US1881558A - Carburetor - Google Patents

Description

F. H. HEITGER 1,881,558

CARBURETOR Original Filed Jan. 24, 1928 Patented Oct. 11, 1932 FRANK H. HEITGER, OF FLINT, MICHIGAN GARBURETOR Original application filed January 24, 1928, Serial No.

249,054. Divided and this application filed April l7,

1929. Serial No. 355,955.

This invention relates to improvements in carburetors for internal combustion engines, as used on automobiles and the like, and particularly to the choker or valve on the air a intake of such carburetors, and is a divisional application of'my application Serial Number 249,054, filed January 24, 1928.

Usually, the choke valve of such carburetors is manually closed to obtain a rich mixture for starting, such closing resulting in an abnormall high degree of suction on the fuel jets which are arranged posterior of this valve. After the starting mixture is ob-- tained, in this manner, and the motor commences operation, the choker is released and the choke valve is put in wide open position. In cool or cold weather, should one attempt to run the motor or car with this valve wide open, after the initial start,the mixture, if set normally right, will still be too lean for motor conditions, in consequence of which the driver will close the choke valve again, or set it in some intermediate position that provides a firing mixture to prevent popping or backfiring into the carburetor, but to get the proper mixture (one that will fire regularly without backfiring) requires a different intermediate position of the choke valve for different speeds. This necessitates several settings of this valve in different positions as the motor warms up, and after the motor has warmed up sufliciently, the choke valve can be opened wide.

It is the latter operation of the choke valve which my invention obviates. I intend to employ manual means whereby this valve may e positively closed or choked at the initial starting of the motor,or be positively opened when desired. When the manually operated means isset in an intermediate position, my mechanism is such as to allow the choke valve to operate automatically by suction through the air intake, so that it may operateby suction from a closed to a partly open position; 5 such opening movement being limited by an adjustable stop set by the operator from the dash board of the vehicle. To accom lish this purpose themechanism includes a yielding'calibrated means such as a spring, to resist the opening of the valve by suction,

whereby different speeds and degrees of suction open the valve accordingly, and after the motor is sufliciently warmed up, the choke valve can be set by the manual means in a normal wide open position.

A further object of the invention is to provide means of this character which may be readily assembled or dismantled, and the operation of which may be readily learned by the user of the vehicle. l 63 A further object is to employ means whereby the driver of the car can operate the device satisfactorily and as intended, from the dash, such means including elements to enable the operator to feel when the mechanism is in 6L iintelrmediate operating position, even in the ar r.

A still further object is to incorporate in such means, a thermostatic element which will exert greater resistance to the automatic opening ofthe choke valve, while the motor is cold, than it will after the motor is warmed up.

With the foregoing objects outlined and with other objects in view which will appear as the description proceeds, the invention consists in the novel features hereinafter described in detail, illustrated in the accompanying drawing, and more particularly pointed out in the appended claims.

In the drawing:

Figure 1 is a side view partly in vertical section of a carburetor and dash control means combined with my mechanism. In this view, the choke valve is shown in positively closed position.

, Figure 2 is a top plan' view showing the resilient means for holding the valve closed;

Figure 3 is a transverse vertical section of a view taken on line 2-2 of Figure 1; and

Figure 4 is a perspective view of an operaing member forming part of my invention.

In the embodiment of the invention shown in i gures 1 to 4 inclusive, 1 designates a carburetor having the usual air intake 2, float clamber 3, and fuel inlet connection 4. I have illustratedthe invention in connection with a common type of plain tube carburetor, but it is to be understood that the device can be incorporated into any type carburetor that to move b take 2, and this valve is preferably mounted on a slotted shaft 6 having one of its ends journaled in a bearing 7 on the intake, and its other end journaled in an extension shaft 8. It will be noted that the axis of the m shaft 6 is arranged aboveor off-center, relatively to the axis of the intake 2, so that the lower portion of the valve will always tend gravity into a closed position when suita le control mechanism is in an in-.

termediate position. To aid in such auto matic closing, I provide resilient means which co-acts with the valve so as to keep the valve closed at certain times but will actually resist automatic opening of the same under suction from the engine. The particular construction of this resilient means will be hereinafter fully described.

As heretofore stated, in the present invention, the valve may be positively closed if desired, or'when the control mechanism is in in intermediate'position, the valve may auto-:

matically open, due tosuction, a predetermined limited amountfFor this purpose,

the extension shaft 8 is journaled in a boss "example, diametrically opposite slots 15 to receive the edge of the valve such slots beingsufliciently ,wide to permit the shaft 8 to move-to a certain degree without causing any corresponding movement of the valve. In

' other words,.the slots divide the inner end of the shaft 10 into oppositely disposed jaws 16 which have a loose connection with the sides of the valve 5.

When the parts are in the position shown in Figure 1, the jaws positively engage opposite sides of the valve, and prevent the latter from opening. On the other hand, when the lever 14 has been moved to the intermediate position, not shown, the jaws are so positioned that the valve is free'to rock to some extent from closed to predetermined limited partially open position, under the suction influence of the engine. Further, when the lever 14 has been moved to another limiting position (wide open), the jaws 16 will hold the valve against a stop pin 17 arranged in the intake, and as the result, the valve will be positively held in wide open position.

