Title of Invention

A STARTER SYSTEM FOR CARBURETTORS OF INTERNAL COMBUSTION ENGINES

Abstract

A starter system for the carburettor of an internal combustion engine comprising at least one starter jet for metering fuel, a spring-loaded plunger for normally closing the air and fuel passages, characterised by a solenoid and a time delay circuit powered through the ignition system of the engine, whereby, whenever the ignition of the engine is switched ON, the solenoid is energised and the time delay circuit is ON, the energised solenoid drawing the plunger away from its normal position, thus opening the air and fuel passages, to SLtpply a rich air-fuel mixture to the engine, the time delay circuit, after a predetermined interval of time, de-energising the solenoid, thereby allowing the plunger to resume its normal position, under spring-loading, to close the air and fuel passages.

Full Text

This invention relates to a starter system for carburettors of internal combustion engines including carburettors for use with two wheeler and three wheeler motor vehicles. During cold start the engine parts are not hot enough to vapourise the droplets of fuel and ignite the airfuel mixture. This difficulty requires a richer mixture than normally available from the pi lot system. To provide this richer mixture, a starter circuit is, conventionally, added to the carburettor. For instance, in the case of the known starter circuit of the carburettor of a two wheeler motor vehicle, the said circuit has to be manually operated by the user. On the other hand, the starter system, according to this invention, automatically goes into operation for a predetermined period and, thereafter, automatically ceases to operate, without user intervention. Other advantages of the starter system proposed herein will be discernible from the following further description of this invention. The starter system for the carburettor of an internal combustion engine, according to this invention, comprises at least one starter jet for metering fuelj a spring-loaded plunger for normally closing the air and fuel passages, characterised by a solenoid and a time del ay circuit powered through the ignition system of the engine, bihereby, whenever the ignition of the engine is switched ON, the solenoid is energised and the time delay circuit is ON, the energised solenoid drawing the plunger away from its normal position, thus opening the air and fuel passages, to supply a rich ai r-fuel mixture to the engine; the time delay circuit, after a predetermined interval of time, de-energising the solenoid, thereby allowing the plunger to resume i ts normal position, under spring—loading, to close the ai r and fuel passages. This invention will now be described with reference to the accompanying drawings, which illustrate, by way of example, in Fig. 1 the conventional starter system Fig. 2 a sectional view depicting how the air fue1 mixture is supplied to the engine directly, bypassing the venturi of the carburettor Fig. 3 illustrating, by way of example, and not by way of limitation, one of various possible embodiments of the starter system proposed herein. Referring to the drawings, the known starter system (Fig.l) consists of two starter jets Jl J2 to meter the fuel. A plunger P with a flexible seat, such as a rubber seat R, is provided at the bottom of the plunger to normally close the fuel passage F. The plunger itself closes the air passage A. When the plunger P is lifted, manually, the air and fuel passages are opened. While starting the engine, the fuel is drawn, under suction, through the starter jets. The rich air fuel mixture is now supplied to the engine directly, from the fuel and air passages, bypassing the carburettor venturi. When the engine starts, the plunger P is reverted to its normal position, thereby cutting off the rich air fuel mixture to the engine. The engine now runs on the mixture supplied by the pilot system. In the case of the manual system aforesaid, the plunger is lifted, manually, by means of a cable or lever. The user has to maniially pull the plunger up, every time he wants to use the starter system and push it back a-fter the engine starts. In both cases, that is, in the manual system aforesaid and in the system according to this invention, the rich air fuel mixture is supplied directly to the engine, bypassing the carburettor venturi (FiQ.2). In the starter system proposed herein (Fig.3), hawever, the plunger movement is achieved by energising and de-energising a solenoid 5, provided for the said system. The solenoid is energised through the ignition system of the engine. The plunger PI is spring-loaded. When the ignition switch K ON, the solenoid lifts the plunger PI up. The air and fuel passages A1 and Fl being now opened, the rich air fuel mixture is supplied to the engine directly, bypassing the carburettor venturi A time delay circuit D is provided in the solenoid. On the ignition being turned ON, the time delay circuit is turned ON. After a predetermined interval of time set on the circuit D, the said circuit de-energises the solenoid S, whereby the plunger cotnes down, under spring-loading, to occupy its normal position closing the air and fuel passages. The time delay is determined by engine requirements. The actuation and de-actuation of the plunger PI is thus carried out automatically, without user intervention, on the ignition switch being turned ON, without user intervention. In the manual starter system, if the user omits to use the system, cold starting the engine will be difficult. On the other hand in the system proposed herein, the question of the user forgetting to use the system does not arise, because it is operative immediately on the ignition being switched ON. In the manual system, if the user forgets to close the system, once the engine has started, the engine wi11 run continuously on a rich air fuel mixture, thereby resulting in high fuel consumption. On the other hand in the case of the system proposed herein, no such possibi1ity can exist, because the system shuts off automatically, after a predetermined interval of time. The terms and expressions herein are of description and not of 1 imitation, since various other embodiments of the starter system proposed herein are possible, without departing from the scope and ambit of this invention. We Claim: 1. A starter system for the carburettor of an internal combustion engine, comprising at least one starter jet for metering fuel) a spring-loaded plunger for normally closing the air and fuel passages, characterised by a solenoid and a time delay circuit powered through the ignition system of the engine, whereby, whenever the ignition of the engine is switched ON, the solenoid is energised and the time delay circuit is ON, the energised solenoid drawing the plunger away from its normal position, thus opening the air and fuel passages, to supply a rich all—fuel mixture to the engine; the time delay circuit, after a predetermined interval of time, de-energising the solenoid, thereby allowing the plunger to resume its normal position, under spring-loading, to close the air and fuel passages. 2. A starter system as claimed in Claim 1 wherein two starter jets are provided. 3. A starter system as claimed in Claim 1 or Claim 2 wherein the bottom of the plunger is provided with a flexible seat, such as a seat of rubber, for closing the fuel passage - 4. A starter system for the carburettor of an internal combustion engine substantially as herein described and illustrated in the accompanying drawings.

Documents:

0039-mas-2002 abstract-duplicate.pdf

0039-mas-2002 abstract.pdf

0039-mas-2002 claims-duplicate.pdf

0039-mas-2002 claims.pdf

0039-mas-2002 correspondence-others.pdf

0039-mas-2002 correspondence-po.pdf

0039-mas-2002 descriptioin (complete).pdf

0039-mas-2002 description (complete)-duplicate.pdf

0039-mas-2002 drawings-duplicate.pdf

0039-mas-2002 drawings.pdf

0039-mas-2002 form-1.pdf

0039-mas-2002 form-19.pdf

0039-mas-2002 form-26.pdf