invention the curved bottom portion of the choke knob is kept in contact with a spring loaded pressure pad. The pressure pad of the present invention has a cylindrical hollow body which is closed at one end and open at the other end. The closed end of the pressure pad may be formed so as to have a wedge shaped outer surface. The open end of the choke knob is provided with outwardly protruding portion. The pressure pad is placed inside a housing provided in the lower part

the switch. The housing can be affixed inside the housing or alternatively, the housing can be integrally formed with the lower part of the switch. The housing has an open top end and a closed bottom end. The pressure pad is placed inside the housing under a force of a spring disposed between the pressure pad and the bottom end of the housing. The protruding portion of the pressure pad is locked inside the housing with the help of locking means provided in the housing. A projection can be provided at the bottom end of the housing for locating the spring inside the housing. The protruding portion of the pressure pad can be in the form of protruding rim or alternatively, the protruding portion can be in the form of 'L' shaped projection.
The locking means provided in the housing can be in the form of stops or in the form of slots arranged to cooperate with the protruding portion for lockingly engaging the pressure pad inside the housing under a force of the spring.
The choke knob is placed in such a manner so that the wedge shaped outer surface of the spring loaded pressure pad always being in contact with the curved bottom portion of the choke knob. The pressure pad of the present invention holds the choke knob in pulled position.
The following description describes the present invention with reference to the figures, however, the following description should not be construed in a limiting sense.
Figures 6 and 7 illustrate the sectional and exploded view of the switch with choke assembly which incorporates the pressure pad mechanism according to an embodiment of the present invention. As can be noticed from figures 6 and 7 the pressure pad mechanism of the present invention comprises a housing (100) which houses a pressure pad (200) having two legs with snap fitting (300) and a spring (400). Figure 8(a) shows an enlarged view of the choke lever/ knob (500). The choke lever/knob (500) comprises a handle portion (600) and a curved bottom portion (700) connected to each other in such a way that by moving the choke knob (500) the curved bottom portion (700) performs a circular/ arcuate motion. The handle portion (600) is used to actuate the choke knob (500)

manual force and. The enlarged view of the pressure pad (200) for pressure pad P mechanism of the present invention is shown in figure 8 (b). Whereas figure 9 shows the
pocket for the pressure pad used in the pressure pad mechanism of the present invention.
As can be observed from figure 6 and 7, the housing (100) is provided in the lower part of the switch. Alternatively, the lower part of the switch can be formed in the form of the housing (100). In other words the housing (100) can be integrally formed with the switch. The internal wall of the housing (100) is designed in the form of stop (300') so as to lock the snap fitting provided on pressure pad (200). The top of the housing comprises an open top end (800) and a closed bottom end (900). The bottom end (900) of the housing (100) is provided with a projection (1000) for placing the spring (400).
In the pressure pad mechanism of the present invention the pressure pad is assembled from the inside rather than from outside of the lower part of the handlebar switch. For assembling the pressure pad mechanism of the present invention, the spring (400) is first placed on the projection (1000) inside the housing (100). After placing the spring (400) the pressure pad (200) is placed inside the housing (100) against the force of the spring (400). The pressure pad (200) is locked with the help of snap fit provided on the pressure pad (200) and stops provided on the internal wall of the housing (100).
After assembling the pressure pad mechanism as above, the choke knob is assembled in the switch. The pressure pad (200) is actuated by moving the choke knob (2) to 'ON' position. As can be observed from figure 8(a), when the choke knob is moved from 'OFF' position the curved bottom end of the choke knob moves which in turn actuates the pressure pad (200). As the choke knob moves from its original position (i.e. OFF position) the choke wire (3) applies return pressure/force to bring the choke knob (2) to its original position but due to the resisting force of the spring loaded pressure pad (200) the choke knob (2) does not return back to its original position. To move the choke knob (2) to its original position the manual pressure has to be applied on the choke knob (2). The manual pressure for moving the knob should be greater than the resisting force applied by the pressure pad (200). When the choke knob (500) is moved from its 'ON'

