US2380491A - Switch control mechanism - Google Patents

Description

T. M. BALL July 31, 1945.

SWITCH CONTROL MECHANISM Original Filed Aug. 24, 1940 IN VEN TOR BY 775017145 )7, 342;:

% AT] OR N Patented July 31, 1945 UNITED STATES A PATENT orrica SWITCH CONTROL MECHANISM Thomas M. Ball, Detroit, Mich, Signor to Chrysler Corporation, Highland Park, Mich. a

corporation of Delaware Driginal application August 24, 1940, Serial No. 354,055. Divided and this application August 7,

1941, Serial No. 405,764

14 Claims.

This invention relates to switch control mechanisms and refers more particularly to switch (Cl. ZOO-59) mechanism adapted for control by engine intake simplified governor effect for switch mechanism by utilizing engine intake pressure variation.

A further object is to provide a novel governor eflect, as aforesaid, which will function at pre-' determined amount or position of engine throttle opening under control oi engine intake pressure so arranged as to function independently oi the load on the engine.

Further objects and advantages of my invention will be more apparent as this specification progresses, reference being had to the accompanying drawing, in which:

Fig. 1 is a side elevational somewhat diagrammatic view of a motor vehicle power plant illustrating my invention applied thereto,

Fig. 2 is an enlarged somewhat diagrammatic view of my switch control mechanism.

Fig. 3 is a view similar to Fig. 2 but illustrating a modified arrangement of operating link- 88.

Fig. 4 is a view generally similar to Fig. 2 but illustrating a modified arrangement oi switch control mechanism.

While my invention may be employedln conjunction with various types and arrangements of mechanisms and devices, I have illustrated the principles or my invention in connection with a motor vehicle a portion of which is shown in Fig. 1 having the internal combustion engine A for driving the vehicle through any suitable drive transmitting and speed ratio changing mechanism in casings B and C.

I have illustrated my switch control mechanism for functioning in conjunction with the throttle control mechanism of the engine. By preference the arrangement is such that the accelerator pedal in moving to a predetermined position in its throttle-opening direction exercises a controlling eiiect on the switch mechanism, as when the acmlerator pedal is brought to its fully depressed condition corresponding to approximately fully open. position 01' the throttle valve. The gain in power delivered by the engine during the last Part of the throttle opening movement is so slight thatordinarily this range may be utilized for the switch control without sacrificing car performance where it is desired to eii'ect the switch control under conditions oi maximum throttle opening. However, as it may be desired to provide a distinct switch control range for the accelerator pedal, in addition to it normal throttle-moving range, I have made provision so that my invention is equally well adapted to either arrangement and may even, if desired, be arranged for switch control at any accelerator pedal or throttle position less than that aforesaid.

Referring particularly to Figs, 1 and 2 the accelerator pedal III is yieldingly urged in its throttle closing position of release by a spring ii. The pedal is operably connected by linkage i2 with the lever l3 fixed to shalt I4 which carries the throttle valve l5 positioned in manifold downdraft riser it between the carburetor l1 and manifold distributing branches I8 leading to the various cylinders of the engine. At the top air inlet end of the riser is the usual air cleaner ii. That part 0! the intakesystem which extends above valve I! may be referred to as the atmospheric side or the throttle valve while the parts below the valve extending to the engine may be referred to as the engine side of the throttle valve. when the pedal i0 is fully depressed to position I 0' then lever 13 engages stop 20 and valve i5 5 said predetermined conditions of throttle opening I is fully open as at it.

Associated with my switch mechanism is any suitable electrical circuit system desired to be controlled by the switch mechanism under the aforeand car 01' engine speed. I have illustrated a portion of this electrical circuit at D comprising I ground 2 i thencethrough switch 22, which is closed by lever end 23 when in wide open throttle position 23, thence by conductor 24 to a switch 2.5,

4.5- under predetermined desired conditions oi engine or car speed.

