US2705123A

US2705123A - Economizer unit for carburetor

Info

Publication number: US2705123A
Application number: US120731A
Authority: US
Inventors: Robert H Hieger
Original assignee: Individual
Current assignee: Individual
Priority date: 1949-10-11
Filing date: 1949-10-11
Publication date: 1955-03-29
Anticipated expiration: 1972-03-29

Description

March 29, 1955 R. H. HIE GER 2,705,123

ECONOMIZER UNIT FOR CARBURETOF IN VEN TOR.

52 Poberf H. Hlleqer A ttorn eq.

March 29, 1955 R. H. HIEGER 2,705,123

ECONOMIZER UNIT FOR CARBURETOR Filed Oct. 11, 1949 2 Sheets-Sheet 2 mo 9e e4 I ;"/o3

IN V EN TOR.

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United States Patent 2,705,123 ECONOMIZER UNIT FOR CARBURETOR Robert H. Hieger, Detroit, Mich. Application October 11, 1949, Serial No. 120,731 4 Claims. (Cl. 251-61) This invention relates to carburetors for internal combustion engines, and more particularly to an economizer mechanism to enable the carburetor to supply fuel to the engine in increased quantity to increase the power thereof when needed.

Many commercial carburetors as now constructed include a device, usually referred to as an economizer or power jet, which includes a valve controlled by a piston or diaphragm subjected to the vacuum in the intake manifold to increase the rate of fuel supply to the carburetor, and thereby enrich the fuel-air mixture, when the throttle is in or near its fully open position. The valve in such a device is often subject to leakage, which may result in drawing excess fuel into the induction passage at times when it is not wanted, thereby unduly enriching the mixture, with loss of gasoline economy. Leakage through the economizer may result from defective operation of the economizer valve, either because of wear due to vibration or because corrosion or the presence of foreign matter such as grit prevents it from seating properly.

Defective operation of the economizer may also result from a defective or maladjusted valve spring. Thus, if the economizer valve is designed to open at a suction in the manifold of, say, seven inches of mercury, it may open at a lower or a higher suction, causing either a waste of fuel or faulty operation of the engine.

Defective operation of the economizer may result from various other causes, and is diflicult to detect, since commercial carburetors are so constructed that it is impossible, without disassembling the carburetor, to apply a measured amount of suction to the fuel outlet thereof and to the vacuum connection, and measure the resulting fuel flow. Also if leakage is found or suspected, it is diflicult to remedy by means of ordinary shop tools.

An object of the present invention is to provide a carburetor comprising an economizer mechanism having improved means for preventing leakage of fuel therethrough.

A further object of the invention is to provide an economizer wherein the valve is readily replaceable and which will not often get out of proper working order.

A further object of the invention is to provide a car buretor wherein the economizer unit may readily be withdrawn for testing, cleaning and adjustment, and replaced without altering its adjustment.

A further object of the invention is to provide economizer mechanism which is usable in known types of carburetors in substitution for the corresponding mechanism originally supplied with the carburetor.

The invention comprises an economizer of the diaphragm type including a shell or body which, with its contained elements, may be removed as a unit, tested by applying suction, adjusted by means of suitable tools, and replaced in the carburetor without disassembling the unit or disturbing the adjustment.

Further objects and advantages of the invention will be apparent from the following description, taken in connection with the appended drawings, in which:

Fig. 1 is a diagrammatic view of a carburetor and the fuel system thereof showing, on an enlarged scale, the device of the present invention incorporated therein, with the economizer valve in closed position.

Fig. 2 is an enlarged sectional view of the economizer unit and its associated parts, showing the economizer valve in open position.

Fig. 3 is a sectional view similar to Fig. 2, but showing a modified form of economizer unit.

Figs. 4 and 5 are fragmentary views showing the valve unit of Fig. 3 in different adjusted relations.

Fig. 6 is a fragmentary sectional view of a modified form of valve structure.

Patented Mar. 29, 1955 Fig. 7 is a sectional view showing a further modified form of valve structure.

It is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced and carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

This application discloses a device of the same general type as that disclosed in applicants copending application Serial No. 63,598, filed December 4, 1948, now Patent No. 2,537,347, issued January 8, 1951.

The carburetor shown in the drawing is of the downdraft type commonly used with automobile engines, but may be of any known or suitable construction. It comprises a body 8 forming an induction passage which includes an air inlet 10, a main venturi 12, and a mixture outlet 14 designed to be connected to the intake manifold of an internal combustion engine, not shown. The induction passage is controlled in the usual manner by a manually operated throttle valve 16. Usually an air cleaner, such as is indicated fragmentarily at 18, is connected to the air inlet.

