T E C H NICAL FIE LD

[001 ] The present invention relates to a mixing device for mixing and dispensing fuel and oil in different ratios and is particularly, but not exclusively, well suited for use with two stroke engines.

BAC KG R OU ND

[002] Any references to methods, apparatus or documents of the prior art are not to be taken as constituting any evidence or admission that they formed, or form part of the common general knowledge.

[003] Two-stroke engines are generally lighter, simpler, and less expensive than four- stroke or diesel engines. T herefore, many devices such as small outboard boat motors, jet skis, off-road motorcycles, and lawn and garden equipment including chain saws, leaf blowers, and weed trimmers typically employ a two-stroke engine.

[004] One of the shortcomings of a two-stroke engine is that unlike four stroke engines, two stroke engines do not include a separate oil chamber. To lubricate a two- stroke engine, oil must be mixed into the fuel that is introduced into the engine. The oil lubricates the crankcase bearings, pistons, rings etc. It is vital this procedure is carried out to prevent the engine from seizing. It is also important to note the required oil/fuel mixture. S ome engines require fuel/oil mixture of 50:1. Other two-stroke engines might require a fuel/oil ratio of 100:1. It is important to ensure that the correct amount of oil is poured into the fuel tank.

[005] In most cases, fuel and oil are maintained in separate containers, and then manually metered into and mixed in a third container. T his task not only requires multiple containers, but it can also be messy and difficult. S uch difficulty in mixing the fuel and oil for a two-stroke engine is exacerbated by the fact that many people own more than one device that employs a two-stroke engine. S ince each two-stroke engine generally requires its own particular ratio of fuel to oil, owners of more than one device using a two-stroke engine must repeat the aforementioned mixing process for each device.

[006] In view of the above, there is a need to provide an improved fuel and oil mixing device that allows a user to accurately and quickly mix the proper amounts of fuel and oil for multiple devices with varying fuel/oil ratios.

S U MMARY OF INVE NTIO N

[007] In an aspect, the invention provides a fuel and oil mixing device adapted to be secured to and used with a fuel container storing a quantity of a fuel and having an opening for dispensing the fuel, the device comprising:

an oil reservoir for holding a quantity of oil; the reservoir being fluidly coupled with a mixer including: a fluid input section extending between a first end and a second end wherein the first end comprises a receiving portion that is structured to be fluidly coupled with the opening of the container to receive fuel from the container;

a throat section disposed atthe second end of the first fluid input section, the throat being fluidly coupled to the oil reservoir for delivering oil into the throat section;

an output section having a first end connected with the throat and a second end wherein the second end comprises an outlet for dispensing a fuel-oil mixture .

an oil metering member for controlling flow of the oil from said oil reservoir into the throat of the mixer.

[008] In an embodiment, the fuel and oil mixing device further comprises an adjustment member connected to the oil metering member such that movement of the adjustment knob by a user allows for a selection of a desired fuel-oil ratio, such that the mixture with the desired fuel-oil ratio can be dispensed from the outlet of the mixer.

[009] In an embodiment the fluid input section comprises a decreasing cross sectional area from the first end to the second end of the first fluid input section.

[010] In an embodiment the output section comprises an increasing cross sectional area from the first end to the second end of the output section. [01 1 ] In an embodiment, the oil metering member housed in a cavity defined by said mixer body for controlling flow of the oil from said oil reservoir into the throat of the mixer.

[012] In an embodiment the oil metering member is housed in a cavity defined by said mixer body for controlling flow of the oil from said oil reservoir into the throat of the mixer.

[013] In an embodiment, the oil metering member comprises a spherical body with a cylindrical bore extending therethrough for allowing flow of oil from the reservoir into the throat.

[014] In an embodiment, orientation of the bore within the cavity can be varied to control the flow rate of oil flowing into the throat of the mixer to thereby allow the mixture with the desired fuel-oil ratio to be dispensed from the outlet of the mixer.

[01 5] In an embodiment movement of the adjustment knob effects movement of the spherical body thereby allowing for a selection of a desired fuel-oil ratio.

[01 6] In an embodiment, the outlet comprises a convergent configuration with a downwardly directed fuel dispensing portion that is angled relative to a connecting portion connected to the second end of the outlet section. [017] In an embodiment the oil reservoir comprises a cylindrical oil receiving container with a downwardly extending an outlet being fluidly coupled with the throat section of the mixer.

[018] In an embodiment, the oil metering member is positioned in the fluid flow path of the oil flowing from the reservoir to the throat section.

[019] In an embodiment, the first end of the fluid input section is adapted to be coupled with a nozzle of the fuel container, said nozzle being located at the opening of the container.

[020] In at least some embodiments, the first end of the fluid input section is integrally formed with the nozzle.

