& ¥ AT WKλ I j VE EMISSIONS

[001] This application claims the benefit of Unites Slates Provisional Patent

Application 60/791,324 filed o.n April 12, 2006, the entirety of which is incorporated herein by reference. This application includes material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent disclosure-, as it appears in the Patent and Trademark Office files or records, foul otherwise reserves all copyright riεbts whatsoever.

£002} The present invention .relates to the field of fuel vapor emissions systems for engines and more particularly to a fuel tank assembly for controlling evaporative emissions.

[003] Evaporative emissions systems and the use of carbon or charcoal canisters have been nseά in combination wills automotive engines and fuel tanks, However, new regulations have propelled the need for evaporative emissions control systems for small utility engines. Typically, these small utility engines and their associated gas tank have confined locations and dimensions forcing most of the components and hnes of an evaporative emissions system to be exposed. Such exposure is both unsightly and problematic as such vaives, components and lines are subject to damage.

[(KH] A typical emission control system 10O ₁ as seen in Figure IA, for a small

utility ersgrne assists of a fuel tank 102 which stores a Cue! 104, such as gasohne, and mates with a sealed cap 10S, The fuel tank 102 contains fuel which during operation of the sogme is fed through use I IS to a carburetor 120. The (low of fuel along use 1 18 may be controlled by a fuel shutoff valve (not shown). Attached to the tank 102 is a valve 105 _> such as a slant valve, which allows emission vapors to escape the tank 102, as pressure in the tank 102 increases, to a charcoal eanisier 125 through ime .107, The eharcoa! eaiisster 125 receives and treats the evaporative emissions. Upon starting the utility engine, suction is created drawing ouiside air in through vent 1.22 and thus purging the charcoal of the accumulated hydrocarbons and pulling the evaporative emissions within the charcoal canister 125 through line 124 into carburetor !2Ci where the evaporative emissions and hydrocarbons can be burned, Afier the engine is shut off the charco-al canister 125 continues to receive and treat the evaporative emissions from iank 102 until the engme is started again and the evaporative emissions and hydrocarbons are purged from the canister 125, drawn into and burned by carburetor 120,

[005] As seen in Figure IB, a generator 101 is depicled which incorporates, a known evaporative emissions system which exposes the valve 1(15 and the evaporative emissions line 10? leading to charcoal canister 125. On or cear the top surface of the fuel tank 102 is an opening 110 for receiving a sealed cap. Additionally, valve 105 rnaies with fuel tank 102 si a position on a top ^surface of die fuel tank 102, The valve 105 is exposed creating an unsightly appearance for

industrial design as well as exposing the valve 105 to possible damage. Furthers

the evaporative emissions line 10? runs along the top, down the side and along the end of fuel tank 102 before traveling down the frame 103 of the generator 101

before finally connecting to canister 125, Both the valve 105 and line 107 are- susceptible to damage and create an urssighuy appearance. Therefore, what is seeded ss an evaporative emissions system which provides a compact, cost effective- and easy to manufacture design while reducing the unsightly appearance and exposure of the evaporative emissions valve and lines.

The present invention provides an evaporative emissions fuel system for a general-purpose engine which overcomes the obstacles described above by providing a system with a fuel tank, a canister which absorbs fuel vapor from the fuel tank, a carburetor communicating with the fuel vapor frorn the caster and communicating with the foe! from the fuel tank; a valve assembly located within the fuel tank for receiving the fuel vapor from within the fuel tank and communicating the foe! vapor to the canaster; and the valve assembly comprising a vaive opening for receiving fuei vapor and a float responsive to the fuel within the tank for sealing the vaive opening when the fuei wilhsn the tank is at. a fuel level capable of entering the vaive opening. The vaive opening may be located above a max fire! levεi of the fuel tank and below a top inferior surface of the fuel tank. The float may be attached to a sealing element which seals the valve

op&ni.ng. The evsporatsve emissions fuel system may also comprise a valve

assembly brace attached to an interior surface or the tank and to the valve assembly.

