US1986574A - Carburetor - Google Patents

Description

Jan. 1, 1935.

F. H. HEITGER CARBURETOR Filed July 21, 1927 2 SheetsSheet 2 1, 1935- I F. H. HEITGER 1,986,574

,CARBURETOR Filed July 21, 1927 2 Sheets-Sheet 1 Patented Jan. 1, 1935 7 1,986,574 oAn UnEroa Frank H. Heitger, Flint, Micln; Mattie G. Heitger, Flint, Mien, administratrix of said Frank H.

Y Heltger, deceased Application July 21,1921, Serial No. 207,486

. 1 Claim. (cl; 251-149) particularly to the choke, valve provided in the carburetor air intake and the invention has for n Fig. 1, a

"Fig. 3 is a'plan'd'evelopment of the blank from one of its objects to provide choke means for the air intake whereby the action of the valve is automatically regulated to afford a more eflicient control of the mixture produced by the carburetor during the period'of warming up a relatively. cool or cold explosive engine. A further object is the provision of choke means associated with the air intake of a carburetor which will ensure a supply of uniformly rich mixture for warming up the engine at all. positions of the throttle and which to a certainextent is subject to manual controlfor varying the degree of richness of the mixture according to the thermal condition of the engine. e 4

Referring to the accompanying drawings wherein an improved embodiment of the invention is illustrated:'

Fig. 1 is a side elevation of a conventionalcar buretor illustrating the invention applied thereto, Fig. 2 'isa partial section on the line 22 of which a part of the control device is formed,

Figs. 4' to 6 inclusive arediagrammatic views showing the various positions which the control device for the choke valve may assume,

vations of the air intake-of a carburetor illus= trating a modified therefor, Fig. 9 is a detail section illustrating the manner of applying additional weight to the counterbalanced valve shaft,.and

Fig. 10 is a fragmentary side elevation of the air intake showing a modification of the invention in which the spring control for the manually actuated arm is omitted.

Referring to the drawings in detail the numeral indicates the conventional type of carburetor including the throttle control arm 6, fuel reservoir 7 and air intake 8 in which the shaft 9 supporting the choke valve 10 is journalled. According to the invention the shaft .9 is located in a plane below the axis of the air intake 8 for a purpose which will hereinafter appear and one end thereof is extended externally as at 11; In the embodiment of the invention illustrated the valve 10 is closed when moved to a position approximately 25 to the vertical although the angle of closing may, as will be understood, be varied as desired.

construction of the control rigidly fixed to the outer extremity 11 of the valve shaft and is weighted at its outer extremity as at 14, the arm 12 occupying such angular position Y with respect to the valve 10 that the influence of the weight 14 normally tends to close the valve thus opposing the tendency of the incoming air to act' on the valve 10 to open the same. The difierentiaLpre'ssure acting on the valve 10 at opposite sides of'the' supporting shaft 9 therefor constantly exerts a pressure on the valve tending to open the latter and this pressure varies accord-, ing to the velocity of mean passing through the intake, becoming less as the'velocity decreases.

1 -he hub part ,13 of the arm 12 is provided with angularly disposed and spaced stops 15 and 16 the extremities of which are turned angularly for engagement with the control'arm 17 which latter is loosely mounted on the boss 18 on the body of the carburetor 5' and movable independently of the shaft9 and arm 12 to a limited degree between the angular extremities o'f the stops 15 and 16, the continued movement of the arm 1'7 after engage: ment with the stop 15 causing the shaft 9 to be so turned as to move the valve 10 to a fully opened position in which further movement is arrested by a stop mg 19 while movement of the'ar'm 17 in the opposite direction after engagement with the stop 16 causes complete closure of the choke valve opening direction under the influence of a spring 20 engaged at one end with said arm and at its opposite extremity with the stop lug 19.

The'weight of the body 14 may be increased as desired by attaching additional bodies 21' thereto as by means of a screw 22 as S gested in Fig. 9 while in the embodiment of the invention illustrated in the drawing the weight 14,.arm 12, hub pr. -.'tion 13 and stops 15 and 16 are struck out from a single blank of appropriate material and thereafter bent along the dotted lines to form these parts asia unit.

