US1971672A - Telephone system - Google Patents

Description

8, 1934. L. B. APPLETON 1,971,672

TELEPHONE SYSTEM Filed May 26, 1932 2 Sheets-Sheet l I 43 am ream! INVENTOR LOUIS B. APPLETON ATTORNEY W L. B. APPLETON TELEPHONE SYSTEM Aug. 28, 1934.

Filed May 26, 1932 2 Sheets-Sheet 2 INVENTOR LOUIS B- APPLETON QZ. WA

ATTORNEY Patented Aug. 28, 1934 s ATSE 1,971,672 TELEPHONE SYSTEM Louis B. Appleton, New York, N. Y. Application May 26, 1932, Serial No. 613,748

12 Claims. (o1. 1711-2) My invention relates to novel apparatus for and methods of operating telephone systems and more particularly relates to novel apparatus for and methods of operating broadcasting telephone sys terns.

The use of telephone lines for broadcasting special features such as news, lectures, concerts and the like, is well known. In these systems, however, as in radio broadcasting, it is not possible to determine how many subscribers or"1istenersin are receiving the broadcast, and the economical value thereof is accordingly not known.

aremany instances where a broadcaster has special i-forrnation which he desires to sell --to a specific group-of listeners-in who would bewilling to pay a fee for such service.

Accordingly, an object of my invention is to provide novel methods of means for recording the number of listeners-in in a telephone broadcarit.

A further object of my invention is to provide novel apparatus for and methods of making a special charge to subscribers calling a particular telephone number.

'Thereare other objectscf my invention which together with the foregoing will appear in the detailed description which follows in connectionwith the drawings in which; l

l diagrammatically illustrates an autornaticj telephone system embodyin a preferred form of my invention.

Figure 2 a circuit diagram representing a" portionof amanual system embodying myinvenjinn; and

Figure 3 is a modified form of an automatic system for. carrying out my invention.

In Figure l I have shown, for purposes of simplicity, only so much. of the system as is necessary to make the inventionclear, it being understood that standard equipment to complete the system may be added. A calling, a broadcast sub scribers line, a d substation of the broadcast subscriber, is disclosed, with one connector for each calling subscriberto complete the connections between the calling subscribers and the called subscriber. 'It will be understood, however, that in each of these systems having more than one hundred lines, one or more selectors, and

tioning his system for connection by any number of calling or listening-in subscribers. Ground is thereupon applied to the conductor 84 for the purpose to be explained in more detail hereinafter.

As will appear in the detailed description which follows, this enables any calling subscriber now to connect into his telephone. As each connection is made, a meter device is automatically p erated thereby to provide an indication of the number of listeners-in. At the same time, the meter at the calling subscriber's substation is automatically operated a predetermined number of times to make a'predetermined charge for this special call. The calling subscribers telephone is also rendered non-operative to prevent the calling subscriber from carrying on any conversation at this time. 1

When the subscriber at substation 1 initiates the call which is to terminate in a connection to the broadcasting subscriber, he removes his receiver from a switch hook and the line relay2 is energized over a circuit from ground through the battery 3, the line relay '2, back contact and armature 4, through the telephone dial5, telcphone transmitter 6, contacts at the switch hook. '7, through the telephone 8, over the conductors, and armature and its back contact, to ground. I

The line relay 2 is energized and in turn com pletes an operating circuit for the motor magnet 12 from ground through battery 13, the motor magnet 12, its armature 14 and back contact,

armature, 15 and its front contact, backcontact and armature 16, and over the test brush 17, selectors 21, test concluctor22, front contact and the armature 23 of the slow relay. 24, conductor 25, armature 26 and its back contact, to ground.

This circuit, as is well knownv in the art, is only completed if the brushes 17; 18 and 19 are not in engagement with the terminals of an idle trunk, the line switch in the present case being of the rotary type for purposes of illustration. The completion of this circuit, however, energizes the motor magnet 12 which opens its own circuit at armature 14. Magnet 12 is intermittently energized and deenergized, moving the brushes 17 to 19 from one set of other until an idle set is found. a The cut-off relay 31 during this time, although a circuit is completed for it from grounded battery 13 and the winding of the motor magnet 12,

trunk terminals to anwinding of the cut-01f relay 31,and the front contact and armature 32 to. ground, is not oper-v ated because its Winding is short circuited by the gized, the motor magnet 12 is no longer operated and the short circuit around relay 31 is no longer effective. Relay 31 will thereupon be energized in series with the motor magnet 12 and over the circuit described above. The winding of the motor magnet 12, however, is such that this magnet is not efiective when operated in series with the cut-off relay 31. On operation of the cutoff relay 31, the lines 33 and 34 of subscriber 1 are extended through the armatures 4 and 10 in engagement with their front contacts to the brushes l9 and 18, respectively.

