Title of Invention	LPG KIT WITH LIQUID LPG WITHDRAWAL SYSTEM FOR USE IN 2-STROKE MARINE ENGINES
Abstract	The invention is in regard to a LPG kit fitted with a liquid withdrawal system for use in marine engines comprising a replaceable LPG cylinder, a liquid withdrawal cylinder valve fitted at the neck of said LPG cylinder, a dip tube being fixed at the lower end of said liquid withdrawal cylinder valve which enters said LPG cylinder almost upto its bottom and remains dipped in liquid LPG; a valve adaptor being fitted on said cylinder valve provided with a knob to turn on or off the LPG supply to the system, a LPG regulator being connected to said LPG valve adaptor with a hose tube, a gas flow control valve being fitted to the outlet of said regulator , a gas- air mixer unit being fitted on the carburetor air intake side adjacent to the air box of an engine, said mixture unit and said gas flow control unit being connected by a LPG hose; said system includes an oil tank, a vacuum operated on / off valve and an oil flow control unit; said oil tank being connected to said vacuum operated valve by an oil hose, said vacuum operated valve being connected to said engine, said engine oil flow unit and said mixer unit by said oil hoses.

Title of Invention

LPG KIT WITH LIQUID LPG WITHDRAWAL SYSTEM FOR USE IN 2-STROKE MARINE ENGINES

Abstract

The invention is in regard to a LPG kit fitted with a liquid withdrawal system for use in marine engines comprising a replaceable LPG cylinder, a liquid withdrawal cylinder valve fitted at the neck of said LPG cylinder, a dip tube being fixed at the lower end of said liquid withdrawal cylinder valve which enters said LPG cylinder almost upto its bottom and remains dipped in liquid LPG; a valve adaptor being fitted on said cylinder valve provided with a knob to turn on or off the LPG supply to the system, a LPG regulator being connected to said LPG valve adaptor with a hose tube, a gas flow control valve being fitted to the outlet of said regulator , a gas- air mixer unit being fitted on the carburetor air intake side adjacent to the air box of an engine, said mixture unit and said gas flow control unit being connected by a LPG hose; said system includes an oil tank, a vacuum operated on / off valve and an oil flow control unit; said oil tank being connected to said vacuum operated valve by an oil hose, said vacuum operated valve being connected to said engine, said engine oil flow unit and said mixer unit by said oil hoses.

