US1459863A - Measured-service telephone system - Google Patents

Description

June 26, 1923. $459 3 F. M. SLOUGH MEASURED SERVICE TELEPHONE SYSTEM Filed MaICh 25 1918 INVENTOR Patented June 26, I923. 1

STATES PATENT QFFEQE,

FRANK M. SLOUGH, OF ROCHESTER, NEW YORK, ASSIGNOR TO THE STBOMBERG-CARL- SON TELEPHONE MANUFACTURING COMPANY, OF ROCHESTER, NEW YORK, A COR- PORATION OF NEW YORK.

MEASURED-SERVICE TELEPHONE SYSTEM.

Application filed. March 25, 1918. Serial No. 224,415.

To all whom it may concern:

Be it known that I, FRANK \I. SLoUeH,

a citizen of the United States, and residing at Rochester, in the county of Monroe and 5 State of New York, have invented certain new and useful Improvements in Measured- Service Telephone Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone exchange systems, and more particularly to measured service telephone systems in which a record is kept of the service secured by the subscriber through the exchange, and relates furthermore to facilities provided for the purpose of giving improved service to the subscriber.

It is an object of this invention to provide means to charge subscribers for calls in accordance with the time of day when such calls are made, and in accordance with the time the subscribers telephone is in use.

It is another object of this invention to provide an improved registration apparatus at the exchange and associated with the line apparatus of the subscriber thereat for registering the units proportional to the charge to be made to the subscriber, and it is still another object of this invention to provide registration means at the subscribers station, so that the subscriber may be kept informed at all times as to the charges being made against him.

Other objects of this invention and the invention itself will be apparent as the description thereof progresses.

It has been found in. the operation of telephone exchanges that the load during busy hours of the day is far in excess of that during the remaining hours of the day For instance, in certain exchanges it is found thatlat about 9 oclock in the morning and again at 5 oclock in the evening, there is an abnormal load placed upon the system by the increased number of calls being put through at these times, this on account of the business and social habits of telephone users. During these .short periods which vary in different locations in duration and occurring at different times of the day according to the location and habits of the people living therein, it is necessary to call into use at the telephone exchange an in creased amount of telephone line interconnet-ting apparatus over what is ordinarily required during other times of the day, and the provision of this extra apparatus not only increases the cost of the telephone exchange apparatus,but cuts down the etficlency of operation of the same. This is true whether the exchange is a subscriber operated or a centrally operated exchange.

It is an object of this invention to so apportion a charge made to the subscriber, that it will be to the subscribers monetary interest to make his calls, if possible, occurring at some other than the busy time of day for the telephone exchange, and to limit the conversational period length.

In registering charges against calling, subscribers and telephone exchanges, it is the usual practice to charge the subscriber so much. a call, but this is objectional for the reason that in such a method of charging an injustice is done to the subscribers who use the telephone for only short periods of time, so that in my improved system I so arrange a register at the main office and a subsidiary register at the telephone substa tion, which register units of the charge at certain rates of registration, the rates de pending upon the time of day, and the number of registrations depending therefore upon the time of day and the length of the conversational period.

In my improved system, I positively control the subsidiary subscribers register by the main office subscribers register, so that there will be uniformity of registrations between the two registers.

The objects of this invention and the invention itself will be more clearly understood from a description of the drawing illustrating the embodiment of my invention in a manual or centrally operated telephone system, although many of the objects of my invention may be capable of embodiment in a subscriber operated or so-called automatic telephone system.

