US809771A - Automatic speed-regulator for internal-combustion engines. - Google Patents

Description

PATENTED JAN. 9, 1906.

JLG. CALLAN. AUTOMATIC SPEED REGULATOR FOR INTERNAL COMBUSTION EN GIN'ES.

APPLICATION FILED OUT. 23, 1908.

, lnoemor John G. Cal Ian m WA, M

oqttiy witnesses UNITED STATES PATENT OEEICE.

JOHN G. CALLAN. OF LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

Specification of Letters Patent.

Patented Jan. 9, 1906.

Application filed October 23, 1903. Serial No. 178,172.

To all wit/1711, it Hwy concern:

Be it known that I, JOHN G. OALLAN, a citizen of the United States, residing at Lynn, county of Essex, State of Massachusetts, have invented certain new and useful Improvements in Automatic Speed-Regulators for Internal-Combustion Engines, of which the following is a specification.

In stationary-gasengine practice, where constant speed is of prime importance as, for instance, in an electric-lighting plant various governing devices have been employed to maintain constant speed of the prime mover under variations of load on the dynamo. These governing devices may be divided into two general classes-viz., those governors which control the exhaust-valve, whereby its action is regulated so as to retain a portion or all of the burned gases in the engine-cylinder, and consequently regulate the quantity of explosive mixture indrawn at each suction-stroke, and those which reduce the quantity of mixture admitted to the cylinder by throttling the charges or by cutting off the charges at variable points in the stroke of the piston. Each of the latter governors have operated with or without changes in the time of explosive ignition of the charges by regulation of the igniter. Engines equipped with these governors operate with varying degrees of e'fliciency in respect to economy and steadiness of running, and, furthermore, the range of load variation is more or less limited.

My invention relates to an automat1c-governor for regulating the speed of an internalcombustion engine through a large range of load and on a more economical basis. The means which I employ to accomplish these results consists of a device which is sensitive to fluctuations in speed and operates as the speed rises above normal to simultaneously and progressively reduce the quantity of explosive charge taken into the cylinder and advance the'time of ignition until the charge has been attenuated to a predetermined point, after which the quantity of the charge remains constant, or practically so, and the time of ignition is progressively delayed as the speed of the engine tends to accelerate.

The manner of reducing the quantity oi mixture admitted to the cylinder may be either by throttling, by a variable cutting oil of the charges, or by any other suitable arrangement.

This method of governing is especially adapted to heavy stationary work, where the fuel economy is an important consideration, and at the same time the additional advantages of increased thermal elliciency and increased range of operation where the load is variable are obtained.

In the accompanying drawings, which illustrate an embodiment of my invention, Figure 1 is a perspective view of an explosive-engine with my automatic governor shown in connection with a throttle mechanism; and Fig. 2 is a perspective view of a portion of an engine, showing a form of cut-oil mechanism operatively connected with my governor.

I have elected to illustrate my governing device with a single-cylinder four-cycle explosive-engine.

In the drawings, 1 represents the cylinder, and 2 the crank-casing, of the engine. A crankshaft extension 3 projects a suitable distance beyond the casing at one side and carries any approved form of speed-responsive device. The device shown is of the flying-ball governor type 4, which acts in the usual manner upon a sleeve 5, feathered on the crank or intermediate shaft. A bellcrank lever 6, suitably mounted on the engine-casing, engages at the extremity of one of its arms with the movable sleeve 5 and receives a tilting motion therefrom. Loosely carried at the extremity of the other arm of the lever is a swinging transversely-extending beam 7. This beam serves as a connection for separate means which regulate the admission-valve and the circuit-breaker and is a common actuator therefor, as will be hereinafter explained.

The beam 7 is guided in slotted brackets and is adapted to tilt on one or more adjustable fulcrums or pivots suitably arranged to render possible the several steps in the governingoperation. At the right end of the swinging beam an adjustable stop 8 is provided, and at the left end are shown two adjustable spring-actuated pivots or fulcrums 9 and 10. The pivot 10 is arranged intermediate the pivot 9 and the point of connection between the beam and the bell-crank lever 6. The stop 8 is preferably a set-screw which is adjustableby screwing in a bracket 11 on the engine-casing.

Directly over the stop 8 a connecting-rod 12 is attached at its lower end to the swinging beam, from which it extends to the admission-valve mechanism. This latter comprises a puppet-valve 13, a valve-stem 14,

having its end exterior of the casing, a lever 15, forked at one end to engage the valvestem, and a spring 16 on the valve-stem interosed between the forked end of the lever and the head of the stemv The free end of the lever 15 piv-otally connects with the connecting-rod 12. By means of this arrangement tilting of the beam under the action of the governor imparts motion to the lever 15 through the medium of the connectingrod. When the lever 15 is drawn down at its free end, the effect is to increase the tension on the admission-valve spring. According to the degree of tension placed upon the spring of the admission-valve the opening of the admission-port is correspondingly varied and the charge of explosive mixture consequently throttled. Any suitable throttling mechanism may be employed in connection with the present governing device, as the scope of the invention is general in this respect.

