US316500A - Half to the grand eapids electric light and power - Google Patents

Description

(No Model.) 3 SheetsSheet 1.

- W.- M. THOMAS.

GOVERNOR POR- ELEGTRIU MOTORS, 8w.

Patented Apr. 28, 1885.

WITNESSES I INVENTOR WilliamM. Thomas By hi3 l/lttorneys flaedmfil a Lithopnphnr, Wnbmgiun. n c

N PETERS Pbetu- 3 S A M O H T M GOVERNOR FOR ELECTRIC MOTORS, 61:0.

Patented Apra 28, 1885. Fig. 2.

INVENTOR Wllium fiZT/wmas By his Jifforneys x x Mun 09% 91/,

' WITNESSES S w ca. 0. M

3 S M 0 H T M GOVERNOR FOR ELEGTRIU MOTORS, &0.

Patented Aprn 28, 1885.

I INVENTOR mm'fif 2%0271641' By 723.) ui'ttorneys UNITED STATES PATENT OFFICE.

WILLIAM M. THOMAS, OF GRAND RAPIDS, MICHIGAN, ASSIGNOR OF ONE- HALF TO THE GRAND RAPIDS ELECTRIC LIGHT AND POXVER COMPANY,

OF SAME PLACE.

REC MOTORS SPECIFICATION forming of Letters Patent No. 316,500, April 28, 1885.

(No model.)

To all whom it may concern:

Be it known that I, WILLIAM M. Tnorms. of Grand Rapids, in the county of Kent and State of Michigan, have invented certain new and useful Improvements in Governors for Electric Motors and other Machines, of which the following is a specification.

The object of my invention is to provide a simple, accurate, and adjustable device for governing the speed of electric motors and other machines which are controlled by electric devices; and the invention consists in the employment of a vibrator actuated by the ma chine to be governed, as is fully set forth below.

In the accompanying drawings, Figures 1, 2, and 3 are diagram views illustrating several different applications of my improvement, and Fig. 4 is a view illustrating one way of adjusting the controlling-vibrator.

All vibrators possess a certain definite or fundamental rate of vibration, and are slow to respond to vibrating impulses which do not coincide with their normal rate. "When impulses tending to vibrate a body are imparted to it at the same rate as its normal rate of vibration, or approximately so, the body will vibrate freely and with increased amplitude. Imake use of this principle in governing electric motors, and I control them by means of a vibrator which is actuated by means of the armaturespindle, or some moving part of the machine, as is fully described below.

In Fig. l I have illustrated diagrammatically and as simply as possible an electric motor in which the field-magnet coils and armaturecoils are included in separate branches of the main circuit.

To illustrate my invention I have shown the end of the motor-spindle A as flattened or cut away on two opposite sides. A vibrating arm or bar, B, which is secured in asuitable post, B, and may be adjusted therein by a set-screw, b, is placed, as illustrated in the drawings, so as to bear upon the armature-spindle at the point where it is reduced or flattened at the sides. The circuit in which-the field-magnets are placed is indicated by the full arrow, while the branch in which the armature-coils are included is indicated by the dotted arrow, and

runs from the main line to the post B, in which the vibrating arm B is mounted,through the arm, to the spindle of the armature, or an insulated collar on the spindle, thence to the positive brush of the machine through the armature-coils,to the negative brush,and then 5 5 to the main line again. When the motor is started into operation, portions of the spindle a which are not reduced or cut away will strike the vibrator B as the spindle rotates. As the vibrator is very sluggish in responding to any vibrating impulses other than those which are equal, or approximately equal, to its normal rate of vibration, it will continue in contact with the spindle as the spindle rotates until a speed hasbeen attained at which the strokes of the portions to upon the vibrator equal, or approximately equal, the normal rate of vibration of the vibrator B. hen this speed has been attained, the vibrator, in response to such impulses, will vibrate with greater amplitude and ily out of contact momentarily with the spindle. This opens the branch circuit (indicated by the dotted arrow) in which the illlllittlllG-COllS are included, and of course slows the motor. The moment at which the vibrator will break contact with the spindle will be when one of the sides a of the spindle throws the vibrator away from the spindle. The point at which the interruptions in the circuit occur can therefore be regulated by placing the vibrator in varying tangential lines relatively to the spindle,'so that the moment of break may be made to occur when the armature is in its most efiective position. A suitable arrangement for this purpose is illus trated in Fig. 4., in which the postB, carrying the vibrator, is indicated as adj ustably mounted in a slotted frame, the slot being in the arc of a circle of which the motor-shaft is the center.

The figure illustrates, and I have described, 0 the opening by the governor of the branch in which the armature-coils are included. Of course, however, it is entirely obvious that the branch in which the field-magnet coils are included might be opened and the armature 5 branch remain permanently closed, or that the main line might be opened entirelywhere the armaturecoils and field-magnet coils are in series in the circuit. The latter arrangement, however, will only answer where there is but one motor in the circuit, or where motors are connected in multiple are. \Vhere several motors are included in the same circuit, either the armature branch of the circuit or the fieldlnagnet branch might be controlled at each motor, as described, without interrupting the continuity of the circuit. \Vhere motors are connected in series, however, I prefer to use some such arrangement as is illustrated in Fig. 2. In that case the vibrator B, in its movement away from the armattire-spindle, may make contact with a spring-arm, D, which carries an adjustable contact, d, so as to close a supplemental circuit, 8, around the armaturecoils. Another good series arrangement is shown in Fig. 3, where the movement of the vibratorB out of contact with the spindle may compel the current to pass through a branch c rcuit, 1, containing a resistance, B, into the circuit of the armature-coils.

This governor is equally applicable to the control of dynamo-electric generators or other electrically controlled machines of various characters, as it is obvious that the movement ofthe vibrator may be utilized in various ways, and I do not therefore confine myself to the particular organizations described or illustrated.

Instead of two points which act upon the vibrator, one only, or more than two, may of course be used, and it is entirely immaterial as to how they are arranged.

The "fundamental rate of vibration of the governing vibrator may readily be obtained by a test in any ordinary way. and the vibrator so adjusted to the machine that it will act to control the machine when it reaches the maximum speed desired.

I claim as my invention- 1. The combination of an electric motor or other electrically-controlled machine and a vibrating governor actuated by the machinev said governor having a normal rate of vibra tion and serving to check the speed of the machine when the amplitude of vibration is abnormally increased, as set forth.

2. The combination of an electric motor or other electricallycontrollcd machine, a vibrating governor actuated by said machine, said governor having a normal rate of vibration and serving to check the speed of the machine when the amplitude of vibration is abnormally increased, and an electric circuit which governs the speed of the machine and is controlled by the vibrator.

3. The combination of an electric motor or generator, an electric circuit in which said machine is placed, and a vibrating governor actuated by the machine, having a normal rate of vibration and serving to check the speed of the machine when the amplitude of vibration is abnormally increased, by which the conditions of thecircuit or branches of the eircuitthrough the machine are controlled.

4. The combination, substantially as set forth, of an electric motor or generator, an electric circuit in which it is included, a vi brating governor actuated by the machine, having a normal rate of vibration and serving to check the speed of the machine when the amplitude of vibration is abnormally increased, the armature or field-magnet circuit in which said vibrator is included, a supple mentary branch circuit thrown around said armature or field-magnet circuit,and contacts by which said supplementary circuit is completed by the vibrating governor when the speed of the motor has reached a given point.

In testimony whereof I have hereunto subscribed my name.

M. THOMAS. Witnesses:

J. W. SrooNnn, WM. H. Pownns.

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