US1484963A - Telephone-exchange system - Google Patents

Description

Feb. 26, 1924.- 1,484,963

A. RAYNSFORD TELEPHONE EXCHANGE SYS TEM Filed Sept. 14. 1920 2 Sheets-Sheet 1 Fig.

POLAR/Z50 A. RAYNSFORD TELEPHONE EXCHANGE SYSTEM v Filed Sept. 14 1920 2 Sheets-5heet 2 Ari/2w Faynsford Patented Feb. 26, 1924.

PATENT OFFIQE.

UNETED STATES ARTHUR RAYNSFORD, OF NEW YORK, N. Y., ASSIGNOR TO WESTERN ELECTRIC COM- PANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE-EXCHAN GE SYSTEM.

Application filed September 14, 1920. Serial No. 410,311.

To all whom it may concern:

Be it known that I, ARTHUR RAYNSFORD,

a citizen of the United States of America,

residing at New York, in the county of New York 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 more particularly to such systems in which connections between the subscribers stations are established partly by means of automatic switching apparatus and partly with the aid of an operator. More specifically, the invention relates to trunk circuits for use at a call indicator operators position. wherein link circuits equipped with automatic ringing and means for actuating coin collect or message register equipment terminate, to extend calls to a second operators position such as a rural position or the like.

It is a well-known practice to arrange link circuits so that a source of automatic ringing current is disconnected when a called subscriber, with whose station the link circuit may be connected, responds. It is also well known to utilize the closure of a loop 30 at the called subscribers station when the receiver is removed from the switch hook thereat, to operate a current reversing relay in the link circuit which, in turn, causes the actuation of a coin collect or message register device at the station of a calling subscriber. If the call indicator operator, at whose position subscribers lines terminate, is also provided with trunk circuits, extending to a. second operators position such as a rural position, it is obvious that it is not desirable to operate the current reversing relay in the link circuit when the rural operator responds, since this would cause the operation of the coin collect or message register device at the calling subscribers station before the called subscriber had actually responded.

It is, therefore, an object of the present invention toprovide means whereby, when the link circuit at the first operators or call indicator operators position is connected with the trunk circuit extending to the rural or second operators position, ringing current is automatically tripped, a signal at the second or rural o-perators position is actuated, and an audible ring-back signal is connected to the trunk for the purpose of informing the calling subscriber that the connection is progressing.

Another object of the invention is to provide complete super-vision for the operators at the first and second positions in handling traiiic of this nature.

A. further object of the invention consists in the provision of means in a system of this character whereby, if the operator at the first position disconnects before the operator at the second position disconnects, a busy potential will be placed upon the jack at the first operators position and the multiples thereof, until the operator at the second position disconnects.

One of the features of the invention consists in the provision of means, in a trunk circuit extending from a first to a second operators position, for disconnecting a source of automatic ringing current from a link circuit, when the link circuit is connected to the trunk circuit, for lighting a lamp at the distant end of the trunk and for connecting an audible ring-back signal to the link circuit.

A further feature of the invention consists in the provision of manually controlled means at the second operators position for rendering a normally conductively divided trunk circuit continuous for the purpose of actuating a current reversing relay in the connected link circuit and for providing supervision for the operator at the second position.

It is thought that the invention will best be understood from the following detailed description, reference being had to the accompanying drawings.

In the drawings, Fig. 1 shows a subscribers set and indicates diagrammatically, a non-numerical switch, a first and second selector by means of which a desired office may be selected, a repeater for repeating impulses over a two-wire trunk to a selected manual ofiice and a link circuit at the manual ofiice for use in extending calls from a station such as 1, to subscribers lines and other trunk circuits leading to other positions. The link circuit L, which terminates in a plug 78, is one of a plurality of link circuits which are located at the call indicator trunk leading to the desired oflice.

number indicating device. together with switching mechanism for operating such device. Theindicating device and switching mechanism are not shown being simply indicated by the rectangle 1, since they form no part of the present invention, a complete description thereof being given in the patentof Lundell-Van Amstel, No. 1,456,508, issued May 29, 1923. v

Fig. 2 of the drawings shows a trunk circuit T which extends from the call indicator operators position to the rural position. At the rural position a cord circuit 13 is provided (a portion only of which is shown), for the purpose of extending calls through the trunk circuit T to subscribers stations (not shown) terminating at the rural operators position. The trunk circuit T comprises a pair of talking conductors and a non-talking conductor. The talking conductors of the trunk circuit T are normally discontinuous one of the talking conductors being normally open and the other of the talking conductors being normally inductively united by means of the condenser 110. Fig. 2 also shows the station of an or-.

dinary subscribefis set 101 terminating in a jack 102 at the call indicator operators position.

