US2242072A - Load supervisory control means for a mechanical speed governor - Google Patents

Description

May 13, 1941. c. J. HOLSLAG LOAD SUPERVISORY CONTROL MEANS FOR A MECHANICAL SPEED GOVERNOR Filed Feb. 17, 1940 INVENTOR ,q f

2% ATTORNEY Patented May 13, 1941 LOAD SUPERVISORY CONTROL MEANS FOR A MECHANICAL SPEED GOVERNOR Claude J. Holslag, South Orange, N. J., assignor to Electric Arc Cutting & Welding Company,

Newark, N. J.

Application February 17, 1940, Serial No. 319,563

9 Claims.

This invention relates to means for exercising a supervisory control on or over a mechanical speed governor.

In many instances, for example on automotive trucks and special sets comprising internal combustion engines and an electric generator, either for welding or lighting, or other loads, where compressors and other special units are used, the engines have been equipped with mechanical speed governors which are so constructed and interconnected with the engine throttle that the engine is limited to a maximum speed; that is to say, the mechanical governor is set so that the engine will have a relatively fixed top speed at which point the throttle cannot be opened any farther.

It is inherent in mechanical speed governor of the types which have been used on internal combustion engines, as well as on steam engines, that when a load comes on, such as for example on the generator being driven by the engine, the speed of the engine must drop before the governor can start functioning. This characteristic of such governor is highly objectionable for certain classes of work where a constant voltage and frequency, if the generator delivers alternating current, is required; or where a steady or even rising current or voltage may be desired with an increase of load.

It is therefore the principal object of my invention to provide a supervisory control means for an engine mechanical speed governor to prevent a drop in speed as the load comes on and to accomplish the other purposes set forth in the specification which follows, with its appended claims.

In the drawing forming part of the specification,

Figure 1 shows a portion of the forward part of an engine generator set showing my improved supervisory control means interconnected with the engine throttle through the mechanical governor..

Figure 2 is a diagrammatic illustration of a modified form of application of the mechanism shown in Figure 1.

Figure 3 shows a partial view of the application of my invention to a diflerent type of mechanical governor from that shown in Figure 1.

Figure 4 is a view somewhat like Figure 2 but illustrating a modification in which a plurality of generators may be driven by the engine, the generators being connected to the engine governor or throttle through a compensating yoke.

In Figure 1, the engine I is carried on a suitable chassis, a portion of one of the frame members being indicated at 2. The engine I has the usual carburetor 3 and throttle valve 4 connected through a lever 5 to a control rod 6 which in turn is pivotally connected to a main lever I of a mechanical governor 8. Since the construction of the governor 8 per se forms no part of my invention, a description of its internal mechanism does not seem to be necessary except to say that the lever l is moved to the left to open the throttle 4 after the engine has been cranked or started. A drive gear 9 for the governor is indicated, but the gear case and other parts driving the gear 9 are omitted for the sake of clarity.

The governor 8 is provided with an adjustable stop III which limits the movement of the lever I to the left and thereby limits the opening of the throttle 4 so that the engine under the control of the mechanical governor 8 can only run at a predetermined maximum speed. As was pointed out heretofore, with such an arrangement, when the load is applied to the engine through the generator which is mounted on the chassis to the left of the engine, the tendency is for the speed of the engine to drop and the lever I will move to the right and will start closing the throttle 4, which is contrary to what it should do to hold the generator at a constant voltage or frequency, or both, or to give a constant current output.

To overcome this difficulty, I employ an electro-magnet II which, in the form shown, is of the solenoid type having a movable core or member I2 which is pivotally connected to an arm I3 of a bell crank lever which is pivotally mounted at l4 to a suitable support I5. An arm I6 of the bell crank lever is connected to a relatively stiff control rod II which in turn is pivotally connected to what I term a supervisory lever l8 pivotally connected at I9 to a support arm 20 preferably made integral with the mechanical governor 8. The lever l8 has an arm 2| normally held in contact with a plunger 22 by an adjustable spring 23. The plunger 22 has its inner end 24 formed as a seat for the end of a spring 25, the opposite end of which engages a seat on the lever 1.

