FORM 2
THE PATENTS ACT, 1970 (39 of 1970)
THE PATENS RULES, 2003
PROVISIONAL SPECIFICATION
[See section 10, Rule 13]
DELIVERY-TO-DELIVERY VARIABLE
MIXING PUMP;
LARSEN & TOUBRO LIMITEb, A COMPANY INCORPORATED UNDEF} THE COMPANIES ACT, 1956, WHOSE ADDRESS IS L&T HOUSE, BAL|_ARD ESTATE, MUMBAI - 400 001, MAHARASHTRA, INDIA..


THE FOLLOWING SPECIFICATION
DESCRIBES THE NATURE OF THIS INVENTION :


FIELD OF THE INVENTION
This invention relates to fluid dispensers and more particularly to fuel dispensers and fuel pumps.
BACKGROUND OF THE INVENTION
A fluid dispensing equipment precisely dispenses fuel in an accurate repetitive manner controlled by a microprocessor and/or a control machine. Fluid dispensing equipments include manual and power driven dispensers that dispense, mix and dispense, or mix, meter and dispense fluid media.
As per the use, a fuel dispenser may be configured to deliver the fuel in different modes such as dispense drily; mix and dispense; or meter, mix and dispense applications. In the 'dispense only' mode, the unit is generally designed to dispense only. Such designs do not incorporate any mixing or monitoring operations. Mix and dispense units mix two or more items at a determined ratio and then dispense the product. Meter, mix and dispense units meter, mix and dispense items with a determined mix ratio and shot size. Important specifications for fluid dispensing equipment include dispense rate, media viscosity, container size, shot size or volumetric quantity.
The fuel dispenser may require the mechanism of mixing fuel with other liquid such as oil or lube for a two stroke engines. It is known in the art that machines employing two-cycle engines or two stroke engines require mixed fuel wherein a oroper ratio of oil to gasoline in the fuel mixture according to manufacturer specifications is needed to be maintained. If the ratio is not properly maintained, the engine may burn up or otherwise become damaged.

Yet, absent laborious monitoring of the fuel mixture ratio, remembering at all times to add oil to the gasoline, this can be easily overlooked.
Some prior patent applications disclose the solution of above-mentioned problems as described below.
US patent application US 6,250,154 discloses an Oil and gas metering and measuring device wherein a fluid metering and measuring device is provided and which is particularly adapted to regulate ratios of oil" and gasoline in a mixture of oil and gasoline used, for example, in a two-stroke engine. The device has a filling chamber with a fluid inlet and a fluid outlet. One-way check valves are disposed in both the fluid inlet and the fluid outlet to prevent backflow. A plunger stem comprising a piston disposed within the chamber. When the stem and attached piston are pulled upwardly, a vacuum is created in the chamber to cause a fluid, e.g. oil to flow into chamber and when depressed causes outflow. Gradations or indicia indicate the amount of oil drawn into the chamber to ensure proper fluid ratios. The metering device may be incorporated into any suitable container including a two-compartment container wherein the compartments are in fluid communication.
However, this oil & Gas metering & measuring device is a manual device, where the oil gas (fuel) proportions made manually without any quantity /volume display. Hence the delivery might not be very accurate as per the customer's requirement.
Another patent application US 6,253,779 "Blending system and method using an auxiliary measuring device" discloses a system for blending two-blend components to form a blended final product including a first supply line for supplying a first blend component at a first flow rate and a second supply line

for supplying a second blend component at a second flow rate. The first supply line and the second supply line intersect to form a blended product line. The system further includes a blended product measuring device positioned in the blended product line for measuring the flow rate of the blended product and an auxiliary measuring device positioned in the first supply line for measuring the flow rate of the first blend component. The auxiliary measuring device may have a degree of accuracy less than that of tfre-btefided-product meter. Alternatively, the auxiliary measuring device may have the same level of accuracy as that of the blended product meter. A calculation device determines the flow rate of the second blend component by measuring the difference between the flow rates measured by the blended —product meter and the auxiliary measuring device. A method for determining the inputs to a blending system for blending a first blend component and a second blend component to form a blended mixture. The method includes measuring the flow rate of the blended mixture directly using a blended mixture flow meter and measuring the flow rate of the first blend component directly using an auxiliary measuring device having substantially less accuracy than that of the blended product flow meter. The flow rate of the second blend component is determined by measuring the difference between the blended mixture flow rate and the first blend component flow rate.
The above patent describes a system that is intended Ito measure a blend of two components. The blend is mixed prior to metering and hence lacks the flexibility in metering and delivering independent components as per customer's requirement. Since the customer is unable to mix the fuel as per his requirement.