This circuit extends through the selector 21 and the conductors 35 and 36 to windings of the relay 37 in series to ground and grounded bat-' 'the relay 24 is operated to complete a holding circuit for the cut-off relay 31 extending from grounded battery 13 through the motor magnet 12, armature 14 and its back contact, through the winding of the relay 31, front contact and armature 16, brush 1'7, selector 21, conductor 22,front contact and armature 23, and armature 26 and its back contact, conductor 41,,armature 42 and its back contact, to ground.

For purposes of this description, it has been assumed that the calling subscribers line has been extended through one ormore selectors, depending on the size of the system, to the connector of Figure 1 through which the called subscribers line may be reached' It has been previously described how the extension of the calling line to these subscribers results in the operation of relay 37.

The connector switch is now in condition to receive impulses corresponding to the tens digit of the broadcasting subscribers number. The subscriber at 1 now operates his dial sender in the well known manner to transmit the tens series of impulses. In response to each of the impulses in this series, the impulse relay 37 retracts its armature but the slow releasing relay 24 does not release its armature during the normal interruption of its operating circuit at the front contact and armature 38 of relay 3'7. On each retraction of the armature 38 of relay 37,

a circuit is closed from ground over armature 38 and its back contact, armature 43 and its front contact, winding of the change-over relay 44, primary motor magnet 45 and the side switch wiper 46 in its first position to grounded battery 4'7.

'On the first completion of this circuit thechangeover relay 44 attracts its armature 51 and. thereby completes a circuit from ground through armature 51 through the escape magnet 53 to grounded battery 47.

As is wellknown, the escape magnet 53 on its deenergization serves to advance the side switch wiper 46 one step. On each completion of the circuit described as extending through the change-over relay 44, the primary motor magnet 45 advances the brushes 5'7, 58, 59, and 60 of the connector one step in their primary movement. At the close of the ten series of impulses, the impulse relay 3'7 holds its armature attracted for an appreciable interval so that the change-over relay 44 deenergizes, opening the holding circuit of the escape magnet 53 at the armature 52. The escape magnet 53 thereupon deenergizes to advance the side switch wiper 46 into its second position.

The connector switch circuits are now in readiness to receive the unit series of impulses transmitted from the calling subscribers dial. In response to each of these impulses, the impulse relay 3'7 retracts its armature as in the case of the previous series of impulses, but the unit impulses are now eifective to control the secondary motor magnet 61 over a circuit extending from ground over armature 38 and its back contact, armature 43 and its front contact, through the changeover relay 44, and through the secondary stepping magnet 61, and the second contact switch 46, through the battery to ground. The switch 46 it will be understood was moved to this second position on the operation of the changeover relay 44 described hereinbefore.

On the first completion of this circuit, the change-over relay 44 is again energized as in the case of the ten series of impulses and likewise holds the escape magnet 53, energized over the circuit traced hereinbefore. In response to each of the units impulses, the secondary motor magnet 61 has its operating circuit closed so that it operates the brushes 57 to 59 of the connector in a step-by-step movement in a secondary direction.

When the brush wipers 5'7, 58, and 59 come to rest on the contacts extending to the called subscribers lines 81 and 82, an energizing circuit is completed for the relay 83 from ground to battery, contact 59, winding of the relay 83, conductor 84, contact 85, to ground. In the above it is assumed, as has already been explained before, that the called subscriber contrariwise to the present practice, has already removed his receiver from the hook at the time when the calls begin to come in and accordingly the contact 85 is closed, as indicated in the above described circuit.