According to modern practice in the construction and design of carburetors the latter are so adjusted as to supply a comparatively rich mixture when the throttle isopened wide and a comparatively leaner and more economical mixture in less open positions of the throttle as for normal running and on startingv a cold motor the supply of air to the carburetor must be reduced or shutoff the operation being commonly termed choking the air intake. By thus reducing or choking the air admitted a mixture very rich in 10. The arm 17 is normally moved in a valve 7 Figs. '7 and 8 are fragmentary side and end ele-" fuel is supplied by the carburetor due to the high I suction effect on the fuel jet. After the engine has started, it is customary to reopen the choke valve but if the weather is cold or comparatively so the engine will spit or back-fire into the carburetor dueto the slow burning quality of the lean mixture and this will continue until the motor is comparatively warm. In an endeavor to remedy this condition the driver resorts to adiusting the choke valve to such intermediate positions between open and closed at which the back-fire is caused to stop. However, shouldthe operator then open the throttle wider after having so adjusted the choke valve to supply the proper proportion of fuel for a certain throttle position, there will be an excess of fuel drawn into the carburetor whereas if the" throttle is closed the mixture supply is entirely too lean and unsatisfactory for that reason.

According to the present invention these defects are obviated. In operation, in starting a relatively cold engine the arm 17 is moved by means of the usual dash choke control rod 22 to the'extreme left (Fig. 1) thereby engaging the arm with the stop 16 and carrying the shaft 9 and the choke valve 10 to a closed position thus affording a rich initial starting mixture. When the engine is started properly the arm 17 is moved from the positio'nshown'in Fig. 1 to that shown in Fig. 4 or through an angle of approximately 35 to 40 thus releasing the valve from complete and positive closure, and the suction effect of the differential pressure exerted on the valve 10 causes the latter to open overcoming the effect of the weighted arm 12. With the arm 17 in this position the opening movement of the choke valve 10 is limited by engagement of the stop 16 with the arm 17 thus preventing the choke valve from fully opening or only at to Should the engine be slowed down due to closing movement of the throttle 6, the differential suction efiect on the valve 10 being reduced in proportion to the reduction of the velocity ofair passing through the intake 8 causes the valve 10 to move in the direction of its closed position thus reducing the air passage and further choking the incoming air and thus maintaining a uniformly rich mixture at all positions of the throttle.

The travel of the valve automatically or its range of movement need not be limited to 35 to 40 but may be more if desired by making the stops 15 and 16 wider apart or the arm 1'? on the release may be moved more than 35 to 40. If made for 35? to 40, however, and arm 17 is then moved for instance 50 from a closed position, the valve 10 will still move between 35 to 40 but will still lack 10 to 15 of closing. This, however, would not be a detriment in most cases and for some an advantage, as it would still allow sumcient choking eifect for all speeds and allow more opening for higher speeds. The valve has ample capacity under ordinary conditions and as the valve starts at say 25 this allows 65 opening lacking only 25 of being fully open.

As will be understood the foregoing description relating to the angular movement of the valves is merely presented as an example and is not to be regarded: as restricting the scope of the invention as wide variations may be made therein in' practice.

According to the modification shown in Figs. 7 and 8 the arms 15:: and 16a instead of being carried by the hub of the arm 12 as in the form of the invention illustrateddn Fig. 1, are carried by the arm 17 loosely mounted on the boss of the carburetor body as above described. Further according to this modification of the invention the body or weight 14a; instead of being fornied as a part of the arm 13a is slidably mounted thereon and secured in adjusted position by a set screw 24.

It will of course be understood that various changes in the construction and arrangement of the various parts may be made, as, for instance, the shaft 9 may be arranged either above or below the center of the air intake, and in making such change, it is merely necessary to reverse the arrangement of the parts. Furthermore, the weight 14 may be mounted at a different angle when the valve is closed, so that less resistance is offered to the valves initial opening.

What I claim is:

In a carburetor, a passage having an air inlet, a valve stem extending transversely across said air inlet below the axis thereof, a butterfly choke valve carried by said valve stem within said air inlet whereby a differential pressure is setup by the incoming air tending to open said valve, a. hub member fixed to one end of said valve stem having a weighted arm extending therefrom for normally opposing the opening movement of said valve, said hub member being provided with spaced stops, an oscillating member mounted on a boss formed on the exterior of said-air inlet adapted to cooperate with said stops, a coil spring surrounding said boss having one of its ends fixed and the other connected to said oscillating member for normally tending to move said oscillating member to valve opening position and manual means connected to said oscillating member for moving said member independently of said valve for controlling the position of said valve.

FRANK H. HEITGER.

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