[021 ] In another aspect, the invention provides a fuel and oil mixing device adapted to be secured to and used with a fuel container storing a quantity of a fuel and having an opening for dispensing the fuel, the device comprising:

an oil reservoir for holding a quantity of oil; the reservoir being fluidly coupled with a venturi mixer, the mixer including:

a fluid input section extending between a first end and a second end wherein the first end comprises a receiving portion that is structured to be fluidly coupled with the opening of the container to receive fuel from the container wherein the fluid input section comprises a decreasing cross sectional area from the first end to the second end of the first fluid input section; a throat section disposed at the second end of the first fluid input section, the throat being fluidly coupled to the oil reservoir for delivering oil into the throat section; an output section having a first end connected with the throat and a second end wherein the second end is coupled to an outletfor dispensing a fuel-oil mixture wherein the output section comprises an increasing cross sectional area from the first end to the second end of the output section; and

an oil metering member for controlling flow of the oil from said oil reservoir into the throat of the mixer.

B RIE F DE S C RIPTIO N OF T H E DRAWINGS

[022] P referred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding S ummary of the Invention in any way. The Detailed Description will make reference to a number of drawings as follows:

F igure 1 is a perspective view of a fuel and oil mixing device 100 in accordance with an embodiment of the present invention.

F igure 2 is an in-use perspective view of the fuel and oil mixing device 100.

F igure 3 is an exploded view of the fuel and oil mixing device 100.

F igure 4 is a top perspective view of the venturi mixer 120 that forms a part of the fuel and oil mixing device 100.

F igure 5 is a sectional view of the venturi mixer 120.

F igure 6 is a perspective view of the oil metering member 125 that forms a part of the fuel and oil mixing device 100. F igure 7 a top view of the oil metering member 125. Figure 8 is a side view of the oil metering member 125. Figure 9 is a frontal view of the oil metering member 125.

Figure 10 is a perspective view of an adjustment member 150 thatforms a part of the fuel and oil mixing device 100.

Figure 11 is a frontal view of the adjustment member 150.

F igure 12 is a top view of the adjustment member 150.

Figure 13 is a sectional side view of the adjustment member 150.

Figure 14 is a perspective view of the lid 112 for the oil reservoirllO thatforms a part of the fuel and oil mixing device 100.

Figure 15 is an isolated view of the oil reservoir 110.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[023] Figures 1 to 3 illustrate a fuel and oil mixing device 100 in accordance with a non-limiting embodiment of the presently described invention. The mixing device 100 is adapted to be secured to and used with a fuel container (C) storing a quantity of a fuel. As shown in Figure 2, the mixing device 100 is particularly useful because it can be directly coupled to an opening (O) of the container that otherwise dispenses fuel (without any oil) out of the container (C). The device 100 comprises an oil reservoir 110 for holding a quantity of oil. The reservoir 110 (detailed views shown in Figures 14 and 15) is cylindrical in shape and includes an upper portion comprising a screw cap 112 that engages with helical threads to allow the cap 112 to be opened for filling the reservoir with oil. The reservoir 1 10 includes a narrower lower portion 125 in fig 1 that is fluidly coupled to a venturi mixer 120 for delivering the oil from the reservoir 1 10 into the mixer 120.

[024] The venturi mixer 120 (detailed views shown in F igures 4 and 5) includes: a fluid input section 130 that includes a receiving portion 136 that is configured to be coupled to the opening (O) of the container (C). The fluid input section 130 extends between a first end 132 and a second end 134 which is narrower relative to the first end 132. The fluid input section 130 comprises a decreasing cross sectional area from the first end 132 to the second end 134 of the fluid input section 130. The venturi mixer 120 also includes a throat section 190 that is disposed at the second end 134 of the fluid input section 130. The throat section 190 includes an inlet 124 that is fluidly coupled with the oil reservoir 1 10 for delivering oil from the reservoir 1 10 into the throat section 190 to allow the fuel (received into the fluid input section 130) to mix with the oil (from the reservoir 1 10) in the throat section 190. In the preferred embodiment, the fluid input section 130 includes an attachment arrangement 136 that allows the fluid input section 130 to form a substantially leak-proof seal with a nozzle (N) that is typically provided on the opening of fuel containers such as container (C). In the preferred embodiment, the attachment arrangement 136 comprises a threaded arrangement to allow the fluid input section 130 to form a seal with the nozzle to allow fuel from the container (C) to flow into the fluid input section 130. The venturi mixer 120 also includes an output section 140 having a first end 144 that is connected with the throat section 190 and a second end 142 that is connected with an outlet member 160 for dispensing the fuel-oil mixture formed in the throat section 190. The output section 140 comprises an increasing cross sectional area from the first end 144 to the second end 142 of the output section. The outlet member 1 60 includes a fuel dispensing portion 164 that is angled relative to a connecting portion 162 connected to the second end 142 of the outlet section 140. The fuel dispensing portion 1 64 comprises a convergent configuration to allow a fuel hose to be attached thereto.