Another aspect of the present mventron provides a fuel iaak assembly for a general-purpose engine comprising; a closed fuel tank having an inlet to the imenor of the tarsk, a fuel outlet, and a fuel vapor outlet; an unvsnted fuel cap receivable on the inlet for sealing the closed fuel tank; a valve assembly located wttbin the fuel tank for receiving fuel vapor from inside the fuel tank and communicaiing the fue^ vapor through the fuel vapor outlet to a canister which absorbs and treats fuel vapor; a carhurstor communicating with the fuel vapor from the easusier and communicating with the fuel from the fuel tank through the fuel outlet; and the valve assembly eomp-rhing a valve opemng for receiving fuel vapor and a float responsive to the fuel withrn the tajik for sealing the valve ope ^y ung when the fuel vvHhiri the tank ss at a fuel (eve! capable of entering the valve opemng. Further, the valve opening may be located above a max fuel level of the fuel tank arsd betow a top interior surface of the fuel tank. The float may be attached to a sealmg element which seals the valve onenms. Additionally, a valve assembly brace may bs attached to ar* interior surface of the tank arsd to the valve assembly.

Figure i A is a schematic view «f a known fuel tank and e posed evaporative emissions system;

fOO) 0] P.ngure 1 B is a side elevation, view of a generator incorporating a known aid

exposed eva.pors.tive emissions system; [00 i ll Figure 2 is a schematic view of a fuel tank and evaporative emissions system of the present invention; ((K)J 2] Figure 3 is a sectional side view of an evaporative emissions valve of the evaporative emissions system of slie present invention; [GO 131 Fi gure 4A is a front view of an alternative evaporative emissions valve wh sch could bs incorporated in the evaporative emissions- system of the present invention; i{K)H| Figure 4.8 is a side view of the alternative evaporative emissions valve depicted hi

Figure 4A; and [0015] Figure 5 is a front view of as alternative evaporative emissions vaive which could

100161 The system of the present invention will now be described in conjunction

^■ with Figures 2-5, The present invention provides as evaporative emissions system which overcomes the obstacles described above by providing ars evaporative emissions system which integrates the evaporative emissions valve and all or portions of the emissions flow line within the internal chamber of the fuel tank,

[0017] As seen in Figure 2, the evaporative emissions system 200 of the present invention includes a gas tank 202 which is used to house or contain a fuel 204

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such as gasoline, The fuel tank 202 mates with a fill cap 2C)S which seals the

emissions vapors and fuel within the foe! tank 202. The cap 208 mates with a cap mating structure 210 which is also used to support a fuel filter or screen 209, fuel exits the tank 202 frorrs an exit location 214 such as a welded pipe fitting or Threaded sealed fitting. A threaded sealed fitting 214 is depicted in Figure 2 which also includes a brass fitting 216 which connects the exit 214 to a fuel shntoff valve 212, A ^Q uid passage line 218 connects the fuel sbutoff valve 212 to carburetor 220, During engine (not shown) operation, fuel is drawn from lank 202 through the fuel shutoff valve 212 and line 2IS to carburetor 220.

[00 IS ] When the engine is not in operation, external temperatures on the fuel tank

202 ean cause an Increase of the fuel 204 temperature within the tank 202 causing an increase in vapor pressure within Che tank 202, Historically, this increased vapor pressure was simply released through vent holes in the cap. However, new emissions regulations do not allow untreated vapor pressure to be released into the .atmosphere. Therefore, the vapor emissions system of the present invention directs the vapor pressure in the fuel tank 202 through a cbarcoal treatment section or canister 225, In the present invention, the vapor pressure is directed to a charcoal treatment canister or chamber 225 through a fuel tank valve assembly 230, The canister 225 typically uses activated carbon to treat the fuel vapor by removing the hydrocarbons. Once the engine is started the hydrocarbons from within the canister 225 are pulled into the carburetor 220 and burned.

10019] The fuel tarsk emissions valve assembly 230 is located inside ihe tank and includes a top portion 232 and an emissions line 233, The emissions vapor exits

lhe tank 202 from an exil focaiion 236 such as s -welded pips fitting or threaded

sealed tilting. A threaded sealed iϊmng 234 JS depicted m Figure 2 which aiso includes a brass fining 236 which connects the exit 234 to an emissions line 238 through connection 237, The emissions vapors are drawn into the top portion 232 of lhe valve assembly 230 and are then passed through lines 233 and 238 iuto canister 225 where the vapors are treated.