Arranged above the left end of the beam 7 is a circuit-breaker 17 which is mounted upon a secondary or half-speed shaft 18. The circuit-breaker comprises a supporting-disk 19, a brush'20, attached thereto, and a commutator 21. The supporting-disk is loosely mounted on the secondary shaft, so as to shift under the action of the swinging beam. For this latter purpose the supporting-disk is connected, preferably, at a tangential point with a link 22, which in turn connects with the beam 7. In case the beam 7 is caused to swing at its left end the supporting-disk is shifted to change the relative position of the brush with the commutator, so that the circuit is made and broken early or late to vary the time of ignition of the charge. Any approved ignition system may be used. The details of the electrical apparatus employed for this purpose are not shown in the present instance.

The pivot 9 is disposed directly under the point of connection of the link 22 with the swinging beam. The pivots 9 and 10 are adjustably supported in brackets 28 on the engine-casing. Each pivot is provided with a knife-edged head 24, and on the shank of the pivot between the head and bracket is a compression-spring 25. This spring tends to hold the knife-edge of the head in engagement with the swinging beam. In some cases of governing the engine it is desirable to use one pivot instead of the other. To permit this, the lower end of the shank of each pivot is threaded, and by means of knurled finger-nuts screwedon the threaded ends of the shanks either of the pivots can be retracted and held out of engagement with the swinging beam, as desired.

Considering the operation of the governing device as so far described, the manner of con-.

.is positively certain.

trolling the speed of the engine will be understood to be as follows: When the speed of the engine increases, due to reduction of load, the ball governor immediately acts upon the swinging beam through the intermediate bell crank lever. In Fig. l the beam is shown as fulcrumed on the pivot 10, on which it initially tilts when the bell-crank lever exerts a downward pressure as the governor is called into operation. By reason of the pivot 10 being disposed between the end and middle of the beam and the bell-crank lever acting on the beam at a central point the left end of the beam is enabled to swing upwardly and the right end to swing downwardly; The effect of this swinging of the beam is communicated to the admission-valve and circuitbreaker, causing a progressive throttling of the charges in the one instance and an advancing of the spark in the other, or, in other words, as the right end of the beam swings downwardly by means of the intermediate members the admission-valve spring is placed under gradually-increasing tension, so that the extent of opening of the admission-port becomes less and less, and accordingly the charges reduce in quantity. At the left end of the beam the .upward movement or swing is transmitted to the brush-supporting disk, shifting the same so as to alter the relationship between the commutator and the brush for the purpose of causing earlier sparking and ignition of the charges. This simultaneous and progressive throttling of the charges and advancing of the spark continues until a predetermined point is reached, when throttling of the charges becomes constant, and further reduction in speed of the engine is accomplished by retardation of the spark. The point where the throttling becomes constant is such that each charge, though considerably rarefied, is of a sufficiently rich combustible composition that explosive ignition Throttling occurs steadily up to this point under the action of the governor and afterward ceases at a point within a margin of sure ignition of the rarefied charges. The point of constant throttle is ascertained experimentally by means of the spring-supported pivot yields to the pres sure of the beam, and thus permits the left end to swing downwardly. As the stop 8 is directly in line with the connecting-rod 12, the admission-valve is unaffected by the beam as it swings, and the only effect derived from the beam swinging is made upon the circuit-breaker. To this end the supportingdisk is shifted oppositely to its initial direction, so that the relationship of the brush to the commutator is such as to cause retarding of the spark. This retardation of the spark is also of a gradual or progressive nature and is intended to continue so long as there is acceleration of speed of the engine. Thus, in general terms, the action of the governing device between normal and full load may be restated as causing simultaneous and progressive throttling of the charge and advancing the spark to a predetermined point, where throttling becomes constant, and further reduction of speed is obtained by progressively retarding the spark.

The above scheme of governing may be slightly modified in respect to maintaining the spark constant while progressively closing the admission-valve to a desired point and then governing further by progressively retarding the spark. This method differs from that described only in respect to the spark not advancing during the throttling operation. In order to adapt the governing device to operate after this manner, the pivots 9 and 11 are readjusted. The pivot 9 is adjusted to a position in operative relation to the beam, and the pivot 10 is retracted so as to permit an unobstructed swinging movement of the beam on the pivot 9 during the throttling period. As the connection of the link 22 with the swinging beam is directly over the pivot 9, no motion is imparted to the circuit-breaker, and consequently the sparking remains constant; but upon reaching the stop 8 the beam swings at its opposite end, i'ulcruming on the stop and depressing at its left end against the spring supporting the pivot 9. This lowering of the left end of the beam causes the circuit-breaker to shift so that sparking occurs relatively and progressively later as the speed of the engine tends to accelerate.