Referring to the drawing, at A, I show a calling subscribers substation apparatus, and at B, I show a called subscribers substation apparatus. At C, I show an opera tors connection link circuit illustrated hereother like plugs,

in as a cord circuit. For the line of the subscriber A, I show a line relay Z, controlling a signal lamp Z, a cutoff relay 0 and a substation registration relay r. The contacts of the relay 1 are of the make-before-break type to insure the energization of the supervisory relay so during the transmission of impulses controlling registration. "I also show a central ofiice register at R and a switchboard jack in which the calling subscribers line terminates at'J. The cord circuit C terminates at the call answering end in a switchboard plug P, and at the called subscribers end in a switchboard plug P. An operators set isshown'atO,an'd'adapted by means of switchboard key is to be connected to the talking strandsoi the cord circuit. At S, I showregistra'tion apparatus common to aplurality of cord circuits C, and capable of controlling the operation of registers on,

whatever line such cord circuits maybe connected. For instance, the apparatus S serve the lines of an entire exchange. The apparatus consists of a clock or other timing'apparatus T, which operates contacts s ,at certain intervals, for instance, once an hour; Ilnderthe control of these contacts and operated at such periods as the contacts are operated, is ainotor magnet M for a rotary 'swit'ch SW'which ispropelled from switch contact to switch contact under the control of the'timing apparatus T and the control magnet M, thereby changing the connection 'bety'velen the switch-arm la oi the sWit clitSl/V from one contact of the switch to another according to thetimeot day.

illustrated there are 24 contacts for this switch, one for each hour of the day, and there are furthermore 24 conductors CT, leading from these contacts to interconnecting switch mechanism IS. This interconnecting switch mechanism is herein illus trated as'th e well-known plug switchboard, in which it is possible to interconnect any 0f the vertical circuit conductors CT extending through this switchboard to any of the horizontal conductors H. Any number of the conductors CT may be connected to the same conductor of the group H, as may be desired. Each of the conductors of the group H leads to a magnet, such as mflm mor m Each oi these magnets controlthe connection to a common rate or registration circuit conductor BR, leading to'the' cord circuits of the exchange; One of the registration interruptersI, 1 ,1 I and T is included in circu t 'witlithe rate of registration conductor RR at a time, dependingupon the position of ,tli e'switc-h SW at thetinie and the condition of interconnection orthe switchboard IS, as may be predeterminedby the insertion the interconnecting plug, such for int rs $f s$11 ni t er s y the P sltions occupied the plugs K, and the may The interrupters I, I 1 I and I, have different rates of actuation, revolving for instance. at different rates of speed, so that the connection between the central office source of current BY and the rate of registration do with the registration functions alone will nOt be operated, since it is customary to only charge the originating or calling subscriber for connections put through the switchboard. I

For the supervision of the connection put through the switchboard by means of thein: tel-connecting link circuit C, two signal lamps are provided, SA and SC for the ane swering and the calling ,end of the cord circuit respectively. At 3a, and at so are the re,- spectivesupervisory and ,co ltrolling relays under the control the answered and called subscribers respectively.

At E, is shown a relay performing a func: tion of conditioning the signal lamp SA to make a recall for the calling subscriber, and in addition periormsthe function of separating thetalking strands of the cord circuit, so that the called'subscriber may not hear an ensuing conversation between the recalling subscriber and the operator.

The other apparatus shown in the drawing and the operative relation betweenthe different apparatus therein shown will be more clearly understood from a description of a connection which will be assumed to be made between a calling subscriber at the substation A, and called substation at as follows: A

