US2393290A - Carburetor - Google Patents

Description

Jan. 22, 1946. M. 5 CHANDLER CARBURETOR 2 Sheets-Sheet 1 Original Filed Feb, 9, 1933 A TTORNEY,

Jan. 22, 1946. M.- E. CHANDLER 2,393,290

' ICARBURE'I'OR Original Filed Feb. 9. 1933 2 Shag-51m 2 INVENTOR. MLTON E. CHANDLER' ATTORNEY Patented Jan. 22, 1946 UNITED STATES PATENT OFFICE Milton E. Chandler, Birmingham,

to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Mich, assignor Original application February a, 1933, Serial No.

Divided and this application October 6 Claims.

This invention relates to carburetors for internal combustion engines and more particularly to control mechanism therefor and has for its principal object the provision of a control mechanism whereby the choke valve and throttle are controlled as a function of engine temperature and/or pressure.

Internal combustion engines using a mixture of liquid fuel and air require a very rich mixture to start, require that the richness be graded down immediately the engine fires and require that the richness of the mixture be very accurately controlled during the warming up period of the engine, particularly if the engine is to be idled at a slow speed before it has reached normal operating temperature. If the idling speed is maintained high, a wider variation in the richness of the mixture will be tolerated. While cold,

Figure 2 is a view similar to Figure 1, showing ainodiflcatlon; and Figure 3 is a; view similar to Figure 1 showing the invention adapted for vacuum actuation.

an engine does not develop full power with a fuel mixture that is correct for idling and steady running and consequently it is desirable to increase the. richness of the mixture for acceleration and heavy loading of the engine.

In the prior art of which I am aware, of which the abandoned application of Hunt and Olson Serial No. 575,025, filed November 24, 1931, and the copending Hunt application Serial No.

630,274, filed August 24, 1932, are examples, provision is made for controlling the richness of the fuel mixture as a function of engine temperature.

The copending application of Elmer Olson, Serial No. 651,589, filed January 13, 1933, and now Patent Number 2,189,219 provides for setting the idling position of the throttle as a function of temperature to prevent stalling duringthe warming up period of the engine.

The present invention improves upon the devices of the prior art by providing a thermostat for controlling the degree of opening of the choke valve as a function of temperature and providing means actuated by vacuum and/or pressure in the engine for modifying the setting of the choke valve to meet particular requirements, this means also controlling the throttle to give a fast idle and prevent stalling.

The invention will be best understood from the detailed description and claims which follow,

-- reference being had to the accompanying drawsure actuation;

is moved. Throttle control lever- It carries a pin Referring now-to the drawings in more detail, in Figure 1 I have shown a plain tube-down draft carburetor Ill having an unbalanced choke valve i2 and a butterfly valve throttle l4 adapted to be rotated by a control mechanism which includes a control lever it fixed upon its shaft i5 and biased in the counter-clockwise direction by a tension spring ii.

The type of carburetor illustrated is shown by way of example. only as the invention may be applied to any carburetor. which has a-throttle -of the type shown. The control mechanism is shown as a separate unit mounted adjacent to the carburetor, this arrangement being shown to better illustrate the invention "and it is to be understood that the control mechanism may be incorporated in the carburetor structure if desired. The mechanism comprises a thermostat is wound'around shaft 19 which carries a lever 2|! that is connected by rod 2! to the control arm 22 of the choke valve. Shaft 19 is journaled for rotation in a suitable bracket 22 upon which a lever 24 is pivotally mounted. The free end of thermostat I8 is connected to lever 24. The thermostat is preferably ofthe type described in S. F. Hunt application Serial No. 647,641, filed December 16, 1932, and is arranged to be tensioned to hold the choke valve closed when the engine is cold and to absorb heat radiated from the exhaust manifold of the engine when it is running. As the thermostat warms up, its tension decreases to permit the choke valve to open, as will presently appear. A fluid tight casing 26 is mounted adjacent to bracket 23 and connected to a source of pres out of the casing. A spring 3i surrounds the rod and is tensloned to urge the diaphragm to the left. Rod 20 carries a pair of pins 22 disposed upon opposite sides of the lower end of lever 24 and adapted'to actuate the lever as the rod 33 adapted to be engaged by a lever 34 that floats upon the shaft l5 and is connected to the end of rod 80. I

when the engine is not running and is cold there is no pressure in casing 26 and spring ll moves the diaphragm to the left and with it rod 20. Movement of rod 30 rotates lever 24 against thermostat. A link It connects lever 24 to lever 48.

