US1400583A - Telephone system - Google Patents

Description

J. F. TOOMEY. TELEPHONE SYSTEM. APPLICATION FILED APR. 18. I918.

' Patented Dec'.20,1921.

2 SHEETS-SHEET I.

v INVENTOR. JFJbom BY l I l I l LINES. vtikthnhi ATTORNEY APPLICATION FILED APR. 18, 1918 Patented Dec. 20, 1921.

2 SHEETS-SHEET 2- i n R 5 ILL i i FEM" i I I I i I 'JNVE BY Lt ATTORNEY ill illfil) STATES PATENT JOHN F. TOOMEY, OF NEVJ YORK, N. Y., ASSIGNOR T0 AMERICAN TELEPHONE AND TELEGRAPH COMPANY, A CORPORATION OF NEW YORK.

TELEPHONE SYSTEM.

Specification of Letters Patent.

T 0 all whom it may concern Be it known that I, JoI-IN F. TOOMEY, residing at New York, in the county of New York and State of New York, have invented certain Improvements in Telephone Systems, of which the following is a specification. I

This invention relates to telephone switchboards and particularly to arrangements associated with a long distance transmission line at a central office. A

In practice a long distance transmission line may be associated with a plurality of different switchboards and positions at a central office. At one switchboard, positions may be provided for handling .outgoing calls over the line, and calls coming in over the line may be taken care-of at positions on other switchboards. In addition it may be found-desirable to have the line connected with other boards and positions suitable for purposes of testing and supervision. If a connection is made with the line at any one of the positions associated therewith, it is desirable to notify the operators at all the other positions on the line that the line is busy so that no attempt will be made to make connections therewith. Accordingly one of the objects of this invention consists in the provision at a plurality of the positions connected with a long distance transmission line in a central oflice of means for indicating whenever the line is being used.

At periods, such .as at night, when a decrease intraffic might warrant a decrease in the operating force at a central office, it may be found desirable to have both the incoming and the outgoing calls over the long distance line handled at positions on a board which would normally be used only for one type of call, such as the'board used for outgoing calls. In instances when a call is recelved at an incoming board which requires the attention of a through operator, such as an operator at an outgoing board, it is desirable to transfer such a call to an outgoing board. Accordingly further objects of the invention consists in the provision of means, which will operate when desired, to inform the operators at positions .on the outgoing board that there is an incoming call on the line which it is desired that they should handle. Other and further objects of the invention will be clear from the detailed description to be given later.

In the arrangements of this invention there is provided at the positions with which the long distance line is associated, a plurality of drops which, when operated, serve as busy signals to show that the line isbeing used. These drops are all connected to a common conductor so that, when a source of current is connected thereto, all of the drops will operate. The ringing current from a call coming in over the long distance line will operate a relay included in a bridge across the line which will operate. relay means under its control to connect a source of electrical energv to the common conductor leading to the drops, thereby causing them to operate, and to close a circuit: through the signal lamps located at po-' sitions on the incoming board. If it be found in single instances that an incoming call requires the attention of an operator at an outgoing board, a plurality of switch ing means are provided which serve to close the last mentioned circuit through signal lamps at positions on the outgoing board instead of at the incoming board. If operators at positions on either the incoming or outgoing boards make a connection with the transmission line, a circuit will be closed over the conductors connected to the sleeve contacts of jacks at such positions and through one of the'two windings of another relay. This relay serves to deenergize the aforementioned relay means and to extinguish the signal lamps, and substitutes further means for connecting a source of elec trical energy to the common conductor leading to the drops. If the operator at the test board makes a connection with the line a circuit will be closed over the conductor leading from the sleeve of the jack at the test board about the winding of another relay. The operation of this relay se ves to energize the above mentioned relay with the double winding. which functions, as formerly, to extinguish the signal lamps and to understood with reference to the accompany- Patented Dec. 20, 1921.