The subscriber at A removing his receiver from the hook, will close a talking circuit by the closure of the contacts 2 for the substation transmitter 3 and receiver 4 of the substation A, and will close a circuit including the winding of the line relay Z to operate the line lamp Z upon the closure of the contacts 5 of the line relay Z. The circuit of the line relay Z can be traced from the negative pole of battery through the winding source operating the line relay and closing its contacts 5, will operate the line lamp Z, attracting the attention of the operator to the call. The operator will answer the call by inserting the answering plug P of the cord circuit C into the jack J of the line making connection between the talking conductors thereof to the tip and sleeve springs of the jack by the corresponding talking conductors of the cord circuit. tion of the plug into the jack will complete a circuit, including the windings of the cutoff relay 0 of the line, of the local controlling relay 10 of the cord circuit and of a resistance coil 11, together with the central oflice source of current, this circuit being completed by the joining of the contact 12 of the plug to the thimble contact 13 of the jack. Current from the said source will flow over this circuit operating the relays 10 and a, which will thereupon attract relay armatures, the closing of the contacts 14 of the relay 10 preparing a circuit for the answer ing supervisory lamp SA, and the opening of the contacts 9 and 6 of the line cutoff relay 0 opening the circuit of the line relay Z to extinguish the line lamp Z. The answering supervisory lamp SA will not he operated at this time however, because of the presence of the subscriber substation instrument across the limbs of the line operating the supervisory relay 8a, the circuit for this relay including the central office source of current, the tandem windings of the relay 8611,, the tip and ring contacts of the answering switchboard plug P, the contacting tip and ring springs of the jack J of the line, the talking strands of the line leading to the substation instrument A, the circuit being completed thereat through the substation transmitter 3 and the substation register-impedance coil N across which is connected in multiple the substation receiver l in series with the substation condenser 18. Current from the source of current operating thesuervisory relay set, will open the contacts 17 in the circuit of the supervisory lamp SA to prevent its operation.

The operator will now operate the listening key In, closing the contacts 19 and 20 to connect the operators telephone set at O to the talking strands of the cord circuit which are, as has been stated, at the time connected to the talking strands of the line circuit. The operator and subscriber being now in conversational circuit will converse, and the operator will learn the number of the calledfor line, which we will assume in this description is the line containing the substation B. The operator will make connection with the called-for line after making the usual busy test, and the plug P is therefore inserted into the jack J to extend the connection between the calling and called lines by the operation of a ringing key is. A

The inser-.

contact 23 of the plug P and the thimble contact 24 of the jack of the called line, the circuit furthermore including the central oiiice source of current and the winding of the called line cutoff relay 0. Current from the said source will operate the relays 22 and c, the relay 0 opening its contacts 25 and 26 to disconnect the called line relay 27 from the line conductors, and the relay 22 closing its contacts 28, 29 and 60.

At this point it may be stated, that the cutofl' relays 0 and 0 for the lines have two armatures, the one armature having a sensitive adjustment and the other armature an insensitive adjustment, the last-named armature being for the relay 0, that armature which operates the contacts 30, and for the relay 0' that armature operating the contacts 31. These contacts for the two relays will not, at this point in the operation of the circuit, be operated. The operator having restored her listening key to normal, the contacts 15 will again be closed to condition a circuit for the answering supervisory signal SA. The ringing key is having been operated, will again be restored, closing its normal contacts and connecting the windings of the called supervisory relay so, together with the central office source of current in circuit with the called subscribers line to be operated at the moment of response of the called subscriber upon taking 7 his receiver from the hook to close the line circuit of the called line, whereupon the called supervisory relay so will be operated, attracting its armatures, closing its contacts 32, and opening its contacts 33."

Prior to the response of the called-tor subscriber, the called supervisory lamp SC was operated over a circuit traced from the negative pole of the source of current, through the lamp SC, through normal contacts of the relay so, and now closed contacts 29 of the relay 22 to ground pole of the source of current. Upon the breaking of the contacts 33, this signal is extinguished denoting to the operator that the called-for subscriber has responded. At this time the two subscribers are in conversational circuit,

that it is desired by the improved construction herein set forth, to begin to register units of charge against the calling sub scriber.

These units of charge may be for convenience in the register R at the central oflice .1 units and may be for the substation regthe one with the other, and it is at this time the windingof the cutoff relay 0 decreased in resistance by an amount equal to the shunting of the resistance 0011 ll in its circuit. Upon such a shunting. for instance,

by the'operation of the contacts Stet the register relay the contacts 80 will be,

closed, and the adjustment so. made that they will. be again opened upon the opening of the contacts 34:, the operation of these contacts 30 of the relay '0 being adapted to be opened and closed under the control of the contacts 34 the while the contacts 6 and 9 remain opened.

