FORM 2


THE PATENTS ACT, 1970 (39 of 1970)
As amended by the Patents (Amendment) Act, 2005
&
THE PATENTS RULES, 2003
As amended by the Patents (Amendment) Rules, 2005
COMPLETE SPECIFICATION (See section 10 and rule 13)

TITLE OF THE INVENTION
Fuel Supply Systems for Gas Powered Vehicles

INVENTOR

Name : Mohanavelu Parthiban
Nationality : Indian National
Address : Bajaj Auto Limited, Akurdi, Pune 411035
Maharashtra, India

APPLICANTS

Name : Bajaj Auto Limited
Nationality : Indian Company
Address : Akurdi, Pune 411035, Maharashtra, India

PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of this invention and the manner in which it is to be performed:


This invention relates to fuel supply systems for gas powered vehicles and, in particular, two wheel vehicles such as motorcycles and motor scooters.
Two wheel vehicles - such as motorcycles and motor scooters - are an important mode of personal transport, for example being used for commuting in and around cities. Such vehicles have engines operating on the two or four stroke cycle, employing petrol as a fuel. As environmental laws become more stringent, emissions from such vehicles are required to reduce. In addition, petrol costs may form a significant part of the vehicle operator's budget so a rising price of petrol consequently hinders the convenience of owning such a vehicle. One way of achieving environmental benefits in terms of better fuel combustion and lesser emissions while reducing fuel costs is to operate the vehicle through gas power. Gaseous fuels such as liquefied petroleum gas (LPG) and compressed natural gas (CNG) may be used with environmental and economic benefits.
Gas powered vehicles operating on the two stroke cycle, unlike petrol fuelled vehicles operating on the two stroke cycle, do not allow for premixing of lubricant with fuel to enable the lubrication of engine components such as pistons and cylinders. Instead, the vehicle is provided with a distinct lubricant supply circuit including an oil tank and an oil pump for feeding the lubricant.
There are, as yet, relatively few LPG refueling stations in India. Thus, it is currently desirable to have a "back up" fuel supply system in the event that a vehicle operator is caught in a situation where the gaseous fuel exhausts in a location where there is no refueling station, yet there may be relatively ready availability of liquid fuels, especially petroleum fuels. Such petroleum fuels are therefore convenient for the back-up fuel supply. In that case, the vehicle could include the gaseous fuel supply, optionally the petrol fuel supply, and the lubricant supply circuit (in case of vehicles operating on two stroke cycle). Such a concept, however, suggests a bulky vehicle construction which may be inconvenient to the vehicle operator.
It is therefore an object of the invention to provide a fuel supply system for a two wheel vehicle that is convenient to use and service, thereby achieving the benefits of
2

gaseous fuel operation advantageously with liquid fuel or petrol back-up, in a manner appealing to the vehicle owner and maintenance service provider.
With this object in view, the present invention provides a fuel supply system for a two wheel vehicle comprising a gaseous fuel supply having a gaseous fuel tank; a liquid fuel supply having a liquid fuel tank; and the vehicle having a body including a seat for the vehicle operator wherein the gaseous fuel tank and liquid fuel tank are accommodated proximate one another within the body and under the seat for the vehicle operator.
Conveniently, the two wheel vehicle is a motor scooter, as conventionally understood, or certain types of motorcycle. The vehicle may operate on two or four stroke cycle. The preferred gaseous fuel is liquefied petroleum gas (LPG) and the preferred liquid fuel is petrol. In such case, the LPG and petrol tanks may be co-located within a cavity formed within the body of the vehicle. Filling points allowing the re-filling of LPG and petrol tanks may likewise be co-located within the body or cavity. The cavity may be provided with a lid, openable to allow ready access to the filling points, desirably in a single operation. The seat of the vehicle may be used as the lid, being -for example - hingeably connected to the body allowing it to be tilted and opened to allow access to the filling points. The lid may be lockable and locking means, such as a key lock, may be provided to allow locking of the seat or lid into position.
Petrol fuelled two stroke motor scooters may be lubricated either through a pre-mix system or through a separate lubricant supply system, as must be provided for a gas powered motor scooter in any event. Pre-mix would not normally be used where a separate lubricant supply system is provided. However, in accordance with the invention, additional safety may be achieved by encouraging the operator of the two stroke motor scooter - through written instruction or other indicia - to also premix lubricant with petrol fuel so that lubrication may be sustained even on failure of the LPG lubricant system and/or exhaustion of LPG fuel each condition being notified to the operator of the vehicle by suitable alarm system, for example provided on the dashboard of the motor scooter. The filling point for the lubricant supply system may also be co-located within the body or cavity of the vehicle under the operator seat, allowing all three filling points (LPG, petrol and lubricant) to be readily accessed by
3