Assuming first, that the subscriber at station 1 desires connection with a manual subscriber, the operation will be as follows: lVhen the calling subscriber removes his receiver from the hook, a circuit will be completed to cause the operation of a line switch diagrammatically indicated at '2, which will connect the calling lineto a first selector Whose brushes are shown at 3. He will then operate his dial to send a number of impulses whereupon the selector will be operated to select a trunk in a certain level of the contact bank. The subscriber will thensend another set of impulses to operate the selector whose brushes are'indicated at 42 which will then operate to select an idle trunk in a level of its contact bank. The calling subscriber has now selected apx idle description of the operation of the line switch and first and second selector switches, or oflice selectors, as they may be termed, has not been given since they may be of any of a number of types of step-by-step switches well-known in the art.

As soon as selector 42 has seized a trunk, a circuit is completed from grounded battery, right-hand winding of relay 4, inner right-hand armature and back contact of relay 5, upper left hand winding of repeating coil 43, over the upper side of the line, through the subscribers substation apparatus, over the lower side of the line, lower left hand winding of repeating coil 43, inner left hand armature and back contact of relay 5, and the left-hand winding of peating coil 43, right-hand armature and front contact of relay 4, lower right-hand winding of repeating coil 43, winding of polarized relay 5, trunk conductor 11, lower left-hand winding of repeating coil 9, lefthand normal contacts of relay 8, and the left-hand winding of relay '7 to ground. Polarized relay 5 is not energized at this time since the direction of flow of current therethrough is such as not to cause its energization. .Relay 7, is however, energized in this circuit and opens a circuit to impulse conductor 91-, but completes a circuit at its alternate contact, which causes the operation of apparatus (not shown) necessary for the reception of the succeedingimpulses. Under the control of relay 7, the apparatus, for receiving the succeedingimpulses from the impulse sender, is actuated, whereupon an assignment lamp (not shown) is lighted to inform the operator that the apparatus has been set. v

The operator upon observing the lighting ofthe assignment lamp, depresses an assigment key (not shown) thus completing circuits for the number indicating device (not shown), which indicates to the operator the number desired.- The depression of the assignment key causes certain relays associated with the call indicator apparatus to be actuated, which in turn causethe relays 69 and 13 to be actuated in parallel over a circuit including conductor 70.

Assuming first thatthe number appear- 7 ing upon the call indicating device represents the number of asubscribers line terminating ina jack at the call indicator operators position such as 101 shown in Fig. 2 of the drawings, the operator after noting the number will insert plug 78 into jack 102 of the desired line. A circuit is then completed from grounded battery, lamp 80, winding of relay 67, left-hand armature and back contact of relay 81, sleeves of plug 78 and jack 102 and Winding of cutiofl' relay 103 toground. Lamp 80 is lighted and relays 67 and 103 are energized in this circuit. The energization of relay 103 removes the called subscribers control of his line relay in the well-knownmanner. Energization of relay 67 completes a circuit for the application of ringing current. This circuit is as follows; grounded battery, winding ofrelay83, left-hand armature and back contact of relay 84, armature and back contact of relay 85, outer right-hand armature and front contact of relay 13 now energized in the manner described for the like numbered relay 13, in the above mentioned disclosure, lowermost armature and front contact of relay 67, and winding of relay 67 to ground as described. The low resistance of relay 83 shunts out lamp 80 and this lamp is extinguished. The energization of relay 83 completes a circuit from a source of ringing current 90, Winding of relay 85, lower armature and front contact of relay 83, rings of plug 78 and jack 102 over the loop of the called substation-101, tips of jack 102 and plug 7 8, upper armature and front contact ofrelay 67 and'upper armature and front contact of relay 83 to ground. In response to the completion of this circuit, the bell at the called station is caused to ring. When the called subscriber answers, relay 85 operates and in so doing removes the shunt from about the winding of relay 84. Relay 84 is then energized and locks up through its left-hand armature and front contact. Battery at the left-hand armature and front contact of relay 84 serves to shunt down relay 83. As soon as relay 83 deenergizes, the talking circuit is completed and the s'ubscribersmay converse.