In the operation of this construction, and assuming that the engine is running at its top speed as controlled by the main lever I of the mechanical governor 8, when the load comes onto the engine through the use of the generator, the tendency of the engine is to drop in speed, which acts to move the lever I to the right, which will tend to close the throttle 4. However, the current from the generator G instantly energizes the electro -magnet H, moving the core or movable member 52 inwardly, and this will move the rod IT to the ri ht, causing the lever l8 to move its end 2i, in opposition to the spring 23, away from the spring 25, thereby relieving the tension on the spring which has heretofore been compressed from both ends as has been explained, thereby allowing the lever I to move to the left, or tending to open the throttle, or to at least hold the throttle so that the engine will continue at its top running speed. A release of the load on the generator will work the apparatus in reverse direction.

In Figure 2, the same type of mechanical governor is shown as in Figure 1, but the hookup, while in reverse direction, functions the same as for Figure 1, with the one exception that I have shown two electro-magnets II and 26one, II, to operate from the D. C. side of the-generator, and the other, 26, to operate from the A. C, side of the generator, as in some cases the generators, for certain purposes, are made to deliver both A. C. and D. C. current. As shown in Figure 2, the movable member 21 of the electro-magnet 26 is connected in series or directly to the member l2 of the electro-magnet H so that either one can operate independently of the other, or both may function simultaneously, and the electromagnets will deliver their pull on the respective movable members in proportion to the load on the respective parts of the generator.

In Figure 3 the mechanical governor 28 is somewhat diiTerently constructed from the governor 8 shown in Figure 1, in that the main lever 29 has an arm 3D connected through a spring 38 to a pivotal lever 32 having an adjustment to regulate the tension of the spring 3|. The arm 28 is connected through a joint 34 something on the order of a ball-and-socket joint, and rod 35 to a lever 36 connected to the engine throttle 4. The opposite end of the lever 36 is connected through a rod 31 to the movable member 12 of the electro-magnet II, In this arrangement, the operation of the governor 28 moves the lever 29 to the right as the engine speed increases up to the stop point. This moves the throttle 4 toward the open position and likewise moves the plunger or movable member I2 of the electro-magnet ll toward the position where the eilect of the electro-magnetic field will act on it very quickly, so that as the load comes on the pull on the member 12 acts to open the throttle 4 against the opposite action of the mechanical governor and the spring 3|.

Where the output of the generator is not too great, I prefer to pass all the current from the generator through the electro-magnet or electromagnets, but in those cases where the output in the set is too large to make this practical, I may run only a part of the current, if D. 0., through the electro-magnet II and use a series transformer in the A. 0, output side of the generator, the secondary of the current transformer being taken to the electro-magnet 26. I have found that the current control as herein explained is more satisfactory for all-around purposes than voltage control or a combination of voltage and current control.

In Figure 4 I have illustrated, diagrammatb cally, a hookup in which the engine drives a plurality of generators; one, a D. 0, generator connected to a magnet 38 through the leads G-l and either a multi-phase generator having two of its phases connected to the electro-magnets 39 and 40 through the leads G2 and G--3, or two A. C. generators connected to the electromagnets 39 and 40. The movable core member 4| of the electro-magnet 38 is pivotally connected to a yoke 42. A movable core member 43 of the electro-magnet 40 is connected by the rod 44 to the movable core member 45 of the electromagnet 39. The movable core member 45 is pivotally connected to the yoke 42. The connection ll between the mechanical governor lever l8 and the yoke 42 may be shifted to any one of the connecting points 46, 41, 48 and 49 on the yoke 42 in order to get a proper working balance between the electro-magnets 39 and 40 on the one side, and the D. C. electromagnet 38 on the other side, whereby a satisfactory pull may be applied to the governor lever l8.

It will be obvious that certain details for applying my invention to practice will vary according to the engine and mechanical governor used and the requirements of the generator output.

What I claim is: I

l. A supervisory control means for an engine mechanical speed governor having a main lever operatively connected to the engine throttle, said means comprising an electro-magnet having a winding responsive to the load of a generator driven by the engine, a supervisory lever mounted on the mechanical governor and having one end inter-connected to said main lever through the medium of a spring, the electro-magnet having a movable member connected to the other end of said supervisory lever whereby current from the generator passing in said winding acts through said movable member and supervisory lever to at least balance out the action of the mechanical governor which allows the engine to slow down as the load comes on.

