Technical Field
[0001] The present invention generally relates to a carburettor for a
two wheeled vehicle, and particularly relates to an. aeration tubing arrangement structure in said carburettor. Background
[0002] Typically, an intake system comprising a carburettor and an
air cleaner is arranged below a rear portion of a fuel tank of the
motorcycle. In scooter type motorcycles, the intake system is arranged
below a storage chamber and the tubings emerging from the carburettor
are routed along members of body frame of the motorcycle. For example
in a known art, an aeration tubing of the carburettor is routed along side
tubes of the body frame of the scooter type motorcycle. A.clamp mounted
on the side tubes is used to hold the aeration tubing, so that an aeration
hole of the aeration tubing remains open to the atmosphere.
[0003] The aeration tubing of the carburettor aids in maintaining
atmospheric pressure inside a fuel bowl of the carburettor. Further,.the aeration tubing also aids in carrying off fuel fumes and air bubbles formed in a discharge tube of the carburettor. Therefore, ventilation of the aeration tubing is essential to allow a continuous flow of fuel. However, since the aeration hole of the aeration tubing is open to the atmosphere, probability of blockage of the aeration tubing due to entry of dust and water is high, resulting in the motorcycle switching off. It is therefore desirable to ensure

s
that that the routing of the aeration tubing is such that there can be no
entry of dust or water.
[0004] Further, routing of the aeration tubing along the side tubes of
body frame as described in the above art is cumbersome causing difficulty
during assembly of the carburettor. Also, since a customer finds it
inconvenient to route the aeration tubing along the side tubes of the body
frame of the motorcycle, at most times during servicing of the carburettor,
the aeration tubing is allowed to dangle freely resulting in damage to the
aeration tubing.
[0005] Routing of the aeration tubing along the side tubes'of body
frame of the motorcycle also causes spillage of fuel from a fuel bowl of the
carburettor when the motorcycle tilts.
[0006] It is therefore desirable to address problems associated with
the above described design.
Summary of the Invention
[0007] The present invention has been made in view of the above
circumstances.
[0008] It is one object of the present invention to provide a
motorcycle including an aeration tubing arrangement structure for
receiving an aeration tubing of a carburettor.
[0009] It is another object of the present invention to provide an
aeration tubing arrangement structure, which enables to ensure that dust

entry and water entry into the aeration tubing of the carburettor is
prevented.
[0010] It is yet another object of the present invention to provide an
aeration tubing arrangement structure which eases and simplifies the
routing of the aeration tubing in the motorcycle.
[0011] It is still another object of the present invention to. provide an
aeration tubing arrangement structure which aids in preventing damage to
the aeration tubing of the carburettor.
[0012] It is still another object of the present invention to provide an
aeration tubing arrangement structure which aids in preventing fuel"
spillage from a fuel bowl of the carburettor when the motorcycle tilts.
[0013] It is one more object of the present invention to provide an
aeration tubing arrangement structure which aids in improving
performance of the carburettor of the motorcycle.
[0014] The above and other objects of the present invention are
achieved in accordance with the present invention by providing an
aeration tubing arrangement structure in a carburettor of the motorcycle.
The aeration tubing arrangement structure includes an extension member
disposed on the carburettor in a manner such that the extension member
extends at least partially away from the carburettor. Further, the extension
member has at least one orifice to- receive the aeration tubing of the
carburettor.

[0015] The aeration tubing arrangement structure in accordance
with the present invention ensures that the aeration tubing gets routed
besides the carburettor in a manner such at least a portion of the
carburettor covers an aeration hole of the aeration tubing at least partially.
Furthermore, routing of the aeration tubing involves mere insertion of the
aeration tubing in the at least one orifice of the extension member.
[0016] Thus, the aeration tubing arrangement structure in
accordance with the present invention involves a simplified and hassle
free routing of the aeration tubing. Moreover, since the aeration hole of the
aeration tubing is at least partially covered by at least a portion of the
carburettor, possibility of dust and water entry into the aeration tubing is
minimised. Thus, while the aeration hole remains open to the atmosphere,
dust and water entry through the hole is minimised, thereby enhancing
performance of the carburettor.
Brief Description of Accompanying Drawings
[0017] The above and other features, aspects, and advantages of
the subject matter will be better understood with regard to the following
description and accompanying drawings where:
[0018] FIG.1 illustrates a perspective view of a motorcycle in
accordance with an embodiment of the present invention.
[0019] FIG.2 illustrates a perspective view of a motorcycle body
frame assembly in accordance with an embodiment of the present
invention.

