US1821193A - Telephone system - Google Patents

Description

Filed May 5, 1930 2 Sheets-Sheet 1 l\ my,

INVENTOR WILLIAM J. VlNCENT ATTORNY Sept. 1, 1931. w. J. VINCENT 1,321,193

TELEPHONE SYSTEM Filed May 5, 1930 2 Sheets-Sheet 2 OPERATE SLOW TO TO IN TERRUPTER INVENTOR WILLIAM J. VINCENT BYA ATTORNEY Patented Sept. 1, 1931 UNITED STATES PATENT orrice WILLIAM J. VINCENT, OF ROCHES ER, NEW YORK, AssIGNoIt'ro THE ROCHESTER TELEPHONE CORPORATION, OF nocr'rnsr'nn, NEW YonK, A oonronerron or rvnw YORK TELEPHONE SYSTEM Application filed May 5, 1930. Serial No. 450,047.

This invention relates to telephone systems and more particularly to manual telephone systems.

In the past it has been the practice in manual telephone systems, especially in the case where the busy called line terminated in the same exchange as the calling telephone line, to provide at least one busyback jack into which the operator plugged the calling end of a cord circuit connected to a calling telephone line which desired connection to a called line that tested busy. As long as this cord circuit was connected to such a busyback jack, a source of the busy tone current was extended to the calling telephone line which caused a distinctive signal in the receiver of the calling telephone line to indicate to the subscriber there-at that the wanted line was busy; In such a system it was necessary for the operator to insert the calling plug of such a cord circuit into a busyback jack and subsequently to .remove the plug from that jack when it was desired to terminate the busyback signal.- These operations required a considerable amount of time which otherwise could be used'in establishing useful connections.

In accordance with the present invention the need for busyback jacks has been obviated by providing a busyback key and associated equipment common to all of the cord circuits 0]": an operators position so that as soon as a called line tests busy it is merely necessary for the operator to depress this key after which the busyback signal is transmitted to the callin telephone line until the subscriber aba-ndbns the call or initiates a recall. A further feature of the invention includes the use of the ringing relay of a cord circuit to control the application of the busyback tone tothe calling tele-' phone line. These and other features will appear from the detailed description and an pended claims.

For a clearer understanding of the invention reference is made to the drawings in represented one of a plurality of telephone lines which may be a calling line while thei'ji center portion of this figure and aportion of Fig. 2 abovethe brokenline represent equipment individual to a cord circuitlof which there may be several located at each operators position. In the upper right-L55 hand corner of Fig. l there'isrepresented a called telephone line while the portion of Fi 2 below the broken line represents the equipment common to the cord circuits of an operators position. i v 11.60 It is believed that the present system will best be understood by describing the operations involved in establishing a telephone connection from a calling to a called telephone line. 7 255 When the calling subscriber at substation A initiates a call by removing his receiver from its switchhook, the line relay 5 is energized through the back contacts of the cutoff relay 6 over the two sides of the calling linezfim in series. The operation of the line-relay lights the lamp 7 indicating that a call is awaiting attention whereupon the operator inserts the plug P of an idlecord circuit into-the jack J of the calling line. The answering supervisory relay 8 is then operated to prevent the lighting of the answering supervisory lamp 9, in a circuittraceable from grounded battery through two. of the windings of the repeating coil,' winding of relay? to 8, the tip and ring conductors of the cord circuit and thence through the plug P and jack J-over the'two sides of the calling line in series. I i

Adso when the plug P is inserted injack cfi J the cutofl relay 6 is operated to disconnect the linerelay from the control of the calling line whereupon the line lamp 7 is extinguished. The energized circuit of the cutoff relay 6 extends from ground, windingap of this relay, sleeve contacts of the jack J and plug P. sleeve conductor 10, winding of the sleeve relay 11 to grounded battery. The relay 11 is likewise operated over the circuit just described and eii'ects the energi- Zation of the automatic listening relay 12 which connects the operators telephone set (not shown) over the conductors 13 to the answering endof'the cord circuit taken for use. The energizing circuit forthe listen Lil ing relay 12 is completed from grounded battery, inner armature and front contact of sleeve relay 11, conductor 14, winding of the relay 12, conductor 15, uppermost continuity spring and contact of relay 16, conductor 17, to ground at the lower armature and contact of relay 18. The operator now inquires for the number of the wanted line which is assumed to be the line terminating at the substation B and then tests for the busy or idle condition of this line by touching the tip of the plug P to the jack J Since the sleeve of this line is connected to battery when the line is busy, this busy condition is indicated by a distinctive click in the operators headset when the tip of the plug P touches the sleeve of the jack J. If, however, the line is idle at the time of making such a test, the operator hears no click indicating that the call may be completed she inserts the plug P into the jack J.