The contact piece 26 is carried by a piston 28 in the form of a diaphragm extending across the outer end of a container 29 forming a chamber a 60 continuously open to riser it so that diaphragm piston 28 is subjected to the vacuum in the ricer on the atmospheric side of the throttle valve. A spring 3| yieldingly urges piston 28 outwardly so as to cause contact piece 26 to close switch II and permit the circuit D to be formed at switch 2! unless however the vacuum in riser It i sumcient to withdraw piston 28 and contact piece It. In the latter instance the switch 26 is open and even though the switch 22 is closed, circuit D will not be formed.

In order tojmagniiy the effect of the vacuum in riser, II and'minimize the sizeof piston 28, while at the same time utilizing structure already used conventionally, and for other practical considerations, I utilise the conventional carburetor venturi I! in down-draft riser I I, the chamber ll being open by a passage 33 to the throat of the venturi.

Chamber 8! thus communicates with the engine intake system at a point between the throttle valve II and atmosphere rather than between the throttle valve II and the engine A so that, for a given throttle opening, the same weight of air will always flow through the carburetor venturi at a given speed of the engine or car in any given drive ratio, regardless of load and other factors. The chamber ll is thus open to the suction in the intake riser at a point anterior to the throttle valve II ratherthan at a point posterior to the throttle valve. For simplicity of disclosure I have not illustrated the gasoline supply jet at the carburetor .venturi throat as the same is well known. Such arrangement provides a governor control on the system D at switch II of great accuracy and simplicity of operation.

In the illustrated arran ement the driver endeavors to control circuit D by closing switch 22 always by manipulatin the throttle valve is to the same position, ap roximately wide open throttle in this instance. because at such time the switch 2! is closed. Therefore whether or not the circuit D will be closed between lead 21 and ground II will depend entirely on the engine or car speed at such time. If the speed is above the desired predetermined value. determined largely by the force of spring 3i and size of piston 2|, then the vacuum at 'venturi I2 acting in chamber 3|! will be sumcient to overcome spring ll and cause switch II .to-open thereby preventing switch 22 from having any effect on circuit D whether switch 22 is opened or closed. whereas if the speed is below such predetermined value then spring II will maintain switch I! closed and switch 22 will alone control circuit D. If. when switch 22 is closed and switch 25 is open. the en ine speed drops down below such predetermined value, then switch II will close as the vacuum falls of! in chamber I. and thereby close circuit D.

In the Fig. 3 modification. the switch 2! is not closed as the throttle valve on openin reaches wide open position but in response to movement of the accelerator edal ilbeyond its wide open throttle position Ill throu h a secondary range of movement to position It" at which time the conductor end portion 21 of throttle lever 34 is at its switch-"closing position 23'. The pedal III is connected through linkage it to bell-crank lever arm 80 loose on the valve shaft N, lever 34 being the other arm of the bell-crank. Fixed to shaft I4 is a lever 31 having a projection 38 urged into continuous contact with lever 18 by a spring I. acting between levers it and 31. The stop ll now engages lever 81 at fully open throttle.

In the Fig. 8 arrangement, depressing pedal II to position I. will result in opening the throttle valve to fully open position ll because the spring ll will cause lever I! to follow the movement of lever 80 and pedal ll. .However. as pedalil is further depressed to the overtravel position Ill". stop II holds lever 21 at tion while swing 80 yields to allow lever It to wide open throttle pool-- close switch'l! as at 28' for closing circuit D vmless, just as in Fig. 2, the switch 2! is open. The Fig. 3 switch control system operates exactly as described for Fig. 2 except, of course, for the overtravel function of the accelerator pedal as noted above.

My invention is also adapted to control elec trical systems wherein the electrical circuit is normally established and adapted to be opened bythe throttle opening means under control of the vacuum intake system. In order to illustrate this general arrangement, I have shown in Fig. 4 .an arrangement which corresponds generally to the foregoing embodiment but which operates with normally closed switch means instead of normally open switch means.

Referring to Fig. 4 I have illustrated such an arrangement in which the switches 22 and 2' are now arranged in parallel with each other in any suitabiecircuit system D, a portion of which is illustrated between ground 2| and conductor 21'. Switch 22 is now normally closed and is opened by the lever end I! of Fig. 2 or Fig. 3 to break the circuit D unless the vacuum at theventuri 12, as before. is such that switch 2! is closed, in which event opening of switch 22 will not break the circuit.