[0020] FIG.3 illustrates an enlarged view of air intake system of the
motorcycle in accordance with an embodiment of the present invention.
[0021] FIG.4 illustrates a carburettor depicting a first embodiment of
the aeration tubing arrangement structure in accordance with the present
invention.
[0022] FIG.5 illustrates a carburettor depicting a second
embodiment of the aeration tubing arrangement structure in accordance
with the present invention.
Detailed Description of the Preferred Embodiments
[0023] The present subject matter relates to a motorcycle including
an aeration tubing arrangement structure, which facilitates convenient
routing of an'aeration tubing of a carburettor said motorcycle.
[0024] . Exemplary embodiments detailing features of the aeration
tubing arrangement, in accordance with the present invention will be
described hereunder with reference to the accompanying drawings.
Various aspects of different embodiments of the present invention will
become discernible from the following description set out hereunder.
Rather, the following description provides a convenient illustration for
implementing exemplary embodiments of the invention. Further, it is to be
noted that terms "upper", "lower", "right", "left", "front", "rear", "forward",
"rearward", "downward", "upward", "top", "bottom" and like terms are used
herein based' on the illustrated state or in a standing state of said
motorcycle with a driver riding thereon unless otherwise specified.

Furthermore, a vehicle longitudinal axis refers to a front to rear axis relative to the motorcycle, while a vehicle lateral axis refers to a side to side, or left to right axis relative to the motorcycle. Also; it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. Further, it is to be noted that although the present invention has been exemplified for a scooter type motorcycle, the present invention is applicable for other two wheeled vehicles having an internal combustion engine and a throttle body.
[0025] Firstly a description is made of an entire schematic structure
of a motorcycle 10. FIG.1 is a perspective view of the motorcycle 10.
[0026] The motorcycle 10 includes a body frame assembly 11
(shown in FIG.2), for example an underbone body frame assembly, made
of steel or aluminium alloy and covered by various covers.
[0027] A front cover 1 is provided to cover a forward facing side of
the body frame assembly 11. A leg shield (not shown) is disposed behind the front cover 1 to protect a rider's legs. Left and right side covers 2 are disposed to cover left and right side sections of a rear portion of the body frame assembly 11.
[0028] A front portion of the body frame assembly 11 includes a
front fork 8 supported to a lower portion of a steering shaft connected to a head pipe 5. A front wheel 9 is journaled at a lower end of the front fork 8.

A front fender 12 is arranged above the front fork 8 to cover an upper" portion of the front wheel 9.
[0029] A seat-3 is disposed above the left and right side covers 2. A
fuel tank (not shown) is arranged under the seat 3.
[0030] A toggle link (not shown) is supported swingably on a lower
side of the left and right side covers 2. An engine 20 (shown in. FIG.2) is swingably supported on the toggle link (not shown) on a lower side of the left and right side covers 2, and is arranged downwardly and in front of the fuel tank. The engine 20 is powered by an air fuel mixture sent in by a carburettor" 25 (shown in FIG.2) to a combustion chamber of the engine 20.
[0031] Further, combustion gases generated by the engine 20 is let
out as exhaust from a muffler 27 extending along a right hand side of the motorcycle 10.
[0032] A rear wheel 30 driven by the engine 20 is supported at a
rear portion of the engine 20.
[0033] Furthermore, according to an embodiment of the invention,
the body frame assembly 11 of the motorcycle 10, as illustrated in FIG.2,
includes a head pipe 5, a down tube 6 extending rearwardly and
. downwardly from the head pipe 5, and left and right side tubes 7 extending
. rearwardly and inclinedlyupwards from the down tube 6.