As soon as relay 83 is deenergized current flow from the battery in repeating coil 9 energizes a supervisory relay 87 and since relay 84 isalso energized, a circuit is completed from grounded battery, winding of relay 8, armature and front contact of relay 87, right-hand armature and front contact of relay 84 to ground. Relay 8 is energized in this circuit and reverses the direction of current flow in the incoming end of the link circuit L. This reversal of current operates polarized relay 5 of the re peater R. The operation of relay 5 reverses the direction of current flow in the calling subscribers line for the purpose of operating a coin collect or message register device in a manner well-known in the art.

As soon as relay 67 was energized the apparatus necessary for actuating the number indicating device was restored to normal position and made available for the use. with other link circuits such as L in the manner described in the heretofore mentioned disclosure.

When the conversation is completed and the calling subscriber has replaced his receiver, line relay 7 is deenergized as a result of the deenergization of line relay 4. Direct ground on the back contact of the armature of relay 7 shunts down relay 69 and releases relay 69 which was previously energized in the manner described for the like numbered relay 69, in the heretofore mentioned disclosure, causing in turn the release of relay 13. The circuit of relay 84 is therefore broken at the outer right-hand armature and front contact of relay 13 and the shunt is removed from about lamp 80, causing this lamp to burn steadily as a disconnect signal. The operator thereupon removes the plug 7 8 from jack 102. The link circuit L is then free for use with other connections.

.It will next be assumed that a number appears upon the call indicator device at the call indicator operators position, which is of such a character as to indicate that a connection with a rural subscriber is desired. The call indicator operator thereupon inserts plug 78 of the link circuit L into jack 104 of the trunk circuit T leading to the rural operators position, whereupon relays 105 and 67 are energized and lamp 80 is lighted over a path extending from grounded battery, lamp 80, winding of relay 67, back contact and left-hand armature of relay 81, sleeves of plug 78 and jack 104, Winding and left-hand normal contacts of relay 105, and back contact and outer left-hand armature of relay 117 to ground. Relay 105 in attracting its left hand armature locks up to battery on the sleeve of plug 78. Relay 67 in operating completes a circuit for the application of ringing current. This circuit is as follows: grounded battery, winding of relay 83, left hand armature and back contact of relay 84, armature and back contact of relay 85, outer right-hand armature and front contact of relay l3, lowermost armature and front contact of relay 67, winding of relay 67, back contact and left-hand armature of relay 81, sleeves of plug 78 and jack 104, winding of relay 105, and left-hand alternate contacts of relay 105 to ground. The low resistance of relay 83 shunts out lamp 80 and this lamp is extinguished. The energization of relay 83 completes a circuit from the source of ringing current 90, winding of relay 85, lower armature and front contact of relay 83, ring contacts of plug 78 and jack 104, back contact and inner left-hand armature of relay 112 and resistance 113 to grounded battery. Relay 85 immediately energizes, and in so doing removes the shunt from about the winding of relay 84. Relay 84 is then energized and locks up through its left hand armature and front contact. Battery at the left-hand armature and front contact of relay 84 operates to shunt down relay 83. Relay 83 in retracting its armatures renders the outgoing end of the link circuit L continuous.

As heretofore described relay 105 was operated and locked up as soon as plug 78 was inserted into jack 104. Relay 105 in attracting its outer right-hand armature completes a circuit through the right-hand ar- 106, inner right-hand armature and front contact of relay 105, back contact and outer left-hand armature of relay 112, condenser 109, tips of jack 104 and plug 78, upper alternate contacts of relay 67, upper normal contacts of relay 83 and upper right-hand winding of repeating coil 9 to ground. The tone passing through the upper right-hand winding of repeating coil 9 induces a corresponding tone in the left-hand winding of repeating coil 9, which passes over the talking conductors to the calling subscriber at station 1 in a manner well-known.