The battery over contact 59, it will be noted, also extends over the conductor 91, armature 92, and its back contact, to the contact 93 of a switch 94 through its brush 95 and the counting magnet 96, to ground. The switch 94 is provided with a plurality of contacts, each of which extends to a similar calling equipment so that each calling party prepares an energizing circuit over an individual contact of the switch 94 for the counting magnet 96. The wiper 95 is stepped from contact to contact by means of the stepping magnet 97. The stepping magnet 97 in turn is controlled over the contact 85 and, as is well known in the art, as its circuit is intermittently interrupted at the contact 98, it functions to step the wiper 95 from contact to contact. This operation, as will be obvious, takes place after the calling operator has removed his telephone from the hook and closed the contact 85.

When the wiper 95 engages the contact 93 individual to the calling equipment of a particular calling subscriber, a circuit is completed for the counting magnet 96, as described above. At armature 99, an energizing circuit is also completed for the relay 101 over the switch 100 i which in turn opens the energizing circuit for the counting magnet 96 at armature 92 and locks itself over its armature 102 and its front contact and conductor 84 to the contact 85. This prevents energization of the counting magnet 96 more than once for that particular calling subscriber.

.-As has been explained heretofore, it is desirable that the calling subscriber in calling this of particular number he charged with more than one telephone call because of the special nature of the service to be provided thereof. To this end, a further switch 103 is provided having a wii fir 104 which is stepped from contact to corn 1 tact by the stepping magnet 105 which also breaks itself on circuit intermittent at its Own armature loo. The circuit for magnet 105 is com.- pleted from battery on conductor 91 when the switching operation is completed. As the wiper 104 is stopped from contact to contact'impulsesmakinga special charge for calling thisparticu lai number. v p When the brush 104 engages the last contact "107 onthe switch 103 operated in the same shaft I with switch 103, an energizing circuit is completed for, the stepping magnet 105 which is independent of its own armature 106i Stepping a o magnet 105 is accordingly now maintained en- "'ergized until the receiver is again placed on its hook and the contact at is brokenl Atthe calling subscriber's station, the magnet 109"in addition to operating themeter 110, 35, also drives brusheson switch 115 which engages "contacts 116 whenthe predetermined number of charge-impulses is received to provide a bypass around the telephone, preventing talking by the calling party. i d0,- ,When the called party hangs his receiver on the hook again, ground is removed from the conductor stand the relays 83 and '75 are deenergized. disconnecting the calling party from the system. At armature 108, the circuit to the calling Dartys cat meteris opened. Similarly, the circuit for the stepping magnets 97 and 105 are opened and these magnets are deenergized to step their wipers and, 104, respectively, back to their first normal contact. The locking circuit ,for relay 1.01 is also 50,,deenergized, restoring the armatures 92 and 102 "to their normal position and the apparatus is back to normal. Similar operations, of course, occur for each of the other calling subscribers, the apparatus in each instance being restored to 55., normal- -v As will now be clear, conversation in one direction only can be obtained in my improved system. The control of the connection is entirely with the called subscriber, who by lifting his telephone from the hook, conditions his circuits on topermit connection thereto and by restoring the telephone to its hook, disconnects all calling subscribers connections. Provision is made for making a special charge to the calling subscribers-and at thesame time recording all 01 the calls made 6b, to the called party's line.

. In Figure 2, I have shown a manual telephone system to which my invention has been applied, and it will be more fully understood by reference to theiollcwin detailed description thereof it; 4 The conductors 200 are ordinary telephone subscriber line terminating at one end at a subscrib'ers station 201 and at the other end in a central office 202. At the station 201, the usual telephone set 203 is provided for an ordinary telephonic purpose and a supplemental key 204 is p ovided. for associating with theline a broadcasting receiving equipment 205.

At the central station 202, the line terminates in the usual type of switching jack 206 whereby telephonic communication may be established 80 through the cord circuit 207 between the line 200 and other lines terminating at the exchange. Normally the line 200 is connected over the armatures 208 and 209 and their back contacts of the relay2l0 to the jack 206 but the circuit of the. relay 210 is so arranged that the line may be disconnected from: the jack 206' when the key 204. at thecalling subscribers substation is operated. This circuit then extends through the transformor 212 to the program distributingequipment 202 with which the broadcasting subscriber is provided for his special broadcast and which is common to a large number of lines, as indicated.

The central program equipment itself is illustratod at 202 and is of a, very simple type consisting in its most fundamental form of an ordi-, nary telephone transmitter and an energizingbattery such as is in common use in telephone substations today.

