US2770146A - Automotive vehicle control mechanism - Google Patents

Description

Nov. 13, 1956 A. H. WINKLER 2,

AUTOMOTIVE VEHICLE CONTROL MECHANISM Filed July 3, 1952 3 Sheets-Sheet 1 IN V EN TOR.

Nov: 13,. 1956 A. H. WINKLER 2,770,145

AUTOMOTIVE VEHICLE CONTROL. MECHANISM Filed July 5, 1952 3 Sheets-Sheet 4 KWTOAIVE) Nov. 13, 1956 A. H. WINKLER 2,770,145

AUTOMOTIVE VEHICLE CONTROL MECHANISM Filed July 3, .1952 3 Sheets-Sheet 5 INVFIN TOR.

AZWTM WW5? AUTOMOTIVE VEHICLE CONTROL MECHANISM Albert H. Winkler, Elmira, N. Y., assignor to Bendix Aviation Corporation, South Bend, 11141., a corporation of Delaware Application July 3, 1952, Serial NO. 297,042

3 Claims. (Cl. 74-472) The present invention relates to carburetors and more particularly to a control mechanism for carburetors for use on automotive internal combustion engines.

Some types of our present day carburetors are equipped with an automatic choke, fast idle cam, a dashpot, and a kickdown switch for the initiation of a change in transmission speed ratio drive. These elements are arranged to cooperate with the movement of the throttle lever under certain conditions of engine operation and are either controlled by or have an effect on the operation of the throttle of a carburetor. It is, therefore, one of the principal objects of the present invention to provide a compact, relatively simple mechanical linkage for operatively connecting these elements with the throttle. Another object of the invention is to provide. mechanical linkage of the aforesaid type which is easy to maintain in good operating condition and which can readily be serviced whenever the need arises. Fur-ther objects and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings, wherein:

Figure 1 is a side elevation of a downdraft carburetor, showing my mechanism in one operating position;

Figure 2 is another side elevation of a carburetor, showing my mechanism in the same operating position as in Figure 1; and

Figure 3 is an exploded view of my operating mechanism, showing the operative relationship of the various elements constituting the mechanism.

Referring more specifically to the drawings, numeral designates an air horn of a downdraft carburetor, numeral 12 a main body, and 14 a throttle body in which is mounted a throttle (not shown) on a throttle shaft 16. A choke valve (not shown) preferably off-set in the direction to be openable by air flow in the carburetor induction passage is mounted in air horn 10 on shaft 18 and is controlled by an automatic choke unit 20 consisting of a vacuum actuated piston and a temperature responsive thermostatic coil. Hot air is supplied to the choke housing to operate the thermostat from a stove (not shown) on the exhaust manifold of the engine. Mounted on the choke shaft 18 opposite the choke unit 20 is a fast idle cam member 24 which is also controlled by the choke unit during the warming up period of the engine to determine the limit to which the throttle can be closed. A kickdown switch 26 for initiating a change in transmission speed ratio drive of the engine is secured to the main body of the carburetor and is actuated in response to the movement of the throttle. Also secured to the main body is an electrically controlled dashpot 28 for retarding the final closing movement of the throttle to permit gradual deceleration of the engine to normal idling speed. For the purpose of the present description, the automatic choke unit, the kickdown switch and the dashpot will be considered conventional elements and will not be described in detail herein except as is required for a complete understanding of the present invention. The carnited States PatentO F 2,770,146 Patented Nov. 13, 1856 buretor contains, in addition to those elements mentioned, a main fuel discharge system, an idle system, an accelerating pump, a fuel bowl and a power enrichment jet, usually found in conventional float type carburetors, and since the construction of these elements is Well known, description of them here is unnecessary.

The fast idle cam 24 is adapted to rotate freely on shaft 18 and includes a cam surface 30 having a series of notches 32, the purpose of which will be fully explained hereinafter, and a counter weight 34 secured to an arm 36 opposite cam surface 30 for constantly urging the cam in a counterclockwise direction. A lever 38 is rigidly secured to the end of shaft 18 and is operatively connected to the cam by a coil spring 40 mounted on shaft 18 between said cam and lever 38. One end 41 of the spring is hooked around lever 38 and the other end 42 presses against but extends beyond an inwardly extending finger 43 on lever 38. The cam is provided with an outwardly extending finger 44 rotating on a greater radius than finger 43 in the path of end 42 of spring 40 when said spring rotates as the choke valve is moved toward closed position. The cam is thus urged clockwise as the choke valve is closed. A throttle lever 50 is secured to throttle shaft 16 and is adapted to be actuated by the vehicle operator through an accelerating pedal (not shown) and a rod 52 connected to the lower arm 54 of lever 50. A lever 56 is rotatably mounted at its lower end on the throttle shaft 16 between the throttle lever and the end of the throttle body 14 and extends upwardly to a point adjacent the fast idle cam. Lateral movement of lever 56 is prevented by arm 57 on the lower edge of the backing plate 58. A finger 59 on the upper end of lever 56 is adapted to engage the fast idle cam surface when the choke valve is in closed or partially closed position and thereby limit the movement of lever 56 to the left, as shown in Figure 1. Finger 59 is urged away from the cam by a spring 60. A one-way connection is formed between throttle lever 50 and lever 56 by an adjustable screw 61 on lever 50 and an ear 62 on lever 56. As the throttle is closed, the screw engages ear 62 which, together with lever 56 and fast idle cam 24, limits the closing movement of the throttle. When the choke valve is in closed or partially closed position finger 59 engages one of the notches toward the outer end of the cam surface and holds lever 56 at a point further to the right than when the choke valve is open and finger 59 is engaging either hub 63 or one of the inner notches. Hence, when the choke valve is closed, ear 62 and screw 61 prevent the throttle lever from rotating in the counterclockwise direction to the extent that it does when the choke valve is open, thus holding the throttle in a partially open position for fast idling. The notches in the cam surface prevent finger 59 from sliding on the cam surface and moving the fast idle cam toward its slow idle position.