Full Text	FORM-2 THE PATENTS ACT, 1970 (39 OF 1970) AND THE PATENTS RULES, 2003 COMPLETE SPECIFICATION (See Section 10, Rule 13) TITLE LPG KIT WITH LIQUID LPG WITHDRAWAL SYSTEM FOR MARINE ENGINES APPLICANT Vanaz Engineers Ltd. of 85 /1 Paud Road, Pune - 411 029, Maharastra, India, an Indian Company Registered under the provisions of the Companies Act, 1956 The following specification particularly describes the invention and the manner in which it is to be performed TITLE LPG KIT WITH LIQUID LPG WITHDRAWAL SYSTEM FOR MARINE ENGINES Field of invention The present invention relates to a LPG kit for marine engines used in various watercrafts and marine vessels. This invention particularly relates to a LPG kit with liquid LPG withdrawal system to run gasoline marine engines on Liquefied Petroleum Gas (LPG). Such engines are ordinarily used in fishing boats and for other marine vessels for different applications. LPG kit of the present invention is suitable for 2/4 stroke single or multi cylinder outboard motors and other engines for marine applications. Prior Art At present the boats used in fishing along the Indian coastal areas / belt are mostly powered with 2 stroke single or multi cylinder or even 4 stroke single or multi cylinder outboard motors or engines of various makes ranging from 9.9 HP to 110 HP motors. Out of this range, more popularly used outboard motors are of capacities between 9.9 HP to 40 HP. Even in the above range, the majority of outboard motors are of capacity 9.9 HP to 25 HP engines. All these engines are basically Spark Ignition (SI) type engines which run on conventional fuels like petrol or kerosene or petrol start and kerosene run. Due to the extensive use of these conventional fueled engines, the pollution levels particularly along the coastal zones are regularly increasing to a level which is much higher than the expected level. Moreover, the numbers of such motors are rapidly increasing day by day, thus increasing the pollution to alarming high level causing serious threats and health hazards. This is a matter of great concern. Further, the cost of running these engines on conventional fuels is considerably high. As a result reductions of pollutant emission level and cost of fuel have become important issues and considered to be required immediate attention. 1 Invention To avoid the aforesaid drawbacks a great deal of research works have been done particularly in the automotive sector for utilizing alternative fuels like LPG and CNG for 2, 3 and 4 wheeler, commercial vehicles and heavy commercial vehicles which are powered by 2 stroke or 4 stroke single and / or multi cylinder engines. The use of LPG for outboard motors and other marine engines has not been successfully developed till date upto the expectation and / or desired requirement of the users. The known kits used for conversion of marine engines employing LPG vapour withdrawal system. In such system LPG is withdrawn from the cylinder in gaseous state, the vaporization takes place in the cylinder itself. As the LPG consumption increases due to the higher fuel demand from the Engine, the vaporization rate of liquid LPG inside the cylinder steadily increases, due to this the LPG cylinder temperature reduces to such an extent that it goes even below zero degree, resulting in to reduction in supply of gaseous LPG from the cylinder and further stopping of Engine itself. Such systems therefore either restrain the engine power capacity or necessitate the use of large capacity or multiple cylinder banks. Multiple cylinders occupy a major space in rather small fishing vessels and also add unnecessary weight to the boat. These ultimately result loss of speed, less storage space for the catch and requires more fuel to run the engine. Moreover, handling of large capacity or multiple LPG cylinders become inconvenient and difficult. Improper placement of large capacity cylinders sometimes lead to uneven distribution of load and often causing toppling of the vessels in the wavy sea. One of the objects of the present invention is to mitigate the disadvantages as experienced in the prior art and as described herein above in using the known marine engines particularly for the fishing vessels. In the present invention the liquid LPG is withdrawn from the cylinder and vaporized in the Regulator/Vaporizer with the help of Hot/Warm water circulated from Engine cooling jacket. As liquid is withdrawn from the cylinder, no major vapourization takes place in cylinder itself and thus totally avoids cooling/chilling of the cylinder. This enables to get uninterrupted supply of LPG from the cylinder as per the engine demand. 2 A further object of the present invention is to provide a LPG kit with liquid LPG withdrawal system having less weight thereby enhancing the speed of the fishing boat. A still further object of the present invention is to provide a LPG kit with liquid LPG withdrawal system having smaller dimension, thereby providing more storage space in the marine vessels namely fishing boats. Another object of the present invention is to provide a LPG kit with liquid LPG withdrawal system which consumes less fuel for the fishing boat. Yet another object of the present invention is to have a liquid LPG kit with liquid withdrawal LPG system for marine engines emitting less pollutant in the surrounding atmosphere, and thus reducing the health hazard. In one embodiment of the present invention, the LPG cylinder valve withdraws liquid LPG from the cylinder and supplies it to the kit vaporizer where liquid LPG is vaporized and the liquid LPG is supplied to the engine through the gas - air mixer. In another embodiment of the present invention, small replaceable cylinders