US1834393A - Telephone exchange system - Google Patents

Description

3 I c. B. FOWLER 1,834,393

TELEPHONE EXCHANGE SYSTEM Filed Feb. 12, 1950 /Nl EN7'O/? C. B. FOWLER Its objects are to effect economy inthe use.

i the subscriber against falsecharges andrto' otherwise improve thQOPQIltlOll oftelephone Patented Dec. 1, 1931 UNITED STATES m@E-mjomc i v CLARENCE B. FOWLER, or UE NS VILLAG -NEW YoRK, AssIGNo 'TO- BELL rELE V PHONE LABORATORIES, INCORPORATED, F NEW Y RK, N ."Y.,V A CORPORATION OF NEW YORK TELEPHONE EXCHANGE s sirEM Application filed February 12,1930. Serial No; 427,675;

in which the service charge is based on the duration of conversation.

of the central olfice equipment, to. safeguard systems.

1) Service charging systems have been sug-;

gested in which a source of meter operating current, wlnch is periodically reversed by a timing device, is connected at the central office to the subscribers. llne during the con versational period to cause successivejactuations of the meter; In order to safeguard.

the subscriber against false operation of his meter due to momentary openings of the line, it has been proposed to introduce a tune delay after the called subscriber answers and before the meteribegins to operate. delay is effected by means of interrupter driven contacts individual to thecord cir cuits.

According to my invention a considerableeconomy is effected and animprovement' is secured over these prior systems by means of a time delay mechanism which is common, to a large number of cords or connecting circuits.

Thisinvention has been shown in the ac,' companying drawing in which it has been incorporated in a cord circuit well known in the art.: A calling subscribers line and a called subscribers line have alsobeen shown in diagrammatic form and equipped with service meters. 1 f V The description of a connection by means of this cord circuitfrom acalling subscriber to a called subscriber will nowfibe made.

When the operator inserts plug 2 of cord circuit A into jack 8 ofa calling subscribers llne 4, in response to an lncoming call, a C11- cuit for lighting lamp 1O is-clos'ed and the lower left-hand Winding of repeating coil 7 windingof relay. 5, over the subscribers loop,

throughthe plug 2'and jack 3, upper left- This hand of repeating coil 7, leftehand armature and baclrcontact of relay 6 to ground, Theoperation of relay 5 closes an obvious shunt circuit for the supervisory lamp 10, to battery through a common interrupter 11. This; circuit is alternately closed and opened by the'interrupter to cause lamp-1O to be intermittently lighted and extinguished. The operator in response to this signal actuates the talkinglrey. 12 for the connection. of hertelephone set. across the tip and ring conductors of thefcord toj ascertainthe number of the desired subscriber.. The operation of key 12 also causes the operat on of relay 13 over-an obvious circuit through the left-hand winding of this relay. Relay 13 provides a locki-ngcircuit for itself through its righthand Winding under control of the supervisory relay 5 and disconnects the interrupter from the lamp 1O which-is extinguished due .to the shunt path to battery established at the inner left hand armature and-front contact of relay'18.

When the operator receives the number of the wanted subscriber she imay complete the connection to this subscribers line 15 loyinserting plug 16 into jack 17. Thesupervisory lamp 18 is thereby lighted over the sleeve circuit established through plug 16, and jack 1']. The desired subscriber may 'now be rung in the; usual manner through the operation of a ringing key not shown andwhen this subscriber answersthe callthe supervisory relay 2-0 is operated through the vsubsc'rilrxers loopin the usual manner. Relay 20 in operating establishes a shunt circuit for lamp 18, which is thereby extinguished and also closes: a circuit for the operation of relay 21 from battery, armature and front contactofrelay, 20, left hand armature and back contact of relay Winding of relay 2l, resistance 23, sleeve terminals of plug 16 and jack 17 to ground. it Q r, l Relay 21 in operating established a connection from ground at the outer contacts: of the left armature of relay 6, left-hand armature and front contactof relay 21 to one side of relay 24. Relay 2 4: will now operateas soon as thecircuit through its make-before-break contactsis completed tobattery over a com.- t-

interrupter is connected to the circuit of relay 6 two seconds after the connection from the live segment of the interrupter 25 is opened. The connection to battery through interrupter 26 causes relay'6 to operate over its right-hand winding as the ground connection for the other s1de of this winding 1s completed at the right-hand armature and front eontact of relay 21. Relay 6 provides a lacking circuit for itself under control of relay 21 independent of the interrupter 26 from battery through its outer right-hand armature and front contact. Relay 6 also opens the circuit for relay 24: so that it releases after re-- lay 6 is operated, but relay 24k is made slow to release so as not to open the circuit from interrupter 26 too soon or before relay 6 has closed its locking circuit.