. It will be noted in the present invention 7 that the valve is normally out of operation. normal operation, mean after the motor is warmed up,the valve is not closed, or should not be.

To enable the operator to control the lever 14: from the dash, such lever is provided with a pivotally mounted knob 18 having an aperture through which an operating rod 19 extends; this rod being locked to the member 18 by a screw 20. The upper end of the rod has a cylindrical enlargement 21 which slides in an aperture 22 in the dash board 23 of the vehicle. As best shown in Figure 1, the en- 'largement 21 has a longitudinal slot 24 in which a bowed wire spring 25 operates. This spring has one of its ends fixed at'26 to the 'part 21, and it bears against the wall of the aperture 22, so that the, spring assists in holding the parts in any position to which they have "been moved. 'In this form of the invention, the part 21 has a notch 27 which latches on the dash board under the influence of the spring 25, and this construction en- ,1

ables the operator to feel when the rod 19' has been moved to intermediate operating po-- sition, that is, the position shown in Figure 1. The usual hand knob 28 is provided on' the upper end of the part 21.

Normally, the part21 will be in depressed or inward position, as is usual with the choke control handles now in general use, and be positively held in such position. p

The particular construction of resilient and thermostatic means for controlling the position of the valve as shown consists in mounting a ring .30 adjustably on the end of the shaft 6 by a screw 31. The ring m is integral with a horn or finger 32, whic projects. away from the axis of the shaft and engages the freeend of a spring 33, the other end of which is mounted on the carburetor by means of a screw 34 engaging the bracket 35 and adjusted by a set screw as shown. The spring normally in operation has the tendency to hold the valve 1n closed position but yields under pressure and by loosening the screw 33 and adjusting the ring 30 on the 1 0 shaft 6, the tension of the spring can be varied. I preferably make the spring of superposed leaves of suitable metal, two metals of different coefficients of expansion,

so as to form a thermostat and with such a A construction, the spring will exert greater resistance to the opening movement of the valve when the engine is cold than when it is warm.-

When the motor is to be started, if conditions, are such asto require the use of the coke valve, the operator pulls the handle 28 into the position shown in Fig. 1. This positively closes ,the choke valve, and holds it in closed position. Then the engine is turned over either by hand or the usual starting motor, and as no air can enter the intake 2, the suction of the engine will be, immediately exerted on the fuel jet or jets, and an extremely rich mixture will pass to the engine.

After the engine commences to operate, the

Ill

operator of the vehicle moves the handle 28 to the oint where the notch 27 is latched to the ash board. This causes the lever 14 to move to the position shown in Figure 1, and then the valve will automatically open a predetermined amount, limited by jaws 16 and dash control, depending on the suction exerted by the engine.

In cool or warm weather, putting the 0 erating means in intermediate position (t e warm up position) at the start, will choke the air enough for a rich starting mixture, Without the valve being tightly closed.

After the engine has been warmed up sufficiently for normal operation, the handle 28 may be depressed to fully open the valve 6, and to hold the same in such a position.

While the valve is in the intermediate posi tion, and assuming that the motor is running,

suction will tend to open the valve to a de--- gree depending on the suction existing in the intake and opposition of thermo resil ent means, and limited by one or both Jaws 16,

' offer resistance to this opening, and for different speeds or positions, of the ordinary throt tle valve of the carburetor, valve 5 takes up a different position automatically, so that the suction on the fuel jets is at all times sulficient to give a firing mixture, and to prevent backfiring. The mechanism obviates the need of the driver setting the choke control on the dash at different points, for different speeds until the motor is warmed up.

The springs, size of valve, thermo dimensions, the offset position of the shaft 6, are

all calibrated to give the proper results on a given motor, and I have found best results with the resistance to the valve opening from closed to a limited partly open position, to

be such that it would make the mixture somewhat too rich after the motor is warmed up; thereby notifying the driver that the carburetor is still automatically choked, giving him warning to put it in a wide open osition.,

While I have shown and descri ed preferred embodiments of the invention in such manner that they may be clearly understood by those skilled in the art, I am aware that changes may be'made in the details disclosed without departing from the spirit of the invention as expressed in the following claims.

What I claim is i 1. In a carburetor having a single air inlet, a choke valve pivotally mounted on the shaft extending transversely through the wall of said inlet, dash controlled means having a loose connection with said valve for moving said valve into open position, a member ad ustably mounted on said shaft and a thermostatic spring arranged in the path of travel of said member for normally holding said valve in closed position.

2. In a carburetor having a single air inlet, a choke valve in said inlet, a shaft upon which said valve is mounted, a finger carcluding a loose connection arran ed within the intake to permit the valve un er certain conditions to open under suction, said means also including an adjustable element to limit the opening movement of said valve under suction.

, 3. In a carburetor having a single air intake, a shaft extending transversely through said intake, a choke valve carried by said shaft, a finger adjustably mounted on said shaft, a thermostatic flat spring adjustably mounted on the body of said carburetor and adapted to engage said finger for holding said choke valve in closed position, means for holding said valve in open or closed position controlled from the dash, said means including a loose connection arran ed within the intake to permit the valve un er certain In testimony whereof I hereunto aflix my signature.

FRANK H. HEITGER.

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