of less weight and capacity are used for convenience since such would occupy less space and at the same time supply sufficient quantity of liquid LPG required for the optimum speed and load performance of the marine engines. In still another embodiment of the present invention such LPG cylinders are placed on the floor of the vessel. This lowers the load and balances the centre of gravity which gives more stability of the vessel and more storage space for the catch. In a further embodiment of the present invention, only required numbers of small LPG cylinders are used for reducing the weight of the marine vessel and such cylinders occupy less area or volume in the vessel. One more object of the present invention is to produce comparatively smaller, lighter and more economical marine vessel, particularly suitable as fishing boat. 3 According to this invention there is provided a LPG kit fitted with a liquid withdrawal system for use in marine engines comprising a replaceable LPG cylinder for holding liquid LPG, a liquid withdrawal cylinder valve fitted at the neck of said LPG cylinder, a dip tube being fixed at the lower end of said liquid withdrawal cylinder valve, the other end of said dip tube enters into extends almost upto the inner bottom surface of said cylinder and remains dipped in liquid LPG; a valve adaptor being fitted on said cylinder valve provided with a knob to turn on or off the LPG supply to the system, a LPG regulator being connected to said LPG valve adaptor with a hose tube, a gas flow control valve being fitted to the outlet of said regulator , a gas- air mixer unit being fitted on the carburetor air intake side adjacent to the air box of an engine, said mixture unit and said gas flow control unit being connected by a LPG hose ; said system includes an oil tank , a vacuum operated on / off valve and an oil flow control unit; said oil tank being connected to said vacuum operated valve by an oil hose said vacuum operated valve being connected to said engine, said engine oil flow unit and said mixer unit by said oil hoses. In the LPG kit of the present invention there is provided a LPG cylinder valve comprising a metal forged body which accommodates a valve assembly substantially similar to a said closing valve, said metal forged body is having a lower stub portion provided with taper threads suitable for making a leak proof joint with threads of the bungs of replaceable LPG cylinder, upper portion or collar of said valve is machined to hold LPG valve adaptor. The said collar is preferably provided with a seal and internal profile to make it leak proof tight joint with said adaptor. At the lower end of the valve body and Excess Flow Check Valve is provided which goes inside the LPG Cylinder. In the LPG kit fitted with the liquid withdrawal system of this invention is provided with a leak proof sealing arrangement with a groove on the collar of the valve in which a pawl or locking balls of the adaptor are used to mesh for retaining said adaptor rigidly on said valve. Quite often a metallic tube is fixed at the bottom of said valve body so that LPG vapour does not escape out of the tank and the length of the tube is maintained such that it remains just above the inner bottom surface of the LPG cylinder to facilitate maximum liquid withdrawal. 4 The LPG kit is preferably adapted for 2 -stroke but not particularly limited to 2 strokes marine engines running on bi-fuel where LPG cylinder contains liquid LPG maximum upto 80% of its volume. In one of the aspect the present invention, the LPG kit is fitted with liquid withdrawal system where the hot / warm water from Engine water jacket is connected to vaporizer through the hot water circulation hoses which is used to vapourise liquid LPG to Gaseous LPG. In another aspect of the present invention, the 2 stroke engine is provided with a lubrication system where the engine is run on LPG fuel and the oil is supplied to the engine through a vacuum operated on/off valve and flow control unit connected together by oil hose and one end of said vacuum operated valve being connected to the engine manifold for sensing vacuum. This invention will now be described in detail with reference to the accompanying drawings wherein - Fig.l illustrates a LPG kit with liquid withdrawal system for use in a marine engine; and Fig.2 illustrates the LPG cylinder used in the marine engine as shown in Fig.l. The accompanying drawings show a 2 stroke marine engine run on bi-fuel. The system comprises a replaceable LPG cylinder (10) containing liquid LPG maximum upto 80% of its volume. A liquid withdrawal cylinder valve (12) is fitted at the neck portion of said cylinder. A dip tube (15) is fixed at the lower end of the valve which enters the LPG cylinder and extends almost upto its inner bottom surface so as to be dipped in liquid LPG. An adaptor (23) is fitted on the cylinder valve which is provided with a knob to turn on and off the supply of LPG to the system. A LPG vaporizer (25) is connected to said LPG valve adaptor (23) by a hose tube (30). A gas flow control valve (36) is fitted to the outlet of the vaporizer / regulator (40). A gas- air mixer unit (43) is fitted on the carburetor air intake side 5 placed adjacent to the air box of the engine (45). The mixer unit and the said gas flow control unit are connected by a LPG hose (48). The engine jacket and the vaporizer are connected by a hot water circulation hoses. Further the vaporizer vacuum port and the engine manifold are connected by a vacuum hose. In case the system has to run on a two stoke engine, a lubrication system is preferably required when the engine on LPG fuel. The system further comprises a oil tank (50), a vacuum operated