US1216534A - Automatic telephone system. - Google Patents

Description

G. A. YANOCHGWSKI a. H. E. HERSHEY.

Au'rommc TELEPHUNE SYSTEM.

` APPLICATION FILED NOV. 28. 1913. "X u 1,216,534, `utentd Bel). 20, 1917.

2 SHEETS-SHEET` 1.

G. A. YANCHOWSKI (IL E. HEFSHEY.

AUTOMATIC, TELEPHONE SYSTEN.

APPLICATION FILED NOV. 28, 1913.

Patented Feb.20,1917.

wy QM@ www @JM N L Y i M@ @W MH UNITED STATES PATENT OFFICE.

GEORGE A.`YANOCHOWsKI, OF CHICAGO, ILLINOIS, AND HA aRY E. HERSHEY, OF c WHITEWATER, KANSAS, AssIGNOEs To AUTOMATIC ELnCTRIC COMPANY, o1 CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS,

AUTOMATIC TELEPHONE SYSTEM.

Application led November 28, 1913.

. Zeus of the United States of America, :ind

residents of Chicago, Cook county, Illinois,

Aand Whitewater,` Butler county,.Kansas, re-

spectively, have invented certainnew and useful Improvements in Automatic Telephone Systems, of which the following is a specification.

()ur invention relates to improvements in automatic telephone systems, and has for its object the provision of means for auto maticall y switching a connection to an operator in case any one of the switches employed in establishing the connection lands on a trunk which is out of order.

In the accompanying drawings we have illustrated our invention in connection with an automatic telephone system employing 'line switches, selectors, repeaters and connectors ot' well-known types, and have shown h'ow the connection will be automatically switched to an" operators position, first, if the selector strikes a trunk which is open between the selector and the repeater;

` second, it the trunk is open between the rei `cases not `only where the` subscriber-s line has become accidentally open, but also 1n` peater and the next succeeding switch; and, third, il thc connector lands on an open, line. This last feature 1s particularly useful 1n cases where a substation has been disconnected. Heretofore, in such cases,it has been customary to provide special means for switching the connection fromV such a disconnected line to an operators board in order that the ope 'ator can inform the calling subscriber that the telephone of the desired called subscriber has been disconnected. By our invention, however, such switching o't' the connection is accomplished automatically.

Referring to the drawings, Figures 1. and 2 show a complete` connection between a. calling substation A and a called substation A inra system embodying the principles ot' our invention. i

Fig. 3 is a modified arrange-mcnt'of a portion of the circuits.

The substation A and the apparatus shown in Fig. 1. are assumed to be located in. a branch exchange, while the apparatus Specication of Letters Patent.

Patented Feb. 20, 1917.

Serial No. 803,4 26.

shown in Fig. 2 is assumed to belong to the l main exchange. rIhe connection shown is extended through tl e subscribers individual Vswitch C and the selector E at the branch exchange and through the repeater F, which latter 1s lncluded 1.1.' atrunk line leading to the man1 exchange` f1'om.whence the connection extends thr )ugh the connector H to the called substation. The selector E in the branch exchajng e, besides having access to trunk lines leading to the main exchange, is also 'assumed to lave access to connectors in its own exchange for the purpose of corupleting connection i' Yith the branch exchange subscribers. It will be -clearly understood by those versed ir the art that so-called selector switches n' ay be inserted between the main oilice terminal of the trunk line and the connector l-I, thesaid selectors to be similar to the olie shown at E. At I is shown an operatois set, together with a lamp associated Wit l1 a key, the same being assumed to ,be mounted on a complaint or trouble desk. y

yT he substation A shown herein may be of any suitable or appl oved type and comprises the usual receiver l, transmitter 3, ringer 4 and condenser 5. Being an automatic substation itis also p1 ovided with an impulse transmitter or ealliiig device, which is represented herein by a pair of impulse springs (i and T and an impl lse wheel 8, which latter is assumed to be controlled through the` medium ot' a fingei hole* dia] (not shown) in such a manner trat the impulse springs (i and 7 may be i'iomenta'rily separated af number of times corresponding to each digit of the number to bt called.

The subscriber-s individual switch C is of the general typ: of subscriliers switch shown in British pa 'Lent to R. W. James No. 26,301 of 1906, beiI g, however, of the particular type disclosed in British patent to T. G. Martin No. 1419 of 1910. This line switch comprises, umong other details, a plunger not shown) attached to the end of a so-called plunger arm 24. which is controlled by the magjnet 150. The magnet 159 comprises four I rindingns, i'iamcly. a pulldown Winding 19, a cuto` or holding winding 27, a line winding 1l and an auxiliary 8 idle switches in position to engage the terthe windings 19 andv 27 is separate from that of the windings 11 and 20. The windinv 19 operates both the plungeriarm 24 and the armature 25, while the winding 27 set of springs is shown, each line switch is provided with a plurality of such sets, each set forming the terminal of atrunk line leading to a first selector switch E. Each trunk line is connected in multiplel with :'he corresponding springs of all the line switches of the group which is controlled by the master switch D. The switch C is 'controlled by the subscriber through the medium of the line winding 11, as will hereinafter be more fully explained.

Themaster switch D is of the same general type as that disclosed in British Patent No. 26,301 0151906, referred to above, being, however, of the particular type disclosed in lsaid British Patent No. 1419 of 1910. The

function of the master switch, as is well known, is to maintain the plungers of all minal of an idle trunk line.

The first selector switch E is of the general type of selector switch disclosed in United States Letters Patent No. 815,321, granted March 13, 1906, to Keith, Erickson and Erickson, except that the circuits are modified to adapt the `switch to operate in a system in whlch it is controlled by impulses delivered over two sides of the line in sries. Among other details, the selector E comprises a bank of contacts arranged in horizontal rows or levels, which contacts are adapted to be engaged by a set of wipers 63, 59 and 64 carried upon a shaft (not shown) which has a vertical movement controlled by the vertical magnet 50 and a rotary movement controlled by the rotary magnet 55. The operations of the various parts of the switch are controlled through the medium of the double-wound line relay 32. The usual side switch comprising the wipers 51 and 60 is controlled by the private magnet 54 in the usual and well-known manner. Means for permitting the switch to be restored to normal position are provided in the release magnet 143, which, upon energizing, withdraws the retaining pawls from the shaft. The springs 52 close only when the switch shaft has been raised one or more steps from its lowest position. The

relays 40 andA 49 are slow actingthat is,

they denergize slowly after their energizing circuits are broken.

The repeater F'comprises a combination of relays which are for the purpose of receiving impulses from the calling substation and repeating thenrover the trunk conductors 84 and 86 to the connector Hin the main exchange. These relays are controlled directly by means of the dolible-wound line relay 65. The relays 74, 85 and 96 are slow actingthat is, they denergize slowly after theirenergizing circuits are broken.

The connector switch H is of the same general type ot' connector switch as that disclosed in United States Letters Patent No. 815,176, granted March 13, 1906, to Keith, Erickson and Erickson, the circuits, however, being modified to adapt the switch to Operate ina system in which the central oiice apparatus is controlled by impulses delivered over two sides of the line in series. Like the selector the connector is provided with a shaft (not shown) carrying the Vline relay 81 is connected with the line through the reversing springs of a so-called back-bridge relay 134, through the winding of which latter relay the called line is pro- ,vided with talking current. The ringing relay 125 is the means through which ringing currentl is applied to the called line.

At Q is shown a busy signaling machine which provides a busy signal, said busy signal being applied to the calling line through the .medium of the busy relay 145 in case the called line is in use. The substation shown at A and the line switch C are similarl in all respects to the substation A and the line switch C.

For the purpose of supplying battery current for operating the apparatus at different exchanges and for talking purposes, there are shown throughout the drawings -batteries B and B having one terminal grounded at G and G. At R is shown a ringing current generator for supplying ringing current to the called line.

A general description of the apparatus having been given, it will now be explained how a connectionis extended from a calling substation A to a called substation A. We will assume the number of the substation A to be 222. Since the automatic switching apparatus disclosed herein is in general well known in the art and is described in the publications herein referred to, its operation will be explained in a more or less general manner.