The main principle of my governing device is that of controlling the speed of the engine by progressively reducing the quantity of ex plosive mixture up to a point where the charge is not attenuated to that extent that ignition becomes uncertain and then governing still further by retarding the spark. The reduction of the charge can be effected either by throttling, as hereinbefore ex plained, or it may be by variable cutofl' governing. The variable cut-off mechanism is of any approved form and is adapted to operate progressively in a manner similar to that of throttling, as explained, with either stationary spark or simultaneously progressive advance of the spark.

Fig. 2 illustrates one form of cut-offvalve gear. The admission-valve 26 is opened positively, and variation in the cut-off of the charges is accomplished by means of a sliding cam 27. This cam is arranged on a sleeve 28, feathered on a secondary shaft 29. The cam-sleeve and cam are shifted on the shaft 29 by means of a bell-crank lever 30, suitably supported on the engine-casing, which is adapted to be actuated by the swinging beam through a connecting rod 31. The cam-sleeve is intended to shift progressively when the governor is thrown into operation by variations in speed of the engine. As is obvious, the effect is to vary progressively the point of cut-oil of the explosive mixture. This varying of the point of cut-oil continues up to a certain limit, at which further reduction of the charges would produce attenuated mixtures which would fail to explode. Upon reaching this limit of reducing the charges the cut-oil becomes fixed, and further control of speed is effected by retardation of the spark.

It will be observed that the present governing device enlarges the range of automatic control of the engine and also renders the governing operation economical in respect to a certain saving of fuel.

In accordance with the provisions of the patent statutes I have described the principle of operation of my invention, together with the apparatus which I now consider to be the best embodiment thereof; but I desire to have it understood that the apparatus is only illustrative and that the invention can be carried out by other means.

WVhat I claim as new, and desire to secure by Letters Patent of the United States, is

1. A speed-governing device for explosiveengines, comprisingmeans sensitive to fluctuation in speed of the engine for progressively reducing the charges of explosive mixture to a predetermined point and in further continuation of the governing action for maintaining the charges constant at said point While simultaneously delaying the ignition of the charges.

2. A speed-governing device for explosiveengines, comprising means sensitive to acceleration of speed'of the engine for progress ively reducing the charges of explosive mixture and simultaneously advancing the ignition of the charges to a predetermined point and for then maintaining the charges constant at said point while simultaneously and progressively delaying the ignition of the COD? stant charges.

3. A speed governing device for explosiveengines, which comprises means sensitive to variations in the speed of the engine, and means controlled thereby which during increase in speed above normal first simultaneously varies the charges of the explosive mixture and the time of ignition thereof to a certainpoint, and then varies only the time of ignition of the charges.

4. A speed-governing device for explosiveengines, consisting of means sensitive to variations in the speed of the engine, and means actuated thereby adapted to reduce the charges of explosive mixture, and at a predetermined point adapted to maintain the charges constant and to retard the time of ignition of the charges in accordance with increase in speed of the engine.

5. A speed-governing device for explosiveengines, consisting of a means sensitive to changes in speed of the engine, a single actuating member operatively related thereto, a valve mechanism controlled by the actuating member and adapted to progressively reduce the charges of explosive mixture in accordance with increase of speed, an ignitionregulating device controlled also by the actuating member, and means cooperating with said actuating member for permitting said mechanism and device to progressively and simultaneously reduce the charges and advance the time of ignition or to progressively and successively reduce the charges and retard the time of ignition.

6. A speed-governing device for explosiveengines, consisting of means sensitive to changes in speed of the engine, a swinging beam actuated thereby, a variable cut-oil'- valve gear operatively connected with the beam, adjustable means for arresting the swing of the beam in one direction to limit the variation of the cut-off-valve gear, a circuit-breaker also operatively connected with said beam and adjustable spring-actuated pivots adapted separately to cooperate with the swinging beam to differentially actuate the circuit-breaker.

7 In a governing device for explosiveengines, the combination of a valve for varying the supply of combustible to the engine, an adjustable sparking device for igniting the charge, a speed-responsive means, and a lostmotion connection between the valve, sparking device and the speed-responsive means which first actuates the valve through its range of movement to progressively throttle the charge and then the sparking device, to retard the time of ignition.

8. In a governing device for explosive-engines, the combination of a valve for varying the supply of combustible to the engine, an adjustable sparking device for igniting the charge, a speed-responsive means, and an actuator which under the progressive movement of the speed-responsive means simultaneously moves the valve and advances the sparking device to a predetermined point and is then operatively disconnected from the valve and retards the sparking device.

In witness whereof I have hereunto set my hand this th day of October, 1903.

JOHN G. CALLAN.

Witnesses:

DUGALD MoK. MCKILLOP, ROBERT SHAND.

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