2. A supervisory control means for an engine mechanical speed governor having a main lever operatively connected to the engine throttle, said means comprising an electro-magnet having a winding responsive to the load of a generator driven by the engine, a supervisory lever mounted on the mechanical governor and having one end inter-connected to said main lever through the medium of a spring, means acting on the supervisory lever serving in conjunction with the main lever to compress said spring when the engine is running light or under light load, the electro-magnet having a movable member connected to the other end of said supervisory lever whereby current from the generator passing in said winding acts through said movable member and supervisory lever to reduce the compression on said spring and allows the main throttle lever to open under load.

3. In an internal combustion engine-generator set having, a mechanical governor operatively connected to the engine throttle through the medium of a lever carried by the governor, means for applying to the mechanical governor lever a supervisory control to prevent variations in speed of the set, said means including an electro-magnet having a movable member being interlinked with said governer lever so as to instantly move the same as the load changes to hold the speed constant, and spring means comprising part of the interlinking and acted on by both the mechanical governor and the electro-magnet.

4. In an internal combustion engine generator set having a mechanical governor operatively connected to the engine throttle to limit the maximum speed of the set, and the generator being of the type which will deliver both alternating and direct current; means for applying to the mechanical governor a supervisory control to hold the speed of the set constant, and thereby the voltage and frequency of the generator, said means comprising a separate electro-magnet for each type of current, and each magnet having a movable member connectedto move as one and interconnected with the mechanical governor and engine throttle to control the action thereof, the electro-magnets being substantially instantly responsive to variation in generator load, thereby acting on the engine throttle to prevent a change in speed.

5. In an internal combustion engine generator set having a mechanical governor operatively connected to the engine throttle to limit the maximum speed of the set, and the generator being of the type which will deliver both alternating and direct current; means for applying to the mechanical governor a supervisory control to hold the speed of the set constant, and thereby the voltage and frequency of the generator, said means comprising a separate electro-magnet for each type of current while their movable members are interconnected to the engine throttle so at least the movable member of the electro-magnet being excited will act on the engine throttle to control the action thereof.

6. In an internal combustion engine-generator set having, a mechanical governor operatively connected to the engine throttle and having the characteristic of mechanical governors of allowing the engine speed to change before the governor can act, means for overcoming the action and, if desired, actually raise the speed above that fixed by the mechanical governor, said means including an electro-magnet responsive to current from the generator and having a movable member inter-connected with the mechanical governor and the engine throttle and acting thereon to move the throttle to give the desired speed and at least one control spring serving as part of the interconnected overcoming means.

7. In an internal combustion engine-generator set having a plurality of generators, one of which is of the D. C. type, operatively connected to the engine which has a mechanical governor connected with the engine throttle to limit the maximum speed of the set; means for applying a supervisory control to the throttle over the mechanical governor for the purpose described, said means including an electro-magnet connected to the D. C. generator and an electromagnet connected to each of the A. C. generators or each phase thereof, a yoke connected to the mechanical governor, the connection being adjustable along the yoke, the movable members of the A. C. electro-magnet and the movable member of the D. C. electro-magnet being connected to opposite ends of the yoke.

8. In an internal combustion engine-generator set having a plurality of generators, one of which is of the D. C. type, operatively connected to the engine which has a mechanical governor connected with the engine throttle to limit the maximum speed of the set; means for applying a supervisory control to the throttle over the mechanical governor for the purpose described, said means including an electro-magnet connected to the D. C. generator and an electro-magnet connected to each of the A. C. generators or each phase thereof, and means for adjustably connecting the movable members of said electromagnets together and to the mechanical governor.

9. Supervisory control means for an engine mechanical speed governor having a main lever operatively connected to the engine throttle, said means comprising at least one electro-magnet having a winding responsive to the load of a generator driven by the engine, a supervisory lever mounted so as to have one end interconnected to said main lever through the medium of a sufilciently resilient device, an electro-magnet having a movable member connected to the other end of said supervisory lever whereby current from the generator passing in said winding, acts through said movable member of the supervisory lever to produce a reverse action of the mechanical governor which allows the engine to slow down as the load comes on.

CLAUDE J. HOLSLAG.

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