Patent Application
20200025153
This application claims the benefit of provisional application #201762536440, filed 24 Jul. 2017.
The following is a tabulation of some prior art that presently appears relevant
The invention relates to an attachment which is mounted on an engine carburetor and method of purging the inside of the carburetor before the machines are put to storage.
Engines produced to date for use in outdoor power equipment are not designed for gasoline with ethanol (such as E10, E15, E20 and E85); using higher ethanol fuel blends may lead to engine damage and/or performance issues.
During periods of extended storage, ethanol tends to draw in atmospheric moisture which can lead to a build-up of water in the carburetor bowl and fuel tank. Since the carburetor is vented and the moisture in the air is being taken up by the ethanol, new air brings more moisture through to the vent. Inside the carburetor bowl, because the density of water is greater than gasoline, the ethanol/water mixture separates from the gasoline and settles to the bottom of the bowl. Industry refers to this as “Phase Separation” and because the fuel pick-up inside the carburetor bowl is located on the bottom, the first thing sucked up through the jets is the ethanol/water mixture.
In addition, the ethanol and water mix in gasoline is a breeding ground for microbes like bacteria and fungi which just adds to the corrosion and debris inside the carburetor bowl. These deposits clog the carburetor jets and fuel and air passages inside the carburetor which is main reason why the engine won't start or will operate poorly.
Even if the engine is run dry at the end of the season, there will still be some fuel left in the carburetor. This turns to gum and varnish and dirt and restricts the passages inside the carburetor.
On a brand-new engine fouling with gum and varnish can also happen. This is because of the fuel that the factory puts into the carburetor when they are testing it. They then run it dry before the shipping. But, there is always still some fuel inside the carburetor. In all the cases, the carburetors have to be removed from the equipment engines and thoroughly cleaned. The only successful way in bringing the carburetor to a good condition again is to take it all a part and clean it in an ultrasonic cleaner.
Most engine manufacturers recommend using a fuel stabilizer or draining the fuel system before putting the machine into storage.
Most fuel stabilizers form a layer over the top of the gasoline and reduce the rate the fuel's volatile compounds evaporate. They also prevent the absorption of moisture by the fuel. Fuel stabilizer will not prevent but will only retard the separation into more than one phase of gasoline-ethanol solutions in the presence of small amounts of water. Since the stabilizers are effective in the case of a bulk of fuel like the fuel inside fuel tank or carburetor bowl, the stabilizers can't prevent molding inside the carburetor fine passages where film of fuel/ethanol is left after the engine stops running. US Department of Energy's Oak Ridge National Laboratory warns against the use of ethanol with zinc or aluminum carburetors. Additives designed to help prevent phase separation generally contain alcohol which can make the corrosion problem worse.
U.S. Pat. No. 7,104,528 on relates to an improved fuel processor for preparing fuel prior to introducing the fuel into a combustor utilized in connection with a gas internal combustion engine.
U.S. Pat. No. 7,090,205 relates to a premixed air-fuel mixture supply device.
U.S. Pat. No. 7,513,489 incorporating a fuel metering device and fuel processing device for producing a stabilized fog of fuel droplets U.S. Pat. No. 7,780,151 is a mixer assembly and a method for forming a fuel-air mixture.
U.S. Pat. No. 7,237,768 relates to a fuel injector is coupled to a fuel source. A vortex generator is coupled with the injector and a gas source.
U.S. Pat. No. 7,717,096 provides methods and apparatus for premixing fuel and oxidant for combustion.
U.S. Pat. No. 7,744,066 relates to a carburetor comprising an air inlet with a mechanically adjustable air valve and a mechanically adjustable atomizer.
U.S. Pat. No. 8,028,674 relates to a fuel nozzle, a pre-combustion fuel mixing device, and methods related to fuel processing.
U.S. Pat. No. 7,547,002 relates to systems and methods for injecting and mixing a liquid hydrocarbon fuel to provide a uniform, homogenous fuel vapor mixture.
U.S. Pat. No. 8,151,774 relates to an engine combustion air pre-cleaner includes a body shaped for effecting cyclonic air flow between an inlet and an outlet of the body.
The invention disclosed in this device relates to purging left over fuel in outdoor power equipment prior to storage. None of the found patents discussed the issue of purging a carburetor, instead they focused on fuel mixing and atomization of fuel for better efficiency.