At 1, 1 I 1 and P, are shown interrupters revolving to. produce interruptions of circuit conductors associated with them, each interrupter revolving at a diiierent rate of speed so that each will produce a characteristic rate of circuit interruption. hiieans are provided by theprovision oi contacts 36, 37, 38, 39 and lO for the relays 771, m

m m and m respectively. for including in circuit with the controlling registration conductor RR any one of the circuit inter rupters described having a definite characteristic rate of interruption. Assume -tor the moment, that the relay m alone is operated at the time the circuits involved. are operating as described. Such being the case, the

circuit interrupter I will be i'i'icluded in circuit with the conductor RR, mparting to this circuit interrupter its definite characteristic rate of circuit interruption, whereby.

the circuit-conductor ER will have its circuit interrupted at a definite characteristic rate.

Also included incircuit with the coni'luctor,

ltRarethe central oiiice sourcc of ciu'rent BY, the relay 35 of the cord circuit, the now closed contacts 32 of the relay so, the now closed contacts 41 of the relaysa, and the normally closed contacts 4-2 of the relay E.

Current from theisource BY will operate the.

relay 35 momentarily at the end of definite intervals predetermined by the characteristic rate of interruption of the interrupter I, and each time that the relay 35 is operated, the contacts thereof will be closed to short circuit the resistance coilil in the circuit of the line cutofi relay c, to operate its insensitive armature to close the contacts 3:30 of the relay 0. The contacts 30 are include; in circuit with the central otfice source o'l current am i the register It. The register will be operated at each closure oi the con tacts 30, and the counting mechanism not shown in the drawing but, well understood, will be advanced from one counting position to another at each actuation.

Periodically, and at the end of periods during which the register R has been opened v at a definite predetermined number of times,

for instance ten times, the contacts .45 are momentarily closed upon the next succeeding actuation of the register, a circuit 'thereby being completed during such actuation for the substation register controlling relay 7, including the central office source of current, the circuit being traced :trom the negative pole of the said source, the winding of the relay 1, through contacts 45 of the register mechanism, through contacts 46 atthe central oflice source, through the windings of the cord supervisory relay so, to the conductors t? and d8 of the line leading to the substation register N, and then again closing the circuit but reversing the line conductors 4:7 and with respect to the positive and negative poles oi? the source of current connected to the windings of the supervisory relay so. In other words, the central otlice battery is momentarily reversed with'respect to the substation register N, and this register is adjusted to only op crate when current from the central otiire battery is reversed in direction. Therefore, upon such a reversal the register N at the substation which is magnetically polarized, will operate to indicate to the subscriber that so many charge units, tor instance ten .151; charge units have beenregistered by the master controlling register R at the central oliice. It can be seen thatisince thev number of registrations depend upon the rate of interruptions of the interrupter I, that by operating the relay m instead of the relay m, that a different interrupter, for instance the interrupter I included in circuit with the relay 35, and therefore causing this relay to be actuated at a different rate, for instance, a more rapid rate will cause the registrations of the two registers to be accomplished at a different or correspondingly more rapid rate. Other rates of registration actuations may be accomplished by including the other registers incircuit with the relay 35. The

circuit conductor BB in circuit with which the registrations are adapted to be included,

- switching means to provide for the association oil the diiie rent interrupters in circuit with the conductor RR at different times of the day as may be desired. This apparatus consists of a switchboard IS, by means of which any of the vertical conductors CT may be connected to any of the horizontal conductors H leading to the relays m m etc., to control their operation, and may be of any suitable form, being illustrated as a plug cross-bar switchboard of a well-known form.

