US1519081A - Carburetor - Google Patents

Description

Dec. 9, 1924. l 1,519,081

R. COZETTE CARBURETOR Filed April l2 1920 Patented ec. 9, 1924 UNITED STATES REN cozn'rrn, or COURBEVOIE, FRANCE.

CARBURETOR.

Application filed yApril 12, 1920.

T0 all whom t m04/ concern:

Be it known that l. REN Cozn'rrn. a citizen of the French Republic, residing at No. 43 Rue Louis Blanc, Courbevoiej Seine, France, have invented certain new and useful improvements in Carburetors, of which the following is a specification.

This invention has tor its object to provide an improved 4carburetor designed tor use with internal combustion engines in order to prod ce an explosive mixture in which the proportions ot fuel and air are correctly determined for all speeoa ot the engine.

The improved carburetor comprises two small carburetors of which one, hereinafter described as the low speed carburetor, acts continuously, whilst the other, hereinafter designated as the high-speed carburetor, acts to supply fuel to the engine when the speed ot the engine increases.

The invention consists therefore in a peculiar construction of the high-speed carburetor and in the regulation ot its delivery by means of a valve that is adapted to be operated by the depression occurring in the mixing chamber ot the carburetor.

A constructional form of the improved apparatus is illustrated by way of 'example in the accompanying drawing wherein is illustrated a diagrannnatic vertical section of a carburetor in accordance with the inventi on.

As shown. the improved carburetor is provided as usual with a pipe. o leading to the inlet valve of the engine and in which there is arranged a regulating throttle o. An inlet chamber c formed as a prolongation of this pipe, is in constant communication with a low speed carburetor d provided with a nozzle d1. This chamber is closed at its lower end by a valve c which on being opened establishes communication between the said chamber and the high speed carburetor provided at the nozzle f1 and the Venturi tube g.

The seat oi this valve is constituted` by the upper partof the Venturi tube. 7L which is open at its base to the atmosphere, and communicates through orilices 71 with a chamber j for the iow of the mixture furnished by the high speed carburetor whose nozzle f1 is arranged in the air intake passage f. rlhe guide rod of the valve passes through the top of the chamber c' and carries Serial No. 373,221,

a. piston Z Working in a cylinder m which latter communicates through the orifice n with the atmosphere, and through the orifice o with the inlet chamber. This guide rod 7:: extends also under the valve e and is prefer ably tube-form throughout its length and constitutes a duct Zal which establishes communication between the Venturi tube and the space situated above the upper space ot the piston Zin such a manner as to subject the .latter under certain conditions to the ctt'ects of the depression existing in the carburetor.

It is to be noted that the lower edge of the rod terminates in a plane beneath the most restricted portion of the throat of the Venturi tube. The object of the arrangement is to vary the action on the valve and to brake the valve at low and medium speeds and to raise the valve when the engine is revolving at or about its normal speed.

The improved carburetor operates as tollows 1When the engine is ope-rating at low speed, the valve c being on its seat.. only the low speed carburetor d will be in operation.

At medium speeds, since the depression increases in the chamber c, the valve will be acted upon by two forces, namely an upward force which is a result ot the depression existing in the chamber c and ot the area oit the valve, and a. downward torce which is a result ot the weight ot' the valve and of the action oi the diiierential preesure upon the surface ot the piston Z.

The result that the resistance to the opening ot the valve is determined by the choice of the diameter ot the piston and ot the weight of the valve. lt is to be noted on this point that this resistance must be greater in engines running a high compression than in engines having only a low compression, but that the lifting vtorce ot the valve must always be greater than the braking torce, that is for instance it P be the weight ot the valve; l) the depression existing in the chamber c; S the area of the valve; and S1 the area ot the piston, there must always the venturi to enter said chamber, said air serving to compensate for the increase in the fuel supplied by the nozzle Z1 as a result of the increase in the depression.

if this depressio-n still increases, the valve Will lift a corresponding additional amount, and since the velocity of the air passing thro-ugh the venturi increases, the nozzle f1 will begin to deliver in such a manner as to compensate for the insufficient delivery of the nozzle all, Nevertheless'the lift ot the valve Will be slightly brahed by the depression in the chamber c acting through the orifice 0, and when, the valve having continued its movement, the piston Z Will have reached and closed the orifice n, the depression existing in the Venturi tube vfill art through the duct icl upon the upper surface of the piston and the differential pressure Will assist the rise of the valve.

On a further increase in the speed, the orifice fn, Will be again uncovered, but this time it is uncovered by the under surface ot' the piston, and the admitted air Will destroy the depression which under this surit'ace is exerting a braking o'l the lift of the valve. The differential pressure will then raise the valve quickly to the end of its travel.

The reverse operation Will take place ot course when the engine drops from its normal speed down to low speed.

It Will be understood that this valve does not require the use of any returning spring, and that it moves out of the Way automatically as soon as the engine reaches its normal speed, so that it does no-t create any obstacle in the piping.

llVhat I claim is In a device of the character described, in combination, a throttle controlled inlet pipe forming a main chamber; a medium and high speed carburetor having a Venturi tube and communicating With said chamber; a lov,T speed carburetor communicating With the inner end ofthe chamber, a substantially closed cylinder having a small opening for establishing communication with the top ot the chamber and also provided with a small opening in its lateral Wall near its base for establishing communication With the atmos phere, a piston head operating in the cylinder and coacting With the openings therein, a hollow rod carried by the piston head and depending therefrom and slidable through the casing and having its lower edge normally arranged in a plane beneath the most restricted portion of the throat of the venturi, and a valve carried by the rod controlling the communication between said chamber and the high speed carburetor substantially as and for the purposes set forth.

In testimony whereof I aiiix my signature.

REN COZETTE`

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