US2160410A

US2160410A - Carburetor device

Info

Publication number: US2160410A
Application number: US83066A
Authority: US
Inventors: August H Blattner
Original assignee: Carter Carburetor Corp
Current assignee: Carter Carburetor Corp
Priority date: 1936-06-02
Filing date: 1936-06-02
Publication date: 1939-05-30
Anticipated expiration: 1956-05-30

Description

May 30, 1939- v A. H. BLATTNER 2,160,410

GARBURETOR DEvIca @y Mali@ May 30;v 1939- A. H. BLATTNl-:R 'I 2,160,410

OARBURETOR DEVICE `Filed June 2, 1956 4 Sheets-Shea?I 2 May 30, 1939. A. H. BLATTNER CAEBURITOR DEVIB 4 Sheets-Sheet 5 Filed June 2, 1936 Patented May 30, 1939 vCARBURETOR DEVICE August H. Blattner, St. Louis, Mo.,v assignor to Carter Carburetor Corporation, St. Louis, Mo., a corporation of Delaware Application June 2, 1936, Serial No. 83,066

Claims. This invention relates to earburetors for internal combustion engines and consists particularly in novel interconnection control means extending between the choke and throttle valves. 5' Inautomatic choke carburetors, it is desirable to provide manual means for modifying the position of the choke valve as otherwise determined by thermostatic and/or suction control devices and also means for varying the limiting position to which the throttle valve may be moved either manually or by means of the usual closing spring.

When the engine is cold, the choke valve in an automatic choke carburetorismaintained substantially closed by the thermostat so as to provide maximum suction on the fuel nozzles during the cranking and warming periods. Occasionally an over-rich mixture is furnished to the cylin ders before the choke valve has opened substantially, due, for instance, to -excessive charges from the accelerating pump caused by repeated deprsing of the throttle pedal or to sticking of the choke valve. 'I'his loading" may be eliminated if the choke valve is quickly opened,

the resulting gust of air serving to clean out the g5 intake system.

When the thermostat becomes heated, the

choke valve is held thereby in its full open position so as to constitute a minimum restriction in the air inlet. Occasionally, when the choke and l0 throttle valves are fully open, as, for instance, when a warm engine is subjected to a heavy load and the atmosphere is cold, there may be a tendency for the choke valve to close slightly, causing 'an undesirable enriching of the mixture.

35 This is due to the low suction in the intake manifold, which is relied upon to draw heated air into the vicinity of the thermostat. It is thus desirable to lock the choke valve in its full open position when the throttle is substantially fully open.

- 40 The throttle valve is normally urged toward its fully closed position by a spring, but during the warm-up period, the engine oil and grease may be abnormally viscous, particularly in cold weather,

u and for this and other reasons, it is desirable that the idling speed of theengine be automatically accelerated during this period to prevent stalling.

Fast idle and unloading devices have heretofore been providedjbut these have been relatively 5d complicated, unsightly, and expensive to manufacture, or not adaptable to automatic chokes.

An object of the present invention is to provide novel, simplified interconnecting means for ca-bure tor throttle and choke valves.

Another object is to provide means for locking the choke valve in its full open position when the throttle valve is substantially fully open.

Another object is to provide a choke and throttle interconnection formed substantially of a single linkage arrangement incorporating fast 5 idle and unloading features, and means for locking the choke open when both the choke and throttle valves are fully open.

Another object. is to provide a'fast idle device having an adjustable unloadingv element formed l0 as a part thereof.

'I'hese objects and other more detailed objects hereafter appearing are attained by the present invention which is characterized substantially by the provision of a fast idle block slidably mount- 15 ed adjacent the throttle operating lever and having an adjustable, curved, unloading lip for cooperating 4with the throttle lever to open the choke when thethrottle is opened to a predetermined extent. motion connection with a control lever rigid with the choke valve. 'I'he choke lever has a lateral extension positioned to overlie the upper extremity of the link when the choke and throttle are substantially fully open so as to lock the choke. i

In the accompanying drawings:

Figure 1 is a side view of a carburetor embodying the invention, 'the valves being shown in the unloading positions.

Figure 2 is'a diagrammatic view showing the choke and throttle valves and inter-connection linkage. A

Figure 3 is a view 'similarv to Figure 1, but

showing the linkage and valves in aldiiferent position, portions of the carburetor :being broken away.

Figure 4 is a diagrammatic view showing the linkage and valv in another position.'

Figure 5 is a view similar to Figure 3, but show- 40 ing the choke and throttle valves fully opened, and f Figure 6 is a view ofthe carburetor taken at 90 degrees to Figuresl, 3V and 5, part. of the structure being broken away.

