US1387668A - Call-metering system - Google Patents

Description

F. M. SLOUGH.

CALL METERING SYSTEM.

APPLICATION FILED sEPL2s. 191a.

Patented Aug. 16, 1921.

INVENTOR UNITED STATES PATENT OFFICE.

FRANK M. SLOUGH, OF ROCHESTER, NEW YORK, ASSIGNOR TO THE STROMBERG- ROCHESTER, NEW

YORK, A CORPORATION OF NEW YORK.

CALL-METERING SYSTEM.

Specification of Letters Patent.

Patented Aug. 16, 1921.

Application filed September 26, 1918. Serial No. 255,736.

To all whom it may concern."

Be it known that I, FRANK M. SLOUGH, a citizen of the United States residing at Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Call-Metering Systems, of which the following is a full, clear, concise, and exact description.

My invention relates to a telephone service meter, and its object is to provide an improved organization of circuits and apparatus whereby given connection cannot be registered more than once.

A further object is to provide means whereby after a connection has once been registered, a subsequent attempt to register the same connection will be unavailing, certain safe guards having been provided to prevent re-registration until the entire connection has been taken down and a new connection established.

A further object is to provide a signal operated previous to the response of a called for subscriber when a connection has been established between a calling line and the line of the called subscriber, and to extinguish the said signal when the called subscriber responds.

A further object of my invention is to provide a key individual to a connecting circuit, whereby an operator may control the registration function.

A further object of my invention is to provide means wherein the aforesaid objects are attained in a circuit wherein the regis ter is connected to a limb of the calling line, and in such a system wherein the register circuit associated with the line must be of relatively high resistance.

Other objects of my invention and the inention itself will be more clearly underl the description thereof progresses.

AQLQlIlHg to the figure accompanying this s ecification, at Al show calling subapparatus connected to the limbs of a line L1, by which the calling substation is connected to terminal line apparatus at the central office, the said terminal line apparatus comprising a line relay LR. controlling a line lamp L.L., a cut-off relay CUR, a register REG., a terminal jack for the line J. A called line is shown at L2 terminating in substation apparatus B cennecting the said substation apparatus to the exchange. The line apparatus for both of the lines L1 and L2 may be, and is illustrated as being of the same nature. A line interconnecting link circuit is shown at 0, comprising talking strands for each end of the link circuit terminating at one end in a plug Pl for the answering end and a plug P2 at the calling end of the connecting circuit, the talking strands for both ends being inductively linked by means of the windings of a repeating coil. An operators circuit is shown at 0 adapted to be connected by means of a key K to the talking conductors of the connecting circuit. A. supervisory signal lamp SA. is provided for the answering end of the connecting circuit, a corresponding signal lamp SE. being provided for the calling end of the connecting circuit. Nine relays are provided for the cord connecting circuit illustrated, the magnets for these relays being indicated in the drawing at #1, #2, #3, #4, #5, #6, #7 and #8.

Contact controlling aimatures for the above numbered relays are shown at different points of the figure, being variously placed as a matter of convenience in tracing the described circuits, the armatures being identified with their controlling electromagnets by being referenced with the same numeral as used for indicating the particular controlling magnet for a particular armature. All of the contacts for the said armatures and also the apparatus of the entire system illustrated, is shown in normal unoperated condition.

To make the above perfectly plain, for example, a magnet referenced #4 is shown connected to the lower terminal of the winding 3 of the connecting circuit repeating coil. This magnet carries two armatiu'es, the one being shown at the bottom and in the middle of the figure, the other being shown above and to the left of: the first mentioned armature. It is to be understood. that each of these armatures close their associated contacts simultaneously when the magnet #4 is sutliciently energized by the flow of current through its winding.

The registers for each of the lines shown at REG. for line and at REG. 2 tor the called line are preferably constructed having two windings, one of which is permanently connected in circuit with the terminal of the spring jack J for the calling line and J2 for the called line register, the other being so connected only when the register has fully attracted its armature. The registers may operate their counting members which may be of any well known construction and which are not specifically illustrated but understood, upon the forward stroke of the register armature, or upon the back stroke thereof. The registers operating either way are well known in the art to which this invention appertains.