position to its original position (i.e. OFF position) the pressure pad (200) moves in upward direction due to the force of the spring (400). The pressure pad moves upward till the snap fit provided on the pressure pad meets the stops provided on the housing.
In the .present invention the pressure pad mechanism is assembled without using the screw and retainer plate. Because screw and the retainer plate have not been used, the present invention reduces the number of components of the choke assembly. The lower part of the switch has been modified to incorporate the pressure pad (200) from inside and the outer slot for assembly of the pressure pad mechanism has been covered by merging with the case lower switch.
The pressure pad has been changed to have two legs with snap fitting which helps the pad to remain locked with the lower part of the switch.
This arrangement enables the movement of the pressure pad to remain the same as it was earlier and the same specification spring ensure the same kind of force initiated on the choke lever.
In an embodiment of the present invention the pressure pad mechanism incorporates two slots at the lower face of the lower part of the switch or at the bottom end of the housing. This provides a scope for replacement of the pressure pad by using the two slots. When two pins of the suitable diameter are pushed inside the slots the pressure pad is forced to unlock by pushing the legs of the pressure pad inwards.
Hence without changing the resultant effect of the pressure pad mechanism the same specifications are achieved with improved reliability less number of parts and safe temper proof assembly of the mechanism inside the lower part of the handlebar switch.
The foregoing detailed description has described only a few of the many possible implementations of the present invention. Thus, the detailed description is given only by

way of illustration and nothing contained in this section should be construed to limit the ' scope of the invention.

We Claim:
1. A pressure pad mechanism for a choke assembly having a knob being disposed in
handlebar switch of a two wheeler, said pressure pad mechanism comprising:
a pressure pad (200) having a cylindrical hollow body closed at one end and open at other
end; said closed end has a wedge shaped outer face which engages with the knob; said
open end of the pressure pad (200) is provided with an outwardly protruding portion
(300);
a housing (100) located at lower part of the handle bar switch and said housing (100)
comprises an open top end (800) and a closed bottom end (900);
a locking means (300') provided in the housing for lockingly engage protruding portion
(300) of the pressure pad (200) inside the housing (100); and
said pressure pad (200) is being movable from the location of the locking means (300') to
the closed bottom end (900) of the housing (100) under a force of a spring (400) being
disposed between the pressure pad (200) and the bottom end (900) of the housing (100);
2. A pressure pad mechanism as claimed in claims 1, wherein the housing (100) is located
inside the handle bar switch.
3. A pressure pad mechanism as claimed in claims 1 and 2, wherein the housing (100) is
integrally formed with the lower part of the handle bar switch.
4. A pressure pad mechanism as claimed in claim any one of the preceding claims 1 to 3,
wherein the housing (100) is provided with a projection (1000) for locating the spring
(400) inside the housing (100).
5. A pressure pad mechanism as claimed in any one of the preceding claims 1 to 4, wherein
the said protruding portions (300) is in the form of a protruding rim or in the form of a
"L" shaped projections.

6. A pressure pad mechanism as claimed in any one of the preceding claims 1 to 5, wherein
the locking means (300') is in the form of stops formed inside the housing arranged to
cooperate with the protruding portion.
7. A pressure pad mechanism as claimed in any one of the preceding claims 1 to 5, wherein
the locking means (300') is in the form of slots formed in the housing arranged to
cooperate with the protruding portion.
8. A pressure pad mechanism as claimed in any one of the preceding claims 1 to 7, wherein
the pressure pad (200) is made up of a material selected from the group comprising
plastic, nylon plain ,nylon glass filled, Poly Propylene talc filled, Poly acetyl.
9. A choke assembly being disposed in handlebar switch of two wheeler comprising:
a choke knob (500) pivotable in a plane perpendicular to a longitudinal direction of a grip
of the handle of the two wheeler; said choke knob (500) comprises a handle portion (600)
and curved bottom portion (700);
a pressure pad (200) having a cylindrical hollow body closed at one end and open at other
end; said closed end has a wedge shaped outer face which engages with the choke knob
(500); said open end of the pressure pad is provided with an outwardly protruding portion
(300);
a housing (100) located at lower part of the handle bar switch and said housing comprises
an open top end (800) and a closed bottom end (900);
a locking means (300') provided in the housing (100) for lockingly engage protruding
portion (300) of the pressure pad (200) inside the housing (100); and
said pressure pad (200) is being movable from the location of the locking means (300') to
the closed bottom end (900) of the housing (100) under a force of a spring (400) being
disposed between the pressure pad (200) and the bottom end (900) of the housing (100).
10. A choke assembly as claimed in claim 9, wherein the housing (100) is integrally formed
with the switch.

11. 'A choke assembly as claimed in claims 9 to 10, wherein the choke knob (500) is
' pivotable in a plane perpendicular to a longitudinal direction of a grip of the handle bar of
the two wheeler.
12. A choke assembly as claimed in claims 9 to 11, wherein the choke knob (500) comprises
a handle portion (600) and a curved bottom portion (700).
13. A choke assembly as claimed in claims 9 to 12, wherein the choke knob (500) is
connected with an end of the choke wire such that the movement of the choke knob
actuates the choke.
14. A pressure pad mechanism and a choke assembly substantially as herein described with
reference to the accompanying drawings.