Title of Invention	CONTROLLING VAPOR EMISSION IN A SMALL ENGINE FUEL TANK SYSTEM
Abstract	A fuel vapor emission system for small engine gas tank which does not require redesign or retooling for manufacturing of the tank. A new filler tube has the lower end positioned to cause fuel to rise rapidly in the tube before the tank is full, signaling the operator to stop refueling and maintain a vapor dome in the tank when the filler cap is replaced. A vapor vent valve is disposed in a separate access opening and includes a float operated rollover valve. The vent valve opens when a predetermined positive pressure is reached in the tank; and, a reverse flow vacuum relief valve is disposed in the vent valve. The outlet of the vent valve is intended to be connected to either a storage canister or the engine air inlet.

Title of Invention

CONTROLLING VAPOR EMISSION IN A SMALL ENGINE FUEL TANK SYSTEM

Abstract

A fuel vapor emission system for small engine gas tank which does not require redesign or retooling for manufacturing of the tank. A new filler tube has the lower end positioned to cause fuel to rise rapidly in the tube before the tank is full, signaling the operator to stop refueling and maintain a vapor dome in the tank when the filler cap is replaced. A vapor vent valve is disposed in a separate access opening and includes a float operated rollover valve. The vent valve opens when a predetermined positive pressure is reached in the tank; and, a reverse flow vacuum relief valve is disposed in the vent valve. The outlet of the vent valve is intended to be connected to either a storage canister or the engine air inlet.