In the embodiment of my invention illustrated in the drawing, the line registers are incorporated in a well known form of line circuit involving a cut-off relay shown at (1013. having two differential windings one of which, the upper, is permanently con nected to a limb of the line, the other of which is connected through normal. contacts of the relay (10R. to the other limb of the line, the line relay for the line being serially connected in circuit with the second winding. In this line circuitot the art, when current flows from the central office through one of the said windings over the line including the subscribers substation apparatus, returning through the other winding of the cut-off relay Call-t, the two windings being traversed by the same current and being of equal effect upon the armature and being differentially connected, no operation of the armature of the cutofl relay will take place, but the serially connected winding of the line relay LR. will cause it to be operated to light the line lamp. The responding operator inserting an answering plug P1 into the calling line jack J, will upset the balanced. condition existing between the two windings beforementioned by connecting a source of current to the first mentioned permanently connected winding to increase the effect of this permanently connected winding, at the same time producing a shunt upon the second winding, and the relay (3.0.11. will operate to disconnect the second winding and the serially connected line relay from the second line conductor.

In the embodiment of my invention illustrated, I connect the lower and operating winding of the register REG. in serial circuit with the permanently connected upper winding of the relay (10.1%. The register is operated by projecting over the corresponding talking strand 6 of the associated connecting circuit, a current from a source of higher potential than that normally connected to the said strand to traverse the windings of the relay C.O.R-. and of the register REG. which are permanently connected to a talking strand of the line circuit. The register will then attract its armature, closing contacts 7 to connect the upper winding of the register to the talking strand 8 of the line which at the time is connected to the talking strand 6 of the connecting circuit, the closing of the, register contact thus placing the said upper register winding in multiple with the lower winding and serially connected upper winding of the relay C.O.R., the result of this established multiple circuit being that the resistance from the talking conductor 8 of the line to ground will be made very much lower than that previously obtained, and the flow of current from the high potential source will be greatly augmented.

Art the time the marginal relay #8 is operated as before described, the said relay #7 is retired under the control of the said relay #8, and the relay #8 will be operatively locked so as to prevent the reenergization of the said relay #7 while either the answering plug P1 or the calling plug remains in the connected line jacks, thus preventing a reconnection ot the said source of high potential current to the line register circuit. Below the downwardly extending circuit conductors 10, 11 and 12 to which they lead, is shown a ringing trip relay #6, varlous relay contacts, a ringing key #13, a ringing generator #14, and a ringing circuit interrupter #15, together with associated apparatus and conductors, the above mentioned apparatus and conductors operating in connection with ringing relay #5 to perform the function of automatically and periodically ringing the called line subscriber at B, and for removing the ringing current upon the response of the said subscriber.

A brief description of the operation of the circuits illustrated will now be had for a better understanding of the invention:

The subscriber at A calling, establishing the talking bridge of the line by removing his receiver from the hook will operate the line relay LR, causing the display of the line lamp LL. in the usual manner. The operator responding, will make connection with the calling line by inserting the plug P1 into the jack J, and thereby connect the talking strands 8 and 160i the calling line to the talking strands 6 and 17 of the connecting circuit. The differential relay GU11. hitherto Lin-responsive to equal current flowing through both its windings, is now operated by a reinforcing flow of current through a circuit traced as tollows; the said current flowing through the upper winding of the said relay: From the negative pole of the source o1 current, relay winding #1, normal contacts 18 associated with an armature #7A of relay #7, the winding 2 of the repeating coil, talking strand 6 of the connecting circuit, talking strand 8 of the line circuit, upper winding of relay C.O.R., lower operating winding of register REG. to ground. Current from the said source will flow through the said windings in addition to the line current, through the calling substation apparatus and the relay C. O. R. will be operated. lVhcn operated, it will break the circuitof the line relay LR. at contacts 19, and extend the circuit of the talking conductor 16 of the line to the test contact 20 of the jack thereof, for busy tone purposes. The contacts 19 being open, the relay LR. will be retired, retiring the line lamp LL. Current from the above mentioned source of current will not flow through the lower winding of the register in sufficient strength to operate the said register, the said register having a marginal adjustment and being irresponsive to low current strengths.