A point of particular interest in the discussion of the device disclosed in this application is the general use today are quick disconnect attachments for compressed air and other car tires inflatables. These devices are popular because of their simplicity of connection and disconnection and their efficiency of use. However, the devices are not compatible with present day small engines carburetor exterior because of the lack of a quick connect receiver to connect the same to engines carburetors. It would be a significant improvement in the field if such quick disconnect attachments could be used to internally purge the carburetors from remaining fuel and ethanol.
A need exists for an attachment for small engines carburetors which efficiently purges the interior of the carburetor without taking them apart, is inexpensive, is easy to install, is easily attachable to, and easily disconnect-able from a compressed air source and/or a pressurized can.
The adapter does not create a carburetor operation problem because ultimately the carburetor retaining screw or drain plug gets replaced with the same type adapter end as it currently has.
A quick-connect hookup that includes a connector and an adapter designed for quick and easy assembly and disassembly from a common small engine carburetor bowl retaining screw, carburetor drain plug or carburetor fuel feed line. The adapter is formed with a standardized threaded section on one side and a customized threaded section on the other. The customized threaded section of the adapter is made to fit within an outlet of the small engine carburetor bowl retaining assembly, drain plug or carburetor fuel feed line in substantially permanent manner. The standard section of the adapter includes threads that are made to quickly attach to and detach from a tire chuck type connector (tire inflator nozzle head). On the inside, the adapter contains a one-way pneumatic valve (Schrader type valve) and an orifice in series with the one-way valve. The invention includes a method of connecting and purging remaining fuel inside the carburetor through a one-way valve (Schrader valve) and an orifice with the use of compressed air and a cleaning solution and the quick-connect hookup before the machines are put into storage.
1. It is an object of this invention to provide an adapter with one-way valve (purge valve) on inside formed with an external standardized threaded section on one side and a customized threaded section on the other.
2. It is an object of this invention to provide the one-way valve adapter (purge valve) with the external standardized threaded section to fit tire chuck type connector (tire inflator nozzle head).
3. It is an object of this invention to provide the adapter (purge valve) with the external customized threaded section to fit within an outlet of the small engine float type carburetor bowl in substantially permanent manner.
4. It is an object of this invention to provide the adapter (purge valve) with the external customized threaded section to fit within an outlet of the small engine float type carburetor bowl retaining assembly in substantially permanent manner.
5. It is an object of this invention to provide the adapter (purge valve) with the external customized threaded section to fit within an outlet of the small engine float type carburetor bowl drain in substantially permanent manner.
6. It is an object of this invention to provide the adapter (purge valve) with the external customized threaded section to fit within a three-way valve section in substantially permanent manner.
7. It is an object of this invention to provide the adapter (purge valve) with the external customized barb hose section to fit within a small engine carburetor fuel feed hose in substantially permanent manner.
8. It is an object of this invention to provide the purge valve's inside part (valve core) with one-way valve (Schrader type valve) on the inlet side of the purge valve.
9. It is an object of this invention to provide the purge valve's inside part with a flow limiting orifice on the outlet side of the purge valve.
10. It is an object of this invention to provide a disconnect (shut off) of the feed fuel line from fuel tank to carburetor through a permanently installed two-way valve, three-way valve or check valve.
11. It is an object of this invention to provide a one-way valve adapter (purge valve) permanently installed through a tee fitting within fuel feed hose from fuel tank to carburetor upstream of the two-way or check valve.
12. It is an object of this invention to install three-way valve into the fuel line from the fuel tank to the carburetor with a purge valve connected to one of the ports of the three-way valve.
13. It is an object of this invention to provide a method of carburetor purging from remaining gasoline and ethanol left inside the carburetor bowl, jets and passages after the fuel has been drained from carburetor or the carburetor has been run dry.
14. It is an object of this invention to provide a method of fuel shut-off valve and fuel lines purging from remaining gasoline and ethanol after the fuel has been drained from the fuel system (carburetor, fuel valve, fuel lines, fuel tank) or the system has been run dry.
15. Another object of this invention is to provide a method for purging the inside of the carburetor bowl, jets and passages without taking the carburetor apart.
16. Another object of this invention is to provide a method for purging the inside of the carburetor bowl, jets and passages without removing the carburetor from the engine.
