US336040A - Chaeles - Google Patents

Description

Patented Feb. 9, 1886.

NITED STATES PATENT OFFICE9 CHARLES C. DRAKE, OF TRENTON, NEW JERSEY.

TELEGRAPH AND TELEPHONE PROTECTOR.s

SECIFICATION forming part of Letters Patent No. 336,040, dated February 9, 1886.

Application filed October 24,1883. Serial No. 109,929. (No model.)

have invented certain new and useful Improvements in Protectors for Telephonie and Telegraphic Instruments, of which the following is a specification.

My invention relates to a device adapted to 1o be placed in circuit with telephonic, telegraphic, or other similar instruments, and by means of which they are protected from the injurious or destructive action of electric currents of greater potential or quantity than those with which they are designed to work,

and which normally traverse the circuits in which such instruments are included.

It is a matter of frequent occurrence in locations where conductors convey currents of 2c electricity having a considerable difference of potential or quantity, and where such conduct-ors arc arranged near to one another, that they may become, from various causes, entangled, or a conductor by becoming detached from its support may fall and so cross7 the conductor or conductors of other circuits. Thus, for instance, conductors conveying heavy currents-such as are used for electric lighting systems-may in this manner be brought into 3o contact with the conductors conveying the relatively weak and feeble currents employed with telegraphic or telephonie system, and the latter become media for conveying currents of abnormal intensity or quantity. Static charges may also during atmospheric electrical disturbances acccumulate on the conductors and be discharged with serious effect. Hence it is desirable to arrive at a means for diverting such excessive or abnormal currents 4o from that portion of the main circuit in which the instrument or instruments it is desired to protect are located. At the same time it is also desirable that the instrument or instruments should be not cut out of circuit, but should always be in a condition to perform its or their normal functions irrespective of any excess of current above the normal amount circulating in the main line.

-To attain this object I have devised the 5o herein-described instrument orprotecting device, which consists,essentially,of two electromagnets, one of which has its coil or coils formed from a few turns of coarse wire of low electrical resistance, and the other its coils formed from a number of turns of fine wire of high electrical resistance; or but a single core may be used and the helices of different resistances wound thereon and provided with an armature arranged between an adjustable contact-point over the electro-magnets and an insulated adjustable back stop and adapted to be normally held away from its electromagnet by means of its own weight, or by a retractile spring, which can be so adjusted as to prevent the armature from responding to currents traversing the magnet or magnets not exceeding the ordinary working-current.

The present application relates toa protecting device similar to that described in United States Letters Patent granted to me July 10, 1883, and numbered 280,916, the only difference being that I include a tine-wire magnet, which shall act in conjunction with the coarsewire magnet, and thus render the instrument more sensitivein its action. As before stated, the coils on the electro-magnets are in the main-line circuit, and hence any current which circulates in the main line must necessarily pass through the coils of the magnets. After passing through the magnets the circuit is divided into two parts or paths one of high resistance, within which is included the telegraphic, telephonie, or other instruments to be protected, and the other of low resistance, normally open, but adapted to be closed when the current circulating in the main line imparts sufficient energy to the electro-magnet to enable it to attract its armature. It will be readily understood that the currents in the paths or branches will be in the inverse ratio of their resistances, and hence, if the resistances be properly proportioned, a current which will be sufficient to enable the telegraphic, telephonie, or signaling instruments to perform their normal functions, but not sufficient to injure them, will at all times be transmitted through the instruments, the strength or quantity of the current so transmitted varying with that of the main line,and all excess of current will be diverted through the path of low resistance around the protected instruments to ground or back to the mainline conductor.

In the accompanying drawings,which illus- ICO trate my inventiomsi-milar lettersot--reference indicatelike parts.'

Figure 1 shows a view in perspective of a protector constructed according to my invention. Fig. 2 is a diagrammatic view illustrative of theY different circuits and connections.

In the drawings, Arepresents the main-line conductor, connected to the binding-post B. To the binding-post B, I attach one end of a coarse copper wire, which is wound around' the core of the magnet C to form its coil or coils, ending at the screw E, which passes through and secures the conducting-uprightK to the base of the instrument; Attached` by one end to the screw E is a fine copper wire, which is wound around the core of the magnet O toform itscoil or coils, the'otherrend being carried tofthe binding-post F. I prefer t wind4 the magnet C with but few-convolutions ofA-acoarsecopper wire, whose electrical resistance for any given length shall befeqnaltoY or less-.than that of a similar length of the main-line conductor.

rent; transmitted through the circuit will cause the magnet tobecome'energized and attract the armature.

I do not-limit myselfv to theA particular arrangement ofl the magnets. The; fine. and coarsewire;helicesmaybewound on the same core,. or arranged in relative positionsother than that shown and. described. Locatedv in` front of the magnet, and support'ed'uponI an insulated aXis, l, is the armature D,.the1end etw-hichprojects upward betweenl two setscrews, S` G, arranged in the head offthe uprightK. The set-screwsl are so arranged as: tobegvadjustable, andlto determine` Or'iimittheplay ofthe armature. One of the set.-` screws, G, is provided with av tiprof insulating material, which serves to insulate the arma ture, which is wholly of conducting material,

from the upright K,when the armature rests against .the set-screw, that being its normal` position when uninfluenced bythe magnets. The lower end of the armature, is connected through-the'copper wireYL-with-the binding- 5o post M.

