USRE14430E - Hewky hovland - Google Patents

Description

UNITED sTATEs PATENT OFFICE.

HENRY HOVLAND, oF EAST ORANGE, NEW JERSEY, AssIGNon TO AUTOMATIC ELECTRIC COMPANY, 0r CHICAGO, ILLINOIS, A' CORPORATION 01' ILLINOIS.

PARTY-LINE TELEPHONE SYSTEM.

Feb. 5, 1918.

Original No. 1,158,221, dated October 26, .1915, Serial No. 728,811, nled October 31, 1912. Application for i reissue filed August 6, 1917. Serial No. 184,756.

To all who/n t 'may concern.'

Y Be it known that I, Hexer Hovnxso, of East Orange, in the county ot Essex and State of New Jersey. have invented certain new and useful Improvements in Party-.Line Telephone Systems. ot which the following is a specification.

My invention relates to part y-line telcphone systems, and more specitically to an improved mechanism whereby, when the call is from one subscriber to another on the same 'acter such as will ring the hell at the called subscribers station. while the Aother generator selected is ot' a character to ring the bell at the station ot' the calling subscriber. Upon making thc call the calling subscriber automatically operates this ring-.back device to select the desired pair of Vringing gen-v erators, and th'cn replaces his receiver upon the switch hook. The ring-back device then v automatically starts to operate to'alternately throw ringing current ot the two selected frequencies upon the line.l thus alternately sounding the bells at the. calling and called subscribe1"s stations. Upon the response -of the called subscriber thel ringing current is disconnected from the line, and thus the calling subscriber is advised b v the cessation ol? the-ringing of his bell that the called suhscriber' has answered. lle then again removes his receiver from the hookand the, conversation is carried on in the usual manner.

A further object. of my invention is the improved manner in which the release of the ring-back device and the automatic switches employed in establishing the connection is brought about. As I have above pointed out, when the calling subscriber first' replaces his receiver'upon the hook and thus opens the line circuit, the ring-back device is automatically started in operation. When, however,

after the called subscriber has responded and the bridge .is againremeved from rQSS the 'Gn Martin No. 1419 of 1910.

linel by the hanging up ofthe receivers at both the calling and called subscribe-Ns stations, the ring-back device is released.

These and other objects of my invention will be more readily understood by reference 'to theaccompanying drawings, in which 1 only a sutiicient portion thereof-to illustrate fully the inode ol operation of my invention.

In the accompanying drawing I have shown dagrammatically a single polystation subscribefs line, together with its individual switch C at the central otiice. a master switch D, a selector' switch l@ and my in'iproved ring-hack device l". At. B there is shown a battlcrvfor furnishing current for operating the central oliice apparatus and for talking liurposes. Connected to the sub scribers line there are three substations A1. 2 and A3. These substations may bc of an)Y suitable or approved type. Referring to the substation A. each et the substations shown heroin comprises the usual-,receiver 2, transmittel' 3, switch hook-4. ringer 5 and conlthe line, is of the general type of line switches shown in British-patent to R. W. James No. 26,301 of 1906, being of the particular form shown in British patent T. This tine switch, as is well known, comprises a plunger (not shown) which is secured to a sO-called plunger arm `11, which lattermllien,

` attracted by the magnet 12,` causes rsaid plunger to be thrust into one of a plurality of groupsof contact springs, each of which groups represents the terminal of atrunk line leading to a` selector switch E. The line switch also comprises a cut-oli' relay arma'- ture 13 and a line relay armature'lll, 'and its magnet 12 comprises four windingsnamely, a ull-down windin 15, a holding and eutowinding 16,*a line winding 17 and an auxiliary vvc'inding 18. The line switch C is one of a group of similar switches which are all controlled by a common mechanism4 or lmaster switch Din such a manner that the 15 plungers of all the idle switches are always maintained' opposite the terminal of an idle trunk line. 'The mastervswitch D is of the type of master' switches disclosed in said.

