US2148729A - Carburetor throttle control - Google Patents

Description

l. E. coFFEY 2,148,729

CARBURETOR THROTTLE CONTROL Feb. 28, I1939.

Filed June 24, 193'? 2 sheets-shewu 1 lNvENToR. ffl/N f, fa/:ffy

ATTORNEY.

Feb. 28, 1939.' v 15E. coFFl-:Y

I CABUR'TOR THROTTLE CONTROL 2 Sheets-Sheet 2,

Filed June 24, 1957 JNVENTOR Z@ XM f m m Penas, 193s I 2.148.129 .caasnaa'roa rnnomn oon'raor.

n-ven E. ceney, sauna, Mo.. suine: te omer Carburetor Corporation, St. Louis, Mo.,` a oorporation of Delawarev Application June 2.4, mi, serial No. 15am v'I'his invention relates to carburetors for automobile engines and consists particularly i'n,

novel throttle control means therefor.

Modern automotive carburetors are usually si provided with means for increasing the richness of mixture supplied when the associa engineV is being subjected to abnoneuy' heevy loads. Such. condition is ordinarily accompanied by substantial opening of the throttle valve and l relatively low suction in the intake passages. 'Ihe additional richness may be obtained by means' for increasing the enective size of the main metering orifice or by a device for opening an auxiliary fuel supply to the mixture conduit and v --lli the auxiliary enrichener may be controlled manually with the throttle valve or -by means'of a suction actuated mechanism. In the case of a manual enrichener such as a throttle-controlled stepped metering rod cooperating with the main 20 metering orifice, the power step of the metering rod must necessarily be brought into operative relationship with-'the metering orlnce whenever the throttle is opened to the predetermined de-` gree regardless of'the rate of speed or the load 25 vapplied to the engine. v'I'he additional richness provided by the power step" at low speeds is es- `.sential for obtaining maximum power from the engine, but during acceleration and high speed operation, thisl extra richness .accounts for only" 30 slight if any essential.

'nie' average automobile driver rarely subjects improved perfomance and is not his engine to c'onditionarequiring maximum power `and, accordingly, seldom actually needs the 35 additional richness which accompanies full opening of the throttle valve. Such a. driver is ordi- .narily not suiliciently skilled to operate the throttle valve in the most economical manner. though it could be so operated without noticeably af- 40 fecting the operation of his car. Consequently, when he desires rapid acceleration or increased power, lie depresses-his throttle pedal ymuch more than is necessary and wastes fuel.

yAn oblect 'of the present invention is to\pro- 45 vide means for selectively limiting the degree to which the carburetor vthrottle valve may bev opened.

.Another object is to provide manual means for varying the eifectlve relationship between the 50 throttle and its control pedal or lever.

Another object is to provide automatic means for limiting the degree towhich thethrottle .valve may be opened when normal driving conditions prevail while permitting greater or full 56 opening of the throttle under other conditions.

hereafter appearing are Still another object is to provide means for making operation of the throttle valve easier for city or other driving when repeated variation of the throttle position is necessary.

'I'hese objects and other more detailed objects attained substantially by the devices illustrated in the accompanying Fig. '1 is a view. partly in section.. showing parts of an internal combustion engine and carburetor control mechanism therefor.

Fig. 2 is a' view of the mechanism taken on line 2--2 of-Flgure'l, the flooring being omitted.

Fig. 3 is a section taken substantially on line 3-3 of/Figure 2.v

Fig. 4 is a view similar to Figure 1, but showing a modification.

Fig.5 is a diagrammatic 4representation showing operative parts of a carburetor and another drawings, in which:

form of the invention.

Fig. 6 diagrammatically illustrates still another form.

Figures 1 and 4 show a portion of internal combustion engine I. of the usual automotive type, having exhaust manifold 2 and intake manifold 3 merging in hot spot vconstruction 4 for applying exhaust, heat to the intake gases. Moimted'on the hot spot is a carburetor, generally indicated at i, having a throttle valve 6' mounted near the ouuetporuon thereof.' As. show n in'Figure 5, the carburetor also icludesf a downdraft -mixture conduit at l, venturis 8, choke valve 9. and main nozzle lli. Adjacent the mixture conduit is a constant level .chamber il .having thev usual float controlled inlet valve mechanism (not shown).

Fuel is supplied to main nomle It through metering orince member I2 and accelerating fuel is supplied from pump Il. The en'ective size of` orince member I2 may be varied by movement of the stepped metering rod I4 carried by rock lever I5 manu'- ally controlled with thev throttle valve through link I l and arm l1 rigid with the throttle shaft.

Accelerating pump Il is also manually controlled from the throttle.