Current to the calling substation transmitter T will now be supplied over a. circuit traced as follows: from the ground pole of battery, the lower winding of the register, the upper winding of the relay C. O. R, line talking strand 8, substation transmitter T and receiver R, switchhook and contact 21, line talking strand 16, connecting circuit talking strand 17, winding at of the connect ing circuit repeating coil, normal contacts 22 of the relay #7, the winding of relay #2 to the negative pole of the source of current. Current from the said source will flow over the said circuit energizing the re lay #2. Relay #1 of the connecting circuit is also at the time energized over a part of the same circuit, the circuit for relay #1 being traced as follows: from the ground pole of battery, a winding of the register REG, the upper winding of the relay C.O.R., line talking strand 8, connectin circuit talking strand 6, the winding 2 or the connecting circuit repeating coil, normal contacts 18 of the relay #7, the winch ing of the relay #1 to the negative pole of the source of current. Relays #1 and #9 are therefore at the time energized in addition to the relay C.C.R. Relay #2 attracts its armatures, causing the operation of relay #2A which relay is for the purpose of operating relay contacts whenever relay is operated. thus lightening the relay contact load upon the armature of relay #a. Also the introduction of the winding of relay #2A in the circuit provides another path to ground from the tip talking strand to increase the supply of transmitter battery current to the calling substation.

The supervisory signal lamp SA. :for the answering end of the cord circuit will not at this time be operated, because of the presence of the subscribers substation instrument upon the line, thus opening the contacts 23 in its energizing circuit. The operator attending the call in the usual way will operate her listening key K, and will converse with the calling subscriber learning the number of the called line station, connection to which will be made by inserting the calling plug into the jack J2, the listening ke being restored to normal. A circuit will now complete to operate the of? relay C0. of the called line, the cirincluding the winding of the relay 1. and the winding of relay #4, said circuit also inchiding central ollice source of current, the winding #3 of the re ieatiug coil, tip talking st rand ot the connecting circuit, tip talking strand of the called line, and the lower windin oi the called line register REG. 2. Relays l and CC. will be operated. the register however having a marginal adjustment will not be operated. Ringing of the called subscribe:"s station will take place upon the operators depressal of one of the ringing keys provided, such the ringing key 1?: of the connecting circuit. Upon such a doprcssal common end key contacts will he momentarily closed and 6 opened. The cl ire of these contacts will establish a circuit for the winding. oi? ringing relay the said circuit including the central oilicc source ot current; the said circuit may be traced as follows: from the ground le of battery, now closed contacts of relay #4:. normally closed contacts 26 of relay #3, now closed contacts 27 of relay #2A, now closed contacts 28 or? relay #1 77""? the end key spring contacts 2 1, momentarily closed. the winding of the relay #5, the re tancc coil R13. to the n u'cc cl current. Current "mm the said sour 1c will operate the relay and when the said relay will opcratrrel lock \e pole of the 1 c urc of contacts 29 oi the said wlu are bridged across the momenclosed the contacts 30 at the said key to extend the circi :hc rn crater ll. c! the circuit from l 0 ground Wllaltcn natcly through the u' i'upj ol the ringing l now clos c ii 1 oil the relay #5 :22 1 over the r line through rcllcd line fillllfll'l lll'h signal bell till, 'ctuning over the other side ol' the line h n w cl sed contacts 3 3 rd relay h win-inductive r lancc 3G to the \c pole ol the 05" current. ever the ca led l) rc spends by taking his recei' 0 heel; and thus completing a. conduct .c bridge of the line wires, the relay #6 will be operated. the said relay being irresponsire to the 'ignalin g current from the {IGHQ='1Et2l' 14, but

' e to the flow of direct cu"- he central oi'iice source of: current.

.y #6 is thus operated. it-w l cl "s 37 to sho circuit the winding of the lay which will now det nergire breaktit from REG. is now conditioned.

ing its locking contacts 29 and restoring the normal contacts 38 in the sleeve talking strand of thecord circuit. At this point, the registration of the call on the calling subscribers line meter REG. will ordinarily take place provided that the registration key RK. has been previously set.

This registration key may be a locking key and when so constructed may be entirely set, and when so set may be left in this con dition so that the registering will be accomplished automatically without any further attention from the operator or, the key may be made non-locking and in either case may be operated manually by the operator after the two subscribers are in conversational circuit according to the method of operation desired, either method being supplied with the same safe guards and provisions as the other, the circuit operations being alike in both cases.