At the central oiiice, in addition to the usual line relay 215, a special relay 216 is bridged across the line, the latter relay operating when the key 204 is actuated by the subscriber to energize the relay 210 which functions to disconnect the line from the jack 206 and connect it to the program equipment at 202 at the same time'applying a busy tone to the sleeve conductor of the jack to notify the central operator when testing the terminal that the subscriber is using the line1 for receiving the program. The relay 210, as will appear hereinafter, also functions tofioperate a metering device 217 consisting of a metering relay 218, a. switch 219, and a stepping magnet 220 for the broadcast subscriber,

One contact on the switch 219 is individual to the apparatus associated with the line 200 andeach of the other contacts are individual to each of the other lines. i i

The line relay 215 is marginal and 'doesnot operate through the high resistance connection established by the key 204 and will onlyoperate when the line is closed through the low impedance telephone set 203 by taking the receiver 'from the switch hook. It the subscriber should desire to use the line for ordinary telephonic purposes; theline relay 215 will operate as soon as thereceivcr is taken from the hock, thereby causing the line lamp 221 to glow. At the same time, it opens thccircuit of the relay 210 to prevent therelay 216 from actuating the relay 210 to discon-. ncct the line from the jack 206. The operator, upon observing the glowing of the line lamp, may establish a connection in the usual manner by means of a. cord circuit 207.

If, upon an incoming call, the operator desires to establish a connection with the line 200, the busy tone on the jack will be disregarded if the subscriber is receiving program service and aconnect'ion established by inserting the plug of the cord 207 in the jack 206. This operates'the cut-elf relay 222 which in turn disconnects the special relay 216 and the line relay 210 from the line.

At the subscribers station, the transformer 25; which serves to associate the loud speaking receiver 205 with the line, isprovided with a cone denser shunted by a highresistan'ce winding of a polar relay 226. Owing to the high resistance of the latter, when the key 204 is thrown,onlyu sufliclent current flows through the bridgein-150;

cluding the windings ofrelays 216 and'21'5- at: the central station" to operate the relay 2l6,"the'" line relay 215 notbeing operated when the set" is used for program purposes The'polar relay- 226 at the calling subscribers station controls a relay 227 whereby the loud speaking receiver 205 may be disconnected from the line, even though the key 204 is actuated. 1

The polar relay 226' is so poled as to energize the relay 227' forthis purpose only when battery is supplied to the line from the cord-circuit 207, the battery connections through the windings of: the relays 215 and 216 being reversed with respect-to the cord circuit. Consequently, the relay 226' disconnects the loud speaking receiver only when the operator inserts the plug'cr" the cord' circuit207 into the jack 206 to establish an ordinary telephone connection. This obviates any possibility'of ringing current actuating the loud speaking receiver and annoying the subscriber. A low resistance relay 228 is included in series with the subscribers set 203, said relay operating to disconnect the polar relay 226. Loud speaking receiver 205 is controlled from .the line'200 through-an auxiliary relay 230 whenever the subscriber takes down the receiver to usehis set for ordinary telephonic purposes. Thisarrangement is provided so that the special receiving equipment will be disconnected under these circumstances even though the subscriber should fail to restore the key 204.

The detailed operation is asfollows: Assum ing that the subscriber at station 201 desires to receive program services, the key 264 is actuated thereby closing-a circuit through the winding of the high resistance polar relay226, over the normal contacts 231 and 232 of the relay 230, over the make contacts 233 and 234 of the key 2045,- over the line 200, armatures 235 and 236 and their- ;back contacts of the relay 222, and through the winding of the special relay 216 and the line' relay 215.

The special relay 216 is operated'over this circuit but the current flow is not in a 'direction'to operate the relay 226. The marginal line relay.-

plied to the sleeve conductor of the jack 206 to appraise, the central office operator when testing the terminal that the subscriber is receiving the distributed information. I i The wiper of switch 219 is in operation, stepping. from contact to contact by the intermittentoperation of the'stepping magnet 200 which has previously been started into operation bythe depression of the key 244 started into operation just before the program isto be transmitted and when the calling subscribers begin to connect in on this circuit. As the brush of switch 219 engages the first contact,"the circuit will be completedfor the counting magnet 218 which will operate a" counting device. Atthe same time, relay 220 is energized and locksitself over its front con--v tact to prevent further energization of the relay 218 by thisv particular equipment; When the apparatus. is restored tonorrnal, relay 220 will deenergize. Operation of the counting device at the calling subscriber's ofiice to make .a

w to hear by means of the loud speaker 205, the information distributed from the broadcasting station 202."