Full Text	WO 2006/067586 PCT/IB2005/003824 TITLE OF INVENTION [0001] Controlling Vapor Emission In A Small Engine Fuel Tank System. BACKGROUND OF THE INVENTION [0002] The present invention relates to fuel tank systems for small engines of the type employed for portable appliances such as portable power generating sets, garden tractors, lawn mowers and other such devices where the fuel tank is either mounted on the engine or closely adjacent thereto. Fuel tanks of this type are typically refueled by removing the filler cap and pouring fuel from a container having a pouring spout, or by pouring from a container and using a funnel. [0003] Small engine fuel systems have recently been subjected to mandated requirements for fuel vapor emission control and it has been required to prevent vapor emission from the tank during operation and when the engine is not operating. [0004] Heretofore small engine fuel systems have often employed a tank having an open vent in the filler cap for providing make-up air in the tank as fuel was withdrawn but which permitted escape of fuel vapor to the atmosphere. [0005] In order to meet the requirement that a fuel tank for a small engine not emit fuel vapor, the filler cap must be sealed to prevent fuel vapor emission. If the filler cap is sealed then other provisions must be made for admitting make up air to the tank during engine operation. Furthermore, provisions must be made for overpressure relief. Thus, it has been desired to find a way or means of sealing a small engine fuel tank, yet provide for make-up air and over pressure relief and to do so in a cost-effective manner without requiring redesign or retooling of the tanks. [0006] BRIEF SUMMARY OF THE INVENTION [0007] The present invention provides a fuel vapor emission control valve in the tank which controls the flow of fuel vapor through a passage extending exteriorly of the tank and also includes a rollover or upset valve preventing liquid -1 - CONFIRMATION COPY WO 2006/067586 PCT/IB2005/003824 fuel from escaping the tank. The vapor vent valve includes a head valve which retains the vapor in the tank until a predetermined positive pressure is reached; and, the vent valve also includes a reverse flow check valve permitting make-up air to enter the tank as fuel is withdrawn or upon a sub-atmospheric pressure occurring in the tank such as, for example, by cooling of the tank. The fuel vapor vent passage may be connected externally to either a vapor storage device or the air inlet of the engine. The invention includes fitting an existing fuel tank with a filler tube extending to a predetermined level or depth in the tank to cause the fuel to rise rapidly in the filler tube upon reaching the lower end of the tube during refueling to signal the operator that tank has reached the desired fill level. This arrangement prevents overfilling and preserves a vapor dome in the tank above the liquid level of the fuel to ensure proper functioning of the vapor vent valve. BRIEF DESCRIPTION OF THE DRAWINGS [0008] FIG. 1 is a pictorial schematic showing a small engine fuel tank in cross-section with the filler tube and vapor vent valve of the present invention installed thereon; and, the connections to either a vapor storage device or alternatively the engine air inlet are shown in dashed line; [0009] FIG. 2 is an enlarged detail of the vapor vent valve of FIG. 1; [0010] FIG. 3 is an enlarged view of a portion of FIG. 2 with the vapor vent valve closed; [0011] FIG. 4 is a view similar to FIG. 3 showing the vapor vent valve opened; and, [0012] FIG. 5 is a view similar to FIG. 3 with the reverse flow valve shown open in response to a vacuum in the tank. DETAILED DESCRIPTION OF THE INVENTION [0013] Referring to FIGS. 1 and 2, the small engine fuel tank assembly of the present invention is indicated generally at 10 and includes an existing tank wall structure 12 with a new filler tube 14 having a vapor tight removable closure 16 received on the exterior end of the tube with the lower end of the tube 14 extending into the tank to a desired depth or level indicated by the reference -2- WO 2006/067586 PCT/IB2005/003824 character d. [0014] A separate access opening 18 is formed in the upper portion of the tank wall and through which is inserted a combination rollover and vapor vent valve indicated generally at 20 which has a lower housing portion 22 extending into the tank and an upper housing portion 24 with an outwardly extending flange 26 thereabout attached to the tank wall and sealed thereabout by any suitable expedient as, for example, weldment. [0015] The lower valve housing 22 has a float 28 disposed therein with a flexible valve member 30 disposed on the upper end of the float which closes in the event that fuel rises above the level d due to sloshing, overfilling or the tank becoming severely tipped or inverted, under which conditions valve member 30 seats upon a valve seat 32 formed in the upper housing 24. [0016] The valve seat 32 is formed on the lower end of a vent passage 34 which communicates with an enlarged diameter upper portion 36 which communicates with vent passage 38 which extends outwardly through attachment fitting 40 which may be formed as part of the upper housing 24. [0017] The enlarged diameter portion 36 of the vent passage has slidably received therein a valve member 42 which has a passage 44 therethrough and which has the lower surface 46 thereof configured to seat upon surface 48 formed in the upper body at the upper end of passage 34. When the valve member 42 is in the lower position shown in FIG. 3 and FIG. 