Assuming that the key RK. has been previously set or is now operated, relay #7 will be operated whenever the circuits are in condition for registration, that is, whenever on a new connection put up by means of the connecting circuit C, both subscribers are operatively connected in conversational circuit, a conditions being that no registration should have already been made during the said conversationalperiod initiated by the response of the called subscriber. At the time of such aresponse and until the registration has taken place, a circuit is completed for the operators register lamp BL, traced as follows: from the negative pole of the source of current through the said register lamp RL, through now closed contacts 39 of the operated register key R.K., normal contacts 40 of the marginal register trip relay #8, through multiply connected contacts l1 and 42 of relays #213. and to the ground pole of the source of current. The lighting of the signal lamp will indicate that an operation by the calling, register At the same time relay #7 operated over a circuit traced as follows: from the ground pole of battery, multiply connected contacts 4C1 and -12 of relays #QA and #4, normal contacts 40 0f relay #8, now closed contacts 39, now closed contacts 43 of relay #3, now closed contacts 44: of relay :ll-QA, winding of relay #7, resistance coil 15, to the negative pole of the source of current. Current from the said source will operate the said relay #:7 to project high potential registering current over the calling line register circuit, as will be later described.

The relay #7 is preferably constructed in acordance with the relay construction set forth in my application, Serial No. 185,636, December 7, 1916, although this is not essen tial in order to carry out the main purposes of my invention but, some such construction is required in order to carry out some of the other objects thereof. T he said application illustrates a relay having a plurality of contact operating armatures, one of the said armatures having a magnetic shielding eifect on the other, this construction causing the relay when energized to operate the shielding armature before operating the shielded armature. Such a structure therefore enables one to have in a single relay structure a fast operating and slow operating contact controlling armature. For the relay #7, the armature $571k is the slow operating armat-ure, the others being relatively fast operating. In this way 1 am enabled to operate the relay #7, to cause the operation of the first or fast armature which will operate contact as to condition the circuits for the application of high potential current and thereafter apply by means of the slow operating armature thesaid high potential register current. The contact at of the relay #7, fast operating, short circuits the winding 2 of the repeating coil, this being done to lessen the click in the connected subscribers receivers, incidental. to the quick fluctuations of current in the talking strands 6 and 8 of the system, absorbing in a. large measure the energy due to such fluctuations which would audibly operate the diaphragm of the receiver of the connected subscriberf The relay being operated, contacts 17 thereof are closed to produce a locking circuit for the relay #7 independent of the contacts 4:3 and 44.: of relays #3 and :tt-ZA respectively, and independent of the contacts 39 of the register key llcii, this locking circuit bridging the said contacts, being for the purpose of preventing the breaking down of the registering condition prior to the actual registration due to possible quick openings of any of the said contacts.

The operation of the key Elli. breaks contacts 48 which normally bridge contacts 18 of relay #7. The fast armature of relay #7 having operated to close contacts 46 and 47 and to open contacts 22, the slow armature will now be operated to break contacts 18 and close contacts 49. The breaking of contacts 18 disconnects the relays #1 and :ttE EA normally bridged to the tip strand 6 of the connecting circuit from the said tip strand, the closing of the contacts 19 extends the high potential current register source H.P. to the said tip strand, and the complete circuit being traced as follows: from the gro und through the said high potential source of current, the positive pole of which is connected to ground, the protecting resistance unit U, now closed contacts 50 of the register key lit-. 51, the shunted operating winding OW. of relay #8 with its non-inductive shunt Nl, now closed contacts 19 of the relay #7, now-closed contacts 16 of relay #7, the talking strand 6 of the connecting circuit talking strand 8 of the calling line circuit, the operating winding of the relay and the operating winding of the registeto ground.

\Vhereas I may operate all the other circuits the system outside of the ringing circuit from a single source of direct current compri ing a storage battery of nerhaps 40 volts, 1 find that in order to properly op erate the registering system of my invention a higher voltage source of current is required to operate the register REG. when the said register is given such an adjustment that it will be irrcsponsive to other sources of current before mentioned, including the 40 volt source and the ringing generator source. I therefore make the voltage of the registering generator ill. considerably higher, a voltage of 90 volts having been found to be quite satisfactory in practical demonstration of a system embodying my invention.