Fuel is supplied to the induction passage from a reservoir 20, which in the example shown is a float chamber having a float 22 therein, which actuates a fuel valve 24 controlling a fuel inlet 26 leading from any suitable source of supply. Thence the fuel flows through

passages

28, 30 to the main fuel nozzle 32, which discharges at the throat of the main venturi 12. In the example shown, a second venturi 34 is provided to form a discharge member for the main nozzle. A metering orifice 36 is provided in the passage 28, as is the usual practice, and an idling fuel passage 38 of any suitable construction, may lead from the passage 30 to a point above the fuel level L and discharge adjacent the edge of the throttle 16 when the same is in closed position. Suitable acceleration pump mechanism, as well as check valves, vents, and metering orifices may be provided, as known in the art.

The economizer constituting the present invention comprises a body or shell having a threaded portion 46 which is screwed into a threaded bore in the bottom 48 of the float chamber so that the entire unit may readily be removed from the carburetor. The bottom 48 cooperates with a cover plate 50, secured thereto by bolts 51, to form a vacuum chamber 52 which is connected by a vacuum passage 54 to the induction passage of the carburetor at a point posterior to the throttle 16 when the same is in closed position.

The lower portion of the economizer body is flared to form a recessed base 56 the lower edge 58 of which is spun inwardly to retain a cupped disk 60 having a central aperture 62. A flexible diaphragm 64 has its edges clamped between

members

56 and 60 and is subjected on its underside to the vacuum in the induction passage posterior to the throttle. The diaphragm 64 is formed of an elastomer such as neoprene, manufactured by E. I. Du Pont de Nemours Company, of Wilmington, Delaware, which is highly resistant to gasoline and the acids and other impurities contained therein.

The diaphragm is connected by any suitable coupling 66 to a plunger 68 which is reciprocable within the economizer body, and is of non-circular cross-section to permit fuel to flow therepast. The upper reduced portion of the plunger 68 constitutes a stem 70 which extends through an opening 71 at the upper end of member 46, and is externally grooved adjacent its upper end to receive an annular sealing member or O-ring 72 of the type disclosed in applicants copending application Serial No. 83,688, filed March 26, 1949, now abandoned. The member 72 is of circular cross-section, and is made of material which is capable of elastic distortion under the pressure to which it is subjected, and which is impervious and resistant to gasoline and to the acids and other impurities contained in commercial gasoline. An example of a material which is satisfactory is Buna N, manufactured by Goodyear Tire & Rubber Company of Akron, Ohio, which has also a low friction with metal in the presence of gasoline. The member 72 forms a valve member which, under high or normal manifold vacuum, is moved by diaphragm 64 into contact with the valve seat 74, surrounding the opening 71, to thereby obstruct the flow of fuel therethrough, as indicated in Fig. 1. At lower vacuums, the element 72 is moved, by means hereinafter described, to the position indicated in Fig. 2, to permit an auxiliary flow of fuel through opening 71 and thence to the carburetor.

The bottom wall 48 of the float chamber is formed with an annular recess 80 which communicates with radial ports 81 formed in the portion 46 of the economizer body, and thence with an outlet passage 82 which is connected to passage 30 by a metering orifice 83. Plunger 68 is tubular, the stem 70 being provided with an axial bore 84 which is enlarged as indicated at 86 to receive a stud 87 which is seated therein with a driven fit. The stud 87 forms an adjustable seat for a compression spring 88 the lower end of which seats on a plug 90 in aperture 62 of the disk 60. Plug 90 is formed with an axial bore 91. It will be seen economizer is removed from the float chamber bottom the position of stud 87, and thereby the initial stress of spring 88, may be adjusted by inserting a punch through bore 84 or bore 91 and tapping it to move the stud one way or the other to the desired position. In this manner the valve element 72 may be caused to seat at any desired degree of manifold vacuum, as may be determined by applying a measured degree of vacuum to the bore 91, which acts to transmit the vacuum to the underside of the diaphragm 64.

In the form of the invention shown in Figs. 3, 4 and 5, the body or shell of the economizer is made up of two

parts

96 and 97, secured together in any suitable manner suchas a press fit as shown. A compression spring 98 is mounted in the hollow lower portion of the plunger 100 and urges it upwardly, the lower end of the spring resting against the plug 102 adjustably fitted in a bore in the disk 60 so that the plug may be driven upwardly to increase the initial tension of the compression springT it) Ports 103 in the plug provide communication between the vacuum chamber 52 and the diaphragm 64.

The upper portion of plunger 100 is formed as a solid stem 107 which has a shallow groove to receive a valve element 104 similar to the element 72 in Figs. 1 and 2. The upper end of stem 107 is provided with an adjustable collar 106 which may be press-fitted onto the stem, or may be threaded thereon. Adjustment of the collar downwardly moves the valve element 104 downwardly to cause it to seat earlier on the down stroke of the plunger, as indicated in Fig. 4-; upward adjustment of the collar causes it to seat later, as indicated in Fig. 5, wherein the element 104 is shown moved to an upper position on stem 107 by having been previously displaced by contact with the seat 74.