If while the line is thus in use, a sufiiciently urgent call should come into the central switching ofiice for the line 200, the operator may disregard the" busy tone on the sleeve of the jack 206, and. insert the plug of the cord 207 into the jack 206, which thuscompletesa circuit over the sleeve of the jack 206 through the cut-off relay 222. The cut-off-relay 222 is thereupon energized and oper-- ates to'disconnect the'special relay 216 and the line relay 215 from the line. Relay 215, upon being deenerg'ized, opens a circuit of the relay 210', which at once disconnects the line 200 from the station- 202 and connects it to the tip and ring of the jack 206. The direct current supplied to the line 200through the windings of the relays 215 and 216 was'not in such 'a'direction as to actuate the high resistance polar relay 226, but as soonasthe cord circuit is connected to the line and the relays 2'16 and 215 disconnected, the direct current supplied th'rough the cord will be in such a direction as to actuate the polar relay 226 and close the circuitof the relay 227, which at once disconnects the loudspeaki'ng receiver 205 from the transiornier 225'. The relay 227 is looked over its right-hand front contact, right-hand back conta'ct' of relay 230 and lower make contact of key 20 1, so that said relay 227 will be held up independentlybr" the polar relay.

The subscriberrnay now be rung in the usual man er by the operator and'upon removing the receiveiiromthe hook, the talking circuit will beestablished -to the central ofiice. Direct current from the central office battery flows through the'cord circuitbver the subscribers line and through the relay 228, this relay being energized aslong as the receiver is removed from the hook. The relay 228 completes the circuit of the relay 230,- which disconnects the program receiving apparatus from the line independently of the key 204 and at its right-hand contact opens a lockmg circuitof the relay 227 which is restored to normal.

'At the end of the conversation, the subscriber hang up his receiver, thereby giving the usual disconnect signal and deen'ergizing the relay 228 which (if the key 204 has not been restored) again connects the polar relay 226 to the line. Current flows throughthe polar relay in such a direction as to energize and lock up the relay 227. As soon asthe' operator Withdraws the plug of the'cord 207 from the jack 206, the cut-off relay 222 is deenergi'zed, thereby again connecting the special relay 216 and line relay 215 to the line. The line relay 215 is not-energized but the special relay 216 is energized in series with the polar 40 relay 226'. The current flow is not in such a direction as to operate the polar relay 226 but the energization of the 's'ecial relay 216 again completes-a circuit of'the relay 210 which disconnects the line200'from the jack 206 and connects it to the broadcasting station 202. Transmission from'the program station may again be received by the loud speaking receiver 205 as soon as the subscriber restores the key 20 1 to unlock the relay 227 and then again actuates the key. 15

If, while the line is being usedfor receiving distributed information, the subscriber should de- "sire touse the line for establishing a telephone call, the receiver may be removed from thehook, thereby "energizing, in addition to the already energized relay 216, the line relay 215 and the relay 228; Therelay 228 actuates the relay 215 to disconnect the special receiving equipment in-- dependently of the key 204. The line relay 215 opens a circuit of the relay 210, which upon being deenergized, disconnects the line 200 from the program station and connects it to the jack 206. The line relay 215 at the same time completes a circuit of the linelamp 221 over its front contact. The operator will answer the call by inserting the plug of the cord circuit 207 in the jack 206 there- 'by causing the cut-off relay222fto-disconnect the relays'215 and 216 from the line as beforeso that the relay 210 remains deenergized with'the line connectedto the jack 206. At the end of the conversation the subscriber may hang up his receiver and the apparatus may be restored to the condition for program reception in the manner already described.

When the subscriber no longer desires to receive'the program service he will simply restore 'thekey i thereby disconnecting the loud speak- 'er andassociated apparatus from the line and opening the circuit of the special relay 216. The latter, upon being deenergized, will open the circuit of the relay 210, which will disconnect the line from the 'program equipment at 203 and connect it tothe jack 206. a

Figure 3 illustrates an arrangement for applying program service to telephone lines terminatingat a central office equipped for machine switching. At machine switching oflices no operators will be provided to exercise discretion with regard'to the urgency of incoming calls and in 1 practice the circuits might be arranged either to exclude all incoming calls while the special program equipmentis in use or to permit all incoming calls to interrupt the program service. The circuitillustratedin Figure 3 is arranged so that 'when the line is in use for program receiving no incoming calls may be .made. The subscriber himself ,"however, can interrupt the program servicetomake outgoing calls at any time by'sirnply removing his receiver from the switch-hook as inthe case of the circuit shown in Figure 2.