5, flow through passage 34 must transit through passage 44, not the enlarged diameter passage 36. [0018] Valve member 42 has formed therein a valving chamber 50 with a valve seat 52 formed in an inverted position therein on the lower end of the flow passage 54 which communicates with vent passage 38. Chamber 50 has received therein a check valve member 56 which may be in the form of a relatively light weight ball which may be formed of plastic and which seats on valve set 52 and closes passage 54 when a positive pressure exists in the fuel tank. [0019] With reference to FIGS. 3, 4 and 5, it will be seen that the enlarged diameter 36, in which valve member 42 slides, has slots or passages 60 formed therein to permit passage of vapors for communication with passage 38 when the -3- WO 2006/067586 PCT/IB2005/003824 valve member 42 is in the upward position and not seated on the seating surface 48. [0020] In operation, with the filler cap 16 removed and the tank refueled through filler tube 14, when the level of the fuel reaches the height d, with continued filling a fuel level increases rapidly in the tube 14 giving visual notice to the operator that the tank has reached the desired fill level. After refueling when the filler cap is replaced, the tank is sealed except for vent passage 38 so long as the tank is in the upright position or is not substantially tilted so as to cause float valve 30 to close on valve seat 32. [0021] If the vapor pressure in the tank is substantially atmospheric or only slightly above, the valve member 42 is seated on seating surface 48 and only a small amount of vapor can enter the valving chamber 50 and the flow therethrough passage 44 causes ball valve 56 to seat against the seating surface 52 as shown in FIG. 3 preventing escape of vapor. As the vapor pressure increases, valve member 42 is moved upwardly to the position as shown in FIG. 4 permitting passage of vapor through passages 60 into the passage 38; and, as shown in FIG. 1, to either a storage device 70 or to the engine air inlet 72. [0022] In the event that the tank is suddenly cooled and the vapor pressure in the tank drops below atmospheric, creating a vacuum in the tank, ball valve member 56 drops from its upper seat 52 allowing make-up air to enter the tank. It will be understood that this condition can also occur as fuel is withdrawn from the tank. [0023] The present invention thus provides a simple, relatively low cost and easy to install technique for modifying an existing small engine fuel tank for control of fuel vapor emissions to meet current requirements. The invention combines a filler tube extending in the tank to maintain a vapor dome with a vapor vent control/rollover valve to prevent fuel vapor from escaping to the atmosphere upon connection to either a storage device or the engine air inlet. [0024] Although the invention has hereinabove been described with respect to the illustrated embodiments, it will be understood that the invention is capable of modification and variation and is limited only by the following claims. -4- WO 2006/067586 PCT/IB2005/003824 What is claimed is: 1. A small engine fuel tank vapor emission control system comprising: (a) a fuel tank (12) with a substantially vapor impermeable wall structure for use with a small engine; (b) a vapor vent valve (20) disposed to receive vapor from within the tank and including a vent outlet (38, 34), wherein said vent valve is operable for closing the vent outlet when the fuel level rises to a predetermined level in the tank; (c) a filler tube (14) disposed through a wall of the tank, with the lower end of the tube located at a depth (d) in the tank so as to be closed by liquid fuel rising in the tank during refueling before the vapor vent valve closes, thereby defining a vapor dome in the tank; and, (d) a normally closed valve (46) disposed to block vapor flow in said vent outlet and operable to open at a predetermined positive vapor pressure in the tank. 2. The system defined in claim 1, wherein said head valve includes a bleed port bypassing said valve for permitting a limited flow when said valve is in the normally closed position. 3. The system defined in claim 1, wherein said head valve includes a vacuum relief valve (56) operable upon occurrence of sub-atmospheric pressure in the tank to permit reverse flow of vapor from the canister to the tank. 4. The system defined in claim 1, wherein said vent valve includes a moveable poppet (42) with a vacuum relief valve disposed therethrough for reverse flow. 5. The system defined in claim 4, wherein the vacuum relief valve includes a spherical valve member (56) moveable with respect to a valve seat formed on said poppet. -5- WO 2006/067586 PCT/IB2005/003824 6. The system defined in claim 1, wherein said vent outlet is connected to one of (a) a vapor storage device (70) and (b) the engine air inlet (72). 7. A method of controlling vapor emission from a small engine fuel tank comprising: (a) forming a fuel tank (12) having a wall structure substantially impermeable to fuel vapor; (b) disposing a vapor vent valve (20) for communicating fuel vapor in the tank from the valve outlet (38) to the canister and closing the vent valve when liquid fuel in the tank reaches a predetermined level; (c) disposing a filler tube (14) through the wall structure and locating the lower end of the tube at a depth (d) in the tank so as to be closed by liquid fuel rising in the tank before the vent valve closes and defining a vapor dome in the tank; and, (d) disposing a normally closed head valve (46) in the outlet of the vent valve and preventing vapor flow to one of (a) a canister (70) and (b) the engine air inlet (72) until the vapor pressure reaches a predetermined level above atmospheric. 