i British Patents Nos. 26,301 of 1906 and 1419 .-The selector Eis of the general type of selector switches disclosed in United States Letters Patent No. 815,321, granted March 13, r1906, to Keith, Erickson and Erickson,

being modified, however, as shown in said British Patent No. 1419 of 1910, in order to `operate in a twowire system.- In general, thisiswitch comprises a bank of contacts ar ranged in` rows or levels and which are adapted to be engaged by a set of wipers 20, 21 and 22 which are carried by a vertically .and rotatably movable shaft (not shown), the movements of which are controlled by the so-called vertical and rotary magnets 23 "35, and 24. lThe usual side switch comprising and 43 and 44, which'arewearried upon a rotary shaft and adapted tobe advanced .step

e, by. step over two double vrows of contacts through the medium of a stepping magnet 35. -The magnet 36 Vis va release magnet .50 which, when energized, withdraws a holding pawl from the shaft of the switch and lallows the wipers to be restored to normal po sition by a spring in a well-known manner.

The contact 37, which is included` in the cir-4 455 cuit of' the release magnet, is controlled by y the shaft of the switch so as to be closed only when said Ashaft is rotated one or more steps from its normal position. The operation of l the switch iis controlled by the calling sub' scriber through the medium of a double wound line relay 45. The relays 38 and 39 are relays which denergize slowly. There are provided in the switch F two ringing relays 46 and 46. The apparatus as shown lherein is adapted to be used in connection with a four-party line system, There are therefore shown four ringing current generators R1, R2, R3 and R, 'which are assumed to produce ringing current of four different characters., The ringers 5 of the different 70 substations on'the subscribers line may be arranged in any well-known manner to respond only to the ringing current generated by some particular one of the "generators, Forinstance,"the generator R1 may produce 7 ringi `g current of the proper character to operai the ringer at the substation A1. The generator R2 may operate the ringer at the substation A2; the generator R3 may oper ate the ringer at the substation A3 and the 80 generator R4 may operatethe ringer at the fourth substation A4 (not shown). -The generator R1 is connected with the first three contacts in the upper double row of contacts of the switch F. The generator R2 is'con'- 8a nected to the fourth and tifth contacts of the upper row and to the first contacts of the lowerrow. The generator R3 `is co11 nected tothe sixth contacts of the upper row andto theosecond and fourth contacts of the lower row. The generator .R is connected to the third, ffthand sixth contacts of the lower row. With this arrangement, it will be seen that the wipers ell, 42, 43 and 44 may be set so as to connect any two of the gcnerators desired with the springs of the ring ing relays 46 and 46a. Beneath the selector' switch l1) there is shown an interruptor device H which may be common to a plurality i of frequency Selectors F. This device eoin- 10U prises a pair of interruptor wheels 53 Aand 54 which are driven by means of a motor mag- C and the selector E shown herein are in general well known in the art, and are fully described in thepublication hereinabove referred to, it is not thought-necessary to give a detailed description-of the same herein. 021 In general, the operation of these switches is as follows; Upon the removal of the receiver from therswitch-hook at any of the substations on the line, a bridge is closed across the line through the talking circuit at said substation, whereby an energizing cir- .cuit is closed throughthe line winding 17 of the switch C. The winding 17, upon energizing, attracts the armature 14, whereby a circuit is closed through the pull-down-wind- 4130 At 59 there is 105 K ing 15, which latter operates to attract the cut-ofi` armature 13 and the plunger arm 11.

andallowed the armature 14 to fall back to' open the circuit of the operating winding 15. the operation of the line switch (l causes the master switch Dto advance the plungersof the idle line switches of the group to which the switch C belongs to an idle trunk line.

It is assumedherein that some level of the v 'lirst selector is reserved for reverting call purposes. For this purpose there is connected to the contacts of this level a plu- 'rality of trunk lines, each of which leads to a ring-back device F. VThe calling subscriber, after having obtained connection y as with the selector E, by the removal of his receiver operates his calling device for the digit corresponding to the level of the selectors to which the ring-back devices are connected. This operation of the substation calling device produces a series of momentary interruptions in the circuit of the selector line.relay The operation of the relay 63,.in response to these impulses, causes a series of impulses to be transmitted' through the vertical magnet 23, whereby the Wipers of the selector are raised to a position opposite the level to which the ring-back de- Vvices are connected, after whichV the private magnet 29 causes the side switch to'pass to second position. The rotary magnet 24 is thereupon broughtrinto play and operates in the usual manner to rotate the wipers onto an idle set'of contacts in saidglevel, after which the side switch passes to third position. Upon the engagement of the side switch wipers 25 and 28 of the selector with their third-position contact points, a circuit is closed through the line rela)7 45 of the4 ring-'back device F. This circuit extends from ground G1 through the lower winding'- of. ,said relay, contacts 50a and 50, selector wiper 21, side switch wiper 28, contact 62, thence over the line circuit to and through the calling substation and back over the other side of the line, through theline switch bank contact 61, side switch wiper 25, shaft Wiper 20, contacts 49 and 49a and the upper Winding of the relay 45 to the battery lead 66, thence through the battery B to ground G. The relay 45, upon energizing, closes a circuit extending from ground G2 through the front contact of the spring 67 and relay The closure of the contact 65 upon- 39 to the battery lead 66. The relay 39,