Upon the removal of .the receiver from the switch-hook at the substation A preparatory to making a call, an energizing circuit is is thereupon energized. The calling sub scriber now operates his calling device forV the first digit 2 of the called number, whereby the substation impulse springs 6 and 7 are operated twice momentarily, each time breaking the circuit of the selector line relay 32. The relay of theselector being slow acting does not denergizey during the momentary interruptions of its circuit by the lline relay 32 and consequently, each time the latter relay denergizes, an impulse is transmitted over the circuit extending from ground G3 through the springs 38 and 48, springs and 46, relay 49, vertical magnet and the side switc wiper 51 (in first position) to battery B. hevrtical magnet receives two impulses over the circuit and. operates to raise the switchshaft and wipers two steps to a position opposite the second row or level of bank contacts. The off-normal springs 52-close as soon as the shaft is raised one step, but the circuit of the release magnet 143 still remains open at the springs 45 and 47. The relay 49, which is g included in circuit with the verticall magnet,

vas

lcv

is energized'by the rst impulse, but being a slow actin relay does not allow its armature to fallv ack until after the last impulse has been delivered` In its energized position the relay 49 closes a circuit from ground G through the springs 53 and th/e private ma net 54 to battery B. This circuit is broen when the relay 49 denergizes after the last impulse has been delivered to the vertical magnet, the breaking of said circuit causing the private magnet 54 to dee'nergize, thus permitting. the side switch to pass to second position.

In passing from first to second position the side switch wiper `51 disconnects the battery from the vertical magnet 50 and closes a circuit through the rotary magnet 55. The circuit extends from ground G' through the interrupter springs 56, rotary magnet 55 and the side switch wiper 51 (in second position) to battery B. The rotary magnet 55 will then continue to operate in a manner `similar to that of a buzzer' to rotate the wipers step by step as long as the side switch remains in second position. As soon as the rotary magnet energizes the first time, a circuit is closed from ground G6 through the contact point 57, armature 58 and the .private magnet 54 to battery B. The private magnet 54 isenergized over this circuit and is again denergized when the rotary magnet 55 denergizes after having rotated the wipers the first step provided the first trunk line upon whic 1 the Selector wipers are rotated is idle. It the trunk is busy, however, the private wiper 59 finds the contact which it engages proveded with a guarding ground potential. A new circuit is then closed through the private magnet 54 extending from said grounded contact through the wiper 59, side switch wiper (S0 (in second position) and the private magnet 54 to battery B. Ther( fore the private magnet 54 does not dener gize when the rotary magnet armature falls back and the side switch is locked in seconl position. The rotary magnet 55 then continues to advance the wipers step by step until the contacts of an idle trunk are reached, whereupon the private magnet denel gizes, permitting the side switch to pass to third position and thus break the circl it of the rotary magnet 55. When the side :avitch wiper 51 reaches third position, a circ lit is closed from ground Gf through the sp1 `ings 41, springs 61 of the relay 62, relay 35 and the side switch wiper 5l (in third position) to battery B. It will be seen that tlie relay 62 will not be euer gized at this th 1e on account oi being shunted by ground 3*.' The relay 35, upon energizing, operates to disconnect the line relay 32 from the` line and extend the connection through the wipers 63 and`64 to the repeater F. When the circuit is thus extended to the 'epeater, the line relay` G5 is energized ovel a circuit extending from ground G7 thro ugh the lower winding of the line relay 65, springs 66 and G7, wiper (i4, springs 68 anc 34, springs 31 and 30, line conductor 15 to and through the substation A,-line conductor 16, springs 28 and 29,

71 and the upper winding of the line rel-.1y to battery B. The line relay 65, upon energizing, clones a circuit from ground G" through the sp' 'ings 72 and 73 and the relay 74 to battery l5. The rela-y 74, upon energizing, provides a new circuit for the relay 35 of the selector E and the cut-off winding 27 of the line switch C for maintaining the relay 35 and the cut-off coil 27 energized after their original circuit is broken by the denergization of the slow acting relay 40. 'l'his circuit extends from ground G through the s1'. rings 75 and 7G, contact 78, wiper 59 and he side switch wiper 60 (in third position), at which point the circuit divides, one I: art continuing through the springs 61 of the relay 62 and the relay 35 topbattcry B. The other -branch extends from the side switch wiper 6() (in third position) through the springs 42 and 43 and the cut-off coi 27 of the line switch (l to battery B. Tie circuit also divides at the spring 43 and the conductor 44 connects ground to the connector private bank contacts which a:e associated with the line springs 36 and (39, wiper b63, springs 70 and switch C. A The relay 62 does not pull up at this time due to the fact that it is shunted out by ground G9.' The trunk leading to the repeater F is also protected from seizure over any of its multiple contacts by a guarding potential extending from ground G9 to the private bank contact 78 and the multiples'thereof. Another result of the energization of the relay 74 is the closure of -a circuit from ground Gl through the springs 75 and 77 and the left-hand winding of the relay 79 to battery B. The relay79 is so constructed and adjusted that it cannot be operatively energized by one winding alone, but requires the combined energization of both its windings to cause it to attract its armature. The engagement of the springs 80, upon the energization of the repeater Iline relay 65, closes a circuit, through the line relay 81 of the connector H, said circuit extending from ground G1 through the lower winding of the relay 81, springs 82 and 83, over the trunk conductor 81, through the springs 80, relay, 85, righthand winding of the relay 79, trunk conductor 86, springs 8,7 and 88 and the upper winding of the line relay 81 to battery B. Although both windings of the relay 79 of the repeater now carry current, the relay is not operated because the current flows through the two windings'in opposite directions. It will be seen that the energization of the relay 85 causes the springs 8 9 to be separated, thus keeping the circuit of the relay 90,0pen. The energization of the line relay 81 of the connector serves to close a circuit through the slow acting relay v91. This circuit extends from ground G11 through the springs 92 and 93 and the relay 91 to battery B.

The apparatus is now in position for the reception of impulses for the second digit 2. The line relay 65 of the repeater F is denergized twice by the impulses for this digit, each time breaking the circuit of the connector line relay 81 at the springs 80. The relay 74 of the repeater being slow acting does not denergize between impulses. Consequently, each time the line relay 65 deenergizes it also c loses a circuit from ground GB through the springs 72 and 94, springs 95 and the relay 96 to battery B. The relay 96 iS energized by the first impulse and remains in its energized position until after the last impulse has been delivered. In its energized position the relay 96 disconnects the condensers 97 and 98 from fthe trunk lines 86 and 84 and short-circuits the right-hand winding of the relay 79 and the relay 85 and thus removes their resistance from the cir.- cuit of the connector line relay 81 while it is operating. The relay 96, upon energizing, also opens the springs 99 to prevent the circuit of the relay v90 from being closed when.

the relay 85 denergizes, due to being shortingiof its circuit by the line relay of the repeater, a circuit is closed from ground G11 through the springs 92 and 104, springs 105 and 106 (the slow acting relay 91 remaining energized between impulses), relay 107, vertical magnet 108 and the side switch wi r 109 (in first position) to battery B. he vertical magnet 108 is energized twice over this circuit and operates to raise the shaft wipe-rs two steps. The slow acting relay 107 is energized in series with the vertical magnet'108 and does not denergize until after the last impulse is delivered. Upon energizing, the relay 107 closes a `circuit from ground G12 through the springs 110 and 111 and the privateJ magnet 112 to battery B. When this circuit is broken after the last vertical impulse has been delivered to the vertical magnet 108, the private ma'gnet 112 denergizes and the side switch passes to second position. By this action the side switch wiper 109 transfers the battery connection from the vertical magnet 108 to the. rotary magnet 113. When the calling device 4 is operated for the last digit, the repeater I4` operates inthe same manner as for the previous digit. Each time'the connector line relay 81 denergizes in response to the impulses, a circuit is closed from ground G1' through the springs 92 and 104, springs 105 and 106, relay 107, springs 114, rotary magnet 113 and the sideswitch wiper 109 (in second position) to battery B. The rotary magnet 113 is energized twice over this circuit and operates to rotate the wipers onto the contacts of the desired line. The relay 107 operates in the same manner asfor the previous digit to close the circuit of 'the private magnet 112, while the rotary magnet is operating. If the called line yis idle, the private magnet 112 denergizes when its circuit is broken by the relay 107 after the last impulse is delivered to they rotary magnet- 113 and the side switch passes to third position, completing the connection with the called line through the side switch wipers 11.) and 116,--shaft wipers 117,and 118 and conductors 119 and 120. The movement of the side switch wiper 121 to third position provides a guarding potential` for the conconnector ilis reversed in direction.

