US1362546A - stone - Google Patents

Description

G. B. STONE.

SPEED CONTROLLING SYSTEM.

APPLICATION FILED SEPT. I. 1917.

Patented Dec. 14, 1920.-

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GUY B. STONE, OF DETROIT, MICHIGAN, ASSIGNOR TO REMY ELECTRIC COMPANY, OF ANDERSON, INDIANA, A CORPORATION OF INDIANA.

SPEED-CONTROLLING SYSTEM.

Specification of Letters Patent.

Patented Dec. 14, 1920.

Application filed September 1, 1917. Serial No. 189,298.

To all whom it may concern Be it known that I, GUY l5. SroNn, a citizen of the United States, residing at Detroit county of Wayne, and State of Michigan, have invented certain new and useful Improvements in Speed-Controlling Systems, of which the following is a full, clear, and exact description.

This invention relates to certain new and useful improvements in governing devices for engines and more particularly to governing mechanism for such engines as are used to drive vehicles such automobile trucks or tractors.

On power driven vehicles it has been found frequently desirable to use governors to limit the engine and vehicle speed. Centrifugal governors of various types have frequently been employed. It is an object of the present invent-ion to provide an engine governor capable of control by the operator so that a comparatively wide range of maximum governed speeds can be obtained if desired.

One manner of carrying out this object consists in using for governing a simple supplemental mechanism in connection with a dynamo driven by the engine. Dynamos are commonly used in connection with internal-combustion engines for propelling automotive vehicles, for the generation of start ing, lighting and ignition current. By means of a simple auxiliary mechanism the dynamo may be made to serve as a governor. The wide range of variation of maximum governed engine speeds isobtained by controlling the operation of the generator.

Other objects of the present invention will be pointed out in more detail in the accompanying specification and illustrated in the accompanying drawings.

In the drawings,-

Figure 1 shows diagrammatically one embodiment of my invention.

Fig. 2 shows diagrammatically an embodiment of a modified form of the invention, in which a bucking field dynamo is employed and in which a series resistance is inserted in the main armature circuit for a purpose to be hereinafter explained.

Fig. 3 shows modified circuit connections for the resistance which is in series with the armature circuit.

In more detail in the drawings, 10 represents an internal combustion engine having an intake manifold 11 connected with the usual carburetor, not shown. Within the in take manifold 11 is a throttle 12. The crank shaft of the engine is connected by means of a chain 13, or other suitable driving connections, with the armature shaft 1-1 of a dynamo electric machine. This dynamo electric machine has an armature 15 and the usual field frame 16. Rigidly fastened to the field frame 16 is a frame member 17. As shown in Fig. 1 this frame member 17 is provided with a projecting finger 18, which plays between adjustable stops l9 and 19. As shown in Fig. 2 this finger lS is omitted and a stop is used elsewhere to limit the movement of the field frame. Diametrically opposite from finger 18 is an extension 20 from frame member 17. This extension 20 is pivotally connected with an upwardly extending link 21 which in turn, at its upper end, connects with a. rocking lever 22, which lever is fulcrumed on the top of a cylinder of the internal combustion engine. .iittached to the extreme right-hand end of this lever 22 (Fig. l) is a spring 23 which, at its lower end, is connected with a screw adjustment member 24 cooperating with some fixed frame part of the machine. The opposite end of lever 22 is pivotally con nected with a downwardly extending link 25 which in turn, through hell crank 26, connects with the throttle 12. At the lefthand end of lever 22 there is connected thereto a dash-pot comprising the usual piston which plays in a cylinder containing oil or other suitable fluid. The piston 27 of this dash-pot is provided with a valve 28 which opens when the piston 27 moves downwardly and closes when the piston moves upwardly. It will be apparent that this dashpot device acts in opposition to the spring 23. In other words, the lever 22 has a comparatively free rocking movement in a counterclockwise direction and a retarded movement in a clockwise direction. A supplementary stop 29 is also provided to limit the extreme upward movement of-lever 22.

Electrical connections.

The dynamo electric machine, illustrated in Fig. 1, is of the shunt wound type having a shunt field 30 and adjustable field resistance 31 controlled by field rheostat lever 32. The armature leads 33 and 34 of the machine connect with the storage battery B through the usual reverse current relay R. The load or translating devices are not shown in the drawings, but they are connected to the storage battery in the usual manner.

Operation of the apparatus.

