US2290335A - Repeater system - Google Patents

Description

Ju1y21,1942. 7 G, NER V 2,290,335

REPBATER SYSTEM Filevd Aug. 3, 1940 2 Sheets-Sheet 1 /m'bYU/' 5252777 .71.577527 1145,

July 21, 194.2. G. KINER 2,290,335

REPEATER SYSTEM Filed Aug. 3, 1940 2 sheets-sheet 2 Patented July 2l, 1942 29ans REPEATER SYSTEM Glenn Kiner, Harvey, Ill., assigner to Kellogg Switchboard and Supply Company, Chicago, Ill.,

a corporation of Illinois 8 Claims.

The invention relates, in general, to a telephone system for interconnecting lines terminating at a central station and more particularly to a system of the cordless type in which connections between the various lines are made by the use of connecting keys associated with connecting circuits for interconnecting the lines as calling and called lines.

The lines radiating from a central point, such as a dispatchers station, are usually of varying length. In a system of this type, the practice of including a gain control and balance network in the line circuit, with which each line is equipped, permits adjustment to the respective values of the lines, is well known, and in conjunction with a, repeater provides the needed energy to overcome the transmission losses on long lines.

An object of this invention is the provision of a line circuit and a connecting circuit arrangement in which relay means are provided controlled by the position of the connecting keys for including or excluding the gain control and balance network and repeater in a connection between lines as calling and Vcalled lines depending upon whether it is a connection between a long haul line and a short haul line or two short haul lines.

Another object of the invention is the provision of relay means in the line circuit which is operated by current received from either line while a connection remains in service to operate a disconnect signal or lamp to indicate to the attendant a disconnect or recall signal by either line of an existing connection.

Another object of the invention is the provision of relay means which remain normal to include a repeating coil in circuit between lines as calling and called lines when the connecting keys are positioned to exclude the balance network and repeater when connecting short haul lines as calling and called lines.

The above features, as well as others not specifically pointed out above, will be more fully pointed out in the following description taken in connection with the accompanying drawings comprising Figs. 1 and 2, taken together.

Fig. 1 illustrates a line circuit LC, there being one such line circuit for each line in the system and includes a repeating coil RC, a ringing relay RI which, when operated, connects ringing current to the called line from a ringing current source RS. A ring-up relay RU is actuated by the incoming signal from a calling line to operate a line relay LR which closes a circuit to light a line lamp signal LS. A supervisory relay SR affected when an incoming signal is received from either a calling or called line while the connection between substations remains in service controls the lighting of a disconnect lamp signal DS to indicate a recall or disconnect signal to the operator. A disconnect relay DR is provided and controls the elacement of the line lamp signal LS and also disconnects the operators leads from the line circuitLC. A connect relay CR is also provided which, when operated, connects the gain control pad GP and balance network BN into the circuit when a connection being set up between a calling and called line Vnecessitates the use of a repeater as will be more fully hereinafter described.

Fig. 2 illustrates' the key circuit arrangement KC which comprises connect keys CK, CK' and CK2 associated, respectively, with lines A, B and C shown in the drawings. The keys CK, etc, are used to establish connections between the lines of the system as calling and called lines and are of the two-position locking type for purposes as will be more fully hereinafter described. A connect control relay CC common to the keys CK, CK and CK2 is controlled by the operation or" the keys when moved to establish a connection between a calling and called line. A relay connector link circuit RL shown below the dash line in Fig. 2 comprises connect relays CO, CO and CO2 which are associated, respectively, with the lines A, B and C. A switching relay SW associated with the connector link RL, when operated, connects a suitable repeater of any well known type (as for example the one shown in U. S. Patent 2,050,292 to Eaton) which terminates at the terminals L, L', L2, L3, L4 and L5 of the connector link RL. The position of the keys CK, etc., control the operation of the switching relay SW when establishing a connection between a calling and a called line and determines the inclusion or exclusion of a repeater in the connection. A non-ring through repeating coil RC is also provided which remains connected between the calling and called lines when the relay SW does not operate.

Assuming that the system, as above outlined, requires lve such links RL to take care of the trafl'ic between the lines of the system, a key CK is repeated for such link RL, and therefore, each line will be equipped with live such connect keys.

Having described, in general, the apparatus which comprises the invention, a more detailed description of the invention will be given by tracing the operation of the system in establishing a connection between a calling and a called line.

The subscriber at the calling substation associated with the line A upon the initiation of a call operates the hand generator thereat and. current therefrom operates the ring-up relay RU of the line circuit LC associated with the calling line. The closing of front contact 2 of the relay RU operates the line relay LR from battery through the relay winding, back Contact of the disconnect relay DR, armature 3, conductor 4 to ground at front contact 2. Relay RU restores at the conclusion of the current fromV the calling station and the opening of its front contact 2 opens the initial energizing circuit of relay LR but the relay locks up through its front contact 5, conductor 6 to ground at back contact 1 of relay DR. The

closing of back contact 2 oi relay RU closes a circuit for line lamp signalv LS, traced from battery through the signal LS conductor 8, front contact 9 of relay LR to ground, at back contact 2 of relay RU. The line signal LS is lighted and the operator noting the signal actuates the listening key LK associated with the calling line to connect her operators set OS over conductors 9 and I0, front contacts II and I2 of the listening key LK, conductors I3 and I4 to the tip and ring conductors T and R of the line circuit LC through the back contacts I5 and I8 of the disconnect relay DR. The operator is now connected to the calling line and upon receiving the number of the Wanted line, determines whether the connection between the calling substation and the called substation necessitates the use of a repeater in the connection.