upon energizing, provides a guarding ground potential for the selector private bank contacts of the trunk line leading to the sein all of the selector Switches which have access thereto and through the wiper 22 of the selector E,.side switch wiper. 26, contactl 70 and the relay '31' to the battery lead '66. The relay 39, vupon energizing, also closes a circuit extending from ground Gra-through the front contact of the spring 69 and thence through the relay 72. The relay 72, upon energizing,.opens the contact 73 in the circuit of therelease magnet 36 to prevent the energization of said magnet when the contact 37 is closed upon the first stepof the switch shaft. The calling subscriber must now cause the wipers of the ring-bac'kdevice F to be advanced onto the pairs of contacts which are connected to the two ringing current generators which are adapted to produce ringing current of the proper frevquency for operating the ringers at" the calling and called substations. For instance: If

the subscriber at the substation A1 is calling the subscriber at the substation AL', or vice versa, the wipers 41, 42, 43 and 44 must be advanced onto their first contacts, and therefore into engagement with the terminals of the generators R1 and R2. -If the subscriber at the substation A1 is calling the subscriber at the substation A3, the wipers must be advanced onto .the second contacts and into connection with the generators R1 and R,

etc. In order to advance these wipers to any desired point, the calling subscriber operates his calling` device for a digit which is one less than the number of steps required .for the wipers to reach the desired contacts, and then hangs up his receiver. For instance: Ithas been assumed herein that thersubscriber at the substation A1 is calling the subscriber at the substation A?. The calling subscriber therefore operates his calling de- Vvice for the digit 1, whereby the circuit of the line relay 45 is interrupted once momentarily. The relay 39 being a slow .acting relay does not denergize during the momentary interruption of its circuit bythe den-4 ergization of the relay 45, and therefore the relay 45, upon denergizing transmits an impulse over a circuit extending from ground G2 through the back contact of the spring 67, contact 71,-stepping magnet 35 and the relay 38 in multiple to the battery lead 66. The operation of the relay 38 `at this time is functionless. The magnet 35 operates in. response to this impulse' to advance the wipers 41, 42, 43 and 44 onto the first contacts in their. respective rows. The calling subscriber now replaces his receiver upon the switch-hook, whereby the circuit of the line relay of the ring-back device F is again broken. lThe relay 45,` upon denergizing, again closes the circuit o f the step* ping magnet 35, whereby the wipers 41 42, 43 and 44 are advanced one more step onto thev second contacts in their respective rows. The relay 45, in its dei'iergized position, also breaks the circuit of the relay 39, which in turn denergizes after a short time. After the relay 39 denergizes, the holding circuits for the relay 72 and for the release relay 31 'of the selector are maintained at ther con`- tact 74 of the relay 38, which is energizedy The by the denergization ofthe line relay. circuit of the relay 38, as well as that of the stepping magnet 35, is, of course, broken at the Contact 71- when the relay 39 denergizes; but since the relay 38 is a slow acting relay, it maintains the contact 74 closed until another holding circuit for the relays 72 and 31 canbe closed in the `following manner: Since the relay 38 is energized when the re` lay 39 dencrgizes, a circuit is closed extending from iground G through the back contact of the spring 69, contact 75 oi the relay 38 V and normally closed contact 76 of the relay 77, thence through the relay 7 8 to the battery lead 66. The relay 78, upon. energizing, closes a locking circuit for itself and also one for the relayV 77. t The circuit for the relay 7 7 extends from ground G5 through the contact 79 `and relay 77 to the battery lead The locking circuit` for the relay 7 8 extends from ground G5 through the contact 79, contact 81 of the relay 77, contact 82 of the relay 45 and thence through the .contact 83 and the winding of the relay 78 to the battery lead 66. In this circuit last traced it will be seenwthatthere,ism also a circuit extending from ground G5 through the contacts 79 and 81 tothe circuits of the relays 72 and 31 to maintain them energized after the relay 38 has fallen back and permitted the contact 74 to be opened.' A further result of the energization of the relay 78 -is the closure of a circuit `extending from ground Gr5 through the contact 80, and