In the dynamo electric machine the reaction between the armature and the field tends to carry the field along in the direc tion of the rotation of the armature. This is usually prevented by means of the base of the dynamo electric machine which rigidly secures the frame to some fixed foundation, for example, the engine crank case. In the present construction this base and the holding down bolts are omitted and the entire dynamo electric machine is supported upon the armature shaft 14. The field frame 16 is therefore free to turn around the shaft 1st as an axis. Since the frame 17 is fixedly connected to the field frame the extent of movement of the field frame will be limited by the contacting of finger 18 and stops 19 and 20. Spring 23 is put under an initial tension by means of the adjustment 24. This initial tension of the spring forces link 2 downwardly and rocks f ame 17 and field frame 16 around in a counterclockwise direction until finger 18 contacts with stop 19 in the position shown in Fig. 1. lVith th s condition of parts the throttle 12 is substantially wide open as shown. Now, as the engine 10 turns the crank shaft in a clockwise direction the armature 15 of the dynamo electric machine will be likewise turned clockwise. Field 16 will tend to follow the armature, but movement of the field around with the armature will be prevented u til the amount of reaction is such that it will ove come the initial tension of spring 23. A fter this occurs any increase in speed of the engine with consequent increase of speed of the armature will cause frame 16 of the dynamo electric machine to move in a clockwise direction. This movement of the field frame will. through extension 20, link 21. lever 9?. link 25 and bell crank 26 turn the. throttle 12 toward closed position and thus will s ow down the engine speed. As the speed of the engine slows down the following tendency of field 16 will diminish in proportion to speed, and when this occurs the spring 23'will again move the linkage so that the throttle will move toward open position and'allow' the engine to speed up to the desired point,

It has been found in practice that it is desirable to dampen this action, and particularly to dampen the return movement of the parts, 2". 6., the movement taking place on the opening of the throttle 12. The dash-pot structure is therefore provided, and this dash-pot slows down the movement of the throttle toward open position but allows the throttle to respond comparatively quickly to the control by the dynamo electric machine when it is moving toward closed position.

lVhen the device is installed on motor vehicles it is desirable to provide some means for changing the speed at which the governor begins to come into action. This may be ei'iected roughly by adjusting the spring by set screw 2st, but the adjustment of speed is referably made by means of the field rheostat 31.

If it is desired to increase the engine speed more resistance 31 is inserted in series with the dynamo field speed by moving the rheostat handle 32 toward the left. This will decrease the field strength and consequently decrease the flux through the generator armature. As this flux is diminished the pull of the armature on the field will be diminished, therefore the spring 23 will hold the throttle open until a higher engine speed is attained than previously. The governing action then takes place and maintains the engine at the desired increased maximum speed. To lower the maximum engine speed the resistance 31 is cut out of the field, as will be readily understood.

By varying the field resistance, the maXimum governed speed of the engine can be made to vary within a relatively wide range of limits. It is desirable, ho'i'e er, to restrict the variation of voltage of the generator within relativelynarrow imits. It has been found possible to accomplish this by consum ing a part of the generator output in a load circuit so as to increase the armature current as rapidly as possible with slight increases in voltage. A storage battery in the load circuit will cause the armature current to buird up rapidly with small increase in voltage since the change in current delivered to the battery is proportional to the change in the difference between generator E. M. F. and battery E. M. F.

t is apparent from the foregoing that if the tension in spring 23 be decreased less torque between the field and armature will be needed to balance the spring. Therefore the spring 23 may be adjusted to vary the limits of maximum speed value between which the engine speed may be caused to vary by the variable resistance 81.

l pon a motor vehicle the rheostat 31 may be located upon the dashboard of the vehicle convenient to the operator, or, if desired, this rheostat may be set to a desired position by those having supervision of the motor vehicle and then locket, so that the maximum speed cannot be changed in any way by the driver of the vehicle.

Refcring to Fig. i, the connections from the rocking frame 17 to the throttle are slightly different. Lever 22 through link 25 connects with a supplementary lever 25 to which the spring 23 is attached. The limit ing stops l9 and 19 cooperate with this supplemental lever 25. This supplemental lever is attached to the piston 27 of the dashpot and also to the bell crank 26, which connects with throttle 12. The dynamo electric machine in this instance is provided with a shunt field 30 having regulating rheostat 31, 32. To assist in inherently regulating the output of the machine a bucking series field 40 is provided. A permanent resistance 41 is inserted in the armature lead 3%, the point or" connection of this resistance being between the connection of the field circuit therewith and the battery. The resistance 41 may be adjustable if desired. The object of this resistance is to absorb a certain amount of the line voltage, and in order for the generator to provide sufiicient voltage to charge the battery it will have to generate a higher voltage in the machine itself. Thus in order to properly charge the battery a greater field strength will be required in the machine and this will make the machine more stable and positive in its action of governing. The increased stability and positiveness is attained since the generator in operating has a greater torque, and this operating torque being higher better overcomes the friction of the bearings and of the linkages which connect with the throttle.

With the construction shown in Fig. 3 the shunt winding 30 is so connected that it receives full battery voltage. WVith the same field winding considerably more resistance would need be cut out of the field rheostat to obtain the same field strength and the same generator voltage. It will also be understood that the stability of the generator may be increased in other equivalent ways. For example, the armature may be provided with a short-circuiting winding, or the armature core may be made solid instead of: laminated. With such a construction eddy currents which are formed in the iron core itself ofier resistance to the rotation of the armature and develop a back torque in the same direction as that formed by the current flowing in the regular armature windin This and other equivalent substitutions may be made by any person skilled in the art.

