US1325871A - Chables w - Google Patents

Description

C. W. KECKLER. TELEPHONE SYSTEM; APPLICATION FILED MAY24. 1911.

1,325,871. Patented Dec. 23,1919.

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by Affy.

UNITED STATES PATENT OFFICE.

CHARLES V. KECKLER, F NEWARK, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE SYSTEM.

assen.

Specification of Letters Patent.

Patented Dec. 23, 1919.

Application filed May 24, 1917. Serial No. 170,601.

To all who m, itmay concern:

Be it known that I, CHARLES W. KEOKLER, a citizen of the United States, residing at Newark, in the county of Essex and State of New Jersey, have invented certain new tems and more particularly to intercommuni- Bill eating telephone systems.

The principal object of the invention is to provide a simple and ellicient arrangement of circuits and apparatus to effect uniform communication between the different stations of the system, and to this end, electromagnetic means are provided at each station to control the connection of the home line of a calling station with the line of the called station; certain windings of the electromagnetic means at connected stations also serving as impedance or retardation coils through which talking current is supplied directly to each of two or more connected lines.

A further object is to enable another station to be brought into telephonic connection with two or more stations already connected but to audibly indicate to the stations already connected that an attempt is being made to connect in another station. To accomplish this, the relay of the last party called on being energized and signaling another station, connects the line of the called station in the telephonic circuit of the parties already connected while the transmitter of the called station is bridged across the line of that station during signaling and an audible signal arranged in proximity thereto which enables all the stations previously connected to hear the sound produced by the signal at the called station.

This and other features of the invention may be more readily understood by reference to the accompanying drawing, wherein the invention is shown as applied to an i11- tercominunicating telephone system. Three stations, each having lines extending to the other stations, are shown, although obviously a greater number of stations can be furnished if desired. The apparatus and circuits of stations A and B are identical and while the apparatus at station C is identical with the other stations, the circuit differs therefrom by controlling the connection of the transmitter and receiver across the line of that station through the operation of its hook-switch, whereas at stations A and B the transmitter and receiver are permanently brldged across their respective lines for a reason to be hereinafter described.

In making a call, the calling party will remove his receiver, thus supplying talking batter to his set through two windings of a marginal relay (not ope ated at this time), these two windings serving as impedance or retardation coils for the calling line. The calling button of the desired station is then depressed and in its lowermost position supplies ringing battery through another winding of the relay which cooperates with the other two windings previously energized to pull up its armature. Ringing battery is also supplied to the hell or other signal at the called station and as the calling station is connected to the line called upon the relay pulling up, the calling party can hear the operation of the signal at the called station provided the transmitter at the called stationis bridged across its home line during signaling; as is the case with stations A and B shown.

The party at the called station would remove his receiver from the hook on answering and thereby supply talking battery directly to the called line through two of the windings of the relay at the calledstation.

This relay being marginal does not operate under these conditions but the energized windings serve as retardation coils in supplying talking battery to the called station in the same way as the relay at the calling station. On completion of conversation, the parties hang up and the talking windings of the relays are deenergized, whereupon the armature of the relay at the calling station falls back, thereby disconnecting the set from the previously connected line, although the calling button has not been released from its intermediate position. On making another call the button first operated is automatically released by depression of another calling button in the usual manner.

T 0 illustrate the operation more in detail, assume that station A wishes to call station B. Receiver at A would first be removed, thereby supplying current from a common talking battery 5 over a circuit extending from battery 5, conductors 6 and 7 righthand winding ofmarginal relay8 individual to station A, conductor 9, switch contact 10 in upper position, conductor 11, transmitter'and. receiver of station A, conductor 12, switchhook 4 and upper contact, conductor 13, middle winding of relay 8 (wound in series aiding relation to the right-hand winding thereof) and conductors 14 and 6 to the other side of battery 5. The relay 8 is so margined that it will not pull up except on energization of all three windings WlllCll increases the effective ampere turns of the relay windings to effect its operation. After being. pulled up, however, this relay w1ll be maintained in operative position so long as the middle and right-hand windings remain energized.-

:These last mentioned vwindings perform the function of retardation coils in supply ing talking battery to the set with which they are connected. This arrangement is important as it supplies each station with talking battery. directly through certain windings of the relay individual thereto, as soon as the receiver is removed from its hook so that connected stations are each directly supplied with talking current, thus improving communication between the stations and greatly increasing the transmitting efliciency.

1 After removing his receiver the party at A will depress a calling key K individual tostation B. This key in common with the other calling keys K, K and K is designed to be depressed as far as it will go in calling so as to contact with the lowermost spring of the key and to engage the center spring thereof with a bus bar 15. The keys remain in the lowermost position only so long as they are manually held there by the person calling, and return to an intermediate position in which they are held by the usual locking plate 16 as soon as pressure on the calling button is relieved. position only the first and second and third and fourth springs, respectively, of the key are engaged. The operation of any key in calling releases any other key which may have remained in locked position, although as hereinafter explained, it is not necessary that keys which may be in locked position at a called station be released to obtain connection with the calling line or to prevent interference by other parties; although generally necessary heretofore in systems of this kind.