Pivoted to` a bracket Il projecting from the flooring or frame adjacent the drivers seat is a rock lever -Il connected at one end. with the throttle arm Il by means ofa link 20. The opposite extremity of lever il is provided with a slot 2i which slidably receives the bent over end portion 22 of'push rod -23 secured at its upper end to theusual throttle control pedal 24, Rod 22 passes through an opening 2l in the flooring 2C.'

A p intle 2l depending from a portion of floor- REISSUED4 DEG 3 1940 mg zsspaced'iaterauy from rock lever is pivo'tallyj'mlounts .a lever 26 extending substantially ata rightangle to lever |9 and paralleling flooring 26. Lever 28 is yieldably held in position wishes to obtain maximum economy which alccompanies restriction of the degree to which the throttle may be opened, lever 28 may be manually rotated counterclockwise, with reference to Fig. 2, so as to move push rod 23 to the outer extremity of slot 2|. Such movement increases the leverage relationship between the throttle valve and its control pedal, or,-in other words, varies the mechanical advantage of the throttle control mechanism so that full movement'of pedal 24 produces only partial opening movement of the throttle valve. Obviously the maximum degree to which the throttle may be opened by the pedal may be varied by merely moving push rod 23 to different positions in slot 2|. With rod 23 at the outer end of slot 2|, the throttle valve can be opened only to the position indicatedV in Fig. 5 with the larger orso-called economy step of metering rod I4 still restricting metering orifice.

In Fig. 4 the throttle vcontrol mechanism is the same as that shown in the previous form, and a modified form of mechanism for varying the mechanical advantage between the throttle valve and its control pedal is shown. This mechanism comprises a suction actuated device shown conventionally at 33, in which a. diaphragm (not` shown) is normally urged to the right by-a spring. The suction device is connected to intake manifold 3l by means of a tube 34 in winch is interposed a manual shutoff valve 35. Suction device 33 operates a rod 36 which is connected by means of a pivoted lever 31 to a reach rod or link 33 having an aperture 39 loosely'receiving` throttle push rod 23. This rod is shown in solid lines at the outer end of slot 2l to which position it is moved when relatively high suctions prevail in the intake manifold. In this position of parts, the throttle valve is only partially opened, as indicated at 6a, when pedal 24 is fully depressed. 'Fig. 4 also shows in dot and dash lines the throttlel push rod moved to the inner end of slot 2|'to permit full operation of the throttle, such movement being eected when lsuction in the intake manifold drops below a predetermined value. VValve 35 provides for manually cutting oii suction applied to suction device 33, whereupon push rod 23 will be moved to and held in the' broken line position. The calibration of the suction device and connections shown in Fig. 4k varies with difierent engines. Preferably, device 33 should move rod 23 from the solid line position in Fig. 4 to `the broken line position when the suction in the intake manifold drops from a value corresponding to, say, eight to ten inches of mercury to a value corresponding tofour to seven inches of mercury. Thus, when the suction in the intake manifold exceeds the top suction limit mentioned, which condition prevails during most normal driving, the throttle connections, will be adjusted for the most economical operation. In

case. however, the intake suction drops, as when the engine is subjected to an abnormal load or the throttle is opened quickly. push rod 23 will be automatically slid along slot 2| to permit a greater opening ot the throttle valve. Such a movement of the push rod will also occur in case the engine speed tends to become slower and the throttle pedal is held stationary with the result that the throttle will be automatically opened and -additional power provided.

Figs. 5 and 6 illustrate diagrammatically hydraulic or pneumatic arrangements for operating the throttle valve. In Fig. 5, a valve 40 controls the branched fluid connection between primary cylinder 4|, receiving piston 42 connected to throttle pedal 24 and secondary cylinders 43 and \44 having pistons 45 and 46 connected to throttle arm I1 by balance lever 41 and link 48. Valve 40 has an operating handle 49 easily accessible tc the driver of thev vehicle for connecting primary `tube 50 with either of the tubes 5| or 52. When cylinder 4| is opened to cylinder 43 by means or valve 49, full depression of pedal 24 fully opens the throttle valve. In case valve 40 isset to connect the primary cylinder to cylinder 44,

which is larger than cylinder 43, full movement of the pedal operates the throttle valve only to the partially open position shown with the econ-g v omy step of the metering rod still in the metering orifice. as explained above.

In Fig. 6, a suction device 53 somewhat similar to that in Fig. 4 communicates through tube 54 with the fluid connection 55 connecting hydraulic cylinders 56 and 51. Piston 58 in cylinder 56 is connected to pedal 24 and piston 59 in cylinder -51 is connected to throttle arm i1.

A spring loaded check valve 65 in tube 64 has a restricted central aperture 56 whereby the valve impedes movement of the hydraulic fluid from the 'suction device into connection 55 but oiers substantially no resistance to passage ofv the fluid through tube 54 in the opposite direction.