The carburetor illustrated is of the downdraft type including an air inlet horn l, a mixing chamber 2, and mixture outlet 3 anged as at l for attachment to an engine manifold (not shown). Located in the mixture passageare a series of venturis 5, and a main fuel nozzle .6 opening into the interior of smallest or primary venturi.- An unbalanced choke valve 'I is mounted on pivot 8 Iin the air horn and a throttle valve 9 is mounted on pivot I0 between the mix- The fast idle block has a lostA 20 I ing chamber and the mixture outlet. A crank I I is provided for manually controlling the throttle valve.

Mounted on the outside of the air horn is a housing I2 enclosing aV spiral, bi-metallic thermostat I3, the inner portion of which is secured to the choke valve pivot 8. The outer end of the thermostat may be anchored to the cover portion of the housing I 2 -and the tension on the thermostat 4may be varied by the rotation of the cover. A threaded nipple I4 provides for connecting the 'thermostat housing with a source of hot air, and suction means preferably will be provided for drawing hot air from a stove 35, conveniently mounted on vthe engine exhaust manifold 36, through the thermostat housing. The suction means for drawing hot air from the stove 35 may be of any conventional form, however, the pipe 31 is indicated for suitable connection to any conventional source of connection such as the intake manifold.

Formed-integral with the carburetor body isa fuel bowl I5 in which is located an accelerating pump generally indicated at I9 for spraying raw fuel into the mixing chamber through nozzle I1 when the. throttle is opened.

A rib I8 projecting from the carburetor body adjacent throttle lever II slidably mounts the slotted fast idle block I9 by means of a -pair of screws 20. The fast idle block has a curved lip 2l which may be conveniently formed of a section of metal bent away from the slotted body portion of the block.` Block I9 is pivoted, as at 2'Ia, toa link 22 having a slot 23 in its upper portion loosely receiving a pin abutment 24 projecting laterally from the control arm 25 rigidly mounted on the 'choke pivot 8 between the air horn I and housing I2. Choke lever 25 has a laterally projectinglip abutment 26 at its outer extremity which is adapted to lie above the nub 21 on the upper end of link 22 when both the choke and throttle are' full open." A wlrespring 28 secured to link 22 as at 29, bears against choke lever pin 24 and constantly urges the same against the inner portion of slot 23. The loose'fit between slot 23 and pin 24, and spring 29 cooperate t to cause nub 21 to lle well beneath lip 26 in the locked position, as in Fig. 5.

The operation of the device is as follows: The starting positions of the valves are indicated in Fig. 2 in which the choke is held closed by a cold thermostat, and the throttle is partially opened to the position wherein throttle crank II just touches but does not raise lip 2l on block I9. 'I'he fast idle block I9 is in -the lowest position, supported by top screw 2l, so as to be engaged bythrottle screw 32 during clockwise movement of crank II, to limit closing movement of the throttle to the fast idle `position (Fig. 4). With block I9 held between rib I9 and screw 32, block 23 Vpermits e opening or breathing of the choke valve, to the extent indicated in Fig. 4, to provide sufficient air during the cranking and warm up periods.

In lcase the mixture supplied during the warm up should become over-rich or the engine become loaded for any reason, the choke valve may be manually forced to a partially open position, as

indicated in Fig. 1, by moving the throttle lever II in 'a counter-clockwise direction beyond the position shown' in Fig. 2 so as t-o cause the cam surface 30 on lever II to lift curved lip 2| andv linkage elements I9, 22, whereupon the bottom of slot 23 serves as an abutment to engage and rotate pin 24 and open the choke valve. This causes a gust ofair to pass through the carburetor, cleaning out or unloading the intake system. For unloading, the throttle valve need be opened only momentarily. When the throttle is released to be moved by the usual return spring (not shown) to the idling position, block I9 drops and the choke valve closes as determined by the thermostat. Block I9, having less distance to travel than screw 32, will fully drop before the screw reaches stop rib I8, thus again limiting closing of the throttle to the fast-idle position. The unloading. interconnection is also useful to prevent excessive enrichment or heaviness, as frequently discovered during dynamometer test,- ing, in case the throttle is substantially opened before the engine vis fully warmed. Y

During the cranking and warm up periods, the thermostatically controlled choke will act as an air valve, fluctuating under the influence of varying suction in the carburetor, this movement being permitted by the lost motion connection between choke lever 25 and link 22, even-though block I9 is held as in Fig. 4. As the thermostat becomes heated, pin 24 engages the upper edge 'of slot-23, as shown in Fig. 3, and, if block I9 is fast-idle position, asin Figs. 3 and 5. In this position of the parts, .the throttle valve may be fully closed to the normal idling position with throttle screw 32 engaging rib I8 (see Fig. 3),

released from screw 32, lifts the block from the and the choke valve will eventually be moved by the thermostat to its full open position,as in Fig.