Another patent application US 6,269,981 discloses Oil dispensing apparatus wherein an oil dispenser for use on two-cycle engines such as outboard motors or other two-cycle engines, which require a mixture of oil and gasoline. The invention provides for measured volume displacement of oil via a plunger type pump attached at one end to a first fluid containment vessel via a threaded connection. A flexible tube of appropriate internal dimension and length facilitates transport of oil from said first containment vessel, through said pump to, and through a said flexible tube and valve located on the opposite terminus of said invention and into a second fluid containment vessel.
Another product, FUEL DISPENSER DPX-A, MIX MODEL, MAKE NUVO PIGNONE includes the feature of mixing oil and fuel at the nozzle point'. However this model does not give flexibility of selecting dispensing of either fuel or oil only. This model also lacks the flexibility of mixing. Moreover the mechanical arrangement of mixing the fuel and the oil in this model is not very accurate and is error prone. Further, the oil incremental display is also not available in the existing product.
The present invention, as will be subsequently detailed, overcomes these problems by providing a device that readily assures that proper ratios are maintained.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig 1 shows the diagrammatic representation of the variable mixing pump.
Fig 2 shows the diagrammatic representation of the manifold as per the present invention.
Fig. 3 shows the hydraulic circuit details of the variable mixing pump.

DESCRIPTION OF THE INVENTION
The present invention can be embodied in the mounting types including container mounted, hand held, machine mounted, or the like. The present invention provides a fuel dispenser,, which can pump, meter, mix and dispense the precise amount of lube oil with petrol in a unique way by using the common nozzle.
The lube oil mixing in the fuel is required for the vehicles having two stroke engines; this is to maintain the required amount of oil percentage in fuel to avoid the fugitive emissions from the vehicle.
Figure 1 shows the diagrammatic representation of the variable mixing pump. The mixing pump comprises two sets of display cards (3) and a hose pipe(2) which is connected to the pump with a connector (1). The other end of the hosepipe comprises a one-delivery nozzle (4) for two streams (petrol & oil).
The flow path for Petrol & Oil is as shown in the hydraulic circuit details in figure 2. As shown in figure 2 the dispenser comprises an internal oil reservoir (18). from which a gear pump (17) pumps oil and send it to the four piston positive displacement oil meter (13), which will measure the oil and correspondingly send the electrical signal to the controller CPU (11) to register the amount of oil being, delivered. A two-stage flow cut-off valve is fitted at the meter (13) outlet, which will cut off the flow of oil after receiving a signal from the controller (11). The metered oil as per decided proportion will be carrier to the dispensing nozzle (19) through a transparent tube, which will run parallel to the fuel hose. The two streams of fuel and oil will get mixed at the nozzle (19) inlet in a manifold (16).

The detailed diagram of the manifold is shown in figure 3. The manifold is specially designed to take care of the two pressurized inlet streams, mix them homogeneously and keep them flowing in the desired direction only. Manifold (16) is an important component in variable mixing pump. This is the point where the fuel and oil streams get mixed to form the homogeneous mixer to be delivered through the nozzle (19).
Referring now to figure 2, fuel and oil comes through separate hoses to.the entry poirits of manifold shown as 'FUEL IN' (10) and 'OIL W (20). the constant flow in only one direction is assured by two Non-return Valves shown as NRV for Fuel (30) and NRV for Oil (40) respectively. The common outlet (50) of this manifold is given to the nozzle for final dispensing.
The present dispenser can mix oil and fuel in terms of selected volume, percentage and value. The various desired combinations can be selected from the preset keypad.
The proposed variable mixing pump will have two independent systems, one for Oil and another for Petrol. The two fluid streams will merge/mix at nozzle inlet. There will be two display cards on each side. The additional LCD's will be used for display of Oil Rate, Oil Volume The proposed image is as shown below.
The present invention operates in four modes as listed below.
1) Oil presets in Volume (e.g. 1 Liter. Petrol with 20 ml. Oil)
2) Oil presets in percentage (%) & Petrol preset in volume /Rs. (e.g. 5% oil for 1 Liter. Petrol)
3) Oil presets in Rs. (e.g.1 Liter. Petrol with Rs. 10 oil)
4) Fixed presets for oil (shot Pump)

These four modes can be selected by a user by the keypad provided on the side of the pump, top box. The proposed invention is also equipped with optional features like printer etc.
Apart from the above modes, a normal mode is also provided which will deliver only petrol and no oil will be dispensed.
The present invention thus provides the novel features including Electronic oil presets possible Electronic display for oil and Oil bypass (only petrol) is possible.
The present invention accepts the ratio of proportions entered through keypad and automatically convert them into required measurements. The present invention also displays the proportions selected and incrementally display the volume while dispensing. The oil metering is through a gear pump and independent flow meter. The present invention is intended to measure independently each component before mixing, both components gets mixed after metering directly at the point of final dispensing ( i. e at nozzle) This type of arrangement being more flexible helps in metering and delivering independent components as per customer's requirement.
Dated this 31st day of March, 2006.
FOR LARSEN & TOUBRO LIMITED By their Agent
(GIRISH VIJAYANAND SHETH) KRISHNA & SAURASTRI