-In thisforrn ofthe invention the equipment at the subscribers station 301, both for program receiving and for ordinary telephonic purposes, is-"identicalwiththat shown in Figure 2, except I that the subscribers' telephone set is provided withthe usualform of dial 302 for operating the *s witchingmachineryat the central oflice.

The program equipment at thestation 303 and i'ts'association with the line 3 04at thecentral ofiice is also identical withthat illustrated in Figure 2; The line 304 terminates at the central office for the purpose of establishing incoming connectionsin the usualform of connector bank (not shown) while, for the purpose of establishing outgoing connections the line terminates in the well known Keith line switch and its associ- 'atedmaster switch. As these'elements are well known in the art, only a portion of the circuits thereof are illustrated-and the detailed construcnon thereof need not be described A "marginal line relay 305 isprovide'd, as in themanualsystem, thisrelay being only operated when the receiver is removedfrom the switch-hook Theline relay-cdntrols a doublewoundplunger magnet 306 5 of welfkrrown construction,- which performs the double function of acting as a cut-off relay and of operating the plunger to connect the line to the dial-operated switching machinery (not shown). The windings of the plunger magnet, as is well known, are so arranged that the upper winding, when energized, will cause the plunger 307 to operate. The lower winding, however, will not operate the plunger 307 but will only hold the plunger 307 in operated position if it has already been operated. In addition to the marginal line relay 305, a specialrelay 308 is provided, as in the manual system, said relay 308 functioning, if the line relay 305 is not energized to complete the circuit of the relay 309, which disconnects the stood from the description of the operation which is as follows: Assuming that the subscriber desires to receive distributed information or the like. The key 311 is actuated to connect the high impedance polar relay 312 and the loud speaking receiver 313 to the line as before.

This established a direct current circuit from battery through the line relay 305, through the winding of the special relay 308, over the upper contact of the plunger magnet 306, through a winding of the'retard coil, to the tip side of the line 304, upper make contact of the key 311, lefthand contact of the relay 314, make contact of the key 311, ring side of the line 304, through the right-hand winding of the retard coil at the central station and over the lower contact of the plunger magnet to ground, through the circuits of the master switch (notshown). The current flowing through this circuit is not suflicient' to operate the line relay 305 and is not in such a direction as to operate the polar relay 312. The special relay 308 is operated, however, and completes a circuit for the relay 309, which disconnects the line 304. from the connector bank terminals and connects it to the station at 303, so that distributed information from said station 303 is transmitted over the make contacts of the relay 309 and over the line 304tothe loud speaking receiver 313. It will be noted that while the line is in this condition a busy potential is applied to the sleeve conductor leading to the connector bank at the central ofiice, over the lower front contact of the relay 309. Therefore, if, while the line is being thus used, some other subscriber desired to converse with the subscriber on the line 304, the switching machinery (not shown) operated at the 'centralstation in: a well known manner to establish connection with the line 304,

will find the busy potential upon the sleeve and will therefore fail to establish a connection with the line. The program service cannot be 1111381? ruptedby an incoming call, therefore, if the special receiving equipment is in use.

A'furtherresult of the energization of relay 309 is t'o'operate armature 315 to its front contact, completing an energizing circuit for relay 316 which in turnat its armature 317 completes an Further details of the invention will be underknown manner.

desired, the calling subscribers may be made a special charge for this service in the manner described in connection with Figure 1.