In Figs. 2 to 4 it will be noted that whenever the driver seeks to change the normal condition of switch 22, by closing the same in Figs. 2 and 3 and by opening the same in Pig. 4, the throttle valve H5 in each instance is at a predetermined position so that the vacuum device will, in eiiect. then operate as a fixed function of engine speed and hence car speed in any predetermined drive ratio. If desired. the normal condition of the switch 22 may be changed at less than approximate wide open throttle. Furthermore, by substituting diiferent piston springs for the vacuum operated pistons the illustrated devices may be caused to respond to any desired engine or car speed.

In my specification and claims I use the term "venturi in a broad sense. This device, as well .lmown, increases the velocity and reduces the pressure of the fluid at the venturi throat. The venturi may be of any suitable design to obtain the desired pressure magnifying eflect. Ordinarily a commercial carburetor venturi is formed with frusto-conical portions at each side of the throat as illustrated. The various conductor parts throughout the several views will, of course, be suitably electrically insulated against undesired grounding or interfering with the desired electrical control systems.

In Figs. 2. 3 and 4 the pressure variation at the venturi operates to overrule the effect of the throttle adjusting means in controlling opening and closing of the electrical circuit means at the switch 22. In other words the venturi control renders the switch I: either effective or ineifective to control opening and closing of the circuit means.

I claim:

i. In a control for electric circuit means, an engine having an intake system provided with a throttle valve for controlling air iiow from the atmosphere to the engine. means for adjusting said throttle valve, means for controlling said circuit means, said controlling means comprising a switch-operating element adapted to be operated by said throttle valve adjusting means, and means utilizing pressure variation in said intake system at the atmospheric side of said, throttle valve for and close said circuit means in response to operation of said throttle valve adjusting means. and means utilizing pressure variation in said intake system at the atmospheric side of said throttle valve for rendering said switch means either effective or ineffective to open and close said circuit means in'response to the engine; during its normal operation, attaining a predetermined speed accompanied by predetermined setting of said throttle valve by said throttle valve adjusting means.

3. In a control for electric circuit means, an engine having an intake system provided with a carburetor venturi and a throttle valve for controlling air flow from the atmosphere to the en gine, said venturi being disposed at a point in said intake system anterior to said throttle valve, means for adjusting said throttle valvemeans for controlling said circuit means, said "controlling means comprising a switch-operating element adapted to be operated by said throttle valve adjusting means. and means utilizing pressure variation at said venturi for overruling said control of said circuit means by said controlling means in response to the engine, during its nor mal operation, attaining a predetermined speed accompanied by an approximately fully open se ting of said throttle valve by saidthrottle valve adjusting means.

4. In a eontrol'for electric circuit means, an enginehaving an intake system provided with a carburetor venturi and a throttle valve for controlling air flow from the atmosphere to the engine, said venturi being disposed at a point in said.

intake system anterior to said throttle valve, means for adjusting said throttle valve, switch means adapted to open and close said circuit means in response to operation of said throttle valve ad usting means, and means utilizing pressure variation at said venturi for rendering said switch means either efi'ective or ineffective to open and close said circuit means in response to the engine, during its normal operation. attaining a predetermined speed accompanied by an approximatelv fullv open setting of said throttle valve by said throttle valve adjusting means.

5. In a control for electric circuit means, an encine having an intake svstem provided with a throttle valve for controlling air flow from the atmosphere to the engine, means for controlling said circuit means, and means utilizing pressure variation in said intake system at the atmospheric side of said throttle valve for overruling said con trolling means in response to the engine operating at a predetermined speed under predetermined setting of said throttle valve.

6. In a control for electric circuit means, an en- ;zine having an intake system provided with a throttle valve for controlling air flow from the atmosphere to the engine, switch means adapted to open and close said circuit means, and means utilizing pressure variation in said intake system at the atmospheric side of said throttle valve for rendering said switch means either effective or ineflective to open and close said circuit means duringnormal operation of the engine.