17. It is still another object of this invention to provide the purging of the inside of the carburetor bowl, jets and passages with compressed air.
18. It is still another object of this invention to provide the purging of the inside of the carburetor bowl, jets and passages with a compressed purging agent from a spray can.
19. It is still another object of this invention to provide the purging pressurized can with a release valve, hose and tire inflator nozzle head.
20. It is further object of this invention to purge the bowl, jets and passages located on the inside of carburetor at the same time with multiple short blasts of compressed air or pressurized can solvent.
21. It is further object of this invention to leave the carburetor bowl fuel drain plug (if equipped) off during purging to get the bulk of fuel left on the bottom of the bowl out of the carburetor first.
22. It is further object of this invention to purge the remaining fuel inside the jets and small passages with the carburetor bowl fuel drain plug (if equipped) on to pressurize the internals of the carburetor with higher pressure.
23. It is further object of this invention to drain the fuel from the carburetor through the purge valve itself once the valve core is removed.
24. It is further object of this invention to purge the carburetor with valve core off.
25. It is also an object of this invention to use pressurized can filled with Halocarbon 152A (R-152a), Hydrofluorocarbon-134a (R-134a), propane, butane gas or any other gases or mixture of gases and liquids.
26. It is also an object of this invention to mix purge gas inside the pressurized can with an anti-corrosion additive.
27. It is also an object of this invention to provide a small amount of mineral oil or any other type of oil inside the pressurized gas can to leave a very small oil film inside the carburetor on all the surfaces of the jets, passages and bowl.
28. It is an object of this invention to purge the carburetor through the three-way valve with the three-way valve in position where the purge gas is directed to the carburetor only and not to the fuel tank.
29. It is an object of this invention to install two-way valve and a tee fitting into the fuel line from the fuel tank to the carburetor with a purge valve connected to one of the ports of the tee fitting.
30. It is an object of this invention to purge the carburetor through the two-way valve with the two-way valve in position where the purge gas is directed to the carburetor only and not to the fuel tank.
31. It is an object of this invention to install check valve and a tee fitting into the fuel line from the fuel tank to the carburetor with a purge valve connected to one of the ports of the tee fitting.
32. It is an object of this invention to manually activate diaphragm type carburetor primer bulb to establish initial pressurized gas flow through the carburetor.
A small engine float type carburetor exploded view is shown in
During engine operation the fuel from inside the bowl gets sucked through the main fuel jet 4, emulsion tube 3 and idle jet 19. All the fuel jets and the internal passages of the carburetor get wet with the fuel. Once the engine stops, some of the fuel from the jets and internal passages drains back to the bowl while some of it remains inside the jets and passages in a form of a tiny fuel film. The fuel remains inside the small openings of the jets and passages because of the fluid capillary effect. Over long sitting the ethanol from the fuel attracts water and corrosion builds up inside the small jets and passages. Over even longer period of sitting, the fuel from the bowl evaporates leaving corrosion and debris on the bottom of the bowl causing substantial problems when the engine is next time started. To prevent the formation of deposits inside the bowl, jets and passages the inside purging of the carburetor is suggested.
The present invention has overcome these problems by purging the carburetor bowl 11, all the jets and all the passages with a compressed air and/or pressurized cleaning solvent. The installation of the purge valve 43 on a preassembled carburetor is simple. The carburetor's bowl retaining screw 10 is replaced with the purge valve 43 assembly,
Exploded view and cross section of the pneumatic one-way (Schrader) valve and cross section of the adapter assembly is shown in
Over-pressurization of the inside of the carburetor and in specific the primer bulb if equipped (not shown) connected to the carburetor is prevented by limited purge air flow. For this purpose, inside the metal tube 40 and on the customized threaded section 45 an orifice 46 is provided. In respect to the gas flow sense through the purge valve assembly 43, the orifice 46 is located after the valve core 41.
In the center of the exterior metal tube end is the valve core 41. The core of the valve can be removed or tightened with a tool. The fuel from the carburetor and fuel tank can be drained through the purge valve once the valve core 41 is removed.
A valve cap 42 is used on a pneumatic one-way (Schrader) valve assembly 43 because if one is not fitted, dirt and water can enter the outside of the valve, potentially jamming it or contaminating the sealing surfaces and causing a leak.