. this circuit includes the interrupter 124, the

relay 125, is energized intermittently, cach time operating to close a signaling circuit from one terminal of the generator R through the springs 126 and 127, line wiper 117, conductor 119, springs 128, line conductor 16', condenser 5', ringer 4', line con- `ductor 15', conductor 120, line wiper ,118.v

springs 129 and 130 and the relay 131 to the other side of the generator. ln addition to ringing the bell at thel substation A', the generator current also energizes the relay 131, causing it to separate the springs 132 andthus keeping the circuit of the relay 1553 open` The purpose of this relay 133 will be hereinafter more fully described. The relay 133 is made slow acting, e., slow to deenergize after its circuit is broken, and likewise slow to energize upon its circuit being iliade, so that it will not energize duringl the instant between the time that ground (1 is placed upon its circuit by the interrupter 124 and the time that its circuit is broken by the springs of the relay 131, due to the 4generator current being projected on the line. Then the called subscriber removes his receiver, the calling substation is provided with talking current through the windings of the back-bridge relay 134, which relay, upon energizing. closes the circuit of the ringing cut-oil' relay 167, said circuit extending from ground (im through the side. switch wiper 121 (in-third position), springs 136 and the relay 167 to battery B'. The relay 167, upon energizing. interrupts the cir cuit of the ringing relay 125 at the springs 133i and closes a locking circuit for itself through its own springs independent of the springs 136 of the back-bridge relay 134. lt may be mentioned here that in addition to the above. the relay 167 also opens the springs 1,37, thus permanently opening the. circuit of the relay 1253. further result of the energization of the back-bridge relay 134 upon the response o1 the called subscriber is the shifting ol' the springs 13H and 139, which transposes the connections between the. windings oi the relay Sl. and the trunk conductors S4 and H6. whereby the ciirrent in the' trunk between lhe repeater l*` and the rlhis reversal of the current causes the two windings ol the relay 71) of the repeater F to assist each other, whereby the relay itselfjs energized and in turn operated to reverse the direction of the current to the calling substation.

After the con versation is completed, the connection is released by the hanging up of the receiver at toe calling substation in the t'ollouiingr maniu r: lVhen the receiverat the substation A is --estored to the switch-hook, the separation ot' the .hook-switch springs destroys the energizing circuit of the repeater line relay 65, which, upon denergizing, breaks the circuit of the relay S1. The linel relay 81 of 111e connector, upon denergizing, breaks the circuit of the relay 91, which in turn dei nergizes and closes the circuit of the release magnet 140. This circuit extends from ground (in through the springs 92 and 104, spi-ir gs 105 and 141, off-normal springs 142 and :he released magnet 140 to battery B'. The release magnet 140, upon energizing, oper.l tes to release the connector` whereupoi its own circuit is broken at the. onorm il springs 142 when the in the line leading switchshaft reach its lowest position. The

relay 85 of the reneater F being slow acting will not deinergizc immediately upon its circuit being broken at the springs S0. but will remain energized a length of time `sutlicient for the rela] 74 to denergize and remove ground 'from the spring 76, so that when the relay Sa does deiinergize, allowing' the springs 89 to rome into contact, the circuit of the relay 9h will be open at the s ring 76. When the relay 74 of the repeater 1% deenergizes it brealls the circuit of the relay 35,01: the. selector E and also of the cut-oil' winding of the. line. switch C. A circuit is now formed from ground G through the relay 62 and the n klay 35 to battery B. The` resistance of the relays is such that the relay 62 becomes energized, but the relay 35 deinergizes` closing the circuit of the release magnet 143 from grouml G through the springs 38 and 48. springs 45 and. 47, springs 144. olf-normal sltrings 52 and the release magnet 143 to battery B. The release magnet 143. upon energizing, operates to release the selector. wherfnpon its own circuit is' broken at the oil'- normal springs when the switch shaft r1 achesits lowest position. .\t the same time a circuit is formed from grouiid (}"".throug i the relay 62, springs 61, springs 42 and 43 unl thecut-off`coil 27 to battery l, rlhe iesistance. of the coils is such that the cu-oti` `coil 27 deiinergizes, thereby allowing tie plunger arm 24 to return to normal. lt will be seen'that as Soon as theswtches and 1C are released by their release. magnets 2i and 143 the circuit 0f the relay 62 is also opened and the said relay in turn deenergizes. i

lf, when the connector switch Wi rs come in contact witi the called line, this line is busy. then there will be'the usual guardling potentional upon the connector private' bank contact,A Upcn lthe private wiper en.-

ies

' lay 40 and then, after gagi-ng this guarding potential, a busy signal will be. sent back to the calling subscriber from the busy machine Q in the well-known manner. The calling subscriber, upon receiving the busy signal, hangs the receiver upon the hook, thereby releasing the connection in themanner above described.

A general description of the operation of the system having been given, the feature of our invention will now be explained whereby, should a' subscriber -in making a call meet with aftrunk or line which is out of qrder, the'. said subscriber will be automatically connected with a trouble or com-y plaint operator.

The first case to be considered is that in which the shaft wipers of the selector E come to rest upon a set of contacts having an opening in either the positive trunk, the negative trunk, the release trunk or combinations .of the same. Under any of the above conditions the connection from ground G" in the repeater F to the private wiper 59 will be broken. If the release trunk itself is broken, this, of course, breaks this ground connection, while if either the positive or negative trunk is broken, the circuit` or' the. line relay 65 of the repeater will bc broken and the relay 71 will not be energized to connect ground G to the private wiper 5f). As before pointed out, the relay 62 is first short-circuited through the ground connection (l controlled by the reconnection is established with the repeater. this relay 62 is short-circlntcd by the ground connection through the prlvate wiper 59. Therefore,

when there is no such ground on the private wiper 5S), due to thc trunk being open, then as soon as the relay l() falls back, in the. manner previously described, ground is removed froni the spring 41, the relay 62 will no longer be shunted out and a. circuit will be closed from ground G15 through the relay 62. relay 35 and the side switch wiper 51 to battery l. The' resistance of the relays is such that the relay 62 energizes, while the relay 35 deinergizes. The energization. of the relav 62 closes a circuit from ground Gf'through the springs' 152. lamp 15+ and the springs 153 to battery `B. The dcncr` gizat'ion of the relay 35 again connects the liuc relay 32 with theV substation A, which relay 32 therefore cnergizes and again closes the circuit ot' the relay 40, whereby ground is again placed upon the spring 41. thus affording a. holding circuit for the cut-off coil 27 of the line switch C. The plunger of the line switch (l is not withdrawn from the bank springs during the period of time that ground G* is broken for the following reason: W'hen ground (l is removed, a second holding ground for the cut-oli coil 27 of the line Switch C is provided from ground G15 through the relay 62, springs 61, springs 42 and '43 and the cut-off' coil 27 to battery B. However, when the relay 62 energizes, the springs 61 are separated, leaving the cut-off coil 27 without a holding ground. The cut-ofi coil 27 therefore denergizes, but the. armature 25 being a light armature and carrying heavy spring tension falls back before the plunger arm 21 has overcome its inertia. The arma,- ture 25, upon falling back` again places the line relay 11 in the circuit of the substation A. The receiver at the substation A being removed at this time causes a flow of current through the line relay 11. This line relayll, upon pulling up, closes a eircuit through the pull-in winding 19,'which attracts the armature 25, again breaking the circuit of the line relay 11. This buzzing action will keep up. without the plunger being removed from the. bank` until the ground is again connected from G* to again energize the cut-oil'l winding 27,`which then holds the armature 25 in an operated position.4 The ground G* atthis time does not afi'ord a holding circuit for therelay 35 on account of the springs 61 being opened by the relay 62. The complaint operator, upon seeing the lamp 154 lighted, throws the key 156 to the right, thereby opening the circuit. of the lamp ll and bridging the secondary other induction coil in series with her receiver across the line conductors of the selector E. The operator can now converse with the subscriber at the substa` tion A and inform him that the trunk is out of order. Also., it will readily be seen that. should the subscriber hang up his receiver, the selector E will not be released on account of the secondary winding of the operator`s induction coil being bridged across the line conductors of the selector E until the key 156 is restored. This is of value in that the operator can hold the connection up until the attendant at the automatic exchange has located the trunk which is in trouble.

A modified arrangement for obtaining the above result is shown in Fig. 3, in which are shown a number of relays which may be embodied in a selector, such as the selector The lsame reference numbers are used in Fig. 3 to indicate like parts in Fig.v 1, except that the prime mark is added in each instance. In this modification a slow acting relay 165 has been added, its circuit being controlled by the springs 166 of the relay 35. The conductor from the spring 42" passes through the springs 162 and 163 and from thence to the spring 61. When the relay 35 becomes energized, due to ground from G, vin a manner similar to that described in connection with Fig. 1. a circuit is closed through the relay 165, which relay, upon energizing` places ground from G" through the springs 164 and 162 to the spring 42', which affords a holding circuit for the cut-off winding 27 of the line switch C. The spring 162 of the relay 165 is ad'usted to make Contact with thespring 1M efore it breaks contact with the spring 163. Now

when a holding ground fails to come back from the switch ahead, and when the ground is .removedtrom the spring 41', the relay GQ is no longer shunted out and the relay 35 falls back and the relay 62 pulls up, as abore explained in connection with Fig. 1. 'llie relay lt'i being slow acting will not denergize immediately upon its` circuit being broken, but will continue to hold the ground-tiJ upon the spring 42' for an iiistant, by which time the line relay 32 will again have become energized and in so'doingr close the circuit ot' the relay Jft), which will again place ground t'roni tit' upon the springs -tl' to again atl'ord a holding circuit tor the cut-otl winding :2T ot' the liiie switch when the relay ltii dciinergizes. ln this way the buzzing action of the liiie switch in Fig. 'l'is prevented.