'I. In a switch control mechanism; electric circuit means comprising a pair of switches so ar-.

ranged as to together exercise iunctions of control of said circuit means; an engine having an intake.

system provided with a throttle valve; means operable to adjustably position said throttle valve; means for effecting an operation of one of'said switches in response to predetermined operation of said throttle valve adjusting means in the throttle opening direction thereby to efi'ect a certain function of control of said circuit, means provided that the other of said switches is in a certain one of two position of it operation; and

means utilizing pressure variation in said intake system at a point anterior to said throttle valve for effecting an operation of said other switch to the other of its said two positions of operation in response to the engine, during its normal operation, operating at a predetermined speed above its idling speed accompanied by said predetermined operation of said throttle valve adjusting means such that said certain control function of said circuit means is prevented from occurring in response to said predetermined operation of sai throttle valve adjusting means.

8. In a switch control mechanism according to claim 7; said pair of switches being arranged in series with each other in said circuit means.

9. in a switch control mechanism according to claim 7; said pair of switches being arranged in parallel with each other in said circuit means.

10. In a switch control mechanism; electric circuit means comprising a pair of switches so arranged as to together exercise functions of control of said circuit means; an engine having an intake system provided with a throttle valve and a carburetor venturi disposed at a point in said intake system anterior to said throttle valve; means operable to adjustably position said throttle valve; means for effecting an operation of one of said switches in response to predetermined operation of said throttle valve adjusting means in the throttle opening direction thereby to effect a certain function or" control of said circuit means provided that the other of said switches is in a certain one of two positions of its operation; and means utilizing pressure variation at said venturi for effecting an operation of said other switch to the other of its said two position of operation in response to the engine during its normal operation operating at a predetermined speed above its idling speed accompanied by said predetermined operation of said throttle valve adjusting means such that said certain control function oi. said circuit means. is prevented from occurring in response to said predetermined operation of said throttle valve' adjusting means.

11. In a switch control mechanism, a switch comprising a pair of conductor switch members one of which is adapted for movement relative to the other into positions of engaging and disengaging relationship with respect to said otherof said movable switch member from oneof its,

said positions to the other, an engine having a suction intake system provided with a throttle valvc adapted to be adjusted for controlling air now from the atmosphere to the engine, means for subjecting said pressure responsive member to pressure in said intake system at the atmospheric side or said throttle valve for eflecting diflerentiai pressure movement of said pressure responsive member from its said first position to its said Second position, and means acting to bias said pressure responsive member toward its said first position thereby delaying said difierential pressure movement of said pressure responsive member to its said second position until the engine operates at a predetermined speed above its idle speed accompanied by disposition of said throttle valve in a predetermined position of open throttle adjustment, said biasing means operating to prevent movement of said pressure responsive member from its said first position to its said second position during operation of said engine at speeds below said predetermined speed when said throttle valve is adjusted to said predetermined speed, said biasing means permitting said differential pressure movement of said. pressure responsive member when the engine attains said predetermined speed and said throttle valve is adjusted to said predetermined position.

12. In a control for electric circuit means, an engine having an intake system provided with a carburetor venturi and a throttle valve for controlling air ilow from the atmosphere to the engine, said venturi being disposed at a point in said intake system anterior to said throttle valve, an accelerator pedal for opening said throttle valve,

means accommodating movement, of said accelerator pedal to its position corresponding to approximatelyiully open throttle and therebeyond through a range of movement overtravelling said throttle valve, means for controlling said circuit means in response to movement of said ac celerator pedal in its said overtravelling range, and means utilizing pressure variation at said venturi for overruling said control or said circuit means by said controlling means in response to the engine operating at a predetermined speed when said throttle valve is approximately fully open.

13. In a control for electric circuit means com- 7 prising a switch, an engine having a carburetor venturi, means for operating said switch, and means utilizing pressure variation at said venturi and automatically operating in response to the engine, during operation thereof under its own power, attaining a predetermined speed for preventing said switch operation by said switch operating means.

14. In a control for electric circuit means comprising a switch, an engine having an intake system provided with a throttle valve for controlling air flow from the atmosphere to the engine, means for operating said switch, and means utilizing pressure variation in said intake system 'at the atmospheric side or said throttle valve and automatically operating. in response to predetermined engine speed above its idling speed and predetermined setting of said throttle valve for preventing said operation of said switch by said switch operating means.

THOMAS M. BALL.

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