5, and will ordinarily remain in this position until the thermostat is again'closed.

yWhen the throttle is moved to its fully open position, linkage I9, 22 will be lifted to its uppermost position, and held in this position due to engagement between `the lip 2l on block I9 and cam surface 30 on the throttle lever. As the choke valve is fully opened by the thermostat, finger 29 on choke arm -25 is permitted to pass around nub 21 due to looseness between slot 23 and pin 24, and the nub is urged outwardly with respect to pin'24 by spring 29 to insure locking alignment of

elements

26 and 21. Spring 2l also prevents rattling. In the latched or locked position lof the parts, choke lever 25cannot be rotated counterclockwise to close the choke valve as long as linkage I9, 22 is held in its upper position by the throttle lever Il.; The Vchoke valve will be locked in this manner,fas distinguished from the partially opened unloading position shown in Fig. l, onlywhen the choke has .been fully opened by the thermostat and the throttle is also fully opened. Thus two different positions of the choke 'are provided in each vof which it is locked against closing, both requir'mg substantial opening of the throttle valve, but the throttle valve can force the choke only to the4 unloading` position in Fig. l. When lever II is again rotated clockwise to close the throttle valve after the thermostat is heated, linkage I9, 22 will be supported in its upper 'position by the choke valve lever. When the-,thermostat cools, the choke can substantially fully 'close,'even though block I9 in its descent should `engage the upper edge of screw 32.

t Link 22 is provided with 'a restricted, crimped portion 30 for adjusting the length of the linkage to insure thatefast idle block 4,I9 is rendered inoperative at the .proper time relative to the position Vof the choke valve. Unloading lip 2| is also bend' `of the present inventor.

connection mechanism, similar in 'some respects to the corresponding parts described above, is disclosed and claimed in copending applications, Serial No. 666,118 led April 14, 1933, in the names of George M. Bicknell and Otto Henning, and Serial No. 89,088, filed July 6, 1936, in the name Other features vare claimed in a copending application, Serial No. 666,118, led April 14, v1933, in the names 0f George M. Bicknell and Otto Henning.

'I'he linkage arrangement described is simple and economical tomanufacture and eiectively modies the functioning of the choke and throttle valves as required for the fast idle, unloading, and open choke locking conditions. The carburetor parts shown are not essential and various features of the invention may be applied to other types of carburetors, whether of the manual or automatic choke variety and whether having downdraft, updraft, or horizontal mixture passages. Moreover, the interconnecting arrangement itself may be modified in various respects as will occur to those' skilled in the art and the exclusive use of all such modications as come i within the scope of the appended claims is contemplated.' f v I claim:

1. A link for use in a carburetor having choke and throttle valves, said link comprising a sheet metal member having a recess at one end whereby it may be pivotally connected to an adjacent element and having an opening at .the other end adapted to loosely receive a connecting pin, said link being provided with a pair of slitted and bent portions between said recess and said opening, one

of said portions serving for adjusting the length of said link, and a spring member mounted in the other oi.' said slitted and bent portions and having one end disposed adjacent said opening for takingy up lost lmotion between said opening and a connecting pin therein.

2. In a carburetor, choke and throttle valves. pivoted control levers for said valves, interconnection linkage having a pin and slot lost Vmotion connection with the choke lever and an abutment structure adjacent said throttle lever for I' engagement thereby when said throttle valve isI opened to move said linkage, said choke valve being capable of -opening and closing movements independently ol said linkage when said throttle valve is opened, said choke lever including a 1at "eral lip spaced outwardlybeyond the pin and slot connection, and said interconnecting linkage having an abutment disposed to underlie said lateral lip when said choke valve is substantially fully opened, and a spring device for causing said linkage to interlock with said choke level' when both gagel the otheryof said members, said other member having a portion adapted to be engaged 4by said abutment when both valves are open to prevent closing of the choke valve while the throttle remains in open position. f

4. A device of the character described in claim 3 and furtherincluding a connection operative by the throttle when the choke is in substantially closed position to insure the movement of the choke valve to an only partially open position when the throttle valve is completely opened.

5. A device of the character described in claim 3 and furtherincluding a member operable by a full opening movement of the throttle valve for insuring the opening of said choke valve at least to a predetermined partially opened position.

AUGUST H. BLA'ITNER.