ing drawing, in the Figs. 1 and 2 of which,

when taken together, is illustrated a circuit diagram of the preferred form of the inven tion. Connected to the long distance transmission line L at the central office, are shown the switchboards A, B, C and D. Board A is used for testing purposes, and includes a position at which is located suitable switch ing means, such as the ack J The board B is used for handling incoming calls over the line L and may include a plurality of positions, each having suitable switching means, such as the jacks J and The board G is used forha-ndling outgoing calls over the line L and may include a plurality of positions, each having suitable switching means, such as the jacks J J J and J,. The board 1) is used forpurposes of supervision, and includes a position with switching means, such as the j acl: J At each of the positions on the boards B, C and D are provided drops, or busy signals, such as the drops 16, 17, 18, 19, 20, 21 and 22. These drops are connected by the conductors 14: and 15 to a common conductor 12. Bridged across the transmission line L is the relay 1,

which responds to ringin current coming in over the line. Under control of the relay 1 is shown the relay 2, which operates to connect a source of electrical energy to the common conductor 12, leading to all the afore mentionedbusy signals or drops. The relay 2 also serves to close the circuit through the signal lamps27 and 28, located atzpositions on the incoming board B. For therpurpose of handling incoming calls during certain perlods, such as at night, at the outgoing board 0, the'switching means K are pro? vided, which serve to cause circuits to be closed uponthe operation of relay 2 through the signal lamp 32, located at a position on the outgoing board C, instead of closing circuits, as formerly, through the signaling means at the incomingboa'rd BL When it is desired in single instances'to switch an incoming call to .the outgoing board C, the switching means. K and K, are provided at the incoming board B. Under the control of these switchingmeans is the relay 5, which when operated allows the circuit closed by the operation of the relay 2 to be completed through'the signal lamp 31, located at a position on the outgoing board C. Connected to the sleeve contacts of the jacks at the incoming board by the conductor 34 and connected to the sleeve contacts of the jacks at the outgoing board C by the conductor 36,

is a relay 3 with a double winding. When a connection is made with the transmission line at any of the positions on the boards B or C, the relay? will be operated and con- .nect a source of electrical energy to the common conductor 12, and accordinglvoperate the beforementioned drops or busy signals.

Connected to the sleeve contact of the jack at board A is the relay 4:. When a connection is made with the transmission line'L; at the board A, the relay 1 will operate and lose a circuit through the beforementioned relay3, which will function, as fo1'rner'ly,to connect the source of electri al energy to the conductor'leading to the drops or busy sigopening the bridge across the transmission line, which includes the, relay 1, and for deenergizing the relay 2, which controls the operation of all the signal lamps. V

The invention may now be more fully understood from the following description of its operation: When a call comes in over the long distance transmission line L ringing current will be transmitted over the bridge, including the conductors 6 and the winding'of relay 1, which becomes energized. 'The operation of relay 1 closes the followin circuit From ground, armature andcontact of relav 1, conductors 7 and 8, winding ofrelay2, conductor 9, to battery and ground. .The closing of this circuit energizes relay 2, which becomes locked up over the following circuit :-From ground and battery, conductor 9, winding of relay2, right-hand contact and armature of relay 2, conductor 10, left-hand middle contact of relay 3to ground. Operation of relay 2 serves to close the -following circuit :-'From ground and battery, left-hand middle armature and contact of relay 2, over conductors 12, 1 1 and 15 to the drops 16, 17 18, 19, 20, 21, and 22. The closing of this circuit operates the above-mentioned drops, or busy signals, and informs the operators at the various positions and switchboards that the long distance line is in use; The aforementioned operation of relay 2'also closes the following circuit :-From ground and battery, conductor 9, left-hand armature and contact of relay 2, over conductors 11, 23 and 24:, upper contact of key 7K over conductor '26 to the filaments of signal lamps 27 and 28 to ground. This operates the signal lamps 27 and '28, located at the incoming board B, and thereby informs the" operators at positions on this board that there is an incoming call on the long distance line L which it is desired that they should handle.

At periods, such as at night, when a de- 110 crease in traflic might warrant a decrease in the operating force at a central oilice, the key K is thrown. Incomingcalls over the line L will, in thesame manner as has been formerly pointed out, operate the re- 115 lays 1 and 2. Relay 2 Will, in the same manner as formerly pointed out, operate the drops or busy signals;- The circuit formerly closed by the operation of relay 2 through the signal lamps 27 and 28, will there is an incoming call on the line which it 1s desired that she should handle.