Ye will next consider the case in which the selector ll comes to rest upon the coi1 tacts of a repeater I" whose trunk to the distantlcxchange is out ot' order` either by reason of being' short-eiieuited. or the positive'ti'unk open. or the negative trunk open or the negatire trunk grounded. or combinations of the above. l'nder any ot' the above conditionsl the current from the line relay ot' the switch ahead will l'ail to llow through the trunk conductors. and for this reason the relay S5 will not be energized. 'l`lieretoie, as soon as the relay T-l lbecomes energized aiul places gr und upon the spring 76. a circuit will b'e tirnied t'roiii ground ("tlirouglitliesprings Tiandt. springs su of the relay S5. springs Si!) of the relay titi and the relay .tl to battery li. 'l`lie relay J0 will thereupon energize and light a lamp associated with an operatoi"s key. similar to the lamp 154 Aand th'e key 151'. in front of the complaint v,operator l. 'l`he operator will tlicii throw ier key' and converse with the subscriber in the manner and with the results described abo-re.

'l`he third case to he considered is that iii which the slialt wipers ot' the connector il come to rest upon a set of contacts having an opening iii the line circuit. l'nder these. conditions` when the ringer relay 125 enorgizes and connects ringing current to the line. the circuit ol tlic relay 1251, which is connected in series with ilie ringing current, will not lie closed due to the' opening in thc line and tliis relay will accordingly not en- Witli the ringer relay 125 in air energized position and tlie relay lt'i'i' deener` gized` a circuit is toriiied from ground ti through tlie interrupter 124, springs-.131

to battery B. 'lhe energization of therelay 133 closes i locking circuit for itself4 from ground (nlls through the springs 157, spi-ings 158, reliy 133 and the side switch wiper 109 (in third position) to batter B'. The energizatioi of the relay 133 will ight a lamp associated with an operators kev,

similar to the li' mp 15S-l and the key 156, in

upon an open l ne causes the calling party i to be autoiiiatiinilly connected with a complaint operator` who. upon inquiring the number being called. can inform the calling subscriber that that telephone has been reniored.

It will thus he seen that we hare devised a rery ellicieni means for automatically switching thy.` coilinectioii to an operators board in ease iii'y one ot' the switches strikes a trunk line wlicli is open.

\}'liile we liav.` illustrated our inrention in connection with an automatic telephone system of a well-ki own type employing certain wellknowii forms ot' line switches. selectors. repeaters and c iiincctois. it will` ot' course` be understood that it is equally as well adapted for iis.l iii connection with other automatic or senii-autoiiiatic systems in which ditl'creiit types of automatic switches are employed. a. oininvention is not iii any way liinitcd to the particular type of switch employed.

'liat we claini as our inreiition is:-

1. ln a telephone system. a calling and a called subscr ber`s liiic. ii xans including selector aiid con iector switches for establishing connection letween said lines, and means for signalingyfi ii operator it' said selector strikes anl opei trunk, or said connector strikes an open line.

L. ln a telephone system. a calling and a called subscrbcr`s line. means includingr trunk lilies. selictor switches. repeaters and vconnectors t'or establishing connection lie tween said lines` and means t'or signaling an operator if sa d selector strikes a trunk which is open oi either side ot' said repeatei'` or it said con iectoi strikes ar called line. which is open.

3. ln a teleplone system. a group of trunk lines. an autonatic switch adapted to connect with any one of said trunks` each o said trunks coi iprising a plurality of conductors. agroi nd normally adapted to be connected with one ol said conductors when springs 137 of the relay lti', relay 132i and .connectioii is tstablislied with said trunk, means for removing said ground iii case any the side switch wiper `1,09 (in third position) and an is open, an by for signaling of the conductors of said trunk operators position, and means controlled t e removal of said ground said operator.v

In a telephone system, a group of trunk lines, an automatic' switch adapted to connect with anyone of said trunks, each of said position, a relay with said operators position, energizing circuits for said relay, 1a short-circuit for said relay includline, an autoadaptd to establish connection line, an operators position, a relay associated with said iiosition, means for enei'gizing said relay w en said switch strikes a line which is open, an operators signal controlled by said relay, and means by which the operator may then establish connection with said switch.

n a telephone system, a line, a switch with said line, means for applying ringing current to a relay connected in series with said ringing current circuit, an operators position, a relay associated with said position, means controlled by said first relay for opening the circuit of said second relay, means for 'closing the circuit of seid Second means for establishing a talking circuit connection between two points, said circuit into normally detached circuit sections, an automatic progressively movable. switch for closing one of said sections with another, supervisory equipment individual to said switch, a control circuit for said equipment, said control circuit controlled in turn over a circuit having,lr a section individual to said last mentioned section and which conducts current which does not flow over the talking circuit.

progressively closing one ofsaid vsections with another, supervisory equipment individual to said switch, a control circuit for said equipment, auxiliary relay in said last mentioned 'not 9. In a telephone system, means for estabconnection dividedA section for controlling said cont-rol circuit, said relay energized by current which does flow over the tal ing circuit.

lishinga talking circuit connection between relay controlling said control circuit, said flow energized by current which does not over the talking circuit.

10. In a telephone system, means for establishing a talking circuit connection between two points, said circuit connection divided into normally detached circuit sections, an automatic switch for closing one of said sections with another, supervisory equipment individual current which does not flow over the talking circuit, and a circuit forcurrent controlled over said lirst mentioned section.

In a telephone system, means for estabconnection between connection divided circuit sections,

relay equipment, Said relay controlled in turn by said last mentioned section and energized by current which does -not How over the talking circuit.

12. In a telephone system,means for establishing aI circuit connection between two points, said circuit connection divided into normally detached circuit sections, an autocontrolling,r said equipment, and an auxiliary relay in said last mentioned section for controlling said' supervisory relay, 'said auxiliary relay energized by current which does not flow over the talking circuit.

1 In a autoi'iiatic switch for closing one of said sections with another, supervisory equipment auxiliary elay individual to said last mentioned section for controlling said su ervisory relay, said vauxiliary relay energized by current which ing circuit.

14. In a telephone system, means for estabdoes not flow over the talk lishing a talking circuit connection between two points, said circuit connection divided into normally detached circuit sections, an automatic switch ior closing one. of said sections with another, supervisory equipment individual to said switch, a supervisory relay for controlling' said equipment. an auxiliary relay in said last mentioned section for controlling said supervisory relay, said auxiliary relay energized hy current vwhich does not flow over the talking circuit,` the circuit for 'said current controlled over said first mentioned Section,

l5. ln a telephone system. means forestallishingr a talkingr circuit i-.onnwftion between twolioints, said circuit connection divided into normally detached circuit sections, an automatic switch for closing' one oi' said sections with another` supervisory equipment individual to said switch. and a supervisory relay for controllingl said equipment. said relay under the control oi' lioth of said sec- `vtions and energized hy current which doesl not How over the talk-ine circuit.

lti. ln a telephone s vslem. means for es tahlishine a talkingl circuit connection hetween two points. said circuit connection divided into normally detached circuit sections,'an automatic switch Jfor closing one of said sections with another` srq'iervisory equipment individual to said switch` and a supervisory 'relay for controllincy said equip ment, said relay energized hy current which does not How over the taikiuir circuit and under the control of said last mentioned seetion tor rendering it inolwrative.

