US1387270A - Signaling and telephone system - Google Patents

Description

C. W. KECKLER.

SIGNALING AND TELEPHONE SYSTEM.

APPLICATION FILED MAR.27,1918.

Patented Aug. 9, 1921.

UNITED STATES PATENT G net CHARLES W. KECKLER, OF NEWARK, NEW JERSEY, ASSIGNOR TG WES TERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A GORPORATIQN-QF NEW YORK.

SIGNALING AND rnnnr ionn SYSTEM.

Specification of Letters Patent. Patgnted Aug. 9 1%)21;

Application filed March 27, 1918.

To all whom it may concern:

Be it known that I, CHARLES W. Knox- LER, a citizen of the United States, residing at Newark, in the county of Essex, State of sating signaling current, and in accordance with this feature, a plurality of relays are associated in such a way as to produce pulsating currentcfrom a direct current source for application in a signaling circuit.

Another object is the direct provision of local battery to any intercommunicating station in connection with a trunk line and in accordance with this feature one of the relays also serves as an impedance means on establishment of the talking circuit.

Other objects and features of the invention will be apparent from the following specification.

In the drawing, which diagrammatically illustrates one embodiment of the present invention, three stations of an intercommunicating system are shown together with a trunk line extending to an exchange; the answering jack shown to the left of the dotted line being located at this exchange.

and the apparatus to the right thereof being at the intercommunicating end of the trunk.

The stations A, B and C of the intercommunicating system shown are of the usual type in which connection between stations is obtained by depression of selective keys such as A, B and C through whichcconnection with the line conductors of the station called is made and such station signaled. On operation of the signal at any station response is made by depressing the home key H at such station and removing'the receiver from the switchhook in. the usual manner. The depression of the 'home key connects the set of the called station to its line conductors and a talking circuit is thus establishedbetween such stations, talking Serial No. 224,923.

current being supplied from talking battery 10 to each of such stations through impedance coils 11 located thereat.

The intercommunicating keys, with the exception of the home keys H, have three positions, namely, normal position i as shown on the drawing; way-down or signaling position in which the first and second, and third and fourth contacts are engaged and in'which the third contact is also engaged with the bus bar 12 connected with ringing battery 13; and intermediate or talking position in which the conditions are the same as for the signaling position except that there is no engagement with the bus bar 12. The home keys H need only have-a normal and an intermediate position since it is not necessary that any of the contacts thereof engage the bus bar 12 under any conditions. A locking plate 14 looks any depressed key in intermediate position until itis released by depression of another key.- 7 1;

Such stations of the intercommunicating system as it is desired to provide with trunk service will be equipped with a trunking key T similar to the intercommunicating keys and operable to connect its station to the trunk line 15,15 through conductors 16, 16. All three stations are shown as having such trunk connections but obviously it could be omitted at certain stations without interfering with the operation: of the intercommunicating system.

In describing the trunking arrangement, the operation which takes place on an intercommunicating station seeking connection with the exchange at which the-answering jack 17 is located will first be outlined;

Assume that station A desiresfsuch a connection. The key T at station A is depressed to signaling position, thereby engaging the third contact thereof with the bus bar 12 and completing an operating circuit for the relay 18. This circuit extends from one side of battery 13, conductor 19,

bus bar '12, third contact of key :T, conductors. 16:, 15 and 20, armature andnormal contact of relay 21, conductor 22, winding of relay 18, and conductor 23 to theother sideof battery 13. TherelaylS is accord ingly operated, disconnecting thetrunk sig n-al 24 from the trunk, line and connecting a local battery 25 across the trunk conductors 15,; 15.. Current therefrom'flows momentarily over theline conductors 15 andw15 and through the winding of the answering signal 26 at the exchange. Another path is also providedthrough one of the windings of the relay 21 which, as shown,'has a plurality of windings. This path begins at the upper side of battery 25 and extends over conductor 27 upper armature and alternate contact of relay 18, conductors 15 and 35, and lower winding of relay 21 to the lower side of battery 25. A condenser 28 is provided in the conductor15' between the connection of the lower armature of relay 18 and the conductor 20 and prevents the energization of the upper winding of relay 21 at this time. Under these conditions the armature of relay 21 will be attracted, opening the circuit pre viously traced for relay 18, which is thereby deenergized and its armatures retracted. This interrupts the flow of battery to the signal 26 and also opens the energizing circuit for the lower winding ofrelay 21. Its armature accordingly returns to normal position, reestablishing the circuit for relay 18. Operation of relay 18 again supplies battery to the signal 26 and also actuates the relay 21, as previously explained, to'open the circuit of relay 18. This action is repeated so long as the key T is maintained in signaling position and the pulsating current thus generatedwill actuate the signal 26 at the exchange, indicating that a party is calling. It is only necessary to retain key T in signaling position momentarily in order to actuate the signal 26, and thereafter it is permitted to return to intermediate position, and the calling party removes the receiver 29 from the switchliook 30 to complete the talking connection with the trunk line. The key T being out of signaling position, the relay 18 cannot be energized, but on closure of the switchhook 30, a talking circuit is established through the relay 21 to supply local battery to the station associated with the trunk. This circuit extends. from upper side of battery 25, conductor 31, upper winding of relay 21, conductors 20, 15 and 16, third and fourth contacts of key T, conductor 32, switchhook 30, receiver 29, transmitter'33, conductor .34, second and first contacts of key T, conductors 16, 15 and 35 and lower winding of relay 21 to the lower side of battery 25. The windings of relay 21 accordingly serve as impedance means for talking current supplied to stations connected with the trunk line while the provision of the condenser 28 in the trunk conductor 15 prevents direct current battery being supplied to the exchange end of the trunk, though permitting the passage of the fluctuating voice currents therethrough to telephonically connect the "intercommunicating sta tions with the exchange.