ON / OFF valve (55), an oil flow control unit (62). The oil tank (50) is connected to the vacuum operated valve by a oil hose (70) and the vacuum valve is connected the engine, the oil flow control unit (62) and the mixer unit (43) by oil hose (70). Working of the System: The accompanying drawings illustrates a typical layout of a two stoke marine (outboard) engine run on bi -fuel. In this system liquid LPG is withdrawn from the replaceable LPG cylinder (10) by the cylinder valve (12) through its dip tube which is dipped in liquid LPG. The liquid is supplied through the valve adapter (23) to the LPG vaporizer (25) by an LPG hose (30). The liquid LPG is converted into vapour in the vapourizer due to the heat of the circulating water from the engine jacket connected to the vaporizer by water circulation hoses shown in Fig. 1. The LPG vapour is then supplied to the engine due to engine suction created by the moving pistons of the engine. The amount of LPG supplied is controlled by the gas flow control unit (36) fitted on the vapourizer. The gas and the air entering into the engine are mixed together in the gas - air mixer (43) fitted on the intake side of the carburetor from where the said mixture of gas and air is supplied to the engine for combustion and for generating the required power. In case of a two stroke engine, a lubrication system is required when the engine is run on LPG fuel. The oil is stored in a separate oil tank (50). It is supplied to the engine through a vacuum operated ON / OFF valve (55) and a flow control unit (62) connected through by oil hoses (70). One end of vacuum operated valve (55) is connected to the engine manifold for sensing vacuum. 6 As soon as engine starts, the vacuum operated valve (55) opens and allows the oil to enter from the tank (50) into the engine. The quantity of the oil being fed to the engine is controlled by an oil flow control unit (62). The description and the operation of the two-stroke engine (outboard) engine running on bi-fuel are only by way of an example. It will be appreciated that other improvements and modifications of such engines, which are well within the knowledge of any person skilled in the art are also intended to be covered within the scope of the present invention. 7 WE CLAIM: 1. A LPG kit fitted with a liquid withdrawal system for use in marine engines comprising a replaceable LPG cylinder (10) , a liquid withdrawal cylinder valve (12) fitted at the neck of said LPG cylinder, a dip tube (15) being fixed at the lower end of said liquid withdrawal cylinder valve which enters said LPG cylinder almost upto its bottom and remains dipped in liquid LPG; a valve adaptor (23) being fitted on said cylinder valve provided with a knob to turn on or off the LPG supply to the system, a LPG regulator (25) being connected to said LPG valve adaptor (23) with a hose tube (30), a gas flow control valve (36) being fitted to the outlet of said regulator , a gas- air mixer unit (43) being fitted on the carburetor air intake side adjacent to the air box of an engine (45), said mixture unit (43) and said gas flow control unit being connected by a LPG hose (48); said system includes an oil tank (50), a vacuum operated on / off valve (55) and an oil flow control unit (62); said oil tank (50) being connected to said vacuum operated valve by an oil hose (70), said vacuum operated valve (55) being connected to said engine, said engine oil flow unit (62) and said mixer unit (43) by said oil hoses. 2. A LPG kit fitted with a liquid withdrawal system as claimed in Claim 1 wherein said LPG cylinder valve essentially comprises a metal forged body which accommodates a valve assembly substantially similar to a self closing valve, said metal forged body is having a lower stub portion provided with taper threads suitable for making a leak proof joint with threads of the bungs of replaceable LPG cylinder, and also accommodate a excess flow check valve and a dip tube, the upper portion or collar of said valve is machined to hold a LPG valve adaptor. 3. A LPG kit fitted with liquid withdrawal system as claimed in Claim 2 wherein said caller is provided with a seal and an internal profile to make it leak proof tight joint with said adaptor. 4. A LPG kit fitted with liquid withdrawal system as claimed in Claim 2 or 3 wherein a groove is provided on said caller of the valve in which a pawl or locking balls of the adaptor mesh for retaining said adaptor rigidly on said valve. 8 5. A LPG kit fitted with liquid withdrawal system as claimed in Claim 1 wherein a metallic tube is fixed at the bottom of said valve, said valve body is fitted to tube joint to make leak proof so that LPG vapour does not escape out of the tank and the length of the tube is maintained such that it remains just above the inner bottom surface of LPG cylinder to facilitate maximum liquid withdrawal. 6. A LPG kit fitted with liquid withdrawal system as claimed in Claim 1 is adapted for 2 / 4 stroke marine engine running on bi-fuel. 7. A LPG kit fitted with liquid withdrawal system as claimed in Claim 1 wherein said LPG cylinder contains liquid LPG maximum upto 80% of its volume. 8. A LPG kit fitted with liquid withdrawal system as claimed in any one of the preceding claims wherein said engine is fitted with a jacket and which is connected by hot water circulation hoses to the vapouriser. 9. A LPG kit fitted with liquid withdrawal system as claimed in Claim 8 wherein vaporizer vacuum port and engine manifold are connected by a vacuum hose. 10. A LPG kit fitted with liquid withdrawal system for use in marine engines substantially as herein described and as illustrated in the accompanying drawings. Dated this 18th the day of July 2007. 9