8. The method defined in claim 7, wherein said step of disposing a head valve includes forming a bleed passage for bypassing the head valve with a limited flow. 9. The method defined in claim 7, wherein said step of disposing a head valve includes disposing a vacuum relief valve (58) and opening the relief valve upon the occurrence of sub-atmospheric pressure in the tank and flow vapor from the canister to the tank. -6- WO 2006/067586 PCT/IB2005/003824 10. A method of controlling venting of fuel vapor in a small engine fuel tank comprising: (a) disposing a filler tube (14) through a wall of the tank and extending one end of the tube to a desired level (d) of fuel fill in the tank; (b) disposing a float operated vent valve (20) for venting vapor and responding to rising fuel level to close the vent valve and connecting the vapor outlet of the vent valve to one of (a) a storage canister and (b) the engine air inlet; and, (c) disposing a pressure relief or head valve (46) in the outlet of said vent valve and blocking vent flow therethrough at vapor pressures less than a predetermined minimum above atmospheric. 11. The method defined in claim 10, wherein said step of disposing a pressure relief valve includes disposing a vacuum relief valve (56) and permitting reverse flow upon occurrence of sub-atmospheric pressure in the tank. 12. The method defined in claim 10, wherein said step of disposing a head valve includes forming a bleed passage bypassing said head valve for limited bleed flow when the head valve is closed. 13. A system for maintaining a vapor dome in a small engine fuel tank connected to a vapor storage device comprising: (a) a filler tube (14) with one end extending to a predetermined fill depth/level (d) in the tank, and having a user operable closure (16) on an end communicating exteriorly of the tank; (b) means (38) defining a vapor vent path from the tank to the storage device; (c) pressure responsive means (46) disposed in the vent path and operable, in response to the vapor pressure in the tank remaining below a predetermined threshold, to substantially prevent vapor flow, and upon the vapor pressure in the tank reaching the threshold, to permit substantial vapor flow to the device, wherein upon removal of said closure and refueling through said tube, fuel -7- WO 2006/067586 PCT/IB2005/003824 reaching said predetermined level causes fuel to rise in said tube substantially faster than in said tank, thereby giving visual notice of fill level and preserving a vapor dome in the tank. 14. The system defined in claim 13, wherein said pressure responsive means includes a valve member (42) moveable for closing on a valve vent seat (48) to prevent vapor flow and a bleed passage bypassing said valve member for permitting limited bleed flow. 15. The system defined in claim 13, wherein said valve member has a spherical configuration. 16. The system defined in claim 13, wherein said pressure responsive means includes a pressure relief valve. 17. The system defined in claim 13, wherein said pressure relief valve includes a reverse flow vacuum relief valve (56). 18. The system defined in claim 16, further comprising a float operated valve (30) operable to block said vent path when the fuel level reaches a tank full level. 19. A method of controlling fuel vapor emission in a small engine fuel system comprising: (a) disposing a filler tube (14) on the tank with an operable closure (16) on one end and locating the end opposite said one end at a predetermined fill level/depth in the tank such that, upon reaching said level/depth (d) fuel rises faster in the tube than in the tank thereby forming a vapor dome in the tank; (b) forming a vapor vent flow path (44, 38) from the interior of the tank to the exterior thereof; and, (c) disposing a normally closed pressure responsive valve in said vent path and opening said valve when the vapor pressure in the tank -8- WO 2006/067586 PCT/IB2005/003824 reaches a predetermined level. -9- 20. The method defined in claim 19, wherein said step of forming a vapor vent flow path includes disposing a float operated valve (30) in the flow path fluidically in series in the flow path with said pressure responsive valve (46). 21. The method defined in claim 19, wherein said step of disposing a pressure responsive valve includes disposing a vacuum responsive reverse flow valve (56). 22. The method defined in claim 19, wherein said step of forming a vapor vent flow path includes attaching a vent valve over an access opening (18) in the tank. 23. The method defined in claim 19 further comprising connecting said vent path to one of (a) a storage device (70) and (b) the engine air inlet (72). A fuel vapor emission system for small engine gas tank which does not require redesign or retooling for manufacturing of the tank. A new filler tube has the lower end positioned to cause fuel to rise rapidly in the tube before the tank is full, signaling the operator to stop refueling and maintain a vapor dome in the tank when the filler cap is replaced. A vapor vent valve is disposed in a separate access opening and includes a float operated rollover valve. The vent valve opens when a predetermined positive pressure is reached in the tank; and, a reverse flow vacuum relief valve is disposed in the vent valve. The outlet of the vent valve is intended to be connected to either a storage canister or the engine air inlet.