The flow of current over the circuit HP. just described including a winding of the register is therefore of considerable strength and will operate the said register to cause it to fully attract its armature. lVhen the register has fully attracted its armature.contact T ope 'ated thereby ill be closed shunting that portion of the registration circuit just described, which includes a winding each of the register and the cut-off relay (10.18.. reducing the resistance of this portion of the circuit very materially and greatly augmenting the flow of registration current from the source HP. and which flows through the shunted winding Odfi of the marginal registration trip relay #8. it the time the registration current is applied to the tip strand 8 of the line as before described, some of this current momentarily flows over the line and through the calling substation instrument, back over the sleeve side 16 of the line and the sleeve strand 1? of the connectim circuit, repeating coil, winding 4 thereof and, the contacts 22 of relav #l" being open. through contacts 51 of relay the winding of the said relay to the negative pole of the low voltage source of current. Due to the higher voltage of the high potential source of current over the line circuit and through the winding of relay the flow of current is reversed in direction, this reversal momentarily (lo-magnetizing relav and causing relay #2 to retract its zirniatures breaking the contact 51 in its circuit. This circuit being broken at the contacts 51 cannot be re-established, so that the winding of relay #2 is for the present removed from the line circuit and all of the registration current from the high potential source after the opening of the said contacts passes through the register windings alone, and none of it passing over the line. The augmented flow due to the closure of contact 7 of the register as before described, 0perates the marginal relay #8, which w1ll attract its armature breaking contacts 40 and closing contacts 52. The breaking of contacts 40 removes the short circuit normally established about the winding H.\V. of relay #8, which winding is the holding winding, and relay #8 is maintained operative after the breaking of the contacts 40 by current through this winding H.\V., a circuit for the flow of current therethrough being traced as follows: from the ground pole of battery, through the contacts 42 of relay #4, the said winding H.W., key contacts 39 of the key R.K., the signal lamp BL. to the negative pole of the source of current. The armature 9 further advancing to close the contacts 52, the signal lamp is shunted by the resistance coil 45, which is likewise connected to the negative pole of the source of current.

At the time the contacts 52 are closed, relay #7 is short circuited by the said contacts, the short circuit being traced as follows: from a terminal of the winding of relay #7, now closed contacts 47 thereof, now closed contacts 52 of relay #8 to the other terminal of relay #7. Relay #7 now deenergizes to retract its armature and break the contacts 47 in the circuit of its winding, the said short circuit preventing its reoperz tion under any conditions except a complete restoral of the connection to normal. The non-inductive resistance coil NI. about the winding OJV. of relay #8 is of much lower resistance than the winding ORV. in order that the said winding with its noninductive shunt will be as nearly non-inductive as possible, and still permit the winding to operate the relay #8 at the proper time. This in order that arcing at the contacts 49 may be prevented upon the breaking of contacts 49 when the relay #7 retracts its armatures breaking the registration circuit. I find that by so proportioning the non-inductive resistance and the winding 01V. that the arcing otherwise existing at these contacts is so reduced as to be non-objectionable. By the method of control just described for the relays #7 and #8, the operation of the said relays is made positive and the operation of either of these relays is prevented, which operation might otherwise under some conditions cause a re-registration of the calling line meter which, of course, is very undesirable in practice. The relay #7 retracting its armatures, the contacts operated thereby will occupy their normal positions shown in the drawing, the relays #1, #2 and .A are again operated, and register REG. is again restored to its normal position, this armature being completely retracted.

The register fully retracts its armature after a complete operation because of the breaking of contacts 49 of relay #7 interrupting the flow of registration current from the high potential source H.P. The two windings of the register are proportioned in a novel manner whereby I am enabled to achieve a novel result.