The operator at the rural position noting the trunk signal 114, inserts plug 119 ofthe cord circuit T, whereupon relay 117 of the trunk circuit T is operated. The path for the energization of relay 117 extends from ground, throughthe winding of relay 117, sleeves of jack 116 and plug 119, resistance 120, and supervisory lamp 121 to grounded battery. Relay 117, in operating, connects battery through resistance 118, front contact and right-hand armature of relay 117 to conductor 140, so that in case the call indicator operator disconnects before the rural operator and relay 105 releases, a busy test will be placed on the sleeve of the trunk jack 104 and the multiples thereof. Relay 117 in operating also completes a circuit for relay 112 over a path extending from ground, outer left-hand armature and front contact of relay 117, and winding of relay 112 to grounded battery. Relay 112 in attracting its right-hand armature locks up to ground at the outer right-hand armature and front contact of relay 105 and opens the circuit for trunk signal 114, thereby extinguishing said signal. Relay 112 in operating also disconnects the tone from the source 107, from the trunk circuit T and renders the tip talking conductor of the trunk circuit T continuous. At the inner left-hand armature and back contact of relay 112, the battery, through resistance 113 for tripping the ringing current, is disconnected from the trunk circuit T.

As soon as relay 112 attracts its outer left-hand armature, supervisory relay 122 of the cord circuit B is operated over a path extending from ground, upper righthand winding of repeating coil 9, upper normal contacts of relay 83, upper alternate jack 104, resistance 108 outer left-hand armature and front contact of relay 112 rings of jack 116 and plug 119 winding of relay 122 and lower left-hand winding of repeating coil 123 to grounded battery. Relay 122 in operating shunts out lamp 121 in the well known manner and provides supervision for the answering end of the cord circuit B. When relay 122 is operated, relay 117 is held energized by battery through resistance 130 and the contact'sof relay 122.

The operator may now actuate the listening key 141 for the purpose of ascertaining the number desired and upon being informed of such number inserts the calling plug of the cord circuit B (not shown) into the jack of a line (not shown) and completes the call in the well-known manner whereupon supervisory lamp125 lights.

ing station by actuating key K of the trunk circuit T. Actuation of key K completes a circuit for relay 115, which relay in operating locks up over a path extending from grounded battery, winding and right-hand armature and front contact of relay 115, front contact and iinner {lefthand armature of relay 117 to ground. The relay 115 in attracting its left-hand armature bridges resistance 111 around condenser 110.

Supervisory relay 87 of the link circuit L is then energized over a path extending from grounded battery, lower right-hand winding of repeating coil 9, Winding of relay 87, lower normal contacts of relay 88, rings of plug 78 and jack 104, resistance 111, front contact and left-hand armature of relay 115, tips of jack 116 and plug 119' and upper left-hand winding of repeating coil 128 to ground. Relay 87 in operating completes a circuit for relay 8 over a path extending from grounded battery, winding of relay 8, front contact. and armature of relay 87, righthand armature and front contact of relay 84 to ground. Relay 8 in attracting its armatures reverses the direction of current How in the incoming end of the link circuit L. This reversal of current oggrates polarized relay 5 of the repeater The operation of relay 5 reverses the direction of current flow in the calling subscribers line for the purpose of operating a coin collect device or a message register device in a manner well-known in the art.

the calling subscriber has replaced his receiver, line relay 7 is deenergized as a result of the deenergization of line relay 4. Direct ground on the back contactof the armature of relay 7, causes the release of" relay 13 in the manner described in the heretofore mentioned disclosure. The circuit of relay 84 is thereupon interrupted at the outer right-hand contact and armature of relay 13 and the shunt is removed from lamp causing this lamp to burn steadily as a disconnect signal. The operator may then remove plug 78 from jack 104 whereupon the link circuit L is free for use with other connections.

\Vhen the called subscriber replaces the receiver upon the switchhook, supervisory relay 124 of the cord circuit B deenergizes thereby lighting supervisory lamp 125 which serves as a disconnect signal.

If the call indicator operator disconnects first the bridge across the link circuit at the call indicator position is opened thereby causing the deenergization'o-f supervisory relay 122 at the rural operators position. Itelay 122 in deenergizing removes the shunt from supervisory lamp 121, causing this lamp to light, which indicates to the rural operator that the operator at the call indicator position has disconnected. Removal of the plug 7 8 at the call indicator positlon, from the jack 104 also causes the release of sleeve relay 105 associated with the trunk circuit T. Closure of the left-hand normal contacts of relay 105 connects battery, present on conductor 140, to the sleeve of jack 104 and multiples thereof, thereby rendering the trunk busy. When the rural operator disconnects, relay 117 releases. Relay 1 17 in retracting its left-hand armatures, opens the circuits for relays 112 and 115 and in retracting its right-hand armature removes battery from conductor 140, thereby restoring the trunk circuit T to normal.

If the rural operator disconnects first, relay 117 releases, thereby opening the locking circuit for relay 115. When the call indicator operator disconnects, relay 105 releases causing in turn the release of relay 112, whereupon the trunk circuit T is restored to normal.