17. In a telephone system, means for tahlishinc,` atalking circuit connection hetween two points, said circuit connection divided into normally detached circuit sections, an automatic. switch for closing one oi` said sections with another. supervisory equipment individual to said switch, and a supervisory rela)r tor controlling." said equipment, said relay energized hy current which does not fiow over the talking circuit and under the control of said last mentioned sec tion for preventing' the actuation of said suliervisory equipment` 1S. ln a telephone. system, means for estahlishingg,r a talking circuit connection he tween two points, said circuit connection divided into normaliy detached circuit sections. an automatic switch for closing one ol' said sections with another, supervisory equipment individual to said switch, a supervisory relay for controlling said equipment. and an auxiliaryl relay in said last mentioned section for controlling said supervisory relay .for preventing the actuation 0f said supervisory equipment1 said auxiliary relay energized hy current which does not llow over the talliincr circuit.

lil. ln a telephone system` means for establishing a tilllv'ingv circuit connection hetween two points, said circuit connection divided into normally detached circuit sections. an autanatie switch for closing' one ot said sections with another. supervisory equipn'ient ini ividnal to said switch, a supervisory relay 1er controlling said equipment, and an auxiliary relay individual to said last mentioned section for controlling' said slqiervisory rla \l tor preventing the actuation of said supervisory equipment, said auxiliary relay energized hy current which does not flow over the talking circuit. y

QU. ln a te ephonc systeni, means for estalilishingi a .alkingl circuit connection helween two p iints, said circuit connection divided into iormally detached circuit sections. an automatic switch lor closing` one ol said sez-ti( ns with another, supervisory equipment im, ividual to said switch, a supcrvisory ielay for controlling said equipment, an auxiliary relay individual to said last mentioned secion for controlling said supervisory relay, e nd a circuit for said auxiliary relay controlled over said lirst mentioned section for preventing the actuation of said supervisory equipment, the circuit for said auxiliary relay heini: energized h v current which does nrt iiow over the talking circuit.

2l. In a teephone system, means for establishing a 'zalking circuit connectitm hetween two p iints, said circuit connection divided :into :iormally detached circuit sections, an autrimatieswitch for closing,r one 0f said sectitns with another, supervisory equipment inlividual to said switch, and a supervisor) yrelay for controlling; said equipment, Au]rela energized hy current which does nct liow over the, talking circuit and under th,l control of both ot said sections for pre venting' the actuation of said supervisory el piipment.

Q2, ln a telephone system, means for ef tahlishiirc` a alking circuit connection hetweeu two points` said circuit connection divided into normally detached circuit sec -tions. an autcnultic switch for closing one oi' said sectitns with another, superuser-y equipment in lividual to said switch, and a siqwrvisor) relay for controlling Said equipment, said relay energized hy current which does mt fiow over the talking circuit and under the control of said last mentioned section i'or rendering it inoperative for preventing the :ctuution oi said supervisoryy equipment. 5'

2f-. ln a telephone system, means for establishing a ialking circuit connection between two p1 iints, said circuit connection divided into normally detached circuit sections, an autcmatic switch for closing one of. said Sectio as with another, supervisory equipment, a ielay individual to said switch for controlling said equipment, and a. control circnit fo r said supervisory relay provided with currcnt that does not How over the talking circuit, said control circuit under the control oi" said last mentioned section.

24. In a telephone system, means for tablishing a talkingr circuit connection lictween two points, said circuit connection divided into normally detached circuit tions, an automatic switch for closing one of said sections with another, supervisory equipment, a relay individiull to said switch for controlling said equipment, a control circuit for said relay, and an auxiliary relay in Said last mentioned Section for controlling said control circuit. said auxiliary relay energized hy current which does not fiow over the talking circuit.

In a telephone system, means for establishing a talking circuit connection hetw`een two points, said circuit connection 'divided into normallywdetached circuit sections, an automatic switch for closing one of said sections with another, supervism-y equipment, a relay individual 'to said switch for controlling said equipment, a control circuit for said relay, and an auxiliary relay individual to said last n'ientioned section for controlling said control circuit, said auxiliary relay energized hy current which does not flow over the talking circuit.

26. In a telephone system, means for establishing a talking circuit connection between two points, said circuit connection divided into normally detached circuit sections, an automatic switch for closing one of said sections with another. supervisory equipment, a relay for controlling said equiplnent individual to said switch, a control circuit for said relay, an auxiliary relay individual to said last mentioned section for controlling said control circuit, and a circuit for said auxiliary relay controlled over said first mentioned section, the circuit tor said auxiliary relay provided with current which doesI not pass over the talking circuit.

27. In a telephone system, means for establishinga talking circuit connection lietween two points. said circuit connection divided into normally detached circuit sections, an automatic switch for closing one of said sections with another,v supervisory equipment, a relay ior controlling said equipment individual to said switch, and a control circuit for said relay. said circuit under the control ot' both of said sections and supplied with current which does not flow over the talking circuit.

28. In a telephone system, means for cstalilishing a talking circuit connection hetween two points, said circuit connectiondivided into normally detached circuit tions, an automatic switch for closing one of said sections with another, supervisory equipment, a relay for controlling said equipment individual to said switch, and

a control circuit for said supervisory rclay provided with current which does not flow over theY talking circuit, said control circuit under the control of said last mentioned section for rendering it inoperative.

2S). In a telephone. system, means for establishing a talking circuit connection between two points, said circuit connection divided into normally detached conductor sections, an automatic switch for closing one of said sections with another, asupervisory equipment, a circuit for operating said equipment, a magnet controlled over said last mentioned section energized by current which docs not fi ow over the talking circuit, said supervisory equipment circuit under` the control of said magnet whereby if the last mentioned section is in normal condition when `the automatic switch operates said magnet is operated to control the supervisory equipment to prevent its operation. 30. In a telephone system, means for estahlishing a talking circuit connection bctween two points, said circuit connection divided into normally detached conductorsections, an automatic switch for closing one of said sections with another, a supervisory equipment, a circuit for operating said equipment, a magnet controlled over said last mentioned section energized by current which does not flow over the talking circuit, said supervisory equipment circuit under the control of said magnet whereby if the last mentioned Section is in normal condition when the automatic switch operates said magnet is operated to control the supervisory equipment to prevent its operation, and whereby if the said last mentioned sec-,tion is not in normal condition, when the automatic switch operates, said magnet leaves the supervisory equipment free to operate., and means for operating the same..

3]. In a telephone system, a calling line, a called line, means for establishing a talking circuit'connection between thc'two, said means divided into normally detached circuit sections, an automatic switch for closing one of said sections with another, means for operating said switch, a supervisory circuit associated with said first mentioned section, a signal in said circuit and automatic means for operating said signal when the said last mentioned section is out of norma-l working condition when said switch is operated, said automatic nieans operated by current that does not flow over thc talking circuit.

552. [n a tele-phone system, a. calling line, a called line, a link circuit for establishing a connection Awith the called line, an automatic switch for extending the connection from thc link to the circuit beyond, means for operating said switch, a supt'aw'isory circuit associated with said link,- and automatic means for connecting said link to Said su- A under the control of said other section` 34,. In a telephone system, means for establishing a circuit connection -hetwceu two points, said circuit connection divided into normally detached circuit sections. an automatic switch for closing one ot said sections with another, supervisory equipment individual to said switch, a control circuit for said equipment, said control circuit under the control of said last mentioned section,

lrelease cquipn'ient for said automatic switch, .and a release circuit for said switch, said supervisory equipment controlled over said release circuit.

In a telephone system, means for cstablishing a circuit connection between two points, said circuit connection divided into normally detached circuit sections, an antomatic switch for closing one of said sections with another, supervisory equipment individual to said switch, a. control circuit for said.,eqi,iipineiit, and an auxiliary relay in said last mentioned section for controlling said control circuit, release equipment for said automatic switch, and a release circuit for said switch, said supervisory equipment controlled over said release circuit,

36. In a telephone system, means for establishing' a circuit connection between two points, said circuit connection divided into normally detached circuit sections, an auto matic switch for closing one of said sections with another, suliervisory equipment individual to said switch, a control circuit for said equipment, an auxiliary relay individual to saidv last mentioned section for controlling said control circuit, release equipment for said automatic switch, and a release circuit for said switch, said super- .yisdiry equipment controlled over said release circuit.

37. In a telephone system. means for l talilisliingg; a circuit connection lictwcen two points, said circuit connection divided intov normally detached circuit sections` an alito-- iiiaticswitch for closing' oneot' said sections with another. supervisory equipuient individual' to said switch, a control circuit for said equipment, an auxiliary relay iii said last mentioned section ior controlling said control circuit, a circuit for said auxiliary relay controlled over said one section, release equipment for said. automatic switch, and a release circuit for said switch, said supervisory eqnipinail controlled over said rclease circuit.

ISS. ln a teli phone system, means for estalilisliinn a ci lcuit connection lietween two points. said ii-cuit connection divided into normally deiacheifl circuit sections, an auto matic sa ilch i'i r closing one ot' said sections with another. supervisory equipment indii'idual to said switch, a control circuit for said equipment, said circuit under the. control ot lioth oi said sections, release equipment l'l-il said automatic switch, and a release circuit-ifnsaid switch, said Vsupervisory equipment controlled over said rclease cii cuit.