[0034] As may be seen in the FIG. 2, the engine 20 is supported at
a lower portion, between the left and right side tubes 7 and is disposed between the front wheel 9 and the rear wheel 30.
[0035] The engine 20 includes a cylinder head 21 and a crankcase
(not shown). Particularly, the engine 20 includes a crankshaft for rotation inside the crankcase, and a piston connected to the crankshaft through a connecting rod. Further; in the cylinder head 21 an intake valve (not shown) and an exhaust valve formed on a face of the cylinder head 21, are provided.
[0036] The cylinder head 21 further includes a "camshaft for rotation
in the cylinder head 21, a cam provided on the camshaft, a rocker shaft,
and, a rocker arm coaxially supported for rocking motion on the rocker
shaft and rocked by the cam. The intake valve is directly driven by the
cam, and the exhaust valve isdriven by the rocker arm. In other words,
the engine 20 is a single overhead cam (SOHC) engine.
[0037] Further, as illustrated in FIG.2 and FIG.3, a carburettor 25 is
connected to'an intake port in the cylinder head 21 through an intake pipe (not shown). The carburettor 25 is connected to an air cleaner 27 through a connecting pipe 27a, wherein the air cleaner 27 lies in an upstream end of the carburettor 25. Thus, in accordance with an embodiment of the invention, intake pipe, the carburettor 25, the connecting pipe 27a, and the air cleaner 27 constitute the intake system of the motorcycle 10.

[0038] Clean air is supplied by the air cleaner 27 to the carburettor
25 as intake air. The air cleaner 27 includes an air cleaner box and an air cleaner element accommodated in the air cleaner box for filtering atmospheric air entering said air cleaner box.
[0039] Furthermore, the carburettor 25 is connected to the fuel tank
through a fuel inlet hose (not shown). The carburettor 25 atomizes a
predetermined amount of fuel supplied from the fuel tank, and supplies the
atomized fuel to the intake port in the cylinder head 21 together with the
intake air from the air cleaner 27, through an outlet hose.
[0040] In accordance with an embodiment of the present invention,
as illustrated in FIG.4, the carburettor 25 comprises a fuel bowl 25a that receives fuel from the fuel tank. Excess fuel collected in the fuel bowl 25a is drained out though a drain hose (not shown) extending from a base of the fuel bowl 25a. Further, a throttle valve 25b is disposed in an upper, portion of the carburettor 25, which is connected to an accelerator of the motorcycle 10. The throttle valve 25b comprises a piston, movement of which restricts airflow to the engine 20 either completely or partially, thereby controlling the amount of air-fuel mixture delivered to the intake port of the engine 20. When the throttle valve 25b is completely closed or nearly closed, a manifold vacuum created in the throttle valve 25b is sufficient to pull a small amount of fuel and air through small aeration holes located therein. When the throttle valve 25b is progressively.

opened, more and more air is allowed to flow through the connecting pipe 27a and into the engine 20.
[0041] Working of the motorcycle during cold start conditions is
facilitated with the help of an auto choke 26, disposed besides the throttle
valve 25b in an upper portion of the carburettor 25. Further, efficient
working of the carburettor 25 is ensured by maintaining atmospheric
pressure inside the fuel bowl 25a. The same is achieved by means of an
aeration tubing 25c extending from the carburettor 25 that opens to the
atmosphere. In other words, the aeration tubing 25c has one of its end
open, so as to allow entry of air through said end. Since the aeration
tubing 25c opens to the atmosphere, and since the probability of dust
entry and water entry into an aeration hole 25co is high, the present
disclosure provides a means to address the same.
[0042] In accordance with an embodiment of the. invention as
illustrated in FIG.4, an aeration tubing arrangement structure 25s is provided in the carburettor 25 which not only aids in routing of said aeration tubing 25c, but also aids in preventing dust and water entry into the aeration hole 25co of said aeration tubing 25c. The aeration tubing arrangement structure 25s is disposed on a' first surface 25f of the carburettor 25 and includes an extension member 25sa in a manner such that the extension member 25sa extends at least partially away from said first surface. The first surface 25f can be any surface of the carburettor with sufficient space, on which the extension member 25sa can be