the vehicle operator. However, the lubricant filling point could be provided at a separate location.
The gaseous fuel tank is a pressure vessel which may be formed as a spherical, ellipsoid, or ovoid volume as suitable for pressure vessels. The gaseous fuel tank is preferably ovoid, advantageously being disposed with a wide axis disposed in substantially horizontal relation to the cavity. Further, the liquid fuel or petrol tank may be shaped to fit a shape and volume of the cavity of the body of the vehicle after selection of the volume and shape of the gaseous fuel tank. In this way, use of space and height within the body may be economized with packaging benefits for a motor scooter or other two wheel vehicle incorporating the fuel supply system of the invention. Such a two wheel vehicle forms another aspect of the present invention.
The LPG combustion system includes a regulator for regulating the LPG delivery to the engine, for example by an intake manifold of the engine through suitable conduit(s) passing through the body of the vehicle. The vehicle may incorporate a swing arm suitable for supporting components such as the rear wheel and suspension components. It could also logically be used to support the regulator. Conveniently, however, the regulator is located - in accordance with a further aspect of the invention - on the side of the vehicle opposite to the swing arm. If the LPG combustion system is required to operate in a low temperature environment, a heated vaporizer may be required and, preferably, packaged in the same area as the regulator.
The vehicle operator may be informed of availability of gaseous fuel, and particularly a "low" or "exhausted" LPG condition, by a suitable indicator and may then switch between LPG and petrol supplies by actuating a switch which operates valve(s) enabling the alternative fuel to be supplied to the engine. This switching may be automatic. Similarly, if lubricant or oil level is "low", then - as a safety feature - the engine may be caused to be inoperative with LPG as the fuel by safety switch means.
In a further inventive aspect, predicated on the possibility that the number of LPG refueling stations may increase in the future alleviating the need for liquid fuel backup, the present invention provides a fuel supply system for a two wheel vehicle comprising a gaseous fuel supply having a gaseous fuel tank, a regulator for
4

regulating gaseous fuel delivery to the engine and the vehicle having a body including a seat for the vehicle operator wherein the gaseous fuel tank is accommodated within the body under the seat for the vehicle operator and wherein the regulator is located on an side of the vehicle opposite to a swing arm thereof. In such case, shape and disposition of the gaseous fuel tank is again conveniently selected, for example to be of ovoid shape, to achieve packaging benefits as described above.
The invention may be more fully understood from the following description of preferred but non-limiting embodiments thereof made with reference to the accompanying drawings in which:
Figure 1 is a partial side sectional view of a two wheel vehicle being a four stroke motor scooter and incorporating the fuel supply system of one embodiment of the present invention.
Figure 2 is a partial top sectional view of the motor scooter shown in Figure 1.
Figure 3a is a partial side sectional view of a two wheel vehicle being a two stroke motor scooter and incorporating the oil supply system of one embodiment of the present invention.
Figure 3b is a partial top sectional view of the motor scooter shown in Figure 3a.
Referring now to Figures 1 and 2, there is shown a motor scooter 10 having a spark ignited engine operating on the four stroke cycle and gas powered by liquefied petroleum gas (LPG) fuel. Motor scooter 10 comprises a body 1 made up of two body half-sections la and lb which are welded together to form a cavity lc to accommodate fuel supply components to be described later. Body 1 is fitted with a seat 2 for the vehicle operator, that is, the rider of the motor scooter 10. Cavity lc is located under seat 2. Seat 2 is connected by a hinge to the remainder of the body 1, allowing it to act as a lid openable to enable access to the cavity lc as shown in Figure 1. Opening is achieved by tilting the seat 2 towards the front of the motor scooter 10. When closed, by pushing down on the seat 2, the seat may be locked into position by a locking means such as a key lock.
5

Cavity lc accommodates an LPG tank 3, for storing LPG fuel, which is of ovoid or ellipsoid shape appropriate to a pressure vessel. LPG cylinder 3 is clamped to body 1 with a wider axis of the tank 3 disposed horizontally to reduce height of the fuel supply component package. LPG tank 3 has mounted on it, a multi-valve 4 which contains valves required for LPG operation including the valve for intake of gas from an LPG re-filling valve 5 also fixed to LPG tank 3 under the seat 2. Pipes connect the outlet of re-filling valve 5 to LPG cylinder 3.
LPG is the primary fuel of operation of the motor scooter 10, for reasons of economy and environmental acceptability, but, as a back-up, the motor scooter 10 also incorporates a petrol fuel supply system to be used, for example, if the LPG supply fails for any reason. The petrol fuel supply system includes a petrol tank 7, a petrol tank cap 8 and a petrol outlet pipe 9. Petrol tank 7 is provided in cavity lc proximate the re-filling valve 5 and is again clamped to the body 1. The petrol tank inlet or filling point is illustrated by petrol tank cap 8. Petrol tank 7 delivers fuel to the engine of motor scooter 10 via petrol outlet pipe 9. Petrol tank 7 is provided to store petrol as a back-up fuel in the event that LPG supply exhausts. However, the operator of motor scooter 10 might choose to run petrol under other conditions as well. The capacity of petrol tank 7 enables lesser range than achievable through use of LPG fuel. As shown, the petrol tank 7 is selected to be of smaller volume than LPG cylinder 3 and may be shaped to conveniently fit within cavity lc after selection of the LPG cylinder 3 volume. This allows use of space to be minimised and has significant advantages in reducing the bulk of motor scooter 10 as the relative volumes of petrol tank 7 and LPG cylinder 3 may be selected such that they, and their filling points, may be co-located within cavity lc and under the seat 2 of motor scooter 10. The operator of the motor scooter is thus able to fill the motor scooter 10 with LPG and petrol fuel in a convenient manner, gaining access to both petrol and LPG filling points simultaneously simply by opening seat 2, by unlocking it and tilting it toward the front of the scooter 10, and connecting LPG and petrol supplies to re-filling valve 5 and petrol filling point 8 as required.
The operator of motor scooter 10 may be informed when re-filling of LPG or petrol is required by a suitable indicator provided, for example, on the dashboard. When a
6