59. ln a tcleihone system, means for establishing' a ciiciiit connection between two points, said ciicuit connection divided into normally detac ied circuit sections, an alitoniatii: switch fo r closing one of said sections with another. iupervisory equipment individual to said switch, a control circuit for said equipment, said control circuit under the conti-ol of s:.id last mentioned section for rendering,r it in iperative,` release equipment for said autom: tic switch, cuit for said su itch, said supervisoryequipment controlled over said release circuit.

40. In a teleihone system, means for estalilishiingr a cii mit connection between two points,`said ciriiit connection divided into normally detached circuit sections, an automatic switch to closing one of said sections with another, supervisory equipment ndividiial to said si ritcli, a supervisory relay for controlling said equipment, said rela;1 under the control otl 'aid last nicntioncd section, release eqiiipine it t'or said automatic switch, and a, release iircuit lioi said switch. said supervisory equipment controlled over said release circuit.

41. In a telephone system. ineansior cstalilisliing; a cir-uil connection lietwcen two points. said ciri uit connection divided into normally delacl ed circuit sections. an alitoiiiatic switch toi closingL one olA said sections with another. ipervisory equipment individual to said switch, a supervisory relay for controlling iaid equipment, an auxiliary relay in said ast mentioned sect-ion for controlling' said supervisory relay, release equipment for s iid ,automatic switch, and a` release circuit iur said switch, said si|pc.r visory equipment controlled oi'er said release. circuit.

42. .ln a telephone system, means foi'estalilisliinj; a cir( uit connection between two points, said circuit connection divided into normally detacliid circuit sections, an aiitomatic switch for closing one ot' said sections with another, sipcrvisory equii'inicnt individual to said switch, a supervisory relay and a release cirfor controlling said equipment, an auxiliary relay individual to said last mentioned section for controlling said supervisory relay, release eequipment for said automatic switch, and a. release circuit for said switch, :aid supervisory equipment controlled over said release circuit.

43. In a telephone systeni. 4means for establishing a circuit connection between two points, said circuit connection divided into normally detached circuit sections, an uitomatic switch for closing one of said with another, su] ervisor v equipment individual to said switch` a supervisory relay `for controlling;r said equipment` an auxiliary relay in Said last mentioned Section for controlling said supervisory relay, a. circuit for Said auxiliary relay controlled over said first mentioned section` release e uipment for said automatic switch, and a re ease circuit for said switch, said supervisory equipment controlled over said r alease'circuit.

44. ln a telephone system, means for establishing a circuit connection between two points, said circuit connection divided into normally detached circuit sections, an automatic switch for closing one of said Sections with another, supervisory equipment individualto said switch, a supervisory relay for controlling said equipment, said relay under the control of both of said sections, release equipment for said automatic switch, and a release circuit for said switch, said supervisory eqi'lipment controlled over Said release circuit.

45. ln a telephone system, means for establishing a circuit connection between two point-s, saitircuit connection divided into normally ietached 'circuit sections, an automatic switch for closing one'of said sections with another, supervisory equipment individual, to said switch, a supervisory relay l'or controllin,f ,1r said equipment, said relay under the control ot' said last mentioned section for rendering it inoperative, release equipment. torsaid automatic switch, and a release circuit for said switch, said supervisor-y equipment controlled over said release circuit.

46. l'n a tele'pl'ione system, means for es-V tablishing a circuit connection between two points, said circuit connection divided into normally detached circuit sections, an automatic switch for closing one of said. sections with another, supervisory equipment individual tosaid switch, a supervisory relay for controlling said equipment, said relay under the control of said last mentioned section for preventing the actuation of said supervisory equipment, release equipment for said autor' atic switch, and a release circuit for said switch,-saimsupervisory equipment controlled over said release circuit.

47. In a telephone system, means for establishing ai circuit connection between two matic switch for points, said circuit connection divided into normali)Y detached circuit sections, an automatic switch for closing' one ot' said sections with another, supervisory equiljnnent individual to said switch, a supervisory relay for cosntrollimar said equipment, au auxiliary relay in said last mentioned section .for controlling said sulwrvisory relay for preventing the actuation ot' said. sul'iervisory equipmentlrelease equipment for said automatic Swita and a release circuit for said switch, said supervisory equipment controlled over said release circuit.

48. ln a telephone system, means for eS- tahlishiner a circuit connection between two points, said circuit connection divided into nor-mall)r detached circuit scctions,'an automatic switch lor closing! one of said sections with another, supervisory equipment individual to said switch, a supervisory relay for col'itrolling said equi pn'ient, an auxiliary relay individual to said last mentioned section` for controlling said supervisory relay for preventing' the actuation ot' said super visory equipment, release equipment for said automatic switch, and a release circl'iit for said switch, said supervisory equipment controlled over said release circuit'.

49. ln a telephone system, means for eS- tblishing acircuit connection between two points, sani-circuit connection divided into normally detached circuit sections, an automatic switch for closing' one ot' said-sections with another, supervisoryY equipment individual to said switch, a supervisory relay for cmitrolling,` said equipment, an auxiliary relay individual to said last mentioned section for controlling said supervisory relay, a circuit for said auxiliary relay controlled over said first mentioned section for preventing the actuation olf said supervisory equipment, releasc equipment tor said. automatic switch, and a. release circuit for Said switch, said supervisoiy equipment controlled over said release circuit.

50. ln a telephone system. means'tor estab# lishing' a circuit connection het-Ween two points, said circuit connection divided into normally detached circuit sections, an auto` maticswitch for closing one ot said sections with another` supervisory equipment individual to said switch, a. 'supervisory relay for controlling said wluil'nncnt, said relay Under the control ot both .of said sections for preventing the actuation oi said supervisory equipment, release equipment for matic switch, and a release circuit for said switch, said supervisory equipment controlled over said release circuit.

51. In a telephone system, means for establishing a circuit connection between two points. saidkcircuit connection dii ein into normally detached circuit. sections, a"n autoclosing one of said sections with another, supervisory eqiipment indisaid autovldual to said switch, a supervisory relay for controlling said equipment. said relay under the control otE said last mentioned section for rendering it inoimrative for preventing,r the actuation of said supervisory equii'n'nent, release equipment for said automatic, switch. and a release circuit for said switch. said supervisory equipment controlled over said release cilf'cuit.

l'ii a telephone system. means for establishing.P a circuit connection between two points. said circuit connection divided into noruially detached circuit sections, an automatic switch l'or closing one of said sections with another. supervisory equipment, a relay for controlling' said equipment individual to said switch. a control circuit for ,said relay. said control circuit under the control of said last mentioned section. release ei'piipnient for said auton'iatic s..itcb. and a release circuit for said switch. said suiiervisory equipment controlled over said release circuit. I

5?. Tn a telephone system. means for establishingr a circuit connection between two points. said circuit' connection divided into normally detached circuit sections. an automatic switch for closin; r one o'f said sections with another. supervisory equipment. a relay t'or controlling said equipment individual to said switch. a control circuit; for' said relay; au auxiliary relaiT in said last mentioned section for controlling said control circuit. release equipment for said automatic switch. ind a release circuit for said switch. said supervisory equipment cont'rolled oi'er said release circuit. Y

."i-t. Tn a telephone system. means for.' establishiiuer a circuit connection between two points. said circuitconnection divided into normally detached circuit sections. au alitoniatic switch 'for closingl one of said sectiffns with another. suiwrvisory equipment, a relay for controllingT said equipment indii'id-iial to said switch. a control circuit fol said relay. an auxiliary relay individual to said last' mentioned section for controlling said control circuit. release eqliipiiient for .said ,automatic switch. and a release circuit for said switch. said supervisory ei'juipinent controlled over said release circuit.

ln a telephone system. meansl for establishiiuLV a circuit connection between two points. said circuit connection divided into normally detached circuit sections. an automatic switch l'or closing one ol' said sections with anotliir. supervisory equipment. a relay l'or controlling.: said equipment individual to said switch. a control circuit' for said relay. an auxiliarv relay individual to said last' mentioned section l'or controllingr said control circuit. a circuit l'or said auxiliary relay controlled over said first n'ientionwl section. release equipment for said automatic switch, and a release circuit for said switi h, said supervisory equipment controlled over said release circuit.

56. ln a ielephone system, means for establishing.,Y a circuit connection between two points. said iireuit connection divided into normally detiched circuit sections. an automatic switch lior closingr one of said sections with another supervisory equipment, a relay for controlling: said equipment individual to said switch. a control circuit for said relay. sa d circuit iimler the control of both of said ari-tions. releaseI equipment for said automate switch, and a release circuit for said switih, said supervisory equipment controlled oi' ir said release circuit.