In the modified form of the invention shown in Fig. 6, the parts are generally the same, and are indicated by the same reference numerals, as in the embodiments previously described, except as hereinafter noted. In this embodiment the stem 70 has a reduced upper portion 108, and the movable valve element is formed of a spherical member 109 retained in place on said portion by a press fit. The member 109 may be of steel or any other desired material.

In the embodiment shown in Fig. 7 the shell or body of the economizer is the same as in Figs. 3, 4 and 5, and a spherical valve element 110 is mounted on the stem 107, and is of the material described as making up the element 72 in Figs. 1 and 2. In this embodiment the valve element 110 is molded on a sleeve 112, of brass or the like, which has a frictional fit with the upper end 114 of the stern 107.

In all forms of the invention, the economizer may be withdrawn from the carburetor, inspected, adjusted so that the fuel valve will open at the desired degree of vacuum, and replaced as a unit in the carburetor without disturbing the adjustment.

Although the invention has been described with reference to certain specific embodiments thereof, it may be embodied in other forms within the skill of artisans in this art and is not limited except in accordance with the terms of the following claims.

I claim:

1. An economizer unit for a carburetor, said unit comprising a body designed to fit in an aperture in the carthat when the buretor and to project into the interior thereof, a valve seat formed on said body in the reservoir-projecting end thereof, said body being provided with a fuel passage, a chamber having a movable wall responsive to varying pressure in the chamber, a plunger connected to said movable wall to be moved thereby, a fuel valve having a sealing element made of rubber-like material resistant to fuel and impurities thereof and carried by said plunger and normally closing said passage at said valve seat but movable by the plunger to open position, a compression spring in said body urging said plunger to open position of the valve, an adjustable seat for said spring carried by said body and adapted to control the initial stress of said spring, said seat being accessible for adjustment from the exterior of the economizer unit, the sealing member being of annular shape and circular cross section and operatively arranged in a circular groove provided on the end of the plunger, the transverse dimension of the groove being substantially larger than the diameter of the cross section of the sealing member, and a retainer member for said sealing member frictionally connected to the end of the plunger and adjustably movable along the same to vary the extreme outward position of said sealing member.

2. An economizer unit for a carburetor, said unit comprising a hollow bell-shaped body having open ends and designed to seat in an aperture in the carburetor and to project into the interior thereof with its smaller upper end, a valve seat formed on said smaller upper end of the body, a rigid wall closing the lower large end of said body, a diaphragm arranged within said body adjacently said rigid wall to form a chamber therewith, said rigid wall being provided with atleast one hole to admit therein pressures existing at the outside surface of said rigid wall, a plurality of holes in the sides of said body for the passage of fuel through said body, a plunger arranged within said body, said plunger having a hollow lower end secured to said diaphragm and its upper end projecting through the open small end of said body, a sealing element made of rubber-like material resistant to fuefandimpnrities thereof and carried by the upper end of the plunger projecting outside of the unit body, said sealing element remaining oiitside ofsaid unit body under all operation conditions, said element" normally closing the fuel passage through the unit body at said seat but movable by the plunger to open position, a compression coil spring operatively arranged within said body and having one of its ends extending into the hollow end of said plunger, said spring being adapted to urge said plunger to maintain said valve open, an adjustment member provided in said rigid wall and adjustably movable therein, said member being adapted to support the lower end of said spring and being accessible for adjustment from the exterior of the economizer unit.

3. The invention defined in claim 2, said diaphragm being secured to said plunger with the aid of a connection including two rigid washers, the upper one of said two washers being adapted to abut against the converging walls of the body and providing a stop for the fully open position of said plunger.

4. The invention defined in claim 2 and including a retainer member for said sealing member, said retainer member being frictionally connected to the upper end of the plunger and adjustably movable along the same to vary positions of said sealing member with respect to the valve seat.

References Cited in the file of this patent UNITED STATES PATENTS 999,109 Howell July 25, 1911 1,366,803 Hofmann Jan. 25, 1921 1,964,249 Chase June 26, 1934 1,982,049 Fageol Nov. 27, 1934 1,995,110 Wahlmark Mar. 19, 1935 2,194,783 Ball et al Mar. 26, 1940 2,250,292 Boyce July 22, 1941 2,316,327 Garretson Apr. 13, 1943 2,408,006 Smith Sept. 24, 1946 2,441,301 Waag et a1. May 11, 1948 2,499,554 Wirth Mar. 7, 1950 2,631,832 Hieger Mar. 17, 1953 FOREIGN PATENTS 657,075 Great Britain 1951