When the engine is not running there is no vacuum, and springli pushes piston it down and rotates lever ll counterclockwise on the throttle flnlland'opensthe etostartingposishaftandrotatesleverilclockwiseonitspivot. tin, in which it is shown in dotted lines. The Lever it engages pin it and rotates the throttle, rod-2| by which lever II is connected to the to ill starting position, in which itisshownfin manual throttle control, not shown, is provided full lines. Movement of lever It rotates lever l! with a lost motion connection I! that permits the a counterclockwise. If the thermostat 44 is cold it throttle to be set by rod is without disturbing will be tensioned against lever 45 and movement on; mom getting. Lever It is rotated into the of the'lever will rotate the choke valve position shown in dotted lines and the'tenslon of to close the same for starting. This movement the thermostat is increased. Since the engine is causes rod ii to slide in cylinder 52.. If thermocold, the thermostat is internally tensioned and i stat 44 is hot itwill have no tensionand willnot serves to rotate lever II to close the choke valve engage lever "so the movement of the lever will a and to hold it closedfor. starting. When the ennot-rotate the choke valve. Movement. of lever gine begins firing and builds up oil pressure, It rotates lever 24 to increase the tension 'oftherdiaphragm II is movedv against spring II and mostat "and if the thermostat is cold'it will rod II is moved to the right. Lever II is backed have tension and this movement of lever 24 will oil and throttle closed by spring II to precause arm to rotateto engage rod 2| with the vent racing e engine. Lever 24 is rotated to end of rod 83 so that thermostat II will aid therrelease the tension it places in the thermostat mostat in keeping the choke valve closed. Imsothatthechoke valveisfree toopenpartlally m latelytheengine fires.vacuumisbuilt upin. and grade down therichness of the fuel mix- 20 themanifold and piston It is drawn upwardly in ture. As the engine warms up. the tension of cylinder 41. Lever It is rotated to permit the the thermostat decreases to permit the choke throttle to move to its fully cloud position and'to;

valve open more. and to be fully open when rotate lever 15 to relieve the tension of thermothe engine reaches normal operating temperastat ll. Lever It is rotated to reduce thevten- 25 sion of thermostat it. As long as the vacuum In the modification shown in Figure 2, the carremains high enough to overcome the buretor, choke valve, throttle. pressure casing. o sp in t e pi ton will ma n in operated diaphragm and rod 8| are prcvided'as before. position. Should the vacuum fall, as it will when Thermostat II is connected between shaft II the engine begins to stall and when the throttle is and a suitable bracket in the casing It in which opened to accelerate rapidly. spring ll overcomes it is enclosed A second thermostat II is fixed to the vacuum and moves levels It and It to per- M and abimod i t lover a th t is form the above functions. After the thermostats otaliy mounted upon the thermostat casing have been heated sufiiciently tojhave sero tenu 3 is slowed o u and single 4 sion. movement o1 levers I and It will not close carried by rod 3| registers with this slot. the choke valve. I When the engine is not running there is no While I have illustrated and described specific pressure in casing It and diaphragm is is moved arrangements for r y ng out the teachings of to the left by spring II and with it rod 30 is my invention, 1 have done so y way of example moved. Pin ll rotates lever I! clock-wise. If nly as there are many modifications and the engine is cold, thermostat 38 will be tensioned 4o adaptations that can be made by one skillodxm and its end will shut lever It to increase its the art within the teachings of the invention. tension,.which tension will be added to the ten- This application is a division of abandoned apsion of thermostat it to close the choke valve lillo tlon erial No. 656.016, filed February 9, and hold it closed for starting. If the engine is 1933, in the names of Milton E. Chandler and warm when the pressure in casing 26 dies away, so Scott F. Hunt, and later converted into the sole thermostat II will not be engagedby lever ll application of Scott F. Hunt.

