USRE8102E - Improvement in dynamo-electric machines - Google Patents

Description

E W E S T 0 N Asgignor of one-half interest to Roberts & Havell.

DYNAMO ELECTRIC MACHINE. No. 3,102.

Reissued Feb. 26,1878.

. INVE TOR 6440M ATTORNEYS WTTNESSES UNITED STATES PATENTOF-FIGE.

EDWARD WESTON, 0F NEWARK, NEW JERSEY, nsslcson or ONE-HALF INTEREST TO ROBERTS & HAVELL, 0F snmn PLACE.

IMPROVEMENT IN DYNAM'OY-ELQECTRIC MACHINES.

Specification forming part of Letters Patent No. 182,977, dated October 3, 1876; Reissue No. 8, 102, dated February 26, 1873; application filed June 6, 1877.

To all whom it may concern:

. Be it known that I, EDWABD' WEsTON, of Newark, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Dynamo-Electric Maence marked tliereomwhich form a partof this specification.- I

Inelectroplating by means of a current generated in a dynamo-electric machine, the directi'on of the current is liable to reversal when the rotation of the machineis arrested or considerably diminished in speed, because, under such circumstances, a return current flows from the electrodes through the machine, and reverses the polarities of the electro-magnets. If the motion of the machine be thenrcsumed, the current generated flows in the reversed disection, and removes from objects remaining in' the platingsolution the metal'which has been deposited upon them by the action of the original current. Thus the work done by a current flowing in one direction is undone by a current permitted to flow in the opposite di-' rection. It'will, hence, be seen that it is of great importance to insure persistcncy in the direction of the current generated by a dynamo-electric machine employed in electroplating or electrotyping. To secure this resalt is the primary object of my improvement; and to that end my invention consists in the combination, with a dynamo-electric machine and an electroplating-vat, of an adjustable switch, which automatically closes the circuit between the machine and the vat when the chine, automatically breaks the circuitof which I the electroplating vat forms a part, or, ac cording to the mode in which it is arranged to o te, provides a path to a short circuit, 11 which the curmntsfrom the electrodes 'rou:

may ow until exhausted.

My invention also includes a switch of poculiar construction, adapted to the purpose iu thrown and maintained in or out 01' the circuit, as the case may be, either by the preponderating action upon it of centrifugal force as against the force of gravity, or vice versa, the preponderance of either force being dependent upon and governed by the speed of rotation of the dynamo-electric machine.with which the switch is combined. I

Finally, my switch s adjustable, so that it can be arranged to perform its function atany given rate of speed of the dynamo-electric machine.

My invention therefore is to be considered in a twofold aspectfirst, as exhibiting the combination of a dynamoelectric machine and an elwtroplating-vat with an automatic switch, acting concurrently with a given diminution in the strength of the current generated by the dynamo-electric machine, to pre- .vent the reverse current" from the electrodes in the vat from passing through the coils of the electro-rnagnets in the machine, andthereby reversing their polarities; and, secondly,

' In the accompanying drawings I have dee mod it necessary toshow'only my improved switch, as both dynamo-electric machines and elective plating-vats are well known and in com mon use.

The drawings areas follows: Figure 1 is an elevation of my apparatus, showing the upper portion of it in central vertical sect-ion. Fig. 2 is a top view of a detached part of the apparaum y The structure shown in the drawings consists of a vertical pillar, A,-of brass, iron, or other conducting material, terminating at the top in a steel pin, B, which serves as the vertical axis or pivot upon which the cup 0 rotates. On

the machine are connected with this ap the bottom of the cup is astem or huh, D,recessed to admit the pin B, and provided with the pulley E, for the reception of a drivingbelt leading from the shaft of a dynamo-electric machine, or from anyother source of motion. The interior of the'low'er part ofthe 'cup is provided with the radially-arranged ribs or paddles a a, as shown in Fig. 2. A short distance from thepillar A is another, pillar, G,

the upper endof which is bent at or about a right angle, so as to prtgect a little way over the center of the cup as show'nin Fig. 1-. A hole is drilled near the end'of this pillar, in a line with the axis of the cup '6, to receive thevertically-adjustable wire b, which is held in positionby means of the setscrew d. The pillars A and G may be fastencdin any suitable manner to a piece of-wood or any other,

insulating material, or to the base of the machine. The wire b is cleaned and amalgamated with mercury, and a small'quantit'y of the inner surface of the cup, and hence the connection between the wire and. the cup will be broken.

Supposing, now, that the two, wires H from para- .tus,'one wire to each pillar, and the machine started, the current willfl ow up the pillar A,

through the mercury, up the wire b, and down the pillar G to the other wire, and back again to the machine, thus completing the circuit. Under'these conditions, what may be called the short loop of the circuit is closed; but if the cup 0, containing the mercury, be caused to rotate by means of a belt running from the shaft of the machine, then it is obvious that y when themachine, and consequently the cup, has reached a certain speed, the connection will be broken, thus opening the short circuit or shortloop. If there is an outside conductor connected to the two pillars, the current, being no longer able to flow through the short 100 of the circui will be diverted into and can ow through t e external conductor, which may be called the long loop" of the circuit.- (ion.- versely, when the machine, and consequent- .ly the cup 0, falls to a certain speed, the connection between the cup and wire b will again becompleted, and the'current will cease toflow into the external conductor. If the external {circuit includes an electroplatingwat, the reverse current fromthe vat, instead of flowing through the coils of theelectro-magnets, is at forded a short circuit through the mercury, and,.flow-ing' through that, vwill soon be exhausted.

