US315658A - Multiple switch-board - Google Patents

Description

(N0 Modem 2 Sheets-Sheet l. T. J. PERRIN.

MULTIPLE SWITCH BOARD. No. 315,658. Patented Apr. 14, 1885.-

(N0 ModeL) 2 Sheets-Sheet 2. T. J. PERRIN.

MULTIPLE SWITCH BOARD.

WITNESSES R] Thoma 8 J ferrz'n,

By his %ney6 UNITED STATES -ATnNT Orrrcis.

THOMAS J. PERRIN. OF BROOKLYN, YORK, ASSIGNOR TO CHARLES P. HUNTINGTON, OF GREENVILLE, MISSISSIPPI.

MULTIPLE SWITCH-BOARD.

SPECIFICATION forming part of Letters Patent No. 315,658, dated April 14, 1885.

Application filed November 4, 1884. (No model.)

To aZZ whont it may concern: 7

Be it known that I, THOMAS J. Pnnnnv, of Brooklyn, Kings county, New York, have invented certain new and useful Improvements in Multiple Switch-Boards, of which the following is a specification.

The object of my invention is to improve the efficiency of operaton of such boards and at the same time to reduce them to great sim- 10 plicity of structure.

In the accompanying drawings, Figure l is a diagram view illustrating portions of two sections, X and Y, of a multiple system of boards; and Fig. 2 is a detail view, partly in section and diagram, showing a pair of corresponding terminals on the two sections of board.

In Fig. 1 I have shown on each board eight terminals merely, and will assume that the operator at X has charge of terminals from 1 to 4, inclusive, and that the operator at Y has charge of terminals 5 to 8, inclusive. Each line is equipped with an annunciator and a relay, as shown. The circuits, however, from the annunciators to the relays are omitted in this figure, as it will be difficult to properly illustrate them, and they are shown in complete detail in Fig. 2.

I have indicated two lines as connected on the boards-that is, line No. 1, which is in special charge of the operator at X, and line No. 8, which is in charge of the operator at Y. As all the lines are similarly connected I and equipped, a description of one will be sufficient, and further illustration is therefore unnecessary. front and back plates, A B, between which at each line terminal a tubular electromagnetic coil, 0, without a core, is secured. The front and back plates, A B, are bored through in line with the opening through the coil, as clearly shown in the drawings; and in the face B of the board around each of said openings is set an annular metallic plate or ring, a, with which the main line is connected, as will be presently described. Suppose now that in Fig. 2 the terminals illustrated are, say, No. 1 terminals on boards X and Y. A circuit from a local battery, L B, one pole of which is The boards are formed with grounded, passes from the battery through the coil 0 at station X out of the coil to a contact, a, against which a spring contact, I), normally presses, from said springcontact through the coil of the magnet O at station Y, to the contact a and spring contact-arm b,- thence by wire Zb through the coil of the relay Rof line 1, after which it branches, one branch being connected with the lower contact-stop, r, of the armature R of the relay R, while the other branch is connected with the lower contactstop, 8, of the armature of the annunciator S, both branches of the circuit being normally open at these contacts, as clearly shown in Fig. 2. The main line, which is marked 1 in Fig. 2,, enters the multiple system of boards, and is directly connected, as shown at Y, Fig. 2, with all its terminal rings 0 on all the boards, such as Y, other than its particular board. At board X, however, where the operator is in special charge of this line, the line passes first through the coil of the annunciator magnet S, and thence to a point, t, where the circuit divides, one branch passing to the ring-terminal c. The other branch is connected with the rear end of the armature S of the annunciator,

which is permanently connected by the wire a with the upper contact, R", of the relay-armature R. This armature, which is normally in contact with its contact R as clearly shown in Fig. 2, is permanently connected at its front end through a bar, 9, with the earth. The upper contact, U, of the annuuoiator-armature is connected with the operators instruments, as shown.

V is the ordinary aununciator dr0p. An 8 insulated contactplate, t, is arranged on the faces of-the boards near each terminal ring c, as clearly shown, and is connected, as shown, by the dotted line i with the lower contactstop, r, of the relay-armature R. Assuming now that a call is sent to the central office over line No. 1, the current will pass through the coil of the magnet S of the annunciator, thence from the pointt by way of the end of the armature S, thence by wire 8 to the rear contact, R of the relay-armature R, and through said armature and the ground-bar r to earth. This current energizes the magnet S, causing it to attract its armature and let the annunciatordrop V fall, thus indicating that the call has been received. At the same moment the contact of the armature S with its front lower 5 stop, 8, will complete the local circuit Z b from said contact through the armature S, line 8 and relay-armature It, to ground. This com- 'pletion of the circuit will energize the relayinagnet R, which attracts its armature R and I opens the ground of the main line and local just traced at the contact R so that the an nunciator-armature S will go to its upper front contact, U, and throw the operators instruments into the main line. The local Z b will, however, be simultaneously closed through the contact-stop r, armature R, and contactstop 1", to ground.

