US2596429A

US2596429A - Automotive pressure carburetor

Info

Publication number: US2596429A
Application number: US689260A
Authority: US
Inventors: Jr Andrew William Orr
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-08-08
Filing date: 1946-08-08
Publication date: 1952-05-13
Anticipated expiration: 1969-05-13

Description

May 13, 1952 w; JR 2,596,429

AUTOMOTIVE PRESSURE CARBURETOR Filed Aug. 8, 1946 441M Orzwiz:

INVENTOR. W

,H TTORNFY Patented May 13, 1952 AUTOMOTIVE PRESSURE CARBURETOR Andrew William Orr, J r., Detroit, Mich., assignor to George M. Holley and Earl Holley Application August 8, 1946, Serial No. 689,260

The object of this invention is to incorporate in a small aircraft or in an automotive type carburetor the well known features of the large aircraft carburetors now in general use.

Specifically, the object is to modify these well known features and adapt them for use on vehicles such as trucks and for smaller airplane engines.

The figure shows the preferred form of my invention.

In the drawing [8 is the air entrance, [2 is the venturi, I4 is the throttle, I6 is the mixture outlet into which the fuel nozzle 18 discharges. The control of the fiow through this nozzle is the subject of this invention.

2 Claims. (01. 261-51) 28 is a link connecting the throttle [4 with a a cam 24. A link 22 is the manual throttle control. The cam 24 engages with a piston 28 which engages with a spring 28 which engages with a diaphragm 38. Increased pressure is applied to the diaphragm 38 when the throttle I4 is almost closed. 32 is a passage through which the pressure in the air entrance I0 is applied to the upper surface of the diaphragm 30 which responds to 'air fiow by reason of 34 which is an opening through which the suction in the throat of the venturi I2 is applied to the lower surface of the diaphragm 38.

A fuel control element 36 is engaged by the airflow responsive diaphragm 38 and is engaged by the diaphragm 38 responsive to fuel flow. Fuel enters below the diaphragm 38 from an entrance 48. An element 31 engages with the element 38 and controls the flow past a valve seat 54.

A needle valve 42 connected through a lever 44 with the throttle [4 provides the low speed fuel control means. When the throttle I4 is opened any appreciable amount the needle 42 is withdrawn entirely and offers no resistance whatever to the flow of fuel. The resistance then to the flow is that offered by the restriction 48 without the needle 42.

Normally the fuel flows through the restriction 48, through the valve seat 54, past the needle 58 (which when the engine in not running is seated by the compression spring 58), and so to the fuel nozzle l8. A diaphragm 51 is connected to the needle valve 56 to support the spring 58.

Economizer The restriction 18 is effective and enrichens the mixture at wide open throttle (low suction) when the spring 88 opens the valve 68.

Acceleration A piston 10 engages with a spring 12 and dis charges fuel from the chamber 82 past the valve 56 into the nozzle I 8. When the throttle is closed the check valve 84 admits fuel freely to the chamber 82.

Priming In order to get a rich mixture to start, a lever 88 engages with a piston 88 and the piston 88 engages with a spring 88, which spring 98 is seated on the diaphragm 38. When the lever 86 is rotated anti-clockwise the spring 98 is compressed and the valve 36 is depressed so that the fuel freely passes the valve seat 54.

A fuel pump of a well known type 92 driven preferably by an electric motor 94, which receives its energy from a storage battery 96 is provided.

Operation When idling the pressure on the diaphragm 38 is increased by the cam 24 engaging with the spring 28. The fuel thus flows past the needle valve 42 which restricts the restriction 48. The fuel flow through 40-42 creates a pressure drop equal to the spring pressure 28 plus that due to the air diaphragm 38.

As the throttle is opened the needle valve 42 is withdrawn and the cam 24 is rotated so that the load on the spring 28 is removed. The flow of air and fuel then follows a fixed ratio, as the air flow, acting on the diaphragm 38, balances the diaphragm 38 acted on by the drop in pressure of the fuel flowing past the restriction 48. At high manifold pressure (absolute) the restriction 48 is supplemented by the restriction 18 which is in parallel with the restriction 48.

The low speed fuel operation follows an empirical regulation determined by the taper of the needle 42 and the shape of the cam 24. The automatic control follows the removal of the empirical control means.

The priming and warm-up system 86-88-98 has the advantage of providing a richer mixture at wide open throttle where the manifold pressure (absolute) is higher and hence the evaporation is lower than at part throttle when the manifold pressure (absolute) is lower and hence the evaporation greater.

What I claim is:

1. In a pressure type carburetor a source of fuel under pressure, a fuel entrance leadin therefrom, a diaphragm responsive to the pressure of the entering fuel, a fuel passage, a fuel restriction therein admitting fuel to the other side of said diaphragm, a fuel outlet leading from the low pressure side of said diaphragm, a valve in said outlet adapted to open against the fuel flow therethrough, said diaphragm being con: nctedtosaidvalve, an air entrance, a venturi therein; a diaphragm responsive to the. airflow and connected to said fuel valve so as to move in opposition to said first diaphragm, a throttle in the air outlet, yieldable means connected to said throttle imposing a load on said airdiaphragm source of fuel under pressure, a fuel entrance leading therefromka fueldiaphragm responsive to the pressure of "the entering fuel, a fuel passage, a fuel restriction therein admitting fuel-to the other side of said fuel diaphragm, a fuel outlet leading'from the, low pressure. side vof said fuel diaphragm, avalve therein; adapted to be opened :by said' fuel ,r diaphragmaas. it moves. in

response to the pressure drop at said restriction,

, an air entrance, a venturi therein, an air diaphragm responsive to the depression in the throat of said venturi and connected to said fuel valve so as to move it in opposition to the movement imposed on said valve by said fuel diaphragm, an air outlet, a throttle in said air outlet, yield- ,able meansnassociated with .said air diaphragm and responsive only to the closing movement of said throttle for imposing an additional load on said air diaphragm only when the throttle is almost closed, a needle valve connected to said .air throttleand, adapted to enter said fuel restriction only when said air throttle approaches '15' its closed. position.

ANDREW WILLIAM ORR, JR.

REFERENCES CITED The following references are of record in the file of this patent:

v UNITED' STATES PATENTS Number ame Date 2,372,306 :Adair 'Mar. 27, 1945 25 2,390,658 :Mock Dec. 11, 1945 2,392,055 Mennesson Jan. 1, 1946