US433421A - bobbins - Google Patents

Description

(No Model.) 2 Sheets-Sheet 1,

' A. C. ROBBINS.

TELEGRAPHIO CIRCUIT.

No. 433,421. Patented July 29, 1890.

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No. 433,421. Patented July 29, I890.

INVENTOR UNITED STATES PATENT ()FFICE.

ARTHUR c. ROBBINS, or BROOKLYN, ASSIGNOR TO WILLIAM snnnnnws, on NEW YORK, N. Y.

TELEGRAPHIC CIRCUIT.

SPECIFICATION forming part of Letters Patent No. 433,421, dated July 29, 1890.

Application filed April 6 1887. Serial No. 233,935. (No model.)

To all whom, it may concern:

Be it known that I, ARTHUR C. ROBBINS, a citizen of the United States, and a resident of Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Electrical Circuits, of which the following is a specification.

My invention relates to improvements in telegraphic or any electric signal circuits 10 where there are more than two stations, and it is especially adapted to burglar, police, and fire-alarm telegraph and signal systems; and the objects of my improvements are, first, to provide a circuit having way-stations that x 5 shall be always complete, and, second, to furnish such circuit with an automatic grounding device by means of which when a break occurs on the line the circuit is automatically grounded and closed on the faulty side of the nearest station to the break without interfering with the transmitting or receiving instruments at said station. I attain these objects by the apparatus and the connections illustrated in the accompanying drawings, which are made a part of this specification, and in Which- Figure 1 represents two common electroinagnets having soft-iron armatures, grounding-post, resistance coil, and wire connec- 3o tions; Fig. 2, the same with polarized armatures in the electromagnetic fields. Fig. 3 represents common electromagnets having soft-iron plunger-armatures and the wires as connected. One helix is here shown in section. Fig. i is a plan of an electric circuit,

showing two central stations with their instruments, batteries, grounds, and wires, and three way-stations with my grounding apparatus and shunting-circuit. Fig. 5 shows a 40 part of the resistance-coils in rheostatN or N.

Fig. 6 gives a detail View of galvanometer J or J.

Similarletters refer to similar parts throughout the several views.

With a perfect wire a circuit would be formed from the ground at E, Fig. 4, through the batteryB, then through the central station H, relay R, galvanometer J, rheostat N, line L, magnet M, thence through the line 0, re-

. 5o sistance XV, line P, magnet in, and line L to the next station, and in the same manner through stations 2 and 3, through the instruare used for registering signals.

ments of home-station H-viz., rheostat N, galvanometer J, and relay Rto battery B, and thence to the ground at E Thus it is seen that this circuit would be a closed circu t, and the magnets M m in station 1 and M m in station 2 and the corresponding magnets in all the other stations would be magnetized sufficiently, notwithstanding the resistance-coils WV, W, &c., to hold their armatures A, a, A, a, 850., against the magnets and away from the grounded posts G, G (to. If the line were not broken at 00, a current of normal strength starting at earth E would flow from battery B through relay R, galvanometer J, and rheostat N, through line L to station 1, through the magnet M, line 0, the fixed resistance W, magnet on, and similarly through stations 2, 3, and H, through bat- 7o tery B, to earth at E This current is of sufficient strength to magnetize the electromagnets, as M m, at all the stations and hold the armatures, as A a, away from the adjustable points attached to the ground-plates G, G &c.; but it is of insuiiicient strength to attract the armatures of the receiving-instruments R, R, &c., and cause a signal.

Now, if a break occurs in the circuit-as at 00, for instancethe armatures will for an instant be thrown off all the relays; but a complete circuit being immediately formed between E and E the current in this circuit magnetizes all the way-station magnets therein, except an, sufficiently to attract their armatures and lift them oif the grounded posts. A second circuit is alsoformed from E to E Thus two circuits are formed, one from E to E including the home-station H and the waystations 1 and-2, and the other from E to E containing the waystation 3 and home-station H. The currentin these circuits is sufficient to excite the electro-magnets of the grounding apparatus at stations 1, 2, and 3, but insufficient to attract the armatures of 9 5 the relays R and R at the home-stations that The resistances G, C, and 0 inserted in the groundwires of my automatic grounding apparatus, are for the purpose of equalizing resistances I00 and compelling part of the current to fiow through the magnet, thus attracting its armature, and thereby automatically removing the ground after an opening has been repaired.

They also serve, when in use, to more nearly equalize the normal resistance of the line, as they represent electrically the missing electromagnets, as m and M after the break shown at m, Fig. l, has occurred. \Vhen a break in the circuit does occur, asjust described, at a:, all the armatures go to the earth-points; but the divided circuit through D, (Z, D, d, &c., is of nearly equal proportions through the magnets and through the armatures, the resistances at C C, &c.,being of any required amount. The