thence through the windings of the twol ringing relays 46 `and 46" and through the two windings of the relay to the battery lead 66.y The windings of the relay 60 have l a. comparatively high resistance and do not]- permit sufficient current to 'How through the ringing relays 46 and 46 to cause them to be operatively ever, is energized and by closing the contact 84 completes the circuit of the stepping mag- The magnet 5 5 thereupon begins to rotate the ratchet wheel 56 and interrupter wheels 54 and 53, whereby the contacts- 57 and 58 are alternately closed. Upon the closure of the contact 57 -the lupper winding of the relay 60 isy short-circuited and the ringing relay 46-is operatively the Contact 48' is broken and iinall'y i station A3.

energized.A The relay 60, ho` .u

energized. In the relay 46 the contacts 47 and 48 are preferably' in the nature of follow-up contacts, so that" as the relay is energized the contacts are made and broken in the following sequence: First, the contacts 49- and 50V are broken simultaneously, then the contact 47 is closed, then kie contacts 51 and 52 are closed simultaneously. As the relay denergizes, the contacts are made and broken in. the reverse order-that is, the contactsvl and 52 are broken simul taneously, then the contact 48 is closed, than the contact 47is closed and finally the contacts 50 and 49 are closed simultaneously.

The relay 46L operates in the same Inanner. Upon cnergiaing,.tl1e relay 46 there-y fore first disconnects t'ne line relay ot the ring-back device F froru the line by they opening of the contacts 4S and 50. The closure of the contact 47 then shortcircuits the line, which, however, is without function at this time. The contact 48 is next opened and this short-circuit broken,fthen the contacts 52 and 51 are closed, whereby -the ringing current generator- R3 is con nected with the calling line by way of 'the wipers 43 and 44. The callinglineis therefore supplied with ringing current from the ringing current generator R, which, as lbefore explained, 1s of the proper character to operate` only the ringer at the called-for After the interrupter wheels have advanced far enough to open the con.- tact 57, the ri'ngifngrelayfl denergizes, with the result that after the gencifatmj R3 is disconnected from the line, the line .is then short-circuited. during the time-the contacts 47 and 48 are both closed` and then the short-circuit lis removed `from the line and the connection between the line and the line rel ay of the riugback device is. restored, TheI object in short-circuiting thc line aftertlic ringing current is disconnected therefrom, and-before theconnection with the relafiT 45 is restored, isv toprovide a path for the die charge of the condensers on the calli g line, so thatthey will not causel a momentary energization of the relay 45. After the ringing relay 46 is dei'iergized, the contact lll) 58 is closed by the interrupter and the ringy ing relay 46a is energized to connect the ringing current generator R1`with the calling line. This generator it* furnishes ringing current of the propercharacter for oper ating the ringer at the calling substation A1, The rela s 46 and 46 will continue to be alternate y energized and denergized to alternately ring the bells at the calling and calledl substatons A1 and A until the called subscriber responds by removing his 'receiver frornjthe switch hook. As soon as this occurs, or as 'soon thereafter as `the ringing relay denergizes, if it happens to be energized at the time, the iine reilly 45 again becomes energized and by opening the contact 82 destroys the holding circuit of the relay 78. The relay 77, however, remains energized over a circuit extending from ground G3 through the front Contact of the spring 69 of the relay 39, which latter is again energized upon the energization of the relay' 45, and through the contact 81 and the winding of the relay 77 to the battery lead 66. The relay 78, upon denergizing, permanently breaks the circuits of the ringing relays 46 and 46to prevent further application of ringing current to the line. The calling subscribers bell therefore ceases to ring, which is an indication to him that the called subscriber has answered, and he removes his receiver again and the two subscribers now carry on an uninterrupted conversation, the talking current being supplied through the windings of the line relay 45 over the heavy conductors shown inthe drawing.

