US1256661A - Telephone-exchange system. - Google Patents

Description

H. P. CLAUSEN.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED APR. 24, 1917.

L5fi6L I Patented M019, 1918,

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HENRY P. CLAUSEN, OF MOUNT VERNON, NEW YORK, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

Specification of Letters Patent.

Patented Feb. 19, 1918.

Application filed April 24, 1917. Serial No. 164,231.

To. all 'whom it may concern Be it known that I, HENRY P. CLAUSEN, a citizen of the United States, residing at Mount Vernon, in the county of Westchester and State of New York, have invented certain new and useful Improvements in Telephone-Exchange Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone exchange systems, and is more particularly adapted to provide means for taking care of waiting connections. The particular objects of the invention and its uses will be apparent from a description of the embodiment of the invention.

The drawing illustrates diagrammatically portions of a telephone exchange system showing an embodiment of this invention.

Referring to the drawing and to the embodiment of the invention as shown therein. At Y is shown a telephone line which extends from a subscribers station Z to a central oflice W. The line Y is connected to the central oflice with a plurality of sets of terminals J, J, J,, J J It is preferred that these jacks or sets of terminals be grouped, corresponding terminals of each set of each group beinginterconnected. In the embodiment shown two groups are illustrated, J and J 3 constituting one group, and the other three jacks a second group. The line relay and the line lamp of the line are shown at C and D, respectively, preferably more closely associated with one of the jacks, for example jack J,. The other two jacks of this group may be what are known as multiple acks as here shown at different operators positions. All of the jacks are normally dis- .connected from the line. The jacks J and J which are at different operators positions, are adapted to be connected to the line Y by a relay A. A portion of the connecting or link circuit here shown as a cord circult is shown at V and a portion of another cord circuit is shown at U. The cord circuits U and V may be at different operators positions. Electromagnetic relays are shown at A, B, C, F, H and G. The relay F is of relatively low resistance and the relay B is.

sluggish or slow-acting for purposes which will appear in the description of the operation. At M is shown a special test tone device which produces in its circuit N a fluctuating current which is induced through the repeating coil 0 into acircuit including the conductor 40. I

The operation of the system is as follows, assuming that the subscriber at Z is connected through the line Y, the jack J and the plug P and cord circuit U with another subscribers line and conversation is taking place. Under these conditions relay A is ope-rated over a circuit from battery through sleeve contacts 42 and 41 of the plug P and the jack J, and the winding of relay A to ground, thereby closing the switches 9 and 10 and completing the connection of the subscriber Z to the cord circuit U. The connection through the cord circuit U to the other line will be understood, as standard equipment is employed. The sleeve contact A l of the jack J 3 will be at a potential for the purpose of giving the ordinary or normal busy test should this jack be tested, thereby preventing the connection of another cord circuit with the group of jacks to which jack J belongs and consequently with line Y. The operation of rela A also closes switches 2' and 3, connecting the special test tone equipment to the contacts 8, 8 and 8 of the jacks J,, J and J respectively, of the other group, so that should an operator test one of these jacks she would receive the special test tone from M. The switch 3 closes the circuit of the relay B, which opens the switches 5 and 6, disconnecting the line relay C and the line lamp B from line Y.