Assuming that the connection to be established with the called line necessitates a, repeater and that the called line is the line B, the operator vactuates the connect key CK associated with the calling line and the connect key CK associated with the called line to move them to the left or repeater connection position E. The closing of front contact I1 of the key CK operates the disconnect relay DR from battery through relay DR, conductor I8 to ground at front contact I1 of the key CK. Relay DR operating over this circuit opens the locking circuit of the relay LR at its back Contact 1 and relay LR restoring opens its front contact 9 to efface the line signal LS and the opening of back contacts I5 and I8 of the relay DR disconnects the operators listening leads I3 and I4 from the tip and ring conductors T and R of the line circuit LC.

The connect control relay CC associated with the key group, comprising connect keys CK, CK and CK2, is a marginally operated relay and requires the current from both` resistance R and R connected in multiple for its operation. The circuit through resistance R is traced from battery through relay CC, conductor I9, front contact 28 of key CK, conductor 2I to ground through the resistance R. The circuit through the resistance R' is traced from battery through relay CC, conductor I9, front contact 22 of the key CK conductor 23 to ground through the resistance R'. The relay CC is thus connected in multiple with the resistances R and R' and operates when two keys of the connecting circuit have been operated to close its front contact 24 to operate the network connect relay CR, from battery through the winding of relay CR of the line circuit LC associated with the calling line, conductor 25, front contacts 25 and 21 of relay CK, conductor 28 to ground at front contact 24 of relay CC. The relay CR closes its front contacts 29, 38, 3| and 32 to connect the gain control pad GP into the line circuit LC of the calling line. The ground at front contact 24 of relay CC also extends over conductor 28, through front contacts 33 and 34 of the key CK and over conductor 35 to the relay CR of the line circuit associated with the called line and operates to close its iront contacts to connect the gain control pad into the circuit. Relay DR of the line circuit of the called line is also operated by the closure of the front contact 35 of the connect key CK.

The ground at front contact 24 of the relay CC also energizes the connecting relays CO and CO' associated with the keys CK and CK. The circuit for relay CO extends from ground at contact 24 over conductor 28, front contact 21 of the key CK, conductor 31 to battery through the relay CO and the circuit of relay CO extends through front contact 33 of the key CK and conductor 38 to battery through relay CO'. The switching relay SW is also operated from battery through relay SW, conductor 48, front contact 4I of the key CK, conductor 31, front contact 21 of the key CK, conductor 28 to ground at front contact 24 of relay CC. Having previously assumed that the connection between the calling and called lines necessitated a repeater connection, the closing of front contacts 44 and 45 of relay SW connects one side of the repeater, connected to terminals L and L through front contacts 44 and 45 of relay SW, front contacts 46 and 41 of the connect relay CO and conductors 48 and 48 to the front contacts 30 and 3| of the relay RC of the line circuit LC of the calling line. The conductor 48 extends through the front contact 30, the windings R3 and R4 of the gain control pad GP, the front contact 29 of relay CR to the tip conductor T. The conductor 49 extends through the front contact 3| of the relay CR, the windings R5 and R6 of the gain control pad GP, front contact 32 of the relay CR to the ring conductor R. The closing of front contacts 50 and 5I of the relay SW associates the other side of` the repeater from terminals L2 and L3, through front contacts 50 and 5I, conductors 52 and 53, front contacts 54 and 55 of the relay CO, conductors 56 and 51, front contacts 58 and 59 of the relay CO to conductors 6) and 6I which extends through front contacts of the relay CR of the line circuit associated with the called line, windings of the gain control pad of the said line circuit to the tip and ring conductors of the same.

The operator having connected the calling line A with the called line B through the medium of the keys CK and CK', the ringing key RK associated with the called line is now operated by circuit ground, from the front contacts 62 and 63 of the ringing key RK actuates the ringing relay RI of the line circuit associated with the called line. Relay RI operates and closes its front contacts 64 and 65 to connect ringing current from the ringing current source RS to signal the subscriber on the called line B. The restoration of the ringing key RK opens the circuit of the relay RI which restores and disconnects the ringing current source RS. The called subscriber, in response to the call signal, removes the receiver and the talking circuit between the calling and called substations may be traced over the heavily marked conductors.