When the winding .0. of the register is shunted by the winding SW. thereof, the current flowing through the winding WVO. will of course be considerably reduced. I so wind the two register windings that the energizetion of the register when both windings are effective is substantially the same as when only the winding W.O. is effective, that is, current flowing through the winding S N. will energize the register to a degree determined by its ampere turns, and the two windings are so proportioned. that this particular number of ampere turns under the various conditions of use is substantially equal to the reduction in ampere turns on the energization of the winding ,0, due to the shunting of said winding. Due to these provisions when the contacts #7 of the register close, they will not immediately open again due to the shunt of the winding W0. causing a vibration of the register armature, causing a disagreeable buzzing noise to be heard on the telephone line, and perhaps causing the register to operate improperly. hen the relay #QA again opcrates after the registration period, contacts 41 are again placed in multiple with contacts 4:2, and the holding winding. HJV. of the relay #8 will be jointly controlled by the said contacts of these relays so that until both relays are retired which can only happen when both plugs are withdrawn from the calling and called line jacks, can the relay #8 be restored to condition the registration relay #7 for a second registration.

Vhile I have above described a specific embodiment of my invention, I am. aware that numerous and extensive departures might be made from the embodiment illustrated without departing from the spirit of the invention.

What I claim as my invention is defined in the following claims:

1. In a telephone system, thecombination with a telephone line, of a central office 0011- nection switch, a line meter having a circuit adapted to be completed by said connection switch, the said line meter having contacts adapted to be closed when the said line meter is energized, an operating winding for the saidline meter, a second winding therefor, and adapted to be placed in multiple with the said first winding when the said contacts are closed, a marginal relay and a source of registration current adapted to be connected to the said line meter when a connecting circuit is associated with the said telephone line, by the operation of the said connection switch, an armature for the said marginal relay adapted to be operated when the said line meter contacts are closed, but not operated prior to the closure of the said contacts, means under the control of the said armature to cause the said registration source of current to be dissociated from said line meter when the said armature is operated, and a holding circuit for the said marginal relay including a normally short circuited winding thereof.

2. In a telephone system, the combination with a telephone line, of a central oflice connection switch, a line mete-r having a circuit adapted to be completed by said connection switch, the said line meter having contacts adapted to be closed when the said line meter is energized, an operating winding for the said line meter, a second winding therefor, and adapted to be placed in multiple with the said first winding when the said contacts are closed, a marginal relay and a source of registration current adapted to be connected to the said line meter when a connecting circuit is associated with the said telephone line, by the operation of the said connection switch, an armature for the said marginal relay adapted to be operated when the said line meter contacts are closed, but not operated prior to the closure of the said contacts, means under the control of the said armature to cause the said registration source of current to be dissociated from said line meter when the said armature is operated, and a holding circuit for the said marginal relay including a normally short circuited winding thereof, the said short circuit for the said winding including normal contacts of the said marginal relay.

3. In a telephone system, the combination with a telephone line, of a central oifice connection switch, a line meter having a circuit adapted to be completed by said connection switch, the said line meter having contacts adapted to be closed when the said line meter is energized, an operating winding for the said line meter, a second winding therefor, and adapted to be placed in multiple with the said first winding when the said contacts are closed, a marginal relay and a source of registration current adapted to be connected to the said line meter when a connecting circuit is associated with the said telephone line, by the operation of the said connection switch, an armature for the said marginal relay adapted. to be operated when the said line meter contacts are closed, but not operated prior to the closure of the said con tacts, and means under the control of the said armature to cause the said registration source of current to be dissociated from said line meter when the said armature is operated, said meansincluding normally open contacts of the said marginal relay, the windings of the said register being so proportioned that the magnetic energization thereof is constant regardless of the closure or opening of t 1 said register contacts.

at. In telephone system, the combination with a telephone line, of a central oiiice connection switch, a line meter having a. circuit adapted to completed by said connection switch, the aid line meter having contacts adapted to be closed when the said line meter is energized, an operating winding for the said line meter, a second winding therefor, and adapted to be placed in multiple with the said its; winding when the said contacts are closed, a marginal relay and a source oi registration current adapted to be connected to the said line meter when a connecting circuiit is associated with the said telephone line, by the operation of the said connection si itch, an armature tor the said marginal rel adapted to be operatel when the said line meter contacts are closed, but not operated prior to the closure of the said con tacts, means under the control of the said armature to cause the said registratioi'i source of current 3e disassociated from to said line m "er when the said armature is operated, it. a relatively low resistance non-inductive shunt for tl e operating winding of the sad marginal relay.