disposed. Preferably, an upper surface may be chosen as the first surface 25f to dispose said extension member 25sa. Further, the extension member 25sa includes at least one orifice 25sb to receive the aeration tubing 25c. The extension member 25sa as per the present embodiment may be made of plastic, metal or an alloy.
[0043] In a first embodiment of the present invention, as illustrated
in FIG.4, the aeration tubing arrangement structure 25s including the extension member 25sa is fastened by means of a fastener 29 to an auto choke base member 26a formed on the carburettor 25, on which the auto choke 26 is mounted. Thus, in a first embodiment the aeration tubing arrangement structure 25s is disposed in a space between the throttle valve 25b and the auto choke 26.
[0044] In a second embodiment of the present invention, as
illustrated in FIG.5, the aeration tubing arrangement structure 25s including the extension member 25sa is formed integrally along with the base member 26a formed on the carburettor 25.
[0045] Thus, the construction of the aeration tubing arrangement
structure 25s is such that the aeration tubing 25c has to be merely inserted into the at least one orifice 25sb. Moreover, provision of the . aeration tubing arrangement structure 25s ensures that the aeration tubing 25c gets routed besides the first surface 25f of the carburettor 25, close to a body of the carburettor 25, thereby eliminating the need for a lengthy aeration tubing 25c. For example, as may be seen in FIG.4 and FIG.5, the

aeration tubing 25c gets routed around an upper portion of the carburettor 25, besides the throttle valve 25b and the auto choke 26 and is held intact in an overhead and inverted position around the upper portion of the carburettor 25. Overhead routing of the aeration tubing 25c ensures that there is no fuel spillage when the motorcycle gets tilted and the fuel is sent back to the fuel bowl 25a.
[0046] Additionally, the construction and arrangement of the
aeration tubing arrangement structure 25s ensures that the aeration hole
25co of the aeration tubing 25c faces a second surface 25g of the
carburettor 25, so that the second surface 25g, for example constituted by
an upper surface portion of the fuel bowl 25a, covers the aeration hole
25co of the aeration tubing 25c. Thereby, the second surface 25g of the
carburettor 25 acts as a barrier and prevents dust and water from entering
the aeration tubing 25c. However, to ensure that the aeration hole 25co of
the aeration tubing 25c is not completely covered by the second surface
25g, a cut of 40-45° is given at one end of the aeration tubing 25c. Even if
in another embodiment where the extension member 25sa is disposed on
any other surface of the carburettor 25, it is provided in a manner such
that, it is always ensured that the aeration tubing hole 25co is not
completely covered by any other part of the carburettor 25.
[0047] The present disclosure of the aeration tubing arrangement
structure 25s may not be restricted only to a carburettor and may be

provided in a throttle body used in a motorcycle operated by an electronic fuel injection engine.
[0048] While the present invention has been shown and described -
with reference to the foregoing preferred embodiments, it will be apparent
to those skilled in the art that changes in form, connection, and detail may
be made therein without departing from the spirit and scope of the
invention as defined in the appended claims.

1/We Claim:
1. An aeration tubing arrangement structure (25s) for a motorcycle (10), wherein said aeration tubing arrangement structure (25s) comprising an extension member (25sa) is disposed on a first surface (25f) of a carburettor (25), and wherein the extension member (25sa) adapted to receive an aeration tubing (25c) of the carburettor (25), extends at least partially away from the first surface (25f) of the carburettor (25) in a manner such that the aeration tubing (25c) gets arranged substantially besides said first surface (25f), and an aeration hole (25co) of said aeration tubing " (25c) faces a second surface (25g) of the carburettor (25) so as to be partially covered by said second surface (25g).
2. The aeration tubing arrangement structure (25s) as claimed in claim 1, wherein the aeration tubing (25c) at its one end includes a cut made at an angle 40-45° to form the aeration tubing hole (25co).
3. The aeration tubing arrangement structure (25s) as claimed in claim 1, wherein the aeration tubing (25c) is arranged besides a throttle valve (25b) of said carburettor (25) by means of said extension member (25sa).
4. The aeration tubing arrangement structure (25s) as claimed in
claim 1, wherein the extension member (25sa) includes at least an
orifice (25sb) to receive said aeration tubing (25c).

5. The aeration tubing arrangement structure (25s) as claimed in claim 1, wherein the first surface (25f) includes an auto choke base member (26a) on which an auto choke (26) is mounted.
6. The aeration tubing arrangement structure (25s) as claimed in claim 1, wherein the second surface (25g) includes an upper surface portion'of a fuel bowl (25a) of said carburettor (25).