The bus bar 15 is connected to one side of a ringing battery 17 by a conductor 18, extending to one wire 19 of the common ringing battery wires 19 and 19 and on full depression of the key K a circuit is completed to. operate a signal 20 at station B; this. circuit extending from battery 17 conductors 19 and 18, bar 15, third spring of key K conductor 21, line wire 2, conductor 22, hook switch 23 and lower contact, conductor 24, armature and winding of sig- In intermediate nal 20, conductor 25 and lead wire 19 to the other side of ringing battery. The signal 20 interrupts its own circuit and continues to operate only so long as the key K is held in its fully depressed position.

A circuit is also closed at this time to energize the left-hand winding of the relay 8 to cooperate with the other two windings previously energized to pull up the armature thereof. This circuit extends from signaling battery 17, conductors 19 and 18, bus bar 15, third spring of key K and fourth and fifth springs thereof, conductors 27 and 28, left-hand winding of relay 8, conductors 29 and 19 to the other side of battery. The operation of the relay 8 serves to connect the set at station A with the line wires 2, 2 of station B and inasmuch as the telephone set of station B is bridged across these line wires during signaling, by using an audible signal 20 and locating it in proximity with the transmitter of the set. the calling party at A will hear the sound of the signal 20 reproduced by the transmitter at station B and will know that the line is idle and that the signal is being received, whereas if the line is busy, the signal will not be operated and the calling party hearing nothing will know the called line is busy. Assuming station B to be idle, the circuit to render the operation of the signal 20 audible to station A is in parallel with the talking circuit of station A. previously traced and commences at conductor 11, thence by conductor 30 to outer arm and front contact of relay 8 (now energized), conductors 31 and 32, second and first springs of key K conductor 33, line wire 2, conductor 3-1, transmitter and receiver of the set at station B to conductors 22 and 2, conductor 21, third and fourth springs of key K conductors 36 and 37, inner armature and front contact of relay 8, which armature is connected to conductor 12 and completes the parallel circuit.

This feature is of considerable advantawc, as hearing the actual sound given 011' y the signal at the called station gives a distinctive indication not liable to be confused with other signals, which has proved an objectionable feature where tone signals have been used.

If this feature of the invention is not desired for any reason, it is only necessary to arrange the transmitter so that it is not in circuit while its signal is being operated. This may be done by arranging the switchhook to close the circuit thereto only when the hook is up and the signal disconnected, and the telephone set at station C illustrates such an arrangement. The same result may also be obtained by arranging the audible signal at station C in such a way that the sound therefrom will not actuate the transmitter orby using a visual rather than an audible signal.

The party at station B on hearing his signal would respond by removing his receiver from the hook, whereupon as previously explained for station A, talking battery will be supplied directly to the telephone set of station B through the middle and right-hand windings of relay 38. This circuit extends from battery 5, conductors 6 and 89, right-hand winding oi relay 38, conductor 40, upper position of contact 41, conductor 34:, transmitter and receiver of station B, conductor 22, switchhook 23 and upper contact (now closed), conductor 42, middle winding of relay 38, conductors 43 and 6, to the other side of battery. Relay 38 being marginal will not pull up when station B is the called station as previously explained but the middle and right-hand windings nevertheless serve as retardation coils in supplying talking battery thereto, thus providing both of the connected stations directly'with talking battery through their respective relays 8 and 38. This provides better transmission than where but one of the stations is supplied directly with talking battery and the other stations connected therewith are supplied indirectly through the first station as has been the general practice in intercommunicating systems heretofore.

It will be observed that the connection of station B is independent of the position of any of the calling keys thereat, and the line to any station whose calling key might be in locked position at station B would not be connected, as the only connecting circuit is through the conductors A l and i5 and the front contacts and armatures of the relay 38 which is not pulled up while station B is serving as a called station.

For the purpose of illustrating how two connected stations can bring another station in telephonic connection with the connected lines and at the sam time give an audible indication to those already connected that such an attempt is being made, assume that station A has called station C and that the two stations are in telephonic communication. Assume that the party at station C desires to enable the party at station B to hear or oin in the conversation either with or without the consent of the party at station A. Station C being the called line, the relay 4:8 thereat would not be pulled up although the middle and right-hand windings would be energized. Therefore, the full depression of the key K individual to station B, at station C would energize the left-hand winding of the relay 48, which would thereupon pull up, as previously explained for the relay 8, at station A (C now acting as a calling station). The relay 48 pulling up and cooperating with the K would connect the telephone set at station 0 with the lines wires 2 and 2 of station B "LEV and station A being already connected with station C would also be connected with the line wires of station B through the apparatus of station 0. At the same time the circuit energizing the left-hand winding of the relay 48 is closed. The signaling circuit to station B is also closed to operate the audible signal 20, this circuit being similar to that described when station A signaled station B.