An arm 70 on throttle lever 50 is adapted to engage an ear 72 on lever 56 when the throttle is moved to wide open position and to move lever 56 to the right, as shown in Figure 1, causing a finger 74 on lever 56 to engage the lower arm of lever 38 when the latter lever is in the position shown, i. e. when the choke valve is closed. Further movement of lever 56 and finger 74 to the right causes lever 38 to rotate counterclockwise, thus moving the choke valve to a partially open position for deflooding the engine. When the throttle valve is again closed, finger 74 moves away from lever 38, permitting the choke valve to return to close.

An ear is provided on the upper arm of throttle lever 50 for engaging stem 82 of dashpot 28 as the throttle valve approaches closed position and thereby retards thefinal closing movement of the valve to permit the engine:

to decelerate gradually. In the dashpot shown in the drawings, an electrically controlled valve (not shown) is included in order to render the dashpot ineffective under certain operating conditions. An ear 84 is provided on lever 56 for engaging stem 86 of kickdown switch 26 as arm 70 engages ear 72 and moves lever 56 to the right when the throttle valve is moved to wide open posit-ion.

The accelerating pump of the carburetor is actuated mechanically -by a pivoted lever 88, a rod 90 connecting one end of lever 88 with the throttle lever, and a rod 92 connecting the other end of lever 88 with the piston of the pump. The operation of the pump linkage has no direct effect on the operation of the linkage between the dashpot, kickdown switch and fast idle cam.

In the operation of my mechanism, as the choke shaft 18 is rotated toward choke closed position by automatic choke unit 20, lever 38 and spring 40 are rotated in a clockwise direction causing end 42 of said spring to engage finger 44 of the fast idle cam, carrying said cam in a clockwise direction toward its fast idle position. If the throttle is closed and lever 56 held to the left, the cam will hit finger 59 and stop. Further movement of the choke valve is permitted, however, by the resilient connection provided by spring 40. When the throttle valve is opened spring 60 moves lever 56 to the right, permitting the cam to rotate further toward its fast idle position under the force of spring 40. If the throttle is moved to wide open position while the choke is closed, finger 70 on the throttle valve lever engages car 72 and moves lever 56 and finger 74 to the right, causing finger 74 to engage lever 38 and rotate the choke toward open position. This operation is performed in the event the engine becomes flooded during starting. If the choke is open when the throttle is moved to wide open position, finger 74 passes under lever 38 since the lower arm of said lever is rotated counterclockwise as the choke is opened beyond the reach of finger 74. As the throttle approaches wide open position, car 84 engages stem 86 and moves it in the direction to close kickdown switch 26.

When the throttle valve is closed While the choke valve is in closed or partially closed position, finger 59 engages the cam surface in one of the notches and is held in a position further to the right than when "the choke is fully open, thus causing screw 60 to engage car 62 before the throttle is fully closed. The throttle in this partially open position permits the engine to idle fast while it is becoming warm. As the throttle approaches closed position car 72 engages stem 82 of the dashpot which under certain operating conditions retards the final closing movement of the throttle.

Although a cover for the fast idle cam is not shown in the drawings, one may be used to prevent oil, grease, and dirt from accumulating on the cam and levers 38 and 56. Various changes may be made in the levers comprising my operating mechanism as well as in the arrangement of the levers without departing from the scope of the present invention.

I claim:

1. The control mechanism for the throttle of a carburetor having a choke valve, a shaft for said valve, a throttle and a shaft for said throttle, comprising a lever rigidly secured to said choke shaft, a fast idle cam adapted to rotate on said choke shaft, a spring operatively connecting said lever and cam, a throttle lever rigidly secured to said throttle shaft, an adjustable stop member on said throttle lever, a control lever rotatably mounted at one end on said throttle shaft and adapted at the other end to engage said cam, 2. lug on said control lever forming a one way connection with said stop member and forming the sole limitation to the closing movement of said throttle.

2. A control mechanism for the throttle of a'carhuretor having a choke valve, a shaft for said valve, a throttle and a shaft for said throttle, comprising a lever rigidly secured to said choke shaft, a fast idle cam adapted to rotate on said choke shaft, a spring operatively connecting said lever and cam, a throttle lever rigidly secured to said throttle shaft, a control lever rotatably mounted on said throttle shaft adjacent said throttle and adapted'to engage said cam, means forming a one way connection between said control lever and said throttle lever, means on said throttle lever formed to rotate said control lever only when said throttle valve has been opened a predetermined amount, and means on said control lever for engaging the lever on said choke shaft for opening said choke when said control lever is rotated by said last mentioned means.

3. A control mechanism for a carburetor having a kickdown switch mounted thereon comprising a choke valve, a choke lever operative'ly connected to said choke valve, a throttle, a throttle lever operatively connected to said throttle, a control lever rotatably mounted adjacent said throttle lever, abutment means on said control lever adapted to engage said choke lever and switch, and an arm on said throttle lever adapted to move said control lever into engaged position with said choke lever and switch when said throttle is opened a predetermined amount.

References Cited in the file of this patent UNITED STATES PATENTS 2,166,899 B'lattner July 18, 1939 2,218,699 Coffey Oct. 22, 1940 2,306,824 McKechnie et al Dec. 29, 1942 2,373,902 Matulaitis Apr. 17, 1945 2,402,361 Bicknell June 18, 1946 2,478,613 Weber Aug. 9, 1949

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