In case now, for example, relays 20 and 21 had been operated momentarily and released between the operation of relay 2 1 and the closure of the connection through interrupter 26 for the operation of relay 6, relay 2% would have released and consequently the operation of relay 6 during this cycle of interruptions by the interrupters 25 and 26 would have been prevented. Such a momentary operation of relays 20 and 21 may be caused by the called party momentarily operating his switchhook or by the cord being connected to a so-called busy-back circuit or for any other reason. False operations of relay 6 are thus prevented under these circumstances, without interference with the eventual operation of relay 6 when conditions are normal. The operation of relay 6 opens the circuit for relay 24: and disconnects the normal talking battery from the tip and ring conductors of the cord and connects these conductors to the meter operating and talking battery 29. The polarity of this battery is reversed at periodic intervals under control of interrupter 30 and relay 31 and will, as is wellknown in the art, cause the periodic operation of the meter 32 of the calling subscribers line. It should be noted that during the interval between break and make of the contacts on relay 6 to substitute batteries a connection to battery and ground through resistance 33 is maintained by relay 2a which is made slow to release for this purpose. In this manner a gradual change in the battery supply is caused and excessive click in the calling subscribers receiver is thereby prevented.

lNhen the called partly disconnects,supervisory relay 20 is released causing the release of relay 21 which in turn causes the release of relay 6 if the called party has already replaced his receiver on the switchhook. 111 case, however, that the calling party still has his receiver oil the hook, relay 6 will be held operated through its left-hand winding as long as timing battery is connected through this winding by the operation of relay 81. The circuit in this case will extend from battery, upper, armature and front contact of relay 31, inner left-hand contacts, winding of relay 6, outer left hand armature and front contact of relay 18 to ground through the sleeve terminals or plug 2 and jack 3. When relay 31 releases and this connection is changed to ground, relay 6 will release. *y insuring the release of relay 6 at this interval, a click in the calling subscribers receiver is prevented and any operation of relay 21 by the called subscriber momentarily operating his switchhook cannot cause a false operation of the service meter l i hen the. calling party hangs up his receiver, relays 5 and 13 are released, thus removing tne shunt for lamp 10 which is now lighted through the sleeve circuit. In case the'calling party should recall by operating his switchhook, relay 5 would be reoperated and-cause the supervisory lamp 10 to be alternately lighted and extinguished. T he o erator would then answer this ca l by the operation of the talking key 12 and cause relay 13 to operate to again shunt the lamp 10 previouslydescribed.

Tn case'the desired subscribers line is a free call line, the operator operates the nocharge key 3 1. The operation of this key causes the operation of relay 22 which looks under control of the sleeve circuit, the resistanceof this winding replacing the resistance 35 in the sleeve circuit. The operation of relay 22 ope s at the left-hand armature and back contact the circuit for relay 21, and thus prevents its operation when the called subscribed answers. As relay 21 is not operated, relay 6 cannot operate and the no anal talking current supply cannot therefore be changed to the timing battery sup ply and no charge made on the meter 32 for this connection.

it should be understood that while the in vention has been only illustrated in connection with one type of circuit it may readily be applied to other circuits without departure from the spirit thereof.

W hat is claimed is:

1. in a telephone system, calling lines and called lines, meters for said calling lines, a plurality of connecting circuits for interconnecting calling lines and called lines for conversation, a source of current for supplying the calling lines, means controlled by a called partyfor connecting said source to a calling line, means for changingthe flow of current from said source to cause the operation of a calling subscribers meter, and contactmeans common to said connecting circuits for in-- troducing a delay between the time the called subscriber answers and the time when the meter operating means'is connected to the calling line.

2. In a telephone system, calling lines, called lines, meters for said lines, connecting circuits for interconnecting calling lineswith called lines, means controlled by a called party for operating the meter or a calling party, and meanscommon to a plurality of connecting circuits for introducing a delay between the time the called party answers the call and the meter operatingmeans becomes eitective.

8. In a telephone system, calling lines, called lines, meters for said lines, a plurality of connecting circuits for connecting calling lines with called lines, means controlled by a called party for operating the meter of the calling party, and a series of interrupte-rs common to a plurality of connecting circuits for introducing a delay in the control by the called party of the meter operating means until a certain period has elapsed after the called party has answered the call.

4. In a telephone system, calling lines, called lines, meters for said lines, a plurality of connecting circuits for connecting calling lines with called lines, means for operating the meter of the called line when a connect-ion tain interval'after the operation of said third v mentioned relay.

7 In a telephone system, calling lines,

called lines, meters for said lines, connecting circuits for interconnecting calling lines with called lines, means for operating the meter of a callingline when a connection is established, a relay responsive to the establishing of a connection, a second relay for controlling the meter operating means, a third relay, means for operating said third mentioned relay in response to the operation of said first mentioned relay, means responsiveto the operation of said third mentioned relay for operating said second mentioned .relay a certain interval after the operation of'said third mentioned relay, and means for maintaining said'second mentioned relay operated under control of said first mentioned relay.

In witness whereof, I hereunto subscribe my name this 10th day of February, .1930. CLARENCE B. FOWLER.

is established, a relay responsive to the estab lishing of a connection, a second relay for controlling the meter operating means, and

means responsive to the operation of the first relay for actuating the second relay when a predetermined period of time has elapsed after the actuation of the first relay;

5. In a telephone system, calling lines,

called lines, meters for said lines, a plurality of connecting circuits for connecting calling lines with called lines, means for operating the meter of a calling line when a connection is established, a relay responsive to the establishing of a connection, a second relay for controlling the meter operating means, interrupters common to a plurality of connecting circuits, and means controlled by said interrupters and the first relay for actuating the second relay when a predetermined period of time has elapsed after the operation of said first relay if said relay has been maintained continuously operated during this period. 6. In a telephone system, calling lines, called lines, meters for said lines, connecting circuits for interconnecting calling lines with called lines, meansfor operating the meter of a calling line when a connection is established, a relay responsive to the establishing of a connection, a second relay for controlling the meter operating means, a third relay, means for operating said third mentioned relay in response to the operation of the first

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