When an operator at an incoming board finds that an incoming call requires the at tention of an operator at an outgoing board, the switching means K or K located at positions on the board B, may be operated. The operation of the key K closes the followin circuit :From ground, contact of key 1 5 conductor 29, winding of relay 5 to: battery and ground. The closing of this circuit will energize relay 5. The incoming call over the line L will, in the same manner as has been formerly pointed out, operate the relays 1 and 2. Due to the energization of the relay 5, the signaling circuit closed by the operation of relay 2 will now be as follows :-From gound and battery, conductor 9, left-hand armature and contact of relay 2, conductor 11, right-hand contact and armature of relay 5, over conductor 30, filament of signal lamp 31 to ground. The closing of this circuit will operate the signal lamp 31, located ata position on the outgoing board C, and will notify the operator at such a. position that there is an incoming call on the line L,, which it is desired that she should handle. Jpon the closing of this last-mentioned circuit, the relay 5 will become locked up over its right-handing winding. A similar operation will take place should the key K, be thrown, and the de scription thereof will be omitted.

If a connection is made with the trans mission line L at positions on the board B by the switching means J 2 or J,, a potential from a source in the link circuit will be ap plied over the following circuitz-Slleeve contact of jack J conductors ll and 34,.

left-hand windin of relay 3, over conductor 35, left-hand middle contacts of relay 5 to ground. This will energize the relay 3. The

energization of relay 3, by pulling up its right-hand armature, connects a source of energy to the conductor 13, leading to the common conductor 12, which leads to the drops or busy signals. By this means the busy signals will remain in operation after the relay 2 has ceased to operate, and until the connection with the transmission line at the board B is terminated. The operation of the relay 3, by pulling up its left-hand armatures, opens the locking circuit ton. merly closed through the winding of relay 2, and opens the bridge across the transmission line, including the conductors 6 and the winding of relay 1.. If a connection is made with the long distance line L, at any or" the position on the outgoing board C by the switching means such as J J J .or J,, a potential from a source in the link circuit will be applied over the following circuit From the sleeve contact of one of said switching means, over conductors 36 and 42, right-hand winding of relay 3 to ground.

By the closing of this circuit the relay 3 will become operated and will perform the same functions as previously described.

It a connection is made with the long distance line L, at the board A, by the jack 3,, a potential from a source in the link circuit will be applied over the following circuit:--Sleeve contact of jack J over conductor 37, winding of relay 4, conductor 38, resistance 39 to ground. The closing of this circuit will operate the relay 4. The operation of relay a closes the following circuit From ground and battery, resistance 43, cont-act and armature of relay 4, over conductor 4-2, right-hand winding of relay 3 toground. The closing of this last-mentioned circuit energizes the relay 3, which will accordingly function in the same man nor as previously pointed out to operate the drops, to hold open the bridge including the relay 1 and to hold open the locking circuit about the relay 2. The operation of relay 4 also serves to apply a busy potential to the conductor terminating at the sleeve contacts of the jacks at the board C so that they will test busy.

While the invention has been disclosed as embodied in certain specific arrangements which have been deemed desirable, it will be understood that it may be capable of embodiment in many other arrangements without departing from the spirit of the invention as defined in the appended claims.

What is claimed is:

1. In a telephone exchange system, a trunk transmission line terminating at a central oiiice in a plurality of sets of switching terminals located at different switchboard positions, indicating means located at a plurality of said switching terminals, signaling means located at one of said last mentioned sets 01 switching terminals, and means responsive to current coming in over said transmission line for operating said indicating means and said signaling means.

2. in a telephone exchange system, a trunk transmission line terminating at a central other: in a plurality of sets of switching terminals located at different switchboard positions, indicating means located at a plurality of said switching terminals, sig naling means located at one of said last mentioned sets of switching terminals, a relay included in a bridge across said transmission line and responsive to current coming in over said transmission line, and means controlled by said relay for operat ing said indicating means and said signaling means.

3. In a telephone exchange system, a transmission line terminating at a central ofiice in a plurality of sets of switching terminals, a line relay connected with the transmission line, indicating means actuated upon i116 energization of said line relay, link circuits for extending the transmission line, a relay associated with a plurality of said sets of switching terminals and operating upon connection of one of the link circuits therewith to disconnect said line relay from the transmission line and to continue the operation of said indicating means, and a relay associated with another of said sets ofswitching terminals and responsive to the connection of a link circuit therewith to cause the operationoof the relay associated with said other sets-of switching terminals.

4:. In a telephone exchange system, a

' transmission line terminating at a central oflice ina plurality of sets of switching ter 'minals, indicating means located at a plurality of said switching terminals, link circuits for extending the transmission line,- a

trolled by said second mentioned relay for altering the electrical potential of terminals at another ofsaid sets ofswitching terminals.

In testimony whereof, I have signed my name to this specificationthis 5th day of April, 1918. v

' 7 JOHN F. TOOMEY.

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