By a slight modification this apparatusinay be made to close the circuit between the vets and the machine when the machine reaches a certain speed, and break it again when it falls below that speed. I prefer to do this in the case of large machines, which, when they are on closed circuit with small resistance, require considerable power to start them, and

"there is great danger of the belt running oif before they reach thespeed necessary to open the circuit and break the connection by the mercury rising and leaving the wire b. In

this case it is necessary to use alwire with a disk of metal slightly smaller than the. largest part of. the inside of the cup 0, so that when the cup revolves and the mercury rises it will touch the disk, and when it falls again the connection will be broken.

In order to use this arrangement it is necessary to connect one of the wires proceedin g from the machine .to one of the pillars, and. the other pillar is to be connected to a binding-post, to which a wire-leading from one ofthe electrodes of a vat may be attached. The

other wire from the machine is connected directly to the other electrode in the vat, or, more conveniently, to a binding-post on the base of the machine, to which a Wire may be attached at any time. With this arrangement the circuit between the machine and vat is not,

closed until the machine reaches a certain speed, which can be varied by raising or lowering the disk, and the connection is again of a massor'masses of metal, may be madeto answer the same purpose. For instance, the mercury may befdispensed with, and a small governor, similar to those which are '.used for steam-engines, may be used. The

balls expanding and contracting at various speeds, may be made-t0 open or close the em cuit in various ways. 7

By a slight modification this or a similar arrangement may be directly attached to the shaft of the machine, instead of using a belt or other mode of transmitting the power.

It has heretofore been attempted to divert,

a current of electricity generated in a dynamoelectric'machinei'rom one circuit into another-- as, for example, from a short circuit or short loop of a circuit into a long circuit or long loop of a circuit-by means of a movable at mature, capable of forming a link or section of either circuit, and held in the short circuit by a spring or weight until withdrawn therefrom and placed in? electrical connection with the long loop by the attraction of an electro-magnet excited by the current from the machine.

:This contrivance, which was designed to eflect the simultaneous ignition of a-nun ber offuses, does not produce the efiect of a switch inobliterating one path and permanently holding open another path, because, so soon I as the armature forms an electrical connection with the longer circuit, the tension-of the current, owing to its diversion into the longer circuit, is diminished, and the power of the elccfro-magnet is consequently so reduced that the magnet ceases to hold thearmature in the long circuit. The armature flies back into the short circuit in obedience to the action of the spring upon it, and remains in the short circuit until the electro-maguet has'again acquired sufiicient power to attract and move it into the longer circuit. The result is a series of vibrations of the armature from one circuit tothe other, producing currents alternately through the short loop and the long loop.

0n the contrary, the function of my switch is to open or close a circuit, as the case ma be,

under given conditions, independently '0 any efi'ect upon the switch itself of the current, which is shunted from one circuit into the other.

In electroplating there is necessarily variability in the resistance of the circuit, accordin g to the variability in the number of objects v suspended in the plating solution.

It will be seen that my invention performs its function without being affected by any variability in the strength of the current resultin g from variability in the resistance of the crcuit, because the power which operates my switch is derived from the mechanical force which operates the dynamo-electric machine.

I claim as my invention- 1.For use in combination with a dynamoelectric machine, a mechanical switch operated by a mechanical connection withthe ma chine, or with the driving-power thereof, for automatically opening or, closing an external electric circuit, and holding such circuit openor closed, according to the speed of the machine, substantially as described. 2. A dynamo-electric machineand an electroplating orelectrotyping vat, respectively included in the same electric circuit, in combination with a short circuit, provided with an auto= v matic switch, adapted toclose the short circuit concurrently with any given diminution in the strength of the current resulting from a diminution in the speed of rotation of the dynamoelectric machine, for the purpose of providing a path through which the reverse current from the electrodes in the vat may flow withou flowing through the machine.

3. A section of an electric circuit, composed of arotating mass of fluid, adapted to occupy difierent positions in or out of the circuit, when subjected in the one case to the preponderatiu-g influence of gravity, or, in the other case, to the preponderating influences of the centrifugal forces generated by its own rotation. v

4. In combination with a magneto-electric machine, a switch operated or controlled by means'of a belt or other mode of transmitting power from a revolving shaft, and an adjustable wire or other piece of metal, the whole being arranged to open or close a circuit between the machine and an external conductor when the speed .of the machine reaches a certain point.

In testimony that I claim the foregoing have hereuntoset my hand this 2d day of June, 1877. Y EDWARD WESTDN. Witnesses:

FRANK GAL'I, J. O. Sonnonnnn.

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