As soon as the plug P engages the jack J the sleeve relay 19 is energized from grounded battery, winding of this relay, sleeve contacts of plug P and jack J, winding of the called line cutoff relay 20 to ground. The operation of the relay 19 closes a circuit from grounded battery, its uppermost armature and front contact, conductor 21, inner, back contact and armature of relay 18, conductor 22, winding of relay 23, to ground, causing the operation of this last named relay. The operator now depresses the ringing key 24 which results in the operation of the relay 25 from grounded battery, winding of this relay, ringing key contacts 24-. to ground. lVith the relays 23 and 25 energized, an operating circuit is C0111- pleted for the relay 26 from grounded battery, winding of this relay, front contact and armature of relay 25, inner, lower front cnnimtand armature of relay 23 to ground.

The ringing relay 28 is now energized from ground at the lowermost back contact and of relay 29, conductor 30, armature and back contact of trip relay 81, winding of relay28, conductor 32, front contact and armature of relay 12, conductor 34-, lowermost armature and front contact of relay 23, front contact and armature of relay 26, through the resistance unit to grounded battery. Relay 28 when thus operated closes a locking circuit for itself from grounded battery, inner armature and front contact of relay 19, conductor 35, back contact and upper armature of relay 16, conductorc36, armature, front contact, and winding of relay 28 and thence to ground at the armature and back contact of relay 29 over conductor 30. Relays 23 and 26 in turn effect the operation of the relay 27 from grounded battery, winding of this relay, inner front contacts and armatures of relays 26 and 23 to ground. The relay 27 is sluggish in at tracting its armature in order to insure the energization of the ringing relay 28 before the operation of the relay 18 which last named relay is effective to effect the release of relay 12 which in turn disconnects the operators telephone set from the cord circuit now in use. The energizing circuit of relay 18 extends from grounded battery, inner armature and front contact of relay 19, conductor 35, winding of the relay 18, front contact and upper armature of relay 12, conductor 37, inner, upper, back contact and armature of relay 38, front contact and armature of relay 27, to ground. Relay 18 when thus energized closes a locking circuit for itself from ground, through its own continuity spring and contact 39 and its own winding, and thence to grounded battery, over conductor 35 as previously oescribed. The relay 18 at its lowermost armature and back contact opens the holding circuit of the automatic listening relay 12 which deenergizes and disconnects the operators telephone set from this cord circuit. At the innermost, upper armature and back contact of relay 18, the energizing circuit of the relay 23 in the common key circuit is opened causing the relays 25, 26 and 27 to decnergize thereby permitting the common key equipment to revert to use on other cord circuits.

As soon as the ringing relay 28 is energized, ringing current is supplied to the called line from the ringing current source,

upper winding of the trip relay 31, lower,

back contacts and armatures of relays and 71, innermost front'contact and lower armature of relay 18, lower front contact and armature of relay 28, ring contacts of plug P and jack J thence over the called line and through the ringer atsubstation B, over the upperside of the called line, tip contacts of the jack J and plug P, uppermost front contact and armature of relay 28 to ground at the uppermost back contact and armature of relay 71. Ringing current is supplied over this circuit until the called party responds at which time the trip relay 31 is operated and at its armature and back contact interrupts the locking circuit for the ringing relay 28 which deenergizes and closes the break points which existed in the talking leads of the cord circuit so that the calling and called substations are now connected over a conversational circuit.

The present system is equipped with party line ringing whereby any one of four substations on a telephone line may be selectively signalled. In order to select ringing current of the proper frequency to signal a wanted station on a party line, four ringing keys 2%, 74, and 7 6' are provided for the common use with all of the cord circuits of an operators position. It has previously been described that when the ringing key 24 is depressed proper ringing current to signal the substation B having designation W, is applied to the called line. In the event that it is desired to signal another subscriber on this line whose designation may be R the ringing key 74 is depressed which results in the operation of the relay 77. This effects the energization of the ringing current selecting relay 70 in a circuit traceable from ground, upper armature and front contact of relay 77, conductor 78, lower armature and front contact of relay 12, winding of relay 70, conductor 79, conductor 35, inner, front contact and armature of relay 19 to grounded battery. Relay 70 when thus energized locks itself operated from ground at the back contact and armature of relay '29, conductor 30, armature and back contact of relay 31, conductor 80, front contact, armature and winding of relay 7O thence to grounded battery over conductor 79 as previously described. In the event that the operator desires to. signal a called subscriber whose designation may be J, ringing key 75 is depressed to operate relay 81. This results in the energization and subsequent locking of relay 71 over circuits similar to those just described for the relay 70. If, however, it is desired to signal the called party whose designation may be M, ringing key 76 is depressed to operate the relay 82. This in turn results in the energization and subsequent locking of both ringing selective relays 7 0 and 71. The operated or non-operated condition of relays 70 and 71 determines the character of ringing current which is applied through the trip relay 31 to the called line.