[025] The geometry of the variable diameter in the fluid input section 130 and the fluid output section 140 with the constricted throat section 190 (in between the fluid input and output sections 130 and 140) gives rise to the Venturi effect S pecifically, as the fuel (from container C) flows into the fluid input section 130 from the first end 132 to the relatively narrower second end 134 a vacuum is created in the throat section 190 that is a result of a reduction in fluid pressure and in increase in fluid velocity of the fuel flowing through the constricted throat section 190. The creation of the vacuum in the throat section 190 draws the oil from the reservoir 1 10 resulting in the formation of a fuel/oil mixture in the throat section 190. The provision of an oil metering member 125 helps in controlling the quantity of oil entering the throat section 190 of the mixing chamber 120. During use, the lid 1 12 is slightly loosened to allow air to flow into the reservoir 1 10. Without being bound by theory, the inventors believe that a mixture of air and oil flows into the throat section 190 when the vacuum is created in the throat section 190 (as a result of fuel flowing through the convergent fluid input section 130). The provision of the oil metering member 125 limits the quantity of oil and air that can flow into the throat section 190 at any given time. The pressure of the air and oil pushing through the oil metering member 125 mixes the fuel (from the fluid input section 130) with the oil and air and forces out the fuel and oil mixture in a desired mixture ratio. The oil metering member 160 controls the quantity of oil that can enter into the throat section 190 thereby allowing a user to easily and efficiently dispense a fuel and oil mixture in a desired ratio. [026] The configuration of the oil metering oil metering member 125 may be varied in accordance with the specific mixing requirements of the user. In the preferred embodiment the oil metering member 125 is substantially spherical with a spherical body 1254 and a hollow cylindrical bore 1251 that allows passage of oil from the oil reservoir 1 10 into the throat section 190. An adjustment member 150 is provided for allowing a user to control the movement of the oil metering member 125. The movement of the oil metering member 125 effects changes in the orientation of the cylindrical bore 1251 thereby determining the quantity of oil that can flow out of the reservoir 1 10 into the throat section 190 of the mixing chamber 120. By way of example, in one operable position, the user may position the adjustment member 150 to align the cylindrical bore 1251 to be coaxial with lower portion 125 of reservoir 1 10 and also with inlet 124 of the venturi mixer 120 of the oil metering member 125 in a substantially upright position to allow the entire opening of the bore 1251 to be able to receive oil from the reservoir 1 10. T he user may adjustthe orientation of the cylindrical bore by twisting the adjustment member 150 to alter the orientation of the cylindrical bore 1251 such thatthe opening of the cylindrical bore 1251 becomes partially covered by the walls of the inner cavity 124 (that houses the oil metering member 125). As a result only a portion of the opening of the cylindrical bore 1251 is available for the oil to flow into. Therefore, twisting of the adjustment member 150 allows metering of the oil flowing into the throat section 190 of the venturi mixer 120.

[027] R eferring to F igures 10 to 13, the adjustment member 150 comprises an engagement formation 154 that is adapted to be receivably engaged with a corresponding member 1251 provided on the oil metering member 125. In the preferred embodiment, the corresponding member 1251 projects outwards from the spherical oil metering member and is adapted to mate with the engagement formation 154 such that twisting of the adjustment member 1 50 effects movement of the spherical oil metering member 125. Advantageously, the adjustment member 150 is provided with a dial with markings 1 52 to indicate various fuel/oil ratios with each marking corresponding to a specific fuel/oil ratio. C onsequently, the presently described mixing device 100 allows the user to read the dial and twist the adjustment member 1 50 to a specific marking on the dial in order to thereby rotate oil metering member 160 and achieve the corresponding fuel/oil mixture.

[028] In an alternative embodiment, the first end 132 of the fluid input section may be integrally formed with the removable nozzle (such as N-shown in Figure 2) that is typically provided at the opening of a fuel container.

[029] The mixing device 100 is adapted to be secured to and used with a fuel container (C) storing a quantity of a fuel. As shown in F igure 2, the mixing device 100 is particularly useful because it can be directly coupled to an opening (O) of the container that otherwise dispenses fuel (without any oil) out of the container (C). The device 100 comprises an oil reservoir 1 10 for holding a quantity of oil. The reservoir 1 10 (detailed views shown in F igures 14 and 15) is cylindrical in shape and includes an upper portion comprising a screw cap 1 12 that engages with helical threads to allow the cap 1 12 to be opened for filling the reservoir with oil. The reservoir 1 10 includes a narrower lower portion 125 in fig 1 that is fluidly coupled to a venturi mixer 120 for delivering the oil from the reservoir 1 10 into the mixer 120.

[030] In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. The term comprises _, and its variations, such as comprising _, and comprised of_ is used throughout in an inclusive sense and not to the exclusion of any additional features.

[031 ] It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect.

[032] The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted by those skilled in the art.