The clock mechanism T, is adapted by means of the intervening driving magnet M and a central oflice source of current to step the rotary switch SWV from its position of contact with one of the vertical circuit conductors CT to another from hour to hour, so that in twenty-four hours the rotary switch will have completed a circuit with each one of the vertical conductors CT, each one for an hour. The position of the plug in the switchboard IS obviously determines which relay of the group at to m is to be included during a given hour in circuit with the cen tral source of current, the connection to the ground pole of which is applied to the rotary switch-arm a. For instance, when the rotary switch-arm a makes contact with the contact 50, the relay m is operated and the circuit interrupter I is for an hour associated with the circuit conductor RR. Again during that hour in which the switch-arm a rests upon the contact 51, the relay m is operated to include the circuit conductor 1 in circuit with the conductor HR to control the operation of cord circuit relays, such as 85. Thus, the clock mechanism T shifts the rate of registrations as may be predetermined by the switch plugs on the switchboard IS. The registrations go on during the conversational period as long as the two subscribers have their receivers from the hook without replacement. 1

When the subscribers finish their conversation and either hangs up his receiver, the registration automatically ceases by the opening of the contacts 32 or 4:1 in the cirsuit of the controlling relay 35 of the cord circuit. The called-for subscriber hanging up will give a disconnect signal by the closing of the contacts 33 in the circuit of the signal lamp SC. The calling subscriber retiring, will give a disconnect signal by the deenergization of the supervisory relay sa which will retract its armatures, closing the contacts 61, 62 and 17 and opening the contacts 63 and 41. The closing of the contacts 62 completes a circuit for the looking relay E, the circuit being traced as follows: from the ground pole of the source of current, now closed contacts 60 of the relay 22, normally closed contacts 62 of the relay art, the Winding of the locking relay E to the negative pole of the source of current. Current from the said source flowing over this circuit will operate the locking relay E which will attract its armatures, openlng its contacts 42, 64, 65 and 66, and closing its contacts 67 and 68. The closure of the lastnamed contact 68, completes a locking circuit for the relay E, this circuit extending to the winding of the relay E independent of the contact 62 of the relay set, this looking circuit extending from the negative pole of thesource of current, through the winding of the relay E, through now closed contact 68 thereof, through normally closed contacts 43 of the restoring key if, through normally closed contact 44 located on the ringing key is, through now closed contacts 29 of the relay 22, to the ground pole of the source of current. The closure of the contacts 67 of the relay E and of the contact 61 of the supervisory relay 8a completes a circuit for the signal lamp SA, to cause this signal lamp to give a disconnect signal, this circuit being traced as follows: from the negative pole of the source of current, through the said signal lamp, through the now closed contact 14 of the relay 10, through normally closed contacts 15 located on the listening key is, through now closed contacts 67 of the relay E and the normal contacts 61, now closed, to the ground pole of the source of current. Current from the said source will operate the said disconnect lamp to give a disconnect signal to the operator.

The duty of the operator upon observing this signal, is to perform the actof disconnection by withdrawing the two plugs of the cord circuit of the jacks of the calling and called subscribers. However, it often happens in practice, that the operator being engaged in the work of performing supervisory acts for other connected subscribers and in putting up other connections, may overlook this disconnect signal for the time being. The system of my invention is soarranged that during this interval and prior to the time the operator performs the act of disconnection, the originating connected subscriber may cause the disconnect signal to operate in a characteristic manner so as to give a special signal to the operator, this ordinarily denoting to the operator that the calling subscriber desires another connection, or perhaps may want the called subscriber recalled.

Assuming now that the subscriber A makes such a recall by again taking his receiver from the hook, the supervisory relay so will be again operated, breaking its normal contacts, and again causing its normally opened contacts to be made. The opening of the normal contacts 61 by the supervisory relay sa will interrupt the connection to the ground pole of battery which has maintained the supervisory signal SA operative, and instead will substitute an alternate connection to ground through the flash interrupter F, the circuit including the said interrupter being traced from the ground pole of battery, through the said interrupter,