The operator at the exchange on observing the signal 26 would answer by plugging into the jack 17 and establish connection with the line desired in the usual manner, talking current being supplied to the exchange end of thetrunk line from the battery of the exchange (not shown) or in any other desired manner. 7

. On establishment of a talking connection with an outside station the parties would converse in the usual manner, and due to the .fact that relay '21 is operated when an inter communicating station obtains a talking connection with the trunk, the depression of the trunk'key T of other stations to signaling position will not develop signaling current, inasmuch as the circuit of the relay 18 is open at the armature of relay 21. Ohviously, were such current generated it would cause annoyance through the development of unpleasant noises in the receivers of the parties talking.

at termination of conversation the parties restore their receivers to their respective switchhooks. The party at station A thereupon depresses key T to lowermost position, operating relays 18 and 21 as before, and impressing pulsating signaling current on conductors 15 and 15 to thereby operate the disconnect signals (not shown) at the exchange. The exchange operator thereupon withdraws the plug (not shown) from the jack 17', while the party at station A would open the talking circuit atth'e switchhook 30, whereupon the relay 21 would be restored to normal. Alter signaling to disconnect the key T at station A would return to and be held in intermediate position but would not interfere with the operation of the system, inasmuchas the talking circuit thereat would be open at the switchhook '30. The key TY would, however, be released to normal position on another key being depressed in obtaining another connection.

In order tov answer calls received through the exchange the trunklinc is shown as provided with a signal 2%,normally bridged across the conductors and operated by sig naling current from the exchange. This signal would be located so as to be convenient to at least one of the intercommunicating stations. The station observing the signal would remove the receiver 29 from the switchhook 30 and depress trunk key T thereat to intermediate position, thereupon completing atalking connection with the trunk line as previously outlined. The relay 21 would be actuated thereby and prevent the momentary application of signalingcurrent from battery '25 to the trunk even should the key T be depressed to signaling position in actuation.

It will be observed that when an intercommunicating station signals the exchange the operation of relay 18 opens the bridging circuit of the signal 24 during the application of signaling current to the conductors 15, 15 so that even should signal 24 be operable on the pulsating current developed through the cooperation of the relays 18 and 21 it will not be actuated to the annoyance of the party signaling. The operation of relay 18 further prevents the formation of a parallel path through the signal 24: for the signaling current generated, so that the answering signal 26 at the exchange will be sure to receive a sufficient amount of current to operate satisfactorily. The signal 24: al-- though bridged across the circuit during talking is preferably of such high impedance that it will not materially interfere with the transmission.

Vhat is claimed is:

1. A telephone system comprising a line, a signal connected therewith, telephonic apparatus, a source of current, switching means, a relay energized upon the actuation of said switching means to connect said source of current with said line for operating said signal, and a second relay operating as a result of the energization of said first relay to cause the deenergization thereof and operating independently of said first relay as a result of the connection of said telephonic apparatus with said line.

2. A telephone system comprising a line, a signal associated with said line, a subscribers set for telephonic association with said line, a source of direct current, a relay operable to connect said source of current with said line, an operating circuit for said relay, a second relay operable to open said circuit, an operating circuit for said second relay controlled by operation of said first relay, and another operating circuit for said second relay completed as a result of telephonic association of said subscribers set with said line independent of said first relay.

3. A telephone system comprising a line, a signal associated with said line, a subscribers set for telephonic association with said line, a source of direct current, arelay operable to connect said source of current with said line, an operating circuit for said relay, a second relay having a plurality of windings and operable to open said circuit, an operating circuit for said second relay including one of said windings and controlled by operation of said first relay, and another operating circuit for said relay including another of said windings and completed as a result of telephonic association of said subscribers set with said line independent of said first relay.

4. A telephone system comprising a line, a signal associated with said line, a subscribers set for telephonic association with said line, a source of direct current, a relay operable to connect said source of current with said line, an operating circuit for said relay, a second relay serving as an impedance means during telephonic association of said set with said line and operable to open said circuit, an operating circuit for said second relay controlled by operation of said first relay, and another operating circuit for said second relay completed as a result of telephonic association of said set with said line.

5. A telephone system comprising a line, a signal associated with said line, a subscribers set, means to associate said set with said line, a source of direct current, a relay serving when operated to connect said source of current with said line to operate said signal, an operating circuit for said relay, a second relay operable to open said circuit, an operating circuit for said second relay controlled by operation of said first relay, and another operating circuit for said relay completed as a result of establishment of telephonic association of said set with said line.

In witness whereof I hereunto subscribe.

my name this 18th day of March, A. D. 1918.

CHARLES W. KECKLER.

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