5T. l'ii a telephone. system, means Jfor establishing a circuit connection between two points, said circuit connection divided into normally detached circuit sections, an automatic siiiteh for Closing one of said .sections witl another, supervisory equipment, a relalr for controlling said equip nient individual to said switch, a control circuit Jf'or said relay, said control circuit under the cintrol of said last; mentioned section l'or rinderiuir it inoperative. release equipment l'tr said automatic switch. and a release circuit for said switch. said supervisory eqiipnient controlled over said release circili 1.

V58. In a 'Telephone system. means for establishing a circuit connection between tivo points. .said circuit connection divided into normally detached conductor sections. an automatic switch for closingr one ot said sections with another. a supervisory equipment, a circ'iit for operating said equipment. .a magnet controlled over said last mentioned se "tion, said supervisory equipment circuit mder the control of said magnet whereby t' the last mentioned section is in normal c mdition when the automatic switch operates said magnet is operated to control the supervisoiy equipment to prevent its operation relea'se equipment for said automat c switcbaand a release circuit for said switch, said siq'iervisory equipment controlled ov Ir said release circuit.

59. In a elephone system, means for establishing a circuit connection between ytwo points. .said circuit connection divided t 1 i l seid magnet leaves the supervisory equipment free to operate, and' means for operating the same, release equipment for said automat-ic switch, and a release circuit for 5 said switch, said supervisory equipment controlled over said release circuit.

60. In a telephone system, a calling line, a called line. means for establishing a circuit connection between the two, said means divided into normally detached circuit sec'- tions. an automatic switch for 'closing one of said sections with another, means for operating said switch, a supervisory circuit associated with said first mentioned section, a signal in said circuit and automatic means for operating said signal when the said last mentioned section is out of normal working'condition when said switch is operated. release equipn'ient tor said automatic switch, and a release circuit for said switch, said sul'iervisory equipment controlled over said release circuit.

G1. ln a telephone system, a calling line, a calledline, a link circuit .for establishingr a connection with the called line, an automati l switch for extending the connection from the link to the circuit beyond. means for operating,lr said switch.l a supervisory eir cuit associated with Said link. automatic means for connecting said link to said supervisory circuit if the circuit beyond is defectivwat theI time the switch is operated, release equipment for said automatic switch, and .i release circuit for said switch. said supervisory circuit controlled over said release circuit.

62, ln a telephone system, means forestablishng a talking: circuit connection between two points. said circuit connection divided into normally detached sections, an automatic switch t'or extending a talkingr circuit from one ol said sections to another, electromaenelically controlled supervisory mechanism associated with said switch. a circuit i'or said mechanism. means for opi 'atively energizing said circuit for operating said mechanism it' the automatic .switch linds the talking). circuit ot one ot' the sections open. means for rendering the circuit olA said iinechanism inoperative'it the switch finds the talking circuit of one ol the sectionsl closed. release. equipment lor said automatic switch. andai release circuit i'or said switch. said supervisory mechanism controlled over said release circuit.

uit. ln a telephone system. means for es* tablishing lr a circuiti connection between two points. said circuit connection divided into l-uormally detached circuit sections. au auto` cui matic switch l'or closing one ot' said sections i with another. supervisory equipment. a conlIrol circuit. for said equipment. said control :circuit under thc control ol' said last luentioned section. release equipment for said if', automatic switch, and a release. circuit for said switch, said su ervisory equipment controlled over said re ease circuit.

64. In a telephone system, means for establishing a. circuit connection between two points, said circuit connection divided into normally detached circuit sections, an automatic switch for closingr one of said sections with another, supervisory equipment rindividual to said switclua control circuit for said equipment, said control circuit under the control of said last mentioned section, and a busy test circuit for said switch, said supervisory equipment controlled over said busy test circuit.

(if. In a telephone system. means for establishing a circuit connection between two points. said circuit connection divided into normally detached circuit sections. an alitomatic switch forclosing one of said sections with anotlier, supervisory equipment individual to said switch, a control circuit for said equipment, an auxiliary relay in said last mentioned section for controlling said control circuit, and a busy test circuitfor said switch. saidsupervisor)r equipment controlled over said busy test circuit.

(i6. in a telephone system. Vmeans for establishilugr a circuit connection between two points. said circuit connection divided into normally detached circuit sections. an automatic switch for closing one of said sections with another. supervisory equipment individual to said switch. a control circu'rt for said equipment. an auxiliary relay individual to said last mentioned section for controlling said control circuit. and a busy test circuit for said switch, said supervisory equipment controlled over said busy test circuit.

(ST. Tn a telephone system. means for tablishinf; a circuit connection between two points. said circuit connection divided into normally detached circuit sections. an autolnatic switch for closing.r one of said sections with another. sulwrvisory equipment individual to said switch. a control circuit for said equipment. an auxiliary relay in said last mentioned section for controlling said control circuit. and a circuit for said auxiliary relay` controlled over said first men- 'tioned section. und a busy test circuit for said switch. said supervisory equipment controlled over said busy test circuit.

HH. ln a telephone systennineans for establishinz;r a circuit connection between two points. said circuit connection divided into normally detached circuit sections/an automatic switch for closing one of said sections with another. supervisory equipment indi vidnal to said switch. a control circuit for said equipment. said circuit under the control ol both ol said sections. and-a busy test circuit l`or said switch. said supervisory equipment controlled over said busy test circuit.

(if). In aftelephone system. means for es tablishing a circuit connection between two points,y said eirizuit; eonneirtion divided into normally detached circuit sections. an automatic switch for closing one of said sections with another. supervisory equipment individual to said switch. a eoutrol eireuit. for said equipment. said eouirol ereut under the control of said last mentioned seetion for rendering it inoperative. and a busy test circuit t'or said switeh. said supervisory equipment (,'ontrolled over said busy test eircuit. i

T0. ln a telephone system. means for es tablishingr a circ-uit eonneetion between two points. said eireuit eonneeliou divided into normally detaehed eireuit seetions. an autoinatie switeh l'or elosing one of said sei-tions with another. supervisory equipment individual to said switrh. and a snpervisonv relay for eont|'ollin; said equipment. said relay` under the eoulrol oll said last mentioned sei-tion. and a busy lest eireuit l'or said switeh. said supervisory equipment eon trolled over said busy test eirruit.

Tl. ln a telephone system. means for establishing a eireuil eonueetion between two points. said elreuil eonneetion divided into normally i'tetarhed eireuit sel-lions. an alltoumtie switeh for elosiutl' one ot said seetions with another. supervisory equipment individual to" said switeh. a supervisory relay for eontrolling said equii'nuent. au auxiliary relay in said last mentioned seetion tor eontrolling said supervisory relay. and a busy test eircuit toi` said switch. said supervisory equipment controlled over said busy test circuit..

72. ln a telephone system. means l'or establishing rireuit eonneetion between two points. said eireuit, eonneetion divided into normally detaehed eireuit seetions. au automatie switeh for closing one of said seelious with another. su|wrvisory equipment individual to said switeh. a siqnrvisory relay 'For eoutrolling said equipment. an auxiliary relay individual to said last mentioned seetion I'or eoutrolling said sularvisoev relay. and a busy test. eireuit for said switeh. said slqwrvisory equipment controlled over said busy test circuit,

7?. ln a telephone system. means for establishingr a eireuit. 'eonneetion between two points. said eireuit eonneetion divided into normally detaehed eireuit sections. au alitomatie switeh l'or elosing one ot' said seetions with another. sulwrvisory equipment individual to said switeh. a slq ervisory relay I'or eontrolliuer saidV equipment. an auxiliary relay in said last. mentioned seetion for eonlrolliug: said supervisory relay. a ereuit for said auxiliary relay eontrolled over said lirstLmeutioned seetion. and a busy test eireuitl'or said switeh. said supervisory equipment eontrolled over 'said busy test. eireuit.

Tl. ln a telephone system, means` for es;1J tablishing a circuit. eonuection between two points,sail cir( uit eonnection divided into norn'ially detaeli ed circuit sections. an automatic switch 'l"o| closing' one of said sections with another. sipervisory equipment indi vidual to said sv iteh. a supervisory relay for eontrolling said equipment. said relay under the eontrol of both ot' said sections. and a busy test eireuit for said switeh. said supervisory equipn'lent eoutrolled over said busy test (tirellit.

T5. lu a telephone system. means for e5'- tablishing a eiruit eonueetion between two points. saidaireuit eonneetion divided into normally detaeled circuit sei-tions. au auto'- mal ie switeh to l\'elosinf Y one ot said seetions with another. fupervisory equipment individual to said switeli. a supervisory relay l'or egmtrollingll said equipment. said relay under the eontrol of said last mentioned sei-tion for rendering it inoperative. and a busy test eireuiy for said switch. said supervisory equipme it eontrolled over said busy test eireuit.