Full Text

WO 2006/067586 PCT/IB2005/003824
TITLE OF INVENTION
[0001] Controlling Vapor Emission In A Small Engine Fuel Tank System.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to fuel tank systems for small engines of
the type employed for portable appliances such as portable power generating
sets, garden tractors, lawn mowers and other such devices where the fuel tank is
either mounted on the engine or closely adjacent thereto. Fuel tanks of this type
are typically refueled by removing the filler cap and pouring fuel from a container
having a pouring spout, or by pouring from a container and using a funnel.
[0003] Small engine fuel systems have recently been subjected to mandated
requirements for fuel vapor emission control and it has been required to prevent
vapor emission from the tank during operation and when the engine is not
operating.
[0004] Heretofore small engine fuel systems have often employed a tank
having an open vent in the filler cap for providing make-up air in the tank as fuel
was withdrawn but which permitted escape of fuel vapor to the atmosphere.
[0005] In order to meet the requirement that a fuel tank for a small engine not
emit fuel vapor, the filler cap must be sealed to prevent fuel vapor emission. If
the filler cap is sealed then other provisions must be made for admitting make up
air to the tank during engine operation. Furthermore, provisions must be made
for overpressure relief. Thus, it has been desired to find a way or means of
sealing a small engine fuel tank, yet provide for make-up air and over pressure
relief and to do so in a cost-effective manner without requiring redesign or
retooling of the tanks.
[0006]
BRIEF SUMMARY OF THE INVENTION
[0007] The present invention provides a fuel vapor emission control valve in
the tank which controls the flow of fuel vapor through a passage extending
exteriorly of the tank and also includes a rollover or upset valve preventing liquid
-1 -
CONFIRMATION COPY