What is claimed is:

1. In a telephone system, an incoming line, current reversing means associated therewith, a trunk circuit, means associated with said incoming line for applying ringing current to said trunk circuit, a signal for said trunk circuit, a source of tone, means effective upon the connection of the incoming line to the trunk circuit to trip said ringing current without operating said current reversing means, and means in said trunk circuit also effective upon the connection of the incoming line to the trunk circuit to apply tone from said source to said incoming line and to. actuate said signal.

2. In a telephone system, an incoming line, current reversing means associated therewith, a trunk circuit, means associated with said incoming line for applying ringing current to said trunk circuit, a signa for said trunk circuit, a source of tone, means operative in response to the connection of the incoming line to the trunk circuit to trip the ringing current without operating said current reversing means, and a relay in said trunk circuit operative in response to the connection of the incoming line to said trunk circuit to apply tone from said source to said incoming line to actuate said signal.

3. In a telephone exchange system, an in coming line, an outgoing line including a pair of talking conductors and a sleeve conductor, means for establishing a connection between said lines, a signaling circuit completed upon the establishment of said connection, means including a source of current normally connected to one of the talking conductors of said outgoing line for rendering said signaling circuit inefiective upon the establishment of said connection, a source of tone supply, a signal, and a single relay in the sleeve conductor of said outgoing line operated when said connection is established for connecting said source of tone supply to said incoming line and for operating said signal.

4. In a telephone system, a subscribers line, a trunk circuit, a signal, a source of tone associated with said trunk circuit, an incoming line, means for establishing a connection between said incoming line and said subscribers line or between said incoming line and said trunk circuit, current reversing means associated with said incoming line, means associated with said incoming line for applying ringing current to said trunk line, means for tripping said ringing current and operating said current reversing means when said incoming line is connccted to said subscribers line, and means for tripping said ringing current, for connecting said source of tone to said incoming line, for preventing the operation of said current reversing means and for lighting said signal in response to the connection of said incoming line to said trunk circuit.

5. In a telephone exchange system, a trunk circuit extending from a first to a second operators position, a condenser normally dividing the trunk circuit into two sections, a link circuit terminating at said first position, a signal, a source of tone supply, a current reversing relay associated with said link circuit, a supervisory relay associated with said link circuit, a source of ringing current associated with said link circuit adapted to be connected to said link circuit when said link circuit is taken for use, means responsive to the connection of IUD with said trunk circuit for disconnecting said source of tone supply from said trunk circuit and for extinguishing said signal,

7 and operator controlled means for providing a path around said condenser so as to operate said supervisory relay to operate said current reversing relay.

6. In a telephone exchange system, a first position and a second position, a trunk circuit extending between said positions and terminating at each position in a jack, said circuit comprising a pair of talking conductors and a non-talking conductor, a link circuit at each of said positions, a supervisory signal for each of said link circuits, a signal for the trunk circuit at said second position, a relay connected to the sleeve of the jackat the first position energized when the link and trunk circuits are connected at the first position for operating said trunk signal, means for extinguishing said signal when the link circuit at the second position is connected to the trunk circuit, and means including said relay for rendering said ack at said first position busy if the operator at the first position disconnects first.

7 In a telephone exchange system, a first operators position,a second operators position. a trunk circuit extending between said positions, said trunk circuit having a pair of talking conductors and a non-talking, conductor, a signal at said second position, a link circuit at each of said positions connected to said trunk, a relay at each of said positions connected to the non-talking conductor of said trunk, and a circuit completed through contacts of said relays for rendering the trunk busy if the operator at the first position disconnects before theop erator at the second position disconnects.

8. In a telephone exchange system, a first operators position, a second operators position, a subscribers line terminating at said first position, a trunk line extending between said positions, a signal at said second posi-- tion for said trunk line, an incoming link circuit terminating atsaid first position for extending calls thereover to said subscribers line or over said trunk line, a current reversing relay therein, means for operating said relay when a called subscriber answers, a cord circuit at said second operators position, a supervisory relay therein, means for actuating said signal when said link circuit is connected to said trunk line, means for extinguishing said signal and actuating said supervisory relay when said cord circuit is connected to said trunk line, and operator controlled means for actuating said current reversing relay.

In witness whereof, I hereunto subscribe my name this 11th day of September A. D., 1920.

ARTHUR BAYNSFORD.

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