When a substantial drop occurs in the intake suction communicated to device 53 through con#- duit 60, spring 6| moves diaphragm 62 upwardly. This movement forces a part of the fluid from the suction device into tube ,55 and cylinder 56 fully raising piston 59'and pedal 24. 'Ihis action d oes not aiect the throttle since throttle spring 64 is stronger than spring 63. When the suction device is thus discharged, so to speak, full depression of `pedal 24 operates the throttle since pedal piston 56 is at the top end of its stroke,

and slightly opens the-vthrottle preparatory to restarting the engine. Such automatic reopening oi' the throttle occurs slowly due to the restriction at check 55.

When the intake suction is relatively high as is the c ase under most normal driving conditions, diaphragm 62 will be lowered against spring 6|, drawing uid from connection 55 into the suction device. Thereafter, until the suction again drops, the throttle pedal will be only partially raised when the throttle isofully closed by its return 'spring and consequently depression of the pedal from such position can only partially open the throttle.

carburetor having a metering rod. controlled manually with the throttle valveand the adthe relationship between the throttle valve and the power step of the fuel metering rod. Where the invention is used with the suction step-up type of carburetor, adjustment of the various mechanisms will depend on the suction condition in the intake or carburetor at which the suction step-up device is arranged to provide'the in` creased richness. Suction device Il should move rod 23 to the inner end of slot 2| before the intake manifold suction drops suiiiciently to cause functioning of the auxiliary enriching device.

An example of a i'orm of suction step-up device vis shown in a co-pending application of Leland Read, Serial No. 129,786, illed March 9, 1937. e invention is adapted for application to all" types of throttle controlled, internal combustion engines.

An additional' advantage oi the invention results from the fact that varying the mechanical advantage of the throttle control mechanism not only limits the extent to which the throttle valve l -may be opened" but also makes opening of the 'valve against the throttle return spring (not shown) substantially easier. I'he invention con- .templated broadly varying the mechanical advantage of the throttle control mechanism, however eilected.

lvarious parts of the structures shown are not essential and these may be modiiied as willv occur 'to those skilled in the art. The'exclusive use of all such modifications as come within the scope of the appendedclaims is contemplated.

I claim: i. In combination, acarburetor throttle valve element, a manualcontrol element therefor, and

mechanism for varying the operative 'relationship between said elements comprising a pivoted lever having a recess, a link connecting one ofsaid elements with a portion of said lever spaced from said recess', and a link exte'nding from the other of said elements to said recess and movable"4 therein to vary the leveragerelationship between said eiements.`

2. In combination, 'a carburetor throttle valve, a manual control element therefor, a pivoted lever having a slot. .a link connecting said valve with a portion of said lever spaced from said slot, a second -llnk connecting said control element with said slot, and structure extending from said second link and accessible with said control element for moving said second link in said slot to vary the operative relationship between said control elementfand said valve. 3. The combination of elements specied in claim 2 constructed and arranged so that full movement of said control element is capable of moving said throttle valve only to a partially open position when lsaid second link is in apre-A determined position in said slot.

4. In combination, 'a carburetor throttle valve element, a control element therefor, a pivoted lever having a recess, a link connecting one, of

" maf elements and .portion of nia lever am connecting said elements, and means including a member responsive to suction in said intake structure for varying the mechanical advantage of said mechanism to vary the operative relationship between said elements.

6. The combination of elements specified in claim 4 in which said mechanism and said means are constructed and arranged so that when relatively high suctions prevail in said intake structure, full movement of said control element produces only partial opening movement of said throttle valve element.

' 7. In combination, a carburetor throttle valve, iluid pressure mechanism including a manual control for operating said valve, and means for varying the effective relationship between said control and said valve, said mechanism includingseparate devices operable to provide diii'erentl-operative relationships kbetween said valve and said control. said means'rfunctioning to render said devices selectively operative.

8. In combination, afcarburetor throttle valve,

a manual control therefor, a primaryl'iluid pressure device connected to said control, a pair of secondary iiuid pressure devices connected to said valve', and constructed and arranged to variably translate iiuid pressures transmitted from said primary device, uid connections between said devices. and valve means for selectively connecting primary device to said secondary devices.

9. In combination, a carburetor throttle valve,

a manual 'control therefor. a duid pressure optio'n conditions in the intake of an associated engine.

l0. Structure as speciiled in claim 9 in which said suction operated device functions to vary the effective sise of said connection according to suction conditionsin the intake of an associated engine.

1i. In combination with an internal combustion engine, a carburetor throttle valve. a manual control therefor, and means selectively responsive to operative conditions in the engine f for varying the eiiective relationship between said valve and said control. said means being constructed and arrangedtopartiaiiyopensaid valve when the engine is inoperative.

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