The cross section of the divided purge valve assembly is shown in
Pressurized with air and/or cleaning solvent can 51 connected through the quick connect nozzle 50 and purge valve 43 to the carburetor is shown in
It is important to mention that the entire purge cycle is done on the carburetor 1 installed on the engine 100,
In order for a combustion engine to run properly at different speeds and loads, the carburetor design provides four specific operating systems:
a. Fuel delivery to bowl
b. Idle system
c. Transition system
d. Main system
Since the fuel gets in contact with all the four systems components, all the surfaces of the jets and passages of the four systems inside the carburetor have to be purged.
With the fuel drained out of the carburetor through the drain plug 21 and the quick connect nozzle 50 attached to the purge valve 43 the carburetor is ready to be purged,
Compressed air enters the carburetor bowl cavity 70 through the purge valve and the two small openings 71 located beneath the main fuel jet,
In case the fuel valve 16 is left open the air from inside the bowl escapes through the needle valve sit 76, fuel filter 18 and fuel delivery port 7 into the fuel tank (not shown). For this purpose, entire amount of fuel has to be drained from the fuel tank before the purging. In order to easier purge the remaining fuel from the bottom of the bowl, the drain plug 21 can be removed and the mixture of remaining fuel and purge air or gas can escape through the drain plug opening 95,
As the purge air enters through the purge valve 43, it pressurizes the bowl and all the internal passages of the carburetor. As shown in
It is necessary to mention that all four carburetor systems: bowl, idle, transition and main system get purged at the same time with multiple short blasts of compressed air or spray can solvent.
a. Carburetor bowl purging is represented with circle full arrow lines
b. Idle and transition fuel system purging are represented with straight dashed arrow lines
c. Main fuel system purging is represented with straight full arrows lines.
In case of the motorcycle float type carburetor, the drain screw/plug 10 gets replaced with the purge valve assembly,
Motorcycle type purge valve assembly is shown in
The motorcycle type carburetor is a very similar design as the float type carburetors for the power equipment,
In case the fuel supply valve to the carburetor (not shown) is left open the air from inside the bowl escapes through the needle valve sit 76 and fuel delivery port 7 into the fuel tank (not shown). For this purpose, entire amount of fuel has to be drained from the fuel tank before the purging.
Small hand-held power equipment uses diaphragm type carburetors (carburetor that can operate in any position even upside down). Diaphragm type carburetors can be found and on other types of engines like engines for watercrafts or airplanes.
To separate the fuel tank 110 from the carburetor 1 so the inside of the carburetor can be pressurized, a three-way valve 57 can be installed on the fuel feed line 55,
The purge valve 43 used on the diaphragm carburetors is of the same kind as the purge valve used on the float type carburetors for the power equipment machinery.
Alternatively, the three-way valve can be replaced with a two-way valve 58 and a hose fitting tee 59. With this arrangement, the purge valve 43 is connected to one of the tee fitting 59 end,
While keeping the tee fitting the same, the two-way valve 58 can be replaced with check valve 56. During engine operation the check valve allows fuel to flow straight from the tank to the carburetor. During purging, the check valve will allow the gas to flow only to the carburetor
Finally, the carburetor can be pressurized without any type of valves installed but for this system the fuel hoses from the carburetor ports 1a and 1b have to be disconnected. Pressurized can 51 hose 50b attaches directly to the carburetor inlet port 1a,
With either of the arrangements, once activated, the pressurized gas from the can flows through the purge valve into the carburetor through the fuel inlet port 1a and into the diaphragm type pump 114.
If equipped with a primer bulb 126, on its way out of the carburetor the gas flows through the primer bulb chamber inlet valve 123 and outlet valve 124. The entire amount of liquid fuel and ethanol get purged out through the carburetor outlet port (1b) into the fuel tank.
Manual activation of the primer bulb 126 can help establish initial pressurized gas flow through the carburetor,
The method of purging the carburetor described is so great that thoroughly cleans the entire interior of the carburetor.
The unique construction of the purge valve provides flush non-protruding abutment within the carburetor casing or fuel feed line, not interfering with the carburetor operation. Additional advantages include that the purge valve is easily attachable and removable from the carburetor but most importantly finally permits commercial disconnect compressed air attachments to be used in purging carburetors.
While particular embodiments of the invention have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. The final result is that the efficiency of purging of the inside of carburetors is so great it leaves carburetors like in new condition.