While I have disclosed my invention in connection with an internal-combustion engine, it is to be understood that the application of my invention is not thus limited, but may be used in connection with other power devices.

It will be understood that my invention is not limited to the precise construction shown and described, or various changes and modifications may be made by those skilled in the art, all coming within the scope of the appended claims.

I claim:

1. In a speed control system, the combination with an engine; of electrical gov erning means including an engine driven generator having a part thereof movable in response to the excitation of the generator and arranged to control the delivery of power medium to the engine; means for controlling the generator field excitation whereby to vary the maximum governed speed of the engine within a relatively wide range of limits; and a load circuit connected to the generator for consuming current therefrom whereby to restrict the range of generator voltage variation to relatively narrow limits.

2. In a speed control system, the combina tion with an engine; of electrical governing means including an engine driven generator having field magnets mounted to move in response to the excitation of the generator and arranged to control the delivery of power medium to the engine; means for controlling the generator field excitation whereby to vary the maximum governed speed of the engine within a relatively wide range of limits; and a load circuit connected. to the generator for consuming current therefrom whereby to restrict the range of generator voltage variation to relatively narrow limits.

3. In a speed control system, the combination with an engine; of electrical governing means including an engine driven generator having a movably mounted field magnet provided with windings, and connected with the engine throttle; a variable resistance connected with the field windings for varying the maximum governed speed of the en gine within a relatively wide range of limits; and a load circuit connected to the generator for consuming current therefrom whereby to restrict the range of generator voltage variations to relatively narrow limits.

4. In a speed control system, the combination with an engine; of electrical governing means including an engine driven generator having a rotatably mounted field magnet provided with windings, and connected with the engine throttle; a variable resistance connected with the field windings for varying the maximum governed speed of the engine within a relatively wide range of limits; and a load circuit connected to the gen erator for consuming current therefrom whereby to restrict the range of generator voltage variation to relatively narrow limits.

5. In a speed control system, the combination with an engine; of electrical governing means including an engine driven generator having a part thereof movable in response to the field excitation of the generator and connected with the engine throttle and tending to close the same as the field excitation increases; a spring tending to open said throttle; means for controlling the generator field excitation whereby to vary the maximum governed speed of the engine within a relatively wide range of limits; a load circuit'connected to the generator for consuming current therefrom whereby to restrict the range of generator voltage variation to relatively narrow limits; and means for varying the initial tension of said springwhereby to vary the limits within which the maximum values of engine speed may be caused to vary.

6. In a speed control system, the combi nation with an engine; of electrical governing means including an engine driven generator having a part thereof movable in response to. the excitation of the generator and arranged to control the delivery of power medium to the engine; means for controlling the generator field excitation whereby to vary the maximum governed speed of the engine within a relatively Wide range of limits; and a load circuit connected to the generator for consuming current therefrom whereby to restrict the range of generator voltage variation to relatively narrow limits; said governing means having adjustable provisions whereby to vary the limits within which the maximum values of engine speed may be caused to vary.

7. In a speed control system, the combination with an engine; of electrical governing means including an engine driven generator having a field magnet movable in re sponse to the torque between the armature and the field, and arranged to control the delivery of power medium to the engine; means for controlling said torque whereby to vary the maximum governed speed of the engine within a relatively wide range of limits; and a load circuit connected to the generator for consuming current therefrom whereby to restrict the range of generator voltage variation to relatively narrow limits.

8. In a speed control system, the combination with an engine; of a spring tending to hold open the throttle of the-engine; an engine driven generator having a field magnet movable in response to the torque between the armature and the field and acting to close said throttle against the action of said spring; means for varying the action of said field magnet against said spring whereby to vary the maximum governed speed of the engine within a relatively wide range of limits; and a load circuit connected to the generator for consuming current therefrom whereby to restrict the range of generator voltage variation to relatively narrow limits.

9. In a speed control system, the combination with an engine; of electrical governing means including an engine drivengenerator having a part thereof movable in response to the excitation of the generator and arranged to control the delivery of power medium to the engine; means for controlling the generator field excitation whereby to vary the maximum governed speed of the engine within a relatively wide range of limits; and a storage battery connected to the generator for consuming current therefrom whereby to restrict the range of generator voltage variation to relatively narrow limits.

10. In a speed control system, the combination with an engine; of a spring tending to hold open the throttle of the engine; an engine driven generator having a field magnet movable in response to the torque between the armature and the field and acting to close said throttle against the action of said spring; means for varying the action of said field magnet against said spring whereby to vary the maximum governed speed of the engine within a relatively wide range of limits; a load circuit connected to the generator for consuming current therefrom whereby to restrict the range of generator voltage variation to relatively narrow limits; and means for adjusting the tension of said spring whereby to vary the limits within which the maximum values of engine speed may be caused to vary.

In. testimony whereof I afiix my signature.

GUY v13. STONE.

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