Full Text

FORM-2
THE PATENTS ACT, 1970 (39 OF 1970)
AND
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10, Rule 13)
TITLE
LPG KIT WITH LIQUID LPG WITHDRAWAL SYSTEM FOR MARINE ENGINES
APPLICANT
Vanaz Engineers Ltd. of 85 /1 Paud Road, Pune - 411 029, Maharastra, India, an Indian Company Registered under the provisions of the Companies Act, 1956
The following specification particularly describes the invention and the manner in
which it is to be performed

TITLE
LPG KIT WITH LIQUID LPG WITHDRAWAL SYSTEM FOR MARINE ENGINES
Field of invention
The present invention relates to a LPG kit for marine engines used in various watercrafts and marine vessels. This invention particularly relates to a LPG kit with liquid LPG withdrawal system to run gasoline marine engines on Liquefied Petroleum Gas (LPG). Such engines are ordinarily used in fishing boats and for other marine vessels for different applications. LPG kit of the present invention is suitable for 2/4 stroke single or multi cylinder outboard motors and other engines for marine applications.
Prior Art
At present the boats used in fishing along the Indian coastal areas / belt are mostly powered with 2 stroke single or multi cylinder or even 4 stroke single or multi cylinder outboard motors or engines of various makes ranging from 9.9 HP to 110 HP motors. Out of this range, more popularly used outboard motors are of capacities between 9.9 HP to 40 HP. Even in the above range, the majority of outboard motors are of capacity 9.9 HP to 25 HP engines. All these engines are basically Spark Ignition (SI) type engines which run on conventional fuels like petrol or kerosene or petrol start and kerosene run. Due to the extensive use of these conventional fueled engines, the pollution levels particularly along the coastal zones are regularly increasing to a level which is much higher than the expected level. Moreover, the numbers of such motors are rapidly increasing day by day, thus increasing the pollution to alarming high level causing serious threats and health hazards. This is a matter of great concern. Further, the cost of running these engines on conventional fuels is considerably high. As a result reductions of pollutant emission level and cost of fuel have become important issues and considered to be required immediate attention.
1

Invention
To avoid the aforesaid drawbacks a great deal of research works have been done particularly in the automotive sector for utilizing alternative fuels like LPG and CNG for 2, 3 and 4 wheeler, commercial vehicles and heavy commercial vehicles which are powered by 2 stroke or 4 stroke single and / or multi cylinder engines.
The use of LPG for outboard motors and other marine engines has not been successfully developed till date upto the expectation and / or desired requirement of the users. The known kits used for conversion of marine engines employing LPG vapour withdrawal system. In such system LPG is withdrawn from the cylinder in gaseous state, the vaporization takes place in the cylinder itself. As the LPG consumption increases due to the higher fuel demand from the Engine, the vaporization rate of liquid LPG inside the cylinder steadily increases, due to this the LPG cylinder temperature reduces to such an extent that it goes even below zero degree, resulting in to reduction in supply of gaseous LPG from the cylinder and further stopping of Engine itself. Such systems therefore either restrain the engine power capacity or necessitate the use of large capacity or multiple cylinder banks. Multiple cylinders occupy a major space in rather small fishing vessels and also add unnecessary weight to the boat. These ultimately result loss of speed, less storage space for the catch and requires more fuel to run the engine.
Moreover, handling of large capacity or multiple LPG cylinders become inconvenient and difficult. Improper placement of large capacity cylinders sometimes lead to uneven distribution of load and often causing toppling of the vessels in the wavy sea.
One of the objects of the present invention is to mitigate the disadvantages as experienced in the prior art and as described herein above in using the known marine engines particularly for the fishing vessels. In the present invention the liquid LPG is withdrawn from the cylinder and vaporized in the Regulator/Vaporizer with the help of Hot/Warm water circulated from Engine cooling jacket. As liquid is withdrawn from the cylinder, no major vapourization takes place in cylinder itself and thus totally avoids cooling/chilling of the cylinder. This enables to get uninterrupted supply of LPG from the cylinder as per the engine demand.
2