The release of the central 'oflice apparatus is brought about by the hangin up of the receivers .at both the calling and the called substations. When the last receiver is hung up the line relay 45 again denergizes. Since the relay 77 is locked up at this time, no'

circuit is closed through the relay 78 by the denergization of the relay 45, and consequently as soon als the relays 38 and 39 dcnergize, the circuit of the relay 38 being closed by the falling back of the relay 45, as heretofore explained, the circuits of the relays 'Tand 31 are broken. The relay 72, upon denergizing, closes the circuit of the release magnet 36 at the contact 73, whereupon said magnet energizes and permits the wipers 41, 42, 43 and 44 to be restored to their normal positions, whereupon the contact 37 'is opened -and the magnet 36 permitted to denergize.

The denergization of the relay 3l at the selector EA completes a circuit extending from ground Gr7 through the back contact of this spring 87, back contact of 'the spring 88, magnet 30 and the contact 89 to the battery lead 66.' The magnet 30, uponenergizing permits the shaft of the selector to be restored to normal position, whereupon the contact 89 is opened and the magnet 30 permitted to denergize. The relay 31, upon denergizing, also opens the circuit of the holding winding 16 of the line switch C at the Contact 64 and the line switch is permitted to release also.

,l It will thus be seen that I have devised a very efficient mechanism for making reverting calls. The calling subscriber has merely to operate hisdial to properly operatc the ring-back device in order to select the two desired ringing generators, and then, upon replacing his receiver upon the hook, his bell is sounded to advise him of the fact that the called subscriber is being signaled, and the cessation of this-signal I advises him of the fact that" the called subscriber has answered. I believe that I am the first one to devise a system in which'4 two kindsof ringing .current are sent back over the calling liney in order to operate.,-

the calling signal at both the calling and the' called subscribers stations, Likewise, I believe that I am the lirst to devise a system in which the opening of the bridge across the calling line at one time is operative to start the ringing operation, and at another time is operative to cause the release of theconnection.- 1

-lVhile I have chosen toillustrate my invention in connection with one particular embodiment of the same, it is, ofcourse, to be understood that I do not wish to be limited to the exact construction shown and described.

What I claim as my invention is 1. In a telephone system, a party-line, a'

ring-back apparatus for enabling one party i to call another on the same line, means for two of said generators, and means forthen alternately transmitting the current from said two selected generators over said line.

3. In a telephone system,a party-line, a

plurality of ringing generators for supplying ringing current of different characters, a step-by-step apparatus for selecting any two of said generators, and means'for alternately supplying current from* said `selected generators to Said line.

4.In a telephone system, a party-line, a; plurality of ringing generators for supplying ringing current of'di'erent characters, a step-by-step ring-back apparatus, means for connecting said line with said apparatus, means controlled by the calling subscriber for operating said ring-back apparatus to select any two of said ringing generators, and means for then alternately connecting said selected ringing generators with the line.

5. In a.v telephone system, a party-linda ring-back apparatus for enabling one party to call another on the same line, and means controlled by said ring-back apparatus for transmit-ting two kinds of ringing current back yover -said line to operate lthe calling signal a boul the calling and called sub.v

` cluding a selector switch. for extending a connection from said line to said ring-back f.; ing ofthe calling subscribers receiver upon the switch-hook for alternately transmitting stations on said line.

6. In 'a telephone system, a party-line, a ring-back a paratus for enabling one party to call anotiier on the same line, a plurality of ringing current generators, said ringbaekfapparatus comprising a pair of Wipers, means to operate said wipers to connect each of said wipers with any one of said ringing current generators, and means to alternately connect said wipers with said line.