If, while the program receiving apparatus is associated with the line by means of the key 311 so that the loud speaker 313 is being operated, the subscriber at station 301 should desire to use the line for ordinary telephone purposes the subscriber may remove the receiver from the switchhook, thereby establishing a low resistance connection over a circuit through the line relay 305, special relay 308 and the relay 314'. Relay 314' is energized and completes the circuit of relay 314, thereby disconnecting the loud speaking receiver and associated equipment from the line independently of the key 311. The marginal line relay 305 is operated over the low resistance circuit through the substation set and its left-hand contact opens a circuit of the relay 309, which upon being deenergized disconnects the line from the central program station. Over its right-hand contact the line relay 305 completes a circuit through the upper winding of the plunger magnet 306 (the portion of this circuit extending through the master switch is not shown) The plunger 307 is actuated by means of the upper winding of the plunger magnet to complete a circuit from the line 304 over the switches .controlled by the plunger magnet to the selector switches (not shown). The plunger magnet, upon being energized, disconnects the line relay 305 and special relay 308 from the line. Both relays are now deenergized so that the circuit of the relay 309 is maintained open. The actuation of the plunger switch completes a circuit from battery, through the lower winding of the plunger magnet and over the inner right-hand contact of the plunger switch (the complete circuit not being shown). The lower winding of the plunger magnet remains energized during the entire connection to hold the plunger in. actuated position. The upper operating Winding of the plunger magnet is deenergized as soon as the armature of the line relay falls off.

The line circuit 304, having been extended over the contacts of the Keith line switch under the control of the plunger 307 to the tip and ring conductors extending to the selector (not shown), the subscriber may manipulate the dial 302 in a well known manner, thereby transmitting impulses over the. line to the switching machinery and establishing the desired connection. At the conclusion of the conversation, the subscriberat the station 301 hangs up his receiver. This causes a release of the switching machinery in a well As soon as theswitching machinery is released the ground applied through such machinery to the conductor marked Release at the station 322 is removed therefrom, thereby opening the holding circuit extending over the inner right-hand contact of the plunger switchto the holding winding of the plunger magnet 306. The plunger magnet is now 'deenergized, releasing the plunger 307 which disconnects the line from the switching apparatus.

' The plunger magnet, upon deenergizing, also 309 so that the line may be again connected to the program receivingiequipment and placed in condition for receiving the distributed information as before.

If the subscriber desires to terminate the reception of distributed information he merely restoresthe key 311 to normal, thereby opening the circuit through the line relay 305, special relay 308 and polar relay 312. The loud speaking receiver and associated equipment is now disconnected from the line at the contacts of the key 311. The deenergization of the special relay 308 results in opening the circuit of the relay 309, which thereupon disconnects the line 304 from the program equipment at station 303 and connects the line to the switching terminals.

If, while the line is not being used either for ordinary telephone purposes or for program receiving a connection should be initiated through the switching machinery (not shown) for the line 304, no busy ground would appear at the sleeve conductor of the connector bank and consequently the connector would make the connection with the line terminals and complete a circuit over the sleeve conductor and the lower back contact of the relay 309 through the holding winding of the plunger magnet 306. The plunger magnet would be energized sufficiently to disconnect the line relay 305 and special relay 308 from the line 304, thereby preventing any possibility of the relay 309 being operated to disconnect the line from the connector bank.

The battery current supplied over the line through the connector will flow in the opposite direction from that supplied from the line relay 305 and special relay 308 and therefore, if the subscriber should inadvertently or otherwise operate the key 311 after such a connection has been established and before the receiver is removed from the switch-hook, the polar relay 312 would be energized in such a direction as to operate the relay 333, thereby disconnecting the loud speaking receiver 313 from the line. If the subscriber, upon receiving a ringing signal from the con nector switch, removes his receiver from the switch-hook, the relay 314 will be operated, thereby in turn completing the circuit of the relay 314 and disconnecting both the polar relay 312 and the loud speaker 313 from the line.

Although I have illustrated my invention by a specific circuit arrangement, it will be obvious that other automatic manual exchanges may embody my invention as I do not intend to be limited by the specific illustration except insofar as set forth in the appended claims.

I claim:

1. In a telephone system, a called subscriber's station; a plurality of calling subscribers stations; means for normally permitting two-Way communication between any of said subscriber stations; means including circuit connections for simultaneously connecting any number of said calling subscribers to said called subscriber simultaneously for the broadcast of a program; storing means, and means including said storing means at said called subscribers station automatically responsive to an incoming call for indicating the totalized number of all such calling subscribers during said program.

2. In a telephone system, a called subscribers station; a plurality of calling subscribers stations; means for normally permitting two-way communication between any of said subscriber stations, automatic means including circuit connections for simultaneously connecting any number of said calling subscribers to said called subscriber simultaneously for the broadcast of aprogram; storing means; and means including said storing means at said called subscribers station automatically responsive, to an incoming call for indicating the totalized number of all such calling subscribers during said program.