If the wanted subscribers line terminates in another exchange, the operator inserts the plug P into the jack J2 ofa' trunk leading to that exchange where the call may be completed by a second operator. The originating operator then depresses the trunk key 40 which is effective to operate the relay 41. On the operation of this relay a circuit is closed from ground, its lower armature and front contact, conductor 37, armature and front contact of relay 1'2, winding of relay 18, conductor 35, inner front con'fact and armature of sleeve relay 19,'to ground. As indicated in the case of a local call, the relay 18 effects the deenergization of the relay 12 which in turn disconnects the operators telephone se'; from the cord circuit just taken for use. In the case of such a trunk call the ringing relay 28 is not operated and consequently no ringing current is transmitted over the selected trunk.

The present system is provided with an arrangement whereby completed calls may be charged to a calling subscriber. As soon as the call has proceeded to the pointwhere the relay 19 operates the slow releasing relay 42 is energized in a circuit from grounded battery, uppermost armature and front contact of relay 11, winding of relay 42,

.middle armature and front contact of relay 18, upper armature and back contact of relay 44, conductor 30, lower armature and 3 back contact of relay 29, to ground. Vhen the call has proceeded to the point where the calling supervisory relay 46 is energized on the response of the called party, a'circuit is extended from ground, armature and;

front contact of relay 46, conductor 48, winding of'relay 44, conductor 35, inner, front contact and armatureof relay 19, to grounded battery. Relay 44 is energized in this circuit and effects theoperationor.

relay 43 in a circuit traceable from grounded battery, winding of the relay, lowermost front contact and armature ofrelay 44,'ar mature and front contact of relay 42 to ground. lVhen the relay 43 operates, it

completes at its lower armature and front contact an energizing circuit for the slow operating relay 45. The metering circuit is now closed from a source of high potential current (not shown) over conductor 49' scribed so thatthe calling line meter is operated, once and once only, over the metering circuit 49, on the completion of each call.

If, how-ever, a call shouldnotbe charged to the calling substation, the non-register key 83 is depressed; This results in the operation of the relay 44 into a circuit extending from ground, closed contacts of key 83, conductor 84, lower armature and front contact of relay12, conductors 85 and 48,

winding of relay 44, conductor 35, front contact and armature of relay 19 to grounded battery. Under the non-register condition, the relay 44 operates to prevent the energization of relay 42 in Fig. 1 so that it s impossible to complete the metering circuit and consequently metering current is not applied to the sleeve circuit 10 of the calling line. i r

If the calling subscriber desires to regain" battery, uppermost armature and cont-act of- When the relay 45 scribed.

relay 11, back contact and armature of relay 8, through the resistance unit, back contact, continuity spring and winding of the relay 29, conductor 50, uppermost front con tact and armature of relay 18, normally closed contacts of the listening key 51 to ground. The relay 29 as soon as it 18 operated closes a locking circuit for itself from. grounded battery, its uppermost armature, front contact and winding and thence to ground over conductor 50 as previously de- Also when relay 29 is operated the lamp 9 associated with the calling line is intermittently lighted in the following manner. An energizing circuit is closed for the lamp 9 from grounded battery, armature and front contact of relay 29, through the resistance unit, lamp 9, front contact and armature of relay 11, to ground. Also at the inner armature and front contact of relay 29, a circuit is closed from grounded .relay 53, lower winding of relay 54 to ground. This last described circuit shunts the lamp 9 but energizes the relay 51 which closes a circuit over conductor 55, from the interrupter (not shown), front contact and armature of relay 54, winding of relay 53 to grounded battery. The relay 53 is intermittently operated in accordance with the adjustment of the interrupter and on each operation of this relay at its back contact and continuity spring it interrupts the conductor which has been short circuiting the lamp 9 permitting it to operate. During the time that the relay 53 is operated the relay 54 is held operated through both of its windings in series but when relay 53 deenergizes relay 54 is held operated through its lower winding.

