US2446352A - Automatic choke - Google Patents

Description

' 2 Sheets-Sheet l INVENTOR ATTORNEY muh, Wwmw@ 2 Y Q MN Wm, O\ a. m W

Filed June 8, 1946 Aug. 3, 1948. A. G. WINTER 2,446,352

AUTOMATIC CHoKE l Filed June 8, 1946 `.2 sheets-sheet 2 160 170 180 190 ZOO 210 ZZO 230 240 Z50 I0 20 50 40 50 60 70 80 S0 .100 110 120,150 140 150 TEMPERATURE IN DEGREES F. F7-22 NaOH als Nr 319m; A Lv'a smoHp Ssdbcr ATTORNEY A.Patented Aug. 3, 1948 .'.AUTOMATIC CHOKE- G. Winter, `Pleasant Ridge,

Mich., .assignor to 'Georgie M. Hlley and lEarl Holley Applican 3111188, 1946, Serial N0. L"675509 111132151115.` (CL-1234117791) `The object of this jinvention is .tc improve lthe action of an ordinary thermostatioailly controlled choke :modi-ed by `:electro -magnet now in `general use.

These chokes respond to the flow of the elec- .tric cuir-ent through `a starting motor -to Aenergize an electro-magnet. energized electromagnet 4then closes the-choke so -thatthe moment the current ceases to eflow the thermostat acts alone and .imposes only a weak force tending to close the choke land l"a Amuch stronger force tending to close the choke when the electro-magnet is-enereized.

When adjusted for low temperatures the action of these devices at the -rhigher temperatures vtends tooverchoke. To overccmethis defect is the object ofthis invention.

Fig. 1 isa cross-sectionalelevation of the preferred form of my invention.

Fig. 2 shows the Aelect of the addition of an ancillary thermostat the prior art.

vIn Fig. 1, l is the air entrance, l2 is the choke valve therein, I4 fis the lchoke valve lever. Two independent links 39 and *52 are :pivotaly "connected tothe lever I4. The lower `@end of the link 30 engages witha curved slot 28 in an *element 24 which :slot is approximately concentric with the pin 2:6 upon which the element-.24 rotates. -A pin 32 projects from the surface of thee'lement 24. 'pin -32 engags lwith a stop 34 mounted on the throttle lever I6, which throttle lever |'6 is mounted on the end i 'the throttle shaft of the throttle i8. The throttle lever I6 carries an adjustable idling stop 22 which kengages with a cam shaped surface 20.

The line :38 is iconne'cted `to the throttle lever I and an alternative opening` 40 is provided so that the motion of the link 38 can be increased. A` guide `42 is provided so that a rod 43 is reciprocated downwardly whenever the throttle I`8 is open. The rod 43 is connected to an accelerating fuel pump not shown. Float chamber 44 is provided but again the details of this are not shown as they are no part of this invention. The carburetor is connected to an exhaust jacket fuel entrance 46 which is mounted on an exhaust manifold 48, a cup shaped device 5U is located in the exhaust passage. Another cup shaped device 52 is provided so that between the cup 50 and the inner cup 5'2 there ls a .dead air space to the main thermostat of `which may be partially lled with metal particles. By this means there is a delinite time lag and the temperature rises in the exhaust manifold 48 .before it rises in the cup 52. An inverted kcup-shaped ychamber 53 is provided so as toenclose the space in theicup 52 and provide asubfstantial air chamber which Iagain is heated more slowly than the exhaust 48. The thermostati element l'56 (shaped like `a hairpin) is connected at its lower end to a one way link 58 with lauf other thermostatfic element 60. Theupper end of the hairpin 56 `langages with afroller l0 which is mounted -on a lever plvoted -in the pin. The piny zlill Ais connected "to the lever 112. The lever 12 is connected to the bottom end 'of the-linkZ.

/An iron armature '62 is provided which is `attracted by the electromagnet 4'14, *t6 when-everthe vcurrent :flows through the electro-magnet. The current flows through the .electro-magnet '154, lili whenever the starting motor -86 operates. A Vfoot operated switch allows current to'ilowfin the storage Abattery 82 through the 'electric conductor "lil through the electro-'magnet '14,713 .to ythe ground 90. The major portion of the current meanwhile flows through the brush 84 through the starting motor 86 to the ground 8B.

lIn Fig. 2 the ordinate i-s the degrees of opening of the choke. The choke is fully open at 75. The horizontal line of Fig. 2 is the temperature of the `operative thermostat 456 and the range is from 0F.to 245F. n

vshows the 4elec't of thermostat 55 acting alone without thermostat 60 vand without thesoleno'id yHl so that at 0 F. the choke` valve isfully closed and at point B, which is approximately 1160? F., the thermostat 156 is out of operation and the choke valve is held open -by gravity. That iS. fil? is held open `by the weight of element 24, -arm 12, links 32 and I92 land also-by suction dueto the ollsetoofthechoke valve lf2. l. y

When the .solenoid I4-46 comes into eiect we have the curve CE. The point C *is atapproxlmately 88 and the `choke is still fully closed at this temperature when the solenoid 'and 'the starting motor 86 Iare operative. The choke valve will not be Iwide open under these conditions until point E which is approximately 245 This is the prior ar-t.