7. In a telephone system, a party-line, a

ring-back a paratus for enabling one party to call anot er on thesame line, a plurality of ringing current generators, said ring- Aback apparatus comprising two pairs of wipers, means for connecting one of said pairs with any one of said ringing generators, means for connecting the other pair with--iany of the remaining generators, and means for then alternately connecting said pairs of Wipers with said line. x

v 8. In a telephone system,.a party-line, a ring-back a paratus for enabling one party to-call anot er on the same line, a plurality of ringinggenerators of diii'erent characteristics, said ring-back apparatus including a plurality of pairs of Wipers, means controlled Aby the calling subscriber to connect pairs of4 wipers with the rin 1ng one of said .generator o a characteristic correspon in to the signal at the calling substation and for connecting the other pair of wipers with the ringing generator of a characteristic corresponding to the called substation, and means for then alternately connecting said pairs of wipers with said line.

9.A In al telephone system, a party-line, a ring-back a paratus'or enabling one party to-eall anot er on the saine line, means inapparatus, a plurality ofsources of. ringing current, means controlled by said ringackapparatus for selecting any two o said Sources, and meansy controlled by the replaccurrent from said twov selected generators over said line. 4

10. In a telephone system, a party-line, a ring-back apparatus for enabling one party to call another on the saine line, a bridge across said line, means for opening said bridge to cause said ring-back apparatus to operate to send ringing current on the line while the bridge is open and means for opening said bridge at another time to cause the release of said apparatus.

11. In a telephone system, a arty-line,

, a ring-back apparatus for .ena ling one party to call another on the saine line, means i including a selector switchA for extending a connection `troni said line to said ring-back apparatusna' bridge on said line controlled by the switch-hook at the caliing substation, means controlled by 'said ring-back appa-- ratus for transmitting ringing current over said line to signal the called subscriber, means controlled by the opening of said bridge before the called subscriber has answered for starting said ringback appa# ratus' in operation to send ringing current on the 'line While the bridge is open land means controlled by the opening of said bridge after the called subscriber has Aanswered for controlling the release of saidr connection.

l2. In a telephone system, a party-line, a

ringbaek apparatus for enabling one party to call another on the saine line, a plurality of sources of ringing current, means controlled bysaid ring-back apparatus for se- -lecting two of said ringing generators of i1 character Aadapted to'operate the signal at the calling and called substations on said line, a bridge on said line,I means `controlled by the opening of said bridge before the called subscriber has responded for operating said ring-back apparatus, and means controlled" by the opening of said'bridge after tlieealled subscriber has responded'for releasing said4 connection. 1 r

13. In atelephone system, a party-line,

la ring-back apparatus for enabling one party to, call another on the saine line, means Y including a selector `switch for extending a connection from said line to said ringback apparatus, a bridge'on said line controlled by the switch-hook *at thel calling .y substation, means controlled bysaid ringback apparatus for transmitting ringing current over said line to signal the called subscriber, means controlled by the opening Vof said bridge at one point before the called subscriber has answered for starting said ring-back apparatus in'operation to send ringing current on the line while the bridge is open, and; ans controlled bythe opening of said bridge at the same point after the called subscriber has answered forcen-V trollng the release of; said connection.

t 14. In a telephone system, a line, a sec ond line, means for connecting said irst and second lines, a plurality of signals operatively asso'eiatedwith said first line, an automatic switch for said second line, asignaling circuit for each 'signal under the cntrol of said switch, means for supplying signaling current to said circuits and aninipulse sender for operating said automatic switch over said second line, to apply signaling current to said first line, for oper# atingboth said signals while the firstv and` second lines are connected. f 15. In a telephone system, a line, a second line, a pair of "signals for said' first line, means for connecting the "lines, a signaling Acircuit for` eachsignal, means for supplying y signaling current to said signaling .circuits iscl w ile the two lines are'connected.

16. In a telephone system, aline, a second line, a pair of signals for said first line, means forconnectng the lines, a signaling .circuit 'for each signal, means for supplying signaling current to said signaling circuits,

automatic means for associating said signaling circuits with the connected 'circuit while the two lines are connected and an impulse Sender for controlling said automatic means over' the second line for the purpose set forth. y

17. In a telephone system a line', a second line, a plurality of signals for said first line, means for connecting' the two lines, a y signaling circuit for each signal, means for.v supplying'signaling currentv to said circuits and automatic means forV selecting an two of said circuits and for associating t e selected. signalin circuits with the connected ,circuit 'whilet e said two line circuits are connected.