[Uiuyj The top portion 232 of the emissions valve assembly 230 .may be seenreά to ihe .inside top or side surface of tank 202. Additionally, or as an alternative, the emissions line 233 may be secured to a bracket 235, such as through welding or placement in a axonursei. where the bracket is secured to the inside of the tavsk 202, Securing the top 232 of the valve assembly 230 or securing ihe emissions line 233 prevents ihe emissions valve assembly 23(1 from significant movement thereby preventing or minimizing ihe emissions valve assembly 230 from becoming damaged, ShO further, line or tubs 233 may be a metal piping or some form of tubing which may be sealed or secured to ihe bottom of tank 202 through use of welding, a grommet or some other fitting,

[0021 ] Wtiers the engine is not running, pressure in the tank 202 will be released ss the emissions vapor flows from lhe top portion 232 of the valve assembly 230 down the emissions line 233, exits ihe tank 202 si the emissions exit 234 and flows into the canister 225 though line 238. Once in the chamber 225, ibe evaporate emissions vapor is treated. Upon starting the uiiliiy engine, suction is created drawmg outside air through vent 222 and pulling the evaporative emissions within the charcoal canister 225 through line 224 into carburetor 220

where the evaporaiive emissions and hydrocarbons can be burned. During

operation of the engine, emissiom vapor can also be draws-) bio the emission valve assembly 230, through treatment canister 225, arid into carburetor 220 where the emissions will be burned, Once the engine is shut off the suction pulling air through the charcoal canister 225 is removed and the canister 225 is ses to receive ana treat the evaporative emissions withb tank 2.02 until the engine is started again and the evaporative emissions cars be drawn into and burned by carburetor 220,,

As fuel 204 is added to iank 202 ihe fuel 204 wih reach or obtain & max fuel level 20δ. Exceeding the max fuel level 206 wom'd cause fuel 204 to overflow from IaBk 202, The present invention incorporates a design to prevent fuel 204 from entering the vapor emissions valve assembly 230 by sizing the valve assembly 230 so φ.m. the top portiors 232 of the vsive assembly 230 ss above the max fuel, level 206. SpeeiSe&lly, the v&lve assembly 230 is sized so th&i a valve opening for receiving emissions vapor is located above the ?riax fuaϊ levei 206 but below the top interior surface 20? of the tsnfc 202. The valve opening is located within the top portjon 232 of the v&h/e assembly 230. By having the valve opening above the max fuel level 206 the opening is positioned in area 205 where vapor pressure resides bat above the max fuel level 206 so thai fuel does not. easily How into the emissions vapor valve assembly 230 or line 233. Proper sizing of the valve assembly 230 may require sizing of both the valve assembly 230 and lnei iank 202.

;0 ^Q 23] As shown in Psgure 2, the tank 202 provides at least one high section or

vapor area 2OS which allows the fop portion 232 of valve assembly 230 to reside between the max fuel level 206 and the top interior surface 207 of the fuel tank 202, The distance between the top interior surface 207 ami the max fuel level 2OtS has some height "Ir ^; as shown in Figure 2. Understandably, for shipping, storage, and material costs there is a benefit to minimizing the height "h" while still, allowing enough space to properly place the valve opening wkhin the ιoρ portion 232 of valve assembly 230 wύhin area 205, IB a preferred embodiment, the height ¹ Ir" is about 1C) millimeters bat could be- as small as 1-2 millimeters and as large as the industrial design of the tank will aMow. However, u is unlikely that most tanks 202 would have an area 205 height "h" above several hundred mi Illtseters,

[0024] Figure 3 provides a more detailed view of the top portion 332 of the emissions valve assembly 330 for an exernolarv embodiment The too portion 232 of valve assembly 330 may be corrected to, in contact with or in close proximity to a top interior surface 30? of the fuel tank 202. The emissions valvε assembly 330 may be a roll over or snorkel type valve which JS comprised of a ball 340 or other float like device which is responsive >,o the fuel level 306. fuel is ai lowed to enter the valve chamber 346 through the chamber holes 342. As the fluid level πses, such as might happen when the unit is being moved or listed, the fuel level is chamber 346 will rise causing the float ball 340 to rise until it contacts tapered surface 348. A seal is created wbers the float bah 340 contacts the tapered surface 348 preventing the fuel from entering line 333.

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[0025] under normal conditions, the float ball 340 rest on the top of the fluid

surface level 306 within chamber 346 at some distance from the tapered surface 348. The evaporative emissions are able Io enter the chamber 346 from the top chamber holes 342 and flow through line 333 to the charcoal canister. The top portion 332 of the valve assembly 330 should be sized such Chat height ¹ If provides enough space to allow the evaporative emissions to escape when the float ball 340 is resting on the surface of the max fuel level 306.