With the apparatus in this condition and the conversation between the subscriber at Z and the other subscriber connected to U in progress, it will be assumed that a sub-' scriber connected to the calling end S of the cord circuit V calls for a connection with the subscriber at Z. The operator at V tests the jack J, in the usual manner, and, finding that the line Y is busy, so informs the subscriber connected to the calling end S of the cord circuit V. Assuming that such subscriber is willing to wait until the termination of the conversation in which the subscriber Z is already engaged or for any other reason asks for a waiting connection, the operator controlling the cord circuit V tests either of the jacks J,, J 2 or J; whichever is most convenient, and receiving the special tone from the device M, is thereby notified that a waiting connection may be made with any one of these jacks, assuming that it is the jack J 1 that is tested, the plug P is inserted into the jack J completing a circuit through the relays G and F, each of which will be operated, the relay F opening the switch 7 and disconnecting the special tone apparatus M from the jacks. The relay G will operate, connecting the machine ringing equipment to the plug P by the use of apparatus in a manner well understood. The normal busy test will also be placed upon the contacts 8' and 8-through the sleeve 50 of the plug P. When the plug P was inserted into the jack J,, the relay H was connected in multiple with the winding of relay F, but H will not be 0 erated under these conditions, since it wi 1 not receive suflicicnt current to operate it as long as it is in multiple with the winding of relay F. While the subscriber connected at S is waiting, the conversation in which the subscriber at Z is already engaged is terminated and the operator withdraws the plug P from the jack J, interrupting the circuit of the relay A, which releases its armatures, whereupon the switches 2, 3, 9 and 10 will be opened, disconnecting the line Y from the jacks J and J The circuits of the relay B and of the low resistance relay F will thereby be opened, whereupon these relays release their switches. The opening of switch 2 breaks the shunt of the winding of relay H which is now energized. The energization of relay H onens the switches 11 and 12 before the slow-acting relay B has permitted the closing of the switches 5 and 6, thereby preventing the reconnection of the line apparatus C and D to line Y. The energization of relay H also closes switches 13 and 14, connecting the tip and ring springs of the jack J through to the line Y. Ringing current will immediately be applied to the line and the subscriber at Z recalled. As soon as this subscriber responds, he is placed in communication with the subscriber connected at S. The relay H also closes a switch 15, completing a second circuit for the relay B before the relay B had released its switches. Relay H also closes switch 16, connecting the. special tone apparatus M through the switch 16 and the conductor 60 to the sleeve contacts 41 and 44 of jacks J and J If now asecond operator were to test either the contacts 8' or 8", the ordinary busy test would be received, but if the sleeve contacts 41 or 44 be tested the special test tone would be received, indicatin that a waiting connection might be made with either ofthe jacks J or 7 It will be seen that this invention provides means capable of instituting waiting connections without interfering with the conversation progressing at the time such waiting connection is made. In fact, it is possible by the use of this invention to establish the waiting connections without actually connecting the second cord circuit to the wanted line. Just as soon as the first conversation is terminated and the wanted line freed, the apparatus will immediately and automatically complete the second connection. These results mav be and referably are accomplished without imposing any additional load or burdens upon the relays in the cord circuits.

What is claimed is:

1. In a telephone system, the combination of a telephone line provided with two groups of jacks, means to place the normal busy test on one group of the line jacks when a cord circuit is connected to one of the jacks test on each jack of the other group when a cord circuit is connected to a jack of thefirst group.

2'. In a telephone system, the combination of a telephone line provided with two groups of sets of terminals, a link circuit, means to place on all of the sets of terminals of a group the normal busy test when the link circuit is connected to a set of terminals thereof, and mechanism to place on each set of terminals of the second group a special tone test when the link circuit is connected'to a set of terminals of the first group.

3. In a telephone system, the combination of two groups of sets of switching terminals normally disconnected from the line, a link circuit, devices to connect each group to the from the telephone line, means acting automatically when the link circuit is connected to a set of either group to connect the telephone line to the terminals of the particular group and prevent the connection of the line to the terminals of. the other group,

means for placing the normal busy test on a terminal on each set of a group having the link circuit connected to the one set thereof, and means to place upon a terminal of each set of the other group a special tone test while the link circuit is connected to a set of terminals of the other group.

5. In a telephone system, the combination of a telephone line, a plurality of cord circuits, two groups of line jacks, each group having its terminals connected together and each group being normally disconnected from the telephone line, means for automatically connecting the telephone line to a group to which a cord circuit is connected and preventing the connection of the line to the other group during such connection, means for placing the normal busy test upon each jack of the group to which the cord circuit is connected, mechanism to place a special tone test upon each jack of the second group while the cord circuit is connected to a jack of the first group, and means to disconnect the special tone mechanism from the jacks of the second group and place the normal test thereon when another cord circuit is connected to a jack of the second group.

6. In a telephone system, the combination of two link circuits, two groups of sets of switching terminals, the corresponding terminals of each set in a group being interconnected, a telephone line adapted to be connected to the sets of terminals of each group, means for placing the normal busy test upon sets of terminals of a group to which a link circuit is connected, mechanism for placing a special tone test upon a terminal of each set of terminals in the second group when a set of terminals of the first group is thus engaged, and means for removing the special tone from the terminals in the second group and placing the normal busy test thereon when a second link circuit is connected to a set of terminals of the second group.

7. In a telephone system, the combination of two groups of line jacks, a cord circuit, a telephone line adapted to be connected to one group only at a time, the testing terminal of each jack in the group being connected to the testing terminals of the other jacks in the group, means for placing the normal busy test on the testing terminals of the jacks of a group when one of the jacks thereof is connected to the cord circuit, and mechanism for placing a special test tone on the testing terminals of the jacks of the other group when the cord circuit is connected to one of the jacks of the first group.

In witness whereof I hereunto subscribe my name this 20th day of April A. D., 1917.

HENRY P. CLAUSEN.

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