18. In a telephone system, a line, a second line, a plurality of signals for said first line, means for connecting the two lines, a

signaling circuit for each signal, means fory supplying signaling current to said circuits, automatic means for selecting any two of -said circuits and for associating the selected signalin circuits with the connected circu-it whi e the vsaid two lines are connected, and an impulse sender for controlling said automatic means over the* second line for the purpose set forth.

19. In' a telephone s stem, a line a second line, a pair of signas for said first line, means for connecting the lines, a signaling circuit for each signal, means forsupplying signaling current to said signalingcircuits,

^ and automatic means for associating said signaling circuits with the connected circuit wliileithc two lines are, connected, said automatic means having equipment for control-- lin said signalingl circuits for operating sai signals while the first and second lines are connected.

20. In a telephone system, a line, a second line, a pair of signals for said first line, means for connecting the lines, a signaling circuit for eacli signal, means for' supplying signaling current to said si aling circuits, automatic means for associating said sigi'ialing'circuits with the connected circuit while the two lines are connected, and an impulse sender for controlling said automatic means over the'second line for the purpose set forth, said automatic means having equipment for controllin said signaling circuits for operating sai signals while the and automatic means -for associating said i signaling. circuits with the connected circuit while the two lines are connected, said auto-A matic means having equipment for control ling said signaling circuits for operating said signals alternately while the firstand second lines are connected.

22. In a telephone system, a line, a second line, a pair of signals for said first line, means for connecting the lines, a signaling circuit for each signal, means for supplying signalin current to said signaling circuits, automatic means for associating said signaling 'circuits with the connected circuit while the two lines are connected, and au impulse sender for controlling said automatic means over the second line for the purpose set forth,` said automatic means having equipment for co'ntrolling said signaling circuits for'operating said signals alternately while Vthe first and second lines are connected.

23 In a telephone system, a line, a second line, a plurality of signals for said first line, means for connecting the two lines, a signaling circuit for each signal, means for supplying signaling current to said circuit, and automatic means for selecting anv two of said'circuits and for associating the selected signaling circuits with the connected circuit while the said two lines are connected, said automatic means having equipment for controllin for operating `the corresponding signals.

y 24. In a telephone system, a line, a second line, a plurality Iof signals for said first line,

,. means for connecting the two lines, a signaling circuit for each signal, means for supplying signaling .current to said circuits, automatic means for selecting any two of said circuits and for associating the selected signaling circuits with the connected circuit while the said two lines are connected, and an impulse sender for controlling said automaticvmeans over the second line foi-,the

the selected signaling circuits i purpose set forth, said automatic means having equipment for controlling the selected signaling circuits for operating the correspending signals.

' In a telephone system, a line, a second y line, a plurality of signals for said first line,

means for connecting the two lines, a signaling circuit for each signal, means for supplying signaling current to said circuits, and

`automatic meansn for selecting any two of said circuits and vfor associating the selected lsignaling circuits with the connected circuit while the said two lines are connected, said .automatic means having equipment for controlling the selected signaling circuitsl for operating the corresponding Vsignals alternately.

26. In a telephone system, a line, a second line, a plurality of signals for said first line,

` matic means for selecting any 'two of said circuits and for associating the electric signaling circuits with the connected circuit while the said two vlines are connected, and an impulse sender for controlling said 'automatic means over the second line for the purpose set forth, said automatic means having equipment for controlling the selected signaling circuits for operating the corresponding signals alternately.

Q7. In a telephone system, a line, a second line, a plurality of signals for said first line, means t'or connecting the two lines, a signaling ci rcuit for each signal, means for supplying signaling current tosaid circuits and automatic means for selecting a plurality of said signalin circuits and for associating the selected signaling circuits with the connected circuit 'while the said two lines are connected. 1 'Y 28. VIn atelephone system, a line, a second line, a plurality of signals for said first line, means for connecting the two lines, a signaling circuit for each signal, means for supplying signaling current to said circuits, and automatic means for selecting a plurality of said signaling circuits and for associating the selected signaling circuits' with the coni nected circuit while'the said two lines are connected, and an impulse sender for controlling said automatic means over the sect ond line for the purpose set forth.