[0026] As seen m Figures 2 arid 3, another aspect of the top portion 332 of lhc valve assembly 330 may be tht width "w" of the top portion 332. In one exemplary embodiment, the laisk 202 will have already been constructed with an opening located on ihe bottom of tank 202 for receiving the valve assembly 230, The opening is sized to øronerlv receive an aoproøriatelv srzed srommet or threaded Siting 234 to properly fasten and seal the valve assembly 230 to the tank 202. After the tarsk 202 is assembled, ihe entire valve assembly 330 wouid be inserted into the opening. Therefore, the width ^w" of the vaive assεmbiy 330 must be smaller then the width or diameter of the eutom or opening on toe bottom of fuel teπk 202, Oτ5e advantage of a valve assembly 330 properly sized for iπsertsoα into ao openiαg would be ease of removal of the valve assembly 230 for service or replacement The valve assembly 330 or the top portion 332 could include bends or sections enabling the total width ^! V of ihe valve assembly 230 to be vvider than the opening but no one poim coc-ld be larger than the opening. Farther, the opem ^' ng need not be on the bottom or undersrde of tank 202 and could be located in various other locations ors tank 202.

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[0027] Additionally, all or a portion o! valve assembly 230 could be placed in the

tank 202 prior to complex assembly of the tank 202. k one exemplary ernbodirnejii, the top portion 232 of the valve assembly 230 is fastened to the top surface 20? of ώe fuel tank 202. The line 233 might also be fastened to a bracket 235 tα support the valve assembly 330. Finally the two halves of the tank 202 would be mated and sealed together to from the tank 202 with all or a portion of the valve assembly 230 aiready in 202. The valve assembly or vapor ex U 234 could be a welded fitting, grommet or threaded Oiling to properly seal the vapor exit 234 from tank 202. In addition to metal, the tank 202 could also be constructed using a conventional blow molded plastic technique, or oiher known techniques, enabhng proper sizing and fitting of the tank 2(12 for interaction with the valve assembly 230,

|002S] Tank 202 would likely have a generally flat bottom, a generally flat top with a recessed opening 210 for cap 208, The opemng 210 for cap 20S would be lower than the highest point on the top surface of tank 202, The integral design of the fuel vapor valve assembly 230 located within the tank 202 allows for the top surface of the tank to be clean and free from valves and Hnes. Hie tank 202 would also have tour sidewaHs any or all of which may be mchned or configured with a unique shape as required for a particular application.

|002 ^§ ] hi addition to the snorkel or ball float valve depicted in Figure 3, the evaporative emissions system of ihe present invention could use alternative valve assembly designs. As seeu in Figures 4A and 4E, a Simple angled and open tube 433 could be used where ihe oocriins 43! resides above the max fuel level 406.

Figure 4B is a side elevation view of the line or tube 433 depicted in figure 4A..

Figure 5 provides an additional evaporative emissions system with an inverse 'T' or 180 degree bend at tbe lop of lube 533 such that the operήng 531 is below the maximum height of tube 533- The designs depicted in Figures 4A _> 411 and 5 do not create a seal preventing fuel from entering the line 433, 533 when the unit with the fuel lank 202 is tilted, slanted or moved. However, experimentation has shown that even with openings 431, 531 of a small diameter that very little fuel is allowed to pass through tubes 433, 533 even with vigorous sloshing, Stiil further, the evaporative emissions system 200 and the charcoal filter canister 225 can handle some fuel entering the earήster 225 as it will eventually evaporate, be treated, and burned by the carburetor 220.

[0030] Still further, the evaporative emissions system of the present invention could use a valve assembly which, comprises a much larger float device not within a defined valve assembly ohamber. The large float would be connected or attached to the valve assembly and could have a sealing element connected or incorporated into the float design to provide a sea! against tbe opening in the valve assembly leading to tbe vapor passage path or line,

[00311 The present invention provides an internal evaporative emissions valve assembly which is responsive to the fuel level with the fuel lank. Further, the top porn on of the fuel valve assembly, and specifically the opening in the valve assembly for receiving the fuel vapor, is positioned such that the valve assembly opening is above tbe max fuel level of the tank but below the interior top surface of the fuel ta&k.

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Although & preferred embodiment and exemplary embodiments of the

presem Invention has beers described m detail, έhe present invention is no? limited io the embodiments described herein and can be modified in a variety of ways without departing from the spirit and scope of the present inversion.