and the movement of the lever will not tension Iclaim: the thermostat Movement of rod III sets the In combina ion with an internal combusthrottle to starting position as before. tion engine carburetor, a choke valve having a In the embodiment of the invention shown in so shaft, a lever fixed on the shaft, a throttle havl'igure 8, the carburetor is provided with a choke ing a shaft. a lever on the throttle shaft, a lever valve II and a throttle It as before. .A thermo--. pivoted to the carburetor. a thermostat for constat element M is fixed to and wound, around trolling the degree of opening of the choke valve shaft ll of the chokevalve and its free end bears as a function of temperature, an auxiliary theragainst a lever ll that is pivotally mounted on mostat fixed tc-the choke valve shaft and enthe air horn of the carburetor. A lever ll floats gaging said pivoted lever. means connecting the upon the throttle shaft and is connected to lever pivoted lever to the throttle lever, means for CI hya rod I. A cylinder 41 is mounted admoving the throttle lever to crack the throttle Jacent to the carburetor and connected by pipe and to tension said auxiliary thermostat to close II to the intake manifold or other source of vacso the choke valve, and means connected to the ham in the engine. A piston 48 fits in the cylthrottle lever and moved thereby for increasing inder and is connected to lever 43 by a rod ill. the tensionof said first thermostat.- A spring II in the cylinder urges piston I! down- 2. A control mechanism for an internal comwardly therein. Thermostat arm ill is fixed upon 'bustion engine carburetor having" a choke valve shaft ll and connected to choke valve lever 22 by and a throttle, comprising a thermostat for con-' rod 2i which telescopes into cylinder 52 that is trolling the degree of opening of the'choke valve fixed upon a rod 58 that is carried by lever I2. as a function of temperature, a diaphragm actu- Thermostat II is fixed to and wound arpund ated by a pressure developed by engine operation, shaft II and its free end hooked over a pin on a rod connecting the diaphragm tothe throttle; lever 24 that is pivotally mounted adjacent to the 10 a spring for moving the rod't'o crack the throttle when the pressure on said diaphragm'i'alls below a predetermined value, and means'com" necting the rod to the thermostat whereby tensions the thermostat as it moves sprin rod.

asoaaeo 3. A control mechanlsmior an internal combustion engine carburetor having a choke valve and a throttle, comprising a thermostat ior con trolling the degree of opening oi the choke valve as a function oi temperature. a diaphragm-actuated by a pressure developed by engine operation, a rod connecting the diaphragm to the throttle, a spring for moving the rod to crack the throttle when the pressure oi said diaphragm falls below a predetermined value, a pivoted lever engagin said rod to be rotated by a movement thereof, and an auxiliary thermostat connected between the lever and said thermostat and tensioned by a spring actuated movement oi the rod to increase the tension oi the thervPatent No. 2,393,290.

MILTONE. CHANDLER It is hereby certified that errors appear in the numbered patent-requiring correction as follows:

for tensionlng the thermostat and partially openin: the throttle.

5. Control mechanism for an internal combustion engine carburetor having. a throttle and a choke valve, comprising a temperature responsive member for yieldingly urging the choke valve toward closed position. and means controlled by pressure developed by operation of the engine to increase the force exerted by the thermostat and to partially open the throttle.

6. In combination with an internal combustio engine carburetor, an air inlet valve, a throttle having a shaft, a lever floating on the shaft and having an over-running connection therewith, yielding temperature responsive means connected to said air inlet valve, and means controlled by a varying pressure developed in the operation of the engine for actuating said lever to rotate the throttle shaft and vary the tension on the temperature responsive means.

MILTON E. cnarmmf Certificate of Correction January 22, 1946.

printed specification of the above age 2, second column, line 48, 5

before 1. In'combination insert the following claims- 1. A control mechanism for an internal combustion engine carburetor having a rotatable throttle and achoke valve, comprising a thermostat for controlling thedegree of o ening of the choke valve as a function of temperature, and pressure contro ed means connected in series with the thermostat for tensioning the thermostat to close the valve and for rotating the throttle I partially open to prevent stalling of the engine. l

- 2. A control mechanism for an intern combustion engine carburetor havin a rotatable throttle and achoke valve, comprising a'thermostatfor contro lin the degree of opening of the choke valve as afunction of temperature, a cy 'nder connected to a source of vacuum in the en e, a piston, means connectingthe piston to the thermostat and to the ottle, andfia ifirinfi for moving the iston when the vacuum at said source is lowto tension e t ermostat to enrich the mixture and to move the throttle from closed position to a partially open position.

3. In combination 'with an internal combustion engine carburetor, a choke valve having a shaft, a lever fixed on the shaft, a throttle having a shaft, a lever floating on the throttle shaft having an over'running connection therewith a lever pivoted to the carburetor, a thermostat fixed to the-choke valve shaft and engaging the pivoted lever, means connectin the pivoted lever to the floating lever, and means for movin the floating ever to crack the throttle and to tension the thermostat and c ose the choke valve. y and for the claims now numbered 1, 2, 3, 4, 5, and 6 read 4, 5, 6, 7, 8 and 9 respectively; in the headin to the printed specification line 9, for 6 Claims read 9 Claims" and that the said etters Patent should be read with these corrections therem that thesame may conform to the record of the case in the Patent Office.

. LESLIE FRAZER, r FirstAm'atant 0mm ofPatmta.

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