,3. In. a telephone system, a called subscribers station; a plurality of calling subscribers stations; means for normally permitting two-way communication between any of said subscriber stations, manual means including circuit connections for simultaneously connecting any number of said calling subscribers to saidcalled subscriber simultaneously for the broadcast of a program; storing means; and means including said storing means at said called subscribers station automatically responsive to an incoming call for indicating the totalized number of all such calling subscribers during said program.

4. In a telephone system, a called subscribers station; a plurality of calling subscribers stations; means for normally permitting two-Way communication between any of said subscriber stations, means including circuit connections for simultaneously connecting any number of said calling subscribers to said called subscriber simultaneously for the broadcast of a program; storing means; means including said storing means at said called subscribers station automatically responsive to an incoming call for indicating the number of all such calling subscribers during said program; and means for preventing said calling subscribers from carrying on conversations over said connections during such connection to said called subscriber.

5. In a telephone syste. a called subscribers station; a plurality of calling subscribers stations; means for normally permitting two-way communication between any of said subscriber stations; automatic means including circuit connections for simultaneously connecting any number of said calling subscribers to said called subscriber simultaneously for the broadcast of a program; storing means; means including said storing means at said called subscribers station automatically responsive to anincoming call for indicating the totalized number of all such calling subscribers during said program; and means for preventing said calling subscribers from carrying on conversations over said connections during such connection to said called subscriber.

6. In a telephone system, a called subscribers station; a plurality of calling subscribers stations; means for normally permitting two-way communication between any of said subscriber stations, manual means including circuit connections for simultaneously connecting any num ber of said calling subscribers to said called subscriber simultaneously for the broadcast of a program; storing means; means including said storing means at said called subscribers station automatically responsive to an incoming call for indicating the totalized number of all such calling subscribers during said program; and means for preventing said calling subscribers from carrying on conversations over said connections during such connection to said called subscriber.

7. In a telephone system, a called subscribers station; a plurality of calling subscribers stations; means for normally permitting two-way communication between any of said subscriber stations, means including circuit connections for simultaneously connecting any number of said calling subscribers to said called subscriber simultaneously for the broadcast of a program; storing mean-s; means including said storing means at said called subscribers station automatically responsive to .an incoming call for indicating .the totalized numnections for simultaneously connecting any 5 number of said calling subscribers to said calledsubscriber simultaneously for the broadcast of a program; storing means; means including said storing means at said called subscribers station subscribers automatically responsive to an incoming call for 1,

indicating the totalized number of all such calling subscribers during said program; and means for permitting only one-way communication from the called subscriber to said calling subscribers.

9. In a telephone system, a called subscribers station; a plurality of calling subscribers stations, means for normally permitting two-way communication between any of said subscriber stations, manual means including circuit connections for simultaneously connecting any number of said calling subscribers to said called subscriber simultaneously for the broadcast of a program; storing means; means including said storing means at said called subscribers station automatically responsive to an incoming call for indicating the totalized number of all such calling subscribers during the program, and means for permitting only one-way communication from the called subsoriberto said calling subscribers.

10. In a telephone system, a called subscribers station; a plurality of calling subscribers stations each having a meter; means for normally permitting two-way communication between any of said subscriber stations, means including circuit connections for instantaneously connecting any number of said calling subscribers to said called subscriber simultaneously for the broadcast of a program; storing means; means including said storing means at said called subscribers station automatically responsive to an incoming call for indicating the totalized number of all such calling subscribers during said program; and means for automatically operating the calling subscribers meters a plurality of times to make a special charge for said connection.

11. In a telephone system, a called subscribers station; a plurality of calling subscribers stations each having a meter; means for normally permitting two-way communication between any of said subscriber stations; automatic means including circuit connections for simultaneously connecting any number of said calling subscribers to said called subscriber simultaneously for the broadcast of a program; storing means; means including said storing means at said called subscribers station automatically responsive to an incoming'call for indicating the totalized number of all such calling subscribers during said program; and means for automatically operating the calling subscribers meters a plurality of times to make a special chargeforsaid connection.

12. In a telephone system, a called subscribers station; a plurality of calling subscribers stations each having a meter; means for normally permitting two-way communication between any of said subscriber stations; manual means including circuit connections for simultaneously connecting any number of said calling subscribers to said called subscriber simultaneously for the broadcast of a program; storing means; means including said storing means at said called

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