Inasmuch as the transmitter of the set at B is bridged across its line during signaling and the signal 20 located in proximity thereto, the operation oi the signal would be audible to station C and also to any other stations which are in telephonic communication with station C when the latter calls station B. In this way, such other stations would be apprised of the fact that an attempt was being made to bring in a party at another station and enable them to take appropriate action in the event they did not wish the inclusion of the additional party for any reason.

The party at station B in responding would remove his receiver from the hook in the usual manner and supply talking current directly to his set through the middle and right hand windings of the relay 38 as previously explained. Stations A and C were already in telephonic communication at the time station C called station B, and as a similar connection is provided between stations C and B, stations A and B are brought into telephonic communication through the apparatus at station C so that all three parties can converse freely together. Disconnection would be effected by the hanging up of the receivers in the usual manner and result in the deenergization of the relays 8 and-4c8 in the manner previously described, to restore the apparatus to normal position.

What is claimed is:

1. In a telephone system, a plurality of line circuits, a telephone set associated with each line circuit, a relay individual to each of said telephone sets and having a winding, switching means individual to each of said telephone sets operable to effect the operation of one of said relays to connect two of said line circuits together, and a common source of talking current for said telephone system; said winding of each of the relays of connected line circuits being interposed between said source of current and its respective telephone set and serving as i1npedance means for talking current supplied to the telephone set individual thereto during such connection.

2. In a telephone system, a plurality of line circuits, a telephone set including a receiver and hook therefor associated with each line circuit, a relay individual to each telephone set and having a winding, switching means individual to each of said telephone sets operable to effect the operation of one of said relays to connect two of said line circuits together, a common source of talking current for said telephone system, m ans individual to each telephone set to supply current through its respective relay to such set directly on removal of the receiver of the set from its hook; said relays being interposed between said source of current and its respective telephone set and serving as an impedance means for talking current supplied to the telephone set individual thereto.

3. In a telephone system, a plurality of line circuits, a telephone set including a receiver and a hook associated with each of said line circuits, a relay individual to each of said telephone sets to connect two of said line circuits together, said relay having a plurality of winnings, a source of current for said telephone system, means individual toeach set to supply current to its respective set through a winding of the relay indi vidual thereto directly on the removal of itsreceivcr from its hook, switching means for each of said line circuits adapted to sup ply current through another or said relay windings to actuate said relay; the first mentioned of said windings serving as im pedance means for talking current supplied to its respective set.

l. In a telephone system, a plurality of line circuits, a telephone set including are ceiver and hook associated with each of said line circuits, a marginal relay having a plurality of windings associated with each of said telephone sets to connect two of said line circuits together, a source of current for said system, means individualto each set to control the supply of current to said set through certain oi said relay windings on removal of the receiver from its hook, said certain of said relay windings serving as an impedance means, and switching means associated with each of said line circuits adapted to supply current to certain other of said windings to cooperate with the remaining windings to operate said relay, energization of said impedance windings serving to maintain said relay in operative position.

5. In a telephone system, a plurality of line circuits, a telephone set including a receiver associated with each of said line circuits, a relay having a plurality of windings and individual to each of said telephone sets to connect two of said lines together, a receiver switch for each of said sets to supply talking battery to its set directly on removal of the receiver through one or more of said relay windings, said one or more windings serving as impedance means therefor, means at each of said sets to supply signaling current through one winding of the relay of the calling set to operate the signal at a called set, said relay requiring energization of the winding traversed by signaling current in order to operate and being maintained in operative position by energization of said one or more windings traversed by talking current.

6. In a telephone system, a plurality of line circuits, a plurality of telephone sets, a relay having a winding and individual to each set to connect its associated set with one of the line circuits, means for supplying current to one of the telephone sets through a winding 01" its respective relay without operating such relay, and means to increase the effective ampere turns of such relay to operate such relay to connect its respective set with one of the line circuits.

7. In a telephone system, a plurality of line circuits, a telephone set including a transmitter associated with each line circuit, means to telephonically connect two of said line circuits together, means associated with one of said connected line circuits to telephonically connect another line circuit to those already connected, an audible signal associated with said other line circuit, means operated incident to connecting said other line circuit to line circuits previously connected to operate said signal, and connections operatively associating the transmitter of the set of said other line circuit with such circuit during signaling of such set to render the sound produced by said signal audible to the sets oi said previously connected line circuits through the medium of such transmitter.

8. In a telephone system, a plurality of line circuits, a telephone set comprising a receiver and transmitter associated. with each line circuit, means associated with each of said line circuits to connect it to another line circuit, said means being operable only when the line circuit is the calling line, an audible signal individual to each of said telephone sets and arranged in proximity thereto, and means operated incident to the connection of another line circuit to operate said signal, the transmitter of the set signaled being connected across its line circuit during signaling, whereby the sound produced by said signal is communicated to the set of the line calling and also to any other sets which are in telephonic connection with a line circuit calling another line circuit.

In witness whereof, I hereunto subscribe my name this 22nd day of May A. D., 1917.

CHARLES W. KECKLER.

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