-current is of sufficient power through the magnets to attract the armatures from the ground-points of all except the right-hand magnet of station 2 and the left-hand magnet of station 3, which magnets are practically dead until the break has been repaired. There can be no Vibration of the armatures, for when once an armature has been attracted to a magnet there is no possible inducement or chance for it to return to the groundingpost as long as a current is kept on the circuit-that is to say, when a break occurs, as at 00, a temporary demagnetization of magnets M m M m and M m takes place and the armatures are all retracted and make connection with the ground, as G G, 850. Then this occurs, a divided circuit is set up at D. One part of the current passes through A, G, and O to E, and the other part through 0 IV P to d, where the current again divides, one part passin through a G O to E, and the other through on L M, dividing at D and going to earth at E The current passing through M is sufficient to attract the armature A, thereby removing its ground connection, after which all of the current passes to d, which division and ground is likewise removed by the magnet m becoming sufficiently magnetized to attract the armature a. Thus one by one the ground-circuits are all removed except those of the armature a and A at stations 2 and 3, respectively. There being no current through their respective electro-magnets on account of the break at as, they are forced to remain against the earth-connections, completing a circuit each way from the break until the same has been repaired, when magnets m and M in their turn will become magnetized and attract their armatures. In order to maintain the normal condition of the circuit from E to E the operator at H compensates by means of the rheostat N for the resistance usually offered by the stations 3 and II. As this resistance is approximately known to him beforehand, he is at once aware of the number of stations missing from his circuit. The attendant 011 duty at H likewise compensates for stations II, 1,

and 2, and is thus informed of the extent of his circuit. The transmitting-keys are normally kept open. I show the key K closed in the shunt-circuit of station 3, by which I cut out the resistance 7 and cause relay R to respond. The current used may be decreased or increased to cause a signal, so long as the minimum current is of sufficient strength to retain the grounding-armatures against their magnets and away from the ground-posts. The keys K and K operate in the same manner as K The relays R and R are adjusted so that they are not affected by the batteries until one of the resistances V, \V, or N is cut out. Should an accidental ground come in at 00, for instance, the galvanometers J and J at stations II and 1-1, respectively, would immediately indicate the length of the circuit from each station, and the trouble would thereby be located. The circuit in this case would measure the same or nearly the same as a break, for, in the case of a break, the ground-resistances C 0 would take the place of m and M The rheostats N and N having a large range are used to balance the circuits and keep the galvanometer-needle at any given point.

The stations, as shown, may be arranged with ordinary telegraphic instruments or with automatic signaling apparatus, as for police, fire, burglar, marine, or other electric signal-stations. In circuits where there is considerable resistance, either because of numerous stations, long lines, or from any other cause, I use the polarized relay made as shown in Fig. 2, the positive pole of which is here represented by the letters 19 p, and the negative-pole by the letters a p, and when economy of room is required I substitute the plunger-magnets shown in Fig. 3.

In a circuit of this character a person at the central station can immediately detect the location of any key that may have been closed by accident or design. For this purpose the amount of resistance at NY IV, &c., differs sufficiently, so that if K or K, or any other key, is closed I can by compensating locate the key closed by the amount of resistance added. The variance must not, however, be

sufficient to affect the working of the receiving-instruments This circuit would therefore be highly desirable for important worksuch as on railway telegraph-lines; but in such cases I would prefer to disconnect the wires from the grounds at E and E and use a metallic circuit, as shown by dotted line in Fig. 4, instead thereof. The batteries B and B would in this case be intermediate batteries, and a complete circuit would be formed from earth at E through C, battery B, the dotted line, battery B, to earth at E permitting full communication between the ter- -minal stations and all the stations on the circuit. Of course in this case, as soon as the break atsc is repaired there will be no ground in the circuit. A perfect telegraphic service would thus be assured. lVith a grounded circuit and apparatus any ground or break would immediately affect the galvanometer at the home-station, and by suitable attachments, the galvanometer-needle being provided with the electrode T and the dial with correspondent electrodes, as at S, the time of such break could be taken, the proper records made, and the break exactly located by com pensating for itthat is, by changing the resistance in rheostats N and N until the needle of galvanometers .I and J return to zero I can tell what resistance is missing. By means of this system the failure of operators to close their keys or to place the line to earth, in order that they may be communicated with when an interruption occurs, which renders ordinary circuits useless, will have no such effect here, and will enable train-dispatchers and other railway oflicials to command the movement of trains.

I-Iavin g thus described the action and benefit of my grounding device in different circuits, that which I claim as new, and desire to secure by Letters Patent, is-

1. In an electric circuit having a current at all times, and where an increased or decreased currentis used for signaling, the combination of two automatic grounding devices at each station, each device arranged to act independently of the other, and each device consisting of an electro-magnet, an armature controlled by said magnet and arranged to press against a grounded stop when no current is passing through the magnet, and a resistance-coil arranged to connect said grounded stop with the earth, all substantially as set forth.

2. In an electrical circuit having a current at all times, and where an increased or decreased current is used for signaling, two automatic grounding devices at each station, each device arranged to act independently of the other, and each device consisting of an electro-magnet, an armature controlled vby said magnet and arranged to press against a grounding-stop when no current is passing through the magnet, and a resistance-coil arranged to connect the grounding-stop with the earth, in combination with signaling-instruments placed between said grounding devices, substantially as set forth.

Signed at New York, in the county of New York and State of New York, this 24th day of March, 1887.

ARTHUR O. ROBBINS.

Witnesses:

HUG-H COLEMAN, J. B. SABINE.

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