"low" LPG condition is indicated, the vehicle operator may actuate a switch to operate a valve to change the fuel supply to the engine from LPG to petrol. An indicator may also be used to indicate a "low" oil condition. In such case, the engine could be rendered inoperative as an additional safety feature.
Modifications and variations to the fuel supply system of the present invention may be apparent to the skilled reader of this disclosure. Such modifications and variations are considered to be within the scope of the present invention. For example, in the case of a motor scooter 10 having an engine operating on the two stroke cycle, a filling point for the oil supply may be co-located with the LPG and petrol filling points 5 and 8 under the seat 2 of body 1. Alternatively, an oil tank 22 with filling connection may be fixed to one side of the body 1 of the motor scooter 10. In such case, as illustrated in Figures 3a and 3b, LPG and petrol filling points are co-located under the seat 2 of body 1 of the motor scooter 10 as above described. However, the filling point of the oil tank 22 is accessible after removing the bonnet 23. Further, the shape and capacity of the gas and liquid fuel tanks may vary as desired for a particular model of motor scooter.
7

We claim :
1. A fuel supply system for a two wheel vehicle comprising a gaseous fuel supply having a gaseous fuel tank; a liquid fuel supply having a liquid fuel tank; and the vehicle having a body including a seat for the vehicle operator wherein the gaseous fuel tank and liquid fuel tank are accommodated proximate one another within the body and under the seat for the vehicle operator.
2. The fuel supply system of claim 1 wherein the gaseous fuel tank and liquid fuel tank are co-located within a cavity within said body of the vehicle.
3. The fuel supply system of claim 2 wherein filling points of the gaseous fuel tank and liquid fuel tank are co-located within said body or cavity of the vehicle.
4. The fuel supply system of claim 3 wherein the cavity is provided with a lid openable to allow access to the filling points.
5. The fuel supply system of claim 4 wherein said lid is lockable.
6. The fuel supply system of claim 4 wherein the lid is a seat of said vehicle.
7. The fuel supply system of any one of claims 2 to 6 wherein a filling point for a lubrication system of said vehicle is provided in said body or cavity of the vehicle.
8. The fuel supply system of claim 1 including an indicator for indicating available level of gaseous fuel.
9. The fuel supply system of claim 8 including a switch actuable to enable liquid fuel to be supplied to an engine of the vehicle as an alternative fuel when available level of gaseous fuel is low or exhausted.
10. The fuel supply system of any one of claims 2 to 9 wherein the gaseous fuel tank is a pressure vessel of spherical, ellipsoid or ovoid volume.
8

11. The fuel supply system of claim 10 wherein the pressure vessel is of ovoid volume and disposed with a wide axis disposed in substantially horizontal relation to said cavity.
12. The fuel supply system of any one of the preceding claims wherein the liquid fuel tank is shaped to fit a shape and volume of the cavity of the vehicle body after selection of the shape and volume of the gaseous fuel tank.
13. The fuel supply system of any one of the preceding claims wherein the gaseous fuel supply includes a regulator and wherein said regulator is located on a side of the vehicle opposite to a swing arm thereof.
14. The fuel supply system of any one of the preceding claims wherein, when lubricant level is low, safety switch means cause an engine of the vehicle to be inoperative.
15. A fuel supply system for a two wheel vehicle comprising a gaseous fuel supply having a gaseous fuel tank, a regulator for regulating gaseous fuel delivery to an engine of the vehicle and the vehicle having a body including a seat for the vehicle operator wherein the gaseous fuel tank is accommodated within said body of the vehicle under the seat for the operator and wherein said regulator is located on a side of the vehicle to opposite to a swing arm thereof.
16. A motor vehicle including the fuel supply system of any one of the preceding claims.
17. The motor vehicle of claim 16 being a motor scooter.
18. A fuel supply system substantially as hereinbefore described with reference to the drawings.
9

19. A motor vehicle substantially as hereinbefore described with reference to the drawings.
Dated this 15th day of December 2006
10

Abstract
Disclosed is a fuel supply system for a two wheel vehicle (10) comprising a gaseous fuel supply having a gaseous fuel tank (3); a liquid fuel supply having a liquid fuel tank (7); and the vehicle (10) having a body (1) including a seat (2) for the vehicle operator wherein the gaseous fuel tank (3) and liquid fuel tank (7) are accommodated proximate one another within the body (1) and under the seat (2) for the vehicle operator.
15 DEC 2006