On the end of the instrument,arranged in a line :with the armature, is-asuitablesupport,` O, for the tension-screw P.'

I-Iisa tension-spring, connected at one vendto but insulated from thearmatureD, and at tachedat the other end to the tensioni-screw P..

y Having thus described the invention so far asv relates to. its mechanicaly construction, I

. cuit.

The amount offine wire used upon thefmagnet C shouldbe-sutcient. 25 to=offer a resistanceto the passageoffthe nor-- mal current, so that any slightincrease of cur--A tionwhen included in` the main-line circuity The main-line conductorl A- isconout through, the vbinding-.post QF, andi thence byltl'rev conductor A to'thegbinding-post A2, by the telephone-cord A3 to telephone T, by cord A? to binding-post A5, to return mainline conductor A6. It will be understood that the main-line conductor A A. can bea closed metallic circuit, or the ends ofthe conductors may be connected to ground. The path ofthe current as described isv the path of the normal current, which is sufficient in amount to operate the instruments included in the cir- It isA obvious that the conductors A and A6 can be connected directly to the instrument or'instruments to be protected without the intervention of any cord, such as those at A3 and A. A current of* the amount vdescribedftraversing the normal,l circuit and-.the coil of thefelectro-magnetor magnets :will not impart suiicient energy-toit or them to at-` 85 tract thel'varmature, which is normally held away fromithe magnets bythe tensionof` the" spring H. The tension ofr thisnspringcau be so adjusted as to exertvmorefor less pull upon the armature, and thus providesfa means. of 9o regulating the` amount'ot'current ,which -can betransmittedthroughY the normal circuit. Should any abnormal current be thrown uponv the mai-n line'A, all of such current willv pass: throughfthennagnets C andvG, instantly energizing them, soi asto attract the armature D and overcome the tension of the spring Hand bring the end ofthe armature in contact with the adj ustable-'contact-point Son the :upright K. By making such contact-a path of lowA roo resistanceL-from binding-post B through the magnet-'C to screw E, by conducting upright;- K, screw' S, armature D, wireLto binding;-Y post M,.a nd thence by the conductor W to the;- return main'line'conductorAor to ground-#105 isprovided, and the current will divide andl circulate through the two paths, the amountl oi'- current transmitted through the vseparate paths .being inthe inverse ratio of their ref sistances.- Should any-abnormal current.A be: I io thrownupon the return main-line conductor AQthefpath' of the current will first be through the telephone by vconductor A to the magnets, whieh'will attract the armature as before'and c lose'the path oflow resistance, the1pathoff..r15 the-current then beingdfrom Afby conductor,A W tobinding-post IVI,- wire1L, armature- D, screwS. screw-E, magnet C tor-main conductor A,which'may be connected toy ground. It will bepnoticed' thatw-hen any abnormal current isiizo thrown upon the conductors A or Avandthe: armature attracted, thecurrent dividesjat the' screw E, and the magnet C is included inthe path of highk resistance.`

Irwishitunderstood that I do notlimitmyf' x2 5 self-to thelparticular rmechanical construction ofthe. device-showninfthegdrawingsand de:A scribed ini thef specification, as it isV obvious. that many changes can be madethereinrwithoutdepartin g from'theint'ent of vmy invention. x 3o Iamaware. that-various devices have here;-l toforef-4 been? constructed for.. automatically.

breaking the circuit or for cutting the instruments to be protected out of the circuit; but, so far as I am aware, I am the rst to construct a device which will automatically divert abnormal currents to earth from the main circuit without breaking or otherwise interfering with the circuits in which the instruments to be protected are located; or, in other words, a device located in the main circuit, and through which all the currents circulating on the main circuit pass ,which is inactive and non-responsive to the normal current,but instantly responsive to an abnormal current, whereby the current is split up or divided into two parts and caused to travel two paths of unequal resistance.

I claim as my inventionl. The combination of an electric circuit and electrical instruments included therein, through which a path of high resistance is always maintained, with an automatic electromagnetic device consisting of high and low resistance magnets, and connections constructed to automatically close a path of low resistance around said instruments when the current traversing the main line exceeds the normal amount.

2. The combination of an electric circuit and electrical instruments included therein with a pivoted armature, two electro-magnets, one of high and the other of low resistance, both of which are in the main-line circuit, and

the means controlled by the armature to divert through a path of low resistance around the electrical instruments any excess of current above that normal to the line.

3. The combination of an electric circuit and electrical instruments included therein, through which a path of high resistance is always maintained,with an automatic electromagnetic device consisting ofa magnet having high and low resistance helices, and connections, substantially as described, constructed and connected to automatically close a shuntcircuit of low resistance around the receivinginstrument when the main line is overcharged, and mechanism, substantially as set forth, to retract the armature to its normal position when current in the main line again becomes normal.

4. The combination, with an electric circuit and the electrical instruments included therein, of the means whereby excessive currents are divided and caused to traverse two paths of unequal resistance, consisting of two electro-magnets, one of high and the other of low resistance,a pivoted armature and its connections, and a conductor of low resistance connected to the return main-line conductor, sub stantially as described.

CHARLES C. BRAKE.

\Vitnesses:

JOHN A. STEEN, Lewis W. SCOTT.

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