which iscommon to a plurality of cord cir vcuits, through contacts 28 of the relay 22, through the now closed contacts 68 of the relay 8a, through the contacts 67'0-1 therelay E, through normal contacts 15 on the listening key, through contacts 14: of the relay 10, through the signal lamp SA, to the negativepole of the source of current. Current from the said source will intermittentlqy flow over the said circuit as the interrupter I revolves causing a characteristic flash of the lamp A to attract the attention of the operator to the recall. The operator will attend to the recall by operating her listening key is, which willopen the circuit of the signal lamp SA, by the breaking of the con tacts 15 located on the listening key extin guishing the lamp. The closure of the contacts l9 and 20- will again connect the operators: telephone to the telephone of the calling subscriber at A in conversational circuit; The subscriber at B, that is, the first called subscriber, even though he may have his receiver oii the hook, will not be connected in conversational circuit with the operator or the calling subscriber at this time due to the continued opening of contacts 6'5 and" 66, causing the talking strands in the direction of the called subscriber to be severed. The operator may therefore converse with the subscriber at A to the'exclusion of the subscriber at B, absolute secrecy being maintained as to the subscriber at B.

If the calling subscriber desires a new connection to some other subscribers line'than thesubscribers line having the substation B, be will make known his desire to the operator whowill perform the next necessary connection by withdrawing the plug P of the cord circuitfrom thejack J" of the "former called line and insert it into a jack of the now called line, and perform the ringing function in the manner which has been described for theline having the substation B. If this is done, thel'ocked-up relay E will be restored to normal by the withdrawal of the plug P from the jack J, since such withdrawal causes a deenergization of the relay 22 and an opening ofthe contacts 29 serially included in the locking circuit of the relay E, as has been described, the locking circuit being opened the relay E will be restored to normal position.

If the calling subscriber merely desires the operator to again, ring the called subscriber,

this may be done without withdrawing the plug P from the ack J, and by merely operating the ringing key the restoration of the locked relay E will take place, sincethe contacts 44 serially included in the locking circuit of the locked relay E will be opened upon, every operation of the ringing key is. If the callingv subscriber desires to be reconnected to the called subscriber whom the operator knows to have the telephone off the hook by the efiaced condition of the. signal lamp SA, the relay E may be restored to normal by throwing the un-locking key 7s momentarily to open contacts 43 serially included in the locking circuit of the relay E, as has been described.

It will be observed that the restoration. of the relay E restores the contacts 65 and 6b to operative condition, whereby the talking strands of the cord circuit from the calling to the called ends of the cord circuit, and as the case may be, from calling to called subscribers substations. The restoration oi the relay E also dissociates the flash interrupter 1 from the signal lamp SA by the opening of the contacts 67 of the relay E. T he restoration of the relay E also again conditions the subscribers charge mechanism of the calling line to operateby the closing ofthe contacts 42' of the relay E in the circuit of; the relay 35, which relay may be called the registration relay, and it is. only necessary thereafter that each subscriber has his receiver oil the hook, closing contacts n and 32 of the calling and called supervisory relays to cause the registration to recommence.

Now, if it is assumed that the time of day has arrived when the clock mechanism at T through the intermediate driving magnetM has advanced the switch-wiper a to a position where the relay m is retired and one otthe other relays determined by the position of. the plugs on the switchboard TS is operated, it can be seen that the rate of registration will change depending upon which relay as m m on", m isoperated, and which interrupter therefore as 1 I 1 I, is included in circuit with the relay 35, to control its operation. Both subscribers may. converse, the registration going on automatically, the number of registrations being a function of the length of the time they con-verse and of the time of day when they converse.

The conversation being completed, the

subscribers retiring will operate their dis connect signals in the well-known manner and the connection may be taken down by the operator, in which case all of: the apparatus involved in the connection: is restored to normal position.

WVhat I claim and desire to cover by- United States Letters Patent is defined in the following claimsin which I claim 1, In a telephone system, the combination with a subscribers telephone line, of a register mechanism for the said line located at a main station, of a second register mechanism for the said line located at a substation on the line, and means operative underthe control of the main station registration mechanism to operate-the substation mechanism a fractional number of times the main station mechanism is operated.