Upon the termination of conversation, the subscribers replace their respective receivers and actuate the hand generators to set up the disconnect lamp circuit to give the operator an indication that the conversation has terminated. Current from the calling line again operates the ring-up relay RU to close its front contact 2 to operate the supervisory relay SR, from battery through relay SR, conductor 66, front contact 3 of relay DR and conductor 4 to ground at front Contact 2. Relay SR locks up from battery through relay SR, its front contact 51, to ground at front contact 1 of relay DR. Relay RU deenergized when current from the calling substation ceased to close a circuit for the disconnect lamp signal DS from battery through the lamp DS, front contact 68 of relay SR, back contact 9 of relay LR to ground at back contact 2 of relay RU. Current from the called line operates the relay RU of the line circuit LC associated with the called line to light the disconnect signal DS in the same manner as just described. The lighted disconnect lamp signals DS of the calling and called lines indicate to the operator that conversation has terminated and the restoration of the connect keys CK and CK now takes place.

The restoration of the connect key CK interrupts the circuit of the relay CC at the front contact 2l! and the opening of front contact 24 of relay CC restores the switching relay SW, the connect relays CO and CO and the relay CR. The opening of front contact l1 of the key CK restores relay DR and the opening of front contact 1 of relay DR allows relay SR to restore which effaces the lamp signal DS at its front contact 68. 'I'he restoration of the connect key CK' restores the relay DR of the line circuit associated with the called line at its front contact 36 to eace the disconnect signal DS due to the restoration of the relay SR and relay CC, hav# ing restored, the connect relay CR is also restored. The apparatus used in establishing the connection, as above set forth, is now at normal and again available for establishing other connections.

The description between a calling and called line where it is not necessary to use a repeater, gain control pad and balancing network in the connection will now be described. Assuming that such a connection is to be established between the line A as a calling line and the line B as a called line, theconnect keys CK and CK' are moved to the right or the position F. The operation of the circuit is the same as previously described, but the energization of the relays DR of the line circuits associated with calling and called lines are operated through front contacts 69 and 'FS of the actuated keys CK and CK. Relay CC is also operated through the resistances R and R' in multiple but the circuits extend through the front contacts 'H and 'l2 of the keys CK and CK and relays CO and CO are also operated to ground at contact 2li through the front contacts 13 and 14 of the keys CK and CK. No energizing circuit for the switching relay SW of the link RL and relays CR of the line circuits, associated with calling and called lines, is closed as the circuit closing contacts which control the operation of these relays when the keys CK and CK' are in position E are not a part of the key contact arrangement when in its F position. The switching relay SW remaining normal, the repeating coil RC remains in the talking circuit between the calling and called lines through the back contacts 44, t5 and 50, 5I of the relay SW and as relays CR of the respective line circuits associated with the calling and called lines remain at normal the repeating coil is connected through normal contacts 29 and 3l of the relay CR to the tip and ring conductors of the respective line circuits. The repeating coil is of the non-ring through type and prevents ringing current from one line from operating the relay RU of the other line as is well understood. The disconnect signals DS of the respective calling and called line circuits are controlled in the same manner and disconnection of the lines as calling and called lines and the restoration of the apparatus used in establishing the connection is the same as previously described.

Having thus described my invention, what I claim is new and desire to secure by United States Letters Patent is:

1. In a cordless type telephone system the combination of line circuits and a connecting circuit, amplier means including a g-ain control means and a balancing network, keys for connecting said circuits, relay means in said circuits acting in response to the position of said keys to include or exclude said amplier means from said circuits, a repeater coil, and relay means arranged to include said coil in the circuit when the said relays are operated so as to exclude the sai-d amplifier.

2. In a cordless type telephone station system the combination of line circuits and a connecting circuit, amplier means including a gain control means and a balancing network means, keys for connecting said circuits, and relay means in said circuits acting in response to the position of said keys to include ysaid amplifier means in, or exclude it from said circuits.

3. In a cordless type telephone system the combination of line circuits and a connecting circuit, a gain control means and a balancing network means, arranged to be connected in said line circuit, and repeater means, adapted to be included in said circuit, connecting keys for connecting said circuits, and relay means in said circuits acting in response to the action of said keys to include said gain control and balancing network means in, or exclude it from said circuits.

4. In a telephone system, line circuits, a connecting circuit, keys in said connecting circuit, one for each line circuit, amplifier means, relay means for connecting said pair of line circuits and including in said connection said amplifier means, a circuit for actuating said relay means controlled at contacts of said keys corresponding to the connected lines, and means whereby said relay means is notJ operated until the two keys are actuated.

5. In a cordless type telephone system the combination of line circuits and a connecting circuit, amplier means including a gain control means and a balancing network means, keys for connecting said circuits, a repeating coil, relay means in said circuits acting in response to the position of said keys to include or exclude said means from said circuits, and when excluding said ampliier means to include said coil.

6. In a cordless type telephone system the combination of a line circuit and a connecting circuit, ampliier means including a gain control means and a balancing network means, keys for connecting said circuits, and relay means in said circuits acting in response to said keys to include said amplifier means in, or exclude it from the connected circuits.

7. In a telephone system, line circuits, a connecting circuit, variably operable keys in said connecting circuit, one for each line circuit, am-

plier means, a repeater coil, relay means acting 'in response to the position of the said keys corresponding to a pair of line circuits for connecting said pair of line circuits and including in said connection said amplifier means, or excluding said amplier means and including said repeater coil according to the position of said keys.

8. In a telephone system, line circuits, a connesting circuit, variably operable keys in said connecting circuit, one for each line circuit, am- 10

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