US801245A

US801245A - Electrical controller.

Info

Publication number: US801245A
Application number: US24758305A
Authority: US
Inventors: Henry D James
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1905-02-27
Filing date: 1905-02-27
Publication date: 1905-10-10
Anticipated expiration: 1922-10-10

Description

No. 801,245. PATENTED OCT. 10, 1905. H. D. JAMES.

ELECTRICAL CONTROLLER.

APPLICATION FILED FEB.27.1905.

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WITNESSES; ENTOR c4244, 6. 6% WM ATTORNEY PATENTBD OCT. 10, 1905. H. D. JAMES.

ELECTRICAL CONTROLLER APPLICATION FILED FEB.27.1905

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WITNE mv NTOR yATTOhNEY No. 801,245. PATENTED OCT. 10, 1905. H. D. JAMES. ELECTRICAL CONTROLLER.

APPLICATION FILED FEB.27. 1905.

3 SHEETS SHEET 3.

glNViTOR M 4 TTORNEY UNITED STATES PATENT OFFICE.

HENRY D. JAMES, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO VEST- INGHOUSE ELECTRIC 8: MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

ELECTRICAL CONTROLLER.

Specification of Letters Patent.

Patented Oct. 10, 1905.

Application filed February 27, 1905- Serial No. 247,583.

To all whom it may concern:

Be it known that I, HENRY D. J AMES, a citizen of the United States, and a resident of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Electrical Controllers, (Case No. 1,351,) of which the following is a specification.

My invention relates to controllers for [O dynamo-electric machines; and it has for its object to provide electrical controllers with means whereby injurious sparking or arcing at the commutators of motors or overloading of the windings thereof may be effectually prevented.

In the operation of shunt and compoundwound variable-speed motors in which the speed variation is effected by the successive application of two or more voltages to the armature-winding and by varying the current in the shunt-winding of the field-magnet, or by either of these expedients alone, it has been found that when changing the armature connections from one voltage to another or when suddenly strengthening the motor-field serious sparking is likely to occur at the commutator-brushes on account of variance between the counter elcctromotive force generated by the motor and the elcctromotive force applied 0 to the armature-winding unless some special regulating device is employed.

My invention provides a simple and efficient means for automatically inserting resistance in the armature-circuit when changes are made 3 5 in the voltage applied to said circuit that is more directly responsive and more reliable than the devices heretofore usually employed.

My invention is illustrated in the accompanying drawings, Figure 1 of which is a view 4 in front elevation of a controller which embodies my invention, the cover being removed. Fig. 2 is a sectional view online II II of Fig. 1, and Fig. 3 is a diagrammatic view of a development of the controller-drum and con tactfingers and the connections thereof with the various circuits.

The controller in connection with which my invention is shown and described comprises all of the parts ordinarily embodied in a con- 5 troller for delivering multiple voltages to the armatures of electric motors and for varying the resistances of field-magnet circuits, such as rotatable drum 1, provided with contactsegments and stationary contact-fingers 2 and operated by means of a handle 3. The shaft 4 of the drum 1 is provided with a cam-wheel 5 of approximately circular form, but having projections 6 and 7 located so as to correspond, respectively, to the off position of the controller and to the transitional period between the high-voltage and low-voltage connections. An arm 8 is secured at one end to a shaft 9 and at its free end is provided with a roller 10, that is adapted to engage the pcriphery of the cam-wheel 5.

The roller 10 is held in engagement with the periphery of the cam-wheel 5 by means of a coil-spring 11, one end of which is secured to the controller-frame 12 and the other end of which is provided with a hook 13, that engages a stud 14 on the free end of the arm 8.

A lever 15 is rigidly attached at one end to the rotatable shaft 9 and at its free end is pivoted to the movable portion 16 of the core of a solenoid 17, that is provided with two

windings

18 and 19. The magnet-winding 18 is connected across the terminals of the armature-winding 20 of a motor 21, and the winding 19 is connected between one terminal of the armature-winding 20 and a contact-finger 22, that is connected to the supply-circuit when the controller occupies any of its operating positions.

Secured to the rotatable shaft 9 is a contactfinger 23, which normally engages drum-segment 24 and is raised to break such engagement only when projection 6 or projection 7 of the cam-wheel 5 engages the roller 10. The spring 11 normally maintains the roller 10 in engagement with the cam-wheel 5 and separates the movable portion 16 from the stationary portion 24* of the core of solenoid 17. The elcctromotive force impressed upon the terminals of the winding 19 is approximately that which exists between the supplyconductors to which the motor is connected. while that impressed upon the terminals of the winding 18 is dependent upon the counter electroniotive force generated by the motor. As the counter elcctromotive force rises more current is caused to traverse the winding 18.

When either of the projections 6 and 7 of the cam-wheel 5 engages the roller 10, the portion 16 of the core of the solenoid 17 is brought into engagement with the portion 24 and is maintained in that position by the winding 19 until the counter electromotive force of the motor has risen to such a value as to cause sufiicient current to traverse the winding 18 to neutralize the magnetizing effeet of the winding 19. The portion 16 of the core is then released, and the roller 10 is again permitted to engage the cam-wheel 5. Since the finger 23 is rigidly attached to the shaft 9, it is moved into and out of engagement With the corresponding drum-segment 24 in unison with the movements of the roller 10.

The operation of my controller may be understood by reference to Fig. 3, from which it is seen that when the controller occupies any of positions a to f, inclusive, and the finger 23 is not in engagement with drum-segment 24, a circuit is established from supply-conductor 25 through contact-finger 26, drum-segment 27, drum-segment 24, finger 22, resistance 28, armature 20, series fieldmagnet winding 29, contact-finger 30, drumsegments 31 and 32, and contact-finger 33 to supply-conductor 34. Distributing-conductors 25, 34, and 35 may be supplied from any suitable source of multivoltages such, for example, as that described in Patent No. 513,006, granted to Michael von Dolivo- Dobrowolsky January 16, 1894. It will be seen that the resistance 28 is thus included in the armature-circuit, and any injurious effects that might arise from a too-sudden application of the supply voltage to the armature-winding or from any other conditions is prevented. If, however, the counter electromotive force of the motor rises to such a degree as to permit energizing of the winding 18 sufficiently to neutralize the magnetizing effect of the Winding 19 upon the movable portion 16 of the core of the solenoid 17, the finger 23 is permitted to engage drumsegment 24, and the resistance 28 is thereby short-circuited. 1f the controller is moved from position f to position 9, the finger 23 is again raised from the drum-segment 24 and the circuit connection of the armature 20 is changed from distributing-conductor 25 to distribnting-conductor 35, the resistance 28 being includedin the armature-circuit until the counter electromotive force has risen to a predetermined value. When the finger 23 is not in engagement with the drum-segment 24, the circuit is from distributing-conductor 35, through contact-finger 37, drum-

segments

38 and 24, contact-finger 22, resistance 28, armature 20, series field-magnet winding 29, contact-finger 30, drum-segments 39 and 40, and contact-finger 33 to distributing-00nductor 34. Hellically-disposed sets of drum-contacts 41 and cooperating contact-fingers 42 are employed for the purpose of varying the amount of resistance 43 that is included in the circuit of the shunt field-magnet Winding 44, and since they constitute no part of my present invention, except in the sense and to the extent that they are parts of a complete controller having the improvement already set forth and hereinafter claimed, 1 deem it unnecessary to present a description thereof.

While the cam-w heel and cooperating levers constitute a positive means for raising the finger 23 from the segment 24 at predetermined positions of the controller-drn m and one which I prefer to employ, this mechanism may be dispensed with provided the magnet-winding 19 be so constructed as to exert a sufiicient magnetic pull upon the core 17 to raise the finger at the desired positions of the controller, the remaining operations being as before described.

While I have shown and described my invention as utilized only when changing from the ofl' to running positions of the con troller and when changing the voltage supplied to the motor-arn'iatu re, it is to be understood that it may be employed, if desired, in connection with single-voltage systems and may be caused to operate between any two desired positions of the controller. It may also be employed in the operation of two or more electric motors which are arranged to be connected in series and parallel when changing from the parallel to the series connection thereof. A plurality of lingers with means for operating them may also be employed, it it is desired to cut the resistance out of the armature-circuit in sections, and thereby increase the delay.

I claim as my invention** 1. The combination with a motor, and a resistance, of means for effecting changes in the potential applied to the armature circuit, means for cutting the resistance into said circuit, automatic means for cutting the resistance out of said circuit, and means for delaying the cutting of said resistance out of the circuit that depends upon the differential magnetizing effects of two magnet-windings one of which is connected between the armatureterminals of the motor.

2. The combination with a motor, and a resistance, of means for effecting variations in the field strength, means for eiiecting changes in the potential applied to the armature-circuit, means for cutting the res' tance into said circuit, automatic means for cutting the resistance out of said circuit, and means fordelaying the cutting of said resistance out of the circuit that depends upon the dil'lerential magnetizing effects of two magnet-windings one of which is connected between the armatureterminals of the motor.

3. The combination with a motor, and a resistance, of means for effecting changes in the potential applied to the armature circuit, means for cutting the resistance into said circuit, automatic means for cutting the resist ance out of said circuit, and means for delaying the cutting of said resistance out of the circuit that depends upon the ditlerential magnetizing effects of two windings one of which is in the circuit derived from the armaturecircuit and the other in a circuit supplied from another source.

4:. The combination with a motor, and a resistance, of means for effecting variations in the field strength, means for effecting changes in the potential applied to the armature-circuit, means for cutting the resistance into said circuit, automatic means for cutting the resistance out of said circuit, and means for delaying the cutting of said resistance out of the circuit that depends upon the differential magnetizing effects of two windings one of which is in the circuit derived from the armaturecircuit and the other in a circuit supplied from another source.

5. The combination with a motor, and a resistance, of means for effecting changes in the potential on the leads of the armature-circuit of the motor, means for cutting the resistance into said circuit, automatic means for cutting the resistance out of said circuit, and means for delaying the cutting of said resistance out of the circuit that is dependent in its operation upon the difference between the electromotive force applied to the armature-circuit and the counter electromotive force of the motor.

6. The combination with a motor, and a resistance, of means for effecting variations in the field strength, means for effecting changes in the potential on the leads of' the armaturecircuit of the motor, means for cutting the resistance into said circuit, automatic means for cutting the resistance out of said circuit, and means for delaying the cutting of' said resistance out of the circuit that is dependent in its operation upon the difference between the electromotive force applied to the armaturecircuit and the counter electromotive force of' the motor.

7. The combination with a motor, and a resistance, of means for effecting changesin the potential applied to the armature-circuit of the motor, means for cutting the resistance into said circuit, means for cutting the resistance out of said circuit, means for preventing the cutting of said resistance out of the circuit and means for neutralizing the effect of said preventive means when the speed of the motor has risen to a predetermined value.

8. The combination with a motor, and a resistance, of means for effecting variations in the field strength, means for effecting changes in the potential applied to the armature-circuit of the motor, means for cutting the resistance into said circuit, means for cutting the resistance out of said circuit, means for preventing the cutting of said resistance out of the circuit and means for neutralizing the effect of said preventive means when the speed of the motor has risen to a predetermined value.

9. The combination with a motor, of means for effecting changes in potential applied to the terminals of the armature-circuit, means for effecting variations in the field strength, automatic means for delaying the increase in potential at the armature-terminals that is dependent in its operation upon the difference between the electromotive force applied to the armature-circuit and the counter electromotive force of the motor.

10. The combination with a motor, of means for effecting changes in potential applied to the terminals of the armature-circuit, automatic means for delaying the increase in potential at the armature-terminals that is dependent in its operation upon the difference between the electromotive force applied to the armature-circuit and the counter electromotive force of the motor.

11. In a switch for dynamo-electric machinery, the combination with a contact-finger, a movable conducting-segment, means for bringing the conducting-segment into position for engagement with the finger, means for moving the finger from the path of the segment, means for returning the finger into engagement with the segment, means for maintaining the finger out of engagement with the segment, and means for neutralizing the effect of the last-named means.

12. The combination with a motor, of a switch comprising a contact-finger, a movable conducting-segment, means for bringing the conducting-segment into position for engagement with the finger, means for moving the finger from the path of the segment, means for returning the finger into engagement with the segment, means for maintaining the finger out of engagement with the segment, and means for neutralizing the last-named means the effect of which is dependent upon the counter electromotive force of the motor.

13. The combination with a motor, of a switch comprising a contact-finger, a movable conducting-segment, means for moving the conducting-segment into position for engagement with the finger, means for moving the finger from the path of the segment, means for returning the finger into engagement with the segment, a magnet for maintaining the finger out of engagement with the segment, and a second magnet that opposes the effect of the first and the strength of the magnetic field of which is dependent upon the counter electromotive force of the motor.

14. The combination with a motor, and a resistance in the armature-circuit, of a contactfinger for cutting the resistance out of' said circuit, a movable conducting-segment, means for bringing the conducting-segment into position for engagement with the finger, means for moving the linger from the path of the segment for inserting the resistance in the armature-circuit, means for returning the finger into engagement with the segment, means for maintaining the finger out of' engagement with the segment, and means for neutralizing the last-named means, the neutralizing efl'eet last-named means that is dependent upon the IO of Which is dependent upon the counter eleecounter eleetromotive force 01 the motor. tromotive force of the motor. In testimony whereof I have hereunto sub- 15. The combination With a motor, and arescribed my name this 25th day of February, sistance in the armature-circuit, of a contact- 1905.

finger, a eondnoting-segment, means for dis- HENRY D. JAMES. engaging the finger from the segment, means Htnesses: for maintaining the finger out of engagement, J. C. MORSE,

and means for neutralizing the efl'eet of the BIRNEY HINEs.