In an electfcal metering ystem, the combination with an electromugnetically operated nie'er having an energizing winding, an ener izing circuit including a source oi current for the said winding, a marginal the said ci 'cuit, means to apply relay 101 the said source or" current to the said circuit to operate the said n cter. a contact controller by the said meter and adapted when the meter is rully operated to alter the flow of current in the said energizing circuit to operate the saicr marginal relay. a contact in the said energizing circuit un l r the control of the said marginal relay adapted to open the said energizing circuit when the said marginal rela is operated, and a holding 'd marginal relay adapted operated after an initial to maintain 1 operation.

6. In an electrical metering system, the combination with an electromagnetically operated meter having an energizing winding, an energizing circuit including a source of current for the said winding. a marginal relay for the said circuit, means to apply the said source of current to the said circuit to ope trolled by the s the meter is ieter and adapted when ully operated to alter the {low of current in the said energizing circuit to marginal relay, a contact in operate the said the said energizing circuit under the control of the said marginal relay adapted to open the said energizing circuit when the said marginal relay is operated. a holding circuit for the said marginal relay adapted to maintain it operated after an initial operation, and two windings for the said mar ginal relay, the first winding connected in the said energizing circuit and the second winding in the said holding circuit.

7. In an electrical metering system, the combination with an electromagnetically eperat d meter having an energizing winding, an energizing circuit including a source of current for the said winding, a marginal relay for the said circuit, means to apply the said source oi current to the said circuit to operate the said meter, a contact controlled hy the said meter and adapted when the meter is fully operated to alter the flow of current in the said energizing circuit to opera e the said marginal relay, a contact in the said energizing circuit under the control (it the said marginal relay adapted to open the said energizing circuit when the said marginal relay is operated, a holding circuit for the said marginal relay adapted to maintain it operated after an initial operation, two windings tor the said marginal relay, the first winding connected in the said energizing circuit and the second winding in the said holding circuit, and a relatively low resistance non-inductive resistance unit connected across the terminals of the said first named winding.

In a telephone system, the combination ith a calling telephone line, of a called telephone line, substations -t'or the said lines, a line interconnecting circuit for interconnecting the said lines terminating at each end in connection terminals adapted to be associated with cooperating connection terminals tor the lines when connection is made therewith, a relay associated with each of the said connection terminals, each adapted to be placed under the control of the substation apparatus of the associated line, a call register associated with the calling line and having its energizing circuit carried through one of the said connection terminals, a relay associated with the said line interconnecting circuit having a plurality of armatures, contacts separately controlled by each of the said armatures, one of the said armat-ures being a fast operating armature and the other armature being a relatively slow operating armature, means to energize the said relay under the joint control of both of the said substation controlled relays, means to condition the line interconnecting circuits tor an operation of the said calling line register, the said means including the said contacts operated by the fast operating armature, and means to agply the said source of current to the said register circuit by the contacts operated by the said slow operating armature.

9. In a telephone system, the combination with a telephone line, of a central oifice connect-ion switch having connection terminals connected with the talking strands of the said telephone line, aline meter for the said line connected to one of the said talking strands, the said line meter having contacts adapted to be closed when the said line meter is energized, a marginal relay and a source of registration current adapted to be connected to the said line meter through the said line connection switch terminals when a line interconnecting circuit is associated with the said telephone line, by the operation of the said connection switch, an armature for the said marginal relay adapted to be operated when the said line meter contacts are operated, but not to be operated prior to the closure oft the said contacts, and means under the control of the said arm ature to cause the said registration source oi current to be dissociated from the said line meter when the said armature is operated.

10. In a telephone system, the combination with a telephone line, of a central otlice connection switch having connection terminals connected with the talking strands of the said telephone line, a line meter for the said line connected to one of the said talking strands, the said line meter having contacts adapted to be closed when the said line meter is energized, a marginal relay and a source of registration current adapted to he connected to the said line meter through the said line connection switch terminals when a line interconnecting circuit is associated with the said telephone line, by the operation of the said connection switch, an armature for the said marginal relay adapted to be operated when the said line meter con tacts are operated, but not to be operated prior to the closure of the said contacts,

means under the control of the said armature to cause the said registration source of current to be dissociated from the said line meter when the said. armature is operated, and a holding circuit for the said marginal relay including a normally short circuited winding thereof.