A further object of the present invention is to provide a LPG kit with liquid LPG withdrawal system having less weight thereby enhancing the speed of the fishing boat.
A still further object of the present invention is to provide a LPG kit with liquid LPG withdrawal system having smaller dimension, thereby providing more storage space in the marine vessels namely fishing boats.
Another object of the present invention is to provide a LPG kit with liquid LPG withdrawal system which consumes less fuel for the fishing boat.
Yet another object of the present invention is to have a liquid LPG kit with liquid withdrawal LPG system for marine engines emitting less pollutant in the surrounding atmosphere, and thus reducing the health hazard.
In one embodiment of the present invention, the LPG cylinder valve withdraws liquid LPG from the cylinder and supplies it to the kit vaporizer where liquid LPG is vaporized and the liquid LPG is supplied to the engine through the gas - air mixer.
In another embodiment of the present invention, small replaceable cylinders of less weight and capacity are used for convenience since such would occupy less space and at the same time supply sufficient quantity of liquid LPG required for the optimum speed and load performance of the marine engines.
In still another embodiment of the present invention such LPG cylinders are placed on the floor of the vessel. This lowers the load and balances the centre of gravity which gives more stability of the vessel and more storage space for the catch.
In a further embodiment of the present invention, only required numbers of small LPG cylinders are used for reducing the weight of the marine vessel and such cylinders occupy less area or volume in the vessel.
One more object of the present invention is to produce comparatively smaller, lighter and more economical marine vessel, particularly suitable as fishing boat.
3

According to this invention there is provided a LPG kit fitted with a liquid withdrawal system for use in marine engines comprising a replaceable LPG cylinder for holding liquid LPG, a liquid withdrawal cylinder valve fitted at the neck of said LPG cylinder, a dip tube being fixed at the lower end of said liquid withdrawal cylinder valve, the other end of said dip tube enters into extends almost upto the inner bottom surface of said cylinder and remains dipped in liquid LPG; a valve adaptor being fitted on said cylinder valve provided with a knob to turn on or off the LPG supply to the system, a LPG regulator being connected to said LPG valve adaptor with a hose tube, a gas flow control valve being fitted to the outlet of said regulator , a gas- air mixer unit being fitted on the carburetor air intake side adjacent to the air box of an engine, said mixture unit and said gas flow control unit being connected by a LPG hose ; said system includes an oil tank , a vacuum operated on / off valve and an oil flow control unit; said oil tank being connected to said vacuum operated valve by an oil hose said vacuum operated valve being connected to said engine, said engine oil flow unit and said mixer unit by said oil hoses.
In the LPG kit of the present invention there is provided a LPG cylinder valve comprising a metal forged body which accommodates a valve assembly substantially similar to a said closing valve, said metal forged body is having a lower stub portion provided with taper threads suitable for making a leak proof joint with threads of the bungs of replaceable LPG cylinder, upper portion or collar of said valve is machined to hold LPG valve adaptor. The said collar is preferably provided with a seal and internal profile to make it leak proof tight joint with said adaptor. At the lower end of the valve body and Excess Flow Check Valve is provided which goes inside the LPG Cylinder.
In the LPG kit fitted with the liquid withdrawal system of this invention is provided with a leak proof sealing arrangement with a groove on the collar of the valve in which a pawl or locking balls of the adaptor are used to mesh for retaining said adaptor rigidly on said valve. Quite often a metallic tube is fixed at the bottom of said valve body so that LPG vapour does not escape out of the tank and the length of the tube is maintained such that it remains just above the inner bottom surface of the LPG cylinder to facilitate maximum liquid withdrawal.
4