WO 2006/067586 PCT/IB2005/003824
fuel from escaping the tank. The vapor vent valve includes a head valve which
retains the vapor in the tank until a predetermined positive pressure is reached;
and, the vent valve also includes a reverse flow check valve permitting make-up
air to enter the tank as fuel is withdrawn or upon a sub-atmospheric pressure
occurring in the tank such as, for example, by cooling of the tank. The fuel vapor
vent passage may be connected externally to either a vapor storage device or the
air inlet of the engine. The invention includes fitting an existing fuel tank with a
filler tube extending to a predetermined level or depth in the tank to cause the fuel
to rise rapidly in the filler tube upon reaching the lower end of the tube during
refueling to signal the operator that tank has reached the desired fill level. This
arrangement prevents overfilling and preserves a vapor dome in the tank above
the liquid level of the fuel to ensure proper functioning of the vapor vent valve.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a pictorial schematic showing a small engine fuel tank in
cross-section with the filler tube and vapor vent valve of the present invention
installed thereon; and, the connections to either a vapor storage device or
alternatively the engine air inlet are shown in dashed line;
[0009] FIG. 2 is an enlarged detail of the vapor vent valve of FIG. 1;
[0010] FIG. 3 is an enlarged view of a portion of FIG. 2 with the vapor vent
valve closed;
[0011] FIG. 4 is a view similar to FIG. 3 showing the vapor vent valve opened;
and,
[0012] FIG. 5 is a view similar to FIG. 3 with the reverse flow valve shown
open in response to a vacuum in the tank.
DETAILED DESCRIPTION OF THE INVENTION
[0013] Referring to FIGS. 1 and 2, the small engine fuel tank assembly of the
present invention is indicated generally at 10 and includes an existing tank wall
structure 12 with a new filler tube 14 having a vapor tight removable closure 16
received on the exterior end of the tube with the lower end of the tube 14
extending into the tank to a desired depth or level indicated by the reference
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WO 2006/067586 PCT/IB2005/003824
character d.
[0014] A separate access opening 18 is formed in the upper portion of the tank
wall and through which is inserted a combination rollover and vapor vent valve
indicated generally at 20 which has a lower housing portion 22 extending into the
tank and an upper housing portion 24 with an outwardly extending flange 26
thereabout attached to the tank wall and sealed thereabout by any suitable
expedient as, for example, weldment.
[0015] The lower valve housing 22 has a float 28 disposed therein with a
flexible valve member 30 disposed on the upper end of the float which closes in
the event that fuel rises above the level d due to sloshing, overfilling or the tank
becoming severely tipped or inverted, under which conditions valve member 30
seats upon a valve seat 32 formed in the upper housing 24.
[0016] The valve seat 32 is formed on the lower end of a vent passage 34
which communicates with an enlarged diameter upper portion 36 which
communicates with vent passage 38 which extends outwardly through attachment
fitting 40 which may be formed as part of the upper housing 24.
[0017] The enlarged diameter portion 36 of the vent passage has slidably
received therein a valve member 42 which has a passage 44 therethrough and
which has the lower surface 46 thereof configured to seat upon surface 48 formed
in the upper body at the upper end of passage 34. When the valve member 42 is
in the lower position shown in FIG. 3 and FIG. 5, flow through passage 34 must
transit through passage 44, not the enlarged diameter passage 36.
[0018] Valve member 42 has formed therein a valving chamber 50 with a
valve seat 52 formed in an inverted position therein on the lower end of the flow
passage 54 which communicates with vent passage 38. Chamber 50 has
received therein a check valve member 56 which may be in the form of a
relatively light weight ball which may be formed of plastic and which seats on
valve set 52 and closes passage 54 when a positive pressure exists in the fuel
tank.
[0019] With reference to FIGS. 3, 4 and 5, it will be seen that the enlarged
diameter 36, in which valve member 42 slides, has slots or passages 60 formed
therein to permit passage of vapors for communication with passage 38 when the
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WO 2006/067586 PCT/IB2005/003824
valve member 42 is in the upward position and not seated on the seating surface
48.
[0020] In operation, with the filler cap 16 removed and the tank refueled
through filler tube 14, when the level of the fuel reaches the height d, with
continued filling a fuel level increases rapidly in the tube 14 giving visual notice to
the operator that the tank has reached the desired fill level. After refueling when
the filler cap is replaced, the tank is sealed except for vent passage 38 so long as
the tank is in the upright position or is not substantially tilted so as to cause float
valve 30 to close on valve seat 32.
[0021] If the vapor pressure in the tank is substantially atmospheric or only
slightly above, the valve member 42 is seated on seating surface 48 and only a
small amount of vapor can enter the valving chamber 50 and the flow
therethrough passage 44 causes ball valve 56 to seat against the seating surface
52 as shown in FIG. 3 preventing escape of vapor. As the vapor pressure
increases, valve member 42 is moved upwardly to the position as shown in FIG. 4
permitting passage of vapor through passages 60 into the passage 38; and, as
shown in FIG. 1, to either a storage device 70 or to the engine air inlet 72.
[0022] In the event that the tank is suddenly cooled and the vapor pressure in
the tank drops below atmospheric, creating a vacuum in the tank, ball valve
member 56 drops from its upper seat 52 allowing make-up air to enter the tank. It
will be understood that this condition can also occur as fuel is withdrawn from the
tank.
[0023] The present invention thus provides a simple, relatively low cost and
easy to install technique for modifying an existing small engine fuel tank for
control of fuel vapor emissions to meet current requirements. The invention
combines a filler tube extending in the tank to maintain a vapor dome with a vapor
vent control/rollover valve to prevent fuel vapor from escaping to the atmosphere
upon connection to either a storage device or the engine air inlet.
[0024] Although the invention has hereinabove been described with respect to
the illustrated embodiments, it will be understood that the invention is capable of
modification and variation and is limited only by the following claims.
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WO 2006/067586 PCT/IB2005/003824
What is claimed is:
1. A small engine fuel tank vapor emission control system comprising:
(a) a fuel tank (12) with a substantially vapor impermeable wall
structure for use with a small engine;
(b) a vapor vent valve (20) disposed to receive vapor from within the
tank and including a vent outlet (38, 34), wherein said vent valve is
operable for closing the vent outlet when the fuel level rises to a
predetermined level in the tank;
(c) a filler tube (14) disposed through a wall of the tank, with the lower
end of the tube located at a depth (d) in the tank so as to be closed
by liquid fuel rising in the tank during refueling before the vapor vent
valve closes, thereby defining a vapor dome in the tank; and,
(d) a normally closed valve (46) disposed to block vapor flow in said
vent outlet and operable to open at a predetermined positive vapor
pressure in the tank.