11. In a telephone system, the combination with a telephone line, of a central oiiice connection switch having connection terminals connected with the talking strands oi the said telephone line, a line meter for the said line connected. to one of the talking strands, the sand line meter having contacts adapted to be closed when the said line meter is on ergized, a marginal relay and a source of registration current adapted to be connected to the said line meter through the said line connection switch terminals when a line in terconnecting circuit is associated with the said telephone line, by the operation of the said connection switch, an armature for the said marginal relay adapted to be operated when the said line meter contacts are operated, but not to be operated prior to the closure of the said contacts, means under the control of the said armature to cause the said registration source of current to be dissociated from the said line meter when the said armature is operated, and a holding circuit for the said marginal relay under the control of contacts of the said marginal relay and the said connection switch.

12. In a telephone system, the combination with a telephone line, of a central otfice connection switch having connection terminals connected with the talking strands of the said telephone line, a line meter for the said line connected to one of the said talking strands, the said line meter having contacts adapted to be closed when the said line meter is energized, a marginal relay and a source of registration current adapted to be connected to the said line meter through the said line connection switch terminals when a line interconnecting circuit is associated with the said telephone line, by the operation of the said connection switch, an armature for the said marginal relay adapted to be operated when the said line meter contacts are operated, but not to be operated prior to the closure of the said contacts, means under the control of the said armature to cause the said registration source of current to be dissociated tromthe said line meter when the said armature is operated, and a holding circuit for the said marginal relay including a normally short circuited winding thereof, the other circuit for the said winding including normal contacts for the said marginal relay.

13. In a telephone system, the combination with a telephone line, of a central otfice connection switch having connection terminals connected with the talking strands of the said telephone line, a line meter for the said line cgnnected to one of the said talking strands, the said line meter having contacts adapted to be closed when the said line meter is energized, a marginal relay and a source of registration current adapted to be connected to the said line meter through the said line connection switch terminals when a line interconnecting circuit is associated with the said telephone line, by the operation of the said connection switch, an armature oi the said marginal relay adapted to be operated when the said line meter contacts are operated, but not to be operated prior to the closure of the said contacts, and means un der the control of the said armature to cause the said registration source of current to be dissociated from the said line meter when the said armature is operated, said means including normally open contacts for the said marginal relay.

14. In a telephone system, the combination with a telephone line, of a central oiiice connection switch having connection terminals connected with the talking strands of the said telephone line, a line meter for the said line connected to one of the said talking strands, the said line meter having contacts adapted to be closed when the said line meter is energized, a marginal relay and a source of registration current adapted to be connected to the said line meter through the said line connection switch terminals when a line interconnecting circuit is associated with the said telephone line, by the operation of the said connection switch, an armature for the said marginal relay adapted to be operated when the said line meter contacts are operated, but not to be operated prior to the closure of the said contacts, means under the control of the said armature to cause the said registration source of current to be dissociated from the said line meter when the said armature is operated, an operating winding for the said line meter in the said circuit completed by said connection switch, a second winding therefor and adapted to shunt the said first winding when the said register contacts are operated, the windings of the said register being relatively so proportioned that the magnetic energization of the said register is independent of the closure or opening of said register contacts.

15. In a telephone system, the combina tion of a telephone line, of a central ofiice connection switch having connection terminals connected with the talking strands of the said telephone line, a line meter for the said line connected to one of the said talking strands, the said line meter having contacts adapted to be closed when the said line meter is energized, a marginal relay and a source of registration current adapted to be connected to the said line meter through the said line connection switch terminals when a line interconnecting circuit is associated with the said telephone line, by the operation of the said connection switch, an armature for the said marginal relay adapted to be operated when the said line meter contacts are operated, but not to be operated prior to the closure of the said contacts, means under the control of the said armature to cause the said registration source of current to be dissociated from the said line meter when the said armature is operated, and a relatively low resistance non-inductive shunt for the operating winding of the said marginal relay.

16. In a telephone system, the combination with a calling telephone line, a calling substation receiver for the said line, a connection switch adapted to be associated therewith, including calling and called terminals, a repeating coil inductively linking the said terminals, means to cause an electric change of potential in the said connection circuit, and means including a short circuit of one of the windings of said repeating coil to prevent the said electric changed potential violently operating the diaphragm of the calling substation telephone receiver.

In witness whereof, I hereunto subscribe my name this 19th day of September, A. D.

FRANK M. SLOUGH.

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