The LPG kit is preferably adapted for 2 -stroke but not particularly limited to 2 strokes marine engines running on bi-fuel where LPG cylinder contains liquid LPG maximum upto 80% of its volume.
In one of the aspect the present invention, the LPG kit is fitted with liquid withdrawal system where the hot / warm water from Engine water jacket is connected to vaporizer through the hot water circulation hoses which is used to vapourise liquid LPG to Gaseous LPG.
In another aspect of the present invention, the 2 stroke engine is provided with a lubrication system where the engine is run on LPG fuel and the oil is supplied to the engine through a vacuum operated on/off valve and flow control unit connected together by oil hose and one end of said vacuum operated valve being connected to the engine manifold for sensing vacuum.
This invention will now be described in detail with reference to the accompanying drawings wherein -
Fig.l illustrates a LPG kit with liquid withdrawal system for use in a marine engine;
and
Fig.2 illustrates the LPG cylinder used in the marine engine as shown in Fig.l.
The accompanying drawings show a 2 stroke marine engine run on bi-fuel. The system comprises a replaceable LPG cylinder (10) containing liquid LPG maximum upto 80% of its volume. A liquid withdrawal cylinder valve (12) is fitted at the neck portion of said cylinder.
A dip tube (15) is fixed at the lower end of the valve which enters the LPG cylinder and extends almost upto its inner bottom surface so as to be dipped in liquid LPG. An adaptor (23) is fitted on the cylinder valve which is provided with a knob to turn on and off the supply of LPG to the system. A LPG vaporizer (25) is connected to said LPG valve adaptor (23) by a hose tube (30). A gas flow control valve (36) is fitted to the outlet of the vaporizer / regulator (40). A gas- air mixer unit (43) is fitted on the carburetor air intake side
5

placed adjacent to the air box of the engine (45). The mixer unit and the said gas flow control unit are connected by a LPG hose (48). The engine jacket and the vaporizer are connected by a hot water circulation hoses. Further the vaporizer vacuum port and the engine manifold are connected by a vacuum hose.
In case the system has to run on a two stoke engine, a lubrication system is preferably required when the engine on LPG fuel. The system further comprises a oil tank (50), a vacuum operated ON / OFF valve (55), an oil flow control unit (62). The oil tank (50) is connected to the vacuum operated valve by a oil hose (70) and the vacuum valve is connected the engine, the oil flow control unit (62) and the mixer unit (43) by oil hose (70).
Working of the System:
The accompanying drawings illustrates a typical layout of a two stoke marine (outboard) engine run on bi -fuel. In this system liquid LPG is withdrawn from the replaceable LPG cylinder (10) by the cylinder valve (12) through its dip tube which is dipped in liquid LPG. The liquid is supplied through the valve adapter (23) to the LPG vaporizer (25) by an LPG hose (30). The liquid LPG is converted into vapour in the vapourizer due to the heat of the circulating water from the engine jacket connected to the vaporizer by water circulation hoses shown in Fig. 1.
The LPG vapour is then supplied to the engine due to engine suction created by the moving pistons of the engine. The amount of LPG supplied is controlled by the gas flow control unit (36) fitted on the vapourizer. The gas and the air entering into the engine are mixed together in the gas - air mixer (43) fitted on the intake side of the carburetor from where the said mixture of gas and air is supplied to the engine for combustion and for generating the required power.
In case of a two stroke engine, a lubrication system is required when the engine is run on LPG fuel. The oil is stored in a separate oil tank (50). It is supplied to the engine through a vacuum operated ON / OFF valve (55) and a flow control unit (62) connected through by oil hoses (70). One end of vacuum operated valve (55) is connected to the engine manifold for sensing vacuum.
6