The operator, upon being informed what line is wanted by the subscriber calling, will proceed first to test the terminal of that line to ascertain whether it is in use or not, and this is done in the following manner: The

completion of the local circuit Z 11, as just described, causes a current of electricity to flow 2 through the coils O at both sections of the board X and Y. To ascertain, therefore, whether the line of any particular subscriber is in use, I use a pair of soft-iron plugs on the ends, E, of each cord for connecting sub- 0 scribers. When this plug is inserted through the ring 0 into the hollow axis of the coil 0 at the terminal of the line to be tested, the plug becomes a core for the electromagnetic coil, and is at once magnetized. If, therefore, the 3 5 plug on the other end of the cord is touched to the plug in the terminal it will be attracted if there is any current flowing in the local, and the operator will know that the line is in use. If the line wanted is not in use, the op- 0 erator calls up the subscriber,as follows: He

touches one of the plugs E to an ordinary calling-battery bar, the use of which is well understood, and then touches the other plug to the insulated contact t. This completes a cir- 4 5 cuit from the calling-battery through the plugs and cord, contact t, wire 15, contact r of relay, coil of relay, and thence by wire Z I), through the various coils G of that line on the several boards to the local battery L B and ground. The polarity of the calling-battery will be such as to coincide with the local battery L B in causing a current to flow in this circuit. The relay-magnet of this particular line, at whatever board it may be, will therefore be energized and attract its armature B. This completes the local circuit, as before traced, from the relay-coil R, contact 1", relay-armature R, and ground-plate r, to ground. The local circuit of the called line is therefore established in the same way as just described, in connection with a calling subscriber. The action of the relay R will break the main line of the called subscriber at the contact R so that when the operator now plugs to the terminal of the line wanted and calls with his battery in the ordinary way, the annunciator-drop of that line at its particular board will not fall, and no confusion will therefore arise. The two lines are connected in the ordinary way, and the annunciator-drop V of the calling subscriber put up so as to connect the opera tors telephone out of circuit. Of course, as it will be perceived, when two lines are connected for conversation, the annunciator-coil S of the calling subscriber will be included in the line between the two subscribers. When,therefore, they have finished conversation, an impulse of electricity sent over the line by either subscriber in any ordinary way will cause the annunciator-armature to drop, thus throwing the operators telephones into the line again, and at the same time by the falling of the drop indicating that they have finished conversation. Before withdrawing the plugs from the respective terminals to disconnect the lines the rod 6, which moves endwise within the plug E in the calling subscribers terminal, is thrust forward by means of a lug, e, which projects from the side of the plug through an elongated slot therein. When the rod e is thrust forward, it breaks the local. circuit 1 b at a b, so that the relay R is demagnetized, and the apparatus in the line of the calling subscriber returns to its normal condition. (Shown at X, Fig. 2.)

Under the arrangement shown the operator at any board can readily ascertain whether any line is in use. At the same time, by the use of the insulated contacts if placed in branches of the local circuits of the several lines, any subscriber may be called without danger of causing his annunciator to fall.

I claim as my invention- 1. The combination, in a multiple switchboard, of a main line, its terminal on each of the boards, an electric coil at each of said terminals, a local circuit in which said coils are included,the annunciator S, and relay R, and electric circuits and connections,substantially as set forth.

2. The combination, in a multiple switchboard, of the main line, its terminals on the several boards, an electromagnetic coil at each too of said terminals, a local circuit in which they are included, a movable contact included in said, local circuit at each terminal, the annunciator S, and relay R, their circuits and connections, and a line-plug for making connections by means of which the local may be broken at its movable contact when the line is to be disconnected from that of another subscriber.

3. The combination of the line terminalplate a, the electro-magnet coil, the local circuit in which said coil is included, the movable contact in said localv circuit, and the plug formed with a movable slide or rod for opening the local circuit at said movable contact.

4. The combination of the main line, its terminals on the several boards, an electro magnetic coil without a core at each of said terminals, a local circuit in which it is included, and a pair of iron plugs, for the purpose set forth.

5. The combination of the several sections of board, a main line, a metallic terminal or ring for said line on each board, a direct connection between said terminals and the main line at each board except the particular board to which the line belongs, an annnnciatormagnet placed between the line and its terminal at its particular board, the operators instruments which are thrown into the line by the fall of the annunciator-drop, and electric circuits and connections.

6. The combination of the several sections of board, a main line, its terminals on the several boards, a local circuit for said line, the coils in the local circuit at the several terminals of said line, the annunciator at the particular board of said line, a relay included in said local circuit by means of which the ground of the main line is thrown off and the l ground of thelocal completed, an insulated I contact arranged in proximity to each of said line terminals, and the electrical connection between said contacts and the local circuit.

7. The combination of the several sections of board, the main line, its several terminals, a local circuit which on its completion indicates at the several terminals of said line that the line is in use, an annunciator for said line at its particular board, a relay also at said board by which the ground of the main line through the relay is thrown off and the local circuit grounded when the relay is energized, an insulated contact at each of said terminals, and the electrical connection between said contacts and the local circuit, for the purpose set forth.

In testimony whereof I have hereunto subscribed my name.

THOMAS J. PERRIN.

Witnesses:

J AS. PosnY, WV. J. OLINE.

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