In the past it has been the practice on local calls when a line tested-busy to insert the answering plug such as P of the cord circuit taken for use into a busyback jack through which an interruptedbusy tone was supplied over this cord circuit to the calling line. In the case of such a busy call the operators time was unnecessarily taken up in plugging into the busyback jack and subsequently taking down that connection. In accordance with the present invention it is proposed to provide a busyback key 57 which is common to all of the cord circuits at an operators position so that when a called line tests busy it is only necessary for the operator to depress the busyback key momentarily after which the busy tone is transmitted to the calling line until the sub scriber hangs up or until the answering plug is withdrawn from the calling jack, or until the operator subsequently tests the busy line,

finds it idle and completes the connection thereto.

The depression of the busyback key 57 effects the energization of the slow releasing relay 38 from grounded battery, winding of this relay, contacts of the key 57, back contact and armature of relay 23 to ground. As soon as relay 38 operates, at its lower most front contact and armature, it completes an energizing circuit for the slow operating circuit 27. The operation of the relays 27 and 38 complete a circuit from ground, armature and front contact of relay 27, middle armature and front contact of relay 38, conductor 58, contact of relay 12, winding of relay 16, innermost front contact, and armature of sleeve relay 11 to grounded battery. Relay 16 when operated closes a locking circuit for itself from grounded battery, inner armature and front contact of relay 11, winding of relay 16, its innermost lower front contact and armature, conductor 59, contacts of the manual listening key 51 to ground. At the back contact and continuity spring of relay 16 the energizing circuit of the automatic listening relay 12 is opened, permitting this relay to decnergize so that the operators telephone set may be used in connection with other cord circuits. Before relay 12 releases the ringing relay 28 is operated from ground at the back contact and armature of relay 29, conductor 30, armature and back contact of trip relay 31, winding-of the ringing relay 28, conductor 32, front contact and armature of relay 12, conductor 34, uppermost armature and front contact of relay 38 through the resist ance unit to grounded battery. On the operation of the relay 28, it looks itself energized from grounded battery, inner armature and front contact of relay 11, front contact and armature of relay 16, conductor 36, rmature, front contact and armature of relay 28, andthence to ground over conductor 3O previously described.

It will be noted that although the ringing relay 28 is energized, the ringing current is ineffective since the plug P is not inserted into the jack of the called line but instead busy tone current is supplied from the source BZ over conductor 60, lowermost front contact and armature of relay 16, inner, back contact and armature of relay 18, lower, front contact and armature of ringing relay 28 and thence over the lower side of a portion of the cord circuit, and the lOW- or right hand winding of the repeating coil, to grounded battery. This tone is repeated to the calling subscribers line until the subscriber replaces his receiver on its switchhook at which time the answering supervisory relay 8 is released to give the disconnect signal. This signal is given by the lighting of the lamp 9 from grounded batarmature and front lilo the release of the sleeve relay 11, all of the relays of the cord circuit including relay 16 and ringing relay 28 are restored to normal. It Will be noted that the circuit of the ringing relay 28 while being used to control the transmission of the busyback signal, is completed at the lowermost armature and back contact of the flash recall relay 29 so that if the calling subscriber elects to initiate another call he may signal the operator as in the case of an ordinary recall by moving his switchbook up and down to effect the operation of the flash recall 29 which in turn disconnects the busy tone.

It will be understood that the present disclosure is merely typical of one form of the present invention and there may be many variations and modifications thereof within the scope of the claims without departing from the inventive idea.

lVh-at I claim is:

1. In a telephone system, a telephone exchange, telephone lines terminating at said exchange, a plurality of cord circuit, at said exchange, means including one of said cord circuits for interconnecting one of said telephone lines as a calling line and another of said telephone lines as a called line, means for characterizing said telephone lines as busy or idle, a source of busy tone, and means including a busy back key common to said cord circuits for transmitting a busy tone to a calling telephone line when the called telephone line is busy.

2. In a telephone system, a telephone switchboard, telephone lines terminating at said switchboard, a plurality of cord circuits at each switchboard, any one of which cord circuits may be used for interconnecting one of said telephone'lines as a calling line and another of said telephone lines as a called line, means for characterizing any telephone line as busy or idle, a source of busy tone, and means including a busy back key common to said cord circuits for controlling the transmission of a busy tone to said calling telephone line when said called telephone line is busy.

3. In a telephone system, a telephone exchange, telephone lines, means including a cord circuit for interconnecting said telephone lines, a source of ringing current for signalling said telephone lines, a source of busy tone, a ringing relay in such cord circuit for controlling the application of said ringing current to a called telephone line, and means including said ringing relay for connecting said busy tone to said calling telephone line when the called line is busy.