7G. lu a tele )hone system. means tor establishiug' a eileuit eonnertiou between two points. said eilruit eonneetion divided into normally detae led eirenit seetions. au automatie switeh t relosiug1one ot' said seetions with another. aipervisory equipment indi vidual to said s w'itrll. a sulwrvisory relay for eontrolling `sail equipment. said relay un der the eoutro ot' said last mentioned seetion for preventing the aetuation of said supervisory equipment. and a busy test eir enit for said switeh. said supervisory equipment eontrollei over said busy test circuit.

TT. ln a teh phone system. means for establisbing a ei :'cuit eon-neetion between two points. said ei enit eonnection divided into normally detalhed eireuit sections. an auto malie switeh for elosing one of said seetions with another. supervisory equipment individual to said switeh. a supervisory relay tor eontrolliug.l said equipment. an auxiliary relay in said l: st mentioned section for eontrolling said s ipervisoiy relay for preventing.| the aetuation ot' said supervisory equipment. and a bi sy test eireuit for said switeh. said supervisory equipment controlled over said busy test :ii-cuit.

7S. ln a tel lphone system. means for establishing a ereuit eonueetion between two points. said efreuit eonneetion divided into normally deta 'hed eireuit seetions. an alitomatie switch tor elosing one ot said sections with another. supervisory equipment indi vidual to said .u\'itel1.a supervisory rela)` for eoutrollintr sa d equipment` an auxiliary relay individual to said last mentioned seetion for eoutrolling.r said supervisory relay for preventing: the actuation of said supervisiafy equipment. ai d a busy test eiremt tor said switeb. said supervisory equipment eontrolled over s: id busy test eireuit.

T0. lll a te ephone. system. means lor es .555 vidual to said switch.

tablishing a circuit connectionbetween two points. said circuit connection divided into normally detached circuit sections, an automatic switch for closing one of said sections with another, slmervisory equil'nnent individual to said switch. a supervisory relay Jfor controlling said equipment, an auxiliary relayr iiuliv-idual to said last meu* tioned section for ctmtrolling` said supervisory relay, a circuit for said auxiliary re lay controlled.oveiusaid tirst mentioned secs tion ior preventin;4 )r the actuation of said supervisory equipment. and a busy test circuit for said switch, said supervisory equipment controlled over said busy test circuit.

HU. ln a telephone system, means for es- -tablisliing a circuit connection between two points. said circuit connection divided into normally detached circuit sections. an untomat-ic switch for closing one of said sections with another. Slq'iery-'isorv equipment individualto said switch. a si'l'pcrvisory relay tor controllin;r said equil'iment. said relay vinder the control of both of said sections i'or preventing' the actuation ot said super visory equipment. and a busy test circuit for said switch. said supervisorv equipment con-A trolled over lsaid busy testcircuit. l

Si. In a telephone system, means for establishirncl a circuit connection between two points. said circuit connection divided into normally detached circuit sections. an antoimatic switch, for closing one of said sections with anotjer'. supervisory equipment indifor controlling said equipment. said relay under the control of said last n'ientioned section for rendering it inoperative for preventingg the actuation of said supervisory 40 equipment. and a busy test circuit for said switch. said supervisory equipment eontrolled over said busy test circuit.

Tn a telephone system, means for establishing a circuit connection het-wee'n two points. said circuit connection divided into norniallv detached circuit sections. an anto matic. switch for closingr one of. said sections' with another, supervisory equipment. a relay For controlling said equipment individual to' said switch. a' control circuit for said relay. said control vcircuit under the control ot said last mentioned section. and a busy test circuit for said switch. said supervisory equipment controlled over said busy test circuit.

8?.. Tn a telephone system. means for cstablishiu; r a circuit connection between two points. said circuit connection divided into normally detached circuit sections. an alitomatic switch for closing' one of said sections with another. supervisory equipment. a. relav for controlling' said equipment individual to said switch. a control circuit for su id relay. an auxiliary relay in said last mentioned section for controlling said control a supervisory relay' circuit, and a busy test circuit for said switch, said su|jieryisory equipment' controlled over said busy test circuit.

Si. In a telephone system, means for establislling` a circuit connection between two points, said circuit connection divided into normally detached circuit sections, an automatic switch for closing one ot' said sections with another, sulwrvisory equipment. a relay for controllingI said equipment individual to said switch. a control circuit for said relay, an auxiliaryv relay individual to said last mentioned section tor controlling Said control circuit. and a busy test circuit for said switch. said slqnrrvisory equipment con- 30 trolled over said busy test circuit.

S5. Tn a telephone system. means for cstablishing a circuit connection between two points. said circuit connection divided into normally detached circuit sections, an auto- 35 matic switch for closing one ot' said sections with another. supervisory equipment, a relay't'or controlling said equipment individual to said switch. a control circuit for said relay. an auxiliary relay individual to lsaid last mentioned section for controllingr said control circuit. a circuit for raid auxiliary relay controlled over said first mentioned section. and a busy test circuit for said switch. said supervisory equipment controlled over said busy test circuit'.

96. Tn a telephone system, means tor establishing; a circuit connection between two points. said circuit connection divided into normally detached lcircuit sections. an alitomatic switch for closing;I one of said sections with another, superv-'isory equipment. a relay for controlling said equipment individual to said switch.. a control circuit for said relay. said: circuit under the control of both of said sections` and a busy test circuit for said switch. said supervisory equipment controlled over said busy test circuit.

87. Tn a telephone system. means for establishing n circuit connection between two points. said circuit connection divided into n ally ikitnchcd circuit sections. an automatic switch for closingr one of said sections with a'nother. supervisory equipment. a relay fmcontrollincr said equipment individual to said switch. a cont-rol circuit for said relay. said control circuit under the control of said last mentioned scctionfor renderingr it inoperative. and a busy test circuit for said switch, said supervisory equipment controlled over said busy test circuit.

8S. Tn a telephone system. means for establishing a circuit connection between two points. said circuit connection 'divided into normally detached conductor sections. an automatic switch` for closing one of said scctilens with another.I a supervisory equipment. a circuit for operating said super-A visorv equipment, a magnet controlled over said last mentioned section, said supervisory 13o equipment circuit under the control of said magnet whereby if the last mentioned scction is in normal condition when the automatic switch operates said magnet is operated to control the supervisory equipment to preventits operation1 and a busy test circuit for said switch, said supervisory equip ment controlled over said busy test-circuit.

89'. In a telephone system, means for es tablishingr a circuit connection between two points, said circuit connection divided into normally detached conductor sections, an

automatic switch for closing one ot said sect-ions with another, a supervisory equipment, a circuit for operating;r said equip.- ment, a magnet controlled over said last mentioned section, said supervisory equipment circuit under the control of said magnet whereby if the last mentioned section is in normal condition when the automatic switch operates said magnet is operated to control the supervisory equipment to prevent its operation, and whereby if the said last mentioned section is not in normal' condition, when the automatic switch operates, said magnet leaves the supervisory equipment free to operate, means for operating the same, and a busy test circuit for said switch, said supervisory equipment controlled over said busy tcst circuit.

9U. In a 'telcphonc system, a calling,r line, a called line, means for establishing a circuit connection between the' two, said means divided into normally detached circuit sections, anautomatic switch for closing one of said sections with another, means for operating said switch, a supervisory circuitassociated with said first mentioned section, a signal in said circuit and automaticrmcans for operating said signal when the said last mentioned section is out of normal working.,lr condition when said switchis olwratcdgaml a busy test circuit Jor said switch, said supervisory circuit controlled over said busy test circuit.

91. In a telephone system, a calling line, a called line, a link circuit for establishing a connection witlr the called line, an automatic switch for extending the connection one of said sectinns to another, electromagnetically controlled Isupervisory mechanism associated with said switch, said mechanism, means for operatively energizing said rircuit for operatingr said 'mechanism if thi automatic switch finds the talking circ-uit (f one of the sections open, and means for rendering the circuit of said mechanism inoperative if the switch finds the talkingr cir( uit of one of the sectionsclosed, and a ousy test circuit for said switch, said supervisory mechanism controlled over sait, busy test circuit.

93. In a teler hone system, means for establishing a circuit connection between two points. said circuit connection divided into normally detacl ed circuit sections, an automatic `switch for closing one of said sections with another, supervisory equipment, a control circu t for said equipment, said control. circuit i nder the control of said last mentioned section, and a busy test circuit for said switch. said supervisory 'equipment controlled over said busy test circuit.

Signed by` us at Chicago, Illinois, this 20th day of November, 1913.

GEORGE A. YANOCHOIVSKI. 'HARRY I". HERSHEY. W itnesscs lgI. W. Ilmnmi, Amon (law/uio.

a circuit for

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