2. The system defined in claim 1, wherein said head valve includes a bleed
port bypassing said valve for permitting a limited flow when said valve is in
the normally closed position.
3. The system defined in claim 1, wherein said head valve includes a vacuum
relief valve (56) operable upon occurrence of sub-atmospheric pressure in
the tank to permit reverse flow of vapor from the canister to the tank.
4. The system defined in claim 1, wherein said vent valve includes a
moveable poppet (42) with a vacuum relief valve disposed therethrough for
reverse flow.
5. The system defined in claim 4, wherein the vacuum relief valve includes a
spherical valve member (56) moveable with respect to a valve seat formed
on said poppet.
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WO 2006/067586 PCT/IB2005/003824
6. The system defined in claim 1, wherein said vent outlet is connected to
one of (a) a vapor storage device (70) and (b) the engine air inlet (72).
7. A method of controlling vapor emission from a small engine fuel tank
comprising:

(a) forming a fuel tank (12) having a wall structure substantially
impermeable to fuel vapor;
(b) disposing a vapor vent valve (20) for communicating fuel vapor in
the tank from the valve outlet (38) to the canister and closing the
vent valve when liquid fuel in the tank reaches a predetermined
level;
(c) disposing a filler tube (14) through the wall structure and locating
the lower end of the tube at a depth (d) in the tank so as to be
closed by liquid fuel rising in the tank before the vent valve closes
and defining a vapor dome in the tank; and,
(d) disposing a normally closed head valve (46) in the outlet of the vent
valve and preventing vapor flow to one of (a) a canister (70) and (b)
the engine air inlet (72) until the vapor pressure reaches a
predetermined level above atmospheric.

8. The method defined in claim 7, wherein said step of disposing a head
valve includes forming a bleed passage for bypassing the head valve with
a limited flow.
9. The method defined in claim 7, wherein said step of disposing a head
valve includes disposing a vacuum relief valve (58) and opening the relief
valve upon the occurrence of sub-atmospheric pressure in the tank and
flow vapor from the canister to the tank.
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WO 2006/067586 PCT/IB2005/003824
10. A method of controlling venting of fuel vapor in a small engine fuel tank
comprising:
(a) disposing a filler tube (14) through a wall of the tank and extending
one end of the tube to a desired level (d) of fuel fill in the tank;
(b) disposing a float operated vent valve (20) for venting vapor and
responding to rising fuel level to close the vent valve and connecting
the vapor outlet of the vent valve to one of (a) a storage canister
and (b) the engine air inlet; and,
(c) disposing a pressure relief or head valve (46) in the outlet of said
vent valve and blocking vent flow therethrough at vapor pressures
less than a predetermined minimum above atmospheric.

11. The method defined in claim 10, wherein said step of disposing a pressure
relief valve includes disposing a vacuum relief valve (56) and permitting
reverse flow upon occurrence of sub-atmospheric pressure in the tank.
12. The method defined in claim 10, wherein said step of disposing a head
valve includes forming a bleed passage bypassing said head valve for
limited bleed flow when the head valve is closed.
13. A system for maintaining a vapor dome in a small engine fuel tank
connected to a vapor storage device comprising:

(a) a filler tube (14) with one end extending to a predetermined fill
depth/level (d) in the tank, and having a user operable closure (16)
on an end communicating exteriorly of the tank;
(b) means (38) defining a vapor vent path from the tank to the storage
device;
(c) pressure responsive means (46) disposed in the vent path and
operable, in response to the vapor pressure in the tank remaining
below a predetermined threshold, to substantially prevent vapor
flow, and upon the vapor pressure in the tank reaching the
threshold, to permit substantial vapor flow to the device, wherein
upon removal of said closure and refueling through said tube, fuel
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WO 2006/067586 PCT/IB2005/003824
reaching said predetermined level causes fuel to rise in said tube
substantially faster than in said tank, thereby giving visual notice of
fill level and preserving a vapor dome in the tank.
14. The system defined in claim 13, wherein said pressure responsive means
includes a valve member (42) moveable for closing on a valve vent seat
(48) to prevent vapor flow and a bleed passage bypassing said valve
member for permitting limited bleed flow.
15. The system defined in claim 13, wherein said valve member has a
spherical configuration.
16. The system defined in claim 13, wherein said pressure responsive means
includes a pressure relief valve.
17. The system defined in claim 13, wherein said pressure relief valve includes
a reverse flow vacuum relief valve (56).
18. The system defined in claim 16, further comprising a float operated valve
(30) operable to block said vent path when the fuel level reaches a tank full
level.
19. A method of controlling fuel vapor emission in a small engine fuel system
comprising:

(a) disposing a filler tube (14) on the tank with an operable closure (16)
on one end and locating the end opposite said one end at a
predetermined fill level/depth in the tank such that, upon reaching
said level/depth (d) fuel rises faster in the tube than in the tank
thereby forming a vapor dome in the tank;
(b) forming a vapor vent flow path (44, 38) from the interior of the tank
to the exterior thereof; and,
(c) disposing a normally closed pressure responsive valve in said vent
path and opening said valve when the vapor pressure in the tank
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WO 2006/067586 PCT/IB2005/003824
reaches a predetermined level.
-9-
20. The method defined in claim 19, wherein said step of forming a vapor vent
flow path includes disposing a float operated valve (30) in the flow path
fluidically in series in the flow path with said pressure responsive valve
(46).
21. The method defined in claim 19, wherein said step of disposing a pressure
responsive valve includes disposing a vacuum responsive reverse flow
valve (56).
22. The method defined in claim 19, wherein said step of forming a vapor vent
flow path includes attaching a vent valve over an access opening (18) in
the tank.
23. The method defined in claim 19 further comprising connecting said vent
path to one of (a) a storage device (70) and (b) the engine air inlet (72).

A fuel vapor emission system for small engine gas tank which does not require redesign
or retooling for manufacturing of the tank. A new filler tube has the lower end
positioned to cause fuel to rise rapidly in the tube before the tank is full, signaling the
operator to stop refueling and maintain a vapor dome in the tank when the filler cap is
replaced. A vapor vent valve is disposed in a separate access opening and includes a
float operated rollover valve. The vent valve opens when a predetermined positive
pressure is reached in the tank; and, a reverse flow vacuum relief valve is disposed in
the vent valve. The outlet of the vent valve is intended to be connected to either a
storage canister or the engine air inlet.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=OCJL4Mj8U6bue7cCLNopoQ==&loc=wDBSZCsAt7zoiVrqcFJsRw==

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Patent Number

278374

Indian Patent Application Number

1919/KOLNP/2007

PG Journal Number

53/2016

Publication Date

23-Dec-2016

Grant Date

21-Dec-2016

Date of Filing

29-May-2007

Name of Patentee

EATON CORPORATION

Applicant Address

EATON CENTER 1111 SUPERIOR AVENUE CLEVELAND, OHIO

Inventors:

#	Inventor's Name	Inventor's Address
1	MILLS, VAUGHN	14196 FAIRWAY DRIVE, CHELSA, MICHIGAN 48118-9556

PCT International Classification Number

B60K 15/035

PCT International Application Number

PCT/IB2005/003824

PCT International Filing date

2005-12-19

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	11/017,584	2004-12-20	U.S.A.