29. In a telephone system, a line, a second line, a plurality of signals for said first line, means for connecting the two lines, a signaling circuit for each signal, means for supplying signaling current to said circuits, and automatic means for selecting a plurality of said-signaling circuits and for associating the selected signaling circuits with the connected circuit while the said two lines are connected, said automatic means .having first andsecond lines are connected.-

30. In a-telephone system, a line, a Vsecond line, a plurality of signals for said first line, means for connecting the two lines, a signaling circuit for each signal, means for supmatic means having equipment for control* ling said signaling circuits for operating lsaid signals alternately while the first and second lines are connected.

31. In a telephone system,a line, a second line, a plurality of signals for said first line, means for connecting the two lines, a signaling circuit for each signal,'means for supplying signaling lcurrent to said circuits, and automatic means for selecting a plu- 7o rality ot said signaling circuits and for associating theV selected signaling'circuits with the'connected circuit while the said two lines are connected, and animpulse sender for controlling said automatic means over the Vsecond line for the purpose sot forth, said automatic means having equipment for ycontrolling-the selected signaling circuits for operating the corresponding signals. 32; In a telephone system, a line, a secgo ond line, a plurality of signals for said :ir'st line, means for connecting the two lines, a signaling circuit for each` signal, means for supplying signaling current to said circuits, and automatic means for selecting a 35 plurality of said signaling circuits and for associating the selected signaling circuits with the connected circuit while the said two klines are connected, and an impulse sender for controlling said automatic means over the second line for the purpose set forth, vSaid automatic means havingv equipment for controlling the selected signaling circuits for operating the corresponding signals alternately. 95 33. In a telephone' system, a party line, a trunk line, an automatic switch forcennectingl the two, a selective signaling mechanism, means controlled overthe two sides of said line in series for conne the operation thereof, and means effective equipment for controlling said signaling circuits for operating said signals while theV plying signaling current to saidcircuits, and automatic meansl for selecting a plurality of 'ing said connection for during the` signaling operation to maintain said switch in operated position independent of said party line. 4

34. In a telephone system, a line, a plurality of subscribersstations in bridge of said line, a trunk line, an automatic switch for connecting the two, a selectivel vsignaling mechanism accessible to said trunk line, means controllable from one of said stations over the two sides of said line in series for operating said mechanism to signal another one of said stations, and means effective during said signaling operation for maintain.- ing said switch in voperated position independent of said first station.

35. In a telephone system, a plurality of subscribers stations, each station having a signal responsive to a diii'erent kind of cur- 120 rent, a line for said station, a trunk line, an automatic switch lfor connecting the two lines, sources of signaling currents of different -kinds, means controllablefrom one of said stations over the-two sides of said line in series iorconnecting` said trunk line with any of said sources, and means effective durmaintaining said switch in operated position independent of f said stations. ist

cting said trunk 100 'line with said mechanism and for initiating 36. In a telephone system, a line, a trunk line, a selective mechanism havlng a plurality of operating stages, automatic switch- Ying mechanisms' for connecting said line with said mechanism via said trunk line, holding circuits for said switching mechanism, a battery for supplying current, means dependent upon direct current flow in said line for maintaining said holding circuits, and means effective during one of the operating stages of said mechanism for maintaining said holding circuits independent for temporarily maintaining said holdingV circuits. Y

38. In a telephone system, a line, a trunk lim, a selective mechanism, automatic switching mechanisms for connecting said line with said mechanism via said trunk line, holding circuits for said switching mechanisms, a battery for supplying current, means dependent upon direct current How in said line for maintaining said hold-l ing circuits, means made eii'ective -in response to interruption of current flow in said line for temporarily maintainingr said holding circuits, and means actuated in response to renewed current flow in said line whereby said second means is prevented from responding to the next interruption of said current.

n 39. In a telephone system, a line, a trunk line, an automatic switch for connecting the two, a second automatic switch for said 1 trunk line, other lines accessible to said second switch, a selective mechanism having a. plurality of operating stages'also accessible ing current, restoring means for said switches normally responsive to prolongedinterruption of' current flow in said irst line, and means whereby after a connection has been established from said first line to said mechanism said restoring means is made irresponsive to current interruption in said iirst line during one of said operating stages.

Signed by me at -New York, New York courity, New York, this 24th day of July, 191

HENRY HoyL'AND 'to said second switch, a battery for supply-

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