The result of the addition of 'the ancillary thermostat '60 is to lchange Ithe characteristic of the curve @E to FG or to C-D. The difference between CD and FG 'is determined by the characteristic of the thermostat "60. When 'the solenoid is operative `and both Ithermos-tats `56 yand 60 are operating then the choke valve will be fully closed at a @temperature of yapproximately to 88 F. which rare points Fand C, as the case may be, and they lwill be fully open at approximately 180 F. (point G) or at 200 F. y(point D).

'Operation In the ordinary operation of the carburetor in starting a cold engine the switch 'B0 is closed and.

immediately the electric motor 86 starts to crank the engine. -At the same time the amature 62 is attracted upwardly by the ele,ctro-magnetv 'I4- 15. This means that 'the'lever 12 is 4,also raised which closes the choke l2. The moment the engine fires the switch 80 is allowed to open. The electro-magnetic solenoid 14-16 ceases to 4 thermostat receives additional motion from the motion of the said armature and the extent of said motion is reduced as the temperature of the first thermostat is increased, a carburetor, an air entrance therein, a choke valve therein, a choke valve lever therefor, linkage connecting this choke valve lever to the free end of the U-shaped secondthermostat. ,1 2.-Afmixture enrichening device forstarting an internal combustion engine having an electric starting motor, an electric circuit therefor,

a starting switch in said circuit, a source of electricityconnected to said circuit, a second circuit also `connected to said source and also controlled by saidstarting switch, an electromagnet in said second circuit, an armature for said electromagnet,7 a 'thermostat, said thermostat being U- act. The amature B2 is released and the link 5'8 V' descends. The thermostat E0 permits the link 58 to descend so that the hairpin thermos-tat 5B assumes the position'shown permitting the choke valve I2 to open wide. yIn 'cold Weather the hairpin -thermostat 56 expands andthe lever 'l2 is rotated anti-clockwise and the choke valve l2 is partially closed. At Ithe same ltime the'hairpin thermostat 56, under the influence of heat, closes and this tends to open the choke valve l2, so that both ythe ithermostatI 60 and the hairpin thermostat56`, when cold, are deflected so that whenever the engine is started by depressing the foot operated switch 80 the solenoid 14-16 is energized and the startingof the engine is facilitated by holding the choke valve 'I2 `in a `partially closed position. The degree of closure of the choke being increased by the upward deflection of the thermo- 'stat 50 -when cold. The thermostat '60, however, is lso larranged that it acts only in conjunction with the solenoid M -1,6. The lengthof `the link 58 is adjusted to give the desired result. The link 58 makes a one way connection with the hairpin thermostat 56. p

1. lA mixture enrchening device for starting an internal combustion engine having an electric starting switch in said circuit, a source of electricity connected to said circuit, a second circuit also connectedl to said source and also controlled by said startingv switch, an electromagnet in said second circuit. an armature adapted to be attracted by said electromagnetwhenever the starting switch is closed, a first thermostat connected to said armature, a second thermostat, said thermostat having a U-shape and being pivotedly mounted on the engine having one free end, the other end ofthe U resting on the engine, a link connecting this other' end of the second thermostat with the free end of the iirst thermostat so that the free end ci the U-Shape of the second shaped and pivotedly mounted on the engine, having one free end, .the other end of th-e U resting on said enginaa carburetor, an air entrance thereto, a choke valve therein, a choke valve lever, linkage connecting this choke valve Alever with the free end of the U of saidthermostat, a second thermostat connected to said armature, a link connecting the end of said first thermostat Whichrests against the engine with the free end of saidsecond thermostat so that the free end of the U of the first thermostat receives additional motion from the motion of said armature and the extent of said motion is reduced as the temperature of the said second thermostat is increased.

3. A device as set forth in claim 1 in which there are heating means responsive to the heat of the engine adapted to apply engine heat to the second mentioned thermostat immediately the engine begins to re, indirect heating'means also responsive to the heat of the engine and adapted to apply engine heat to the iirst mentioned thermostat after the second mentioned thermostat has been heated.

4. A device as set forth in claim 2 in which there are heating means responsive' to the heat of the engine adapted to' apply `engine heat to the first mentioned thermostat immediately the engine begins to re, indirect heating means also responsive to the heat of the engine adapted to apply engine heat to the second mentioned ther'- mostat after the first mentioned thermostat has become heated. ARTHUR G. WINTER.'

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

UNITED STATES PATENTS

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