4. In a telephone system, a telephone exchange, a calling telephone line and a' plurality of called party telephone lines terminating at said exchange, a plurality of cord circuits any one of which may be used for interconnecting said calling telephone line and a called telephone line, a plurality of sources of ringing current for selectively signalling any one of the parties on a called telephone line, a source of busy tone, a ringing key'for each source of ringing current common to said cord circuits, said ringing keys serving to control the selection of the proper source of ringing current to signal a desired party on a called line, source of busy tone, and a busy back key common to said cord circuits for controlling the'conneetion of said busy tone to said calling telephone line when a called line is busy.

5. In a telephone system, a calling telephone line, a plurality of called telephone lines, a plurality'o'f cord circuits, any one of which may be used for interconnecting said calling telephone line and a desired called telephone line, means including a recall relay for signalling when said calling tele phone line initiates a recall, a source of ringing current, a rin ing relay in each cord circuit for controlling the connection of ringing current to a called telephone line, a source of busy tone, a busy back key, means including said ringing relay for connecting said tone to a calling telephone line, and a circuit for said ringing relay controlled by said flash recall relay and by said busyback key.

6. In a telephone system, a calling telephone line, called telephone lines, a; plurality of card circuits, any one of which may be used for interconnecting said telephone lines, an operators telephone set, automatic listening means responsive to the extension of a cord circuit to said calling telephone line for connecting said operators telephone set to said cord circuit, means responsive to the completion of the extension of the call through said cord circuit to the called telephone line for disconnecting said operators telephone set from said cord circuit, a source of busy tone, a relay for connecting said source of busy tone to a calling line, means including a busy back key and said automatic listening means serving to control the operation of said relay, and means independent of said automatic listening means for maintaining said relay operated.

7. In a telephone system, telephone lines, a plurality of cor-d circuits, any one of which may be used for interconnecting said telephone lines, an operators telephone set, an automatic listening relay operated responsive to theestension of a cord circuit to a calling telephone line, said automatic listening relay serving to connect said operators telephone set to said cord circuit, a source of busy tone, a busy back key and a slow releasing relay controlled thereby common to said cord circuits, a relay for connecting said source of busy tone to said calling line, and means including said automatic listening relay and said slow releasing relay serving to control the operation of said relay.

8. In a telephone system, a calling telephone line, a called telephone line, a plurality of cord circuits any one of which may be used for interconnecting said telephone lines, an operators telephone set, an automatic listening relay responsive to the ex tension of a cord circuit to said calling telephone line for connecting said operators telephone set to said cord circuit, a source of busy tone, a busy tone relay for connecting said source of busy tone to a calling line, a. busy back key and a slow releasing relay controlled thereby common to said cord circuits, and a circuit for said busy tone relay controlled at front contacts of said automatic listening relay and said slow releasing relay.

9. In a telephone system, telephone lines, a plurality of cord circuits, any one of which may be used for interconnecting a calling telephone line and any one of the other telephone lines, means including a recall relay for signalling when said calling telephone line initiates a recall, an operators telephone set, an automatic listening relay responsive to the extension of a cord circuit to a tele phone line for connecting said operators telephone set to said cord circuit, a source ofbusy tone, a busy back key and a slow releasing relay controlled thereby common to said cord circuits, a relay for connecting said source of busy tone to said calling line, and an operating circuit for said relay controlled at contacts of said previously men tioned relays.

10. In a telephone system, a calling telephone line, a plurality of called telephone lines, a plurality of cord circuits, any one of which may be used for interconnecting said calling telephone line and any one of,

said called telephone lines, means including a recall relay for signalling when said calling telephone line initiates a recall, an op erators telephone set, an automatic listening relay responsive to the extension of a cord circuit to a telephone line for connecting said operators telephone set to said cord circuit, a source of busy tone, a busy back key and a slow releasing relay controlled thereby common to said cord circuits a relay for connecting said source of busy tone to said calling line, an operating circuit for said relay controlled at contacts of said previous ly mentioned relays, and a locking circuit for said busy tone relay independent of said slow releasing relay and said automatic listening relay.

In Witness whereof, I hereunto subscribe my name this 2nd day of May A. D. 1930. WILLIAM J. VINCENT.

DISCLAIMER 1,821,193.-Wtlltam J. Vincent, Rochester, N. Y.

dated September 1, 1931. Disclaimer filed October 5, 1932, Rochester Telephone Corporation.

Herebv enters this disclaimer to so much of claims 1 and 2 wherein the term telephone lines is not limited to subscribers or substation telephone lines.

[Ofiicial Gazette November 1, 1932.]

TELEPHONE SYSTEM. Patent by the assignee,

Images