As soon as engine starts, the vacuum operated valve (55) opens and allows the oil to enter from the tank (50) into the engine. The quantity of the oil being fed to the engine is controlled by an oil flow control unit (62).
The description and the operation of the two-stroke engine (outboard) engine running on bi-fuel are only by way of an example. It will be appreciated that other improvements and modifications of such engines, which are well within the knowledge of any person skilled in the art are also intended to be covered within the scope of the present invention.
7

WE CLAIM:
1. A LPG kit fitted with a liquid withdrawal system for use in marine engines comprising a replaceable LPG cylinder (10) , a liquid withdrawal cylinder valve (12) fitted at the neck of said LPG cylinder, a dip tube (15) being fixed at the lower end of said liquid withdrawal cylinder valve which enters said LPG cylinder almost upto its bottom and remains dipped in liquid LPG; a valve adaptor (23) being fitted on said cylinder valve provided with a knob to turn on or off the LPG supply to the system, a LPG regulator (25) being connected to said LPG valve adaptor (23) with a hose tube (30), a gas flow control valve (36) being fitted to the outlet of said regulator , a gas- air mixer unit (43) being fitted on the carburetor air intake side adjacent to the air box of an engine (45), said mixture unit (43) and said gas flow control unit being connected by a LPG hose (48); said system includes an oil tank (50), a vacuum operated on / off valve (55) and an oil flow control unit (62); said oil tank (50) being connected to said vacuum operated valve by an oil hose (70), said vacuum operated valve (55) being connected to said engine, said engine oil flow unit (62) and said mixer unit (43) by said oil hoses.
2. A LPG kit fitted with a liquid withdrawal system as claimed in Claim 1 wherein said LPG cylinder valve essentially comprises a metal forged body which accommodates a valve assembly substantially similar to a self closing valve, said metal forged body is having a lower stub portion provided with taper threads suitable for making a leak proof joint with threads of the bungs of replaceable LPG cylinder, and also accommodate a excess flow check valve and a dip tube, the upper portion or collar of said valve is machined to hold a LPG valve adaptor.
3. A LPG kit fitted with liquid withdrawal system as claimed in Claim 2 wherein said caller is provided with a seal and an internal profile to make it leak proof tight joint with said adaptor.
4. A LPG kit fitted with liquid withdrawal system as claimed in Claim 2 or 3 wherein a groove is provided on said caller of the valve in which a pawl or locking balls of the adaptor mesh for retaining said adaptor rigidly on said valve.
8

5. A LPG kit fitted with liquid withdrawal system as claimed in Claim 1 wherein a metallic
tube is fixed at the bottom of said valve, said valve body is fitted to tube joint to make
leak proof so that LPG vapour does not escape out of the tank and the length of the tube is
maintained such that it remains just above the inner bottom surface of LPG cylinder to
facilitate maximum liquid withdrawal.
6. A LPG kit fitted with liquid withdrawal system as claimed in Claim 1 is adapted for 2 / 4 stroke marine engine running on bi-fuel.
7. A LPG kit fitted with liquid withdrawal system as claimed in Claim 1 wherein said LPG cylinder contains liquid LPG maximum upto 80% of its volume.
8. A LPG kit fitted with liquid withdrawal system as claimed in any one of the preceding claims wherein said engine is fitted with a jacket and which is connected by hot water circulation hoses to the vapouriser.
9. A LPG kit fitted with liquid withdrawal system as claimed in Claim 8 wherein vaporizer vacuum port and engine manifold are connected by a vacuum hose.
10. A LPG kit fitted with liquid withdrawal system for use in marine engines substantially as herein described and as illustrated in the accompanying drawings.
Dated this 18th the day of July 2007.

9

Documents:

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Patent Number

268660

Indian Patent Application Number

1420/MUM/2007

PG Journal Number

37/2015

Publication Date

11-Sep-2015

Grant Date

10-Sep-2015

Date of Filing

24-Jul-2007

Name of Patentee

VANAZ ENGINEERS LTD

Applicant Address

85/1 PAUD ROAD, PUNE

Inventors:

#	Inventor's Name	Inventor's Address
1	SARVATE SURESH RAGHUNATH	VANAZ ENGINEERS LTD, 85/1 PAUD ROAD, PUNE 411029

PCT International Classification Number

B60K1/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA