US323470A - Cut-out for dynamo-electric machines - Google Patents

Description

(No Model.) -2 Sheets-Sheet 1.

0. J. VAN DEPOELE.

' GUT-OUT FOR DYNAMO ELECTRIC MACHINES.

No. 323,470. Patented Aug. 4, 1885.

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(No Model.) 2 SheetsSheet 2. G. J. VAN DEPOELE.

GUT-OUT FOR DYNAMO ELECTRIC MACHINES.

No. 323,470. Patented Aug. 4, 1885.

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UNITED STATES PATENT OFFICE.

CHARLES J. VAN DEPOELE, OF CHICAGO, ILLINOIS.

CUT-OUT FOR DYNAMO- ELECTRlC MACHINES.

SPECIFICATION forming part of Letters Patent No. 323,470, dated August 4, 1885.

Application filed November 15, 1884.

To all whom it may concern:

Be it known that I, CHARLES J. VAN DE- POLE, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Cut-Outs for Dynamo-Electric Machines, of which the following is aspecification, referencebeing had to the accompanying drawings.

The present invention relates to devices forming part of an ordinary electric lighting circuit, and operating to prevent damage to the generator in the event of the breakage of the consumption-circuit, more especially when the field-magnetsof the generator are supplied with current from a source not directly dedendent upon or connected to the consumption-circuit.

In the accompanying drawings, Figure 1 is adiagrammatic view of apparatus arranged to illustrate my invention, the generator and switch-box being represented in elevation.

Fig. 2 is a theoretic diagram of the circuits and connections. Figs. 3 and 4 are views similar to Figs. l and 2, except that they illustrate my invention as applied to a shuntmachine, instead of to one having a compound armature.

Similar letters indicate like parts.

A represents a dynamoelectric machine the armature of which is wound with two sepa rate sets of coils, each set being represented by a commutator and pair of brushes, substantiall y as set forth in Letters Patent No. 297, S78,

granted to me April 29, 1884. B is a box containing apparatus as follows At its lower portion is an electro-magnet, C, directly above which is arranged a pivoted lever, D, the free end of which lever extends beyond the end of the magnet and projects through a slot in the side of the box, as indicated at (1. Above the lever D, at the upper end of the box, is an indicator, E, from the lower portion of which, or some other equally convenient point, extends an adjustable tension device, 6, and spiral spring 6, which latter is attached to the lever D.

The indicator E is not specifically herein described or claimed, as it will form subjectmatter for a separate application intended to be filed by me.

Between the lever D and the indicator are located a pair of contact-bars, F G, which should be in the upward path of the lever D,

(No model.)

The upper one is preferably fixed in a horizont-al position,while the lower one, G, is pivoted so as to be capable of free upward movement. A suitable pin or stop, g, supports the lower contactbar in any desired position between the upper bar, F, and the lever D,which latter, being wholly or partly of iron, will be held down by its magnet when the line is in operation at a point below the lower contactbar.

The consumption-circuit passes from the armatn re coils, set apart for that purpose, through the commutator H, brushes h h, and binding-posts J J. From J it passes by conductor K to and into the box B,where its coils pass around the indicator, from whence they are continued to the electro-magnet C, leaving which and issuing from the box through suitable binding-post the said conductor is carried to the lamps L or other working resist ances in circuit and back through bindingpost J and brush h to the armature of the generator.

The end pieces of the magnet C are of iron; but they may be of diamagnetic material, and the ends of the core be continued to their circumference with either construction. \Vhen the main current is passing in the coils ofthe magnet, the lever D, it within its magnetic 'field, will be attracted and firmly held in its lowest position against the poles of the said magnet.

It will thus be seen that the consumptioncircuit passes through the box B, but is not broken or in any way altered by the action of the apparatus therein contained, the safetycircuit being a separate and distinct one, as follows: The remaining coils of the armaturethose not feeding the consumption-circuit are represented by a second and usually smaller commutator, upon which bear brushes M M, from which lead two circuits, one including the iicldmagnet coils only, and a second represented by the conductors N O, which pass directly to the box B and through suitable binding posts to the contact bars F G, which, as stated, are so disposed that when the lever D is depressed they are separated, and the branch circuit, which, when closed, forms a short circuit around the field coils, is broken.

The operation of the device is as follows:

At starting the armature is put in motion, but no current is produced, because the spring e holds up the lever D, bringing the contacts G and F together and short circuiting the field-magnets across the second set of commutator-brushes; but when the lever D is depressed and held down for a moment the contacts separate, opening the branch circuit, when current is immediately produced in both divisions of the armature, one portion passing to the field-coils and the other energizing the magnet O with sufficient force to hold down the lever D, which, being so held as long as the current flows uninterruptedly, stands ready when released by the demagnetization of G to be carried upward by the spring 0 sufficiently far to bring the contacts F G together, and by so short -circuiting the fieldmagnets to instantly stop the production of current and prevent injury to the apparatus.

As shown in the annexed drawings, the safety-switch is applied to a dynamo having a second commutator and separate armatureeoils intended to energize the field-magnets of the dynamo while the first commutator and the main armature coils are used exclusively to operate the working-circuit; but I do not limit myself to this special class of generator, since the device may be equally well applied to a shunt-dynamo by connecting the safetycircuit to the main binding-posts, as shown in Figs. 3 and 4. In this case, also, as soon as the main circuit is broken the contacts will come together and short-circuit the field-magnet coils, thus stopping the production of current and saving the machine harmless.

In practice, and especially with large dynamos, I find it absolutely necessary to use the cut-out, for, in case that the main circuit opens and the magnetism of the fieldmagnet is maintained, the current which before the opening was quietly flowing along the line and workingcircuit, will now pass around the commutator from brush to brush, and in a few seconds the armature may be permanently disabled. However, by means of the safetyswitch, the very instant the main circuit breaks the field-magnet coils of the dynamo are deprived of their current, which stops the production of current in the armature-coils, thus saving the latter harmless. Let it be remembered that in case of breaking of the main circuit of a series dynamo the current production will be stopped by the opening of the circuit, the machine being in the main circuit, which is not the case with a doublearmature machine or with a shunt-wound dynamo.

I claim 1. In a system of electric lighting, a dynamo-electric generator having an armature with two independent circuitsone the main and the other the field-circuitand a bypass or circuit of low resistance around the field-magnets, said by-pass being normally open while the machine is in operation, in combination with an electro-magnet in the main circuit. said magnet being adapted on the breaking of said main circuit to close the by-pass circuit, thereby diverting the current from the fieldmagnets in order to stop the production of current in the armature-coils on the breakage or interruption of the main circuit, as described and set forth.

2. In a system of electric lighting in which the field-circuit of the dynamo or generator is supplied by an independent current from its armature or by a shunt from the same, an electro-magnet in the main circuit operating a short-circuiting device whenever the main circuit is interrupted or broken, said shortcircuiting device shunting through a low resistance the current supplied to the field-magnets in order to deprive the latter of their magnetism, and thus to stop the production of current in the machine.

3. In a system of electric lighting wherein the field-magnets of the dynamo are excited by a derivation from the main current, an automatic circuit-closer, and means, substantially as described, for holding down, as long asthe working-circuit is closed, a contactbar putting the field-coils of the dynamo in operative condition, and for short-circuiting the field-circuit whenever the main circuit is broken or interrupted, for the purpose set forth.

In testimony whereof I affix my signature in presence of two witnesses.

CHARLES J. VAN DEPOELE.

\Vitnesses:

THEO. P. BAILEY, \V. S. STEARNS.

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