2. In a telephone system, the combination will be extended lUl) with a telephone line, of register mechanism associated with the said line, of an operators link circuit for connecting the said line to other telephone lines, timing means, progressively movable switch mechanism operable under the control of said timing means, of a plurality of circuit controllers under the control of the said timing and switch mechanism, whereby the said timing and switch mechanism may select a given. one of the said circuit controllers, and means to cause a selected circuit controller to operate the said line register under the control of apparatus in the said link circuit.

3. In a telephone system, the combination with a telephone line, of register mechanism associated with the said line and located at a main exchange terminal. thereof, an operators link circuit for connecting the said line with other telephone lines, register operating mechanism associated with the said link circuit and adapted to be associated with the said line mechanism when connection is made between the said link circuit and the said line circuit, of a plurality of registration controlling means "for the said registration means, and timing means including a progressively movable non-numerical switch to select a given one or" the said controlling means to control the said registration means.

at. in a telephone system, the combination with a telephone line, of register mechanism associated with a main exchange terminal of the said line, of subsidiary register mechanism located at a substation ot the line, a central exchange mechanism operating at a definite predetermined rate to operate at the said rate the main exchange line register mechanism of the said line, and means associated with the said last-named register mechanism to operate the said subsidiary register mechanism once, when the main exchange line register mechanism has been operated a predetermined number of times.

5. In a telephone system, the combination with a telephone line, of register mechanism associated with a main exchange terminal of the said line, of subsidiary register mechanism located at a substation of the line,

central exchange mechanism operating at a definite predetermined rate to operate at the said rate the main exchange line register mechanism of the said line, means associated with the said last-named register mechanism to operate the said subsidiary register mechanism once, when the main exchange .line register mechanism has been operated a predetermined number of times, and a main exchange switch for varying the rates of registration.

6. In a telephone system, the combination with a telephone line, of register mechanism associated with a main exchange terminal of the said line, of subsidiary register mean-- anisiu located at a substation of the line, a central exchange mechanism operating at a definite redetermined rate to operate at the said rate the main exchange line register mechanism of the said line, means associated with the said last-named register mechanism to operate the said subsidiary register mechanism once, when the main exchange line register mechanism has been operated a predetermined number of times, a main exchange switch for varying the rates of registration, and a clock mechanism controlling the said rate of varying means.

7. In a telephone system, the combination with a plurality of telephone lines, of a plurality of link circuits at a main exchange for interconnecting the said lines, substation telephones for the said lines, substation con trol relays in each of the said link circuits for calling and called interconnected subscribers lines, a register individual to a calling one of said lines, commutators associated with the said link circuits adapted to operate the said register under the control of the said relays, timing means for associating a commutator with said register and means under the control of the calling substation instrument to destroy the control of the said commutator over the said register.

8. In a telephone system, the combination with a telephone line, of main exchange register mechanism for the said line, of subsidiary mechanism at a substation of the said line, a central exchange commutator operating at a definite predetermined rate to operate at the said rate the main exchange line register of the said line, and means associated with the said last-named register to operate the said subsidiary register, the said means causing the registration by the subsidiary register of a fractional part of the number of main exchange register registrations. I

9. In a telephone system, telephone lines, a register mechanism for each line located at the main station, an operators link circuit tor connecting the said line to other telephone lines, a plurality of interrupters tor variably operating the register mechanism of the calling line-and a progressively movable non-munerical switch for selecting a desired interrupter to control said register mechanism.

10. In a telephone system, a plurality of telephone lines, two register mechanisms associated with each telephone line, an operators link circuit for connecting one telephone line to any of the other telephone lines and an interrupter for operating one of said registers in response to each operation of said interrupter, said second register be ing operated in response to a plurality of operations of said first register.

11. In a telephone system, a plurality of telephone lines, polarized register mech anism associated with each telephone Line an operators link circuit for Connecting one 5 telephone line to any o'fthe other telephone lines and: means including a relay individual to the calling line, and operated responsive to the interconnection of the calling. and called telephone lines for reversing current in the calling line.- to operate said register.

in Witness whereof, E hereunto subscribe my name this 23rd day of March, A. D. 1918.

FRANK M.. SLLOUGHF

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